Monoclonal antibody-based enzyme-linked immunosorbent assays for identification and serotyping of Vibrio cholerae O1.

Monoclonal antibodies directed against O-specific antigens of Vibrio cholerae O1 lipopolysaccharide were used in two different enzyme-linked immunosorbent assays (ELISAs), designed for identification and serotyping of V. cholerae O1. In the sandwich ELISA, a monoclonal antibody against the group-specific antigen was used as capture antibody, whereas peroxidase-conjugated monoclonal antibodies directed against group- and type-specific antigens were used as the second antibodies. Monoclonal antibodies were also used in ELISA inhibition tests with whole bacteria as inhibitors in microtiter trays coated with V. cholerae O1 lipopolysaccharide. In addition, the monoclonal antibodies were shown to be useful in slide agglutination tests. The enzyme immunoassays were equally sensitive, showing positive reactions with all V. cholerae O1 strains tested, whereas all V. cholerae non-O1 as well as strains of Escherichia coli, Shigella sonnei, Salmonella spp., Citrobacter freundii, and Brucella abortus were negative. The microtiter application makes the immunoassays suitable with low consumption of reagents for screening of samples from suspected cases as well as from the environment.