Detection of bovine immunodeficiency-like virus infection in experimentally infected calves

Detection of BIV virus infection by serological means, PCR and virus isolation in experimentally infected calves is described. Viral sequences were specifically detected by PCR in peripheral blood mononuclear cells (PBMCs), with primer systems located in the gag, pot and tat regions of the viral genome. An enzyme-linked oligosorbent assay (ELOSA) in microtiter plates is described; for the detection of PCR products, the sensitivity of which was shown to be comparable to that of membrane hybridization detection. Serological response of the animals against the BTV p26 protein was shown, using a recombinant fusion protein ((His)(6)p26) expressed in E. coli and purified by metal affinity chromatography, in ELISA and Western blot studies. The presence of infectious virus was demonstrated by its rescue, by virus isolation in cell cultures, from PBMCs during a one year follow-up.