AUTHOR=Altay Kursat , Erol Ufuk , Sahin Omer Faruk , Ulucesme Mehmet Can , Aytmirzakizi Ayperi , Aktas Munir 

TITLE=Survey of tick-borne pathogens in grazing horses in Kyrgyzstan: phylogenetic analysis, genetic diversity, and prevalence of Theileria equi

JOURNAL=Frontiers in Veterinary Science

VOLUME=11

YEAR=2024

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2024.1359974

DOI=10.3389/fvets.2024.1359974

ISSN=2297-1769

ABSTRACT=<sec><title>Introduction</title><p>Tick-borne pathogens (TBP) are an important group of organisms that can affect animals and humans all over the world. Equine piroplasmosis (EP), caused by <italic>Theileria equi</italic> and <italic>Babesia caballi</italic>, is considered one of the most important tick-borne diseases and can cause significant clinical symptoms and mortality in horses. Moreover, EP plays a restrictive role in international horse traditions and transportation. Although these species can cause similar symptoms, there are different 18S rRNA genotypes of <italic>T. equi</italic> (five genotypes) and <italic>B. caballi</italic> (three genotypes). Besides piroplasma species, <italic>Anaplasma</italic> and hemotropic mycoplasmas (HM) are known as other important tick-borne pathogens reported in horses.</p></sec><sec><title>Methods</title><p>In this study, we investigated the presence, prevalence, genetic diversity, and phylogenetic analyses of TBPs using PCRs and DNA sequencing in grazing horses in Kyrgyzstan. For these purposes, a total of 311 blood samples were collected from Chuy, Issyk-Kul, Naryn, Osh, Talas, and Jalal-Abad.</p></sec><sec><title>Results</title><p>DNA amplification of TBP revealed that 23 (7.40%) out of 311 samples were found to be positive for <italic>T. equi</italic>. However, <italic>B. caballi</italic>, HM, <italic>A. phagocytophilum</italic>, and <italic>A. capra</italic> were not detected in this study. The infection rate of <italic>T. equi</italic> was higher in males (8.11%) than in females (6.35%) (<italic>p</italic>=0.2880) and in those older than 5 years (9.02%) than in the 1-4 age group (6.35%) (<italic>p</italic>=0.1950). Phylogenetic analysis of 18S <italic>rRNA</italic> revealed that A and E genotypes of <italic>T. equi</italic> have circulated in grazing horses in Kyrgyzstan.</p></sec><sec><title>Discussion</title><p>Information about the genetic diversity of <italic>T. equi</italic> is important for understanding the population dynamics of the species and developing effective control strategies against this pathogen. This is the first molecular investigation of <italic>A. capra</italic> in horses in Kyrgyzstan. Although this pathogen has been detected in different hosts in Kyrgyzstan, it was not detected in this study. However, considering the wide host spectrum of <italic>A. capra</italic>, it is thought that more large-scale studies are needed to understand the effect of horses on the epidemiology of this pathogen.</p></sec>