Metallo-beta-lactamase-producing imipenem-resistant Pseudomonas aeruginosa clinical isolates in a university teaching hospital in Malaysia: detection of IMP-7 and first identification of IMP-4, VIM-2, and VIM-11.

Ninety (n = 90) imipenem-resistant Pseudomonas aeruginosa (IRPA) clinical isolates collected randomly during 2005 to 2008 from University Malaya Medical Center were assessed for the presence of different variants of metallo-beta-lactamase (MBL) genes. Polymerase chain reaction (PCR) assay detected 32 (n = 32) MBL gene PCR-positive isolates with the presence of bla(IMP) gene in 14 (n = 14) and bla(VIM) in 18 (n = 18) isolates. Four allelic variants, bla(IMP-7) (12 isolates), bla(IMP-4) (2 isolates), bla(VIM-2) (17 isolates), and bla(VIM-11) (1 isolate), of MBL genes were identified. This study is the first report of detection of bla(IMP-4), bla(VIM-2), and bla(VIM-11) MBL genes from IRPA clinical isolates in Malaysia.