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Alkathiry HA, Alghamdi SQ, Sinha A, Margos G, Stekolnikov AA, Alagaili AN, Darby AC, Makepeace BL, Khoo JJ. Microbiome and mitogenomics of the chigger mite Pentidionis agamae: potential role as an Orientia vector and associations with divergent clades of Wolbachia and Borrelia. BMC Genomics 2024; 25:380. [PMID: 38632506 PMCID: PMC11025265 DOI: 10.1186/s12864-024-10301-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 04/11/2024] [Indexed: 04/19/2024] Open
Abstract
BACKGROUND Trombiculid mites are globally distributed, highly diverse arachnids that largely lack molecular resources such as whole mitogenomes for the elucidation of taxonomic relationships. Trombiculid larvae (chiggers) parasitise vertebrates and can transmit bacteria (Orientia spp.) responsible for scrub typhus, a zoonotic febrile illness. Orientia tsutsugamushi causes most cases of scrub typhus and is endemic to the Asia-Pacific Region, where it is transmitted by Leptotrombidium spp. chiggers. However, in Dubai, Candidatus Orientia chuto was isolated from a case of scrub typhus and is also known to circulate among rodents in Saudi Arabia and Kenya, although its vectors remain poorly defined. In addition to Orientia, chiggers are often infected with other potential pathogens or arthropod-specific endosymbionts, but their significance for trombiculid biology and public health is unclear. RESULTS Ten chigger species were collected from rodents in southwestern Saudi Arabia. Chiggers were pooled according to species and screened for Orientia DNA by PCR. Two species (Microtrombicula muhaylensis and Pentidionis agamae) produced positive results for the htrA gene, although Ca. Orientia chuto DNA was confirmed by Sanger sequencing only in P. agamae. Metagenomic sequencing of three pools of P. agamae provided evidence for two other bacterial associates: a spirochaete and a Wolbachia symbiont. Phylogenetic analysis of 16S rRNA and multi-locus sequence typing genes placed the spirochaete in a clade of micromammal-associated Borrelia spp. that are widely-distributed globally with no known vector. For the Wolbachia symbiont, a genome assembly was obtained that allowed phylogenetic localisation in a novel, divergent clade. Cytochrome c oxidase I (COI) barcodes for Saudi Arabian chiggers enabled comparisons with global chigger diversity, revealing several cases of discordance with classical taxonomy. Complete mitogenome assemblies were obtained for the three P. agamae pools and almost 50 SNPs were identified, despite a common geographic origin. CONCLUSIONS P. agamae was identified as a potential vector of Ca. Orientia chuto on the Arabian Peninsula. The detection of an unusual Borrelia sp. and a divergent Wolbachia symbiont in P. agamae indicated links with chigger microbiomes in other parts of the world, while COI barcoding and mitogenomic analyses greatly extended our understanding of inter- and intraspecific relationships in trombiculid mites.
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Affiliation(s)
- Hadil A Alkathiry
- Imam Mohammad Ibn Saud Islamic University, Riyadh, Saudi Arabia
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, 146 Brownlow Hill, Liverpool, L3 5RF, UK
| | - Samia Q Alghamdi
- Department of Biology, Faculty of Science, Al-Baha University, P.O.Box1988, Al-Baha, 65799, Saudi Arabia
| | - Amit Sinha
- New England Biolabs, Ipswich, Massachusetts, 01938, USA
| | - Gabriele Margos
- National Reference Centre for Borrelia, Bavarian Health and Food Safety Authority, Veterinärstr. 2, Oberschleissheim, 85764, Germany
| | - Alexandr A Stekolnikov
- Laboratory of Parasitic Arthropods, Zoological Institute of the Russian Academy of Sciences, Universitetskaya embankment 1, St. Petersburg, 199034, Russia
| | | | - Alistair C Darby
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, 146 Brownlow Hill, Liverpool, L3 5RF, UK
| | - Benjamin L Makepeace
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, 146 Brownlow Hill, Liverpool, L3 5RF, UK
| | - Jing Jing Khoo
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, 146 Brownlow Hill, Liverpool, L3 5RF, UK.
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Smit A, Mulandane FC, Wojcik SH, Horak IG, Makepeace BL, Morar-Leather D, Neves L. Sympatry of Amblyomma eburneum and Amblyomma variegatum on African buffaloes and prevalence of pathogens in ticks. Ticks Tick Borne Dis 2023; 14:102247. [PMID: 37651847 DOI: 10.1016/j.ttbdis.2023.102247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 07/20/2023] [Accepted: 08/17/2023] [Indexed: 09/02/2023]
Abstract
The Amblyomma genus is represented on the African continent by 24 species, out of which 17 are known to occur in different ecological niches of southern Africa. Amblyomma, known for their aggressive hunting behaviour and aptitude as pathogen vectors, are of main concern to travellers, mainly in rural and conservation areas of Africa. In this study, we highlight the overlapping distribution of Amblyomma eburneum and Amblyomma variegatum found on African buffaloes (Syncerus caffer) at Coutada 11, Central Mozambique. In total, 1,039 Amblyomma ticks were collected and morphologically identified using taxonomic keys, and genomic DNA was extracted. They were subjected to reverse line blotting for pathogen identification followed by molecular analysis (COI sequencing) of both tick species. Pathogens such as Ehrlichia ruminantium, Anaplasma centrale, Theileria sp., Babesia sp. and Rickettsia africae were detected, of which R. africae is zoonotic. Ehrlichia ruminantium, R. africae, Theileria mutans and Theileria velifera are well-established pathogens transmitted by Amblyomma ticks; however, Anaplasma spp. and Babesia spp. are not, suggesting residual parasite DNA in the bloodmeal. Little is mentioned in the literature about A. eburneum, including its role as a vector and reservoir for pathogens. In Mozambique A. eburneum is currently restricted to wildlife but the spread of the tick may be observed given the climate change that is occurring. The infection rates for the pathogens in both Amblyomma tick species were lower than expected, but this may be due to the low host density in the forest niche and the innate immunity of these hosts. With the propensity of ticks of the Amblyomma genus to form parapatric distributions, the mechanisms that allows for the overlapping distribution of these two Amblyomma species while maintaining tick species identity is of great interest.
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Affiliation(s)
- Andeliza Smit
- Tick Research Group, Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, 0110, South Africa.
| | - Fernando C Mulandane
- Biotechnology Center, Eduardo Mondlane University, Av. Moçambique Km 1.5, Maputo, Mozambique
| | - Stephané H Wojcik
- Tick Research Group, Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, 0110, South Africa
| | - Ivan G Horak
- Tick Research Group, Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, 0110, South Africa
| | - Benjamin L Makepeace
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, 146 Brownlow Hill, Liverpool L3 5RF, United Kingdom
| | - Darshana Morar-Leather
- Tick Research Group, Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, 0110, South Africa
| | - Luis Neves
- Tick Research Group, Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, 0110, South Africa; Biotechnology Center, Eduardo Mondlane University, Av. Moçambique Km 1.5, Maputo, Mozambique
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Floriano AM, Batisti Biffignandi G, Castelli M, Olivieri E, Clementi E, Comandatore F, Rinaldi L, Opara M, Plantard O, Palomar AM, Noël V, Vijay A, Lo N, Makepeace BL, Duron O, Jex A, Guy L, Sassera D. The evolution of intramitochondriality in Midichloria bacteria. Environ Microbiol 2023; 25:2102-2117. [PMID: 37305924 DOI: 10.1111/1462-2920.16446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 05/31/2023] [Indexed: 06/13/2023]
Abstract
Midichloria spp. are intracellular bacterial symbionts of ticks. Representatives of this genus colonise mitochondria in the cells of their hosts. To shed light on this unique interaction we evaluated the presence of an intramitochondrial localization for three Midichloria in the respective tick host species and generated eight high-quality draft genomes and one closed genome, showing that this trait is non-monophyletic, either due to losses or multiple acquisitions. Comparative genomics supports the first hypothesis, as the genomes of non-mitochondrial symbionts are reduced subsets of those capable of colonising the organelles. We detect genomic signatures of mitochondrial tropism, including the differential presence of type IV secretion system and flagellum, which could allow the secretion of unique effectors and/or direct interaction with mitochondria. Other genes, including adhesion molecules, proteins involved in actin polymerisation, cell wall and outer membrane proteins, are only present in mitochondrial symbionts. The bacteria could use these to manipulate host structures, including mitochondrial membranes, to fuse with the organelles or manipulate the mitochondrial network.
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Affiliation(s)
- Anna Maria Floriano
- Department of Biology and Biotechnology 'L. Spallanzani', University of Pavia, Pavia, Italy
- Université de Lyon, Université Lyon 1, CNRS, VetAgro Sup, Laboratoire de Biométrie et Biologie Evolutive, Villeurbanne, France
| | - Gherard Batisti Biffignandi
- Department of Biology and Biotechnology 'L. Spallanzani', University of Pavia, Pavia, Italy
- Department of Clinical, Surgical, Diagnostic and Pediatric Sciences, University of Pavia, Pavia, Italy
| | - Michele Castelli
- Department of Biology and Biotechnology 'L. Spallanzani', University of Pavia, Pavia, Italy
| | - Emanuela Olivieri
- Department of Biology and Biotechnology 'L. Spallanzani', University of Pavia, Pavia, Italy
- Pavia Department, Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna, Pavia, Italy
| | - Emanuela Clementi
- Department of Biology and Biotechnology 'L. Spallanzani', University of Pavia, Pavia, Italy
| | - Francesco Comandatore
- Department of Biomedical and Clinical Sciences, Pediatric Clinical Research Center 'Romeo ed Enrica Invernizzi', University of Milan, Milan, Italy
| | - Laura Rinaldi
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, CREMOPAR Regione Campania, Naples, Italy
| | - Maxwell Opara
- Zoonotic Parasites Research Group, Department of Parasitology and Entomology, Faculty of Veterinary Medicine, University of Abuja, Abuja, Nigeria
| | | | - Ana M Palomar
- Center of Rickettsiosis and Arthropod-Borne Diseases (CRETAV), San Pedro University Hospital, Center of Biomedical Research from La Rioja (CIBIR), Logroño, Spain
| | - Valérie Noël
- MIVEGEC (Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle), University of Montpellier (UM), Montpellier, France
| | - Amrita Vijay
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - Nathan Lo
- School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia
| | - Benjamin L Makepeace
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Olivier Duron
- MIVEGEC (Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle), University of Montpellier (UM), Montpellier, France
| | - Aaron Jex
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Melbourne, Victoria, Australia
| | - Lionel Guy
- Department of Medical Biochemistry and Microbiology, Science for Life Laboratories, Uppsala University, Uppsala, Sweden
| | - Davide Sassera
- Department of Biology and Biotechnology 'L. Spallanzani', University of Pavia, Pavia, Italy
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Noll M, Wall R, Makepeace BL, Newbury H, Adaszek L, Bødker R, Estrada-Peña A, Guillot J, da Fonseca IP, Probst J, Overgaauw P, Strube C, Zakham F, Zanet S, Rose Vineer H. Predicting the distribution of Ixodes ricinus and Dermacentor reticulatus in Europe: a comparison of climate niche modelling approaches. Parasit Vectors 2023; 16:384. [PMID: 37880680 PMCID: PMC10601327 DOI: 10.1186/s13071-023-05959-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 09/01/2023] [Indexed: 10/27/2023] Open
Abstract
BACKGROUND The ticks Ixodes ricinus and Dermacentor reticulatus are two of the most important vectors in Europe. Climate niche modelling has been used in many studies to attempt to explain their distribution and to predict changes under a range of climate change scenarios. The aim of this study was to assess the ability of different climate niche modelling approaches to explain the known distribution of I. ricinus and D. reticulatus in Europe. METHODS A series of climate niche models, using different combinations of input data, were constructed and assessed. Species occurrence records obtained from systematic literature searches and Global Biodiversity Information Facility data were thinned to different degrees to remove sampling spatial bias. Four sources of climate data were used: bioclimatic variables, WorldClim, TerraClimate and MODIS satellite-derived data. Eight different model training extents were examined and three modelling frameworks were used: maximum entropy, generalised additive models and random forest models. The results were validated through internal cross-validation, comparison with an external independent dataset and expert opinion. RESULTS The performance metrics and predictive ability of the different modelling approaches varied significantly within and between each species. Different combinations were better able to define the distribution of each of the two species. However, no single approach was considered fully able to capture the known distribution of the species. When considering the mean of the performance metrics of internal and external validation, 24 models for I. ricinus and 11 models for D. reticulatus of the 96 constructed were considered adequate according to the following criteria: area under the receiver-operating characteristic curve > 0.7; true skill statistic > 0.4; Miller's calibration slope 0.25 above or below 1; Boyce index > 0.9; omission rate < 0.15. CONCLUSIONS This comprehensive analysis suggests that there is no single 'best practice' climate modelling approach to account for the distribution of these tick species. This has important implications for attempts to predict climate-mediated impacts on future tick distribution. It is suggested here that climate variables alone are not sufficient; habitat type, host availability and anthropogenic impacts, not included in current modelling approaches, could contribute to determining tick presence or absence at the local or regional scale.
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Affiliation(s)
- Madeleine Noll
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK.
| | - Richard Wall
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Benjamin L Makepeace
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | | | - Lukasz Adaszek
- Department of Epizootiology and Clinic of Infectious Diseases, Faculty of Veterinary Medicine, University of Life Sciences, Lublin, Poland
| | - René Bødker
- Section of Animal Welfare and Disease Control, Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Agustín Estrada-Peña
- Department of Animal Health, Faculty of Veterinary Medicine, University of Zaragoza, Saragossa, Spain
- Instituto Agroalimentario de Aragón (IA2), Saragossa, Spain
| | - Jacques Guillot
- Department of Dermatology-Parasitology-Mycology, École Nationale Vétérinaire, Oniris, Nantes, France
| | - Isabel Pereira da Fonseca
- CIISA-Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), Vila Real, Portugal
| | - Julia Probst
- Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Paul Overgaauw
- Department Population Health Sciences, Division of Veterinary Public Health, Faculty of Veterinary Medicine, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands
| | - Christina Strube
- Institute for Parasitology, Centre for Infection Medicine, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Fathiah Zakham
- Department of Virology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Stefania Zanet
- Department of Veterinary Sciences, University of Turin, Grugliasco, Italy
| | - Hannah Rose Vineer
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
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Chaisiri K, Linsuwanon P, Makepeace BL. The chigger microbiome: big questions in a tiny world. Trends Parasitol 2023; 39:696-707. [PMID: 37270375 DOI: 10.1016/j.pt.2023.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 05/06/2023] [Accepted: 05/09/2023] [Indexed: 06/05/2023]
Abstract
'Chiggers' (trombiculid mite larvae) are best known as vectors of rickettsial pathogens, Orientia spp., which cause a zoonosis, scrub typhus. However, several other pathogens (e.g., Hantaan orthohantavirus, Dabie bandavirus, Anaplasma spp., Bartonella spp., Borrelia spp., and Rickettsia spp.) and bacterial symbionts (e.g., Cardinium, Rickettsiella, and Wolbachia) are being reported from chiggers with increasing frequency. Here, we explore the surprisingly diverse chigger microbiota and potential interactions within this microcosm. Key conclusions include a possible role for chiggers as vectors of viral diseases; the dominance in some chigger populations of unidentified symbionts in several bacterial families; and increasing evidence for vertical transmission of potential pathogens and symbiotic bacteria in chiggers, suggesting intimate interactions and not simply incidental acquisition of bacteria from the environment or host.
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Affiliation(s)
- Kittipong Chaisiri
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Ratchathewi, Bangkok 10400, Thailand
| | - Piyada Linsuwanon
- Department of Entomology, US Army Medical Component, Armed Forces Research Institute of Medical Sciences, Ratchathewi, Bangkok 10400, Thailand
| | - Benjamin L Makepeace
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK.
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Ryan NM, Hess JA, Robertson EJ, Tricoche N, Turner C, Davis J, Petrovsky N, Ferguson M, Rinaldi WJ, Wong VM, Shimada A, Zhan B, Bottazzi ME, Makepeace BL, Gray SA, Carter D, Lustigman S, Abraham D. Adjuvanted Fusion Protein Vaccine Induces Durable Immunity to Onchocerca volvulus in Mice and Non-Human Primates. Vaccines (Basel) 2023; 11:1212. [PMID: 37515028 PMCID: PMC10385774 DOI: 10.3390/vaccines11071212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 06/23/2023] [Accepted: 06/27/2023] [Indexed: 07/30/2023] Open
Abstract
Onchocerciasis remains a debilitating neglected tropical disease. Due to the many challenges of current control methods, an effective vaccine against the causative agent Onchocerca volvulus is urgently needed. Mice and cynomolgus macaque non-human primates (NHPs) were immunized with a vaccine consisting of a fusion of two O. volvulus protein antigens, Ov-103 and Ov-RAL-2 (Ov-FUS-1), and three different adjuvants: Advax-CpG, alum, and AlT4. All vaccine formulations induced high antigen-specific IgG titers in both mice and NHPs. Challenging mice with O. volvulus L3 contained within subcutaneous diffusion chambers demonstrated that Ov-FUS-1/Advax-CpG-immunized animals developed protective immunity, durable for at least 11 weeks. Passive transfer of sera, collected at several time points, from both mice and NHPs immunized with Ov-FUS-1/Advax-CpG transferred protection to naïve mice. These results demonstrate that Ov-FUS-1 with the adjuvant Advax-CpG induces durable protective immunity against O. volvulus in mice and NHPs that is mediated by vaccine-induced humoral factors.
