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Antonopoulos A, Gilleard JS, Charlier J. Next-generation sequencing technologies for helminth diagnostics and surveillance in ruminants: shifting diagnostic barriers. Trends Parasitol 2024:S1471-4922(24)00095-3. [PMID: 38760257 DOI: 10.1016/j.pt.2024.04.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 04/16/2024] [Accepted: 04/17/2024] [Indexed: 05/19/2024]
Abstract
Helminth infections in grazing ruminants are a major issue for livestock farming globally, but are unavoidable in outdoor grazing systems and must be effectively managed to avoid deleterious effects to animal health, and productivity. Next-generation sequencing (NGS) technologies are transforming our understanding of the genetic basis of anthelmintic resistance (AR) and epidemiological studies of ruminant gastrointestinal parasites. They also have the potential to not only help develop and validate molecular diagnostic tests but to be directly used in routine diagnostics integrating species-specific identification and AR into a single test. Here, we review how these developments have opened the pathway for the development of multi-AR and multispecies identification in a single test, with widespread implications for sustainable livestock farming for the future.
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Affiliation(s)
- Alistair Antonopoulos
- Kreavet, Kruibeke, Belgium; School of Biodiversity, One Health, and Veterinary Medicine, University of Glasgow, Glasgow, UK.
| | - John S Gilleard
- Faculty of Veterinary Medicine, Host-Parasite Interactions Program, University of Calgary, Calgary, Alberta, Canada
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2
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Zahid O, Butler M, Hopker A, Freeman E, Costa Júnior LM, Chaudhry U, Sargison N. Nemabiome metabarcoding shows a high prevalence of Haemonchus contortus and predominance of Camelostrongylus mentulatus in alpaca herds in the northern UK. Parasitol Res 2024; 123:201. [PMID: 38698272 PMCID: PMC11065920 DOI: 10.1007/s00436-024-08226-w] [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: 03/02/2024] [Accepted: 04/29/2024] [Indexed: 05/05/2024]
Abstract
Gastrointestinal nematodes (GINs) are a common threat faced by pastoral livestock. Since their major introduction to the UK in the early 1990s, South American camelids have been cograzed with sheep, horses, and other livestock, allowing exposure to a range of GIN species. However, there have been no molecular-based studies to investigate the GIN populations present in these camelids. In the current study, we sampled nine alpaca herds from northern England and southern Scotland and used high-throughput metabarcoded sequencing to describe their GIN species composition. A total of 71 amplicon sequence variants (ASVs) were identified representing eight known GIN species. Haemonchus contortus was the most prevalent species found in almost all herds in significant proportions. The identification of H. contortus in other livestock species is unusual in the northern UK, implying that alpacas may be suitable hosts and potential reservoirs for infection in other hosts. In addition, the camelid-adapted GIN species Camelostrongylus mentulatus was identified predominantly in herds with higher faecal egg counts. These findings highlight the value of applying advanced molecular methods, such as nemabiome metabarcoding to describe the dynamics of gastrointestinal nematode infections in novel situations. The results provide a strong base for further studies involving cograzing animals to confirm the potential role of alpacas in transmitting GIN species between hosts.
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Affiliation(s)
- Osama Zahid
- Royal (Dick) School of Veterinary Studies and Roslin Institute, Easter Bush Veterinary Centre, University of Edinburgh, Midlothian, EH25 9RG, UK.
| | - Meghan Butler
- Royal (Dick) School of Veterinary Studies and Roslin Institute, Easter Bush Veterinary Centre, University of Edinburgh, Midlothian, EH25 9RG, UK
- Current Address: Galedin Veterinary, Kelso, TD5 7BH, UK
| | - Andy Hopker
- Royal (Dick) School of Veterinary Studies and Roslin Institute, Easter Bush Veterinary Centre, University of Edinburgh, Midlothian, EH25 9RG, UK
| | - Emily Freeman
- Royal (Dick) School of Veterinary Studies and Roslin Institute, Easter Bush Veterinary Centre, University of Edinburgh, Midlothian, EH25 9RG, UK
| | - Livio M Costa Júnior
- Pathology Department, Federal University of Maranhão, São Luís, Maranhão, Brazil
| | - Umer Chaudhry
- Royal (Dick) School of Veterinary Studies and Roslin Institute, Easter Bush Veterinary Centre, University of Edinburgh, Midlothian, EH25 9RG, UK
- School of Veterinary Medicine, St. George's University, St. George's Grenada, West Indies, Grenada
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, University of Surrey, Guildford, GU2 7AL, UK
| | - Neil Sargison
- Royal (Dick) School of Veterinary Studies and Roslin Institute, Easter Bush Veterinary Centre, University of Edinburgh, Midlothian, EH25 9RG, UK
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Burden DJ, Bartley DJ, Besier RB, Claerebout E, Elliott TP, Höglund J, Rehbein S, Torres-Acosta JFJ, Van Wyk JA, Yazwinski T. World Association for the Advancement of Veterinary Parasitology (W.A.A.V.P.): Third edition of the guideline for evaluating efficacy of anthelmintics in ruminants (bovine, ovine, caprine). Vet Parasitol 2024; 329:110187. [PMID: 38728835 DOI: 10.1016/j.vetpar.2024.110187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 04/15/2024] [Accepted: 04/15/2024] [Indexed: 05/12/2024]
Abstract
This guideline is aimed at those who are involved in the assessment of anthelmintic efficacy in ruminant livestock species (bovine, ovine and caprine). The intent is to provide a framework that can be adopted worldwide for the testing of anthelmintics in ruminants, such that studies carried out in different countries can be compared and thereby unnecessary duplication can be reduced. Recommendations are made for the selection, housing and feeding of study animals, the type of studies required, the method used to conduct those studies, the assessment of results and the standards for defining anthelmintic efficacy.
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Affiliation(s)
- D J Burden
- Duilio Veterinary Parasitology, The Vicarage, Church Lane, Churcham, Gloucester, UK.
| | - D J Bartley
- Disease Control, Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, UK
| | - R B Besier
- College of Environmental and Life Sciences, Murdoch University, Perth, WA, Australia
| | - E Claerebout
- Laboratory for Parasitology, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - T P Elliott
- Centre for Animal Research and Teaching, University of New England, Armidale, NSW, Australia
| | - J Höglund
- Section for Parasitology, Faculty of Veterinary Medicine and Animal Science, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - S Rehbein
- Boehringer Ingelheim Vetmedica GmbH, Kathrinenhof Research Center, Rohrdorf, Germany
| | - J F J Torres-Acosta
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico
| | - J A Van Wyk
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| | - T Yazwinski
- University of Arkansas, Fayetteville, AR, USA
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Hamad MH, Islam SI, Jitsamai W, Chinkangsadarn T, Naraporn D, Ouisuwan S, Taweethavonsawat P. Metabarcoding study to reveal the structural community of strongylid nematodes in domesticated horses in Thailand. BMC Vet Res 2024; 20:70. [PMID: 38395874 PMCID: PMC10893705 DOI: 10.1186/s12917-024-03934-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 02/12/2024] [Indexed: 02/25/2024] Open
Abstract
BACKGROUND Mixed strongylid infections significantly impact equine health and performance. Traditional microscopy-based methods exhibit limitations in accurately identifying strongylid species. Nemabiome deep amplicon sequencing approach previously succeeded in describing the strongylid communities in livestock including equids. However, there are no available studies that describe the structural communities of strongylid parasites in horses in Thailand. Therefore, this study was undertaken encompassing the ITS-2 rDNA metabarcoding assay to characterize strongylid species within horse fecal samples collected from a cohort of yearlings at the largest domesticated stud farm in Thailand. In addition, to investigate the capability of ITS-2 rDNA in assessing the phylogenetic relationships among the identified strongylid species. RESULTS The study identified 14 strongylid species in the examined equine populations, each with varying prevalence. Notably, Cylicocyclus nassatus and Cylicostephanus longibursatus were identified as the predominant species, with Strongylus spp. conspicuously absent. The phylogenetic analysis of 207 amplicon sequence variants (ASVs) displayed a complex relationship among the investigated cyathostomin species, with some species are positioned across multiple clades, demonstrating close associations with various species and genera. CONCLUSION The ITS-2 nemabiome sequencing technique provided a detailed picture of horse strongylid parasite species in the studied population. This establishes a foundation for future investigations into the resistance status of these parasites and enables efforts to mitigate their impact.
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Affiliation(s)
- Mohamed H Hamad
- The International Graduate Program of Veterinary Science and Technology (VST), Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand
- Infectious Diseases, Department of Animal Medicine, Faculty of Veterinary Medicine, Zagazig University, Zagazig, 44511, Egypt
- Parasitology Unit, Department of Veterinary Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Sk Injamamul Islam
- The International Graduate Program of Veterinary Science and Technology (VST), Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand
- Parasitology Unit, Department of Veterinary Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Wanarit Jitsamai
- Department of Parasitology and Entomology, Faculty of Public Health, Mahidol University, Bangkok, Thailand
| | - Teerapol Chinkangsadarn
- Department of Surgery, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Darm Naraporn
- Horse Farm and Laboratory Animal Breeding Center, Queen Saovabha Memorial Institute, The Thai Red Cross Society, Hua-Hin, Prachuap Khiri Khan Province, 77110, Thailand
| | - Suraseha Ouisuwan
- Horse Farm and Laboratory Animal Breeding Center, Queen Saovabha Memorial Institute, The Thai Red Cross Society, Hua-Hin, Prachuap Khiri Khan Province, 77110, Thailand
| | - Piyanan Taweethavonsawat
- Parasitology Unit, Department of Veterinary Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand.
