Diagnosis and quantification of Theileria sergenti using TaqMan PCR.

Theileria sergenti is the causative agent of persistent theileriosis in cattle. The ubiquitous infection of theileiriosis causes chronic anemia and fever in cattle, especially in exogenous cattle. In this study, we applied real-time polymerase chain reaction (PCR) for the diagnosis and quantification of parasite using specific primers for 33 kDa gene fragment of T. sergenti. Comparison of TaqMan PCR with traditional microscopic method, Giemsa's staining, on blood collected from cattle revealed the specificity up to 0.00005% of parasitemia to traditional diagnosis. In addition, it was found that this method can estimate the relative status of infection among herds. The results of present study showed that this method is not only applicable to detect the chronic infection of Theileria, but also effective in evaluation on parasitemia status of cattle, thus it can be used in monitoring the health status in field.