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Affiliation(s)
- Nathan M Ryan
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Jessica A Hess
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Erica J Robertson
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Nancy Tricoche
- Laboratory of Molecular Parasitology, Lindsey F. Kimball Research Institute, New York Blood Center, New York, NY 10065, USA
| | | | - Jenn Davis
- PAI Life Sciences Inc., Seattle, WA 98102, USA
| | | | | | | | | | - Ayako Shimada
- Division of Biostatistics, Department of Pharmacology and Experimental Therapeutics, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Bin Zhan
- Texas Children's Hospital Center for Vaccine Development, Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Maria Elena Bottazzi
- Texas Children's Hospital Center for Vaccine Development, Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Benjamin L Makepeace
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK
| | - Sean A Gray
- PAI Life Sciences Inc., Seattle, WA 98102, USA
| | | | - Sara Lustigman
- Laboratory of Molecular Parasitology, Lindsey F. Kimball Research Institute, New York Blood Center, New York, NY 10065, USA
| | - David Abraham
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
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Beliavskaia A, Tan KK, Sinha A, Husin NA, Lim FS, Loong SK, Bell-Sakyi L, Carlow CKS, AbuBakar S, Darby AC, Makepeace BL, Khoo JJ. Metagenomics of culture isolates and insect tissue illuminate the evolution of Wolbachia, Rickettsia and Bartonella symbionts in Ctenocephalides spp. fleas. Microb Genom 2023; 9:mgen001045. [PMID: 37399133 PMCID: PMC10438800 DOI: 10.1099/mgen.0.001045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 05/16/2023] [Indexed: 07/05/2023] Open
Abstract
While fleas are often perceived simply as a biting nuisance and a cause of allergic dermatitis, they represent important disease vectors worldwide, especially for bacterial zoonoses such as plague (transmitted by rodent fleas) and some of the rickettsioses and bartonelloses. The cosmopolitan cat (Ctenocephalides felis ) and dog (Ctenocephalides canis ) fleas, as well as Ctenocephalides orientis (restricted to tropical and subtropical Asia), breed in human dwellings and are vectors of cat-scratch fever (caused by Bartonella spp.) and Rickettsia spp., including Rickettsia felis (agent of flea-borne spotted fever) and Rickettsia asembonensis , a suspected pathogen. These Rickettsia spp. are members of a phylogenetic clade known as the ‘transitional group’, which includes both human pathogens and arthropod-specific endosymbionts. The relatively depauperate flea microbiome can also contain other endosymbionts, including a diverse range of Wolbachia strains. Here, we present circularized genome assemblies for two C. orientis -derived pathogens (Bartonella clarridgeiae and R. asembonensis ) from Malaysia, a novel Wolbachia strain (w Cori), and the C. orientis mitochondrion; all were obtained by direct metagenomic sequencing of flea tissues. Moreover, we isolated two Wolbachia strains from Malaysian C. felis into tick cell culture and recovered circularized genome assemblies for both, one of which (w CfeF) is newly sequenced. We demonstrate that the three Wolbachia strains are representatives of different major clades (‘supergroups’), two of which appear to be flea-specific. These Wolbachia genomes exhibit unique combinations of features associated with reproductive parasitism or mutualism, including prophage WO, cytoplasmic incompatibility factors and the biotin operon of obligate intracellular microbes. The first circularized assembly for R. asembonensis includes a plasmid with a markedly different structure and gene content compared to the published plasmid; moreover, this novel plasmid was also detected in cat flea metagenomes from the USA. Analysis of loci under positive selection in the transitional group revealed genes involved in host–pathogen interactions that may facilitate host switching. Finally, the first B. clarridgeiae genome from Asia exhibited large-scale genome stability compared to isolates from other continents, except for SNPs in regions predicted to mediate interactions with the vertebrate host. These findings highlight the paucity of data on the genomic diversity of Ctenocephalides -associated bacteria and raise questions regarding how interactions between members of the flea microbiome might influence vector competence.
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Affiliation(s)
- Alexandra Beliavskaia
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK
| | - Kim-Kee Tan
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Amit Sinha
- New England Biolabs, Ipswich, Massachusetts, 01938, USA
| | - Nurul Aini Husin
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Fang Shiang Lim
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Shih Keng Loong
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Lesley Bell-Sakyi
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK
| | | | - Sazaly AbuBakar
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Alistair C. Darby
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK
| | - Benjamin L. Makepeace
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK
| | - Jing Jing Khoo
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK
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8
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Noll M, Wall R, Makepeace BL, Vineer HR. Distribution of ticks in the Western Palearctic: an updated systematic review (2015-2021). Parasit Vectors 2023; 16:141. [PMID: 37095583 PMCID: PMC10127368 DOI: 10.1186/s13071-023-05773-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 04/12/2023] [Indexed: 04/26/2023] Open
Abstract
BACKGROUND The distributions of ticks and tick-borne pathogens are thought to have changed rapidly over the last two decades, with their ranges expanding into new regions. This expansion has been driven by a range of environmental and socio-economic factors, including climate change. Spatial modelling is being increasingly used to track the current and future distributions of ticks and tick-borne pathogens and to assess the associated disease risk. However, such analysis is dependent on high-resolution occurrence data for each species. To facilitate such analysis, in this review we have compiled georeferenced tick locations in the Western Palearctic, with a resolution accuracy under 10 km, that were reported between 2015 and 2021 METHODS: The PubMed and Web of Science databases were searched for peer-reviewed papers documenting the distribution of ticks that were published between 2015 and 2021, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The papers were then screened and excluded in accordance with the PRISMA flow chart. Coordinate-referenced tick locations along with information on identification and collection methods were extracted from each eligible publication. Spatial analysis was conducted using R software (version 4.1.2). RESULTS From the 1491 papers identified during the initial search, 124 met the inclusion criteria, and from these, 2267 coordinate-referenced tick records from 33 tick species were included in the final dataset. Over 30% of articles did not record the tick location adequately to meet inclusion criteria, only providing a location name or general location. Among the tick records, Ixodes ricinus had the highest representation (55%), followed by Dermacentor reticulatus (22.1%) and Ixodes frontalis (4.8%). The majority of ticks were collected from vegetation, with only 19.1% collected from hosts. CONCLUSIONS The data presented provides a collection of recent high-resolution, coordinate-referenced tick locations for use in spatial analyses, which in turn can be used in combination with previously collated datasets to analyse the changes in tick distribution and research in the Western Palearctic. In the future it is recommended that, where data privacy rules allow, high-resolution methods are routinely used by researchers to geolocate tick samples and ensure their work can be used to its full potential.
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Affiliation(s)
- Madeleine Noll
- Institute of Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK.
| | - Richard Wall
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Benjamin L Makepeace
- Institute of Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Hannah Rose Vineer
- Institute of Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
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9
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Alkathiry HA, Alghamdi SQ, Morgan HEJ, Noll ME, Khoo JJ, Alagaili AN, Makepeace BL. Molecular Detection of Candidatus Orientia chuto in Wildlife, Saudi Arabia. Emerg Infect Dis 2023; 29:402-406. [PMID: 36692446 PMCID: PMC9881777 DOI: 10.3201/eid2902.221131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Scrub typhus is a zoonosis caused by 3 species of Orientia bacteria, including Candidatus Orientia chuto. This species is known only from a human case in Dubai and infections in wildlife in Kenya. We report molecular detection of Candidatus O. chuto in 2 wild rodent species from Saudi Arabia.
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10
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Mohd-Azami SNI, Loong SK, Khoo JJ, Husin NA, Lim FS, Mahfodz NH, Ishak SN, Mohd-Taib FS, Makepeace BL, AbuBakar S. Molecular Surveillance for Vector-Borne Bacteria in Rodents and Tree Shrews of Peninsular Malaysia Oil Palm Plantations. Trop Med Infect Dis 2023; 8:tropicalmed8020074. [PMID: 36828490 PMCID: PMC9965954 DOI: 10.3390/tropicalmed8020074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 01/16/2023] [Accepted: 01/16/2023] [Indexed: 01/20/2023] Open
Abstract
Many human clinical cases attributed to vector-borne pathogens are underreported in Malaysia, especially in rural localities where healthcare infrastructures are lacking. Here, 217 small mammals, consisting of rodents and tree shrews, were trapped in oil palm plantations in the Peninsular Malaysia states of Johor and Perak. Species identification was performed using morphological and DNA barcoding analyses, and 203 small mammals were included in the detection of selected vector-borne bacteria. The DNA extracted from the spleens was examined for Orientia tsutsugamushi, Borrelia spp., Bartonella spp. and Rickettsia spp. using established PCR assays. The small mammals collected in this study included Rattus tanezumi R3 mitotype (n = 113), Rattus argentiventer (n = 24), Rattus tiomanicus (n = 22), Rattus exulans (n = 17), Rattus tanezumi sensu stricto (n = 1) and Tupaia glis (n = 40). Orientia tsutsugamushi, Borrelia spp. and Bartonella phoceensis were detected in the small mammals with the respective detection rates of 12.3%, 5.9% and 4.9%. Rickettsia spp., however, was not detected. This study encountered the presence of both Lyme disease and relapsing fever-related borreliae in small mammals collected from the oil palm plantation study sites. All three microorganisms (Orientia tsutsugamushi, Borrelia spp. and Bartonella phoceensis) were detected in the R. tanezumi R3 mitotype, suggesting that the species is a competent host for multiple microorganisms. Further investigations are warranted to elucidate the relationships between the ectoparasites, the small mammals and the respective pathogens.
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Affiliation(s)
- Siti Nurul Izzah Mohd-Azami
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Higher Institution Centre of Excellence, Universiti Malaya, Kuala Lumpur 50603, Malaysia
- Institute for Advanced Studies (IAS), Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Shih Keng Loong
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Higher Institution Centre of Excellence, Universiti Malaya, Kuala Lumpur 50603, Malaysia
- Correspondence:
| | - Jing Jing Khoo
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK
| | - Nurul Aini Husin
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Higher Institution Centre of Excellence, Universiti Malaya, Kuala Lumpur 50603, Malaysia
- Institute for Advanced Studies (IAS), Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Fang Shiang Lim
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Higher Institution Centre of Excellence, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Nur Hidayana Mahfodz
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Higher Institution Centre of Excellence, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Siti Nabilah Ishak
- Department of Biological Sciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia
- Kuantan Fisheries Biosecurity Centre, Department of Fisheries Malaysia, Kuantan 25100, Malaysia
| | - Farah Shafawati Mohd-Taib
- Department of Biological Sciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia
| | - Benjamin L. Makepeace
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK
| | - Sazaly AbuBakar
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Higher Institution Centre of Excellence, Universiti Malaya, Kuala Lumpur 50603, Malaysia
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11
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Bell-Sakyi L, Hartley CS, Khoo JJ, Forth JH, Palomar AM, Makepeace BL. New Cell Lines Derived from European Tick Species. Microorganisms 2022; 10:microorganisms10061086. [PMID: 35744603 PMCID: PMC9228755 DOI: 10.3390/microorganisms10061086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 05/20/2022] [Accepted: 05/23/2022] [Indexed: 11/16/2022] Open
Abstract
Tick cell lines are important tools for research on ticks and the pathogens they transmit. Here, we report the establishment of ten new cell lines from European ticks of the genera Argas, Dermacentor, Hyalomma, Ixodes and Rhipicephalus originating from Germany and Spain. For each cell line, the method used to generate the primary culture, a morphological description of the cells and species confirmation by sequencing of the partial 16S rRNA gene are presented. Further molecular analysis of the two new Ixodes ricinus cell lines and three existing cell lines of the same species revealed genetic variation between cell lines derived from ticks collected in the same or nearby locations. Collectively, these new cell lines will support research into a wide range of viral, bacterial and protozoal tick-borne diseases prevalent in Europe.
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Affiliation(s)
- Lesley Bell-Sakyi
- Department of Infection Biology and Microbiomes, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, 146 Brownlow Hill, Liverpool L3 5RF, UK; (C.S.H.); (J.J.K.); (B.L.M.)
- Correspondence:
| | - Catherine S. Hartley
- Department of Infection Biology and Microbiomes, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, 146 Brownlow Hill, Liverpool L3 5RF, UK; (C.S.H.); (J.J.K.); (B.L.M.)
| | - Jing Jing Khoo
- Department of Infection Biology and Microbiomes, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, 146 Brownlow Hill, Liverpool L3 5RF, UK; (C.S.H.); (J.J.K.); (B.L.M.)
| | - Jan Hendrik Forth
- Robert Koch-Institut, Nordufer 20, 13353 Berlin, Germany;
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Südufer 10, 17493 Greifswald-Insel Riems, Germany
| | - Ana M. Palomar
- Centre of Rickettsiosis and Arthropod-Borne Diseases, Hospital Universitario San Pedro-CIBIR, 26006 Logroño, La Rioja, Spain;
| | - Benjamin L. Makepeace
- Department of Infection Biology and Microbiomes, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, 146 Brownlow Hill, Liverpool L3 5RF, UK; (C.S.H.); (J.J.K.); (B.L.M.)
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12
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McGarry JW, Carrozza R, Bradley C, Latrofa MS, Makepeace BL, Otranto D. Onchocerca lupi in imported dogs in the UK: implications for animal and public health. BMC Vet Res 2022; 18:66. [PMID: 35144598 PMCID: PMC8830170 DOI: 10.1186/s12917-022-03169-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 02/03/2022] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Onchocerca lupi is a filarial nematode affecting dogs, and occasionally cats and humans, in continental Europe, North Africa, the Middle East, and the USA. Adult worms are usually found in periocular nodules and enucleation is sometimes required if the infection fails to respond to other treatment options. CASE PRESENTATION Here, we report the presence of O. lupi in the UK for the first time. Of two dogs re-homed from continental Europe, one developed an ocular nodule seven years after arrival from Portugal. The conjunctival perilimbal mass in its left eye was surgically removed but despite anthelminthic treatment, a further nodule developed in the same eye six months later. In the second case - a dog imported from Romania 12 months earlier - a perilimbal mass was excised from the left eye and prior anthelminthic treatment was supplemented with oral prednisolone and doxycycline. However, nodules recurred, and the left globe was subsequently enucleated. Conjunctival hyperaemia then appeared in the right eye and neither additional anthelminthic treatment nor removal of worm masses failed to prevent the further development of lesions. Excised adult worms were identified in both cases as O. lupi based on morphological characteristics, as well as PCR and sequencing of cytochrome c oxidase subunit I and 12S rRNA gene fragments. CONCLUSION O. lupi parasitosis can apparently remain cryptic in dogs for several years before any clinical signs manifest. Moreover, the progression of infection can be highly aggressive and recalcitrant to both surgical intervention and anthelminthic treatment. Increasingly, former stray dogs of unknown infection status are entering the UK, raising both veterinary and public health concerns.
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Affiliation(s)
- John W McGarry
- Institute of Infection, Veterinary, and Ecological Sciences, University of Liverpool, Liverpool, UK
| | | | | | - Maria S Latrofa
- Department of Veterinary Medicine, University of Bari, Valenzano, Italy
| | - Benjamin L Makepeace
- Institute of Infection, Veterinary, and Ecological Sciences, University of Liverpool, Liverpool, UK.
| | - Domenico Otranto
- Department of Veterinary Medicine, University of Bari, Valenzano, Italy.,Faculty of Veterinary Sciences, Bu-Ali Sina University, Hamedan, Iran
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13
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Buysse M, Floriano AM, Gottlieb Y, Nardi T, Comandatore F, Olivieri E, Giannetto A, Palomar AM, Makepeace BL, Bazzocchi C, Cafiso A, Sassera D, Duron O. A dual endosymbiosis supports nutritional adaptation to hematophagy in the invasive tick Hyalomma marginatum. eLife 2021; 10:e72747. [PMID: 34951405 PMCID: PMC8709577 DOI: 10.7554/elife.72747] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 12/14/2021] [Indexed: 12/25/2022] Open
Abstract
Many animals are dependent on microbial partners that provide essential nutrients lacking from their diet. Ticks, whose diet consists exclusively on vertebrate blood, rely on maternally inherited bacterial symbionts to supply B vitamins. While previously studied tick species consistently harbor a single lineage of those nutritional symbionts, we evidence here that the invasive tick Hyalomma marginatum harbors a unique dual-partner nutritional system between an ancestral symbiont, Francisella, and a more recently acquired symbiont, Midichloria. Using metagenomics, we show that Francisella exhibits extensive genome erosion that endangers the nutritional symbiotic interactions. Its genome includes folate and riboflavin biosynthesis pathways but deprived functional biotin biosynthesis on account of massive pseudogenization. Co-symbiosis compensates this deficiency since the Midichloria genome encompasses an intact biotin operon, which was primarily acquired via lateral gene transfer from unrelated intracellular bacteria commonly infecting arthropods. Thus, in H. marginatum, a mosaic of co-evolved symbionts incorporating gene combinations of distant phylogenetic origins emerged to prevent the collapse of an ancestral nutritional symbiosis. Such dual endosymbiosis was never reported in other blood feeders but was recently documented in agricultural pests feeding on plant sap, suggesting that it may be a key mechanism for advanced adaptation of arthropods to specialized diets.
