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Cotes-Perdomo AP, Sánchez-Vialas A, Thomas R, Jenkins A, Uribe JE. New insights into the systematics of the afrotropical Amblyomma marmoreum complex (Acari: Ixodidae) and the genome of a novel Rickettsia africae strain using morphological and metagenomic approaches. Ticks Tick Borne Dis 2024; 15:102323. [PMID: 38387163 DOI: 10.1016/j.ttbdis.2024.102323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 02/01/2024] [Accepted: 02/13/2024] [Indexed: 02/24/2024]
Abstract
The Amblyomma marmoreum complex includes afrotropical species, such as Amblyomma sparsum, a three-host tick that parasitizes reptiles, birds, and mammals, and is a recognized vector of Ehrlichia ruminantium. However, the lack of morphological, genetic and ecological data on A. sparsum has caused considerable confusion in its identification. In this study, we used microscopy and metagenomic approaches to analyze A. sparsum ticks collected from a puff adder snake (Bitis arietans) in southwest Senegal (an endemic rickettsioses area) in order to supplement previous morphological descriptions, provide novel genomic data for the A. marmoreum complex, and describe the genome of a novel spotted fever group Rickettsia strain. Based on stereoscope and scanning electron microscopy (SEM) morphological evaluations, we provide high-quality images and new insights about punctation and enameling in the adult male of A. sparsum to facilitate identification for future studies. The metagenomic approach allowed us assembly the complete mitochondrial genome of A. sparsum, as well as the nearly entire chromosome and complete plasmid sequences of a novel Rickettsia africae strain. Phylogenomic analyses demonstrated a close relationship between A. sparsum and Amblyomma nuttalli for the first time and confirmed the position of A. sparsum within the A. marmoreum complex. Our results provide new insights into the systematics of A. sparsum and A. marmoreum complex, as well as the genetic diversity of R. africae in the Afrotropical region. Future studies should consider the possibility that A. sparsum may be a vector for R. africae.
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Affiliation(s)
- Andrea P Cotes-Perdomo
- Department of Natural Sciences and Environmental Health, Faculty of Technology, Natural Sciences and Maritime Sciences, University of South-Eastern, Norway; Department of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales (MNCN-CSIC), 2José Gutiérrez Abascal 2, Madrid 28006, Spain
| | - Alberto Sánchez-Vialas
- Department of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales (MNCN-CSIC), 2José Gutiérrez Abascal 2, Madrid 28006, Spain
| | - Richard Thomas
- Facultad de Ciencias Veterinarias, Departamento de Ciencia Animal, Universidad de Concepción, Chillán, Chile
| | - Andrew Jenkins
- Department of Natural Sciences and Environmental Health, Faculty of Technology, Natural Sciences and Maritime Sciences, University of South-Eastern, Norway
| | - Juan E Uribe
- Department of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales (MNCN-CSIC), 2José Gutiérrez Abascal 2, Madrid 28006, Spain.
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Pillay A, Nyangiwe N, Mukaratirwa S. Low genetic diversity and population structuring of Amblyomma hebraeum and Rickettsia africae from coastal and inland regions in the Eastern Cape Province of South Africa. MEDICAL AND VETERINARY ENTOMOLOGY 2023; 37:275-285. [PMID: 36468449 PMCID: PMC10191886 DOI: 10.1111/mve.12629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Accepted: 11/16/2022] [Indexed: 05/18/2023]
Abstract
Amblyomma hebraeum is the main vector of Rickettsia africae, the causative agent of African tick bite fever in southern Africa. Because pathogen dispersal is known to be influenced by tick adaptations to climate or host species, this study aimed to analyse the genetic diversity of A. hebraeum and R. africae infection of ticks collected from cattle in the Eastern Cape province of South Africa. DNA was extracted, amplified, and sequenced for the COI and ITS2 markers from A. hebraeum samples and the 17 kDa and ompA genes for rickettsial detection. Between six and ten haplotypes were identified from 40 COI and 31 ITS2 sequences; however, no population structuring was observed among sites (ΦST = 0.22, p < 0.05). All A. hebraeum isolates clustered with southern Africa GenBank isolates. Rickettsia africae was detected in 46.92% (95% CI = 41%-53%, n = 260) of ticks. All R. africae isolates clustered with strain PELE and Chucks, which were reported previously from South Africa. These results confirm that A. hebraeum populations are undergoing a recent population expansion driven by cattle movement, facilitating local and long dispersal events across the Eastern Cape province.
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Affiliation(s)
- Alicia Pillay
- School of Life Sciences, Biological Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
| | - Nkululeko Nyangiwe
- Department of Rural Development and Agrarian Reform, Animal Science, Döhne Agricultural Development Institute, Stutterheim, South Africa
- Department of Agriculture and Animal Health, University of South Africa, Florida, South Africa
| | - Samson Mukaratirwa
- School of Life Sciences, Biological Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Westville Campus, Durban, South Africa
- One Health Center for Zoonoses and Tropical Veterinary Medicine, Ross University School of Veterinary Medicine, Basseterre, St. Kitts, West Indies
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Distribution and Prevalence of Anaplasmataceae, Rickettsiaceae and Coxiellaceae in African Ticks: A Systematic Review and Meta-Analysis. Microorganisms 2023; 11:microorganisms11030714. [PMID: 36985288 PMCID: PMC10051480 DOI: 10.3390/microorganisms11030714] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 03/06/2023] [Accepted: 03/08/2023] [Indexed: 03/12/2023] Open
Abstract
In Africa, ticks continue to be a major hindrance to the improvement of the livestock industry due to tick-borne pathogens that include Anaplasma, Ehrlichia, Rickettsia and Coxiella species. A systemic review and meta-analysis were conducted here and highlighted the distribution and prevalence of these tick-borne pathogens in African ticks. Relevant publications were searched in five electronic databases and selected using inclusion/exclusion criteria, resulting in 138 and 78 papers included in the qualitative and quantitative analysis, respectively. Most of the studies focused on Rickettsia africae (38 studies), followed by Ehrlichia ruminantium (27 studies), Coxiella burnetii (20 studies) and Anaplasma marginale (17 studies). A meta-analysis of proportions was performed using the random-effects model. The highest prevalence was obtained for Rickettsia spp. (18.39%; 95% CI: 14.23–22.85%), R. africae (13.47%; 95% CI: 2.76–28.69%), R. conorii (11.28%; 95% CI: 1.77–25.89%), A. marginale (12.75%; 95% CI: 4.06–24.35%), E. ruminantium (6.37%; 95% CI: 3.97–9.16%) and E. canis (4.3%; 95% CI: 0.04–12.66%). The prevalence of C. burnetii was low (0%; 95% CI: 0–0.25%), with higher prevalence for Coxiella spp. (27.02%; 95% CI: 10.83–46.03%) and Coxiella-like endosymbionts (70.47%; 95% CI: 27–99.82%). The effect of the tick genera, tick species, country and other variables were identified and highlighted the epidemiology of Rhipicephalus ticks in the heartwater; affinity of each Rickettsia species for different tick genera; dominant distribution of A. marginale, R. africae and Coxiella-like endosymbionts in ticks and a low distribution of C. burnetii in African hard ticks.
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Analysis of the Type 4 Effectome across the Genus Rickettsia. Int J Mol Sci 2022; 23:ijms232415513. [PMID: 36555155 PMCID: PMC9779031 DOI: 10.3390/ijms232415513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/05/2022] [Accepted: 12/06/2022] [Indexed: 12/13/2022] Open
Abstract
Rickettsia are obligate intracellular bacteria primarily carried by arthropod hosts. The genus Rickettsia contains several vertebrate pathogens vectored by hematophagous arthropods. Despite the potential for disease, our understanding of Rickettsias are limited by the difficulties associated with growing and manipulating obligate intracellular bacteria. To aid with this, our lab conducted an analysis of eight genomes and three plasmids from across the genus Rickettsia. Using OPT4e, a learning algorithm-based program designed to identify effector proteins secreted by the type 4 secretion system, we generated a putative effectome for the genus. We then consolidated effectors into homolog sets to identify effectors unique to Rickettsia with different life strategies or evolutionary histories. We also compared predicted effectors to non-effectors for differences in G+C content and gene splitting. Based on this analysis, we predicted 1571 effectors across the genus, resulting in 604 homolog sets. Each species had unique homolog sets, while 42 were present in all eight species analyzed. Effectors were flagged in association with pathogenic, tick and flea-borne Rickettsia. Predicted effectors also varied in G+C content and frequency of gene splitting as compared to non-effectors. Species effector repertoires show signs of expansion, degradation, and horizontal acquisition associated with lifestyle and lineage.
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Moerbeck L, Domingos A, Antunes S. Tick-Borne Rickettsioses in the Iberian Peninsula. Pathogens 2022; 11:pathogens11111377. [PMID: 36422628 PMCID: PMC9695430 DOI: 10.3390/pathogens11111377] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 11/13/2022] [Accepted: 11/16/2022] [Indexed: 11/19/2022] Open
Abstract
Tick-borne rickettsioses (TBR) are caused by obligate, intracellular bacteria of the spotted-fever group (SFG) of the genus Rickettsia (Order Rickettsiales), transmitted by hard ticks. TBR are one of the oldest known vector-borne zoonoses and pose a threat to both human and animal health, as over the years, new SFG Rickettsia spp. have been reported worldwide with the potential to be human pathogens. In Portugal and Spain, the countries that constitute the Iberian Peninsula, reported TB rickettsiae causing human disease include Rickettsia conorii conorii, Rickettsia conorii israelensis, Rickettsia slovaca, Rickettsia raoultii, Candidatus Rickettsia rioja, Rickettsia sibirica mongolitimonae, and Rickettsia monacensis. An allochthonous case of TBR caused by Rickettsia massiliae, described in Spain, points to the need to monitor disease epidemiology, to predict risks of exposure and spread of disease, and taking into account globalization and climate changes. This review aims to provide up-to-date information on the status of TBR in the Iberian Peninsula, as well as to show the importance of a national and international collaborative epidemiology surveillance network, towards monitoring Rickettsia spp. circulation in both Portugal and Spain.
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Onyiche TE, Labruna MB, Saito TB. Unraveling the epidemiological relationship between ticks and rickettsial infection in Africa. FRONTIERS IN TROPICAL DISEASES 2022. [DOI: 10.3389/fitd.2022.952024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Tick-borne rickettsioses are emerging and re-emerging diseases of public health concern caused by over 30 species of Rickettsia. Ticks are obligate hematophagous arthropods with over 700 species of Ixodid ticks known worldwide. The escalating geographical dispersal of tick vectors and concomitant increase in the incidences of tick-borne diseases have fueled interest in the ecology of tick-borne pathogens. This review focuses on aspects of the Rickettsia pathogen, including biology, taxonomy, phylogeny, genetic diversity, epidemiology of the disease, and the role of vertebrate host in the perpetuation of rickettsioses in Africa. Our review also highlights some of the species of Rickettsia that are responsible for disease, the role of tick vectors (both hard and soft ticks) and the species of Rickettsia associated with diverse tick species across the continent. Additionally, this article emphasizes the evolutionary perspective of rickettsiae perpetuation and the possible role of amplifying vertebrate host and other small mammals, domestic animals and wildlife in the epidemiology of Rickettsia species. We also specifically, discussed the role of avian population in the epidemiology of SFG rickettsiae. Furthermore, we highlighted tick-borne rickettsioses among travelers due to African tick-bite fever (ATBF) and the challenges to surveillance of rickettsial infection, and research on rickettsiology in Africa. Our review canvasses the need for more rickettsiologists of African origin based within the continent to further research towards understanding the biology, characterization, and species distribution, including the competent tick vectors involved in their transmission of rickettsiae across the continent in collaboration with established researchers in western countries. We further highlighted the need for proper funding to encourage research despite competing demands for resources across the various sectors. We finalize by discussing the similarities between rickettsial diseases around the world and which steps need to be taken to help foster our understanding on the eco-epidemiology of rickettsioses by bridging the gap between the growing epidemiological data and the molecular characterization of Rickettsia species.
