Plasmid associated antibody production against Yersinia enterocolitica in man.

The presence of plasmids was studied in 46 Yersinia enterocolitica strains isolated from human fecal specimens. In the 36 cases where specific antibodies were detected, 33 of the isolated bacteria were harbouring a 45-48 Mdalton plasmid responsible for autoagglutination and Ca2+ dependent growth at 37 degrees C. Symptoms compatible with yersiniosis were present in all patients where information was available. In the 10 cases with clinical symptoms but without specific antibodies only 2 of the isolated yersinia strains contained plasmids which were of another size. These results indicate an association between the presence of the 45-48 Mdalton plasmid in Y. enterocolitica strains and the pathogenicity of the strains to human hosts.