Development and application of G1-ELISA for detection of antibodies against bovine ephemeral fever virus.

The gene encoding antigenic site G(1) of bovine ephemeral fever virus (BEFV) was highly expressed in the host cell Escherichia coli. An indirect G(1)-ELISA with the recombinant protein as the coating antigen was established to detect antibodies against BEFV. The result revealed that the optimal concentration of the coated antigen was 0.5 microg/well and the dilution of serum was 1:20. It was optimal that sera with P/N >or= 2.2 were considered positive, P/N <or=2.0 negative, and between 2.0 and 2.2 ambiguous. The G(1)-ELISA method gave a sensitivity of 97.6% and a specificity of 98.6% by testing 590 field serum samples. These results suggest that the G(1)-ELISA may be a good alternative tool for seroepidemiological surveys.