Development of monoclonal antibody-linked ELISA for sero-diagnosis of vesicular stomatitis virus (VSV-IN) using baculovirus expressed glycoprotein.

The gene encoding the envelope glycoprotein (GP) of vesicular stomatitis virus serotype, Indiana (VSV-IN), was expressed under the polyhedron promoter of baculovirus. The recombinant GP was applied as a diagnostic antigen for the detection of cattle and horse antibodies to VSV. In addition, the neutralizing monoclonal antibody (Mab) to GP of VSV-IN was used as trapping antibody in a Mab-linked indirect ELISA (MLI-ELISA) or detecting antibody in a Mab-linked competitive ELISA (MLC-ELISA). The diagnostic efficiencies of MLI-ELISA and MLC-ELISA were evaluated with currently available C-ELISA from OIE reference laboratory for vesicular stomatitis as a gold standard by using VSV-positive equine sera and negative bovine sera vaccinated against foot-and-mouth disease (FMD) in the field. When naturally infected equine sera and FMDV vaccinated bovine sera were tested, MLI-ELISA and MLC-ELISA showed relative sensitivities of 80% and 95% with relative specificity of 97% and 99%, respectively. However, both ELISAs cross-reacted with equine sera against New Jersey (VSV-NJ) serotype. The comparison of the two ELISAs revealed that MLC-ELISA was relatively more sensitive and specific than MLI-ELISA, indicating that MLC-ELISA can be applied to sero-diagnosis for VSV-IN infection.