- Biomarkers in Animals Parasitology Research Unit, Chulalongkorn University, Bangkok, 10330, Thailand.
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Hamad MH, Islam SI, Jitsamai W, Chinkangsadarn T, Naraporn D, Ouisuwan S, Taweethavonsawat P. Patterns of Equine Small Strongyle Species Infection after Ivermectin Intervention in Thailand: Egg Reappearance Period and Nemabiome Metabarcoding Approach. Animals (Basel) 2024; 14:574. [PMID: 38396542 PMCID: PMC10886017 DOI: 10.3390/ani14040574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 02/07/2024] [Accepted: 02/07/2024] [Indexed: 02/25/2024] Open
Abstract
The indiscriminate use of anthelmintics to control parasitic nematodes in horses has led to the emergence of anthelmintic resistance worldwide. However, there are no data available on using ivermectin for treating strongyle infections within domesticated horses in Thailand. Therefore, this study aimed to use the fecal egg count reduction (FECR) test to determine the strongylid egg reappearance period (ERP). Additionally, the nemabiome metabarcoding approach is incorporated to study patterns of strongyle species infection following ivermectin treatment. The study results indicate that, although ivermectin effectively eliminated adult strongyle parasites within two weeks post-treatment, the ERP was shortened to 6 weeks post-treatment with a mean FECR of 70.4% (95% CI 46.1-84.0). This potentially indicates a recent change in drug performance. In addition, nemabiome metabarcoding revealed that strongyle species have different levels of susceptibility in response to anthelmintic drugs. The reduction in ERP was associated with the early reappearance of specific species, dominated by Cylicostephanus longibursatus and Cylicocyclus nassatus, indicating the lower susceptibility of these species. In contrast, Poteriostomum imparidentatum, Triodontophorus nipponicus, and Triodontophorus serratus were not found post-treatment, indicating the high level of susceptibility of these species. This information is vital for comprehending the factors contributing to the emergence of resistance and for devising strategies to manage and control strongyle infections in horses.
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Affiliation(s)
- Mohamed H. Hamad
- The International Graduate Program of Veterinary Science and Technology (VST), Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand; (M.H.H.); (S.I.I.)
- Department of Animal Infectious Diseases, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44511, Egypt
- Parasitology Unit, Department of Veterinary Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Sk Injamamul Islam
- The International Graduate Program of Veterinary Science and Technology (VST), Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand; (M.H.H.); (S.I.I.)
- Parasitology Unit, Department of Veterinary Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Wanarit Jitsamai
- Department of Parasitology and Entomology, Faculty of Public Health, Mahidol University, Bangkok 10400, Thailand;
| | - Teerapol Chinkangsadarn
- Department of Surgery, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand;
| | - Darm Naraporn
- Horse Farm and Laboratory Animal Breeding Center, Queen Saovabha Memorial Institute, The Thai Red Cross Society, Hua-Hin 77110, Thailand; (D.N.); (S.O.)
| | - Suraseha Ouisuwan
- Horse Farm and Laboratory Animal Breeding Center, Queen Saovabha Memorial Institute, The Thai Red Cross Society, Hua-Hin 77110, Thailand; (D.N.); (S.O.)
| | - Piyanan Taweethavonsawat
- Parasitology Unit, Department of Veterinary Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand
- Biomarkers in Animals Parasitology Research Unit, Chulalongkorn University, Bangkok 10330, Thailand
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Owens LA, Friant S, Martorelli Di Genova B, Knoll LJ, Contreras M, Noya-Alarcon O, Dominguez-Bello MG, Goldberg TL. VESPA: an optimized protocol for accurate metabarcoding-based characterization of vertebrate eukaryotic endosymbiont and parasite assemblages. Nat Commun 2024; 15:402. [PMID: 38195557 PMCID: PMC10776621 DOI: 10.1038/s41467-023-44521-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 12/15/2023] [Indexed: 01/11/2024] Open
Abstract
Protocols for characterizing taxonomic assemblages by deep sequencing of short DNA barcode regions (metabarcoding) have revolutionized our understanding of microbial communities and are standardized for bacteria, archaea, and fungi. Unfortunately, comparable methods for host-associated eukaryotes have lagged due to technical challenges. Despite 54 published studies, issues remain with primer complementarity, off-target amplification, and lack of external validation. Here, we present VESPA (Vertebrate Eukaryotic endoSymbiont and Parasite Analysis) primers and optimized metabarcoding protocol for host-associated eukaryotic community analysis. Using in silico prediction, panel PCR, engineered mock community standards, and clinical samples, we demonstrate VESPA to be more effective at resolving host-associated eukaryotic assemblages than previously published methods and to minimize off-target amplification. When applied to human and non-human primate samples, VESPA enables reconstruction of host-associated eukaryotic endosymbiont communities more accurately and at finer taxonomic resolution than microscopy. VESPA has the potential to advance basic and translational science on vertebrate eukaryotic endosymbiont communities, similar to achievements made for bacterial, archaeal, and fungal microbiomes.
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Affiliation(s)
- Leah A Owens
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA.
| | - Sagan Friant
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA
- Department of Anthropology, The Pennsylvania State University, University Park, PA, USA
- Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Bruno Martorelli Di Genova
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
- Department of Microbiology and Molecular Genetics, Larner College of Medicine, The University of Vermont, Burlington, VT, USA
| | - Laura J Knoll
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
| | - Monica Contreras
- Center for Biophysics and Biochemistry, Venezuelan Institute of Scientific Research (IVIC), Caracas, Venezuela
| | - Oscar Noya-Alarcon
- Centro Amazónico de Investigación y Control de Enfermedades Tropicales-CAICET, Puerto Ayacucho, Amazonas, Venezuela
| | - Maria G Dominguez-Bello
- Department of Biochemistry and Microbiology, Rutgers University-New Brunswick, New Brunswick, NJ, USA
- Department of Anthropology, Rutgers University, New Brunswick, NJ, USA
- Institute for Food, Nutrition and Health, Rutgers University, New Brunswick, NJ, USA
- Canadian Institute for Advanced Research (CIFAR), Toronto, ON, Canada
| | - Tony L Goldberg
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA.
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Lobanov VA, Konecsni KA, Scandrett WB, Jenkins EJ. Identification of Trichinella taxa by ITS-1 amplicon next-generation sequencing with an improved resolution for detecting underrepresented genotypes in mixed natural infections. Parasit Vectors 2023; 16:466. [PMID: 38129932 PMCID: PMC10734138 DOI: 10.1186/s13071-023-06035-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 10/29/2023] [Indexed: 12/23/2023] Open
Abstract
BACKGROUND Amplicon-based next-generation sequencing (NGS) has rapidly gained popularity as a powerful method for delineating taxa in complex communities, including helminths. Here, we applied this approach to identify species and genotypes of zoonotic nematodes of the Trichinella genus. A known limitation of the current multiplex PCR (mPCR) assay recommended by the International Commission on Trichinellosis is that it does not differentiate Trichinella nativa from T. chanchalensis. METHODS The new assay entails deep sequencing of an amplified variable fragment of the ribosomal cistron's (rDNA) internal transcribed spacer 1 using the Illumina platform. The assay was evaluated using first-stage larvae (L1) of select laboratory strains of various Trichinella taxa mixed in known proportions and then validated using archived L1 from 109 wildlife hosts. The species/genotypes of these L1 isolates from wildlife were previously determined using mPCR. RESULTS NGS data analysis for Trichinella laboratory strains selected as representative of North American fauna revealed a sequence representation bias. Trichinella pseudospiralis, a non-encapsulated species, was the most underrepresented when mixed with T. spiralis, T. murrelli, T. nativa and Trichinella T6 in equal quantities. However, five L1 of T. pseudospiralis were readily revealed by NGS in a mix with 2000 L1 of T. nativa (1:400 ratio). From naturally infected wildlife, all Trichinella taxa revealed by mPCR were also identified by NGS in 103 of 107 (96.3%) samples amplified on both assays. NGS identified additional taxa in 11 (10.3%) samples, whereas additional taxa were revealed by mPCR in only four (3.7%) samples. Most isolates comprised single or mixed infections of T. nativa and Trichinella T6. On NGS, T. chanchalensis (T13) was detected in combination with Trichinella T6 in a wolverine (Gulo gulo) and in combination with T. nativa and Trichinella T6 in a marten (Martes americana) from the Northwest Territories, Canada. CONCLUSIONS This new NGS assay demonstrates strong potential as a single assay for identifying all recognised Trichinella taxa as well as improved sensitivity for detecting under-represented and novel genotypes in mixed infections. In addition, we report a new host record for T. chanchalensis in American marten.