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Affiliation(s)
- Marie Buysse
- MIVEGEC (Maladies Infectieuses et Vecteurs : Ecologie, Génétique, Evolution et Contrôle), Univ. Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS) - Institut pour la Recherche et le Développement (IRD)MontpellierFrance
- Centre of Research in Ecology and Evolution of Diseases (CREES), Montpellier, FranceMontpellierFrance
| | - Anna Maria Floriano
- Department of Biology and Biotechnology “L. Spallanzani”, University of PaviaPaviaItaly
- Faculty of Science, University of South BohemiaČeské BudějoviceCzech Republic
| | - Yuval Gottlieb
- Koret School of Veterinary Medicine, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of JerusalemRehovotIsrael
| | - Tiago Nardi
- Department of Biology and Biotechnology “L. Spallanzani”, University of PaviaPaviaItaly
| | - Francesco Comandatore
- Department of Biomedical and Clinical Sciences L. Sacco and Pediatric Clinical Research Center, University of MilanMilanItaly
| | - Emanuela Olivieri
- Department of Biology and Biotechnology “L. Spallanzani”, University of PaviaPaviaItaly
| | - Alessia Giannetto
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of MessinaMessinaItaly
| | - Ana M Palomar
- Center of Rickettsiosis and Arthropod-Borne Diseases (CRETAV), San Pedro University Hospital- Center of Biomedical Research from La Rioja (CIBIR)LogroñoSpain
| | - Benjamin L Makepeace
- Institute of Infection, Veterinary & Ecological Sciences, University of LiverpoolLiverpoolUnited Kingdom
| | | | | | - Davide Sassera
- Department of Biology and Biotechnology “L. Spallanzani”, University of PaviaPaviaItaly
| | - Olivier Duron
- MIVEGEC (Maladies Infectieuses et Vecteurs : Ecologie, Génétique, Evolution et Contrôle), Univ. Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS) - Institut pour la Recherche et le Développement (IRD)MontpellierFrance
- Centre of Research in Ecology and Evolution of Diseases (CREES), Montpellier, FranceMontpellierFrance
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14
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Alghamdi SQ, Low VL, Alkathiry HA, Alagaili AN, McGarry JW, Makepeace BL. Automatic barcode gap discovery reveals diverse clades of Rhipicephalus spp. and Haemaphysalis spp. ticks from small mammals in 'Asir, Saudi Arabia. Parasit Vectors 2021; 14:541. [PMID: 34666829 PMCID: PMC8527726 DOI: 10.1186/s13071-021-05049-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 10/01/2021] [Indexed: 01/14/2023] Open
Abstract
Background The ixodid tick genera Rhipicephalus and Haemaphysalis contain several species of medical and/or veterinary importance, but their diversity in some regions of the world remains under-explored. For instance, very few modern studies have been performed on the taxonomy of these genera on the Arabian Peninsula. Methods In this study, we trapped small mammals in the 'Asir Mountains of south-western Saudi Arabia and collected tick specimens for morphological examination and molecular barcoding, targeting three mitochondrial loci: cox1, 16S rRNA and 12S rRNA. Results We obtained a total of 733 ticks (608 Haemaphysalis spp. and 125 Rhipicephalus spp.) from 75 small mammal hosts belonging to six species. All tick specimens were immature except for nine adults recovered from a hedgehog (Paraechinus aethiopicus). Morphologically, the Rhipicephalus ticks resembled R. camicasi, but the Haemaphysalis ticks showed differences in palp morphology compared with species previously described from Saudi Arabia. Phylogenetic analysis and automatic barcode gap discovery identified a novel clade of Rhipicephalus sp. representing most of the nymphs. This was most closely related to R. leporis, R. guilhoni and R. linnaei. The adult ticks and a small proportion of nymphs clustered with R. camicasi sequences from a previous study. Finally, the Haemaphysalis nymphs formed two distinct clades that were clearly separated from all reference sequences but closest to some African species. Conclusions This apparent high level of tick diversity observed in a single study site of only ~ 170 km2, on a relatively small number of hosts, highlights the potential for the discovery of new tick species on the Arabian Peninsula. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-021-05049-x.
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Affiliation(s)
- Samia Q Alghamdi
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, 146 Brownlow Hill, Liverpool, L3 5RF, UK.,College of Science, Al Baha University, Al Baha Province, Alaqiq, 65779-77388, Saudi Arabia
| | - Van Lun Low
- Tropical Infectious Diseases Research & Education Centre, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
| | - Hadil A Alkathiry
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, 146 Brownlow Hill, Liverpool, L3 5RF, UK.,Department of Biology, Imam Muhammad Ibn Saud Islamic University, Riyadh, 13318, Saudi Arabia
| | - Abdulaziz N Alagaili
- Department of Zoology, King Saud University Mammals Research Chair, King Saud University, Riyadh, 12372, Saudi Arabia
| | - John W McGarry
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, 146 Brownlow Hill, Liverpool, L3 5RF, UK
| | - Benjamin L Makepeace
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, 146 Brownlow Hill, Liverpool, L3 5RF, UK.
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15
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Abraham D, Graham-Brown J, Carter D, Gray SA, Hess JA, Makepeace BL, Lustigman S. Development of a recombinant vaccine against human onchocerciasis. Expert Rev Vaccines 2021; 20:1459-1470. [PMID: 34488533 DOI: 10.1080/14760584.2021.1977125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
INTRODUCTION Human onchocerciasis caused by the filarial nematode parasite Onchocerca volvulus remains a major cause of debilitating disease infecting millions primarily in Sub-Saharan Africa. The development of a prophylactic vaccine, along with mass drug administration, would facilitate meeting the goal of onchocerciasis elimination by 2030. AREAS COVERED Models used to study immunity to Onchocerca include natural infection of cattle with Onchocerca ochengi and O. volvulus infective third-stage larvae implanted within diffusion chambers in mice. A vaccine, comprised of two adjuvanted recombinant antigens, induced protective immunity in genetically diverse mice suggesting that it will function similarly in diverse human populations. These antigens were recognized by immune humans and also induced protective immunity against Brugia malayi. We describe the development of a fusion protein composed of the two vaccine antigens with the plan to test the vaccine in cows and non-human primates as a prelude to the initiation of phase 1 clinical trials. EXPERT OPINION The adjuvanted O. volvulus vaccine composed of two antigens Ov-103 and Ov-RAL-2 was shown to be consistently effective at inducing protective immunity using multiple immune mechanisms. The vaccine is ready for further evaluation in other animal models before moving to clinical trials in humans.
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Affiliation(s)
- David Abraham
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - John Graham-Brown
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, UK
| | | | | | - Jessica A Hess
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Benjamin L Makepeace
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Sara Lustigman
- Laboratory of Molecular Parasitology, Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY, USA
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16
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Makepeace BL, Psifidi A, Robledo D, Xia D. Editorial: Genetics Architecture and Underlying Molecular Mechanisms in Host-Pathogen Interactions. Front Genet 2021; 12:695109. [PMID: 34490034 PMCID: PMC8418152 DOI: 10.3389/fgene.2021.695109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/29/2021] [Indexed: 11/26/2022] Open
Affiliation(s)
- Benjamin L Makepeace
- Department of Infection Biology and Microbiomes, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Androniki Psifidi
- Department of Clinical Science and Services, Royal Veterinary College, University of London, London, United Kingdom
| | - Diego Robledo
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
| | - Dong Xia
- Department of Comparative Biomedical Science, Royal Veterinary College, University of London, London, United Kingdom
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17
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Krücken J, Holden-Dye L, Keiser J, Prichard RK, Townson S, Makepeace BL, Hübner MP, Hahnel SR, Scandale I, Harder A, Kulke D. Development of emodepside as a possible adulticidal treatment for human onchocerciasis-The fruit of a successful industrial-academic collaboration. PLoS Pathog 2021; 17:e1009682. [PMID: 34293063 PMCID: PMC8297762 DOI: 10.1371/journal.ppat.1009682] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Current mass drug administration (MDA) programs for the treatment of human river blindness (onchocerciasis) caused by the filarial worm Onchocerca volvulus rely on ivermectin, an anthelmintic originally developed for animal health. These treatments are primarily directed against migrating microfilariae and also suppress fecundity for several months, but fail to eliminate adult O. volvulus. Therefore, elimination programs need time frames of decades, well exceeding the life span of adult worms. The situation is worsened by decreased ivermectin efficacy after long-term therapy. To improve treatment options against onchocerciasis, a drug development candidate should ideally kill or irreversibly sterilize adult worms. Emodepside is a broad-spectrum anthelmintic used for the treatment of parasitic nematodes in cats and dogs (Profender and Procox). Our current knowledge of the pharmacology of emodepside is the result of more than 2 decades of intensive collaborative research between academia and the pharmaceutical industry. Emodepside has a novel mode of action with a broad spectrum of activity, including against extraintestinal nematode stages such as migrating larvae or macrofilariae. Therefore, emodepside is considered to be among the most promising candidates for evaluation as an adulticide treatment against onchocerciasis. Consequently, in 2014, Bayer and the Drugs for Neglected Diseases initiative (DNDi) started a collaboration to develop emodepside for the treatment of patients suffering from the disease. Macrofilaricidal activity has been demonstrated in various models, including Onchocerca ochengi in cattle, the parasite most closely related to O. volvulus. Emodepside has now successfully passed Phase I clinical trials, and a Phase II study is planned. This Bayer–DNDi partnership is an outstanding example of “One World Health,” in which experience gained in veterinary science and drug development is translated to human health and leads to improved tools to combat neglected tropical diseases (NTDs) and shorten development pathways and timelines in an otherwise neglected area. Onchocerca volvulus is the causative agent of human river blindness, and current elimination programs rely on the use of ivermectin to kill microfilariae. Since no adulticidal drug is available and adult worms have a life span of up to 15 years, elimination programs need to be sustained over several decades. Emodepside is an anthelmintic that is licensed as a dewormer for cats and dogs. Due to its ability to eliminate nematodes located in various extraintestinal host tissues, including migrating larvae and adult filarial worms, it is considered to be an excellent candidate for the treatment of onchocerciasis. Intense collaboration between academia and the pharmaceutical industry has led to a deep understanding of the novel mode of action of the drug and of its parasite target spectrum. Phase I clinical trials with emodepside have demonstrated its safety and adulticide activity against the closely related cattle parasite Onchocerca ochengi. Currently, Phase II clinical trials are planned to confirm that emodepside, developed initially to improve animal health, has also the potential to improve human health by tackling a very important neglected tropical disease (NTD).
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Affiliation(s)
- Jürgen Krücken
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Lindy Holden-Dye
- School of Biological Sciences, Institute for Life Sciences, University of Southampton, Southampton, United Kingdom
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Roger K. Prichard
- Institute of Parasitology, McGill University, Sainte Anne-de-Bellevue, Quebec, Canada
| | - Simon Townson
- The Griffin Institute, Northwick Park and St. Mark’s Hospital, Harrow, United Kingdom
| | - Benjamin L. Makepeace
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Marc P. Hübner
- Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
- German Center for Infection Research (DZIF), partner site Bonn-Cologne, Bonn, Germany
| | - Steffen R. Hahnel
- Elanco Animal Health, Research & Exploratory Development, Monheim, Germany
| | - Ivan Scandale
- Drugs for Neglected Disease initiative, Geneva, Switzerland
| | | | - Daniel Kulke
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
- * E-mail:
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18
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Luu L, Palomar AM, Farrington G, Schilling AK, Premchand-Branker S, McGarry J, Makepeace BL, Meredith A, Bell-Sakyi L. Bacterial Pathogens and Symbionts Harboured by Ixodes ricinus Ticks Parasitising Red Squirrels in the United Kingdom. Pathogens 2021; 10:pathogens10040458. [PMID: 33920445 PMCID: PMC8070177 DOI: 10.3390/pathogens10040458] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 04/04/2021] [Accepted: 04/07/2021] [Indexed: 12/26/2022] Open
Abstract
Red squirrels (Sciurus vulgaris) are native to most of Eurasia; in much of the United Kingdom, they have been supplanted by the non-native grey squirrel, and are considered an endangered species. Very little is known about the range of tick-borne pathogens to which UK red squirrels are exposed. As part of trap-and-release surveys examining prevalence of Mycobacterium spp. in red squirrel populations on two UK islands, Ixodes ricinus ticks were removed from squirrels and PCR screened for Borrelia spp., intracellular arthropod-borne bacteria and the parasitic wasp Ixodiphagus hookeri. At both sites, the most commonly encountered tick-transmitted bacterium was Borrelia burgdorferi sensu lato (overall minimum prevalence 12.7%), followed by Anaplasma phagocytophilum (overall minimum prevalence 1.6%). Single ticks infected with Spiroplasma were found at both sites, and single ticks infected with Borrelia miyamotoi or an Ehrlichia sp. at one site. Ticks harbouring Wolbachia (overall minimum prevalence 15.2%) were all positive for I. hookeri. Our study shows that UK red squirrels are potentially exposed to a variety of bacterial pathogens via feeding ticks. The effects on the health and survival of this already vulnerable wildlife species are unknown, and further studies are needed to evaluate the threat posed to red squirrels by Borrelia and other tick-borne pathogens.
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Affiliation(s)
- Lisa Luu
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK; (L.L.); (G.F.); (J.M.); (B.L.M.)
| | - Ana M. Palomar
- Centre of Rickettsiosis and Arthropod-Borne Diseases, Hospital Universitario San Pedro-CIBIR, 26006 Logroño, Spain;
| | - Gemma Farrington
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK; (L.L.); (G.F.); (J.M.); (B.L.M.)
| | - Anna-Katarina Schilling
- Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK; (A.-K.S.); (A.M.)
| | - Shonnette Premchand-Branker
- Department of Biology, University of York, Wentworth Way, York YO10 5DD, UK;
- The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK
| | - John McGarry
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK; (L.L.); (G.F.); (J.M.); (B.L.M.)
| | - Benjamin L. Makepeace
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK; (L.L.); (G.F.); (J.M.); (B.L.M.)
| | - Anna Meredith
- Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK; (A.-K.S.); (A.M.)
- Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Lesley Bell-Sakyi
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK; (L.L.); (G.F.); (J.M.); (B.L.M.)
- The Pirbright Institute, Ash Road, Pirbright, Surrey GU24 0NF, UK
- Correspondence:
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19
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Ryan NM, Hess JA, de Villena FPM, Leiby BE, Shimada A, Yu L, Yarmahmoodi A, Petrovsky N, Zhan B, Bottazzi ME, Makepeace BL, Lustigman S, Abraham D. Onchocerca volvulus bivalent subunit vaccine induces protective immunity in genetically diverse collaborative cross recombinant inbred intercross mice. NPJ Vaccines 2021; 6:17. [PMID: 33500417 PMCID: PMC7838260 DOI: 10.1038/s41541-020-00276-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 12/11/2020] [Indexed: 01/04/2023] Open
Abstract
This study tests the hypothesis that an Onchocerca volvulus vaccine, consisting of two recombinant antigens (Ov-103 and Ov-RAL-2) formulated with the combination-adjuvant Advax-2, can induce protective immunity in genetically diverse Collaborative Cross recombinant inbred intercross mice (CC-RIX). CC-RIX lines were immunized with the O. volvulus vaccine and challenged with third-stage larvae. Equal and significant reductions in parasite survival were observed in 7 of 8 CC-RIX lines. Innate protective immunity was seen in the single CC-RIX line that did not demonstrate protective adaptive immunity. Analysis of a wide array of immune factors showed that each line of mice have a unique set of immune responses to vaccination and challenge suggesting that the vaccine is polyfunctional, inducing different equally-protective sets of immune responses based on the genetic background of the immunized host. Vaccine efficacy in genetically diverse mice suggests that it will also be effective in genetically complex human populations.
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Affiliation(s)
- Nathan M Ryan
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Jessica A Hess
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | | | - Benjamin E Leiby
- Division of Biostatistics, Department of Pharmacology and Experimental Therapeutics, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Ayako Shimada
- Division of Biostatistics, Department of Pharmacology and Experimental Therapeutics, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Lei Yu
- Flow Cytometry Core Facility, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA
| | - Amir Yarmahmoodi
- Flow Cytometry Core Facility, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA
| | | | - Bin Zhan
- Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA.,Texas Children's Hospital Center for Vaccine Development, 1102 Bates St, Ste. 550, Houston, TX, USA
| | - Maria Elena Bottazzi
- Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA.,Texas Children's Hospital Center for Vaccine Development, 1102 Bates St, Ste. 550, Houston, TX, USA
| | - Benjamin L Makepeace
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, 146 Brownlow Hill, Liverpool, L3 5RF, UK
| | - Sara Lustigman
- Laboratory of Molecular Parasitology, Lindsey F. Kimball Research Institute, New York Blood Center, 310 E 67th St, New York, NY, USA
| | - David Abraham
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA.
