Faecal egg counts and nemabiome metabarcoding highlight the genomic complexity of equine cyathostomin communities and provide insight into their dynamics in a Scottish native pony herd.
Abstract: Understanding the composition of gastrointestinal nematode communities may help to mitigate or exploit parasite adaptations within their host. We have used nemabiome deep amplicon sequencing of internal transcribed spacer-2 (ITS-2) ribosomal DNA to describe the temporal and host species composition of gastrointestinal nematode communities following sampling of six Scottish ponies across 57 months. In the absence of parasite control, each horse showed seasonal trends of increases and decreases in faecal egg counts, consistent with the epidemiology of equine strongylid parasites, however, the composition of parasites within individuals changed over time. Sixteen presumptive strongylid species were identified in each of the horses, 13 of which were distributed in a complex clade together with small numbers of amplicon sequences which could not be classified beyond the Cyathostominae subfamily level. Egg shedding of seven trichostrongylid species, which had previously been identified in co-grazed Soay sheep, was identified during the early spring. Faecal egg counts and the percentage of amplicon sequences assigned to each gastrointestinal nematode species were combined to describe their relative abundance across both host and time. Significant differences in species diversity between horses and between months were observed, being greatest from March to May and least from October to December. The magnitude of the individual horse effect varied between months and, conversely, the magnitude of the seasonal effect varied between individual horses. The most abundant gastrointestinal nematode in each of the horses was Cylicostephanus longibursatus (46.6% overall), while the abundance of the other strongylid species varied between horses and relative to each other. Patent C. longibursatus infections over the winter months might represent a genetic adaptation towards longer adult worm survival, or a lower rate of developmental arrest in the autumn. This study provides insight into highly complex phylogenetic relationships between closely related cyathostomin species; and describes the dynamics of egg shedding and pasture contamination of co-infecting equine gastrointestinal nematode communities. The results could be applied to determine how climatic and management factors affect the equilibrium between hosts and their parasites, and to inform the development of sustainable gastrointestinal nematode control strategies for different host species.
Copyright © 2022 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.
Publication Date: 2022-10-05 PubMed ID: 36208676DOI: 10.1016/j.ijpara.2022.08.002Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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The study explores the complexity and dynamics of gastrointestinal nematode communities in a group of Scottish ponies over a period of 57 months. Using nemabiome deep amplicon sequencing and faecal egg counts, the researchers identified seasonal variations and significant differences in species diversity among the ponies. This research could help in understanding how external factors affect the relationship between hosts and parasites and contribute to the development of comprehensive control strategies.
Understanding Nematode Communities
- The researchers undertook primary study on gastrointestinal nematode communities within six Scottish ponies. The goal was to understand how these communities transform over a long period (57 months in this study) and how these changes affect host’s health and their overall ability to parry parasites.
- Utilizing nemabiome deep amplicon sequencing of internal transcribed spacer-2 (ITS-2) ribosomal DNA, the team described the chronological and host-specific composition of these nematode communities.
- The team identified sixteen unique strongylid species in each pony. Such species differentiation suggests a high level of phylogenetic complexity within the gastrointestinal environment.
Seasonal Trends and Variation in Nematode Communities
- The study observed recurring trends indicating variations in faecal egg counts, consistent with the epidemiology of equine strongylid parasites.
- The ponies exhibited significant differences in species diversity, with the greatest diversity observed from March to May and the least from October to December. These findings suggest that the gastrointestinal nematode community in horses is subject to seasonal changes.
- The individual and seasonal effects fluctuated; the magnitude of the horse-specific effect varied with the month, and vice-versa, demonstrating that both intrinsic and extrinsic factors contribute to the nematode community composition.
Implications of the Study
- The research offers insight into the complex phylogenetic relationships between closely related cyathostomin species and provides valuable data on their seasonal dynamics.
- Understanding the variations in nematode communities and factors influencing their development may help in determining how climatic and managerial factors affect the host-parasite equilibrium.
- These findings could guide the development of sustainable gastrointestinal nematode control strategies for diverse host species, thereby improving animal health and reducing the economic impact of parasitic diseases.