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Affiliation(s)
- Vladislav A Lobanov
- Center for Food-borne and Animal Parasitology, Canadian Food Inspection Agency, Saskatoon, SK, Canada.
| | - Kelly A Konecsni
- Center for Food-borne and Animal Parasitology, Canadian Food Inspection Agency, Saskatoon, SK, Canada
| | - W Brad Scandrett
- Center for Food-borne and Animal Parasitology, Canadian Food Inspection Agency, Saskatoon, SK, Canada
| | - Emily J Jenkins
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
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Khangembam R, Vass N, Morrison A, Melville LA, Antonopoulos A, Czeglédi L. Preliminary results of the recombinase polymerase amplification technique for the detection of Haemonchus contortus from Hungarian field samples. Vet Parasitol 2023; 320:109974. [PMID: 37354888 DOI: 10.1016/j.vetpar.2023.109974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 06/07/2023] [Accepted: 06/14/2023] [Indexed: 06/26/2023]
Abstract
Haemonchus contortus is a parasitic nematode of small ruminants responsible for significant economic losses and animal health concerns globally. Detection of gastrointestinal nematode (GIN) infection in veterinary practice typically relies on microscopy-based methods such as the faecal egg count and morphological identification of larval culture. However, mixed co-infections are common and species-specific identification is typically time-consuming and expertise-intensive. Compounded by increasing anthelmintic resistance, there is an urgent need to implement the molecular diagnosis of GIN in the livestock industry, preferably in field settings. Advances in isothermal amplification techniques including recombinase polymerase amplification (RPA) assays could improve this. Yet, constraints in RPA kit availability and amplicon detection systems limit the use of this technology in point of care settings. In this study, we present an early-stage, proof-of-concept demonstration of RPA targeting the internal transcribed spacer (ITS2) region of H. contortus. Having tested against eight closely related nematodes and also against five farm isolates in Eastern Hungary, preliminary results derived from a comparative analysis of 3 primer sets showed the assay detects H. contortus DNA and has a limit of detection of 10-5 ng/μl. We also tested an end-result naked eye detection system using various DNA binding dyes, of which EvaGreen® dye was successful for a qualitative RPA detection that could be adaptable at farm sites.
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Affiliation(s)
- Rojesh Khangembam
- Doctoral School of Animal Science, Faculty of Agricultural and Environmental Management, University of Debrecen, Böszörményi ut. 138, Debrecen 4032, Hungary; Department of Animal Science, Institute of Animal Science, Biotechnology and Nature Conservation, Faculty of Agricultural and Environmental Management, University of Debrecen, Böszörményi ut. 138, Debrecen 4032, Hungary.
| | - Nóra Vass
- Department of Animal Science, Institute of Animal Science, Biotechnology and Nature Conservation, Faculty of Agricultural and Environmental Management, University of Debrecen, Böszörményi ut. 138, Debrecen 4032, Hungary
| | - Alison Morrison
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Scotland, UK
| | - Lynsey A Melville
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Scotland, UK
| | - Alistair Antonopoulos
- School of Biodiversity, One Health, and Veterinary Medicine, University of Glasgow, Glasgow, Scotland, UK; Kreavet, Kruibeke, Belgium.
| | - Levente Czeglédi
- Department of Animal Science, Institute of Animal Science, Biotechnology and Nature Conservation, Faculty of Agricultural and Environmental Management, University of Debrecen, Böszörményi ut. 138, Debrecen 4032, Hungary
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Kaplan RM, Denwood MJ, Nielsen MK, Thamsborg SM, Torgerson PR, Gilleard JS, Dobson RJ, Vercruysse J, Levecke B. World Association for the Advancement of Veterinary Parasitology (W.A.A.V.P.) guideline for diagnosing anthelmintic resistance using the faecal egg count reduction test in ruminants, horses and swine. Vet Parasitol 2023; 318:109936. [PMID: 37121092 DOI: 10.1016/j.vetpar.2023.109936] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Accepted: 04/18/2023] [Indexed: 05/02/2023]
Abstract
The faecal egg count reduction test (FECRT) remains the method of choice for establishing the efficacy of anthelmintic compounds in the field, including the diagnosis of anthelmintic resistance. We present a guideline for improving the standardization and performance of the FECRT that has four sections. In the first section, we address the major issues relevant to experimental design, choice of faecal egg count (FEC) method, statistical analysis, and interpretation of the FECRT results. In the second section, we make a series of general recommendations that are applicable across all animals addressed in this guideline. In the third section, we provide separate guidance details for cattle, small ruminants (sheep and goats), horses and pigs to address the issues that are specific to the different animal types. Finally, we provide overviews of the specific details required to conduct an FECRT for each of the different host species. To address the issues of statistical power vs. practicality, we also provide two separate options for each animal species; (i) a version designed to detect small changes in efficacy that is intended for use in scientific studies, and (ii) a less resource-intensive version intended for routine use by veterinarians and livestock owners to detect larger changes in efficacy. Compared to the previous FECRT recommendations, four important differences are noted. First, it is now generally recommended to perform the FECRT based on pre- and post-treatment FEC of the same animals (paired study design), rather than on post-treatment FEC of both treated and untreated (control) animals (unpaired study design). Second, instead of requiring a minimum mean FEC (expressed in eggs per gram (EPG)) of the group to be tested, the new requirement is for a minimum total number of eggs to be counted under the microscope (cumulative number of eggs counted before the application of a conversion factor). Third, we provide flexibility in the required size of the treatment group by presenting three separate options that depend on the (expected) number of eggs counted. Finally, these guidelines address all major livestock species, and the thresholds for defining reduced efficacy are adapted and aligned to host species, anthelmintic drug and parasite species. In conclusion, these new guidelines provide improved methodology and standardization of the FECRT for all major livestock species.
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Affiliation(s)
- Ray M Kaplan
- Pathobiology Department, School of Veterinary Medicine, St. George's University, W.I., Grenada.
| | - Matthew J Denwood
- Department of Veterinary and Animal Sciences, University of Copenhagen, Denmark
| | - Martin K Nielsen
- Maxwell H. Gluck Equine Research Center, University of Kentucky, KY, USA
| | - Stig M Thamsborg
- Department of Veterinary and Animal Sciences, University of Copenhagen, Denmark
| | - Paul R Torgerson
- Section of Epidemiology, Vetsuisse Faculty, University of Zürich, Switzerland
| | - John S Gilleard
- Department of Comparative Biology and Experimental Medicine, Host-Parasite Interactions Program, Faculty of Veterinary Medicine, University of Calgary, Alberta, Canada
| | - Robert J Dobson
- School of Veterinary and Life Sciences, Murdoch University, Australia
| | - Jozef Vercruysse
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
| | - Bruno Levecke
- Department of Translational Physiology, Infectiology and Public Health, Ghent University, Merelbeke, Belgium
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10
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Thorn CS, Maness RW, Hulke JM, Delmore KE, Criscione CD. Population genomics of helminth parasites. J Helminthol 2023; 97:e29. [PMID: 36927601 DOI: 10.1017/s0022149x23000123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
Next generation sequencing technologies have facilitated a shift from a few targeted loci in population genetic studies to whole genome approaches. Here, we review the types of questions and inferences regarding the population biology and evolution of parasitic helminths being addressed within the field of population genomics. Topics include parabiome, hybridization, population structure, loci under selection and linkage mapping. We highlight various advances, and note the current trends in the field, particularly a focus on human-related parasites despite the inherent biodiversity of helminth species. We conclude by advocating for a broader application of population genomics to reflect the taxonomic and life history breadth displayed by helminth parasites. As such, our basic knowledge about helminth population biology and evolution would be enhanced while the diversity of helminths in itself would facilitate population genomic comparative studies to address broader ecological and evolutionary concepts.
