Development of a recombinant σB protein based dot-ELISA for the diagnosis of avian reovirus (ARV)

Avian reovirus (ARV) causes significant economic losses to the poultry industry worldwide. The ARV proteins fall into three different classes based on their sizes:λ (large); μ (medium) and σ (small). σB, an outer capsid protein of the ARV contains group specific neutralizing epitopes and induces strong immune response in naturally infected chickens. This study describes the development of a rapid dot-enzyme linked immunosorbent assay (dot-ELISA) using recombinant σB protein antigen of 54 kDa (approx). The assay is rapid (4-5 h) and results can be read by the naked eye. Sixteen ARV positive serum samples (group A) produced strong reaction in the dot-ELISA while twenty of the ARV negative serum samples (group B) collected from SPF chickens showed no reaction. Seventy six randomly collected serum samples were tested with a commercial indirect ELISA kit and the in-house developed dot-ELISA. A total of sixty eight serum samples were found to be positive by indirect ELISA and sixty five serum samples were found to be positive by dot-ELISA. Therefore, using the commercial ELISA as the reference test, the dot-ELISA had a diagnostic sensitivity of 83.8% and specificity of 88.6%. This dot-ELISA can be used as a simple, reliable and inexpensive alternative to commercial ELISA kits for serodiagnosis of ARV where the facilities for standard ELISA are not available.