Serological evidence of bovine immunodeficiency virus infection in cattle and buffalo through use of recombinant capsid (P26) protein based immunoassay

A 750-bp DNA fragment of the gag gene, coding the p26 capsid protein of bovine immunodeficiency virus (BIV), was cloned in pQE32 vector and expressed as 6X His tagged fusion protein in E. coli. Using the purified capsid protein, an indirect ELISA was standardized to test sera of cattle and buffalo for BIV antibody. Out of the 672 animals tested, 162 were positive and 510 were negative by indirect ELISA, giving an overall prevalence of 24% in India. In the species-wise break up, 121 (23.5%) out of 516 cattle tested and 41 (26%) buffalo out of 156 buffalo tested were positive for BIV antibodies.