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Affiliation(s)
- C S Thorn
- Department of Biology, Texas A&M University, 3258 TAMU, College Station, TX, 77843, USA
| | - R W Maness
- Department of Biology, Texas A&M University, 3258 TAMU, College Station, TX, 77843, USA
| | - J M Hulke
- Department of Biology, Texas A&M University, 3258 TAMU, College Station, TX, 77843, USA
| | - K E Delmore
- Department of Biology, Texas A&M University, 3258 TAMU, College Station, TX, 77843, USA
| | - C D Criscione
- Department of Biology, Texas A&M University, 3258 TAMU, College Station, TX, 77843, USA
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Davey ML, Kamenova S, Fossøy F, Solberg EJ, Davidson R, Mysterud A, Rolandsen CM. Faecal metabarcoding provides improved detection and taxonomic resolution for non-invasive monitoring of gastrointestinal nematode parasites in wild moose populations. Parasit Vectors 2023; 16:19. [PMID: 36653864 PMCID: PMC9847159 DOI: 10.1186/s13071-022-05644-6] [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: 07/06/2022] [Accepted: 12/28/2022] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Although wild ungulate populations are heavily monitored throughout Europe, we understand little of how parasites affect population dynamics, and there is no systematic, long-term monitoring of parasite diversity and parasite loads. Such monitoring is in part hampered by a lack of time- and cost-effective assay methodologies with high sensitivity and good taxonomic resolution. DNA metabarcoding has been successfully used to characterize the parasitic nemabiome with high taxonomic resolution in a variety of wild and domestic hosts. However, in order to implement this technique in large-scale, potentially non-invasive monitoring of gastrointestinal parasitic nematodes (GIN), protocol optimization is required to maximize biodiversity detection, whilst maintaining time- and cost-effectiveness. METHODS Faecal samples were collected from a wild moose population and GIN communities were characterized and quantified using both parasitological techniques (egg and larva counting) and DNA metabarcoding of the ITS2 region of rDNA. Three different isolation methods were compared that differed in the volume of starting material and cell lysis method. RESULTS Similar nematode faunas were recovered from all samples using both parasitological and metabarcoding methods, and the approaches were largely congruent. However, metabarcoding assays showed better taxonomic resolution and slightly higher sensitivity than egg and larvae counts. The metabarcoding was not strictly quantitative, but the proportion of target nematode sequences recovered was correlated with the parasitologically determined parasite load. Species detection rates in the metabarcoding assays were maximized using a DNA isolation method that included mechanical cell disruption and maximized the starting material volume. CONCLUSIONS DNA metabarcoding is a promising technique for the non-invasive, large-scale monitoring of parasitic GINs in wild ungulate populations, owing to its high taxonomic resolution, increased assay sensitivity, and time- and cost-effectiveness. Although metabarcoding is not a strictly quantitative method, it may nonetheless be possible to create a management- and conservation-relevant index for the host parasite load from this data. To optimize the detection rates and time- and cost-effectiveness of metabarcoding assays, we recommend choosing a DNA isolation method that involves mechanical cell disruption and maximizes the starting material volume.
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Affiliation(s)
- Marie L. Davey
- grid.420127.20000 0001 2107 519XNorwegian Institute for Nature Research (NINA), Trondheim, Norway
| | - Stefaniya Kamenova
- grid.5510.10000 0004 1936 8921University of Oslo, Oslo, Norway ,grid.19477.3c0000 0004 0607 975XNorwegian University of Life Sciences, Ås, Norway
| | - Frode Fossøy
- grid.420127.20000 0001 2107 519XNorwegian Institute for Nature Research (NINA), Trondheim, Norway
| | - Erling J. Solberg
- grid.420127.20000 0001 2107 519XNorwegian Institute for Nature Research (NINA), Trondheim, Norway
| | - Rebecca Davidson
- grid.410549.d0000 0000 9542 2193Norwegian Veterinary Institute, Tromsø, Norway
| | - Atle Mysterud
- grid.420127.20000 0001 2107 519XNorwegian Institute for Nature Research (NINA), Trondheim, Norway ,grid.5510.10000 0004 1936 8921University of Oslo, Oslo, Norway
| | - Christer M. Rolandsen
- grid.420127.20000 0001 2107 519XNorwegian Institute for Nature Research (NINA), Trondheim, Norway
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12
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Johnson WL, Reynolds S, Adkins CL, Wehus-Tow B, Brennan J, Krus CB, Buttke D, Martin JM, Jesudoss Chelladurai JR. A comparison of Mini-FLOTAC and McMaster techniques, overdispersion and prevalence of parasites in naturally infected North American bison (Bison bison) in the USA. CURRENT RESEARCH IN PARASITOLOGY & VECTOR-BORNE DISEASES 2022; 2:100103. [PMID: 36437837 PMCID: PMC9684701 DOI: 10.1016/j.crpvbd.2022.100103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 10/31/2022] [Accepted: 11/01/2022] [Indexed: 11/09/2022]
Abstract
Several quantitative diagnostic techniques are available to estimate gastrointestinal parasite counts in the feces of ruminants. Comparing egg and oocyst magnitudes in naturally infected samples has been a recommended approach to rank fecal techniques. In this study, we compared the Mini-FLOTAC (sensitivity of 5 eggs per gram (EPG)/oocysts per gram (OPG)) and different averaged replicates of the modified McMaster techniques (sensitivity of 33.33 EPG/OPG) in 387 fecal samples from 10 herds of naturally infected North American bison in the Central Great Plains region of the USA. Both techniques were performed with fecal slurries homogenized in a fill-FLOTAC device. In the study population, prevalence of strongyle eggs, Eimeria spp. oocysts, Moniezia spp. eggs and Trichuris spp. eggs was 81.4%, 73.9%, 7.5%, and 3.1%, respectively. Counts of strongyle eggs and Eimeria spp. oocysts obtained from 1 to 3 averaged technical replicates of the modified McMaster technique were compared to a single replicate of the Mini-FLOTAC. Correlation between the two techniques increased with an increase in the number of averaged technical replicates of the modified McMaster technique used to calculate EGP/OPG. The correlation for Moniezia spp. EPG when averaged triplicates of the modified McMaster technique were compared to a single replicate of the Mini-FLOTAC count was high; however, the correlation for Trichuris spp. eggs was low. Additionally, we used averaged counts from both techniques to show the overdispersion of parasites in bison herds. Mini-FLOTAC is an acceptable alternative to the McMaster for bison parasites. Increasing technical replicates of McMaster increases correlation with mini-FLOTAC. Gastrointestinal parasites are overdispersed in bison.
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Affiliation(s)
- William L. Johnson
- Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, KS, USA
| | - Samantha Reynolds
- Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, KS, USA
| | - Colton L. Adkins
- Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, KS, USA
| | - Bradly Wehus-Tow
- Department of Animal Science, South Dakota State University, Rapid City, SD, USA
| | - Jameson Brennan
- Department of Animal Science, South Dakota State University, Rapid City, SD, USA
| | - Catherine B. Krus
- Department of Clinical Sciences, Colorado State University, Fort Collins, CO, USA
| | | | - Jeff M. Martin
- Center of Excellence for Bison Studies, South Dakota State University, Rapid City, SD, USA
| | - Jeba R.J. Jesudoss Chelladurai
- Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, KS, USA
- Corresponding author.
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Rinaldi L, Krücken J, Martinez-Valladares M, Pepe P, Maurelli MP, de Queiroz C, Castilla Gómez de Agüero V, Wang T, Cringoli G, Charlier J, Gilleard JS, von Samson-Himmelstjerna G. Advances in diagnosis of gastrointestinal nematodes in livestock and companion animals. ADVANCES IN PARASITOLOGY 2022; 118:85-176. [PMID: 36088084 DOI: 10.1016/bs.apar.2022.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Diagnosis of gastrointestinal nematodes in livestock and companion animals has been neglected for years and there has been an historical underinvestment in the development and improvement of diagnostic tools, undermining the undoubted utility of surveillance and control programmes. However, a new impetus by the scientific community and the quickening pace of technological innovations, are promoting a renaissance of interest in developing diagnostic capacity for nematode infections in veterinary parasitology. A cross-cutting priority for diagnostic tools is the development of pen-side tests and associated decision support tools that rapidly inform on the levels of infection and morbidity. This includes development of scalable, parasite detection using artificial intelligence for automated counting of parasitic elements and research towards establishing biomarkers using innovative molecular and proteomic methods. The aim of this review is to assess the state-of-the-art in the diagnosis of helminth infections in livestock and companion animals and presents the current advances of diagnostic methods for intestinal parasites harnessing (i) automated methods for copromicroscopy based on artificial intelligence, (ii) immunodiagnosis, and (iii) molecular- and proteome-based approaches. Regardless of the method used, multiple factors need to be considered before diagnostics test results can be interpreted in terms of control decisions. Guidelines on how to apply diagnostics and how to interpret test results in different animal species are increasingly requested and some were recently made available in veterinary parasitology for the different domestic species.
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Affiliation(s)
- Laura Rinaldi
- Department of Veterinary Medicine and Animal Production, University of Naples "Federico II", Naples, Italy.