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Abstract
Ticks are hematophagous ectoparasites capable of transmitting multiple human pathogens. Environmental changes have supported the expansion of ticks into new geographical areas that have become the epicenters of tick-borne diseases (TBDs). The spotted fever group (SFG) of Rickettsia frequently infects ticks and causes tick-transmitted rickettsioses in areas of endemicity where ixodid ticks support host transmission during blood feeding. Ticks also serve as a reservoir for SFG Rickettsia. Among the members of SFG Rickettsia, R. rickettsii causes Rocky Mountain spotted fever (RMSF), the most lethal TBD in the United States. Cases of RMSF have been reported for over a century in association with several species of ticks in the United States. However, the isolation of R. rickettsii from ticks has decreased, and recent serological and epidemiological studies suggest that novel species of SFG Rickettsia are responsible for the increased number of cases of RMSF-like rickettsioses in the United States. Recent analyses of rickettsial genomes and advances in genetic and molecular studies of Rickettsia provided insights into the biology of Rickettsia with the identification of conserved and unique putative virulence genes involved in the rickettsial life cycle. Thus, understanding Rickettsia-host-tick interactions mediating successful disease transmission and pathogenesis for SFG rickettsiae remains an active area of research. This review summarizes recent advances in understanding how SFG Rickettsia species coopt and manipulate ticks and mammalian hosts to cause rickettsioses, with a particular emphasis on newly described or emerging SFG Rickettsia species.
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Assembly and Comparison of Ca. Neoehrlichia mikurensis Genomes. Microorganisms 2022; 10:microorganisms10061134. [PMID: 35744652 PMCID: PMC9227406 DOI: 10.3390/microorganisms10061134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 05/27/2022] [Accepted: 05/30/2022] [Indexed: 11/17/2022] Open
Abstract
Ca. Neoehrlichia mikurensis is widely prevalent in I. ricinus across Europe and has been associated with human disease. However, diagnostic modalities are limited, and much is still unknown about its biology. Here, we present the first complete Ca. Neoehrlichia mikurensis genomes directly derived from wildlife reservoir host tissues, using both long- and short-read sequencing technologies. This pragmatic approach provides an alternative to obtaining sufficient material from clinical cases, a difficult task for emerging infectious diseases, and to expensive and challenging bacterial isolation and culture methods. Both genomes exhibit a larger chromosome than the currently available Ca. Neoehrlichia mikurensis genomes and expand the ability to find new targets for the development of supportive laboratory diagnostics in the future. Moreover, this method could be utilized for other tick-borne pathogens that are difficult to culture.
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Pillay A, Manyangadze T, Mukaratirwa S. Prevalence of Rickettsia africae in tick vectors collected from mammalian hosts in sub-Saharan Africa: A systematic review and meta-analysis. Ticks Tick Borne Dis 2022; 13:101960. [DOI: 10.1016/j.ttbdis.2022.101960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 04/08/2022] [Accepted: 04/21/2022] [Indexed: 11/29/2022]
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10
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Genomic evolution and adaptation of arthropod-associated Rickettsia. Sci Rep 2022; 12:3807. [PMID: 35264613 PMCID: PMC8907221 DOI: 10.1038/s41598-022-07725-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 02/16/2022] [Indexed: 11/17/2022] Open
Abstract
Rickettsia species are endosymbionts hosted by arthropods and are known to cause mild to fatal diseases in humans. Here, we analyse the evolution and diversity of 34 Rickettsia species using a pangenomic meta-analysis (80 genomes/41 plasmids). Phylogenomic trees showed that Rickettsia spp. diverged into two Spotted Fever groups, a Typhus group, a Canadensis group and a Bellii group, and may have inherited their plasmids from an ancestral plasmid that persisted in some strains or may have been lost by others. The results suggested that the ancestors of Rickettsia spp. might have infected Acari and/or Insecta and probably diverged by persisting inside and/or switching hosts. Pangenomic analysis revealed that the Rickettsia genus evolved through a strong interplay between genome degradation/reduction and/or expansion leading to possible distinct adaptive trajectories. The genus mainly shared evolutionary relationships with α-proteobacteria, and also with γ/β/δ-proteobacteria, cytophagia, actinobacteria, cyanobacteria, chlamydiia and viruses, suggesting lateral exchanges of several critical genes. These evolutionary processes have probably been orchestrated by an abundance of mobile genetic elements, especially in the Spotted Fever and Bellii groups. In this study, we provided a global evolutionary genomic view of the intracellular Rickettsia that may help our understanding of their diversity, adaptation and fitness.
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Ticks and their epidemiological role in Slovakia: from the past till present. Biologia (Bratisl) 2021; 77:1575-1610. [PMID: 34548672 PMCID: PMC8446484 DOI: 10.1007/s11756-021-00845-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 07/06/2021] [Indexed: 01/26/2023]
Abstract
In Slovakia, 22 tick species have been found to occur to date. Among them, Ixodes ricinus, Dermacentor reticulatus, D. marginatus and marginally Haemaphysalis concinna, H. inermis and H. punctata have been identified as the species of public health relevance. Ticks in Slovakia were found to harbour and transmit zoonotic and/or potentially zoonotic agents such as tick-borne encephalitis virus (TBEV), spirochaetes of the Borrelia burgdorferi sensu lato (s.l.) complex, the relapsing fever sprirochaete Borrelia miyamotoi, bacteria belonging to the orders Rickettsiales (Rickettsia spp., Anaplasma phagocytophilum, Neoehrlichia mikurensis), Legionellales (Coxiella burnetii), and Thiotrichales (Francisella tularensis), and Babesia spp. parasites (order Piroplasmida). Ixodes ricinus is the principal vector of the largest variety of microorganisms including viruses, bacteria and piroplasms. TBEV, B. burgdorferi s.l., rickettsiae of the spotted fever group, C. burnetii and F. tularensis have been found to cause serious diseases in humans, whereas B. miyamotoi, A. phagocytophilum, N. mikurensis, Babesia microti, and B. venatorum pose lower or potential risk to humans. Distribution of TBEV has a focal character. During the last few decades, new tick-borne encephalitis (TBE) foci and their spread to new areas have been registered and TBE incidence rates have increased. Moreover, Slovakia reports the highest rates of alimentary TBE infections among the European countries. Lyme borreliosis (LB) spirochaetes are spread throughout the distribution range of I. ricinus. Incidence rates of LB have shown a slightly increasing trend since 2010. Only a few sporadic cases of human rickettsiosis, anaplasmosis and babesiosis have been confirmed thus far in Slovakia. The latest large outbreaks of Q fever and tularaemia were recorded in 1993 and 1967, respectively. Since then, a few human cases of Q fever have been reported almost each year. Changes in the epidemiological characteristics and clinical forms of tularaemia have been observed during the last few decades. Global changes and development of modern molecular tools led to the discovery and identification of emerging or new tick-borne microorganisms and symbionts with unknown zoonotic potential. In this review, we provide a historical overview of research on ticks and tick-borne pathogens in Slovakia with the most important milestones and recent findings, and outline future directions in the investigation of ticks as ectoparasites and vectors of zoonotic agents and in the study of tick-borne diseases.
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McGinn J, Lamason RL. The enigmatic biology of rickettsiae: recent advances, open questions and outlook. Pathog Dis 2021; 79:ftab019. [PMID: 33784388 PMCID: PMC8035066 DOI: 10.1093/femspd/ftab019] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 03/26/2021] [Indexed: 02/05/2023] Open
Abstract
Rickettsiae are obligate intracellular bacteria that can cause life-threatening illnesses and are among the oldest known vector-borne pathogens. Members of this genus are extraordinarily diverse and exhibit a broad host range. To establish intracellular infection, Rickettsia species undergo complex, multistep life cycles that are encoded by heavily streamlined genomes. As a result of reductive genome evolution, rickettsiae are exquisitely tailored to their host cell environment but cannot survive extracellularly. This host-cell dependence makes for a compelling system to uncover novel host-pathogen biology, but it has also hindered experimental progress. Consequently, the molecular details of rickettsial biology and pathogenesis remain poorly understood. With recent advances in molecular biology and genetics, the field is poised to start unraveling the molecular mechanisms of these host-pathogen interactions. Here, we review recent discoveries that have shed light on key aspects of rickettsial biology. These studies have revealed that rickettsiae subvert host cells using mechanisms that are distinct from other better-studied pathogens, underscoring the great potential of the Rickettsia genus for revealing novel biology. We also highlight several open questions as promising areas for future study and discuss the path toward solving the fundamental mysteries of this neglected and emerging human pathogen.
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Affiliation(s)
- Jon McGinn
- Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, United States
| | - Rebecca L Lamason
- Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, United States
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13
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Salje J. Cells within cells: Rickettsiales and the obligate intracellular bacterial lifestyle. Nat Rev Microbiol 2021; 19:375-390. [PMID: 33564174 DOI: 10.1038/s41579-020-00507-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/16/2020] [Indexed: 01/01/2023]
Abstract
The Rickettsiales are a group of obligate intracellular vector-borne Gram-negative bacteria that include many organisms of clinical and agricultural importance, including Anaplasma spp., Ehrlichia chaffeensis, Wolbachia, Rickettsia spp. and Orientia tsutsugamushi. This Review provides an overview of the current state of knowledge of the biology of these bacteria and their interactions with host cells, with a focus on pathogenic species or those that are otherwise important for human health. This includes a description of rickettsial genomics, bacterial cell biology, the intracellular lifestyles of Rickettsiales and the mechanisms by which they induce and evade the innate immune response.
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Affiliation(s)
- Jeanne Salje
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK. .,Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. .,Public Health Research Institute, Rutgers University, Newark, NJ, USA.
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14
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Chiuya T, Masiga DK, Falzon LC, Bastos ADS, Fèvre EM, Villinger J. Tick-borne pathogens, including Crimean-Congo haemorrhagic fever virus, at livestock markets and slaughterhouses in western Kenya. Transbound Emerg Dis 2020; 68:2429-2445. [PMID: 33142046 PMCID: PMC8359211 DOI: 10.1111/tbed.13911] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 10/26/2020] [Accepted: 10/31/2020] [Indexed: 12/14/2022]
Abstract
Vectors of emerging infectious diseases have expanded their distributional ranges in recent decades due to increased global travel, trade connectivity and climate change. Transboundary range shifts, arising from the continuous movement of humans and livestock across borders, are of particular disease control concern. Several tick-borne diseases are known to circulate between eastern Uganda and the western counties of Kenya, with one fatal case of Crimean-Congo haemorrhagic fever (CCHF) reported in 2000 in western Kenya. Recent reports of CCHF in Uganda have highlighted the risk of cross-border disease translocation and the importance of establishing inter-epidemic, early warning systems to detect possible outbreaks. We therefore carried out surveillance of tick-borne zoonotic pathogens at livestock markets and slaughterhouses in three counties of western Kenya that neighbour Uganda. Ticks and other ectoparasites were collected from livestock and identified using morphological keys. The two most frequently sampled tick species were Rhipicephalus decoloratus (35%) and Amblyomma variegatum (30%); Ctenocephalides felis fleas and Haematopinus suis lice were also present. In total, 486 ticks, lice and fleas were screened for pathogen presence using established molecular workflows incorporating high-resolution melting analysis and identified through sequencing of PCR products. We detected CCHF virus in Rh. decoloratus and Rhipicephalus sp. cattle ticks, and 82 of 96 pools of Am. variegatum were positive for Rickettsia africae. Apicomplexan protozoa and bacteria of veterinary importance, such as Theileria parva, Babesia bigemina and Anaplasma marginale, were primarily detected in rhipicephaline ticks. Our findings show the presence of several pathogens of public health and veterinary importance in ticks from livestock at livestock markets and slaughterhouses in western Kenya. Confirmation of CCHF virus, a Nairovirus that causes haemorrhagic fever with a high case fatality rate in humans, highlights the risk of under-diagnosed zoonotic diseases and calls for continuous surveillance and the development of preventative measures.
