Spread of Integron-Associated VIM-Type Metallo-β-Lactamase Genes among Imipenem-Nonsusceptible Pseudomonas aeruginosa Strains in Greek Hospitals

摘要

Fifty-eight imipenem-nonsusceptible (MIC ≥ 8 μg/ml) Pseudomonas aeruginosa strains isolated during May 2001 in 15 Greek hospitals were studied. Thirty-six isolates derived from nine hospitals carried VIM-type metallo-β-lactamase genes, as found by PCR. In 34 isolates, bla_VIM was associated with class 1 integrons of various sizes. DNA sequencing indicated the presence of bla_VIM-2 gene cassettes in a variety of integron structures. Random amplified polymorphic DNA typing suggested diversity of the bla_VIM-positive strains. Synergy between 2-mercaptoacetic acid and imipenem indicated carbapenemase activity in 26 bla_VIM-positive strains.