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

The clinical implications of sp. Yokoyama, a recently identified species in cattle, remain uncertain. The objective of the present study was to evaluate the anemia status in cattle infected with 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 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 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 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 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 sp. Yokoyama causes anemia in infected cattle.