Impact of Empirical and Definitive Antibiotics on Pediatric Febrile Urinary Tract Infection Caused by ESBL-Producing...

Although the clinical impact of empirical antibiotic susceptibility on urinary tract infection (UTI) caused by extended-spectrum β-lactamase-producing Enterobacterales (ESBL-PEs) is limited, the role of definitive antibiotics remains unclear. This study evaluated therapeutic outcomes and recurrence in children with febrile UTI caused by ESBL-PE, focusing on pathogen susceptibility to empirical and definitive antibiotics. Medical records of 376 UTI episodes caused by ESBL-PE in children aged <10 years were retrospectively reviewed, and 319 were analyzed. Episodes were classified as empirical-susceptible (n = 144) and empirical-non-susceptible (n = 175) groups, and further categorized into four groups based on definitive antibiotic susceptibility and treatment duration. Clinical outcomes were comparable between empirical-susceptible and empirical-non-susceptible groups. Among the four definitive-therapy groups, early clinical response did not differ significantly; however, UTI recurrence showed an increasing trend from 1.0% in those receiving empirical and definitive antibiotics to which pathogens were susceptible for ≥7 days to 6.3% in those receiving empirical antibiotics to which pathogens were non-susceptible and not receiving antibiotics to which pathogens were susceptible ≥7 days (p = 0.045). Despite favorable early response to empirical non-susceptible antibiotics, switching to susceptible antibiotics and maintaining therapy for ≥7 days is recommended for children with ESBL-PE UTIs.