PEDIATRIC URINARY TRACT INFECTION MANAGEMENT IN THE ERA OF RISING ANTIBIOTIC RESISTANCE: INSIGHTS FROM A SINGLE-CENTER COHORT

Objective: Urinary tract infections (UTIs) are one of the most common bacterial infections in children and can lead to serious complications. This study aimed to investigate the clinical and microbiological characteristics of pediatric UTIs, identify factors associated with renal scarring, analyze trends in antibiotic resistance, and evaluate the impact of urinary anomalies and vesicoureteral reflux (VUR) on recurrence of infection and long-term outcomes.Material and Methods: In this retrospective study, 699 children followed up for UTI were evaluated. Clinical features, laboratory and imaging findings (Ultrasound, voiding cystourethrogram, DMSA renal scan), microbiological data, antibiotic resistance patterns and long-term complications were analyzed. Risk factors for renal scarring were assessed using multivariate logistic regression.Results: Out of the 699 patients followed for UTIs, 530 were female. The median age at the first UTI was 12 months. Renal ultrasonography was performed on all patients. Anomalies were detected in 15.7% of patients. E. coli was the predominant pathogen (82.6%). Renal scarring was detected in 15.7% of patients and was significantly associated with high-grade VUR, recurrent UTI, abnormal US findings, and fever ≥38°C. The prevalence of ESBL-producing bacteria was 2.4%, with ubstantialtly higher ciprofloxacin resistance (28%) compared to non-ESBL bacteria (7.5%). Over time, E. coli resistance to TMP-SMX and amoxicillin-clavulanate declined, whereas cefixime resistance slightly increased.Conclusion: Renal scarring in pediatric UTI is strongly associated with VUR severity, recurrent infections, and urinary tract anomalies. Antibiotic resistance remains a growing concern, particularly among ESBL-producing pathogens. Rational use of antibiotics and individualized risk-based prophylactic strategies are critical to minimizing long-term complications and resistance.