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20
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Lefoulon E, Clark T, Guerrero R, Cañizales I, Cardenas-Callirgos JM, Junker K, Vallarino-Lhermitte N, Makepeace BL, Darby AC, Foster JM, Martin C, Slatko BE. Diminutive, degraded but dissimilar: Wolbachia genomes from filarial nematodes do not conform to a single paradigm. Microb Genom 2020; 6:mgen000487. [PMID: 33295865 PMCID: PMC8116671 DOI: 10.1099/mgen.0.000487] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 11/14/2020] [Indexed: 01/13/2023] Open
Abstract
Wolbachia are alpha-proteobacteria symbionts infecting a large range of arthropod species and two different families of nematodes. Interestingly, these endosymbionts are able to induce diverse phenotypes in their hosts: they are reproductive parasites within many arthropods, nutritional mutualists within some insects and obligate mutualists within their filarial nematode hosts. Defining Wolbachia 'species' is controversial and so they are commonly classified into 17 different phylogenetic lineages, termed supergroups, named A-F, H-Q and S. However, available genomic data remain limited and not representative of the full Wolbachia diversity; indeed, of the 24 complete genomes and 55 draft genomes of Wolbachia available to date, 84 % belong to supergroups A and B, exclusively composed of Wolbachia from arthropods. For the current study, we took advantage of a recently developed DNA-enrichment method to produce four complete genomes and two draft genomes of Wolbachia from filarial nematodes. Two complete genomes, wCtub and wDcau, are the smallest Wolbachia genomes sequenced to date (863 988 bp and 863 427 bp, respectively), as well as the first genomes representing supergroup J. These genomes confirm the validity of this supergroup, a controversial clade due to weaknesses of the multilocus sequence typing approach. We also produced the first draft Wolbachia genome from a supergroup F filarial nematode representative (wMhie), two genomes from supergroup D (wLsig and wLbra) and the complete genome of wDimm from supergroup C. Our new data confirm the paradigm of smaller Wolbachia genomes from filarial nematodes containing low levels of transposable elements and the absence of intact bacteriophage sequences, unlike many Wolbachia from arthropods, where both are more abundant. However, we observe differences among the Wolbachia genomes from filarial nematodes: no global co-evolutionary pattern, strong synteny between supergroup C and supergroup J Wolbachia, and more transposable elements observed in supergroup D Wolbachia compared to the other supergroups. Metabolic pathway analysis indicates several highly conserved pathways (haem and nucleotide biosynthesis, for example) as opposed to more variable pathways, such as vitamin B biosynthesis, which might be specific to certain host-symbiont associations. Overall, there appears to be no single Wolbachia-filarial nematode pattern of co-evolution or symbiotic relationship.
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Affiliation(s)
- Emilie Lefoulon
- Molecular Parasitology Group, New England Biolabs, Ipswich, MA, USA
- Present address: School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ, USA
| | - Travis Clark
- Molecular Parasitology Group, New England Biolabs, Ipswich, MA, USA
| | - Ricardo Guerrero
- Instituto de Zoología y Ecología Tropical, Universidad Central de Venezuela, Caracas, Venezuela
| | - Israel Cañizales
- Instituto de Zoología y Ecología Tropical, Universidad Central de Venezuela, Caracas, Venezuela
- Ediciones La Fauna KPT SL, Madrid, Spain
| | - Jorge Manuel Cardenas-Callirgos
- Neotropical Parasitology Research Network - NEOPARNET, Asociación Peruana de Helmintología e Invertebrados Afines – APHIA, Peru
| | - Kerstin Junker
- Epidemiology, Parasites and Vectors, ARC-Onderstepoort Veterinary Institute, Onderstepoort 0110, South Africa
| | - Nathaly Vallarino-Lhermitte
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR7245), Muséum National d’Histoire Naturelle, CNRS, Paris, France
| | - Benjamin L. Makepeace
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Alistair C. Darby
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Jeremy M. Foster
- Molecular Parasitology Group, New England Biolabs, Ipswich, MA, USA
| | - Coralie Martin
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR7245), Muséum National d’Histoire Naturelle, CNRS, Paris, France
| | - Barton E. Slatko
- Molecular Parasitology Group, New England Biolabs, Ipswich, MA, USA
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21
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Affiliation(s)
- Thomas Weitzel
- Laboratorio Clínico, Clínica Alemana de Santiago, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
- Instituto de Ciencias e Innovación en Medicina (ICIM), Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
| | - Benjamin L. Makepeace
- Institute of Infection & Global Health, University of Liverpool, Liverpool, United Kingdom
| | - Ivo Elliott
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Mahosot Hospital, Vientiane, Lao PDR
| | - Kittipong Chaisiri
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Allen L. Richards
- Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Paul N. Newton
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Mahosot Hospital, Vientiane, Lao PDR
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22
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Chaisiri K, Gill AC, Stekolnikov AA, Hinjoy S, McGarry JW, Darby AC, Morand S, Makepeace BL. Ecological and microbiological diversity of chigger mites, including vectors of scrub typhus, on small mammals across stratified habitats in Thailand. Anim Microbiome 2019; 1:18. [PMID: 33499969 PMCID: PMC7807494 DOI: 10.1186/s42523-019-0019-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 11/20/2019] [Indexed: 02/07/2023] Open
Abstract
Background Scrub typhus, caused by a bacterial pathogen (Orientia spp.), is a potentially life-threatening febrile illness widely distributed in the Asia-Pacific region and is emerging elsewhere. The infection is transmitted by the larval stage of trombiculid mites (“chiggers”) that often exhibit low host specificity. Here, we present an analysis of chigger ecology for 38 species sampled from 11 provinces of Thailand and microbiomes for eight widespread species. Results In total, > 16,000 individual chiggers were collected from 1574 small mammal specimens belonging to 18 species across four horizontally-stratified habitat types. Chigger species richness was positively associated with higher latitudes, dry seasonal conditions, and host maturity; but negatively associated with increased human land use. Human scrub typhus incidence was found to be positively correlated with chigger species richness. The bacterial microbiome of chiggers was highly diverse, with Sphingobium, Mycobacterium, Neisseriaceae and various Bacillales representing the most abundant taxa. Only Leptotrombidium deliense was found to be infected with Orientia and another potential pathogen, Borrelia spp., was frequently detected in pools of this species. β-diversity, but not α-diversity, was significantly different between chigger species and geographic regions, although not between habitat types. Conclusion Our study identified several key environmental and host-derived correlates of chigger species richness across Thailand, which in turn impacted on human scrub typhus incidence. Moreover, this first extensive field survey of the chigger microbiome revealed species- and province-level variation in microbial β-diversity across the country, providing a framework for future studies on interactions between pathogens and other symbionts in these understudied vectors.
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Affiliation(s)
- Kittipong Chaisiri
- Institute of Infection & Global Health, University of Liverpool, Liverpool, UK.,Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - A Christina Gill
- Institute of Infection & Global Health, University of Liverpool, Liverpool, UK.,Biomedical Services, University of Oxford, Oxford, UK
| | | | - Soawapak Hinjoy
- Department of Disease Control, Ministry of Public Health, Nonthaburi, Thailand
| | - John W McGarry
- Institute of Veterinary Science, University of Liverpool, Liverpool, UK
| | - Alistair C Darby
- Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - Serge Morand
- Faculty of Veterinary Technology, Kasetsart University, Bangkok, Thailand
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23
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Al-Khafaji AM, Armstrong SD, Varotto Boccazzi I, Gaiarsa S, Sinha A, Li Z, Sassera D, Carlow CKS, Epis S, Makepeace BL. Rickettsia buchneri, symbiont of the deer tick Ixodes scapularis, can colonise the salivary glands of its host. Ticks Tick Borne Dis 2019; 11:101299. [PMID: 31542229 DOI: 10.1016/j.ttbdis.2019.101299] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 08/02/2019] [Accepted: 09/07/2019] [Indexed: 12/25/2022]
Abstract
Vertically-transmitted bacterial symbionts are widespread in ticks and have manifold impacts on the epidemiology of tick-borne diseases. For instance, they may provide essential nutrients to ticks, affect vector competence, induce immune responses in vertebrate hosts, or even evolve to become vertebrate pathogens. The deer or blacklegged tick Ixodes scapularis harbours the symbiont Rickettsia buchneri in its ovarian tissues. Here we show by molecular, proteomic and imaging methods that R. buchneri is also capable of colonising the salivary glands of wild I. scapularis. This finding has important implications for the diagnosis of rickettsial infections and for pathogen-symbiont interactions in this notorious vector of Lyme borreliosis.
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Affiliation(s)
- Alaa M Al-Khafaji
- Institute of Infection & Global Health, University of Liverpool, Liverpool, UK; College of Veterinary Medicine, University of Al-Qadisiyah, Qadisiyyah Province, Iraq
| | - Stuart D Armstrong
- Institute of Infection & Global Health, University of Liverpool, Liverpool, UK
| | - Ilaria Varotto Boccazzi
- Department of Biosciences and Pediatric Clinical Research Center, University of Milan, Milan, Italy
| | - Stefano Gaiarsa
- Microbiology and Virology Unit, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | | | - Zhiru Li
- New England Biolabs, Ipswich, MA, USA
| | - Davide Sassera
- Department of Biology & Biotechnology, University of Pavia, Pavia, Italy
| | | | - Sara Epis
- Department of Biosciences and Pediatric Clinical Research Center, University of Milan, Milan, Italy
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24
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Dong X, Chaisiri K, Xia D, Armstrong SD, Fang Y, Donnelly MJ, Kadowaki T, McGarry JW, Darby AC, Makepeace BL. Genomes of trombidid mites reveal novel predicted allergens and laterally transferred genes associated with secondary metabolism. Gigascience 2018; 7:5160133. [PMID: 30445460 PMCID: PMC6275457 DOI: 10.1093/gigascience/giy127] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 10/18/2018] [Indexed: 12/21/2022] Open
Abstract
Background Trombidid mites have a unique life cycle in which only the larval stage is ectoparasitic. In the superfamily Trombiculoidea ("chiggers"), the larvae feed preferentially on vertebrates, including humans. Species in the genus Leptotrombidium are vectors of a potentially fatal bacterial infection, scrub typhus, that affects 1 million people annually. Moreover, chiggers can cause pruritic dermatitis (trombiculiasis) in humans and domesticated animals. In the Trombidioidea (velvet mites), the larvae feed on other arthropods and are potential biological control agents for agricultural pests. Here, we present the first trombidid mites genomes, obtained both for a chigger, Leptotrombidium deliense, and for a velvet mite, Dinothrombium tinctorium. Results Sequencing was performed using Illumina technology. A 180 Mb draft assembly for D. tinctorium was generated from two paired-end and one mate-pair library using a single adult specimen. For L. deliense, a lower-coverage draft assembly (117 Mb) was obtained using pooled, engorged larvae with a single paired-end library. Remarkably, both genomes exhibited evidence of ancient lateral gene transfer from soil-derived bacteria or fungi. The transferred genes confer functions that are rare in animals, including terpene and carotenoid synthesis. Thirty-seven allergenic protein families were predicted in the L. deliense genome, of which nine were unique. Preliminary proteomic analyses identified several of these putative allergens in larvae. Conclusions Trombidid mite genomes appear to be more dynamic than those of other acariform mites. A priority for future research is to determine the biological function of terpene synthesis in this taxon and its potential for exploitation in disease control.
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Affiliation(s)
- Xiaofeng Dong
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom.,Department of Biological Sciences, Xi'an Jiaotong-Liverpool University, Suzhou 215123, China.,School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, China.,Institute of Infection & Global Health, University of Liverpool, L3 5RF, United Kingdom
| | - Kittipong Chaisiri
- Institute of Infection & Global Health, University of Liverpool, L3 5RF, United Kingdom.,Faculty of Tropical Medicine, Mahidol University, Ratchathewi Bangkok 10400, Thailand
| | - Dong Xia
- Institute of Infection & Global Health, University of Liverpool, L3 5RF, United Kingdom.,The Royal Veterinary College, London NW1 0TU, United Kingdom
| | - Stuart D Armstrong
- Institute of Infection & Global Health, University of Liverpool, L3 5RF, United Kingdom
| | - Yongxiang Fang
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | - Martin J Donnelly
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, United Kingdom
| | - Tatsuhiko Kadowaki
- Department of Biological Sciences, Xi'an Jiaotong-Liverpool University, Suzhou 215123, China
| | - John W McGarry
- Institute of Veterinary Science, University of Liverpool, Liverpool L3 5RP, United Kingdom
| | - Alistair C Darby
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | - Benjamin L Makepeace
- Institute of Infection & Global Health, University of Liverpool, L3 5RF, United Kingdom
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25
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Al-Khafaji AM, Clegg SR, Pinder AC, Luu L, Hansford KM, Seelig F, Dinnis RE, Margos G, Medlock JM, Feil EJ, Darby AC, McGarry JW, Gilbert L, Plantard O, Sassera D, Makepeace BL. Multi-locus sequence typing of Ixodes ricinus and its symbiont Candidatus Midichloria mitochondrii across Europe reveals evidence of local co-cladogenesis in Scotland. Ticks Tick Borne Dis 2018; 10:52-62. [PMID: 30197267 DOI: 10.1016/j.ttbdis.2018.08.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Revised: 07/17/2018] [Accepted: 08/29/2018] [Indexed: 01/09/2023]
Abstract
Ticks have relatively complex microbiomes, but only a small proportion of the bacterial symbionts recorded from ticks are vertically transmitted. Moreover, co-cladogenesis between ticks and their symbionts, indicating an intimate relationship over evolutionary history driven by a mutualistic association, is the exception rather than the rule. One of the most widespread tick symbionts is Candidatus Midichloria, which has been detected in all of the major tick genera of medical and veterinary importance. In some species of Ixodes, such as the sheep tick Ixodes ricinus (infected with Candidatus Midichloria mitochondrii), the symbiont is fixed in wild adult female ticks, suggesting an obligate mutualism. However, almost no information is available on genetic variation in Candidatus M. mitochondrii or possible co-cladogenesis with its host across its geographic range. Here, we report the first survey of Candidatus M. mitochondrii in I. ricinus in Great Britain and a multi-locus sequence typing (MLST) analysis of tick and symbiont between British ticks and those collected in continental Europe. We show that while the prevalence of the symbiont in nymphs collected in England is similar to that reported from the continent, a higher prevalence in nymphs and adult males is apparent in Wales. In general, Candidatus M. mitochondrii exhibits very low levels of sequence diversity, although a consistent signal of host-symbiont coevolution was apparent in Scotland. Moreover, the tick MLST scheme revealed that Scottish specimens form a clade that is partially separated from other British ticks, with almost no contribution of continental sequence types in this north-westerly border of the tick's natural range. The low diversity of Candidatus M. mitochondrii, in contrast with previously reported high rates of polymorphism in I. ricinus mitogenomes, suggests that the symbiont may have swept across Europe recently via a horizontal, rather than vertical, transmission route.
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Affiliation(s)
- Alaa M Al-Khafaji
- Institute of Infection & Global Health, University of Liverpool, 146 Brownlow Hill, Liverpool L3 5RF, UK; College of Veterinary Medicine, University of Al-Qadisiyah, Diwaniyah 58001, Qadisiyyah Province, Iraq
| | - Simon R Clegg
- Institute of Infection & Global Health, University of Liverpool, 146 Brownlow Hill, Liverpool L3 5RF, UK; School of Life Sciences, University of Lincoln, Brayford Pool, Lincoln LN6 7TS, UK
| | - Alice C Pinder
- Institute of Veterinary Science, University of Liverpool, 401 Great Newton Street, Liverpool L3 5RP, UK
| | - Lisa Luu
- Institute of Infection & Global Health, University of Liverpool, 146 Brownlow Hill, Liverpool L3 5RF, UK
| | - Kayleigh M Hansford
- Medical Entomology and Zoonoses Ecology, Public Health England, Manor Farm Road, Porton Down, Salisbury SP4 0JG, UK
| | - Frederik Seelig
- The Milner Centre for Evolution, Department of Biology & Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Ruth E Dinnis
- The Milner Centre for Evolution, Department of Biology & Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Gabriele Margos
- The Milner Centre for Evolution, Department of Biology & Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Jolyon M Medlock
- Medical Entomology and Zoonoses Ecology, Public Health England, Manor Farm Road, Porton Down, Salisbury SP4 0JG, UK
| | - Edward J Feil
- The Milner Centre for Evolution, Department of Biology & Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Alistair C Darby
- Institute of Integrative Biology, University of Liverpool, Biosciences Building, Liverpool L69 7ZB, UK
| | - John W McGarry
- Institute of Veterinary Science, University of Liverpool, 401 Great Newton Street, Liverpool L3 5RP, UK
| | - Lucy Gilbert
- Ecological Sciences Group, The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK
| | - Olivier Plantard
- BIOEPAR, INRA, Oniris, Université Bretagne Loire, 44307, Nantes, France
| | - Davide Sassera
- Department of Biology & Biotechnology, University of Pavia, via Ferrata 9, 27100, Pavia, Italy
| | - Benjamin L Makepeace
- Institute of Infection & Global Health, University of Liverpool, 146 Brownlow Hill, Liverpool L3 5RF, UK.
