Application of Indirect ELISA for Detection of Bovine Antibodies against Vesicular Stomatitis Viruses

Abstract

Two indirect enzyme-linked immunosorbent assays (I-ELISAs) are described for the detection of bovine serum antibody to the New Jersey (NJ) and Indiana (IN) vesicular stomatitis viruses (VSV). Serum samples at a dilution of 1:200 were incubated with binary ethylenimine-inactivated VSV-NJ and VSV-IN type-specific antigens preadsorbed to microtiter plates. Bound antibodies were detected by a murine monoclonal antibody to bovine IgG 1 conjugated with horseradish peroxidase. The performance of each I-ELISA in detecting homotypic and heterotypic antibodies to VSV-NJ and VSV-IN in sequential serum samples from calves experimentally infected with VSV-NJ or VSV-IN was evaluated. The I-ELISAs detected serotype-specific antibodies to either VSV-NJ or VSV-IN in calves infected with the homologous serotype. Homotypic but not heterotypic anti-VSV-NJ antibodies were first demonstrable by the VSV-NJ I-ELISA during the second week postinfection and remained at an elevated level for a period of 11 weeks, with a gradual decrease thereafter. Similar homotypic antibody profiles measured by the VSV-IN I-ELISA in calves inoculated with VSV-IN were observed. The performances of the I-ELISAs were compared using 1,495 microtiter serum neutralization (MTSN) test-negative bovine field sera collected from cattle in Canada (VS free) and 429 samples collected from cattle in the USA and Mexico (VS-epidemic and VS-endemic areas). The diagnostic specificities of the VSV-NJ and VSV-IN I-ELISAs for the Canadian samples relative to the MTSN test results were in the range of 99.8% and 99.7%, respectively. The levels of agreement between the VSV-NJ and VSV-IN I-ELISAs and the MTSN test for the 429 bovine field samples from VS-epidemic and VS-endemic areas were 97.7% and 98.8%, respectively. Relative to MTSN, the sensitivity and specificity of the 429 field sera for the VSV-NJ I-ELISA were 95.4% and 99.6%, respectively, and for the VSV-IN assay were 75.0% and 99.2%, respectively. The results suggest that in addition to the many technical advantages over the MTSN test these I-ELISAs have potential application as rapid and inexpensive tests for the serodiagnosis of VSV infection in cattle.