Clones and Their Diagnostic Usefulness

To facilitate the identification and serotyping of Salmonella species, we established a wide variety of murine monoclonal antibodies (MAbs) that were reactive with the lipopolysaccharides (LPSs) of Salmonella serogroups B to E. An effective approach for generating LPS-reactive hybridomas was used; this required immunization of mice with LPS-coated bacteria. To screen for diagnostically useful MAbs, the MAbs were tested by enzyme-linked immunosorbent assay against a set of purified LPSs from smooth and rough Salmonella strains. At least four major groups of antibody specificities were identified: Salmonella (i) BO specific, (ii) CO specific, (iii) DO specific, and (iv) E0 specific. For a more detailed epitope analysis, a panel of eight different serogroup-specific MAbs which were shown to bind the 0-antigenic polysaccharide chains, yielding charac-teristic ladder patterns in Western blots (immunoblots) against the LPS of Salmonella serogroups B to E, were selected. The availability of various chemically defined LPS structures and Salmonella 0-antigen glycoconju-gates permitted the definition of 0-antigenic polysaccharide epitopes recognized by each MAb that serologicall