Comprehensive Analysis of Urinary Tract Infections: Investigating Risk Factors, Antimicrobial Resistance Profiles, and Beta-lactamase Genotyping for Effective Management Strategies

Background: Urinary tract infections (UTIs) are a prevalent global health issue, primarily caused by bacteria such as Escherichia coli. Understanding the risk factors associated with UTIs and the antimicrobial resistance patterns of uropathogens is crucial for effective management strategies. Objectives: This study aimed to assess risk factors associated with UTIs, determine antimicrobial susceptibility patterns, and identify extended-spectrum beta-lactamase (ESBL) and carbapenemase genes in bacterial isolates. Methods: This cross-sectional study included 274 patients with positive urine cultures at Ganjavian Hospital, Dezful (April 2021 - March 2022). Demographic and clinical data were collected. Urine samples were cultured, and bacterial isolates were identified using standard microbiological techniques. Antimicrobial susceptibility was tested by the disk diffusion method per CLSI guidelines. The ESBL and carbapenemase production were detected phenotypically using combined disk and modified carbapenem inactivation method (mCIM)/EDTA-modified carbapenem inactivation method (eCIM) tests. Molecular detection of resistance genes (blaCTX-M, blaSHV, blaTEM, blaNDM, blaKPC, blaAmpC) was performed using polymerase chain reaction (PCR). Data analysis was conducted with SPSS and WHONET software. Results: Escherichia coli (48.9%) and Klebsiella spp. (23.7%) were the predominant isolates. The ESBL production was observed in 36.3% of isolates, mainly linked to catheterization and nosocomial infections. Carbapenemase production was identified in 12.5% of Enterobacterales and Pseudomonas aeruginosa. The study identified blaCTX-M as the prevalent ESBL gene and blaNDM among carbapenemase producers. Significant associations were found between resistance patterns and factors such as recent antibiotic use, hospital stay duration, and male gender. Escherichia coli showed high resistance to nalidixic acid, TMP-SMX, and ceftriaxone but retained sensitivity to nitrofurantoin and colistin. Conclusions: This study underscores the imperative for a comprehensive approach to UTI management, integrating antimicrobial stewardship, infection control measures, and continued surveillance to mitigate the impact of antimicrobial resistance on patient outcomes and public health.