| | - J Krücken
- Institute for Parasitology and Tropical Veterinary Medicine, Veterinary Centre for Resistance Research, Freie Universität Berlin, Berlin, Germany
| | - M Martinez-Valladares
- Instituto de Ganadería de Montaña (CSIC-Universidad de León), Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, León, Spain
| | - P Pepe
- Department of Veterinary Medicine and Animal Production, University of Naples "Federico II", Naples, Italy
| | - M P Maurelli
- Department of Veterinary Medicine and Animal Production, University of Naples "Federico II", Naples, Italy
| | - C de Queiroz
- Faculty of Veterinary Medicine, 3331 Hospital Drive, Host-Parasite Interactions (HPI) Program University of Calgary, Calgary, Alberta, Canada; Faculty of Veterinary Medicine, St Georges University, Grenada
| | - V Castilla Gómez de Agüero
- Instituto de Ganadería de Montaña (CSIC-Universidad de León), Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, León, Spain
| | - T Wang
- Kreavet, Kruibeke, Belgium
| | - Giuseppe Cringoli
- Department of Veterinary Medicine and Animal Production, University of Naples "Federico II", Naples, Italy
| | | | - J S Gilleard
- Faculty of Veterinary Medicine, 3331 Hospital Drive, Host-Parasite Interactions (HPI) Program University of Calgary, Calgary, Alberta, Canada
| | - G von Samson-Himmelstjerna
- Institute for Parasitology and Tropical Veterinary Medicine, Veterinary Centre for Resistance Research, Freie Universität Berlin, Berlin, Germany
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Baltrušis P, Halvarsson P, Höglund J. Estimation of the impact of three different bioinformatic pipelines on sheep nemabiome analysis. Parasit Vectors 2022; 15:290. [PMID: 35953825 PMCID: PMC9373329 DOI: 10.1186/s13071-022-05399-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 07/13/2022] [Indexed: 11/10/2022] Open
Abstract
Background Next-generation sequencing (NGS) has provided an alternative strategy to study the composition of nematode communities with increased resolution and sensitivity. However, the handling and processing of gigabytes worth of amplicon sequence data produced by an NGS platform is still a major hurdle, limiting the use and adoption of faster and more convenient analysis software. Methods In total 32 paired, fecal samples from Swedish sheep flocks were cultured and the larvae subsequently harvested subjected to internal transcribed spacer 2 (ITS2) amplicon sequencing using the PacBio platform. Samples were analyzed with three different bioinformatic pipelines, i.e. the DADA2, Mothur and SCATA pipelines, to determine species composition and richness. Results For the the major species tested in this study (Haemonchus contortus, Teladorsagia circumcinta and Trichostrongylus colubriformis) neither relative abundances nor species diversity differed significantly between the three pipelines, effectively showing that all three analysis pipelines, although different in their approaches, yield nearly identical outcomes. In addition, the samples analyzed here had especially high frequencies of H. contortus (90–95% across the three pipelines) both before and after sample treatment, followed by T. circumcinta (3.5–4%). This shows that H. contortus is the parasite of primary importance in contemporary Swedish sheep farms struggling with anthelmintic resistance. Finally, although on average a significant reduction in egg counts was achieved post-treatment, no significant shifts in major species relative frequencies occurred, indicating highly rigid community structures at sheep farms where anthelmintic resistance has been reported. Conclusions The findings presented here further contribute to the development and application of NGS technology to study nemabiome compositions in sheep, in addition to expanding our understanding about the most recent changes in parasite species abundances from Swedish sheep farms struggling with anthelmintic resistance. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-022-05399-0.
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Affiliation(s)
- Paulius Baltrušis
- Section for Parasitology, Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden.
| | - Peter Halvarsson
- Section for Parasitology, Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Johan Höglund
- Section for Parasitology, Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden
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15
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A.Danks H, Sobotyk C, N.Saleh M, Kulpa M, L.Luksovsky J, C Jones L, G. Verocai G. Opening a can of lungworms: Molecular characterization of Dictyocaulus (Nematoda: Dictyocaulidae) infecting North American bison (Bison bison). Int J Parasitol Parasites Wildl 2022; 18:128-134. [PMID: 35572037 PMCID: PMC9096256 DOI: 10.1016/j.ijppaw.2022.04.011] [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: 04/07/2022] [Revised: 04/26/2022] [Accepted: 04/26/2022] [Indexed: 11/27/2022]
Abstract
Dictyocaulus is a globally distributed genus of lungworms of domestic and wild ungulates. Dictyocaulus adults inhabit the bronchi, frequently causing subclinical and clinical disease, and that impacts animal health and production. North American bison (Bison bison) and cattle (Bos taurus) share various parasitic nematode species, particularly in areas where co-grazing occurs. The current assumption is that North American bison share the lungworm D. viviparus with cattle, but this has not been confirmed on a molecular basis. The aim of this study was to molecularly characterize Dictyocaulus lungworm isolates from North American plains bison (Bison bison bison). Fecal samples were collected from 5 wild conservation bison herds located in Iowa, North Dakota, Oklahoma, Colorado, and Montana in 2019 and 2020, and from ranched and feedlot bison from 2 herds in Oklahoma and Texas. First-stage lungworm larvae (L1) were isolated via Baermann technique. Genomic DNA was extracted from L1s of up to 3 samples per herd and followed by PCR and sequencing targeting the internal transcribed spacer 2 (ITS2) region of the nuclear ribosomal DNA and the partial cytochrome oxidase c subunit 1 (cox1) of mitochondrial DNA. Phylogenetic analyses were performed in MEGA X 10.1. Sequences of North American plains bison Dictyocaulus belong to a single, uncharacterized species, clustering in well-supported clades (100% and 100% bootstrap support for ITS2 and cox1, respectively), differing from D. viviparus of cattle in North America and Europe, and European bison (Bison bonasus). Our results contradict previous assumptions regarding parasite identity, highlighting the need for characterization of this species through morphological and molecular methods, elucidating its biology and host range, and potential impact on host health. Further investigation into the biodiversity of Dictyocaulus species infecting bovids and cervids in North America is warranted. We molecularly characterized Dictyocalus of North American plains bison in the USA. Dictyocaulus sp. in USA plains bison differs significantly from D. viviparus of cattle. Dictyocaulus sp. of USA plains bison may belong to an uncharacterized species. Future studies should integrate classical and molecular methods on adult specimens.
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Papaiakovou M, Littlewood DTJ, Doyle SR, Gasser RB, Cantacessi C. Worms and bugs of the gut: the search for diagnostic signatures using barcoding, and metagenomics-metabolomics. Parasit Vectors 2022; 15:118. [PMID: 35365192 PMCID: PMC8973539 DOI: 10.1186/s13071-022-05225-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 02/25/2022] [Indexed: 02/07/2023] Open
Abstract
Gastrointestinal (GI) helminth infections cause significant morbidity in both humans and animals worldwide. Specific and sensitive diagnosis is central to the surveillance of such infections and to determine the effectiveness of treatment strategies used to control them. In this article, we: (i) assess the strengths and limitations of existing methods applied to the diagnosis of GI helminth infections of humans and livestock; (ii) examine high-throughput sequencing approaches, such as targeted molecular barcoding and shotgun sequencing, as tools to define the taxonomic composition of helminth infections; and (iii) discuss the current understanding of the interactions between helminths and microbiota in the host gut. Stool-based diagnostics are likely to serve as an important tool well into the future; improved diagnostics of helminths and their environment in the gut may assist the identification of biomarkers with the potential to define the health/disease status of individuals and populations, and to identify existing or emerging anthelmintic resistance.
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Affiliation(s)
- Marina Papaiakovou
- Department of Veterinary Medicine, University of Cambridge, Cambridge, CB3 0ES UK
- Department of Life Sciences, Natural History Museum, Cromwell Road, London, SW7 5BD UK
| | | | | | - Robin B. Gasser
- Melbourne Veterinary School, The University of Melbourne, Parkville, VIC 3010 Australia
| | - Cinzia Cantacessi
- Department of Veterinary Medicine, University of Cambridge, Cambridge, CB3 0ES UK
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Cháves-González LE, Morales-Calvo F, Mora J, Solano-Barquero A, Verocai GG, Rojas A. What lies behind the curtain: Cryptic diversity in helminth parasites of human and veterinary importance. CURRENT RESEARCH IN PARASITOLOGY & VECTOR-BORNE DISEASES 2022; 2:100094. [PMID: 35800064 PMCID: PMC9253710 DOI: 10.1016/j.crpvbd.2022.100094] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 05/28/2022] [Accepted: 06/07/2022] [Indexed: 11/17/2022]
Abstract
Parasite cryptic species are morphologically indistinguishable but genetically distinct organisms, leading to taxa with unclear species boundaries. Speciation mechanisms such as cospeciation, host colonization, taxon pulse, and oscillation may lead to the emergence of cryptic species, influencing host-parasite interactions, parasite ecology, distribution, and biodiversity. The study of cryptic species diversity in helminth parasites of human and veterinary importance has gained relevance, since their distribution may affect clinical and epidemiological features such as pathogenicity, virulence, drug resistance and susceptibility, mortality, and morbidity, ultimately affecting patient management, course, and outcome of treatment. At the same time, the need for recognition of cryptic species diversity has implied a transition from morphological to molecular diagnostic methods, which are becoming more available and accessible in parasitology. Here, we discuss the general approaches for cryptic species delineation and summarize some examples found in nematodes, trematodes and cestodes of medical and veterinary importance, along with the clinical implications of their taxonomic status. Lastly, we highlight the need for the correct interpretation of molecular information, and the correct use of definitions when reporting or describing new cryptic species in parasitology, since molecular and morphological data should be integrated whenever possible. Cryptic diversity has been described in helminths of human and animal importance. Cryptic species are morphologically indistinguishable but genetically distinct organisms. These entities emerge by different evolutionary and speciation mechanisms. Analysis of molecular and morphological data is needed for cryptic species delimitation. Cryptic diversity may affect pathogenicity, virulence and drug resistance of helminths.
