Evaluation of pre-erythrocytic stage recombinant proteins of Theileria annulata for early diagnosis of bovine tropical theileriosis in Indian cattle

Abstract

A study was carried out to evaluate 2 pre-erythrocytic recombinant proteins for the diagnosis of bovine tropical theileriosis during the initial phase of the disease. Theileria annulata surface protein (TaSP) and the C terminal region of SPAG–1 were cloned and expressed as fusion with thioredoxine in E. coli. The proteins were purified to near homogeneity using Ni-NTA agarose affinity chromatography. In ELISA, recombinant TaSP (rTaSP) was able to detect antibodies from 7 to 14 days onward in all the 4 experimental bovine calves while no significant results were obtained with rSPAG–1 (C-terminus). rTaSP also showed higher sensitivity than crude piroplasmic antigen in 50 field sera by ELISA. In addition, rTaSP did not show any cross reactivity with Babesia bigemina and Trypanosoma evansi positive sera. The present findings indicated rTaSP as a potential molecule for serodiagnosis of T. annulata.