[Uncomplicated urinary tract infection: microbiology and antimicrobial resistance]

Uncomplicated urinary tract (UTI) infections are a frequent cause of medical consultation in healthy adult women, with most cases treated empirically. Antimicrobial susceptibility has been shown to change over time. Our objectives were to analyze the microbiology and antimicrobial resistance patterns in positive urine cultures obtained from women with UTIs at two hospitals in Córdoba, Argentina, and to assess susceptibility changes by comparing our findings with previous local studies.

A prospective analytical study was conducted in two tertiary care centers, Hospital Privado Universitario de Córdoba and Hospital Raúl ángel Ferreyra, from September 2022 to March 2023. Women aged ≥18 years with UTI infections and no risk factors for complicated infections were included. Cases of asymptomatic bacteriuria were excluded.

A total of 1640 urine cultures were analyzed, of which 271 met the criteria for uncomplicated UTIs, with the majority corresponding to cystitis (n=213, 78.6%). Escherichia coli predominated (n=244, 90%), showing high sensitivity rates to nitrofurantoin and fosfomycin. Klebsiella pneumoniae was the second most common isolate. Twenty-three multidrug-resistant organisms were detected, with no significant difference between women over and under 50 years of age.

Escherichia coli was the most frequently isolated microorganism among uncomplicated UTIs, consistent with global epidemiology. Compared with previous local studies, there was an increase in resistance to aminopenicillins (31.6%), fluoroquinolones (26.2%), and trimethoprim-sulfamethoxazole (23.8%), emphasizing the need to reassess current empirical treatment strategies.