Development of an immunoglobulin m (IgM) capture enzyme-linked immunosorbent assay for detection of equine and swine IgM antibodies to vesicular stomatitis virus

An immunoglobulin M (IgM) capture enzyme-linked immunosorbent assay (MC-ELI SA) was developed for the detection of primary infection of vesicular stoma titis virus (VSV) in equine and swine sera. The test was based on the use o f biotinylated sheep antibodies against equine or swine IgM molecules bound to a streptavidin-coated ELISA plate. The captured IgM antibodies were det ected by application of antigens prepared from the New Jersey and the India na VSV serotypes (VSV-NJ and VSV-IN, respectively) and mouse polyclonal ant ibodies against VSV-NJ and VSV-IN, The MC-ELISA was compared to a competiti ve ELISA (C-ELISA) and the standard microtiter serum neutralization (MTSN) assay by testing serum samples from horses and pigs experimentally infected with VSV-NJ or VSV-IN, The MC-ELISA detected specific homologous IgM antib odies from equine and swine sera as early as 5 and 4 days postinfection (DP I), respectively, and as late as 35 DPI. The MTSN test also detected antibo dies as early as 5 DPI and as late as 160 DPI. In a similar fashion, the C- ELISA detected antibodies from 6 to 7 DPI and as late as 160 DPI. These res ults demonstrated that the MC-ELISA is a useful test for serodiagnosis of p rimary VSV infection in horses and pigs.