Carbapenem resistance due to metallo beta lactamases (MBLs) has grown as a health care problem in recent decades. The present study has investigated the antibiotic susceptibility patterns and screening of MBLs producing P. aeruginosa isolates at two university hospitals in northwest of Iran. Furthermore, serotyping, PFGE and MLST were used for studying the clonal relationship among the isolates. In brief our findings showed that blaVIM and blaIMP types MBLs are common in our area. All MBLs producing isolates were non-susceptible to imipenem, majority of them belonged to MDR phenotype and O10 or O11 serotypes. Also, a multi-drug resistant clone of P. aeruginosa was identified in a burn unit in Orumieh- Iran, which majority of them belonged to O10 serotype, and most of them were sequence type, ST773. In conclusion, since MBLs producing isolates are resistant to most antibacterial agents, early detection of such isolates is crucial to choose appropriate therapeutic regimens and prevent dissemination of this type of resistance. Finally our findings emphasize the importance of continually following the epidemiological relatedness of MDR P. aeruginosa spreading in ICUs and burn units.