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Affiliation(s)
- Tatenda Chiuya
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya.,Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Daniel K Masiga
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Laura C Falzon
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Neston, UK.,International Livestock Research Institute, Nairobi, Kenya
| | - Armanda D S Bastos
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Eric M Fèvre
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Neston, UK.,International Livestock Research Institute, Nairobi, Kenya
| | - Jandouwe Villinger
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
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15
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Ehlers J, Krüger A, Rakotondranary SJ, Ratovonamana RY, Poppert S, Ganzhorn JU, Tappe D. Molecular detection of Rickettsia spp., Borrelia spp., Bartonella spp. and Yersinia pestis in ectoparasites of endemic and domestic animals in southwest Madagascar. Acta Trop 2020; 205:105339. [PMID: 31935354 DOI: 10.1016/j.actatropica.2020.105339] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 01/09/2020] [Accepted: 01/10/2020] [Indexed: 12/16/2022]
Abstract
Little is known about the presence of vector-borne bacteria in southwest Madagascar. Anthropogenic alteration of natural habitats represents an important driver for the emergence of new diseases. Especially the involvement of livestock and the involuntary maintaining of invasive synanthropic animals (particularly rats) facilitate disease transmission from wildlife to humans and associated animals and vice versa. The dissemination or acquisition of ectoparasites is most likely in regions where human/wildlife contact is increasing. Little is known about the presence of vector-borne bacteria in southwest Madagascar. In 2016 and 2017, ectoparasites were collected from various introduced (cattle and goats, cats, dogs and chicken, rats and mice) and native animal species (mouse lemurs [Microcebus griseorufus], Grandidier's mongooses [Galidictis grandidieri], bastard big-footed mice [Macrotarsomys bastardi], greater hedgehog tenrecs [Setifer setosus] and lesser hedgehog tenrecs [Echinops telfairi]) in the northern portion of Tsimanampetsotsa National Park and the adjacent littoral region. Thirteen species of blood-feeding ectoparasites (235 individuals of ticks [5 species], 414 lice [4 spp.] and 389 fleas [4 spp.]) were investigated for the presence and identity of rickettsiae, borreliae, bartonellae and Yersinia pestis using PCR techniques. Rickettsia spp. were detected in every single ectoparasite species (Amblyomma variegatum, A. chabaudi, Rhipicephalus microplus, Haemaphysalis simplex, Argas echinops, Ctenocephalides felis, Echidnophaga gallinacea, Pulex irritans, Xenopsylla cheopis, Haematopinus quadripertusus, Linognathus africanus, L. vituli, Lemurpediculus verruculosus). Lice and ticks were found harboring rickettsiae identified as Rickettsia africae, while Rickettsia felis-like bacteria were associated with fleas. Borrelia spp. were detected in 5% of H. simplex and 1% of R. microplus ticks. Bartonella spp. were detected in 40% of H. quadripertusus pools and in 5% of L. verruculosus pools. Y. pestis was detected in X. cheopis and E. gallinacea fleas collected from a rat. This study presents the detection of a broad spectrum of vector-borne bacteria including potential pathogens, and an unexpected finding of Y. pestis far off the known plague foci in Madagascar.
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Uelze L, Grützke J, Borowiak M, Hammerl JA, Juraschek K, Deneke C, Tausch SH, Malorny B. Typing methods based on whole genome sequencing data. ONE HEALTH OUTLOOK 2020; 2:3. [PMID: 33829127 PMCID: PMC7993478 DOI: 10.1186/s42522-020-0010-1] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 01/08/2020] [Indexed: 05/12/2023]
Abstract
Whole genome sequencing (WGS) of foodborne pathogens has become an effective method for investigating the information contained in the genome sequence of bacterial pathogens. In addition, its highly discriminative power enables the comparison of genetic relatedness between bacteria even on a sub-species level. For this reason, WGS is being implemented worldwide and across sectors (human, veterinary, food, and environment) for the investigation of disease outbreaks, source attribution, and improved risk characterization models. In order to extract relevant information from the large quantity and complex data produced by WGS, a host of bioinformatics tools has been developed, allowing users to analyze and interpret sequencing data, starting from simple gene-searches to complex phylogenetic studies. Depending on the research question, the complexity of the dataset and their bioinformatics skill set, users can choose between a great variety of tools for the analysis of WGS data. In this review, we describe the relevant approaches for phylogenomic studies for outbreak studies and give an overview of selected tools for the characterization of foodborne pathogens based on WGS data. Despite the efforts of the last years, harmonization and standardization of typing tools are still urgently needed to allow for an easy comparison of data between laboratories, moving towards a one health worldwide surveillance system for foodborne pathogens.
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Affiliation(s)
- Laura Uelze
- Department for Biological Safety, German Federal Institute for Risk Assessment, BfR, Max-Dohrn Straße 8-10, 10589 Berlin, Germany
| | - Josephine Grützke
- Department for Biological Safety, German Federal Institute for Risk Assessment, BfR, Max-Dohrn Straße 8-10, 10589 Berlin, Germany
| | - Maria Borowiak
- Department for Biological Safety, German Federal Institute for Risk Assessment, BfR, Max-Dohrn Straße 8-10, 10589 Berlin, Germany
| | - Jens Andre Hammerl
- Department for Biological Safety, German Federal Institute for Risk Assessment, BfR, Max-Dohrn Straße 8-10, 10589 Berlin, Germany
| | - Katharina Juraschek
- Department for Biological Safety, German Federal Institute for Risk Assessment, BfR, Max-Dohrn Straße 8-10, 10589 Berlin, Germany
| | - Carlus Deneke
- Department for Biological Safety, German Federal Institute for Risk Assessment, BfR, Max-Dohrn Straße 8-10, 10589 Berlin, Germany
| | - Simon H. Tausch
- Department for Biological Safety, German Federal Institute for Risk Assessment, BfR, Max-Dohrn Straße 8-10, 10589 Berlin, Germany
| | - Burkhard Malorny
- Department for Biological Safety, German Federal Institute for Risk Assessment, BfR, Max-Dohrn Straße 8-10, 10589 Berlin, Germany
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17
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Li H, Zhang PH, Huang Y, Du J, Cui N, Yang ZD, Tang F, Fu FX, Li XM, Cui XM, Fan YD, Xing B, Li XK, Tong YG, Cao WC, Liu W. Isolation and Identification of Rickettsia raoultii in Human Cases: A Surveillance Study in 3 Medical Centers in China. Clin Infect Dis 2019; 66:1109-1115. [PMID: 29069294 DOI: 10.1093/cid/cix917] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 10/19/2017] [Indexed: 11/14/2022] Open
Abstract
Background Rickettsia raoultii is frequently detected in multiple tick species, whereas human infection remains scarcely studied. Methods A surveillance study was performed at 3 sentinel hospitals in China, to recruit participants with suspected tick exposure. Rickettsia raoultii infection was identified through polymerase chain reaction, followed by sequencing, and confirmed serologically. Isolation by cell culture was performed and the isolates were genome sequenced. Results Twenty-six subjects were determined to have R. raoultii infection, including 7 with asymptomatic infection, 15 with mild to moderate illness, and 4 with severe illness. Common nonspecific manifestations in the 19 patients with mild to moderate or severe illness included fever (100%), malaise (95%), myalgia (58%), lymphadenopathy (53%), and nausea (42%). Only 5% of them had rash, and 16% had eschar. Scalp eschar and neck lymphadenopathy after a tick bite syndrome was only seen in 2 patients. Of the 4 patients with severe complications, 3 developed pulmonary edema, and 1 developed clouding of consciousness and lethargy. Frequent abnormalities of laboratory testing included leukopenia, thrombocytopenia, lymphopenia, neutropenia, hypoproteinemia, and elevated levels of total bilirubin, hepatic aminotransferases, lactate dehydrogenase, and creatine kinase. All the 19 patients recovered without sequelae after receiving doxycycline treatment. Two R. raoultii strains were isolated, and a significantly less degraded genome was observed than other more virulent Rickettsia strains, indicating a low pathogenicity of the current strain. Conclusions Human infection with R. raoultii has a wide clinical spectrum that ranged from subclinical infection to severe complications. Physicians need to be aware of the high potential and clinical complexity of R. raoultii infection, to ensure appropriate testing and treatment in endemic regions.
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Affiliation(s)
- Hao Li
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology
| | - Pan-He Zhang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology
| | - Yong Huang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology
| | - Juan Du
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology
| | - Ning Cui
- The 154 Hospital, People's Liberation Army, Xinyang
| | | | - Fang Tang
- Center for Disease Control and Prevention of the Chinese Peoples' Armed Police Forces, Beijing
| | - Fei-Xiang Fu
- Center for Disease Control and Prevention of the Chinese Peoples' Armed Police Forces, Beijing
| | - Xiao-Mei Li
- Taishan Medical University, Tai'an, People's Republic of China
| | - Xiao-Ming Cui
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology
| | - Ya-Di Fan
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology
| | - Bo Xing
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology
| | - Xiao-Kun Li
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology
| | - Yi-Gang Tong
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology
| | - Wu-Chun Cao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology
| | - Wei Liu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology
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Phylogenetic, genomic, and biogeographic characterization of a novel and ubiquitous marine invertebrate-associated Rickettsiales parasite, Candidatus Aquarickettsia rohweri, gen. nov., sp. nov. ISME JOURNAL 2019; 13:2938-2953. [PMID: 31384012 PMCID: PMC6863919 DOI: 10.1038/s41396-019-0482-0] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 07/10/2019] [Accepted: 07/13/2019] [Indexed: 12/14/2022]
Abstract
Bacterial symbionts are integral to the health and homeostasis of invertebrate hosts. Notably, members of the Rickettsiales genus Wolbachia influence several aspects of the fitness and evolution of their terrestrial hosts, but few analogous partnerships have been found in marine systems. We report here the genome, phylogenetics, and biogeography of a ubiquitous and novel Rickettsiales species that primarily associates with marine organisms. We previously showed that this bacterium was found in scleractinian corals, responds to nutrient exposure, and is associated with reduced host growth and increased mortality. This bacterium, like other Rickettsiales, has a reduced genome indicative of a parasitic lifestyle. Phylogenetic analysis places this Rickettsiales within a new genus we define as “Candidatus Aquarickettsia.” Using data from the Earth Microbiome Project and SRA databases, we also demonstrate that members of “Ca. Aquarickettsia” are found globally in dozens of invertebrate lineages. The coral-associated “Candidatus A. rohweri” is the first finished genome in this new clade. “Ca. A. rohweri” lacks genes to synthesize most sugars and amino acids but possesses several genes linked to pathogenicity including Tlc, an antiporter that exchanges host ATP for ADP, and a complete Type IV secretion system. Despite its inability to metabolize nitrogen, “Ca. A. rohweri” possesses the NtrY-NtrX two-component system involved in sensing and responding to extracellular nitrogen. Given these data, along with visualization of the parasite in host tissues, we hypothesize that “Ca. A. rohweri” reduces coral health by consuming host nutrients and energy, thus weakening and eventually killing host cells. Last, we hypothesize that nutrient enrichment, which is increasingly common on coral reefs, encourages unrestricted growth of “Ca. A. rohweri” in its host by providing abundant N-rich metabolites to be scavenged.
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19
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Diop A, Raoult D, Fournier PE. Paradoxical evolution of rickettsial genomes. Ticks Tick Borne Dis 2018; 10:462-469. [PMID: 30448253 DOI: 10.1016/j.ttbdis.2018.11.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 08/08/2018] [Accepted: 11/09/2018] [Indexed: 01/08/2023]
Abstract
Rickettsia species are strictly intracellular bacteria that evolved approximately 150 million years ago from a presumably free-living common ancestor from the order Rickettsiales that followed a transition to an obligate intracellular lifestyle. Rickettsiae are best known as human pathogens vectored by various arthropods causing a range of mild to severe human diseases. As part of their obligate intracellular lifestyle, rickettsial genomes have undergone a convergent evolution that includes a strong genomic reduction resulting from progressive gene degradation, genomic rearrangements as well as a paradoxical expansion of various genetic elements, notably small RNAs and short palindromic elements whose role remains unknown. This reductive evolutionary process is not unique to members of the Rickettsia genus but is common to several human pathogenic bacteria. Gene loss, gene duplication, DNA repeat duplication and horizontal gene transfer all have shaped rickettsial genome evolution. Gene loss mostly involved amino-acid, ATP, LPS and cell wall component biosynthesis and transcriptional regulators, but with a high preservation of toxin-antitoxin (TA) modules, recombination and DNA repair proteins. Surprisingly the most virulent Rickettsia species were shown to have the most drastically reduced and degraded genomes compared to closely related species of milder pathogenesis. In contrast, the less pathogenic species harbored the greatest number of mobile genetic elements. Thus, this distinct evolutionary process observed in Rickettsia species may be correlated with the differences in virulence and pathogenicity observed in these obligate intracellular bacteria. However, future investigations are needed to provide novel insights into the evolution of genome sizes and content, for that a better understanding of the balance between proliferation and elimination of genetic material in these intracellular bacteria is required.
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Affiliation(s)
- Awa Diop
- UMR VITROME, Aix-Marseille University, IRD, Service de Santé des Armées, Assistance Publique-Hôpitaux de Marseille, Institut Hospitalo-Uuniversitaire Méditerranée Infection, 19-21 Boulevard Jean Moulin, 13005, Marseille, France
| | - Didier Raoult
- UMR MEPHI, Aix-Marseille University, IRD, Assistance Publique-Hôpitaux de Marseille, Institut Hospitalo-Uuniversitaire Méditerranée Infection, Marseille, France
| | - Pierre-Edouard Fournier
- UMR VITROME, Aix-Marseille University, IRD, Service de Santé des Armées, Assistance Publique-Hôpitaux de Marseille, Institut Hospitalo-Uuniversitaire Méditerranée Infection, 19-21 Boulevard Jean Moulin, 13005, Marseille, France.