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Affiliation(s)
- Luis Enrique Cháves-González
- Laboratory of Helminthology, Centro de Investigación en Enfermedades Tropicales, University of Costa Rica, San José, Costa Rica
| | - Fernando Morales-Calvo
- Laboratory of Helminthology, Centro de Investigación en Enfermedades Tropicales, University of Costa Rica, San José, Costa Rica
| | - Javier Mora
- Laboratory of Helminthology, Centro de Investigación en Enfermedades Tropicales, University of Costa Rica, San José, Costa Rica
| | - Alberto Solano-Barquero
- Laboratory of Helminthology, Centro de Investigación en Enfermedades Tropicales, University of Costa Rica, San José, Costa Rica
| | - Guilherme G. Verocai
- Department of Veterinary Pathobiology, Texas A&M University, College of Veterinary Medicine and Biomedical Sciences, College Station, TX, USA
| | - Alicia Rojas
- Laboratory of Helminthology, Centro de Investigación en Enfermedades Tropicales, University of Costa Rica, San José, Costa Rica
- Corresponding author. Twitter icon
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Characterizing parasitic nematode faunas in faeces and soil using DNA metabarcoding. Parasit Vectors 2021; 14:422. [PMID: 34419166 PMCID: PMC8380370 DOI: 10.1186/s13071-021-04935-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 08/06/2021] [Indexed: 01/04/2023] Open
Abstract
Background Gastrointestinal parasitic nematodes can impact fecundity, development, behaviour, and survival in wild vertebrate populations. Conventional monitoring of gastrointestinal parasitic nematodes in wild populations involves morphological identification of eggs, larvae, and adults from faeces or intestinal samples. Adult worms are typically required for species-level identification, meaning intestinal material from dead animals is needed to characterize the nematode community with high taxonomic resolution. DNA metabarcoding of environmental samples is increasingly used for time- and cost-effective, high-throughput biodiversity monitoring of small-bodied organisms, including parasite communities. Here, we evaluate the potential of DNA metabarcoding of faeces and soil samples for non-invasive monitoring of gastrointestinal parasitic nematode communities in a wild ruminant population. Methods Faeces and intestines were collected from a population of wild reindeer, and soil was collected both from areas showing signs of animal congregation, as well as areas with no signs of animal activity. Gastrointestinal parasitic nematode faunas were characterized using traditional morphological methods that involve flotation and sedimentation steps to concentrate nematode biomass, as well as using DNA metabarcoding. DNA metabarcoding was conducted on bulk samples, in addition to samples having undergone sedimentation and flotation treatments. Results DNA metabarcoding and morphological approaches were largely congruent, recovering similar nematode faunas from all samples. However, metabarcoding provided higher-resolution taxonomic data than morphological identification in both faeces and soil samples. Although concentration of nematode biomass by sedimentation or flotation prior to DNA metabarcoding reduced non-target amplification and increased the diversity of sequence variants recovered from each sample, the pretreatments did not improve species detection rates in soil and faeces samples. Conclusions DNA metabarcoding of bulk faeces samples is a non-invasive, time- and cost-effective method for assessing parasitic nematode populations that provides data with comparable taxonomic resolution to morphological methods that depend on parasitological investigations of dead animals. The successful detection of parasitic gastrointestinal nematodes from soils demonstrates the utility of this approach for mapping distribution and occurrences of the free-living stages of gastrointestinal parasitic nematodes. Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-021-04935-8.
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Bourret V, Gutiérrez López R, Melo M, Loiseau C. Metabarcoding options to study eukaryotic endoparasites of birds. Ecol Evol 2021; 11:10821-10833. [PMID: 34429884 PMCID: PMC8366860 DOI: 10.1002/ece3.7748] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 04/30/2021] [Accepted: 05/11/2021] [Indexed: 12/21/2022] Open
Abstract
There is growing interest in the study of avian endoparasite communities, and metabarcoding is a promising approach to complement more conventional or targeted methods. In the case of eukaryotic endoparasites, phylogenetic diversity is extreme, with parasites from 4 kingdoms and 11 phyla documented in birds. We addressed this challenge by comparing different primer sets across 16 samples from 5 bird species. Samples consisted of blood, feces, and controlled mixes with known proportions of bird and nematode DNA. Illumina sequencing revealed that a 28S primer set used in combination with a custom blocking primer allowed detection of various plasmodiid parasites and filarioid nematodes in the blood, coccidia in the feces, as well as two potentially pathogenic fungal groups. When tested on the controlled DNA mixes, these primers also increased the proportion of nematode DNA by over an order of magnitude. An 18S primer set, originally designed to exclude metazoan sequences, was the most effective at reducing the relative number of avian DNA sequences and was the only one to detect Trypanosoma in the blood. Expectedly, however, it did not allow nematode detection and also failed to detect avian malaria parasites. This study shows that a 28S set including a blocking primer allows detection of several major and very diverse bird parasite clades, while reliable amplification of all major parasite groups may require a combination of markers. It helps clarify options for bird parasite metabarcoding, according to priorities in terms of the endoparasite clades and the ecological questions researchers wish to focus on.
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Affiliation(s)
- Vincent Bourret
- CIBIO‐InBIOCentro de Investigação em Biodiversidade e Recursos GenéticosUniversidade do PortoVairãoPortugal
| | - Rafael Gutiérrez López
- CIBIO‐InBIOCentro de Investigação em Biodiversidade e Recursos GenéticosUniversidade do PortoVairãoPortugal
| | - Martim Melo
- CIBIO‐InBIOCentro de Investigação em Biodiversidade e Recursos GenéticosUniversidade do PortoVairãoPortugal
- MHNC‐UP – Natural History and Science Museum of the University of PortoPortoPortugal
- FitzPatrick Institute of African OrnithologyUniversity of Cape TownCape TownSouth Africa
| | - Claire Loiseau
- CIBIO‐InBIOCentro de Investigação em Biodiversidade e Recursos GenéticosUniversidade do PortoVairãoPortugal
- CEFEUniversité de MontpellierCNRSMontpellierFrance
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Halvarsson P, Höglund J. Sheep nemabiome diversity and its response to anthelmintic treatment in Swedish sheep herds. Parasit Vectors 2021; 14:114. [PMID: 33602321 PMCID: PMC7890823 DOI: 10.1186/s13071-021-04602-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 01/23/2021] [Indexed: 11/21/2022] Open
Abstract
Background A novel way to study the species composition and diversity of nematode parasites in livestock is to perform deep sequencing on composite samples containing a mixture of different species. Herein we describe for the first time the nematode community structures (nemabiomes) inhabiting Swedish sheep and how these are/were affected by host age and recent anthelmintic treatments. Methods A total of 158 fecal samples were collected (n = 35 in 2007 and n = 123 in 2013–2016) and cultured from groups of sheep on 61 commercial farms in the south-central part of the country where most animals are grazed. Among the samples, 2 × 44 (56%) were paired collections from the same groups pre- and post-treatment with anthelmintics such as macrocyclic lactones, benzimidazoles or levamisole. Samples were analyzed for their nemabiome using the PacBio platform followed by bioinformatic sequence analysis with SCATA. Species richness and diversity were calculated and analyzed in R. Results Nematode ITS2 sequences were found in all larval culture samples except two, even though the fecal egg counts were below the McMaster threshold in 20 samples. Sequencing yielded, on average, 1008 sequences per sample. In total, 16 operational taxonomical units (OTU), all with ≥ 98 % identity to sequences in the NCBI database, were recognized. The OTUs found represented nematode species of which ten are commonly associated with sheep. Multiple species were identified in all pre-anthelmintic treatment larval culture samples. No effects on nematode diversity were found in relation to host age. On the other hand, recent anthelmintic treatment lowered species richness, especially after use of ivermectin and albendazole. Interestingly, despite zero egg counts after use of levamisole, these samples still contained nematode DNA and especially H. contortus. Conclusions Our findings provide evidence that nemabiome analysis combined with diversity index analysis provides an objective methodology in the study of the efficacy of anthelmintic treatment as both high and low abundant species were detected.![]()
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Affiliation(s)
- Peter Halvarsson
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Section for Parasitology, Uppsala, Sweden.
| | - Johan Höglund
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Section for Parasitology, Uppsala, Sweden
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21
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Wiese JD, Caven AJ, Zarlenga DS, Topliff CL, Kelling CL, Salter J. Gastrointestinal parasites of a reintroduced semi-wild plains bison ( Bison bison bison) herd: Examining effects of demographic variation, deworming treatments, and management strategy. INTERNATIONAL JOURNAL FOR PARASITOLOGY-PARASITES AND WILDLIFE 2021; 14:216-227. [PMID: 33777691 PMCID: PMC7985671 DOI: 10.1016/j.ijppaw.2021.02.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 02/05/2021] [Accepted: 02/06/2021] [Indexed: 11/15/2022]
Abstract
Bison (Bison spp) are being reintroduced into semi-wild, spatially constrained herds across North America and Europe. Herd managers are concerned about gastrointestinal (GI) nematode parasites as they care for the health of their bison. We examine how demographics, grazing location, herd management, and anthelmintic treatments affect the fecal egg counts (FECs) of GI nematodes within a reintroduced Plains bison (Bison bison bison) herd in the Great Plains. Our results suggest that younger bison (<2 years of age) experience higher GI parasite eggs/oocysts per gram (epg/opg) and that some taxa are more prevalent throughout different periods of a bison's early years. Demographic findings suggest that calf and yearling (0–2 yrs age) bison have the highest FECs and that these decline until reaching a low in peak adulthood and thereafter (x > 6 yrs of age). FECs of both Trichuris spp. and particularly Nematodirus spp. were much more abundant, relatively, during the first year of a bison's life. This pattern was also true of Moniezia spp. and Eimeria spp., however, strongyle-type spp. FECs appeared to peak in relative abundance during the second year of life. Our data also indicate that FECs are influenced by differences in land-use histories of pastures previously grazed by cattle or by the proportion of frequent flooding in different pastures. Treatment results suggest that fenbendazole may more effective than moxidectin at lowering FECs of bison over the long-term, and lasting effects of at least one administered anthelmintic treatment. Multiplex PCR assays revealed that American bison share GI nematodes with cattle including: Ostertagia spp., Haemonchus placei, Cooperia onchophora, and Oesophagostomum spp, but did not detect the presence Trichostrongylus columbriformis. Our results may have wider conservation implications for reintroduction efforts of American bison, as well as the endangered European bison (Bison bonasus). Younger plains bison (<2 years of age) are more likely to have higher fecal egg counts of gastrointestinal nematodes. Eimeria spp., Trichuris spp., Moniezia spp., and Nematodirus spp. are more prevalent in plains bison between zero and 1 years of age, while strongyle-type nematodes are more prevalent in bison between 1 and 2 years of age. Both land-use histories and landscape features may influence higher fecal egg counts of gastrointestinal nematodes in plains bison. Plains bison share many of the same type of gastrointestinal parasites found in cattle. Fenbendazole anthelmintic was more effective than moxidectin treatments in reducing fecal egg counts of gastrointestinal parasites in plains bison.
