Molecular species determination of cyathostomins from horses in Ireland.

The research investigates the types of cyathostomins, a major equine parasite, present in horses in Ireland and aims to improve the understanding of these parasites’ epidemiology and pathogenicity. DNA was extracted and sequenced from adult worms found within horses post-mortem in order to identify species prevalence and abundance, and taxonomic relationships and community composition were also recorded.

Background

• Cyathostomins are a significant type of parasite that impacts horses worldwide. These parasites can have both chronic and acute pathological effects, and are a particular concern in Ireland due to the year-round rainfall and temperate climate conditions contributing to infectious environments for grazing animals.
• The parasites can place a strain on our comprehension of the host-parasite dynamics, parasite epidemiology, and their pathogenicity due to the occurrence of mixed infections with multiple species of cyathostomins.

Methodology

• The researchers studied intestinal parasites from eleven adult horses that had died between August 2018 and June 2020. They focused specifically on parasites found in the caecum, right ventral colon, and left dorsal colon.
• The researchers used molecular genetic techniques to analyze the parasites. DNA was extracted and the ITS-2 genomic region was amplified and sequenced. These sequences were then compared to known sequences of different cyathostomin species, using both BLAST and the software IDTAXA to assign taxonomic identities to the parasite samples.

Key Findings

• The researchers found that the occurrence of cyathostomins in different geographical regions did not show considerable differences – a finding consistent with previous studies.
• The study confirmed the difficulties that arise in differentiating between two species of cyathostomins – Cylicostephanus calicatus and Coronocyclus coronatus – when based only on ITS-2 sequences. The result established the need for further research methods or techniques to conclusively differentiate between these species.
• A better understanding of the variety, prevalence, and phylogenetic relationships of cyathostomins in horses in Ireland was achieved, which adds to the global understanding of this major equine parasite.