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20
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Diop A, Raoult D, Fournier PE. Rickettsial genomics and the paradigm of genome reduction associated with increased virulence. Microbes Infect 2018; 20:401-409. [DOI: 10.1016/j.micinf.2017.11.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 10/06/2017] [Accepted: 11/15/2017] [Indexed: 11/29/2022]
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21
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A Concise Review of the Epidemiology and Diagnostics of Rickettsioses: Rickettsia and Orientia spp. J Clin Microbiol 2018; 56:JCM.01728-17. [PMID: 29769278 DOI: 10.1128/jcm.01728-17] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Rickettsioses are globally distributed and caused by the family Rickettsiaceae, which comprise a diverse and expanding list of organisms. These include two genera, Rickettsia and Orientia Serology has been traditionally the mainstay of diagnosis, although this has been limited by cross-reactions among closely related members and diminished sensitivity/utility in the acute phase of illness. Other techniques, such as nucleic acid amplification tests using blood specimens or tissue swabs/biopsy specimens, sequencing, and mass spectrometry, have emerged in recent years for both pathogen and vector identification. This paper provides a concise review of the rickettsioses and the traditional and newer technologies available for their diagnosis.
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Identification of rickettsial immunoreactive proteins using a proximity ligation assay Western blotting and the traditional immunoproteomic approach. Comp Immunol Microbiol Infect Dis 2018; 58:17-25. [DOI: 10.1016/j.cimid.2018.06.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 03/16/2018] [Accepted: 06/10/2018] [Indexed: 11/23/2022]
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23
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Cicala F, Moore JD, Cáceres-Martínez J, Del Río-Portilla MA, Hernández-Rodríguez M, Vásquez-Yeomans R, Rocha-Olivares A. Monomorphic pathogens: The case of Candidatus Xenohaliotis californiensis from abalone in California, USA and Baja California, Mexico. J Invertebr Pathol 2018; 154:19-23. [PMID: 29577877 DOI: 10.1016/j.jip.2018.03.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 03/15/2018] [Accepted: 03/21/2018] [Indexed: 10/17/2022]
Abstract
Withering syndrome (WS) is a chronic wasting disease affecting abalone species attributed to the pathogen Candidatus Xenohaliotis californiensis (CXc). Wild populations of blue (Haliotis fulgens) and yellow (H. corrugata) abalone have experienced unusual mortality rates since 2009 off the peninsula of Baja California and WS has been hypothesized as a possible cause. Currently, little information is available about the genetic diversity of CXc and particularly the possible existence of strains differing in pathogenicity. In a recent phylogenetic analysis, we characterized five coding genes from this rickettsial pathogen. Here, we analyze those genes and two additional intergenic non-coding regions following multi-locus sequence typing (MLST) and multi-spacer typing (MST) approaches to assess the genetic variability of CXc and its relationship with blue, yellow and red (H. rufescens) abalone. Moreover, we used 16S rRNA pyrosequencing reads from gut microbiomes of blue and yellow abalone to complete the genetic characterization of this prokaryote. The presence of CXc was investigated in more than 150 abalone of the three species; furthermore, a total of 385 DNA sequences and 7117 16S rRNA reads from Candidatus Xenohaliotis californiensis were used to evaluate its population genetic structure. Our findings suggest the absence of polymorphism in the DNA sequences of analyzed loci and the presence of a single lineage of CXc infecting abalone from California (USA) and Baja California (Mexico). We posit that the absence of genetic variably in this marine rickettsia may be the result of evolutionary and ecological processes.
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Affiliation(s)
- Francesco Cicala
- Molecular Ecology Laboratory, Department of Biological Oceanography, CICESE, Carretera Tijuana-Ensenada km 3918, Ensenada, Baja California 22860, Mexico
| | - James D Moore
- Bodega Marine Laboratory, University of California at Davis, P.O. Box 247, Bodega Bay, CA, USA
| | - Jorge Cáceres-Martínez
- Department of Aquaculture, CICESE, Carretera Tijuana-Ensenada km 3918, Ensenada Baja California 22860, Mexico
| | - Miguel A Del Río-Portilla
- Department of Aquaculture, CICESE, Carretera Tijuana-Ensenada km 3918, Ensenada Baja California 22860, Mexico
| | - Mónica Hernández-Rodríguez
- Department of Aquaculture, CICESE, Carretera Tijuana-Ensenada km 3918, Ensenada Baja California 22860, Mexico
| | - Rebeca Vásquez-Yeomans
- Department of Aquaculture, CICESE, Carretera Tijuana-Ensenada km 3918, Ensenada Baja California 22860, Mexico
| | - Axayácatl Rocha-Olivares
- Molecular Ecology Laboratory, Department of Biological Oceanography, CICESE, Carretera Tijuana-Ensenada km 3918, Ensenada, Baja California 22860, Mexico.
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Muñoz-Leal S, Martins TF, Luna LR, Rodriguez A, Labruna MB. A New Collection of Amblyomma parvitarsum (Acari: Ixodidae) in Peru, With Description of a Gynandromorph and Report of Rickettsia Detection. JOURNAL OF MEDICAL ENTOMOLOGY 2018; 55:464-467. [PMID: 29045695 DOI: 10.1093/jme/tjx194] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Indexed: 06/07/2023]
Abstract
Adult stages of Amblyomma parvitarsum Neumann parasitize wild and domestic camelids of the genera Lama and Vicugna in highlands of Andean Plateau and Patagonia. Within the Peruvian Andes, few reports have documented this tick-host association, and although reported in Chile and Argentina, Rickettsia-infected A. parvitarsum remains undocumented for this country. Here we report a new collection of A. parvitarsum from Peru, the finding of the first gynandromorph for the species and high prevalence of Rickettsia in adult stages.
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Affiliation(s)
- S Muñoz-Leal
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Avenue Prof. Orlando Marques de Paiva, Cidade Universitária, São Paulo, SP, Brazil
| | - T F Martins
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Avenue Prof. Orlando Marques de Paiva, Cidade Universitária, São Paulo, SP, Brazil
| | - L R Luna
- Laboratorio de Biología y Genética Molecular, Departamento de Microbiología y Parasitología Veterinaria, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, San Borja, Lima, Peru
| | - A Rodriguez
- Laboratorio de Biología y Genética Molecular, Departamento de Microbiología y Parasitología Veterinaria, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, San Borja, Lima, Peru
| | - M B Labruna
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Avenue Prof. Orlando Marques de Paiva, Cidade Universitária, São Paulo, SP, Brazil
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Bogovic P, Lotric-Furlan S, Korva M, Avsic-Zupanc T. African Tick-Bite Fever in Traveler Returning to Slovenia from Uganda. Emerg Infect Dis 2018; 22:1848-9. [PMID: 27648844 PMCID: PMC5038416 DOI: 10.3201/eid2210.160650] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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26
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Molecular Characterization of an Endozoicomonas-Like Organism Causing Infection in the King Scallop (Pecten maximus L.). Appl Environ Microbiol 2018; 84:AEM.00952-17. [PMID: 29150518 PMCID: PMC5772249 DOI: 10.1128/aem.00952-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Accepted: 11/10/2017] [Indexed: 11/20/2022] Open
Abstract
One of the fastest growing fisheries in the UK is the king scallop (Pecten maximus L.), also currently rated as the second most valuable fishery. Mass mortality events in scallops have been reported worldwide, often with the causative agent(s) remaining uncharacterized. In May 2013 and 2014, two mass mortality events affecting king scallops were recorded in the Lyme Bay marine protected area (MPA) in Southwest England. Histopathological examination showed gill epithelial tissues infected with intracellular microcolonies (IMCs) of bacteria resembling Rickettsia-like organisms (RLOs), often with bacteria released in vascular spaces. Large colonies were associated with cellular and tissue disruption of the gills. Ultrastructural examination confirmed the intracellular location of these organisms in affected epithelial cells. The 16S rRNA gene sequences of the putative IMCs obtained from infected king scallop gill samples, collected from both mortality events, were identical and had a 99.4% identity to 16S rRNA gene sequences obtained from “Candidatus Endonucleobacter bathymodioli” and 95% with Endozoicomonas species. In situ hybridization assays using 16S rRNA gene probes confirmed the presence of the sequenced IMC gene in the gill tissues. Additional DNA sequences of the bacterium were obtained using high-throughput (Illumina) sequencing, and bioinformatic analysis identified over 1,000 genes with high similarity to protein sequences from Endozoicomonas spp. (ranging from 77 to 87% identity). Specific PCR assays were developed and applied to screen for the presence of IMC 16S rRNA gene sequences in king scallop gill tissues collected at the Lyme Bay MPA during 2015 and 2016. There was 100% prevalence of the IMCs in these gill tissues, and the 16S rRNA gene sequences identified were identical to the sequence found during the previous mortality event. IMPORTANCE Molluscan mass mortalities associated with IMCs have been reported worldwide for many years; however, apart from histological and ultrastructural characterization, characterization of the etiological agents is limited. In the present work, we provide detailed molecular characterization of an Endozoicomonas-like organism (ELO) associated with an important commercial scallop species.
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27
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Akter A, Ooka T, Gotoh Y, Yamamoto S, Fujita H, Terasoma F, Kida K, Taira M, Nakadouzono F, Gokuden M, Hirano M, Miyashiro M, Inari K, Shimazu Y, Tabara K, Toyoda A, Yoshimura D, Itoh T, Kitano T, Sato MP, Katsura K, Mondal SI, Ogura Y, Ando S, Hayashi T. Extremely Low Genomic Diversity of Rickettsia japonica Distributed in Japan. Genome Biol Evol 2017; 9:124-133. [PMID: 28057731 PMCID: PMC5381555 DOI: 10.1093/gbe/evw304] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/27/2016] [Indexed: 12/25/2022] Open
Abstract
Rickettsiae are obligate intracellular bacteria that have small genomes as a result of reductive evolution. Many Rickettsia species of the spotted fever group (SFG) cause tick-borne diseases known as “spotted fevers”. The life cycle of SFG rickettsiae is closely associated with that of the tick, which is generally thought to act as a bacterial vector and reservoir that maintains the bacterium through transstadial and transovarial transmission. Each SFG member is thought to have adapted to a specific tick species, thus restricting the bacterial distribution to a relatively limited geographic region. These unique features of SFG rickettsiae allow investigation of how the genomes of such biologically and ecologically specialized bacteria evolve after genome reduction and the types of population structures that are generated. Here, we performed a nationwide, high-resolution phylogenetic analysis of Rickettsia japonica, an etiological agent of Japanese spotted fever that is distributed in Japan and Korea. The comparison of complete or nearly complete sequences obtained from 31 R. japonica strains isolated from various sources in Japan over the past 30 years demonstrated an extremely low level of genomic diversity. In particular, only 34 single nucleotide polymorphisms were identified among the 27 strains of the major lineage containing all clinical isolates and tick isolates from the three tick species. Our data provide novel insights into the biology and genome evolution of R. japonica, including the possibilities of recent clonal expansion and a long generation time in nature due to the long dormant phase associated with tick life cycles.