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Affiliation(s)
- Joshua D Wiese
- Platte River Whooping Crane Maintenance Trust, Wood River, NE, 68883, USA
| | - Andrew J Caven
- Platte River Whooping Crane Maintenance Trust, Wood River, NE, 68883, USA
| | - Dante S Zarlenga
- United States Department of Agriculture, Agriculture Research Service, Animal Parasitic Diseases Laboratory, Beltsville, MD, 20705, USA
| | - Christina L Topliff
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Clayton L Kelling
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Jacob Salter
- Platte River Whooping Crane Maintenance Trust, Wood River, NE, 68883, USA
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22
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Kotze AC, Gilleard JS, Doyle SR, Prichard RK. Challenges and opportunities for the adoption of molecular diagnostics for anthelmintic resistance. Int J Parasitol Drugs Drug Resist 2020; 14:264-273. [PMID: 33307336 PMCID: PMC7726450 DOI: 10.1016/j.ijpddr.2020.11.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 11/22/2020] [Accepted: 11/26/2020] [Indexed: 02/06/2023]
Abstract
Anthelmintic resistance is a significant threat to livestock production systems worldwide and is emerging as an important issue in companion animal parasite management. It is also an emerging concern for the control of human soil-transmitted helminths and filaria. An important aspect of managing anthelmintic resistance is the ability to utilise diagnostic tests to detect its emergence at an early stage. In host-parasite systems where resistance is already widespread, diagnostics have a potentially important role in determining those drugs that remain the most effective. The development of molecular diagnostics for anthelmintic resistance is one focus of the Consortium for Anthelmintic Resistance and Susceptibility (CARS) group. The present paper reflects discussions of this issue that occurred at the most recent meeting of the group in Wisconsin, USA, in July 2019. We compare molecular resistance diagnostics with in vivo and in vitro phenotypic methods, and highlight the advantages and disadvantages of each. We assess whether our knowledge on the identity of molecular markers for resistance towards the different drug classes is sufficient to provide some expectation that molecular tests for field use may be available in the short-to-medium term. We describe some practical aspects of such tests and how our current capabilities compare to the requirements of an 'ideal' test. Finally, we describe examples of drug class/parasite species interactions that provide the best opportunity for commercial use of molecular tests in the near future. We argue that while such prototype tests may not satisfy the requirements of an 'ideal' test, their potential to provide significant advances over currently-used phenotypic methods warrants their development as field diagnostics.
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Affiliation(s)
- Andrew C. Kotze
- CSIRO Agriculture and Food, St. Lucia, Brisbane, 4072, QLD, Australia,Corresponding author. , CSIRO Agriculture and Food, St. Lucia, Brisbane, 4072, QLD, Australia.
| | - John S. Gilleard
- Department of Comparative Biology and Experimental Medicine, Host-Parasite Interactions Program, University of Calgary, Calgary, Alberta, T2N 4N1, Canada
| | - Stephen R. Doyle
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SA, UK
| | - Roger K. Prichard
- Institute of Parasitology, McGill University, Sainte Anne-de-Bellevue, QC, H9X 3V9, Canada
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23
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Queiroz C, Levy M, Avramenko R, Redman E, Kearns K, Swain L, Silas H, Uehlinger F, Gilleard JS. The use of ITS-2 rDNA nemabiome metabarcoding to enhance anthelmintic resistance diagnosis and surveillance of ovine gastrointestinal nematodes. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2020; 14:105-117. [PMID: 33027723 PMCID: PMC7548992 DOI: 10.1016/j.ijpddr.2020.09.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 09/16/2020] [Accepted: 09/16/2020] [Indexed: 12/02/2022]
Abstract
A lack of quantitative information on the species composition of parasite communities present in fecal samples is a major limiting factor for the sensitivity, accuracy and interpretation of the diagnostic tests commonly used to assess anthelmintic efficacy and resistance. In this paper, we investigate the ability of ITS-2 rDNA nemabiome metabarcoding to enhance fecal egg count reduction testing by providing information on the effect of drug treatments on individual parasite species. Application of ITS-2 rDNA nemabiome metabarcoding to fecal samples from ewes from over 90 flocks across western Canada revealed high gastrointestinal nematode infection intensities in many flocks with Haemonchus contortus being the most abundant species followed by Teladorsagia circumcincta and then Trichostrongylus colubriformis. Integration of ITS-2 rDNA nemabiome metabarcoding with pre- and post-treatment fecal egg counting revealed consistently poor efficacy of producer-applied ivermectin and benzimidazole treatments against H. contortus, but much better efficacy against T. circumcincta and T. colubriformis, except for in a small number of flocks. Integration of nemabiome ITS-2 rDNA metabarcoding with Fecal Egg Count Reduction Tests (FECRT), undertaken on farm visits, confirmed that ivermectin and fenbendazole resistance is widespread in H. contortus but is currently less common in T. circumcincta and T. colubriformis in western Canada. FECRT/nemabiome testing did not detect moxidectin resistance in any GIN species but suggested the early emergence of levamisole resistance specifically in T. circumcincta. It also revealed that although poor efficacy to closantel was relatively common, based on total fecal egg counts, this was due to its narrow spectrum of activity rather than the emergence of anthelmintic resistance. This study illustrates the value of ITS-2 rDNA nemabiome metabarcoding to improve fecal egg count resistance testing, perform large-scale anthelmintic resistance surveillance and direct more targeted rational anthelmintic use. Nemabiome metabarcoding in anthelmintic resistance diagnostics and surveillance. Producer-applied treatment results were consistent with controlled FECRT. Widespread BZ and IVM resistance in H. contortus in western Canada. Only sporadic BZ and IVM resistance T. circumcincta and T. colubriformis. Early levamisole resistance in T. circumcincta, closantel resistance not prevalent.
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Affiliation(s)
- Camila Queiroz
- Department of Comparative Medicine and Experimental Biology, Host-Parasite Interactions Program, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, 3330, Canada Hospital Dr T2N4N1, Canada
| | - Michel Levy
- Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, 3330, Canada Hospital Dr T2N4N1, Canada
| | - Russell Avramenko
- Department of Comparative Medicine and Experimental Biology, Host-Parasite Interactions Program, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, 3330, Canada Hospital Dr T2N4N1, Canada
| | - Elizabeth Redman
- Department of Comparative Medicine and Experimental Biology, Host-Parasite Interactions Program, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, 3330, Canada Hospital Dr T2N4N1, Canada
| | - Kelsey Kearns
- Department of Comparative Medicine and Experimental Biology, Host-Parasite Interactions Program, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, 3330, Canada Hospital Dr T2N4N1, Canada
| | - Lana Swain
- Department of Comparative Medicine and Experimental Biology, Host-Parasite Interactions Program, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, 3330, Canada Hospital Dr T2N4N1, Canada
| | - Haley Silas
- Department of Comparative Medicine and Experimental Biology, Host-Parasite Interactions Program, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, 3330, Canada Hospital Dr T2N4N1, Canada
| | - Fabienne Uehlinger
- Department of Large Animal Clinical Sciences, University of Saskatchewan 52 Campus Dr S7N5B4
| | - John S Gilleard
- Department of Comparative Medicine and Experimental Biology, Host-Parasite Interactions Program, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, 3330, Canada Hospital Dr T2N4N1, Canada.
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Abstract
Internal parasites are a major concern in livestock production because they can impact the health and well-being of animals clinically and subclinically, and ultimately cause significant production loss. Among these internal parasites are nematodes, tapeworms, flukes, and coccidian protozoans. This review focuses on the diagnostic tests that are routinely performed by veterinarians and diagnostic laboratories, but also highlights recently developed tools that may improve diagnostic capabilities, including molecular and immunodiagnostic tests. Overall, diagnostic tests for parasites of livestock are an integral part of health management practices, and for assessing individual animal and herd health.
