Dissemination of Pseudomonas aeruginosa Producing blaIMP1, blaVIM2, blaSIM1, blaSPM1 in Shiraz, Iran

Metallo-β-lactamase (MBL) producing Pseudomonas aeruginosa is responsible for many important nosocomial outbreaks including pneumonia and septicemia. Various studies have reported the separation of P. aeruginosa producing MBLs enzymes resulted in increases in multiple traditional antibiotics resistance including carbapenems, cephalosporins and penicillins.. In this study, based on the standard phenotypic and genotypic methods, we examined the MBLs possible production of a P. aeruginosa isolate. The main objective was exploring the dissemination of resistant MBL P. aeruginosa in south-west of Iran, Shiraz.. During a six-month period-from October 2011 to March 2012-240 P. aeruginosa isolates, collected from four teaching hospitals in Shiraz located in southwest of Iran, were examined. The isolates were mainly collected from wound, urine, and sputum. Minimum inhibitory concentration (MIC) ≥4 µg/mL to imipenem was determined by micro-dilution broth. Identification of P. aeruginosa with MBL was detected using double disk synergy test (DDST) and polymerase chain reaction (PCR) using specific primers for blaIMP1, blaVIM2, blaSIM1, blaSPM1. All laboratory procedures was according to clinical and laboratory standards institute (CLSI) recommendations.. From 240 P. aeruginosa isolates, 82 (34.16%) isolates were imipenem-resistant (minimum inhibitory concentration (MIC) ≥4 µg/mL). Among these imipenem-resistant isolates, 19 (23.3%) MBL-producing P. aeruginosa isolates were screened using DDST. A specific PCR test confirmed the presence of 18 (21.95%) P. aeruginosa producing blaIMP1 and blaVIM2.. Beside our study, the detection of MBL genes were reported in a few studies conducted in Iran. The spread of detected MBLs producing P. aeruginosa were unprecedented in the region due to the lack of independent related researches or the novel incidence of these genes. This detection must be noted by associated clinical and health care services..