Investigation of blaIMP-1, blaVIM-1, blaOXA-48 and blaNDM-1 carbapenemase encoding genes among MBL-producing Pseudomonas aeruginosa

Abstract

Pseudomonas aeruginosa (P. aeruginosa) places among major opportunistic nosocomial pathogen which has developed extensive drug resistance. Due to uncontrolled consumption of antibiotics, multidrug-resistant (MDR) P. aeruginosa species are increasingly isolated from various settings of hospitals globally. This research aimed to determine the genes reproducing blaOXA-48, blaIMP-1, blaVIM-1 and blaNDM-1 metallo beta lactamase (MBL) genes from MDR P. aeruginosa isolates. Herein, the isolates of 200 P. aeruginosa have been obtained from microbiology laboratory of burn ward. The antibiotic susceptibility profile was using Disc Diffusion Method (DDM and in compliance with CLSI (Clinical and Laboratory Standards Institute) advice. Study of MBL-bearing strains and the existence of encoding genes was specified by means of polymerase chain reaction. In addition, pulsed field gel electrophoresis (PFGE) is performed for typing. In this study, 124 (62%) were extended spectrum β-lactamase producer and 51 (25.5%) were MBL producers. Moreover, 148 (74%) isolates were MDR-P. aeruginosa. Additionally, 42 (21%), 21 (10%), 10 (5%) and 2 (1%) isolates carried the blaIMP-1, blaOXA-48, blaVIM-1 and blaNDM-1 genes, respectively. The PFGE showed no genetic relationships among isolates. The study observed high rate of MDR P. aeruginosa in hospital settings, though not being outbreak, which nearly half of them carried carbapenemase enzymes. Therefore, the proper control of related infections and appropriate prescription and consumption of antibiotics is essential.