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25
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Abstract
Helminth parasitology is an important discipline, which poses often unique technical challenges. One challenge is that helminth parasites, particularly those in humans, are often difficult to obtain alive and in sufficient quantities for study; another is the challenge of studying these organisms in vitro – no helminth parasite life cycle has been fully recapitulated outside of a host. Arguably, the key issue retarding progress in helminth parasitology has been a lack of experimental tools and resources, certainly relative to the riches that have driven many parasitologists to adopt free-living model organisms as surrogate systems. In response to these needs, the past 10–12 years have seen the beginnings of helminth parasitology's journey into the ‘omics’ era, with the release of abundant sequencing resources, and the functional genomics tools with which to test biological hypotheses. To reflect this progress, the 2019 Autumn Symposium of the British Society for Parasitology was held in Queen's University Belfast on the topic of ‘post-genomic progress in helminth parasitology’. This issue presents examples of the current state of play in the field, while this editorial summarizes how genomic datasets and functional genomic tools have stimulated impressive recent progress in our understanding of parasite biology.
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Assessing anthelmintic resistance risk in the post-genomic era: a proof-of-concept study assessing the potential for widespread benzimidazole-resistant gastrointestinal nematodes in North American cattle and bison. Parasitology 2020; 147:897-906. [PMID: 32138794 PMCID: PMC7391874 DOI: 10.1017/s0031182020000426] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
As genomic research continues to improve our understanding of the genetics of anthelmintic drug resistance, the revolution in DNA sequencing technologies will provide increasing opportunities for large-scale surveillance for the emergence of drug resistance. In most countries, parasite control in cattle and bison has mainly depended on pour-on macrocyclic lactone formulations resulting in widespread ivermectin resistance. Consequently, there is an increased interest in using benzimidazole drugs which have been used comparatively little in cattle and bison in recent years. This situation, together with our understanding of benzimidazole resistance genetics, provides a practical opportunity to use deep-amplicon sequencing to assess the risk of drug resistance emergence. In this paper, we use deep-amplicon sequencing to scan for those mutations in the isotype-1 β-tubulin gene previously associated with benzimidazole resistance in many trichostrongylid nematode species. We found that several of these mutations occur at low frequency in many cattle and bison parasite populations in North America, suggesting increased use of benzimidazole drugs in cattle has the potential to result in widespread emergence of resistance in multiple parasite species. This work illustrates a post-genomic approach to large-scale surveillance of early emergence of anthelmintic resistance in the field.
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27
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Dos Santos MC, Amarante MRV, Amarante AFT. Is there competition between Haemonchus contortus and Haemonchus placei in a pasture grazed by only sheep? Vet Parasitol 2020; 279:109054. [PMID: 32065932 DOI: 10.1016/j.vetpar.2020.109054] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 02/03/2020] [Accepted: 02/06/2020] [Indexed: 11/20/2022]
Abstract
This study aimed to evaluate the dynamics of Haemonchus contortus and Haemonchus placei infections and hybridization between these species in grazing sheep without contact with cattle. On January 14, 2014, sixteen young sheep were infected with 4000 infective H. placei third-stage larvae L3; 11 days later, another group n = 16 was infected with 4000 H. contortus L3. The establishment rates of H. contortus and H. placei L3 were, on average, 61.6 % and 56.8 %, respectively, in the permanent sheep. After the establishment of patent infections, all permanent sheep were allocated together in the same clean pasture where they grazed for the next 12 months. Euthanasia of a sample of the permanent sheep was performed every three months: in May, August, November and February. Two weeks before the sheep were removed for euthanasia, 2 worm-free tracer sheep were introduced to the pasture to evaluate the larval population in the field. The tracer sheep grazed alongside the permanent sheep for 2 weeks. Then, they were housed indoors for 20 days; at the end of this period, they were euthanized. Parasites were recovered from the permanent and tracer sheep and identified using morphological and molecular techniques. A total of 432 worms (from permanent and tracer animals) were analyzed by PCR using species-specific primer pairs. Of these specimens, only two (0.46 %) male worms were identified as hybrids: one was recovered from a permanent animal euthanized in August and the other from a tracer sheep that grazed in May. The last detection of adult H. placei worms occurred in sheep euthanized in May (approximately 3.5 months after the beginning of the grazing period). The morphological evaluation of the L3 produced in fecal cultures showed that H. placei were progressively replaced by H. contortus populations starting in March. The last trace of H. placei L3 was found in August, when a small percentage (0.5 %) of infective larvae with H. placei morphology was identified in a fecal culture. In conclusion, hybridization between H. contortus and H. placei can occur in the field during coinfection. It was demonstrated that H. placei established successfully in artificially infected worm-free sheep; however, with concomitant natural reinfection with H. contortus, the H. placei population showed a rapid decrease and was eliminated within a few months in an environment without cattle.
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Affiliation(s)
- Michelle C Dos Santos
- Universidade Estadual Paulista (UNESP), Instituto de Biociências, Botucatu, SP, Brazil
| | - Mônica R V Amarante
- Universidade Estadual Paulista (UNESP), Instituto de Biociências, Botucatu, SP, Brazil
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Molecular method for the semiquantitative identification of gastrointestinal nematodes in domestic ruminants. Parasitol Res 2019; 119:529-543. [PMID: 31834492 DOI: 10.1007/s00436-019-06569-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 11/26/2019] [Indexed: 12/27/2022]
Abstract
Standard diagnostic methods currently in use for the identification of helminth infections in ruminants are based on the morphological analysis of immature and adult stages of parasites. This paper describes a method for the semiquantitative identification of nematodes, mainly Trichostrongyloidea, at species-level resolution. The method is based on amplification and fragment analysis followed by minisequencing of the ITS-2 region (internal transcribed spacer 2) of the ribosomal DNA of parasite eggs or larvae. This method allows for the identification of seven genera (Chabertia, Cooperia, Haemonchus, Oesophagostomum, Ostertagia, Teladorsagia, and Trichostrongylus) and 12 species (Chabertia ovina, Cooperia curticei, Cooperia punctata, Cooperia oncophora/Cooperia surnabada, Haemonchus contortus, Haemonchus placei, Haemonchus longistipes, Oesophagostomum asperum, Oesophagostomum radiatum, Ostertagia ostertagi, Trichostrongylus axei, and Trichostrongylus colubriformis) of infectious nematodes of domestic ruminants. The concordance between the morphological and molecular analyses in the detection of genera ranged from 0.84 to 0.99, suggesting the proposed detection method is specific, semiquantitative, less laborious, and highly cost-efficient.
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Validation of ITS-2 rDNA nemabiome sequencing for ovine gastrointestinal nematodes and its application to a large scale survey of UK sheep farms. Vet Parasitol 2019; 275:108933. [PMID: 31606485 DOI: 10.1016/j.vetpar.2019.108933] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 09/29/2019] [Accepted: 09/30/2019] [Indexed: 02/08/2023]
Abstract
We have validated ITS-2 rDNA nemabiome next-generation amplicon sequencing to determine relative species abundance of gastrointestinal nematode species in ovine fecal samples. In order to determine species representation biases, ITS-2 rDNA amplicon sequencing was applied to mock communities or field populations with known proportions of L3 for eight of the major ovine gastrointestinal nematode species: Teladorsagia circumcincta, Trichostrongylus vitrinus, Haemonchus contortus, Cooperia curticei, Trichostrongylus axei, Trichostrongylus colubriformis, Chabertia ovina and Oesophagostumum venulosum. Correction factors, calculated from this data, were shown to reduce species representation biases when applied to an independent set of field samples of known composition. We compared ITS-2 rDNA amplicon sequencing data that was generated from harvested eggs, freshly hatched L1 or L3 larvae following fecal culture and no statistically significant differences were found for the more abundant parasite species. We then applied the validated ITS-2 rDNA nemabiome amplicon sequencing assay to a set of archived L1 gastrointestinal nematode populations, collected in 2008 from fecal samples from 93 groups of 20 ewes and 61 groups of 20 lambs derived from 99 UK sheep farms. The presence of the major gastrointestinal nematode species had previously been determined on this large sample set by species-specific PCR. We show how the ITS-2rDNA amplicon sequencing data provided much more detailed information on species abundance than the previous species-specific PCR. This new data represents the most comprehensive overview of the relative abundance of the major gastrointestinal nematode species across UK sheep farms to date. Substantial variance in the relative abundance of both T. circumcincta and T. vitrinus between farms was revealed with the former species being of statistically significantly higher abundance in all three regions sampled (England, Scotland and Wales). The data also revealed that the relative abundance of T. circumcinta was statistically significantly higher in ewes than in lambs with the opposite pattern being the case for T. vitrinus. The nemabiome sequencing data also clearly illustrated the sporadic nature and skewed distribution of H. controtus across UK sheep farms as well as a higher relative abundance on farms from England compared to Wales and Scotland. The nemabiome survey also provides the first widescale data on the relative abundance of the two major large intestinal nematodes C. ovina and O. venulosum. This work validates ITS-2 rDNA nemabiome sequencing for use in sheep and illustrates the power of the approach for large scale surveillance of ovine gastrointestinal nematodes.
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