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26
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Bell-Sakyi L, Darby A, Baylis M, Makepeace BL. The Tick Cell Biobank: A global resource for in vitro research on ticks, other arthropods and the pathogens they transmit. Ticks Tick Borne Dis 2018; 9:1364-1371. [PMID: 29886187 PMCID: PMC6052676 DOI: 10.1016/j.ttbdis.2018.05.015] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 05/18/2018] [Accepted: 05/30/2018] [Indexed: 12/11/2022]
Abstract
Tick cell lines are increasingly used in many fields of tick and tick-borne disease research. The Tick Cell Biobank was established in 2009 to facilitate the development and uptake of these unique and valuable resources. As well as serving as a repository for existing and new ixodid and argasid tick cell lines, the Tick Cell Biobank supplies cell lines and training in their maintenance to scientists worldwide and generates novel cultures from tick species not already represented in the collection. Now part of the Institute of Infection and Global Health at the University of Liverpool, the Tick Cell Biobank has embarked on a new phase of activity particularly targeted at research on problems caused by ticks, other arthropods and the diseases they transmit in less-developed, lower- and middle-income countries. We are carrying out genotypic and phenotypic characterisation of selected cell lines derived from tropical tick species. We continue to expand the culture collection, currently comprising 63 cell lines derived from 18 ixodid and argasid tick species and one each from the sand fly Lutzomyia longipalpis and the biting midge Culicoides sonorensis, and are actively engaging with collaborators to obtain starting material for primary cell cultures from other midge species, mites, tsetse flies and bees. Outposts of the Tick Cell Biobank will be set up in Malaysia, Kenya and Brazil to facilitate uptake and exploitation of cell lines and associated training by scientists in these and neighbouring countries. Thus the Tick Cell Biobank will continue to underpin many areas of global research into biology and control of ticks, other arthropods and vector-borne viral, bacterial and protozoan pathogens.
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Affiliation(s)
- Lesley Bell-Sakyi
- Institute of Infection and Global Health, University of Liverpool, Liverpool Science Park IC2, 146 Brownlow Hill, Liverpool L3 5RF, United Kingdom.
| | - Alistair Darby
- Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, United Kingdom.
| | - Matthew Baylis
- Institute of Infection and Global Health, University of Liverpool, Liverpool Science Park IC2, 146 Brownlow Hill, Liverpool L3 5RF, United Kingdom; NIHR Health Protection Research Institute in Emerging and Zoonotic Infections, Institute of Infection and Global Health, University of Liverpool, The Ronald Ross Building, 8 West Derby Street, Liverpool L69 7BE, United Kingdom.
| | - Benjamin L Makepeace
- Institute of Infection and Global Health, University of Liverpool, Liverpool Science Park IC2, 146 Brownlow Hill, Liverpool L3 5RF, United Kingdom.
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Kumlert R, Chaisiri K, Anantatat T, Stekolnikov AA, Morand S, Prasartvit A, Makepeace BL, Sungvornyothin S, Paris DH. Autofluorescence microscopy for paired-matched morphological and molecular identification of individual chigger mites (Acari: Trombiculidae), the vectors of scrub typhus. PLoS One 2018; 13:e0193163. [PMID: 29494599 PMCID: PMC5832206 DOI: 10.1371/journal.pone.0193163] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 02/06/2018] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Conventional gold standard characterization of chigger mites involves chemical preparation procedures (i.e. specimen clearing) for visualization of morphological features, which however contributes to destruction of the arthropod host DNA and any endosymbiont or pathogen DNA harbored within the specimen. METHODOLOGY/PRINCIPAL FINDINGS In this study, a novel work flow based on autofluorescence microscopy was developed to enable identification of trombiculid mites to the species level on the basis of morphological traits without any special preparation, while preserving the mite DNA for subsequent genotyping. A panel of 16 specifically selected fluorescence microscopy images of mite features from available identification keys served for complete chigger morphological identification to the species level, and was paired with corresponding genotype data. We evaluated and validated this method for paired chigger morphological and genotypic ID using the mitochondrial cytochrome c oxidase subunit I gene (coi) in 113 chigger specimens representing 12 species and 7 genera (Leptotrombidium, Ascoschoengastia, Gahrliepia, Walchia, Blankaartia, Schoengastia and Schoutedenichia) from the Lao People's Democratic Republic (Lao PDR) to the species level (complete characterization), and 153 chiggers from 5 genera (Leptotrombidium, Ascoschoengastia, Helenicula, Schoengastiella and Walchia) from Thailand, Cambodia and Lao PDR to the genus level. A phylogenetic tree constructed from 77 coi gene sequences (approximately 640 bp length, n = 52 new coi sequences and n = 25 downloaded from GenBank), demonstrated clear grouping of assigned morphotypes at the genus levels, although evidence of both genetic polymorphism and morphological plasticity was found. CONCLUSIONS/SIGNIFICANCE With this new methodology, we provided the largest collection of characterized coi gene sequences for trombiculid mites to date, and almost doubled the number of available characterized coi gene sequences with a single study. The ability to provide paired phenotypic-genotypic data is of central importance for future characterization of mites and dissecting the molecular epidemiology of mites transmitting diseases like scrub typhus.
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Affiliation(s)
- Rawadee Kumlert
- Faculty of Tropical Medicine, Mahidol University, Ratchathewi, Bangkok, Thailand
- Department of Disease Control, Ministry of Public Health, Nonthaburi, Bangkok, Thailand
| | - Kittipong Chaisiri
- Faculty of Tropical Medicine, Mahidol University, Ratchathewi, Bangkok, Thailand
- Department of Infection Biology, Institute of Infection & Global Health, University of Liverpool, Liverpool Science Park IC2, Liverpool, United Kingdom
| | - Tippawan Anantatat
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Alexandr A. Stekolnikov
- Zoological Institute of the Russian Academy of Sciences, Universitetskaya Embankment 1, Saint Petersburg, Russia
| | - Serge Morand
- CNRS ISEM—CIRAD ASTRE, Faculty of Veterinary Technology, Kasetsart University, Bangkok, Thailand
| | - Anchana Prasartvit
- Department of Disease Control, Ministry of Public Health, Nonthaburi, Bangkok, Thailand
| | - Benjamin L. Makepeace
- Department of Infection Biology, Institute of Infection & Global Health, University of Liverpool, Liverpool Science Park IC2, Liverpool, United Kingdom
| | | | - Daniel H. Paris
- Mahidol Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
- Nuffield Department of Medicine, Oxford University, Oxford, United Kingdom
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- Faculty of Medicine, University Basel, Basel, Switzerland
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Lustigman S, Makepeace BL, Klei TR, Babayan SA, Hotez P, Abraham D, Bottazzi ME. Onchocerca volvulus: The Road from Basic Biology to a Vaccine. Trends Parasitol 2017; 34:64-79. [PMID: 28958602 DOI: 10.1016/j.pt.2017.08.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 08/27/2017] [Accepted: 08/30/2017] [Indexed: 11/18/2022]
Abstract
Human onchocerciasis - commonly known as river blindness - is one of the most devastating yet neglected tropical diseases, leaving many millions in sub-Saharan Africa blind and/or with chronic disabilities. Attempts to eliminate onchocerciasis, primarily through the mass drug administration of ivermectin, remains challenging and has been heightened by the recent news that drug-resistant parasites are developing in some populations after years of drug treatment. Needed, and needed now, in the fight to eliminate onchocerciasis are new tools, such as preventive and therapeutic vaccines. This review summarizes the progress made to advance the onchocerciasis vaccine from the research laboratory into the clinic.
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Affiliation(s)
- Sara Lustigman
- Laboratory of Molecular Parasitology, Lindsley F Kimball Research Institute, New York Blood Center, New York, NY, USA.
| | - Benjamin L Makepeace
- Department of Infection Biology, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Thomas R Klei
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA
| | - Simon A Babayan
- Institute of Biodiversity, Animal Health & Comparative Medicine, College of Medical, Veterinary & Life Sciences, University of Glasgow and Moredun Research Institute, Glasgow, UK
| | - Peter Hotez
- Texas Children's Hospital Center for Vaccine Development, Department of Pediatrics, Section of Pediatric Tropical Medicine, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA
| | - David Abraham
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Maria Elena Bottazzi
- Texas Children's Hospital Center for Vaccine Development, Department of Pediatrics, Section of Pediatric Tropical Medicine, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA
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Wewer V, Makepeace BL, Tanya VN, Peisker H, Pfarr K, Hoerauf A, Dörmann P. Lipid profiling of the filarial nematodes Onchocerca volvulus, Onchocerca ochengi and Litomosoides sigmodontis reveals the accumulation of nematode-specific ether phospholipids in the host. Int J Parasitol 2017; 47:903-912. [PMID: 28743489 PMCID: PMC5716430 DOI: 10.1016/j.ijpara.2017.06.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 06/20/2017] [Accepted: 06/21/2017] [Indexed: 01/21/2023]
Abstract
Onchocerciasis is an infectious disease caused by filarial nematodes. Three different filarial nematodes infecting cattle, humans and jirds were studied. Phospholipids in nematodes and hosts were determined by mass spectrometry. Filaria-specific ether phosphatidylethanolamine (PE) lipids accumulate in the host. These ether PE lipids could serve as potential biomarkers for onchocerciasis.
Onchocerciasis, a neglected tropical disease prevalent in western and central Africa, is a major health problem and has been targeted for elimination. The causative agent for this disease is the human parasite Onchocerca volvulus. Onchocerca ochengi and Litomosoides sigmodontis, infectious agents of cattle and rodents, respectively, serve as model organisms to study filarial nematode infections. Biomarkers to determine infection without the use of painful skin biopsies and microscopic identification of larval worms are needed and their discovery is facilitated by an improved knowledge of parasite-specific metabolites. In addition to proteins and nucleic acids, lipids may be suitable candidates for filarial biomarkers that are currently underexplored. To fill this gap, we present the phospholipid profile of the filarial nematodes O. ochengi, O. volvulus and L. sigmodontis. Direct infusion quadrupole time-of-flight (Q-TOF) mass spectrometry was employed to analyze the composition of phospholipids and their molecular species in the three nematode species. Analysis of the phospholipid profiles of plasma or serum of uninfected and infected hosts showed that nematode-specific phospholipids were below detection limits. However, several phospholipids, in particular ether lipids of phosphatidylethanolamine (PE), were abundant in O. ochengi worms and in bovine nodule fluid, suggesting that these phospholipids might be released from O. ochengi into the host, and could serve as potential biomarkers.
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Affiliation(s)
- Vera Wewer
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Sigmund-Freud-Str. 25, 53127 Bonn, Germany
| | - Benjamin L Makepeace
- Institute of Infection and Global Health, University of Liverpool, Liverpool L3 5RF, UK
| | - Vincent N Tanya
- Institut de Recherche Agricole pour le Développement, Regional Centre of Wakwa, BP65 Ngaoundéré, Cameroon
| | - Helga Peisker
- Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, Karlrobert-Kreiten-Str. 13, 53115 Bonn, Germany
| | - Kenneth Pfarr
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Sigmund-Freud-Str. 25, 53127 Bonn, Germany; German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany..
| | - Achim Hoerauf
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Sigmund-Freud-Str. 25, 53127 Bonn, Germany; German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, Bonn, Germany..
| | - Peter Dörmann
- Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, Karlrobert-Kreiten-Str. 13, 53115 Bonn, Germany.
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Dong X, Armstrong SD, Xia D, Makepeace BL, Darby AC, Kadowaki T. Draft genome of the honey bee ectoparasitic mite, Tropilaelaps mercedesae, is shaped by the parasitic life history. Gigascience 2017; 6:1-17. [PMID: 28327890 PMCID: PMC5467014 DOI: 10.1093/gigascience/gix008] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 01/01/2017] [Indexed: 01/09/2023] Open
Abstract
The number of managed honey bee colonies has considerably decreased in many developed countries in recent years and ectoparasitic mites are considered as major threats to honey bee colonies and health. However, their general biology remains poorly understood. We sequenced the genome of Tropilaelaps mercedesae, the prevalent ectoparasitic mite infesting honey bees in Asia, and predicted 15 190 protein-coding genes that were well supported by the mite transcriptomes and proteomic data. Although amino acid substitutions have been accelerated within the conserved core genes of two mites, T. mercedesae and Metaseiulus occidentalis, T. mercedesae has undergone the least gene family expansion and contraction between the seven arthropods we tested. The number of sensory system genes has been dramatically reduced, but T. mercedesae contains all gene sets required to detoxify xenobiotics. T. mercedesae is closely associated with a symbiotic bacterium (Rickettsiella grylli-like) and Deformed Wing Virus, the most prevalent honey bee virus. T. mercedesae has a very specialized life history and habitat as the ectoparasitic mite strictly depends on the honey bee inside a stable colony. Thus, comparison of the genome and transcriptome sequences with those of a tick and free-living mites has revealed the specific features of the genome shaped by interaction with the honey bee and colony environment. Genome and transcriptome sequences of T. mercedesae, as well as Varroa destructor (another globally prevalent ectoparasitic mite of honey bee), not only provide insights into the mite biology, but may also help to develop measures to control the most serious pests of the honey bee.
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Affiliation(s)
- Xiaofeng Dong
- Department of Biological Sciences, Xi'an Jiaotong-Liverpool University, 111 Ren'ai Road, Suzhou Dushu Lake Higher Education Town, Jiangsu Province 215123, China
| | - Stuart D Armstrong
- Institute of Infection & Global Health, University of Liverpool, Liverpool L3 5RF, United Kingdom
| | - Dong Xia
- Institute of Infection & Global Health, University of Liverpool, Liverpool L3 5RF, United Kingdom
| | - Benjamin L Makepeace
- Institute of Infection & Global Health, University of Liverpool, Liverpool L3 5RF, United Kingdom
| | - Alistair C Darby
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | - Tatsuhiko Kadowaki
- Department of Biological Sciences, Xi'an Jiaotong-Liverpool University, 111 Ren'ai Road, Suzhou Dushu Lake Higher Education Town, Jiangsu Province 215123, China
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31
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Lefoulon E, Giannelli A, Makepeace BL, Mutafchiev Y, Townson S, Uni S, Verocai GG, Otranto D, Martin C. Whence river blindness? The domestication of mammals and host-parasite co-evolution in the nematode genus Onchocerca. Int J Parasitol 2017; 47:457-470. [PMID: 28344097 DOI: 10.1016/j.ijpara.2016.12.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 12/19/2016] [Accepted: 12/22/2016] [Indexed: 11/25/2022]
Abstract
The genus Onchocerca includes 34 described species and represents one of the largest genera of the filarial nematodes within the family Onchocercidae. Representative members of this genus are mainly parasites of ungulates, with some exceptions such as Onchocerca lupi and Onchocerca volvulus, infecting carnivores and/or humans. For a long time, the evolutionary relationships amongst onchocercids remained poorly studied, as the systematics of this genus was impaired by the high morphological variability of species included in the taxon. Although some molecular phylogenies were developed, these studies were mainly focused on bovine Onchocerca spp. and O. volvulus, including assessments of Wolbachia endosymbionts. In the present study, we analysed 13 Onchocerca spp. from a larger host spectrum using a panel of seven different genes. Analysis of the coxI marker supports its usefulness for the identification of species within the genus. The evolutionary history of the genus has been herein revised by multi-gene phylogenies, presenting three strongly supported clades of Onchocerca spp. Analyses of co-evolutionary scenarios between Onchocerca and their vertebrate hosts underline the effect of domestication on Onchocerca speciation. Our study indicates that a host switch event occurred between Bovidae, Canidae and humans. Cophylogenetic analyses between Onchocerca and the endosymbiotic bacterium Wolbachia indicate the strongest co-evolutionary pattern ever registered within the filarial nematodes. Finally, this dataset indicates that the clade composed by O. lupi, Onchocerca gutturosa, Onchocerca lienalis, Onchocerca ochengi and O. volvulus derived from recent speciation.
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Affiliation(s)
- Emilie Lefoulon
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Universités, Muséum National d'Histoire Naturelle, CNRS, Paris, France
| | - Alessio Giannelli
- Department of Veterinary Medicine, Università degli Studi di Bari, Valenzano, Italy
| | - Benjamin L Makepeace
- Institute of Infection and Global Health, The University of Liverpool, Liverpool, United Kingdom
| | - Yasen Mutafchiev
- Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Simon Townson
- Tropical Parasitic Diseases Unit, Northwick Park Institute for Medical Research, Harrow, Middlesex, United Kingdom
| | - Shigehiko Uni
- Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
| | - Guilherme G Verocai
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Domenico Otranto
- Department of Veterinary Medicine, Università degli Studi di Bari, Valenzano, Italy
| | - Coralie Martin
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM, UMR 7245), Sorbonne Universités, Muséum National d'Histoire Naturelle, CNRS, Paris, France.
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Comandatore F, Cordaux R, Bandi C, Blaxter M, Darby A, Makepeace BL, Montagna M, Sassera D. Supergroup C Wolbachia, mutualist symbionts of filarial nematodes, have a distinct genome structure. Open Biol 2016; 5:150099. [PMID: 26631376 PMCID: PMC4703054 DOI: 10.1098/rsob.150099] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Wolbachia pipientis is possibly the most widespread endosymbiont of arthropods and nematodes. While all Wolbachia strains have historically been defined as a single species, 16 monophyletic clusters of diversity (called supergroups) have been described. Different supergroups have distinct host ranges and symbiotic relationships, ranging from mutualism to reproductive manipulation. In filarial nematodes, which include parasites responsible for major diseases of humans (such as Onchocerca volvulus, agent of river blindness) and companion animals (Dirofilaria immitis, the dog heartworm), Wolbachia has an obligate mutualist role and is the target of new treatment regimens. Here, we compare the genomes of eight Wolbachia strains, spanning the diversity of the major supergroups (A–F), analysing synteny, transposable element content, GC skew and gene loss or gain. We detected genomic features that differ between Wolbachia supergroups, most notably in the C and D clades from filarial nematodes. In particular, strains from supergroup C (symbionts of O. volvulus and D. immitis) present a pattern of GC skew, conserved synteny and lack of transposable elements, unique in the Wolbachia genus. These features could be the consequence of a distinct symbiotic relationship between C Wolbachia strains and their hosts, highlighting underappreciated differences between the mutualistic supergroups found within filarial nematodes.
