Plasmids in Yersinia enterocolitica serotypes O:3 and O:9: correlation with epithelial cell adherence in vitro

Abstract

Human isolates of Y. enterocolitica serotypes O:3 (biotype 4) and O:9 (biotype 3) harbored plasmids sized .apprx. 47 and 44 Mdaltons, respectively. No such plasmids were found in apathogenic strains of Y. enterocolitica belonging to biotype 1. There was a positive correlation among the presence of plasmid, autoagglutination and adherence to and toxicity for HEp-2 cell [human epidermoid] cultures; all of these properties were lost by culturing at 37.degree. C in the absence of Ca. Strains of Y. enterocolitica O:3 and O:9 cured of the plasmids showed increased invasiveness in the HEp-2 cell culture model, but no invasiveness in guinea pig eye. The plasmids of Y. enterocolitica may primarily determine epithelial cell adherence, but may also be associated with other pathogenic properties.