Rapid serotyping of enteropathogenic Yersinia enterocolitica strains by co-agglutination

A rapid co-agglutination test using monospecific antisera was developed for the serological typing of enteropathogenic strains of Yersinia enterocolitica. A total of 70 bacterial strains (17 reference strains and 53 clinical isolates) were examined. Absorption of immune sera against serotypes O:3, O:8 and O:9 with their heterologous antigens (S-LPS) was necessary to avoid the appearance of different cross-reactions, as observed by co-agglutination. The proteins present in the S-LPS preparations obtained from each serotype seemed to be responsible for such cross-reactions. Results obtained with a total of 57 clinical isolates belonging to other members of the family Enterobacteriaceae indicate a high specificity of the assay.