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Affiliation(s)
- Arzuba Akter
- Division of Microbiology, Department of Infectious Diseases, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
| | - Tadasuke Ooka
- Department of Microbiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Yasuhiro Gotoh
- Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Seigo Yamamoto
- Frontier Science Research Center, University of Miyazaki, Miyazaki, Japan
| | - Hiromi Fujita
- Mahara Institute of Medical Acarology, Tokushima, Japan
| | - Fumio Terasoma
- Wakayama Prefectural Research Center of Environment and Public Health, Wakayama, Japan
| | - Kouji Kida
- Okayama Prefectural Institute for Environmental Science and Public Health, Okayama, Japan
| | | | - Fumiko Nakadouzono
- Kagoshima Prefectural Institute for Environmental Research and Public Health, Kagoshima, Japan
| | - Mutsuyo Gokuden
- Kagoshima Prefectural Institute for Environmental Research and Public Health, Kagoshima, Japan
| | - Manabu Hirano
- Seihi Public Health Center of Nagasaki Prefecture, Nagasaki, Japan
| | - Mamoru Miyashiro
- Fukuoka City Institute for Health and Environment, Fukuoka, Japan
| | - Kouichi Inari
- Mahara Institute of Medical Acarology, Tokushima, Japan
| | - Yukie Shimazu
- Hiroshima Prefectural Technology Research Institute, Public Health and Environment Center, Hiroshima, Japan
| | - Kenji Tabara
- Department of Health and Welfare, Shimane Prefectural Government, Shimane, Japan
| | - Atsushi Toyoda
- Comparative Genomics Laboratory, National Institute of Genetics, Shizuoka, Japan
| | - Dai Yoshimura
- School of Life Science and Technology, Tokyo Institute of Technology, Tokyo, Japan
| | - Takehiko Itoh
- School of Life Science and Technology, Tokyo Institute of Technology, Tokyo, Japan
| | - Tomokazu Kitano
- Division of Microbiology, Department of Infectious Diseases, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
| | - Mitsuhiko P Sato
- Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Keisuke Katsura
- Frontier Science Research Center, University of Miyazaki, Miyazaki, Japan
| | - Shakhinur Islam Mondal
- Division of Microbiology, Department of Infectious Diseases, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
| | - Yoshitoshi Ogura
- Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Shuji Ando
- Department of Virology-1, National Institute of Infectious Diseases, Tokyo, Japan
| | - Tetsuya Hayashi
- Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan
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Wholly Rickettsia! Reconstructed Metabolic Profile of the Quintessential Bacterial Parasite of Eukaryotic Cells. mBio 2017; 8:mBio.00859-17. [PMID: 28951473 PMCID: PMC5615194 DOI: 10.1128/mbio.00859-17] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Reductive genome evolution has purged many metabolic pathways from obligate intracellular Rickettsia (Alphaproteobacteria; Rickettsiaceae). While some aspects of host-dependent rickettsial metabolism have been characterized, the array of host-acquired metabolites and their cognate transporters remains unknown. This dearth of information has thwarted efforts to obtain an axenic Rickettsia culture, a major impediment to conventional genetic approaches. Using phylogenomics and computational pathway analysis, we reconstructed the Rickettsia metabolic and transport network, identifying 51 host-acquired metabolites (only 21 previously characterized) needed to compensate for degraded biosynthesis pathways. In the absence of glycolysis and the pentose phosphate pathway, cell envelope glycoconjugates are synthesized from three imported host sugars, with a range of additional host-acquired metabolites fueling the tricarboxylic acid cycle. Fatty acid and glycerophospholipid pathways also initiate from host precursors, and import of both isoprenes and terpenoids is required for the synthesis of ubiquinone and the lipid carrier of lipid I and O-antigen. Unlike metabolite-provisioning bacterial symbionts of arthropods, rickettsiae cannot synthesize B vitamins or most other cofactors, accentuating their parasitic nature. Six biosynthesis pathways contain holes (missing enzymes); similar patterns in taxonomically diverse bacteria suggest alternative enzymes that await discovery. A paucity of characterized and predicted transporters emphasizes the knowledge gap concerning how rickettsiae import host metabolites, some of which are large and not known to be transported by bacteria. Collectively, our reconstructed metabolic network offers clues to how rickettsiae hijack host metabolic pathways. This blueprint for growth determinants is an important step toward the design of axenic media to rescue rickettsiae from the eukaryotic cell. A hallmark of obligate intracellular bacteria is the tradeoff of metabolic genes for the ability to acquire host metabolites. For species of Rickettsia, arthropod-borne parasites with the potential to cause serious human disease, the range of pilfered host metabolites is unknown. This information is critical for dissociating rickettsiae from eukaryotic cells to facilitate rickettsial genetic manipulation. In this study, we reconstructed the Rickettsia metabolic network and identified 51 host metabolites required to compensate patchwork Rickettsia biosynthesis pathways. Remarkably, some metabolites are not known to be transported by any bacteria, and overall, few cognate transporters were identified. Several pathways contain missing enzymes, yet similar pathways in unrelated bacteria indicate convergence and possible novel enzymes awaiting characterization. Our work illuminates the parasitic nature by which rickettsiae hijack host metabolism to counterbalance numerous disintegrated biosynthesis pathways that have arisen through evolution within the eukaryotic cell. This metabolic blueprint reveals what a Rickettsia axenic medium might entail.
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El Karkouri K, Kowalczewska M, Armstrong N, Azza S, Fournier PE, Raoult D. Multi-omics Analysis Sheds Light on the Evolution and the Intracellular Lifestyle Strategies of Spotted Fever Group Rickettsia spp. Front Microbiol 2017; 8:1363. [PMID: 28775717 PMCID: PMC5517468 DOI: 10.3389/fmicb.2017.01363] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 07/05/2017] [Indexed: 11/13/2022] Open
Abstract
Arthropod-borne Rickettsia species are obligate intracellular bacteria which are pathogenic for humans. Within this genus, Rickettsia slovaca and Rickettsia conorii cause frequent and potentially severe infections, whereas Rickettsia raoultii and Rickettsia massiliae cause rare and milder infections. All four species belong to spotted fever group (SFG) rickettsiae. However, R. slovaca and R. raoultii cause scalp eschar and neck lymphadenopathy (SENLAT) and are mainly associated with Dermacentor ticks, whereas the other two species cause Mediterranean spotted fever (MSF) and are mainly transmitted by Rhipicephalus ticks. To identify the potential genes and protein profiles and to understand the evolutionary processes that could, comprehensively, relate to the differences in virulence and pathogenicity observed between these four species, we compared their genomes and proteomes. The virulent and milder agents displayed divergent phylogenomic evolution in two major clades, whereas either SENLAT or MSF disease suggests a discrete convergent evolution of one virulent and one milder agent, despite their distant genetic relatedness. Moreover, the two virulent species underwent strong reductive genomic evolution and protein structural variations, as well as a probable loss of plasmid(s), compared to the two milder species. However, an abundance of mobilome genes was observed only in the less pathogenic species. After infecting Xenopus laevis cells, the virulent agents displayed less up-regulated than down-regulated proteins, as well as less number of identified core proteins. Furthermore, their similar and distinct protein profiles did not contain some genes (e.g., ompA/B and rickA) known to be related to rickettsial adhesion, motility and/or virulence, but may include other putative virulence-, antivirulence-, and/or disease-related proteins. The identified evolutionary forces herein may have a strong impact on intracellular expressions and strategies in these rickettsiae, and that may contribute to the emergence of distinct virulence and diseases in humans. Thus, the current multi-omics data provide new insights into the evolution and fitness of SFG virulence and pathogenicity, and intracellular pathogenic bacteria.
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Affiliation(s)
- Khalid El Karkouri
- Unité de Recherche en Maladies Infectieuses et Tropicales Emergentes, UM63, Centre National De La Recherche Scientifique 7278, IRD 198, Institut National De La Santé Et De La Recherche Médicale U1095, Institut Hospitalo-Universitaire Méditerranée-Infection, Aix-Marseille UniversitéMarseille, France
| | - Malgorzata Kowalczewska
- Unité de Recherche en Maladies Infectieuses et Tropicales Emergentes, UM63, Centre National De La Recherche Scientifique 7278, IRD 198, Institut National De La Santé Et De La Recherche Médicale U1095, Institut Hospitalo-Universitaire Méditerranée-Infection, Aix-Marseille UniversitéMarseille, France
| | - Nicholas Armstrong
- Unité de Recherche en Maladies Infectieuses et Tropicales Emergentes, UM63, Centre National De La Recherche Scientifique 7278, IRD 198, Institut National De La Santé Et De La Recherche Médicale U1095, Institut Hospitalo-Universitaire Méditerranée-Infection, Aix-Marseille UniversitéMarseille, France
| | - Said Azza
- Unité de Recherche en Maladies Infectieuses et Tropicales Emergentes, UM63, Centre National De La Recherche Scientifique 7278, IRD 198, Institut National De La Santé Et De La Recherche Médicale U1095, Institut Hospitalo-Universitaire Méditerranée-Infection, Aix-Marseille UniversitéMarseille, France
| | - Pierre-Edouard Fournier
- Unité de Recherche en Maladies Infectieuses et Tropicales Emergentes, UM63, Centre National De La Recherche Scientifique 7278, IRD 198, Institut National De La Santé Et De La Recherche Médicale U1095, Institut Hospitalo-Universitaire Méditerranée-Infection, Aix-Marseille UniversitéMarseille, France
| | - Didier Raoult
- Unité de Recherche en Maladies Infectieuses et Tropicales Emergentes, UM63, Centre National De La Recherche Scientifique 7278, IRD 198, Institut National De La Santé Et De La Recherche Médicale U1095, Institut Hospitalo-Universitaire Méditerranée-Infection, Aix-Marseille UniversitéMarseille, France
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Eldin C, Mélenotte C, Mediannikov O, Ghigo E, Million M, Edouard S, Mege JL, Maurin M, Raoult D. From Q Fever to Coxiella burnetii Infection: a Paradigm Change. Clin Microbiol Rev 2017; 30:115-190. [PMID: 27856520 PMCID: PMC5217791 DOI: 10.1128/cmr.00045-16] [Citation(s) in RCA: 523] [Impact Index Per Article: 74.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Coxiella burnetii is the agent of Q fever, or "query fever," a zoonosis first described in Australia in 1937. Since this first description, knowledge about this pathogen and its associated infections has increased dramatically. We review here all the progress made over the last 20 years on this topic. C. burnetii is classically a strict intracellular, Gram-negative bacterium. However, a major step in the characterization of this pathogen was achieved by the establishment of its axenic culture. C. burnetii infects a wide range of animals, from arthropods to humans. The genetic determinants of virulence are now better known, thanks to the achievement of determining the genome sequences of several strains of this species and comparative genomic analyses. Q fever can be found worldwide, but the epidemiological features of this disease vary according to the geographic area considered, including situations where it is endemic or hyperendemic, and the occurrence of large epidemic outbreaks. In recent years, a major breakthrough in the understanding of the natural history of human infection with C. burnetii was the breaking of the old dichotomy between "acute" and "chronic" Q fever. The clinical presentation of C. burnetii infection depends on both the virulence of the infecting C. burnetii strain and specific risks factors in the infected patient. Moreover, no persistent infection can exist without a focus of infection. This paradigm change should allow better diagnosis and management of primary infection and long-term complications in patients with C. burnetii infection.
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Affiliation(s)
- Carole Eldin
- URMITE, UMR CNRS 7278, IRD 198, INSERM U1095, Faculté de Médecine, Marseille, France
| | - Cléa Mélenotte
- URMITE, UMR CNRS 7278, IRD 198, INSERM U1095, Faculté de Médecine, Marseille, France
| | - Oleg Mediannikov
- URMITE, UMR CNRS 7278, IRD 198, INSERM U1095, Faculté de Médecine, Marseille, France
| | - Eric Ghigo
- URMITE, UMR CNRS 7278, IRD 198, INSERM U1095, Faculté de Médecine, Marseille, France
| | - Matthieu Million
- URMITE, UMR CNRS 7278, IRD 198, INSERM U1095, Faculté de Médecine, Marseille, France
| | - Sophie Edouard
- URMITE, UMR CNRS 7278, IRD 198, INSERM U1095, Faculté de Médecine, Marseille, France
| | - Jean-Louis Mege
- URMITE, UMR CNRS 7278, IRD 198, INSERM U1095, Faculté de Médecine, Marseille, France
| | - Max Maurin
- Institut de Biologie et de Pathologie, CHU de Grenoble, Grenoble, France
| | - Didier Raoult
- URMITE, UMR CNRS 7278, IRD 198, INSERM U1095, Faculté de Médecine, Marseille, France
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Single sample resolution of rare microbial dark matter in a marine invertebrate metagenome. Sci Rep 2016; 6:34362. [PMID: 27681823 PMCID: PMC5041132 DOI: 10.1038/srep34362] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 09/13/2016] [Indexed: 12/31/2022] Open
Abstract
Direct, untargeted sequencing of environmental samples (metagenomics) and de novo genome assembly enable the study of uncultured and phylogenetically divergent organisms. However, separating individual genomes from a mixed community has often relied on the differential-coverage analysis of multiple, deeply sequenced samples. In the metagenomic investigation of the marine bryozoan Bugula neritina, we uncovered seven bacterial genomes associated with a single B. neritina individual that appeared to be transient associates, two of which were unique to one individual and undetectable using certain “universal” 16S rRNA primers and probes. We recovered high quality genome assemblies for several rare instances of “microbial dark matter,” or phylogenetically divergent bacteria lacking genomes in reference databases, from a single tissue sample that was not subjected to any physical or chemical pre-treatment. One of these rare, divergent organisms has a small (593 kbp), poorly annotated genome with low GC content (20.9%) and a 16S rRNA gene with just 65% sequence similarity to the closest reference sequence. Our findings illustrate the importance of sampling strategy and de novo assembly of metagenomic reads to understand the extent and function of bacterial biodiversity.
