Molecular detection of selected extended-spectrum beta-lactamase resistant genes in escherichia coli isolated from cancer patients with urinary tract infections in Abuja

Abstract

Urinary tract infections (UTIs) are among the most common infections in cancer patients and are frequently complicated by antimicrobial resistance, particularly due to extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli. This study aimed to determine the prevalence, antimicrobial resistance patterns, and selected molecular characteristics of ESBL-producing E. coli isolated from cancer patients with UTIs at the National Hospital Abuja, Nigeria. A total of 162 urine samples were collected and analyzed using standard microbiological methods. Isolates were identified as E. coli, followed by antibiotic susceptibility testing in accordance with Clinical and Laboratory Standards Institute (CLSI) guidelines. Phenotypic detection of ESBL production was performed using antibiotic susceptibility testing and the VITEK 2 Compact system, while molecular detection of selected ESBL genes was carried out using polymerase chain reaction (PCR). Out of 162 samples, 18 (11.2%) E. coli isolates were recovered. A higher occurrence was observed in males (15.0%) compared to females (9.8%), and among patients aged ≥70 years (21.4%). The isolates exhibited high resistance to ampicillin (100%), cefuroxime (83.3%), trimethoprim-sulfamethoxazole (77.7%), and ceftriaxone (66.6%), while showing complete susceptibility to amikacin and meropenem (100%). Multiple antibiotic resistance (MAR) indices ranged from 0.5 to 0.9, with 0.8 being the most frequent. Of the 18 isolates, 8 (44.4%) were confirmed as ESBL producers. Among these ESBL-producing isolates, blaSHV, blaCTX-M-4, and blaCTX-M genes were detected in 62.5%, 50.0%, and 37.5% of isolates, respectively, while blaTEM was not detected. In conclusion, there is a notable presence of multidrug-resistant and ESBL-producing E. coli among cancer patients with UTIs in the study area, posing a significant therapeutic challenge. These findings highlight the need for routine surveillance, antimicrobial stewardship, and the integration of molecular diagnostics in clinical settings, and clinicians are encouraged to adopt evidence-based antibiotic therapy and strengthen infection control practices to limit the spread of resistant strains.