Molecular detection of Theileria annulata infection in cattle by conventional PCR and quantitative real time PCR in India.

Theileria annulata (T. annulata) is a tick-borne apicomplexan parasite that affects bovine. It is endemic in many tropical and subtropics areas, including Odisha, India. The objective of this study is to identify T. annulata infection in the peripheral blood of cattle as a biological sample by conventional PCR (cPCR) and quantitative PCR (qPCR). The phylogenetic analysis was done using the T. annulata merozoite surface antigen (Tams 1) gene. Out of 552 samples of examined blood smears by microscopy, 454 (82.24%) animals were positive for Theileria species. Out of 454 samples, 96 samples were further examined by both cPCR and qPCR, 52 samples (54.16%) were found positive for T. annulata in both PCR methodologies. Phylogenetic analysis revealed that T. annulata Odisha isolate was closely related to T. annulata Uttarakhand, India isolate (KM061799) and Hyderabad, India isolate (MK034702) with Nucleotide sequence identity 95.36%, 95.25%, respectively. This is the first study to detect T. annulata by qPCR in Odisha and supported that both PCR techniques were equally effective for the detection of Tams 1 gene of T. annulata in cattle's blood. © Indian Society for Parasitology 2020.