Frequency of Class I and II Integrons in Metalobetalactamase Producing Clinical Isolates of Pseudomonas Aeruginosa

Pseudomonas aeruginosa is an opportunistic nosocomial pathogen. Evidence suggests that the incidence of enzyme-producing strains of Pseudomonas aeruginosa Metalo Beta Lactamases (MBL) is a major problem in the treatment of infections caused by this organism. The aim of this study was to investigate the frequency of class I and II integrons among metalobetalactamase producing Pseudomonas aeruginosa isolated from clinical samples from Zanjan hospitals. In this cross-sectional study, 120 Pseudomonas aeruginosa isolates from clinical specimens were collected from Zanjan hospitals in 2012-2013. After verifying isolates by biochemical tests, antibiotic susceptibility testing (Kirby-Baur method) was performed according to CLSI guidelines against 7 antibiotics. The DDST was then carried out for detection of MBLs. Finally, the presence of IntI1, IntI2, blaVIM and blaGIM genes was determined by PCR. In our study, the highest and the lowest resistant patterns were related to Cefotaxime and Amikacin with 43.3% and 21.6%, respectively. Of 120 isolates, the metallo- beta-lactamase was detected in 35 (29%) isolates. According to results, the frequency of intI1, intI2, blaVIM genes in MBL producers were 32(91%), 3(9%), and 6(17%), respectively, but no blaGIM positive isolate was detected. Also all of IntI2 positive isolates carried IntI1 and blaVIM,, simultaneously. The results of this study indicate high frequency of class I integron gene among MBL producing Pseudomonas aeruginosa isolates. Due to the importance of integrons in dissemination of antibiotic resistance genes, detection and prevention of these elements are necessary.