Detection of ESBLs and NDM-1 genes among urinary Escherichia coli and Klebsiella pneumoniae from healthy students in Niger Delta University, Amassoma, Bayelsa State, Nigeria

Abstract

Introduction: increasing emergence of multidrug-resistant uropathogens among healthy individuals is a serious public health problem capable of causing difficult-to-treat urinary tract infections (UTIs) with limited treatment options. This study therefore, determined the prevalence of asymptomatic bacteriuria (ASB) and molecular characteristics of antibiotic-resistant Escherichia coli and Klebsiella pneumoniae isolated from healthy students of Niger Delta University, Amassoma, Nigeria. Methods: mid-stream urine samples were collected from 303 healthy students and cultured for significant bacteriuria. Escherichia coli and K. pneumoniae were isolated and identified by conventional methods and Polymerase Chain Reaction (PCR). Antimicrobial susceptibility patterns of the isolates were determined by the disc diffusion technique. The isolates were screened for Extended-Spectrum Beta-Lactamases (ESBLs) production by combined disc method, ESBLs and carbapenemases genes by PCR. Results: the prevalence of ASB was 21.1%, with a significantly higher proportion among the females (P < 0.0001). Escherichia coli and K. pneumoniae isolates were recovered in equal proportion (n=21; 6.9%), with E. coli significantly isolated from the females (P= 0.002). The isolates exhibited 57-95% resistance to cefotaxime, ceftazidime, and co-trimoxazole, and 10-24% resistance to levofloxacin and imipenem. Multidrug resistance (MDR) was found in 9 (42.9%) E. coli and 18 (85.7%) K. pneumoniae isolates; 60% of E. coli and 72.7% of K. pneumoniae were ESBLs producers. blaTEM (50%) and blaCTX-M (30%) were detected in E. coli while blaSHV (83.3%) and blaTEM (55.6%) were detected in K. pneumoniae. One E. coli and two K. pneumoniae isolates harboured NDM-1 gene. Conclusion: the ASB from this study´s healthy individuals was characterized by MDR bacteria that harboured ESBLs and NDM-1 genes. Thus, emphasizing the need for regular surveillance of bacterial resistance and proper hand hygiene to contain the spread of MDR pathogens in the community.