Production and characterization of monoclonal antibodies specific for pathogenic serogroups O:3, O:8, and O:9 of yersinia enterocolitica

Summary A panel of 7 murine hybridoma derived monoclonal antibodies (MAbs) to Yersinia enterocolitica were produced and characterized by indirect fluorescence assay (IFA) and agglutination reactions. One MAb designated 2D8 (IgG 3) showed specific reactivity both in the IFA and agglutination assays with 70 of the 70 strains belonging to serogroup O:3 of Y. enterocolitica . Three MAbs, 8E9 (IgG 3b), 10G11 (IgG3) and 11G2 (IgG 3), gave unequivocal positive reactions in the IFA and agglutination tests with all the strains representing serogroup O:9 (56/56), but not with serogroup O:3 or O:8 strains. Another MAb coded 1G2 (IgG 1) reacted specially in the IFA test (but not in the agglutination test) with all the strains representing serogroup O:3 (70/70) and O:9 (56/56) indicating that this antibody recognizes an immunodeterminant shared by serogroups O:3 and O:9. Finally, 2 MAbs 4C2 (IgM) and 6G5 (IgM), showed reactivity both in IFA and agglutination assays with “esculin negative” biogroups 1 (pathogenic American strains) strains of serogroup O:8 (12/12), whereas the strains assigned to “esculin positive” biogroup 1 (nonpathogenic) failed to react (6/6). However, 4C2 and 6G5 exhibited narrow cross reactivity with type strains assigned to serogroups O:18, O:20, and O:22. The results of absorption tests and the clear out cell wall immunofluorescence imply that the antigenic molecule(s) recognized by these MAbs are exposed on the bacterial cell surfaces. Some of the MAbs described in this report are useful reagents for precise serotyping of clinical isolates of Y. enterocolitica by simple and rapid slide agglutination assay. They may also allow the development of specific and sensitive tests for probing the presence of pathogenic Y. enterocolitica organism in clinical and food materials.