Predictors of Multidrug-Resistant Urinary Tract Infections in Women: A Large Retrospective Cohort Study in a Romanian University Hospital

Urinary tract infections (UTIs) represent a major cause of morbidity among adult women, with a disproportionate burden among postmenopausal patients. Limited data exist from Eastern Europe regarding pathogen distribution, antimicrobial resistance, and treatment patterns in hospitalized women. We conducted a retrospective cohort study of 948 adult female patients hospitalized with symptomatic UTIs between January 2021 and December 2023 in a Romanian multidisciplinary hospital. Demographic, clinical, and microbiological parameters were analyzed. Pathogen identification was performed by MALDI-TOF MS, and antimicrobial susceptibility testing followed EUCAST 2024 standards. Empiric treatment strategies and subsequent therapy modifications were assessed. Postmenopausal women accounted for 78.4% of cases and exhibited higher rates of recurrent UTIs, frailty, diabetes, urinary catheterization, and prior antibiotic exposure. Escherichia coli remained the predominant pathogen (52.6%), followed by Klebsiella spp. (18.4%) and Enterococcus spp. (12.1%). ESBL-producing organisms were found in 21.4% of E. coli and 38.7% of Klebsiella isolates. Pathogen distribution differed by age: younger women had a higher proportion of E. coli, whereas postmenopausal women showed a relative increase in opportunistic/healthcare-associated pathogens, particularly Klebsiella spp. and Enterococcus spp., consistent with higher catheter exposure and comorbidity burden. Carbapenem resistance was rare but present in a small subset of Klebsiella isolates with phenotypes compatible with OXA-48-like carbapenemase production. Empiric therapy most frequently included ceftriaxone or fluoroquinolones, but 27.8% of regimens required adjustment after susceptibility results. Independent predictors of prolonged hospitalization included age > 65 years, recurrent UTI, MDR infection, urinary catheterization, and delayed targeted therapy. UTIs among hospitalized adult women—especially postmenopausal patients—are strongly influenced by comorbidity burden and antimicrobial resistance. Local resistance patterns highlight the need for evidence-based empiric treatment and rapid therapy optimization. Strengthening stewardship and preventive interventions in elderly women is essential.