CHARACTERIZATION OF A LARGE CHROMOSOMAL HIGH-PATHOGENICITY ISLAND IN BIOTYPE 1B YERSINIA-ENTEROCOLITICA

Pathogenic Yersinia spp. can be subdivided into highly pathogenic (hig h-pathogenicity) and Low-pathogenicity strains. Several genes specific for the high-pathogenicity strains are clustered on a chromosomal fra gment designated a ''high-pathogenicity island'' (HPI). In the present work, the HPI of biotype 1B strain Ye 8081 of T. enterocolitica was c haracterized. We demonstrate important differences from the HPI of Y. pestis. The HPI of Y. enterocolitica is smaller (45 kb) and is not fla nked by insertion sequences. A copy of the gene coding for the tRNA-As n is present at one extremity of the HPI and may, as in uropathogenic Escherichia coli, participate in the excision of the island. In additi on to the genes encoding the yersiniabactin-pesticin receptor and the high-molecular-weight protein 2, four repeated sequences are present o n the HPI of Y. enterocolitica. At least two of them are insertion ele ments: previously described IS1328 and newly characterized IS1400. Com parison of the HPI of strain Ye 8081 with that of other Y. enterocolit ica strains of biotype 1B indicates that most of the island is conserv ed, apart from 15 kb at the left-hand end which is variable, especiall y in the region where three repeated sequences are clustered.