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 pat hogenicity island termed HPI (high-pathogenicity island) and R-HPI (the rig ht-hand part of the HPI with truncation in its left-hand part) on the chrom osome. Analysis of the distribution of these virulence factors allowed for differentiation of species Y. pseudotuberculosis into six subgroups, thus r eflecting 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+ Euro pean 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-ferme nting 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 belong ing to nonmelibiose-fermenting serotype 03 and the YPMs- HPI- pathogenic ty pe 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.