Development of a Specific PCR Assay for Theileria sp. Yokoyama and Assessment of Its Potential to Cause Anemia in Cattle.

The clinical implications of Theileria sp. Yokoyama, a recently identified Theileria species in cattle, remain uncertain. The objective of the present study was to evaluate the anemia status in cattle infected with Theileria sp. Yokoyama. Blood samples were collected from 206 cattle across seven Veterinary Ranges in Sri Lanka and analyzed for red blood cell (RBC) indices, including hemoglobin concentration, hematocrit, and RBC counts. Additionally, DNA was extracted from the samples and screened with a newly developed Theileria sp. Yokoyama-specific PCR assay targeting the cytochrome b gene. The PCR results revealed that 60 (29.1%) of the surveyed cattle tested positive for Theileria sp. Yokoyama, with 47 (78.3%) of them being co-infected with other hemopathogen species. Our findings revealed that the cattle breeds, management systems, and tick infestations are potential risk factors for the Theileria sp. Yokoyama infection. Next, we evaluated the anemia status among the surveyed cattle based on the RBC indices. We found that all non-infected cattle were non-anemic. By contrast, anemia was observed in 15 Theileria sp. Yokoyama-infected cattle, including 3 singly infected (anemia rate 3/13, 23.1%) and 12 co-infected cattle (12/47, 25.5%). Our findings suggest that Theileria sp. Yokoyama causes anemia in infected cattle.

Molecular prevalence and genotypic diversity of Theileria equi and Babesia caballi infecting horses in Kyrgyzstan.

Equine piroplasmosis is caused by Theileria equi and Babesia caballi, which are hemoprotozoan parasites. Understanding the epidemiology and genotypes of T. equi and B. caballi is crucial for developing effective control strategies in endemic countries. However, the endemic status of these two parasite species remains uncertain in Kyrgyzstan due to lack of surveys. Our study, therefore, aimed to detect T. equi and B. caballi infections in Kyrgyzstan and identify their genotypes. Blood samples were collected from 226 horses across all seven provinces of Kyrgyzstan, namely Chuy, Issyk-Kul, Naryn, Talas, Jalal-Abad, Osh, and Batken. These blood samples were subjected to DNA extraction, followed by specific PCR assays targeting T. equi and B. caballi. We found that 56 (24.8%, confidence interval (CI): 19.6-30.8%) and 7 (3.1%, CI: 1.5-6.3%) of the tested horses were positive for T. equi and B. caballi infections, respectively. Theileria equi was detected in all surveyed provinces, whereas B. caballi was found in five provinces, except for Talas and Osh. Subsequent genotype-specific PCR assays showed that T. equi-positive horses harbored all five genotypes: A, B, C (also known as Theileria haneyi), D, and E. On the other hand, phylogenetic analysis of B. caballi rap-1 sequences detected the genotypes A and B1. The prevalence of T. equi and B. caballi suggests a potential risk of clinical equine piroplasmosis among horses in Kyrgyzstan, and the observed genotypic diversity underscores the challenges in managing the disease. Our findings emphasize the need for comprehensive control measures to effectively address equine piroplasmosis in Kyrgyzstan.