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Zhu DT, Xia WQ, Rao Q, Liu SS, Ghanim M, Wang XW. Sequencing and comparison of the Rickettsia genomes from the whitefly Bemisia tabaci Middle East Asia Minor I. INSECT SCIENCE 2016; 23:531-542. [PMID: 27273750 DOI: 10.1111/1744-7917.12367] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/01/2016] [Indexed: 06/06/2023]
Abstract
The whitefly, Bemisia tabaci, harbors the primary symbiont 'Candidatus Portiera aleyrodidarum' and a variety of secondary symbionts. Among these secondary symbionts, Rickettsia is the only one that can be detected both inside and outside the bacteriomes. Infection with Rickettsia has been reported to influence several aspects of the whitefly biology, such as fitness, sex ratio, virus transmission and resistance to pesticides. However, mechanisms underlying these differences remain unclear, largely due to the lack of genomic information of Rickettsia. In this study, we sequenced the genome of two Rickettsia strains isolated from the Middle East Asia Minor 1 (MEAM1) species of the B. tabaci complex in China and Israel. Both Rickettsia genomes were of high coding density and AT-rich, containing more than 1000 coding sequences, much larger than that of the coexisted primary symbiont, Portiera. Moreover, the two Rickettsia strains isolated from China and Israel shared most of the genes with 100% identity and only nine genes showed sequence differences. The phylogenetic analysis using orthologs shared in the genus, inferred the proximity of Rickettsia in MEAM1 and Rickettsia bellii. Functional analysis revealed that Rickettsia was unable to synthesize amino acids required for complementing the whitefly nutrition. Besides, a type IV secretion system and a number of virulence-related genes were detected in the Rickettsia genome. The presence of virulence-related genes might benefit the symbiotic life of the bacteria, and hint on potential effects of Rickettsia on whiteflies. The genome sequences of Rickettsia provided a basis for further understanding the function of Rickettsia in whiteflies.
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Affiliation(s)
- Dan-Tong Zhu
- Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Wen-Qiang Xia
- Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Qiong Rao
- School of Agriculture and Food Science, Zhejiang Agriculture and Forestry University, Lin'an, Hangzhou, China
| | - Shu-Sheng Liu
- Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Murad Ghanim
- Department of Entomology, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
| | - Xiao-Wei Wang
- Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
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Kimita G, Mutai B, Nyanjom SG, Wamunyokoli F, Waitumbi J. Phylogenetic Variants of Rickettsia africae, and Incidental Identification of "Candidatus Rickettsia Moyalensis" in Kenya. PLoS Negl Trop Dis 2016; 10:e0004788. [PMID: 27387337 PMCID: PMC4936727 DOI: 10.1371/journal.pntd.0004788] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 05/29/2016] [Indexed: 11/18/2022] Open
Abstract
Background Rickettsia africae, the etiological agent of African tick bite fever, is widely distributed in sub-Saharan Africa. Contrary to reports of its homogeneity, a localized study in Asembo, Kenya recently reported high genetic diversity. The present study aims to elucidate the extent of this heterogeneity by examining archived Rickettsia africae DNA samples collected from different eco-regions of Kenya. Methods To evaluate their phylogenetic relationships, archived genomic DNA obtained from 57 ticks a priori identified to contain R. africae by comparison to ompA, ompB and gltA genes was used to amplify five rickettsial genes i.e. gltA, ompA, ompB, 17kDa and sca4. The resulting amplicons were sequenced. Translated amino acid alignments were used to guide the nucleotide alignments. Single gene and concatenated alignments were used to infer phylogenetic relationships. Results Out of the 57 DNA samples, three were determined to be R. aeschlimanii and not R. africae. One sample turned out to be a novel rickettsiae and an interim name of “Candidatus Rickettsia moyalensis” is proposed. The bonafide R. africae formed two distinct clades. Clade I contained 9% of the samples and branched with the validated R. africae str ESF-5, while clade II (two samples) formed a distinct sub-lineage. Conclusions This data supports the use of multiple genes for phylogenetic inferences. It is determined that, despite its recent emergence, the R. africae lineage is diverse. This data also provides evidence of a novel Rickettsia species, Candidatus Rickettsia moyalensis. Rickettsia africae is a bacterium mainly vectored by Amblyomma and Rhipicephalus species of ticks. It is the etiological agent of African tick bite fever (ATBF), a spotted fever rickettsiosis that presents as an acute febrile illness characterized by petecheal skin hemorrhages, from which the name is derived. This bacterium is probably the most important in sub-Saharan Africa, including Kenya, in terms of incidence and prevalence. This notwithstanding, the disease is poorly understood and is often mistreated as malaria, and therefore qualifies as a highly neglected disease. This study examined the genetic relationships of R. africae collected from diverse eco-regions of Kenya. We present data that indicate high genetic diversity in Kenya’s R. africae and corroborate a recent study that reported similar genetic diversity in R. africae samples collected from a localized area in western Kenya. Importantly, we describe a divergent lineage and propose the name Candidatus Rickettsia moyalensis.
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Affiliation(s)
- Gathii Kimita
- Walter Reed Project/ Kenya Medical Research Institute, Kisumu, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Juja, Kenya
| | - Beth Mutai
- Walter Reed Project/ Kenya Medical Research Institute, Kisumu, Kenya
| | - Steven Ger Nyanjom
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Juja, Kenya
| | - Fred Wamunyokoli
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Juja, Kenya
| | - John Waitumbi
- Walter Reed Project/ Kenya Medical Research Institute, Kisumu, Kenya
- * E-mail:
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Schroeder CLC, Narra HP, Sahni A, Rojas M, Khanipov K, Patel J, Shah R, Fofanov Y, Sahni SK. Identification and Characterization of Novel Small RNAs in Rickettsia prowazekii. Front Microbiol 2016; 7:859. [PMID: 27375581 PMCID: PMC4896933 DOI: 10.3389/fmicb.2016.00859] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 05/23/2016] [Indexed: 12/12/2022] Open
Abstract
Emerging evidence implicates a critically important role for bacterial small RNAs (sRNAs) as post-transcriptional regulators of physiology, metabolism, stress/adaptive responses, and virulence, but the roles of sRNAs in pathogenic Rickettsia species remain poorly understood. Here, we report on the identification of both novel and well-known bacterial sRNAs in Rickettsia prowazekii, known to cause epidemic typhus in humans. RNA sequencing of human microvascular endothelial cells (HMECs), the preferred targets during human rickettsioses, infected with R. prowazekii revealed the presence of 35 trans-acting and 23 cis-acting sRNAs, respectively. Of these, expression of two trans-acting (Rp_sR17 and Rp_sR60) and one cis-acting (Rp_sR47) novel sRNAs and four well-characterized bacterial sRNAs (RNaseP_bact_a, α-tmRNA, 4.5S RNA, 6S RNA) was further confirmed by Northern blot or RT-PCR analyses. The transcriptional start sites of five novel rickettsial sRNAs and 6S RNA were next determined using 5' RLM-RACE yielding evidence for their independent biogenesis in R. prowazekii. Finally, computational approaches were employed to determine the secondary structures and potential mRNA targets of novel sRNAs. Together, these results establish the presence and expression of sRNAs in R. prowazekii during host cell infection and suggest potential functional roles for these important post-transcriptional regulators in rickettsial biology and pathogenesis.
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Affiliation(s)
| | - Hema P. Narra
- Department of Pathology, University of Texas Medical BranchGalveston, TX, USA
| | - Abha Sahni
- Department of Pathology, University of Texas Medical BranchGalveston, TX, USA
| | - Mark Rojas
- Department of Pharmacology, University of Texas Medical BranchGalveston, TX, USA
| | - Kamil Khanipov
- Department of Pharmacology, University of Texas Medical BranchGalveston, TX, USA
| | - Jignesh Patel
- Department of Pathology, University of Texas Medical BranchGalveston, TX, USA
| | - Riya Shah
- Department of Neuroscience, University of Texas at DallasDallas, TX, USA
| | - Yuriy Fofanov
- Department of Pharmacology, University of Texas Medical BranchGalveston, TX, USA
| | - Sanjeev K. Sahni
- Department of Pathology, University of Texas Medical BranchGalveston, TX, USA
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Bakour S, Sankar SA, Rathored J, Biagini P, Raoult D, Fournier PE. Identification of virulence factors and antibiotic resistance markers using bacterial genomics. Future Microbiol 2016; 11:455-66. [PMID: 26974504 DOI: 10.2217/fmb.15.149] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In recent years, the number of multidrug-resistant bacteria has increased rapidly and several epidemics were signaled in different regions of the world. Faced with this situation that presents a major global public health concern, the development and the use of new and rapid technologies is more than urgent. The use of the next-generation sequencing platforms by microbiologists and infectious disease specialists has allowed great progress in the medical field. Here, we review the usefulness of whole-genome sequencing for the detection of virulence and antibiotic resistance associated genes.
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Affiliation(s)
- Sofiane Bakour
- Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), UM 63, CNRS 7278, IRD 198, INSERM 1095, IHU Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille-Université, Marseille, France
| | - Senthil Alias Sankar
- Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), UM 63, CNRS 7278, IRD 198, INSERM 1095, IHU Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille-Université, Marseille, France
| | - Jaishriram Rathored
- Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), UM 63, CNRS 7278, IRD 198, INSERM 1095, IHU Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille-Université, Marseille, France
| | - Philippe Biagini
- UMR CNRS 7268 Equipe "Emergence et coévolution virale," Etablissement Français du Sang Alpes-Méditerranée et Aix-Marseille Université, 27 Boulevard Jean Moulin, 13005 Marseille
| | - Didier Raoult
- Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), UM 63, CNRS 7278, IRD 198, INSERM 1095, IHU Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille-Université, Marseille, France
| | - Pierre-Edouard Fournier
- Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), UM 63, CNRS 7278, IRD 198, INSERM 1095, IHU Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille-Université, Marseille, France
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El Karkouri K, Pontarotti P, Raoult D, Fournier PE. Origin and Evolution of Rickettsial Plasmids. PLoS One 2016; 11:e0147492. [PMID: 26866478 PMCID: PMC4750851 DOI: 10.1371/journal.pone.0147492] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 01/05/2016] [Indexed: 11/21/2022] Open
Abstract
Background Rickettsia species are strictly intracellular bacteria that have undergone a reductive genomic evolution. Despite their allopatric lifestyle, almost half of the 26 currently validated Rickettsia species have plasmids. In order to study the origin, evolutionary history and putative roles of rickettsial plasmids, we investigated the evolutionary processes that have shaped 20 plasmids belonging to 11 species, using comparative genomics and phylogenetic analysis between rickettsial, microbial and non-microbial genomes. Results Plasmids were differentially present among Rickettsia species. The 11 species had 1 to 4 plasmid (s) with a size ranging from 12 kb to 83 kb. We reconstructed pRICO, the last common ancestor of the current rickettsial plasmids. pRICO was vertically inherited mainly from Rickettsia/Orientia chromosomes and diverged vertically into a single or multiple plasmid(s) in each species. These plasmids also underwent a reductive evolution by progressive gene loss, similar to that observed in rickettsial chromosomes, possibly leading to cryptic plasmids or complete plasmid loss. Moreover, rickettsial plasmids exhibited ORFans, recent gene duplications and evidence of horizontal gene transfer events with rickettsial and non-rickettsial genomes mainly from the α/γ-proteobacteria lineages. Genes related to maintenance and plasticity of plasmids, and to adaptation and resistance to stress mostly evolved under vertical and/or horizontal processes. Those involved in nucleotide/carbohydrate transport and metabolism were under the influence of vertical evolution only, whereas genes involved in cell wall/membrane/envelope biogenesis, cycle control, amino acid/lipid/coenzyme and secondary metabolites biosynthesis, transport and metabolism underwent mainly horizontal transfer events. Conclusion Rickettsial plasmids had a complex evolution, starting with a vertical inheritance followed by a reductive evolution associated with increased complexity via horizontal gene transfer as well as gene duplication and genesis. The plasmids are plastic and mosaic structures that may play biological roles similar to or distinct from their co-residing chromosomes in an obligate intracellular lifestyle.
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Affiliation(s)
- Khalid El Karkouri
- Unité de Recherche en Maladies Infectieuses et Tropicales Emergentes (URMITE), UM63, CNRS7278, IRD198, INSERMU1095, Institut Hospitalo-Universitaire Méditerranée-Infection, Aix-Marseille Université, Faculté de Médecine, 27 boulevard Jean Moulin, 13385 Marseille cedex 5, France
| | - Pierre Pontarotti
- Aix Marseille Université, CNRS, Centrale Marseille, I2M UMR 7373, Equipe Evolution Biologique et Modélisation, Marseille, France
| | - Didier Raoult
- Unité de Recherche en Maladies Infectieuses et Tropicales Emergentes (URMITE), UM63, CNRS7278, IRD198, INSERMU1095, Institut Hospitalo-Universitaire Méditerranée-Infection, Aix-Marseille Université, Faculté de Médecine, 27 boulevard Jean Moulin, 13385 Marseille cedex 5, France
| | - Pierre-Edouard Fournier
- Unité de Recherche en Maladies Infectieuses et Tropicales Emergentes (URMITE), UM63, CNRS7278, IRD198, INSERMU1095, Institut Hospitalo-Universitaire Méditerranée-Infection, Aix-Marseille Université, Faculté de Médecine, 27 boulevard Jean Moulin, 13385 Marseille cedex 5, France
- * E-mail:
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D’Amato F, Eldin C, Raoult D. The contribution of genomics to the study of Q fever. Future Microbiol 2016; 11:253-72. [DOI: 10.2217/fmb.15.137] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Coxiella burnetii is the etiological agent of Q fever, a worldwide zoonosis that can result in large outbreaks. The birth of genomics and sequencing of C. burnetii strains has revolutionized many fields of study of this infection. Accurate genotyping methods and comparative genomic analysis have enabled description of the diversity of strains around the world and their link with pathogenicity. Genomics has also permitted the development of qPCR tools and axenic culture medium, facilitating the diagnosis of Q fever. Moreover, several pathophysiological mechanisms can now be predicted and therapeutic strategies can be determined thanks to in silico genome analysis. An extensive pan-genomic analysis will allow for a comprehensive view of the clonal diversity of C. burnetii and its link with virulence.
