[The molecular basis of the virulence of Yersinia].

Pathogenic bacteria of the genus Yersinia (Y. enterocolitica, Y. pseudotuberculosis and Y. pestis) are pathogens of the invasive type. Although they provoke diseases as different as plague and enterocolitis, the molecular bases of their virulence appear to be surprisingly similar: a 70 kb plasmid confers a degree of resistance to the primary immune response and the presence or absence of chromosome encoded functions modulates virulence. The knowledge of the virulence functions that now emerges suggests the conversion of Y. enterocolitica as a life carrier.