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Affiliation(s)
- Francesco Comandatore
- Dipartimento di Scienze Veterinarie e Sanità Pubblica (DIVET), Università degli Studi di Milano, Milano, Italy Dipartimento di Biologia e Biotecnologie, Università degli Studi di Pavia, Pavia, Italy
| | - Richard Cordaux
- Université de Poitiers, UMR CNRS 7267 Ecologie et Biologie des Interactions, Equipe Ecologie Evolution Symbiose, Poitiers, France
| | - Claudio Bandi
- Dipartimento di Scienze Veterinarie e Sanità Pubblica (DIVET), Università degli Studi di Milano, Milano, Italy
| | - Mark Blaxter
- Institute of Evolutionary Biology and Centre for Immunity, Infection and Evolution, The School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3TF, UK
| | - Alistair Darby
- Institute of Integrative Biology and the Centre for Genomic Research, University of Liverpool, Liverpool L69 7ZB, UK
| | - Benjamin L Makepeace
- Institute of Infection and Global Health, University of Liverpool, Liverpool L3 5RF, UK
| | - Matteo Montagna
- Dipartimento di Scienze Agrarie e Ambientali, Università degli Studi di Milano, Milano, Italy
| | - Davide Sassera
- Dipartimento di Biologia e Biotecnologie, Università degli Studi di Pavia, Pavia, Italy
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Armstrong SD, Xia D, Bah GS, Krishna R, Ngangyung HF, LaCourse EJ, McSorley HJ, Kengne-Ouafo JA, Chounna-Ndongmo PW, Wanji S, Enyong PA, Taylor DW, Blaxter ML, Wastling JM, Tanya VN, Makepeace BL. Stage-specific Proteomes from Onchocerca ochengi, Sister Species of the Human River Blindness Parasite, Uncover Adaptations to a Nodular Lifestyle. Mol Cell Proteomics 2016; 15:2554-75. [PMID: 27226403 PMCID: PMC4974336 DOI: 10.1074/mcp.m115.055640] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 04/30/2016] [Indexed: 12/13/2022] Open
Abstract
Despite 40 years of control efforts, onchocerciasis (river blindness) remains one of the most important neglected tropical diseases, with 17 million people affected. The etiological agent, Onchocerca volvulus, is a filarial nematode with a complex lifecycle involving several distinct stages in the definitive host and blackfly vector. The challenges of obtaining sufficient material have prevented high-throughput studies and the development of novel strategies for disease control and diagnosis. Here, we utilize the closest relative of O. volvulus, the bovine parasite Onchocerca ochengi, to compare stage-specific proteomes and host-parasite interactions within the secretome. We identified a total of 4260 unique O. ochengi proteins from adult males and females, infective larvae, intrauterine microfilariae, and fluid from intradermal nodules. In addition, 135 proteins were detected from the obligate Wolbachia symbiont. Observed protein families that were enriched in all whole body extracts relative to the complete search database included immunoglobulin-domain proteins, whereas redox and detoxification enzymes and proteins involved in intracellular transport displayed stage-specific overrepresentation. Unexpectedly, the larval stages exhibited enrichment for several mitochondrial-related protein families, including members of peptidase family M16 and proteins which mediate mitochondrial fission and fusion. Quantification of proteins across the lifecycle using the Hi-3 approach supported these qualitative analyses. In nodule fluid, we identified 94 O. ochengi secreted proteins, including homologs of transforming growth factor-β and a second member of a novel 6-ShK toxin domain family, which was originally described from a model filarial nematode (Litomosoides sigmodontis). Strikingly, the 498 bovine proteins identified in nodule fluid were strongly dominated by antimicrobial proteins, especially cathelicidins. This first high-throughput analysis of an Onchocerca spp. proteome across the lifecycle highlights its profound complexity and emphasizes the extremely close relationship between O. ochengi and O. volvulus The insights presented here provide new candidates for vaccine development, drug targeting and diagnostic biomarkers.
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Affiliation(s)
- Stuart D Armstrong
- From the ‡Institute of Infection & Global Health, University of Liverpool, Liverpool L3 5RF, UK
| | - Dong Xia
- From the ‡Institute of Infection & Global Health, University of Liverpool, Liverpool L3 5RF, UK
| | - Germanus S Bah
- §Institut de Recherche Agricole pour le Développement, Regional Centre of Wakwa, BP65 Ngaoundéré, Cameroon
| | - Ritesh Krishna
- ¶Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Henrietta F Ngangyung
- §Institut de Recherche Agricole pour le Développement, Regional Centre of Wakwa, BP65 Ngaoundéré, Cameroon
| | - E James LaCourse
- ‖Department of Parasitology, Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Henry J McSorley
- **The Queens Medical Research Institute, University of Edinburgh, Edinburgh, EH16 4JT
| | - Jonas A Kengne-Ouafo
- ‡‡Research Foundation for Tropical Diseases and Environment, PO Box 474 Buea, Cameroon
| | | | - Samuel Wanji
- ‡‡Research Foundation for Tropical Diseases and Environment, PO Box 474 Buea, Cameroon
| | - Peter A Enyong
- ‡‡Research Foundation for Tropical Diseases and Environment, PO Box 474 Buea, Cameroon; §§Tropical Medicine Research Station, Kumba, Cameroon
| | - David W Taylor
- From the ‡Institute of Infection & Global Health, University of Liverpool, Liverpool L3 5RF, UK; ¶¶Division of Pathway Medicine, University of Edinburgh, Edinburgh EH9 3JT, UK
| | - Mark L Blaxter
- ‖‖Institute of Evolutionary Biology, University of Edinburgh, Edinburgh EH9 3JT, UK
| | - Jonathan M Wastling
- From the ‡Institute of Infection & Global Health, University of Liverpool, Liverpool L3 5RF, UK; ‡‡‡The National Institute for Health Research, Health Protection Research Unit in Emerging and Zoonotic Infections, University of Liverpool, Liverpool L3 5RF, UK
| | - Vincent N Tanya
- §Institut de Recherche Agricole pour le Développement, Regional Centre of Wakwa, BP65 Ngaoundéré, Cameroon
| | - Benjamin L Makepeace
- From the ‡Institute of Infection & Global Health, University of Liverpool, Liverpool L3 5RF, UK;
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Lefoulon E, Bain O, Makepeace BL, d'Haese C, Uni S, Martin C, Gavotte L. Breakdown of coevolution between symbiotic bacteria Wolbachia and their filarial hosts. PeerJ 2016; 4:e1840. [PMID: 27069790 PMCID: PMC4824920 DOI: 10.7717/peerj.1840] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 03/02/2016] [Indexed: 11/20/2022] Open
Abstract
Wolbachia is an alpha-proteobacterial symbiont widely distributed in arthropods. Since the identification of Wolbachia in certain animal-parasitic nematodes (the Onchocercidae or filariae), the relationship between arthropod and nematode Wolbachia has attracted great interest. The obligate symbiosis in filariae, which renders infected species susceptible to antibiotic chemotherapy, was held to be distinct from the Wolbachia-arthropod relationship, typified by reproductive parasitism. While co-evolutionary signatures in Wolbachia-arthropod symbioses are generally weak, reflecting horizontal transmission events, strict co-evolution between filariae and Wolbachia has been reported previously. However, the absence of close outgroups for phylogenetic studies prevented the determination of which host group originally acquired Wolbachia. Here, we present the largest co-phylogenetic analysis of Wolbachia in filariae performed to date including: (i) a screening and an updated phylogeny of Wolbachia; (ii) a co-phylogenetic analysis; and (iii) a hypothesis on the acquisition of Wolbachia infection. First, our results show a general overestimation of Wolbachia occurrence and support the hypothesis of an ancestral absence of infection in the nematode phylum. The accuracy of supergroup J is also underlined. Second, although a global pattern of coevolution remains, the signal is derived predominantly from filarial clades associated with Wolbachia in supergroups C and J. In other filarial clades, harbouring Wolbachia supergroups D and F, horizontal acquisitions and secondary losses are common. Finally, our results suggest that supergroup C is the basal Wolbachia clade within the Ecdysozoa. This hypothesis on the origin of Wolbachia would change drastically our understanding of Wolbachia evolution.
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Affiliation(s)
- Emilie Lefoulon
- UMR7245, MCAM, Museum national d'Histoire naturelle , Paris , France
| | - Odile Bain
- UMR7245, MCAM, Museum national d'Histoire naturelle , Paris , France
| | - Benjamin L Makepeace
- Institute of Infection and Global Health, University of Liverpool , Liverpool , United Kingdom
| | - Cyrille d'Haese
- UMR7179 MECADEV, Museum national d'Histoire naturelle , Paris , France
| | - Shigehiko Uni
- Institute of Biological Sciences, University of Malaya , Kuala Lumpur , Malaysia
| | - Coralie Martin
- UMR7245, MCAM, Museum national d'Histoire naturelle , Paris , France
| | - Laurent Gavotte
- UMR5554 ISEM, Université de Montpellier II , Montpellier , France
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Chaisiri K, Stekolnikov AA, Makepeace BL, Morand S. A Revised Checklist of Chigger Mites (Acari: Trombiculidae) From Thailand, with the Description of Three New Species. J Med Entomol 2016; 53:321-342. [PMID: 26744466 DOI: 10.1093/jme/tjv244] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Chigger mites of Thailand were studied on the basis of larvae collected from 19 small mammal species (17 species of Rodentia, 1 species of Erinaceomorpha, and 1 species of Scandentia) and revision of published data. Samples of 38 trombiculid species were collected from 11 provinces. Three new species were described: Trombiculindus kosapani sp. nov., Helenicula naresuani sp. nov., and Walchia chavali sp. nov. Ten species were recorded in Thailand for the first time: Leptotrombidium sialkotense Vercammen-Grandjean and Langston, 1976; Leptotrombidium subangulare Wen and Xiang, 1984; Leptotrombidium tenompaki Stekolnikov, 2013; Leptotrombidium turdicola Vercammen-Grandjean and Langston, 1976; Leptotrombidium yunlingense Yu, Yang, Zhang and Hu, 1981; Lorillatum hekouensis Yu, Chen and Lin, 1996; Helenicula pilosa (Abonnenc and Taufflieb, 1957); Gahrliepia xiaowoi Wen and Xiang, 1984; Walchia minuscuta Chen, 1978; and Walchia ventralis (Womersley, 1952). In all, 99 chigger mite species were considered; the presence of 93 species was established in Thailand by original data or properly documented records in the scientific literature. Evidence for 64 species records of 147 from a previous checklist of Thai chiggers (Tanskul 1993) remains unknown. Distribution of chigger species by geographical regions of Thailand is discussed.
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Affiliation(s)
- Kittipong Chaisiri
- Department of Infection Biology, Institute of Infection & Global Health, University of Liverpool, Liverpool Science Park IC2, 146 Brownlow Hill, Liverpool L35RF, United Kingdom; Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchathewi, Bangkok 10400, Thailand.
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Makepeace BL, Babayan SA, Lustigman S, Taylor DW. The case for vaccine development in the strategy to eradicate river blindness (onchocerciasis) from Africa. Expert Rev Vaccines 2015; 14:1163-5. [PMID: 26091691 DOI: 10.1586/14760584.2015.1059281] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Onchocerciasis or river blindness is a neglected parasitic disease causing severe dermatitis and visual impairment, predominantly in Africa. Historically, onchocerciasis control targeted vector breeding sites, but the current strategy relies on mass administration of a single drug, ivermectin. As programmatic goals shift from reducing public health impact to active elimination, sole reliance on ivermectin is threatened by contraindications in areas coendemic for loiasis, an inability to break transmission in some foci, and the emergence of drug resistance. Here, we argue that prophylactic and therapeutic vaccines would accelerate elimination efforts and safeguard the enormous strides made in onchocerciasis control. These vaccines could be based on one or more of three lead candidates identified by a newly formed transatlantic partnership, The Onchocerciasis Vaccine for Africa Initiative.
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Affiliation(s)
- Benjamin L Makepeace
- Institute of Infection & Global Health, University of Liverpool, Liverpool Science Park IC2, 146 Brownlow Hill, Liverpool L3 5RF, UK
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Bah GS, Tanya VN, Makepeace BL. Immunotherapy with mutated onchocystatin fails to enhance the efficacy of a sub-lethal oxytetracycline regimen against Onchocerca ochengi. Vet Parasitol 2015; 212:25-34. [PMID: 26100152 DOI: 10.1016/j.vetpar.2015.06.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 05/30/2015] [Accepted: 06/06/2015] [Indexed: 11/26/2022]
Abstract
Human onchocerciasis (river blindness), caused by the filarial nematode Onchocerca volvulus, has been successfully controlled by a single drug, ivermectin, for over 25 years. Ivermectin prevents the disease symptoms of severe itching and visual impairment by killing the microfilarial stage, but does not eliminate the adult parasites, necessitating repeated annual treatments. Mass drug administration with ivermectin does not always break transmission in forest zones and is contraindicated in individuals heavily co-infected with Loa loa, while reports of reduced drug efficacy in Ghana and Cameroon may signal the development of resistance. An alternative treatment for onchocerciasis involves targeting the essential Wolbachia symbiont with tetracycline or its derivatives, which are adulticidal. However, implementation of antibiotic therapy has not occurred on a wide scale due to the prolonged treatment regimen required (several weeks). In the bovine Onchocerca ochengi system, it has been shown previously that prolonged oxytetracycline therapy increases eosinophil counts in intradermal nodules, which kill the adult worms by degranulating on their surface. Here, in an "immunochemotherapeutic" approach, we sought to enhance the efficacy of a short, sub-lethal antibiotic regimen against O. ochengi by prior immunotherapy targeting onchocystatin, an immunomodulatory protein located in the adult female worm cuticle. A key asparagine residue in onchocystatin was mutated to ablate immunomodulatory activity, which has been demonstrated previously to markedly improve the protective efficacy of this vaccine candidate when used as an immunoprophylactic. The immunochemotherapeutic regimen was compared with sub-lethal oxytetracycline therapy alone; onchocystatin immunotherapy alone; a gold-standard prolonged, intermittent oxytetracycline regimen; and no treatment (negative control) in naturally infected Cameroonian cattle. Readouts were collected over one year and comprised adult worm viability, dermal microfilarial density, anti-onchocystatin IgG in sera, and eosinophil counts in nodules. Only the gold-standard antibiotic regimen achieved significant killing of adult worms, a profound reduction in microfilarial load, and a sustained increase in local tissue eosinophilia. A small but statistically significant elevation in anti-onchocystatin IgG was observed for several weeks after immunisation in the immunotherapy-only group, but the antibody response in the immunochemotherapy group was more variable. At 12 weeks post-treatment, only a transient and non-significant increase in eosinophil counts was apparent in the immunochemotherapy group. We conclude that the addition of onchocystatin immunotherapy to a sub-lethal antibiotic regimen is insufficient to induce adulticidal activity, although with booster immunisations or the targeting of additional filarial immunomodulatory proteins, the efficacy of this strategy could be strengthened.
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Affiliation(s)
- Germanus S Bah
- Institute of Infection & Global Health, University of Liverpool, 146 Brownlow Hill, Liverpool Science Park IC2, Liverpool L3 5RF, UK; Institut de Recherche Agricole pour le Développement, Regional Centre of Wakwa, BP 65 Ngaoundéré, Adamawa Region, Cameroon
| | - Vincent N Tanya
- Institut de Recherche Agricole pour le Développement, Regional Centre of Wakwa, BP 65 Ngaoundéré, Adamawa Region, Cameroon; Cameroon Academy of Sciences, BP 1457 Yaoundé, Centre Region, Cameroon
| | - Benjamin L Makepeace
- Institute of Infection & Global Health, University of Liverpool, 146 Brownlow Hill, Liverpool Science Park IC2, Liverpool L3 5RF, UK.
