Different types of monoclonal antibodies to Ogawa-specific and group-specific antigens of Vibrio cholerae O1

Nine monoclonal antibodies to Ogawa-specific antigenic determinants of Vibrio cholerae O1 and seven monoclonal antibodies to the Ogawa-Inaba common antigenic determinants were obtained. Specificities and reactivities were examined by slide or microdilution agglutination methods, along with enzyme-linked immunosorbent assays and immunoblotting analysis. In both the Ogawa-specific and Ogawa-Inaba common groups, it was revealed that there were two types of antibodies. One type showed strong agglutination with both live cells and heat-killed (100 degrees C for 30 min) cells in the microdilution agglutination test and in the slide agglutination test (type 1), while the other showed rather weak agglutination with heat-killed cells, especially in the slide agglutination test (type 2). Electronic measurement of agglutinates from these antibodies revealed that the size of aggregates varied. In the case of the type 2 antibodies, the size of aggregates obtained with heat-killed cells was smaller than those obtained with Formalin-killed cells. Results of enzyme-linked immunosorbent assays and immunoblotting analysis showed that all 16 antibodies were to the lipopolysaccharide of V. cholerae O1.