Geographical heterogeneity between Far Eastern and Western countries in prevalence of the virulence plasmid, the superantigen Yersinia pseudotuberculosis-derived mitogen, and the high-pathogenicity island among Yersinia pseudotuberculosis strains

Yersinia pseudotuberculosis produces novel superantigenic toxins designated YPMa (Y. pseudotuberculosis-derived mitogen), YPMb, and YPMc and has a pathogenicity island termed HPI (high-pathogenicity island) and R-HPI (the right-hand part of the HPI with truncation in its left-hand part) on the chromosome. Analysis of the distribution of these virulence factors allowed for differentiation of species Y. pseudotuberculosis into six subgroups, thus reflecting the geographical spread of two main clones: the YPMa(+) HPI- Far Eastern systemic pathogenic type belonging to serotypes 01b, -2a, -2b, -2c, -3, 4a, 4b, -5a, -5b, -6, -10, and UT (untypeable) and the YPMs- HPI+ European gastroenteric pathogenic type belonging to serotypes 01a and -1b. The YPMa(+) HPI+ pathogenic type belonging to serotypes 01b, -3, -5a, -5b, and UT and the YPMb(+) HPI- nonpathogenic type belonging to non-melibiose-fermenting serotypes 01b, -5a, -5b, -6, -7, -9, -10, -11, and -12,were prevalent in the Far East. The YPMc(+) R-HPI+ European low-pathogenicity type belonging to nonmelibiose-fermenting serotype 03 and the YPMs- HPI- pathogenic type belonging to 15 serotypes were found to be prevalent all over the world. This new information is useful for a better understanding of the evolution and spread of Y. pseudotuberculosis.