Characterization and utilization of monoclonal antibodies reactive to Yersinia pseudotuberculosis

The 3 murine monoclonal antibodies, Yps1, Yps2 and Yps3 reactive to Y. pseudotuberculosis can be stabilized and all were found to be of IgG type. Monoclonal antibody, Yps1, recognized a glycoprotein antigen of the organism with reactivity at the 55-75 kDa region, while Yps2 and Yps3 recognized protein antigens of Y. pseudotuberculosis 65 kDa and 26-28 kDa molecular weight regions, respectively. The specificity of monoclonal antibodies was tested using dot ELISA and Western blotting with whole cell organisms or whole cell sonicated soluble antigens of different Yersinia species, Salmonella typhi, Klebsiella pnemoniae, Streptococcus abortus-equi and Escherichia coli. Monoclonal antibody, Yps1 exhibited cross-reactivity with soluble antigens and whole cell preparations of Y. pestis. Yps2 cross-reacted to soluble antigens of all the tested bacteria. Reactivity of monoclonal antibody, Yps3 was restricted to Y. pseudotuberculosis and Y. pestis with soluble antigen preparations. No reaction was observed with Yps2 and Yps3 to whole cell organism preparations from tested bacteria including Y. pseudotuberculosis. The co-agglutination reagent prepared by sensitizing staphylococcal cells with Yps1 monoclonal antibody produced a positive agglutination with all the 4 Y. pseudotuberculosis isolates and the 3 Y. pestis strains tested. Sandwich dot ELISA using monospecific antisera as a capture antibody and a monoclonal antibody, and Yps3 as a revealing antibody had a high level of specificity in detecting Y. pseudotuberculosis antigens.