Evolution of an integron carrying bla_VIM-2 in Eastern Europe: Report from the SENTRY Antimicrobial Surveillance Program

As part of the SENTRY Antimicrobial Surveillance Program, an imipenem-resistant Pseudomonas aeruginosa strain (81-11963A) was isolated from the blood culture of a female neonate institutionalized at the local children's hospital in Warsaw, Poland. Cloning of an imipenem resistance determinant revealed it to be a VIM-2 metallo-beta-lactamase, but sequence analysis of DNA adjacent to blaVIM-2 revealed it to have a unique gene context. Downstream of the blaVIM-2 gene resides an aacA4 gene encoding the AAC(6')-Ib aminoglycoside acetyltransferase. The integron containing blaVIM-2 shows high similarity to that reported from In58 in France but was novel in that it possessed a gene cassette with a 59 truncated base element only 19 base pairs (bp) long, consisting of a conserved core site and an inverse core site separated by only 5 bp. This appears to be the first report of a metallo-beta-lactamase gene arising from a pathogenic strain in Eastern Europe.