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Quintana JF, Makepeace BL, Babayan SA, Ivens A, Pfarr KM, Blaxter M, Debrah A, Wanji S, Ngangyung HF, Bah GS, Tanya VN, Taylor DW, Hoerauf A, Buck AH. Extracellular Onchocerca-derived small RNAs in host nodules and blood. Parasit Vectors 2015; 8:58. [PMID: 25623184 PMCID: PMC4316651 DOI: 10.1186/s13071-015-0656-1] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 01/12/2015] [Indexed: 12/02/2022] Open
Abstract
Background microRNAs (miRNAs), a class of short, non-coding RNA can be found in a highly stable, cell-free form in mammalian body fluids. Specific miRNAs are secreted by parasitic nematodes in exosomes and have been detected in the serum of murine and dog hosts infected with the filarial nematodes Litomosoides sigmodontis and Dirofilaria immitis, respectively. Here we identify extracellular, parasite-derived small RNAs associated with Onchocerca species infecting cattle and humans. Methods Small RNA libraries were prepared from total RNA extracted from the nodule fluid of cattle infected with Onchocerca ochengi as well as serum and plasma from humans infected with Onchocerca volvulus in Cameroon and Ghana. Parasite-derived miRNAs were identified based on the criteria that sequences unambiguously map to hairpin structures in Onchocerca genomes, do not align to the human genome and are not present in European control serum. Results A total of 62 mature miRNAs from 52 distinct pre-miRNA candidates were identified in nodule fluid from cattle infected with O. ochengi of which 59 are identical in the genome of the human parasite O. volvulus. Six of the extracellular miRNAs were also identified in sequencing analyses of serum and plasma from humans infected with O. volvulus. Based on sequencing analysis the abundance levels of the parasite miRNAs in serum or plasma range from 5 to 127 reads/per million total host miRNA reads identified, comparable to our previous analyses of Schistosoma mansoni and L. sigmodontis miRNAs in serum. All six of the O. volvulus miRNAs identified have orthologs in other filarial nematodes and four were identified in the serum of mice infected with L. sigmodontis. Conclusions We have identified parasite-derived miRNAs associated with onchocerciasis in cattle and humans. Our results confirm the conserved nature of RNA secretion by diverse nematodes. Additional species-specific small RNAs from O. volvulus may be present in serum based on the novel miRNA sequences identified in the nodule fluid. In our analyses comparison to European control serum illuminates the scope for false-positives, warranting caution in criteria that should be applied to identification of biomarkers of infection. Electronic supplementary material The online version of this article (doi:10.1186/s13071-015-0656-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Juan F Quintana
- Centre for Immunity, Infection and Evolution, Ashworth Laboratories, University of Edinburgh, West Mains Road, Edinburgh, UK.
| | - Benjamin L Makepeace
- Institute of Infection and Global Health, University of Liverpool, Liverpool, Merseyside, UK.
| | - Simon A Babayan
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
| | - Alasdair Ivens
- Centre for Immunity, Infection and Evolution, Ashworth Laboratories, University of Edinburgh, West Mains Road, Edinburgh, UK.
| | - Kenneth M Pfarr
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany.
| | - Mark Blaxter
- Centre for Immunity, Infection and Evolution, Ashworth Laboratories, University of Edinburgh, West Mains Road, Edinburgh, UK.
| | - Alexander Debrah
- Kumasi Centre for Collaborative Research (KCCR) and Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
| | - Samuel Wanji
- Research Foundation in Tropical Diseases and Environment and University of Buea, Buea, Cameroon.
| | - Henrietta F Ngangyung
- Institut de Recherche Agricole pour le Développement, Regional Centre of Wakwa, Ngaoundéré, Cameroon.
| | - Germanus S Bah
- Institut de Recherche Agricole pour le Développement, Regional Centre of Wakwa, Ngaoundéré, Cameroon.
| | | | - David W Taylor
- Institute of Infection and Global Health, University of Liverpool, Liverpool, Merseyside, UK. .,Division of Pathway Medicine, School for Biomedical Sciences, University of Edinburgh, Little France, Edinburgh, UK.
| | - Achim Hoerauf
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital of Bonn, Bonn, Germany.
| | - Amy H Buck
- Centre for Immunity, Infection and Evolution, Ashworth Laboratories, University of Edinburgh, West Mains Road, Edinburgh, UK.
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Abstract
The bacterium Wolbachia (order Rickettsiales) is probably the world's most successful vertically-transmitted symbiont, distributed among a staggering 40% of terrestrial arthropod species. Wolbachia has great potential in vector control due to its ability to manipulate its hosts' reproduction and to impede the replication and dissemination of arboviruses and other pathogens within haematophagous arthropods. In addition, the unexpected presence of Wolbachia in filarial nematodes of medical and veterinary importance has provided an opportunity to target the adult worms of Wuchereria bancrofti, Onchocerca volvulus, and Dirofilaria immitis with safe drugs such as doxycycline. A striking feature of Wolbachia is its phenotypic plasticity between (and sometimes within) hosts, which may be underpinned by its ability to integrate itself into several key processes within eukaryotic cells: oxidative stress, autophagy, and apoptosis. Importantly, despite significant differences in the genomes of arthropod and filarial Wolbachia strains, these nexuses appear to lie on a continuum in different hosts. Here, we consider how iron metabolism may represent a fundamental aspect of host homeostasis that is impacted by Wolbachia infection, connecting disparate pathways ranging from the provision of haem and ATP to programmed cell death, aging, and the recycling of intracellular resources. Depending on how Wolbachia and host cells interact across networks that depend on iron, the gradient between parasitism and mutualism may shift dynamically in some systems, or alternatively, stabilise on one or the other end of the spectrum.
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Affiliation(s)
- Alessandra Christina Gill
- Institute of Infection & Global Health, University of Liverpool, Liverpool, Merseyside, United Kingdom
| | - Alistair C. Darby
- Institute of Integrative Biology and the Centre for Genomic Research, University of Liverpool, Liverpool, Merseyside, United Kingdom
| | - Benjamin L. Makepeace
- Institute of Infection & Global Health, University of Liverpool, Liverpool, Merseyside, United Kingdom
- * E-mail:
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Alhassan A, Makepeace BL, LaCourse EJ, Osei-Atweneboana MY, Carlow CKS. A simple isothermal DNA amplification method to screen black flies for Onchocerca volvulus infection. PLoS One 2014; 9:e108927. [PMID: 25299656 PMCID: PMC4191976 DOI: 10.1371/journal.pone.0108927] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 10/09/2014] [Indexed: 11/30/2022] Open
Abstract
Onchocerciasis is a debilitating neglected tropical disease caused by infection with the filarial parasite Onchocerca volvulus. Adult worms live in subcutaneous tissues and produce large numbers of microfilariae that migrate to the skin and eyes. The disease is spread by black flies of the genus Simulium following ingestion of microfilariae that develop into infective stage larvae in the insect. Currently, transmission is monitored by capture and dissection of black flies and microscopic examination of parasites, or using the polymerase chain reaction to determine the presence of parasite DNA in pools of black flies. In this study we identified a new DNA biomarker, encoding O. volvulus glutathione S-transferase 1a (OvGST1a), to detect O. volvulus infection in vector black flies. We developed an OvGST1a-based loop-mediated isothermal amplification (LAMP) assay where amplification of specific target DNA is detectable using turbidity or by a hydroxy naphthol blue color change. The results indicated that the assay is sensitive and rapid, capable of detecting DNA equivalent to less than one microfilaria within 60 minutes. The test is highly specific for the human parasite, as no cross-reaction was detected using DNA from the closely related and sympatric cattle parasite Onchocerca ochengi. The test has the potential to be developed further as a field tool for use in the surveillance of transmission before and after implementation of mass drug administration programs for onchocerciasis.
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Affiliation(s)
- Andy Alhassan
- Division of Genome Biology, New England Biolabs, Ipswich, Massachusetts, United States of America
| | - Benjamin L. Makepeace
- Institute of Infection & Global Health, University of Liverpool, Liverpool, United Kingdom
| | | | | | - Clotilde K. S. Carlow
- Division of Genome Biology, New England Biolabs, Ipswich, Massachusetts, United States of America
- * E-mail:
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Armstrong SD, Babayan SA, Lhermitte-Vallarino N, Gray N, Xia D, Martin C, Kumar S, Taylor DW, Blaxter ML, Wastling JM, Makepeace BL. Comparative analysis of the secretome from a model filarial nematode (Litomosoides sigmodontis) reveals maximal diversity in gravid female parasites. Mol Cell Proteomics 2014; 13:2527-44. [PMID: 24958169 DOI: 10.1074/mcp.m114.038539] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Filarial nematodes (superfamily Filarioidea) are responsible for an annual global health burden of ∼6.3 million disability-adjusted life-years, which represents the greatest single component of morbidity attributable to helminths affecting humans. No vaccine exists for the major filarial diseases, lymphatic filariasis and onchocerciasis; in part because research on protective immunity against filariae has been constrained by the inability of the human-parasitic species to complete their lifecycles in laboratory mice. However, the rodent filaria Litomosoides sigmodontis has become a popular experimental model, as BALB/c mice are fully permissive for its development and reproduction. Here, we provide a comprehensive analysis of excretory-secretory products from L. sigmodontis across five lifecycle stages and identifications of host proteins associated with first-stage larvae (microfilariae) in the blood. Applying intensity-based quantification, we determined the abundance of 302 unique excretory-secretory proteins, of which 64.6% were present in quantifiable amounts only from gravid adult female nematodes. This lifecycle stage, together with immature microfilariae, released four proteins that have not previously been evaluated as vaccine candidates: a predicted 28.5 kDa filaria-specific protein, a zonadhesin and SCO-spondin-like protein, a vitellogenin, and a protein containing six metridin-like ShK toxin domains. Female nematodes also released two proteins derived from the obligate Wolbachia symbiont. Notably, excretory-secretory products from all parasite stages contained several uncharacterized members of the transthyretin-like protein family. Furthermore, biotin labeling revealed that redox proteins and enzymes involved in purinergic signaling were enriched on the adult nematode cuticle. Comparison of the L. sigmodontis adult secretome with that of the human-infective filarial nematode Brugia malayi (reported previously in three independent published studies) identified differences that suggest a considerable underlying diversity of potential immunomodulators. The molecules identified in L. sigmodontis excretory-secretory products show promise not only for vaccination against filarial infections, but for the amelioration of allergy and autoimmune diseases.
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Affiliation(s)
- Stuart D Armstrong
- From the ‡Institute of Infection and Global Health, University of Liverpool, Liverpool L3 5RF, UK
| | - Simon A Babayan
- §Centre for Immunity, Infection & Evolution and Institute of Evolutionary Biology, University of Edinburgh, Edinburgh EH9 3JT, UK
| | | | - Nick Gray
- §Centre for Immunity, Infection & Evolution and Institute of Evolutionary Biology, University of Edinburgh, Edinburgh EH9 3JT, UK
| | - Dong Xia
- From the ‡Institute of Infection and Global Health, University of Liverpool, Liverpool L3 5RF, UK
| | - Coralie Martin
- ¶UMR 7245 MCAM CNRS, Muséum National d'Histoire Naturelle, 75231 Paris, France
| | - Sujai Kumar
- §Centre for Immunity, Infection & Evolution and Institute of Evolutionary Biology, University of Edinburgh, Edinburgh EH9 3JT, UK
| | - David W Taylor
- ‖Division of Pathway Medicine, University of Edinburgh, Edinburgh EH9 3JT, UK
| | - Mark L Blaxter
- §Centre for Immunity, Infection & Evolution and Institute of Evolutionary Biology, University of Edinburgh, Edinburgh EH9 3JT, UK
| | - Jonathan M Wastling
- From the ‡Institute of Infection and Global Health, University of Liverpool, Liverpool L3 5RF, UK; **The National Institute for Health Research, Health Protection Research Unit in Emerging and Zoonotic Infections, University of Liverpool, Liverpool L3 5RF, UK
| | - Benjamin L Makepeace
- From the ‡Institute of Infection and Global Health, University of Liverpool, Liverpool L3 5RF, UK;
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Darby AC, Armstrong SD, Bah GS, Kaur G, Hughes MA, Kay SM, Koldkjær P, Rainbow L, Radford AD, Blaxter ML, Tanya VN, Trees AJ, Cordaux R, Wastling JM, Makepeace BL. Analysis of gene expression from the Wolbachia genome of a filarial nematode supports both metabolic and defensive roles within the symbiosis. Genome Res 2012; 22:2467-77. [PMID: 22919073 PMCID: PMC3514676 DOI: 10.1101/gr.138420.112] [Citation(s) in RCA: 146] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 07/27/2012] [Indexed: 02/06/2023]
Abstract
The α-proteobacterium Wolbachia is probably the most prevalent, vertically transmitted symbiont on Earth. In contrast with its wide distribution in arthropods, Wolbachia is restricted to one family of animal-parasitic nematodes, the Onchocercidae. This includes filarial pathogens such as Onchocerca volvulus, the cause of human onchocerciasis, or river blindness. The symbiosis between filariae and Wolbachia is obligate, although the basis of this dependency is not fully understood. Previous studies suggested that Wolbachia may provision metabolites (e.g., haem, riboflavin, and nucleotides) and/or contribute to immune defense. Importantly, Wolbachia is restricted to somatic tissues in adult male worms, whereas females also harbor bacteria in the germline. We sought to characterize the nature of the symbiosis between Wolbachia and O. ochengi, a bovine parasite representing the closest relative of O. volvulus. First, we sequenced the complete genome of Wolbachia strain wOo, which revealed an inability to synthesize riboflavin de novo. Using RNA-seq, we also generated endobacterial transcriptomes from male soma and female germline. In the soma, transcripts for membrane transport and respiration were up-regulated, while the gonad exhibited enrichment for DNA replication and translation. The most abundant Wolbachia proteins, as determined by geLC-MS, included ligands for mammalian Toll-like receptors. Enzymes involved in nucleotide synthesis were dominant among metabolism-related proteins, whereas the haem biosynthetic pathway was poorly represented. We conclude that Wolbachia may have a mitochondrion-like function in the soma, generating ATP for its host. Moreover, the abundance of immunogenic proteins in wOo suggests a role in diverting the immune system toward an ineffective antibacterial response.
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Affiliation(s)
- Alistair C. Darby
- Institute of Integrative Biology and the Centre for Genomic Research, Biosciences Building, University of Liverpool, Liverpool, Merseyside L69 7ZB, United Kingdom
| | - Stuart D. Armstrong
- Institute of Infection & Global Health, Liverpool Science Park IC2, University of Liverpool, Liverpool, Merseyside L3 5RF, United Kingdom
| | - Germanus S. Bah
- Institute of Infection & Global Health, Liverpool Science Park IC2, University of Liverpool, Liverpool, Merseyside L3 5RF, United Kingdom
- Institut de Recherche Agricole pour le Développement, Regional Centre of Wakwa, Ngaoundéré, BP65 Adamawa Region, Cameroon
| | - Gaganjot Kaur
- Institute of Evolutionary Biology and the GenePool Genomics Facility, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JT, United Kingdom
| | - Margaret A. Hughes
- Institute of Integrative Biology and the Centre for Genomic Research, Biosciences Building, University of Liverpool, Liverpool, Merseyside L69 7ZB, United Kingdom
| | - Suzanne M. Kay
- Institute of Integrative Biology and the Centre for Genomic Research, Biosciences Building, University of Liverpool, Liverpool, Merseyside L69 7ZB, United Kingdom
| | - Pia Koldkjær
- Institute of Integrative Biology and the Centre for Genomic Research, Biosciences Building, University of Liverpool, Liverpool, Merseyside L69 7ZB, United Kingdom
| | - Lucille Rainbow
- Institute of Integrative Biology and the Centre for Genomic Research, Biosciences Building, University of Liverpool, Liverpool, Merseyside L69 7ZB, United Kingdom
| | - Alan D. Radford
- Institute of Infection & Global Health, Liverpool Science Park IC2, University of Liverpool, Liverpool, Merseyside L3 5RF, United Kingdom
| | - Mark L. Blaxter
- Institute of Evolutionary Biology and the GenePool Genomics Facility, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JT, United Kingdom
| | - Vincent N. Tanya
- Institut de Recherche Agricole pour le Développement, Regional Centre of Wakwa, Ngaoundéré, BP65 Adamawa Region, Cameroon
| | - Alexander J. Trees
- Institute of Infection & Global Health, Liverpool Science Park IC2, University of Liverpool, Liverpool, Merseyside L3 5RF, United Kingdom
| | - Richard Cordaux
- Laboratoire Ecologie et Biologie des Interactions (UMR CNRS 7267), Equipe Ecologie Evolution Symbiose, Université de Poitiers, 86022 Poitiers CEDEX, France
| | - Jonathan M. Wastling
- Institute of Infection & Global Health, Liverpool Science Park IC2, University of Liverpool, Liverpool, Merseyside L3 5RF, United Kingdom
| | - Benjamin L. Makepeace
- Institute of Infection & Global Health, Liverpool Science Park IC2, University of Liverpool, Liverpool, Merseyside L3 5RF, United Kingdom
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Makepeace BL, Martin C, Turner JD, Specht S. Granulocytes in helminth infection -- who is calling the shots? Curr Med Chem 2012; 19:1567-86. [PMID: 22360486 PMCID: PMC3394172 DOI: 10.2174/092986712799828337] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Revised: 12/23/2011] [Accepted: 12/26/2011] [Indexed: 02/06/2023]
Abstract
Helminths are parasitic organisms that can be broadly described as “worms” due to their elongated body plan, but which otherwise differ in shape, development, migratory routes and the predilection site of the adults and larvae. They are divided into three major groups: trematodes (flukes), which are leaf-shaped, hermaphroditic (except for blood flukes) flatworms with oral and ventral suckers; cestodes (tapeworms), which are segmented, hermaphroditic flatworms that inhabit the intestinal lumen; and nematodes (roundworms), which are dioecious, cylindrical parasites that inhabit intestinal and peripheral tissue sites. Helminths exhibit a sublime co-evolution with the host´s immune system that has enabled them to successfully colonize almost all multicellular species present in every geographical environment, including over two billion humans. In the face of this challenge, the host immune system has evolved to strike a delicate balance between attempts to neutralize the infectious assault versus limitation of damage to host tissues. Among the most important cell types during helminthic invasion are granulocytes: eosinophils, neutrophils and basophils. Depending on the specific context, these leukocytes may have pivotal roles in host protection, immunopathology, or facilitation of helminth establishment. This review provides an overview of the function of granulocytes in helminthic infections.
