Spread of bla(VIM-1)-producing E. coli in a university hospital in Greece. Genetic analysis of the integron carrying the bla(VIM-1) metallo-beta-lactamase gene.

Bla(VIM-1) gene was detected in four Escherichia coli clinical isolates with both reduced susceptibility to carbapenems and an ESBL phenotype. The VIM-1 determinant was located within the variable region of a Class I integron along with a 6'-N-aminoglycoside acetyltransferase gene (aac(6')-Ib) and it could be transferred by conjugation. In all four clinical isolates the VIM-1 gene cassette presented a characteristic duplication of the 3' end coding 153 nucleotides followed by the first 14 nucleotides of the 59 base element (59be) that however did not seem to affect either the integrity of the coding sequence or the 59be of the gene cassette. These clinical isolates not only harbored the same Class I integron, but they also shared the same discrete ribotype-pattern, indicative for their clonal origin. Spread of carbapenem resistance genes among Enterobacteriaceae in hospital is a matter of great concern.