Detection of metallo-b-lactamase-encoding genes among clinical isolates of Pseudomonas aeruginosa in northwest of Iran

The prevalence of metallo-b-lactamase (MBL) production among 104 clinical isolates of Pseudomonas aeruginosa from northwest of Iran was investigated by phenotypic and polymerase chain reaction (PCR) methods. Thirty-nine (37.50%) of isolates were MBL positive by double-disk synergy test. Results of PCR revealed that 18 (17.31%) and 6 (5.77%) imipenem nonsusceptible isolates of P. aeruginosa carried bla VIM and bla IMP genes respectively, while 92.4% (62/67) of isolates contained class 1 integron gene. This is the first report of MBL-producing P. aeruginosa from northwest of Iran.