Pediatric urinary tract infection: antimicrobial susceptibility profile and resistance-associated factors in a pediatric hospital in São Paulo, Brazil.

Objective: Urinary tract infections (UTIs) are among the most common bacterial infections in childhood and a frequent cause of morbidity and antibiotic use. The aim of this study was to identify urinary pathogens in children and adolescents, assess antimicrobial resistance patterns, and analyze their correlation with clinical factors.

Methods: This observational and retrospective study was conducted in a pediatric hospital from January 1 to December 31, 2022, including patients with positive urine cultures.

Results: A total of 894 cases were analyzed, mostly children aged 1 to 5 years (58.6%) and female (67.9%). Escherichia coli was the main pathogen (63.1%), followed by Proteus mirabilis (11.1%) and Pseudomonas aeruginosa (6.4%). E. coli showed high resistance to ampicillin (38.9%) and trimethoprim/sulfamethoxazole (14.5%), maintaining high susceptibility to second- and third-generation cephalosporins and aminoglycosides. Extended-spectrum beta-lactamase was detected in 2.8% of samples. Previous history of UTI was the only factor significantly associated with antimicrobial resistance.

Conclusions: The findings underscore the importance of continuous epidemiological surveillance to guide empirical treatment and rational antibiotic use in children.