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Affiliation(s)
- Felicetta D’Amato
- Aix-Marseille Université, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, UM63, CNRS 7278, IRD 198, INSERM 1095, Marseille, France
| | - Carole Eldin
- Aix-Marseille Université, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, UM63, CNRS 7278, IRD 198, INSERM 1095, Marseille, France
| | - Didier Raoult
- Aix-Marseille Université, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, UM63, CNRS 7278, IRD 198, INSERM 1095, Marseille, France
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Comparative Proteomic Profiling of Ehrlichia ruminantium Pathogenic Strain and Its High-Passaged Attenuated Strain Reveals Virulence and Attenuation-Associated Proteins. PLoS One 2015; 10:e0145328. [PMID: 26691135 PMCID: PMC4686967 DOI: 10.1371/journal.pone.0145328] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 12/01/2015] [Indexed: 11/19/2022] Open
Abstract
The obligate intracellular bacterium Ehrlichia ruminantium (ER) causes heartwater, a fatal tick-borne disease in livestock. In the field, ER strains present different levels of virulence, limiting vaccine efficacy, for which the molecular basis remains unknown. Moreover, there are no genetic tools currently available for ER manipulation, thus limiting the knowledge of the genes/proteins that are essential for ER pathogenesis and biology. As such, to identify proteins and/or mechanisms involved in ER virulence, we performed the first exhaustive comparative proteomic analysis between a virulent strain (ERGvir) and its high-passaged attenuated strain (ERGatt). Despite their different behaviors in vivo and in vitro, our results from 1DE-nanoLC-MS/MS showed that ERGvir and ERGatt share 80% of their proteins; this core proteome includes chaperones, proteins involved in metabolism, protein-DNA-RNA biosynthesis and processing, and bacterial effectors. Conventional 2DE revealed that 85% of the identified proteins are proteoforms, suggesting that post-translational modifications (namely glycosylation) are important in ER biology. Strain-specific proteins were also identified: while ERGatt has an increased number and overexpression of proteins involved in cell division, metabolism, transport and protein processing, ERGvir shows an overexpression of proteins and proteoforms (DIGE experiments) involved in pathogenesis such as Lpd, AnkA, VirB9 and B10, providing molecular evidence for its increased virulence in vivo and in vitro. Overall, our work reveals that ERGvir and ERGatt proteomes are streamlined to fulfill their biological function (maximum virulence for ERGvir and replicative capacity for ERGatt), and we provide both pioneering data and novel insights into the pathogenesis of this obligate intracellular bacterium.
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Schroeder CLC, Narra HP, Rojas M, Sahni A, Patel J, Khanipov K, Wood TG, Fofanov Y, Sahni SK. Bacterial small RNAs in the Genus Rickettsia. BMC Genomics 2015; 16:1075. [PMID: 26679185 PMCID: PMC4683814 DOI: 10.1186/s12864-015-2293-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 12/14/2015] [Indexed: 01/02/2023] Open
Abstract
Background Rickettsia species are obligate intracellular Gram-negative pathogenic bacteria and the etiologic agents of diseases such as Rocky Mountain spotted fever (RMSF), Mediterranean spotted fever, epidemic typhus, and murine typhus. Genome sequencing revealed that R. prowazekii has ~25 % non-coding DNA, the majority of which is thought to be either “junk DNA” or pseudogenes resulting from genomic reduction. These characteristics also define other Rickettsia genomes. Bacterial small RNAs, whose biogenesis is predominantly attributed to either the intergenic regions (trans-acting) or to the antisense strand of an open reading frame (cis-acting), are now appreciated to be among the most important post-transcriptional regulators of bacterial virulence and growth. We hypothesize that intergenic regions in rickettsial species encode for small, non-coding RNAs (sRNAs) involved in the regulation of its transcriptome, leading to altered virulence and adaptation depending on the host niche. Results We employed a combination of bioinformatics and in vitro approaches to explore the presence of sRNAs in a number of species within Genus Rickettsia. Using the sRNA Identification Protocol using High-throughput Technology (SIPHT) web interface, we predicted over 1,700 small RNAs present in the intergenic regions of 16 different strains representing 13 rickettsial species. We further characterized novel sRNAs from typhus (R. prowazekii and R. typhi) and spotted fever (R. rickettsii and R. conorii) groups for their promoters and Rho-independent terminators using Bacterial Promoter Prediction Program (BPROM) and TransTermHP prediction algorithms, respectively. Strong σ70 promoters were predicted upstream of all novel small RNAs, indicating the potential for transcriptional activity. Next, we infected human microvascular endothelial cells (HMECs) with R. prowazekii for 3 h and 24 h and performed Next Generation Sequencing to experimentally validate the expression of 26 sRNA candidates predicted in R. prowazekii. Reverse transcriptase PCR was also used to further verify the expression of six putative novel sRNA candidates in R. prowazekii. Conclusions Our results yield clear evidence for the expression of novel R. prowazekii sRNA candidates during infection of HMECs. This is the first description of novel small RNAs for a highly pathogenic species of Rickettsia, which should lead to new insights into rickettsial virulence and adaptation mechanisms. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-2293-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Casey L C Schroeder
- Department of Pathology, the University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555, USA.
| | - Hema P Narra
- Department of Pathology, the University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555, USA.
| | - Mark Rojas
- Department of Pharmacology, the University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555, USA.
| | - Abha Sahni
- Department of Pathology, the University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555, USA.
| | - Jignesh Patel
- Department of Pathology, the University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555, USA.
| | - Kamil Khanipov
- Department of Pharmacology, the University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555, USA.
| | - Thomas G Wood
- Department of Biochemistry and Molecular Biology, the University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555, USA.
| | - Yuriy Fofanov
- Department of Pharmacology, the University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555, USA.
| | - Sanjeev K Sahni
- Department of Pathology, the University of Texas Medical Branch, 301 University Blvd, Galveston, TX, 77555, USA.
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Travers MA, Boettcher Miller K, Roque A, Friedman CS. Bacterial diseases in marine bivalves. J Invertebr Pathol 2015. [DOI: 10.1016/j.jip.2015.07.010] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Keller C, Krüger A, Schwarz NG, Rakotozandrindrainy R, Rakotondrainiarivelo JP, Razafindrabe T, Derschum H, Silaghi C, Pothmann D, Veit A, Hogan B, May J, Girmann M, Kramme S, Fleischer B, Poppert S. High detection rate of Rickettsia africae in Amblyomma variegatum but low prevalence of anti-rickettsial antibodies in healthy pregnant women in Madagascar. Ticks Tick Borne Dis 2015; 7:60-65. [PMID: 26318262 DOI: 10.1016/j.ttbdis.2015.08.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 05/22/2015] [Accepted: 08/10/2015] [Indexed: 11/29/2022]
Abstract
Tick-borne spotted fever group (SFG) rickettsioses are emerging infectious diseases in Sub-Saharan Africa. In Madagascar, the endemicity of tick-borne rickettsiae and their vectors has been incompletely studied. The first part of the present study was conducted in 2011 and 2012 to identify potential anthropophilic tick vectors for SFG rickettsiae on cattle from seven Malagasy regions, and to detect and characterize rickettsiae in these ticks. Amblyomma variegatum was the only anthropophilic tick species found on 262 cattle. Using a novel ompB-specific qPCR, screening for rickettsial DNA was performed on 111 A. variegatum ticks. Rickettsial DNA was detected in 96 of 111 ticks studied (86.5%). Rickettsia africae was identified as the only infecting rickettsia using phylogenetic analysis of ompA and ompB gene sequences and three variable intergenic spacers from 11 ticks. The second part of the study was a cross-sectional survey for antibodies against SFG rickettsiae in plasma samples taken from healthy, pregnant women at six locations in Madagascar, two at sea level and four between 450 and 1300m altitude. An indirect fluorescent antibody test with Rickettsia conorii as surrogate SFG rickettsial antigen was used. We found R. conorii-seropositives at all altitudes with prevalences between 0.5% and 3.1%. Our results suggest that A. variegatum ticks highly infected with R. africae are the most prevalent cattle-associated tick vectors for SFG rickettsiosis in Madagascar. Transmission of SFG rickettsiosis to humans occurs at different altitudes in Madagascar and should be considered as a relevant cause of febrile diseases.
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Affiliation(s)
- Christian Keller
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany; Institute for Virology, Philipps University, Marburg, Germany.
| | | | | | | | | | | | | | - Cornelia Silaghi
- Comparative Tropical Medicine and Parasitology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Daniela Pothmann
- Comparative Tropical Medicine and Parasitology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Alexandra Veit
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Benedikt Hogan
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Jürgen May
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Mirko Girmann
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Stefanie Kramme
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | | | - Sven Poppert
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany; Institute for Medical Microbiology, Justus Liebig University, Giessen, Germany
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Loss of TSS1 in hypervirulent Coxiella burnetii 175, the causative agent of Q fever in French Guiana. Comp Immunol Microbiol Infect Dis 2015; 41:35-41. [DOI: 10.1016/j.cimid.2015.04.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 04/23/2015] [Accepted: 04/28/2015] [Indexed: 11/17/2022]
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Targeted knockout of the Rickettsia rickettsii OmpA surface antigen does not diminish virulence in a mammalian model system. mBio 2015; 6:mBio.00323-15. [PMID: 25827414 PMCID: PMC4453529 DOI: 10.1128/mbio.00323-15] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Strains of Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever (RMSF), differ dramatically in virulence despite >99% genetic homology. Spotted fever group (SFG) rickettsiae produce two immunodominant outer membrane proteins, rickettsial OmpA (rOmpA) and rOmpB, which are conserved throughout the SFG and thought to be fundamental to pathogenesis. rOmpA is present in all virulent strains of R. rickettsii but is not produced in the only documented avirulent strain, Iowa, due to a premature stop codon. Here we report the creation of an isogenic ompA mutant in the highly virulent strain Sheila Smith by insertion of intronic RNA to create a premature stop codon 312 bp downstream of the 6,747-bp open reading frame initiation site (int312). Targeted insertion was accomplished using an LtrA group II intron retrohoming system. Growth and entry rates of Sheila Smith ompA::int312 in Vero cells remained comparable to those of the wild type. Virulence was assessed in a guinea pig model by challenge with 100 PFU of either ompA::int312 Sheila Smith or the wild type, but no significant difference in either fever peak (40.5°C) or duration (8 days) were shown between the wild type and the knockout. The ability to disrupt genes in a site-specific manner using an LtrA group II intron system provides an important new tool for evaluation of potential virulence determinants in rickettsial disease research. R. rickettsii rOmpA is an immunodominant outer membrane autotransporter conserved in the spotted fever group. Previous studies and genomic comparisons suggest that rOmpA is involved in adhesion and may be critical for virulence. Little information is available for rickettsial virulence factors in an isogenic background, as limited systems for targeted gene disruption are currently available. Here we describe the creation of an rOmpA knockout by insertion of a premature stop codon into the 5′ end of the open reading frame using a group II intron system. An isogenic rOmpA knockout mutation in the highly virulent Sheila Smith strain did not cause attenuation in a guinea pig model of infection, and no altered phenotype was observed in cell culture. We conclude that rOmpA is not critical for virulence in a guinea pig model but may play a role in survival or transmission from the tick vector.
