Characterization of VIM, VEB and CTX-M Beta-lactamase Gene in Escherichia coli and Pseudomonas aeruginosa Isolated from Urine Samples of Patients Visiting a Tertiary Hospital in Abakaliki

Abstract

The spread and convergence of multiple beta-lactamase genes across distinct resistant bacterial populations from various hosts and settings demonstrates increased risk of morbidity and mortality in humans. This study was undertaken to characterize blaVIM, blaVEB and blaCTX-M beta-lactamase gene in Escherichia coli and P. aeruginosa isolates from patients visiting a tertiary hospital in Abakaliki. A total of three hundred (300) urine samples were collected from patients and were subjected to bacteriological examination using culture, Gram staining and biochemical technique, for routine microbiological identification and further confirmed using the VITEK-2 Automated System (Biomerieux, France). Antimicrobial susceptibility studies were determined using the Kirby–Bauer disk diffusion method. All isolate were further screen for various beta-lactamase resistant gene by PCR using specific primer. Of the 300 urine samples collected, prevalence rate of 187 (62.3%) and 91 (30.3 %) E. coli and P. aeruginosa were recorded. The isolates exhibited 50.0-100% percentage of resistance to Amoxycillin-Clavulanic acid, Azetronam, Cefoxitin, Ceftriaxone and Piperacillin/tazobactam. The proportion of beta-lactamase gene in E. coli were as follows (VEB 143/76.5 %; CTX-M 175/93.5 %; VIM 77/41.2 %) while beta-lactamase gene in P. aeruginosa were as follows (VEB 91/100 %; CTX-M 63/69.2%; VIM 48/52.7 %). The presence of these gene in our study indicates the possibility of therapeutic failure, serious consequences for infection control and increased risk of morbidity and mortality in patients. Hence, continuous effort in hospital surveillance, infection control, and clinical audits must be conducted to fight against the rapid development and spread of antibiotic-resistant bacteria pathogens. Keywords: Beta-lactamase, Escherichia coli, Pseudomonas aeruginosa, VIM, VEB, CTX-M