Cite This Article
APA
Sargison N, Chambers A, Chaudhry U, Costa Júnior L, Doyle SR, Ehimiyein A, Evans M, Jennings A, Kelly R, Sargison F, Sinclair M, Zahid O.
(2022).
Faecal egg counts and nemabiome metabarcoding highlight the genomic complexity of equine cyathostomin communities and provide insight into their dynamics in a Scottish native pony herd.
Int J Parasitol, 52(12), 763-774.
https://doi.org/10.1016/j.ijpara.2022.08.002 Publication
Researcher Affiliations
- University of Edinburgh, Royal (Dick) School of Veterinary Studies and The Roslin Institute, Easter Bush Veterinary Centre, Roslin, Midlothian EH25 9RG, UK. Electronic address: neil.sargison@ed.ac.uk.
- University of Edinburgh, Royal (Dick) School of Veterinary Studies and The Roslin Institute, Easter Bush Veterinary Centre, Roslin, Midlothian EH25 9RG, UK.
- University of Edinburgh, Royal (Dick) School of Veterinary Studies and The Roslin Institute, Easter Bush Veterinary Centre, Roslin, Midlothian EH25 9RG, UK.
- Federal University of Maranhão, Pathology Department, São Luís, Maranhão, Brazil.
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SA, UK.
- University of Edinburgh, Royal (Dick) School of Veterinary Studies and The Roslin Institute, Easter Bush Veterinary Centre, Roslin, Midlothian EH25 9RG, UK.
- University of Edinburgh, Royal (Dick) School of Veterinary Studies and The Roslin Institute, Easter Bush Veterinary Centre, Roslin, Midlothian EH25 9RG, UK.
- University of Edinburgh, Royal (Dick) School of Veterinary Studies and The Roslin Institute, Easter Bush Veterinary Centre, Roslin, Midlothian EH25 9RG, UK.
- University of Edinburgh, Royal (Dick) School of Veterinary Studies and The Roslin Institute, Easter Bush Veterinary Centre, Roslin, Midlothian EH25 9RG, UK.
- University of Edinburgh, Royal (Dick) School of Veterinary Studies and The Roslin Institute, Easter Bush Veterinary Centre, Roslin, Midlothian EH25 9RG, UK.
- Achindarroch Farm, Duror, Argyll, PA38 4BS, UK.
- University of Edinburgh, Royal (Dick) School of Veterinary Studies and The Roslin Institute, Easter Bush Veterinary Centre, Roslin, Midlothian EH25 9RG, UK.
MeSH Terms
- Sheep
- Horses
- Animals
- Parasite Egg Count / veterinary
- Phylogeny
- Strongyloidea / genetics
- Feces / parasitology
- Nematoda
- Genomics
- Scotland
Grant Funding
- MR/T020733/1 / Medical Research Council
- Biotechnology and Biological Sciences Research Council
Citations
This article has been cited 15 times.- Courtot É, Boisseau M, Dhorne-Pollet S, Serreau D, Gesbert A, Reigner F, Basiaga M, Kuzmina T, Lluch J, Annonay G, Kuchly C, Diekmann I, Krücken J, von Samson-Himmelstjerna G, Mach N, Sallé G. Comparison of two molecular barcodes for the study of equine strongylid communities with amplicon sequencing. PeerJ 2023;11:e15124.
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- Mohtasebi S, Ahn S, Karimi M, Saberi M, Gilleard JS, Poissant J. Enhanced detection of equine strongyles: Insights from morphological and nemabiome metabarcoding approaches in northern Iran. Equine Vet J 2026 Mar;58(2):508-522.
- Jamshidpour R, Nabavi R, Moadab H, Rezaie F, Chale AC, Sargison N. Evaluation of Benzimidazole Resistance in Equine Cyathostomins in the Kermanshah Province of Iran Using Coprological Analysis and Allele-Specific PCR. Iran J Parasitol 2025 Jul-Sep;20(3):389-399.
- Zahid O, Chaudhry U, Sargison ND. Development and field application of metabarcoding-adapted mt-ND4 markers shows substantial gene flow and varying local pressures on Haemonchus contortus and Teladorsagia circumcincta populations in the UK. PLoS One 2025;20(7):e0327254.
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