Characterization and pathogenicity of Yersinia pseudotuberculosis isolated from swine and other animals

Yersinia pseudotuberculosis serogroup III is most frequently detected in healthy pigs. Y. pseudotuberculosis strains were divided into two biogroups on the basis of their fermentation of melibiose. Melibiose-fermenting strains were distributed in all the hosts and serogroups examined. Melibiose-nonfermenting strains were limited to serogroup III isolated from healthy pigs. Autoagglutination and calcium dependency were not related to fermentation of melibiose. Melibiose-fermenting strains seem to be virulent for mice, but melibiose-nonfermenting strains showed no virulence for mice.