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Affiliation(s)
- B L Makepeace
- Department of Infection Biology, Institute of Infection & Global Health, University of Liverpool, Liverpool L69 7ZJ, UK
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Hansen RDE, Trees AJ, Bah GS, Hetzel U, Martin C, Bain O, Tanya VN, Makepeace BL. A worm's best friend: recruitment of neutrophils by Wolbachia confounds eosinophil degranulation against the filarial nematode Onchocerca ochengi. Proc Biol Sci 2010; 278:2293-302. [PMID: 21177682 PMCID: PMC3119012 DOI: 10.1098/rspb.2010.2367] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Onchocerca ochengi, a filarial parasite of cattle, represents the closest relative of the human pathogen, Onchocerca volvulus. Both species harbour Wolbachia endosymbionts and are remarkable in that adult female worms remain viable but sessile for many years while surrounded by host cells and antibodies. The basis of the symbiosis between filariae and Wolbachia is thought to be metabolic, although a role for Wolbachia in immune evasion has received little attention. Neutrophils are attracted to Wolbachia, but following antibiotic chemotherapy they are replaced by eosinophils that degranulate on the worm cuticle. However, it is unclear whether the eosinophils are involved in parasite killing or if they are attracted secondarily to dying worms. In this study, cattle infected with Onchocerca ochengi received adulticidal regimens of oxytetracycline or melarsomine. In contrast to oxytetracycline, melarsomine did not directly affect Wolbachia viability. Eosinophil degranulation increased significantly only in the oxytetracycline group; whereas nodular gene expression of bovine neutrophilic chemokines was lowest in this group. Moreover, intense eosinophil degranulation was initially associated with worm vitality, not degeneration. Taken together, these data offer strong support for the hypothesis that Wolbachia confers longevity on O. ochengi through a defensive mutualism, which diverts a potentially lethal effector cell response.
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Affiliation(s)
- Rowena D E Hansen
- Liverpool School of Tropical Medicine, School of Veterinary Science and Institute of Infection and Global Health, University of Liverpool, , Liverpool L69 7ZJ, UK
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Neary JM, Trees AJ, Ekale DD, Tanya VN, Hetzel U, Makepeace BL. Onchocerca armillata contains the endosymbiotic bacterium Wolbachia and elicits a limited inflammatory response. Vet Parasitol 2010; 174:267-76. [PMID: 20850932 PMCID: PMC3038270 DOI: 10.1016/j.vetpar.2010.08.031] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2010] [Revised: 08/16/2010] [Accepted: 08/23/2010] [Indexed: 11/27/2022]
Abstract
Human onchocerciasis, also known as River Blindness, is a debilitating disease caused by the filarial nematode Onchocerca volvulus. Many, but not all, filarial nematodes carry within their tissues endosymbiotic, Rickettsia-like bacteria of the genus Wolbachia. Onchocerca spp. infections in cattle offer the most relevant, analogous host–parasite model system. West African cattle are commonly co-infected with four Onchocerca spp.; two of these are Wolbachia-positive (Onchocerca gutturosa and Onchocerca ochengi), and the remainder are of unknown Wolbachia status (Onchocerca dukei and Onchocerca armillata). Previous studies have suggested that worm survival is dependent on this bacterium. O. armillata, an abundant parasite of African cattle that has received little attention, is a primitive species that may lack Wolbachia. The objectives of this study were to determine if O. armillata carries Wolbachia and to provide preliminary descriptions of the host inflammatory cell environment around the adult worms. The findings may support or refute the hypothesis that a prime contribution of Wolbachia is to permit long-term survival and reproduction of certain Onchocerca spp. (including O. volvulus in humans). O. armillata adult worms were found in the aorta of 90.7% of cattle (n = 54) slaughtered at an abattoir in Ngaoundéré, Adamawa Region, Cameroon. The presence of Wolbachia in O. armillata was confirmed by a specific anti-Wolbachia surface protein antibody detected using a peroxidase conjugate (immunohistochemistry) and PCR for detection of Wolbachia-specific sequences within DNA extracts from frozen worms. Tissue sections stained with haematoxylin and eosin showed the host cell response to be dominated by macrophages and fibroblasts. This is unusual compared with nodule-dwelling Wolbachia-positive Onchocerca spp., where the host response is typically characterised by granulocytes, and suggests that the mechanisms for worm survival employed by this species (which is probably motile) may differ.
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Affiliation(s)
- Joseph M Neary
- Liverpool School of Tropical Medicine and Faculty of Veterinary Science, University of Liverpool, Liverpool, UK
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Makepeace BL, Jensen SA, Laney SJ, Nfon CK, Njongmeta LM, Tanya VN, Williams SA, Bianco AE, Trees AJ. Immunisation with a multivalent, subunit vaccine reduces patent infection in a natural bovine model of onchocerciasis during intense field exposure. PLoS Negl Trop Dis 2009; 3:e544. [PMID: 19901988 PMCID: PMC2770122 DOI: 10.1371/journal.pntd.0000544] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2009] [Accepted: 10/07/2009] [Indexed: 11/19/2022] Open
Abstract
Human onchocerciasis, caused by the filarial nematode Onchocerca volvulus, is controlled almost exclusively by the drug ivermectin, which prevents pathology by targeting the microfilariae. However, this reliance on a single control tool has led to interest in vaccination as a potentially complementary strategy. Here, we describe the results of a trial in West Africa to evaluate a multivalent, subunit vaccine for onchocerciasis in the naturally evolved host-parasite relationship of Onchocerca ochengi in cattle. Naïve calves, reared in fly-proof accommodation, were immunised with eight recombinant antigens of O. ochengi, administered separately with either Freund's adjuvant or alum. The selected antigens were orthologues of O. volvulus recombinant proteins that had previously been shown to confer protection against filarial larvae in rodent models and, in some cases, were recognised by serum antibodies from putatively immune humans. The vaccine was highly immunogenic, eliciting a mixed IgG isotype response. Four weeks after the final immunisation, vaccinated and adjuvant-treated control calves were exposed to natural parasite transmission by the blackfly vectors in an area of Cameroon hyperendemic for O. ochengi. After 22 months, all the control animals had patent infections (i.e., microfilaridermia), compared with only 58% of vaccinated cattle (P = 0.015). This study indicates that vaccination to prevent patent infection may be an achievable goal in onchocerciasis, reducing both the pathology and transmissibility of the infection. The cattle model has also demonstrated its utility for preclinical vaccine discovery, although much research will be required to achieve the requisite target product profile of a clinical candidate. River blindness, or onchocerciasis, is caused by a parasitic worm (Onchocerca volvulus) that is transmitted by blood-feeding blackflies, which breed in fast-flowing rivers. More than 37 million people are infected and may experience visual impairment and/or severe dermatitis. Control of onchocerciasis is largely dependent on a single drug, ivermectin. Whilst this is extremely effective at killing the worms' offspring (microfilariae) and preventing symptoms, ivermectin does not eliminate the long-lived adult parasites or always stop transmission. Consequently, treatments must be repeated for many years, and drug resistance may be emerging. Against this background, a vaccine against onchocerciasis would provide an important additional tool to sustain effective control. In this study, we evaluated eight worm antigens as vaccine components in cattle, which are often parasitized by O. ochengi (the closest relative of O. volvulus) in West Africa. Twelve uninfected animals received all eight antigens and were exposed to natural transmission of O. ochengi alongside 13 unvaccinated cattle. After almost two years, 92% of vaccinated animals had acquired adult worms, but only 58% were positive for microfilariae; whereas 100% of unvaccinated animals harboured both parasite stages. This suggests that a vaccine against microfilariae to prevent development of disease in humans may be achievable.
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Affiliation(s)
- Benjamin L. Makepeace
- Veterinary Parasitology Group, Liverpool School of Tropical Medicine and Faculty of Veterinary Science, University of Liverpool, Liverpool, United Kingdom
| | - Siv Aina Jensen
- Veterinary Parasitology Group, Liverpool School of Tropical Medicine and Faculty of Veterinary Science, University of Liverpool, Liverpool, United Kingdom
| | - Sandra J. Laney
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
| | - Charles K. Nfon
- Veterinary Parasitology Group, Liverpool School of Tropical Medicine and Faculty of Veterinary Science, University of Liverpool, Liverpool, United Kingdom
- Institut de Recherche Agricole pour le Développement, Wakwa, Adamawa Region, Cameroon
| | - Leo M. Njongmeta
- Veterinary Parasitology Group, Liverpool School of Tropical Medicine and Faculty of Veterinary Science, University of Liverpool, Liverpool, United Kingdom
| | - Vincent N. Tanya
- Institut de Recherche Agricole pour le Développement, Wakwa, Adamawa Region, Cameroon
| | - Steven A. Williams
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
- Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, Massachusetts, United States of America
| | - Albert E. Bianco
- Veterinary Parasitology Group, Liverpool School of Tropical Medicine and Faculty of Veterinary Science, University of Liverpool, Liverpool, United Kingdom
| | - Alexander J. Trees
- Veterinary Parasitology Group, Liverpool School of Tropical Medicine and Faculty of Veterinary Science, University of Liverpool, Liverpool, United Kingdom
- * E-mail:
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Dec Bronsvoort BM, Makepeace BL, Renz A, Tanya VN, Fleckenstein L, Ekale D, Trees AJ. UMF-078: A modified flubendazole with potent macrofilaricidal activity against Onchocerca ochengi in African cattle. Parasit Vectors 2008; 1:18. [PMID: 18570639 PMCID: PMC2464590 DOI: 10.1186/1756-3305-1-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2008] [Accepted: 06/20/2008] [Indexed: 11/10/2022] Open
Abstract
UNLABELLED BACKGROUND Human onchocerciasis or river blindness, caused by the filarial nematode Onchocerca volvulus, is currently controlled using the microfilaricidal drug, ivermectin. However, ivermectin does not kill adult O. volvulus, and in areas with less than 65% ivermectin coverage of the population, there is no effect on transmission. Therefore, there is still a need for a macrofilaricidal drug. Using the bovine filarial nematode O. ochengi (found naturally in African cattle), the macrofilaricidal efficacy of the modified flubendazole, UMF-078, was investigated. METHODS Groups of 3 cows were treated with one of the following regimens: (a) a single dose of UMF-078 at 150 mg/kg intramuscularly (im), (b) 50 mg/kg im, (c) 150 mg/kg intraabomasally (ia), (d) 50 mg/kg ia, or (e) not treated (controls). RESULTS After treatment at 150 mg/kg im, nodule diameter, worm motility and worm viability (as measured by metabolic reduction of tetrazolium to formazan) declined significantly compared with pre-treatment values and concurrent controls. There was abrogation of embryogenesis and death of all adult worms by 24 weeks post-treatment (pt). Animals treated at 50 mg/kg im showed a decline in nodule diameter together with abrogated reproduction, reduced motility, and lower metabolic activity in isolated worms, culminating in approximately 50% worm mortality by 52 weeks pt. Worms removed from animals treated ia were not killed, but exhibited a temporary embryotoxic effect which had waned by 12 weeks pt in the 50 mg/kg ia group and by 24 weeks pt in the 150 mg/kg ia group. These differences could be explained by the different absorption rates and elimination half-lives for each dose and route of administration. CONCLUSION Although we did not observe any signs of mammalian toxicity in this trial with a single dose, other studies have raised concerns regarding neuro- and genotoxicity. Consequently, further evaluation of this compound has been suspended. Nonetheless, these results validate the molecular target of the benzimidazoles as a promising lead for rational design of macrofilaricidal drugs.
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Affiliation(s)
- Barend M Dec Bronsvoort
- Veterinary Parasitology, Liverpool School of Tropical Medicine/Faculty of Veterinary Science, University of Liverpool, Pembroke Place, Liverpool, UK.
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Allen JE, Adjei O, Bain O, Hoerauf A, Hoffmann WH, Makepeace BL, Schulz-Key H, Tanya VN, Trees AJ, Wanji S, Taylor DW. Of mice, cattle, and humans: the immunology and treatment of river blindness. PLoS Negl Trop Dis 2008; 2:e217. [PMID: 18446236 PMCID: PMC2323618 DOI: 10.1371/journal.pntd.0000217] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
River blindness is a seriously debilitating disease caused by the filarial parasite Onchocerca volvulus, which infects millions in Africa as well as in South and Central America. Research has been hampered by a lack of good animal models, as the parasite can only develop fully in humans and some primates. This review highlights the development of two animal model systems that have allowed significant advances in recent years and hold promise for the future. Experimental findings with Litomosoides sigmodontis in mice and Onchocerca ochengi in cattle are placed in the context of how these models can advance our ability to control the human disease.
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Affiliation(s)
- Judith E. Allen
- Institute for Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Ohene Adjei
- Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Odile Bain
- Museum National d'Histoire Naturelle, Paris, France
| | | | | | - Benjamin L. Makepeace
- Liverpool School of Tropical Medicine and Faculty of Veterinary Science, University of Liverpool, Liverpool, United Kingdom
| | | | - Vincent N. Tanya
- Institut de Recherche Agricole pour le Développement, Ngaoundéré, Cameroon
| | - Alexander J. Trees
- Liverpool School of Tropical Medicine and Faculty of Veterinary Science, University of Liverpool, Liverpool, United Kingdom
| | - Samuel Wanji
- Research Foundation in Tropical Diseases and Environment, Buea, Cameroon
| | - David W. Taylor
- Centre for Infectious Diseases, Royal (Dick) School for Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail:
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Nfon CK, Makepeace BL, Njongmeta LM, Tanya VN, Trees AJ. Lack of resistance after re-exposure of cattle cured of Onchocerca ochengi infection with oxytetracycline. Am J Trop Med Hyg 2007; 76:67-72. [PMID: 17255232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023] Open
Abstract
Although vector control and ivermectin chemotherapy have led to a dramatic reduction in the incidence of river blindness (onchocerciasis), there is a consensus that additional control tools are required to sustain and extend this success. The recognition of endosymbiotic bacteria (Wolbachia) in filariae and their targeting by antibiotics constitutes the most significant and practicable opportunity for a macrofilaricidal therapy in the short-to-medium-term. Using Onchocerca ochengi in cattle, an analog of human onchocerciasis, we have previously shown that oxytetracycline is macrofilaricidal, and protective immunity exists naturally in a subset of animals termed putatively immune. Here, we report that although 24 weeks of weekly oxytetracycline treatment eliminated adult worms, cured animals remained susceptible to re-infection by natural challenge when compared with putatively immune cattle. However, their susceptibility was not significantly different from that of concurrently exposed, heavily infected animals. Thus, cattle cured by oxytetracycline are neither hypo-susceptible nor hyper-susceptible.
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Affiliation(s)
- Charles K Nfon
- Liverpool School of Tropical Medicine and Faculty of Veterinary Science, University of Liverpool, Liverpool, United Kingdom
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Nfon CK, Makepeace BL, Njongmeta LM, Tanya VN, Bain O, Trees AJ. Eosinophils contribute to killing of adult Onchocerca ochengi within onchocercomata following elimination of Wolbachia. Microbes Infect 2006; 8:2698-705. [PMID: 16962357 DOI: 10.1016/j.micinf.2006.07.017] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2006] [Revised: 07/26/2006] [Accepted: 07/27/2006] [Indexed: 11/25/2022]
Abstract
Many filarial nematodes, including Onchocerca volvulus (the cause of human 'River Blindness'), have a mutually dependent relationship with Wolbachia bacteria. There has been much interest in Wolbachia as a chemotherapeutic target, since there are no macrofilaricidal drugs (i.e., lethal to adult worms) of low toxicity. Using the bovine parasite O. ochengi, we previously demonstrated that combined intensive and intermittent (COM) oxytetracycline treatment induces a sustained depletion of Wolbachia and is macrofilaricidal, whereas a short intensive regimen (SIR) is non-macrofilaricidal. To understand how targeting Wolbachia with oxytetracycline can lead to worm death, O. ochengi nodules (onchocercomata) were sequentially excised from cattle administered COM or SIR therapy, and cell infiltrates were microscopically quantified. Pre-treatment, worms were surrounded by neutrophils, with eosinophils rare or absent. At 8-12weeks after either regimen, eosinophils increased around worms and were observed degranulating on the cuticle. However, with the SIR treatment, neutrophils returned to predominance by 48weeks, while in the COM group, eosinophilia persisted. These observations suggest that accumulation of degranulating eosinophils over a prolonged period is a cause rather than an effect of parasite death, and the macrofilaricidal mechanism of antibiotics may relate to facilitation of eosinophil infiltration around worms by ablation of Wolbachia-mediated neutrophilia.
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Affiliation(s)
- Charles K Nfon
- Liverpool School of Tropical Medicine and Faculty of Veterinary Science, University of Liverpool, Pembroke Place, Liverpool L3 5QA, UK
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