Abstract

MBL (Metallo-beta-lactamases) producing Pseudomonas aeruginosa isolates are the most common opportunistic organisms with multidrug resistance (MDR) in hospital infections. The aim of this study was to determine the frequency of MBL producing isolates, antibiotic resistance pattern, and detection of the related genes using PCR technique. In this descriptive cross-sectional study, 150 clinical samples were collected from different wards (Internal, Surgical, and ICU) of Baqiyatallah Hospital during 2017, and isolates were identified by biochemical, and microbiology tests. Antibiotic susceptibility testing was performed using the Kirby-Bauer disk diffusion method. To detect beta-lactamases, Double Disc Synergy Test (DDST) and Metallo-beta-lactamase detection test were used. And genes associated with beta-lactamases and Metallo-beta-lactamases were detected by PCR technique. Data were analyzed by SPSS software through Chi-square statistical test. Of 150 clinical specimens 75 P. aeruginosa isolates recovered, and 68.6 of those were MBLs producers. The highest resistance belonged to Ciprofloxacin (94.66), followed by Amikacin (93.44), and no resistance was observed to Polymyxin B. The highest prevalence of genes in P. aeruginosa isolates was reported for vim (100) and aac6 (95.71). Results of this study showed that the prevalence of MBLs in patients hospitalized in Baqiyatallah Hospital, Tehran (Iran) was high, which causes resistance to a wide range of antibiotics. Also, due to the lack of resistance to Polymyxin B, this antibiotic is a suitable drug choice for treatment of life threating infections produced by P. aeruginosa in the studied wards, although the toxic effect of it should be considered.