Prevenance of the mexA and gyrA genes in Antibiotic-Resistant Pseudomonas aeruginosa isolated from urinary tract infections

Abstract

Pseudomonas aeruginosa is an opportunistic pathogen of importance in the context of urinary tract infections, at least in part, due to the ability of this organism to develop resistance to the frontline antimicrobial agents. The objective of the study was to identify the antimicrobial resistance pattern and frequency of the mexA and gyrA genes among P. aeruginosa strains isolated from urinary tract infections. A cross-sectional study was carried out at Hilla Teaching Hospital Were located in Babylon Province, south of Iraq since July 2024 until January 2025. The study included 82 P. aeruginosa isolates obtained from urinary culture of patients with clinically suspected urinary tract infections. The antimicrobial susceptibility testing was carried out using the Kirby–Bauer disk diffusion method according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Genomic DNA involved detection of the mexA and gyrA genes on the isolates.The resistance rates were highest for ciprofloxacin (75.6%), ceftazidime and levofloxacin (70.7% each), cefepime (67.1%), piperacillin-tazobactam (62.2%), gentamicin (58.5%), imipenem (53.7%), and meropenem (50.0%). Molecular analysis revealed that the mexA gene was present in 75 (91.5%) isolates, and gyrA was detected in 78 (95.1%) isolates. Most P. aeruginosa isolates from urinary tract infections showed high resistance rates to fluoroquinolones and cephalosporins, two classes of antipseudomonal agents used frequently. The mexA prevalence indicates a potential role for efflux-mediated mechanisms in the resistance profile.