Gains and Losses in Yersinia enterocolitica subsp. palearctica Genomes

Enteropathogenic Yersinia enterocolitica has been assembled into two subspecies, Y. enterocolitica subsp. enterocolitica for biotypes (BT) 1B and Y. enterocolitica subsp. palearctica for BT 1A and BT 2–4. Y. enterocolitica subsp. palearctica BT 2–4 are low pathogenic while BT 1A is considered “apathogenic” or “nonpathogenic.” The deciphered genomes of BT 2–4 strains confirmed the absence of several high-pathogenicity determinants of the 1B group but contain an alternative patchwork of virulence and fitness-associated factors that might be involved in pathoadaptation and successful worldwide dissemination. Although 1A strains lack most of the classical virulence determinants they possess other potential virulence-associated markers that might be responsible for their pathogenicity. In total, the presence of known and putative virulence-associated features in Y. enterocolitica subsp. palearctica compels to reconsider properly the pathogenic potential of this group of emerging pathogens.