Diagnosis of tropical bovine theileriosis by ELISA with recombinant merozoite surface protein of Theileria annulata (Tams1).

Theileria annulata merozoite surface protein (Tams1) and native soluble piroplasm antigen of an Indian isolate of T. annulata were used to optimize an enzyme linked immunosorbent assay (ELISA) to detect anti-Theileria antibodies in cross-bred cattle experimentally infected with sporozoites or immunized with macroschizonts of the homologous strain of the parasite. The recombinant protein has showed similar antibody titre when compared with the sonicated merozoite/piroplasm antigen in an ELISA. IFAT was used as a reference test. In 56 sera of apparently healthy cattle collected from endemic area, ELISA showed positive antibody response in 29 samples with Tams1 whereas the soluble piroplasm antigen reacted positively with 34 samples and also with sera of cattle positive for Babesia bigemina. Microscopical detection of piroplasms was possible in the blood smears of 17 animals which were serologically positive in both native and recombinant antigens.