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Pagnier I, Yutin N, Croce O, Makarova KS, Wolf YI, Benamar S, Raoult D, Koonin EV, La Scola B. Babela massiliensis, a representative of a widespread bacterial phylum with unusual adaptations to parasitism in amoebae. Biol Direct 2015; 10:13. [PMID: 25884386 PMCID: PMC4378268 DOI: 10.1186/s13062-015-0043-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 02/12/2015] [Indexed: 11/24/2022] Open
Abstract
Background Only a small fraction of bacteria and archaea that are identifiable by metagenomics can be grown on standard media. Recent efforts on deep metagenomics sequencing, single-cell genomics and the use of specialized culture conditions (culturomics) increasingly yield novel microbes some of which represent previously uncharacterized phyla and possess unusual biological traits. Results We report isolation and genome analysis of Babela massiliensis, an obligate intracellular parasite of Acanthamoeba castellanii. B. massiliensis shows an unusual, fission mode of cell multiplication whereby large, polymorphic bodies accumulate in the cytoplasm of infected amoeba and then split into mature bacterial cells. This unique mechanism of cell division is associated with a deep degradation of the cell division machinery and delayed expression of the ftsZ gene. The genome of B. massiliensis consists of a circular chromosome approximately 1.12 megabase in size that encodes, 981 predicted proteins, 38 tRNAs and one typical rRNA operon. Phylogenetic analysis shows that B. massiliensis belongs to the putative bacterial phylum TM6 that so far was represented by the draft genome of the JCVI TM6SC1 bacterium obtained by single cell genomics and numerous environmental sequences. Conclusions Currently, B. massiliensis is the only cultivated member of the putative TM6 phylum. Phylogenomic analysis shows diverse taxonomic affinities for B. massiliensis genes, suggestive of multiple gene acquisitions via horizontal transfer from other bacteria and eukaryotes. Horizontal gene transfer is likely to be facilitated by the cohabitation of diverse parasites and symbionts inside amoeba. B. massiliensis encompasses many genes encoding proteins implicated in parasite-host interaction including the greatest number of ankyrin repeats among sequenced bacteria and diverse proteins related to the ubiquitin system. Characterization of B. massiliensis, a representative of a distinct bacterial phylum, thanks to its ability to grow in amoeba, reaffirms the critical role of diverse culture approaches in microbiology. Reviewers This article was reviewed by Dr. Igor Zhulin, Dr. Jeremy Selengut, and Pr Martijn Huynen. Electronic supplementary material The online version of this article (doi:10.1186/s13062-015-0043-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Isabelle Pagnier
- URMITE, CNRS UMR IRD 6236, Faculté de Médecine, Université de la Méditerranée, 27 Bd. Jean Moulin, 13385, Marseille Cedex 5, France.
| | - Natalya Yutin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, 20894, USA.
| | - Olivier Croce
- URMITE, CNRS UMR IRD 6236, Faculté de Médecine, Université de la Méditerranée, 27 Bd. Jean Moulin, 13385, Marseille Cedex 5, France.
| | - Kira S Makarova
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, 20894, USA.
| | - Yuri I Wolf
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, 20894, USA.
| | - Samia Benamar
- URMITE, CNRS UMR IRD 6236, Faculté de Médecine, Université de la Méditerranée, 27 Bd. Jean Moulin, 13385, Marseille Cedex 5, France.
| | - Didier Raoult
- URMITE, CNRS UMR IRD 6236, Faculté de Médecine, Université de la Méditerranée, 27 Bd. Jean Moulin, 13385, Marseille Cedex 5, France.
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, 20894, USA.
| | - Bernard La Scola
- URMITE, CNRS UMR IRD 6236, Faculté de Médecine, Université de la Méditerranée, 27 Bd. Jean Moulin, 13385, Marseille Cedex 5, France.
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Fournier PE, Dubourg G, Raoult D. Clinical detection and characterization of bacterial pathogens in the genomics era. Genome Med 2014; 6:114. [PMID: 25593594 PMCID: PMC4295418 DOI: 10.1186/s13073-014-0114-2] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The availability of genome sequences obtained using next-generation sequencing (NGS) has revolutionized the field of infectious diseases. Indeed, more than 38,000 bacterial and 5,000 viral genomes have been sequenced to date, including representatives of all significant human pathogens. These tremendous amounts of data have not only enabled advances in fundamental biology, helping to understand the pathogenesis of microorganisms and their genomic evolution, but have also had implications for clinical microbiology. Here, we first review the current achievements of genomics in the development of improved diagnostic tools, including those that are now available in the clinic, such as the design of PCR assays for the detection of microbial pathogens, virulence factors or antibiotic-resistance determinants, or the design of optimized culture media for 'unculturable' pathogens. We then review the applications of genomics to the investigation of outbreaks, either through the design of genotyping assays or the direct sequencing of the causative strains. Finally, we discuss how genomics might change clinical microbiology in the future.
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Affiliation(s)
- Pierre-Edouard Fournier
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, UM63, CNRS7278, IRD198, InsermU1095, Institut hospitalo-universitaire Méditerranée-Infection, Aix-Marseille University, Faculté de Medecine, 27 Blvd Jean Moulin, Marseille, 13385, cedex 5 France
| | - Gregory Dubourg
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, UM63, CNRS7278, IRD198, InsermU1095, Institut hospitalo-universitaire Méditerranée-Infection, Aix-Marseille University, Faculté de Medecine, 27 Blvd Jean Moulin, Marseille, 13385, cedex 5 France
| | - Didier Raoult
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, UM63, CNRS7278, IRD198, InsermU1095, Institut hospitalo-universitaire Méditerranée-Infection, Aix-Marseille University, Faculté de Medecine, 27 Blvd Jean Moulin, Marseille, 13385, cedex 5 France
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Yssouf A, Socolovschi C, Kernif T, Temmam S, Lagadec E, Tortosa P, Parola P. First molecular detection of Rickettsia africae in ticks from the Union of the Comoros. Parasit Vectors 2014; 7:444. [PMID: 25245895 PMCID: PMC4289259 DOI: 10.1186/1756-3305-7-444] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 09/09/2014] [Indexed: 11/22/2022] Open
Abstract
Background Rickettsia africae is the agent of African tick bite fever, a disease transmitted by ticks in sub-Saharan Africa. In Union of the Comoros, a recent study reported the presence of a Rickettsia africae vector but no information has been provided on the circulation of the pathogenic agent in this country. Methods To evaluate the possible circulation of Rickettsia spp. in Comorian cattle, genomic DNA was extracted from 512 ticks collected either in the Union of the Comoros or from animals imported from Tanzania and subsequently tested for Rickettsia infection by quantitative PCR. Results Rickettsia africae was detected in 90% (60/67) of Amblyomma variegatum, 1% (1/92) of Rhipicephalus appendiculatus and 2.7% (8/296) of Rhipicephalus (Boophilus) microplus ticks collected in the Union of the Comoros, as well as in 77.14% (27/35) of Amblyomma variegatum ticks collected from imported cattle. Partial sequences of both bacterial gltA and ompA genes were used in a phylogenetic analysis revealing the presence of several haplotypes, all included within the Rickettsia africae clade. Conclusions Our study reports the first evidence of Rickettsia africae in ticks collected from the Union of the Comoros. The data show a significant difference of infection rate of Rickettsia africae infected ticks between the Islands, with maximum rates measured in Grande Comore Island, sheltering the main entry port for live animal importation from Tanzania. The high infection levels reported herein indicate the need for an in-depth assessment of the burden of rickettsioses in the Union of the Comoros, especially among those at risk of infection, such as cattle herders.
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Affiliation(s)
| | | | | | | | | | | | - Philippe Parola
- Aix Marseille Université, Unité de Recherche en Maladies Infectieuses et Tropicales Emergentes (URMITE), UM63, CNRS 7278, IRD 198, Inserm 1095, WHO Collaborative Center for Rickettsioses and Other Arthropod-borne Bacterial Diseases, Faculté de Médecine, 27 bd Jean Moulin, 13385 Marseille cedex 5, France.
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Merhej V, Angelakis E, Socolovschi C, Raoult D. Genotyping, evolution and epidemiological findings of Rickettsia species. INFECTION GENETICS AND EVOLUTION 2014; 25:122-37. [DOI: 10.1016/j.meegid.2014.03.014] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 03/10/2014] [Accepted: 03/12/2014] [Indexed: 01/12/2023]
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Duan C, Xiong X, Qi Y, Gong W, Jiao J, Wen B. Genomic and comparative genomic analyses of Rickettsia heilongjiangensis provide insight into its evolution and pathogenesis. INFECTION GENETICS AND EVOLUTION 2014; 26:274-82. [PMID: 24924907 DOI: 10.1016/j.meegid.2014.05.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 05/23/2014] [Accepted: 05/27/2014] [Indexed: 11/28/2022]
Abstract
Rickettsia heilongjiangensis, the causative agent of far eastern spotted fever, is an obligate intracellular gram-negative bacterium that belongs to the spotted fever group rickettsiae. To understand the evolution and pathogenesis of R. heilongjiangensis, we analyzed its genome and compared it with other rickettsial genomes available in GenBank. The R. heilongjiangensis chromosome contains 1333 genes, including 1297 protein coding genes and 36 RNA coding genes. The genome also contains 121 pseudogenes, 54 insertion sequences, and 39 tandem repeats. Sixteen genes encoding the major components of the type IV secretion systems were identified in the R. heilongjiangensis genome. In total, 37 β-barrel outer membrane proteins were predicted in the genome, eight of which have been previously confirmed to be outer membrane proteins. In addition, 266 potential virulence factor genes, seven partially deleted antibiotic resistance genes, and a genomic island were identified in the genome. The codon usage in the genome is compatible with its low GC content, and the amino acid usage shows apparent bias. A comparative genomic analysis showed that R. heilongjiangensis and R. japonica share one unique fragment that may be a target sequence for a diagnostic assay. The orthologs of 37 genes of R. heilongjiangensis were found in pathogenic R. rickettsii str. Sheila Smith but not in non-pathogenic R. rickettsii str. Iowa, which may explain why R. heilongjiangensis is pathogenic. Pan-genome analysis showed that R. heilongjiangensis and 42 other rickettsiae strains share 693 core genes with a pan-genome size of 4837 genes. The pan-genome-based phylogeny showed that R. heilongjiangensis was closely related to R. japonica.
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Affiliation(s)
- Changsong Duan
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
| | - Xiaolu Xiong
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
| | - Yong Qi
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
| | - Wenping Gong
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
| | - Jun Jiao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
| | - Bohai Wen
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
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Sahni SK, Narra HP, Sahni A, Walker DH. Recent molecular insights into rickettsial pathogenesis and immunity. Future Microbiol 2014; 8:1265-88. [PMID: 24059918 DOI: 10.2217/fmb.13.102] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Human infections with arthropod-borne Rickettsia species remain a major global health issue, causing significant morbidity and mortality. Epidemic typhus due to Rickettsia prowazekii has an established reputation as the 'scourge of armies', and as a major determinant of significant 'historical turning points'. No suitable vaccines for human use are currently available to prevent rickettsial diseases. The unique lifestyle features of rickettsiae include obligate intracellular parasitism, intracytoplasmic niche within the host cell, predilection for infection of microvascular endothelium in mammalian hosts, association with arthropods and the tendency for genomic reduction. The fundamental research in the field of Rickettsiology has witnessed significant recent progress in the areas of pathogen adhesion/invasion and host immune responses, as well as the genomics, proteomics, metabolomics, phylogenetics, motility and molecular manipulation of important rickettsial pathogens. The focus of this review article is to capture a snapshot of the latest developments pertaining to the mechanisms of rickettsial pathogenesis and immunity.
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Affiliation(s)
- Sanjeev K Sahni
- Department of Pathology & Institute for Human Infections & Immunity, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555, USA
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Flagellar movement in two bacteria of the family rickettsiaceae: a re-evaluation of motility in an evolutionary perspective. PLoS One 2014; 9:e87718. [PMID: 24505307 PMCID: PMC3914857 DOI: 10.1371/journal.pone.0087718] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 01/02/2014] [Indexed: 01/22/2023] Open
Abstract
Bacteria of the family Rickettsiaceae have always been largely studied not only for their importance in the medical field, but also as model systems in evolutionary biology. In fact, they share a recent common ancestor with mitochondria. The most studied species, belonging to genera Rickettsia and Orientia, are hosted by terrestrial arthropods and include many human pathogens. Nevertheless, recent findings show that a large part of Rickettsiaceae biodiversity actually resides outside the group of well-known pathogenic bacteria. Collecting data on these recently described non-conventional members of the family is crucial in order to gain information on ancestral features of the whole group. Although bacteria of the family Rickettsiaceae, and of the whole order Rickettsiales, are formally described as non-flagellated prokaryotes, some recent findings renewed the debate about this feature. In this paper we report the first finding of members of the family displaying numerous flagella and active movement inside their host cells. These two new taxa are hosted in aquatic environments by protist ciliates and are described here by means of ultrastructural and molecular characterization. Data here reported suggest that the ancestor of Rickettsiales displayed flagellar movement and re-evaluate the hypothesis that motility played a key-role in the origin of mitochondria. Moreover, our study highlights that the aquatic environment represents a well exploited habitat for bacteria of the family Rickettsiaceae. Our results encourage a deep re-consideration of ecological and morphological traits of the family and of the whole order.
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