Antimicrobial resistance and associated risk factors in urinary tract infections diagnosed in the emergency department: a retrospective observational study

BACKGROUND: Urinary tract infections (UTIs) are among the most common causes of emergency department admissions and represent a major source of antimicrobial use worldwide. The aim of this study was to determine antimicrobial resistance patterns and associated risk factors among patients diagnosed with UTIs in the emergency department. METHODS: This retrospective observational study included 1,042 adult patients diagnosed with UTIs in the ED of a tertiary referral hospital. Demographic characteristics, clinical findings, urine culture results, antimicrobial susceptibility profiles, and resistance-associated risk factors were analyzed. RESULTS: Gram-negative bacteria accounted for 74.6% of isolates, with Escherichia coli (43.1%) and Klebsiella spp. (22.3%) being the predominant pathogens. High resistance rates were observed for ciprofloxacin (47.6%), ceftriaxone (47.0%), and trimethoprim-sulfamethoxazole (41.3%). ESBL production and carbapenem resistance were detected in 16.9% and 17.9% of Gram-negative isolates, respectively. Recent antibiotic use, indwelling urinary catheterization, and malignancy were identified as independent risk factors for ESBL positivity. Male sex, malignancy, and indwelling urinary catheterization were independently associated with carbapenem resistance. Among Enterococcus spp. isolates, vancomycin resistance remained very low (0.9%), whereas ampicillin resistance was detected in 23.7% of isolates. CONCLUSIONS: These findings underscore the critical importance of incorporating local resistance surveillance into empirical treatment decisions, adopting individualized therapeutic approaches, and strengthening antimicrobial stewardship programs in emergency departments.