Plasmid DNA relatedness among different serogroups of Yersinia pseudotuberculosis.

Thirteen different serogroup strains of Yersinia pseudotuberculosis and two strains of Yersinia enterocolitica O:3 were examined for the presence of plasmids and plasmid-mediated properties, calcium growth dependency, and autoagglutination. Two Y. enterocolitica strains and eight serogroup (IA, IIA, IIC, III, IVA, VB, VI, and VIII) strains, except for five serogroups (IB, IIB, IVB, VA, and VII), of Y. pseudotuberculosis harbored plasmids ranging in molecular size from 27 to 115 kilobases. Filter hybridization of restriction endonuclease-digested plasmid DNA from different serogroup strains indicated that all plasmid DNAs conferring calcium growth dependency and autoagglutination shared a high degree of DNA sequence homology, regardless of the different serogroups of Y. pseudotuberculosis and Y. enterocolitica.