Adaptation of an indirect enzyme-linked immunosorbent assay by purified gp51SU for detection of antibodies to bovine leukemia virus

The objective of this study was to compare an indirect ELISA, based on a purified 60 kDa envelope glycoprotein (gp51SU), with a Pourquire indirect ELISA for the detection of antibodies to the bovine leukemia virus. For conducting this research, 340 serum samples were collected from two different breeds of cows (Sarabi and Holestin) in different herds. Commercial ELISA revealed positive results in 17 (7%) Holstein cows. An appropriate ELISAcut-off was determined by receiver operating curve (ROC) analysis in comparison with commercial indirect ELISA. Results showed a relative sensitivity and specificity of 97% and 92%, respectively, for a cut-off value of 0.34 in the domestic ELISA. In conclusion, the results of the present study showed that domestic developed kit can be used for diagnosis of bovine leukemia virus with appropriate sensitivity and specificity. In addition, a comparison of the results from a native breed, Sarabi, with Holstein showed that there was no significant (P>0.05) difference in the frequency of infection with BLV between the two breeds.