Etiology and antimicrobial resistance in pediatric urinary tract infections: a 10-year retrospective study in Hohhot, China

Abstract

Introduction: Urinary tract infections (UTIs) are among the most common bacterial infections in children, yet regional pathogen distribution and antimicrobial resistance patterns remain understudied in resource-limited settings. This study aimed to characterize UTI pathogens and their resistance profiles in Hohhot, China, including molecular analysis of the YadC gene in Escherichia coli (E. coli).

Methodology: This was a retrospective analysis of 550 pediatric UTI cases from December 2014 to December 2024. Urine cultures, antimicrobial susceptibility testing, and YadC gene detection (polymerase chain reaction, PCR) for 46 E. coli isolates were performed in 2023. Statistical analysis used χ² tests or Fisher's exact tests (SPSS 27.0; p < 0.05).

Results: Among 312 culture-positive cases (56.7%), Gram-negative bacteria (64.1%, predominantly E. coli [41.7%]), Gram-positive bacteria (35.3%, mainly Enterococcus faecium (E. faecium) [20.2%]), and 2 yeast isolates (Candida tropicalis and Candida albicans; 1 strain each; 0.6%) were identified. YadC-positive E. coli isolates exhibited a significantly higher rate of multidrug resistance compared to YadC-negative isolates (83.3% vs. 37.5%, p = 0.002). Resistance rates exceeded 70% for penicillin and erythromycin in E. faecium, while E. coli showed high resistance to ampicillin/sulbactam (73.1%) and third-generation cephalosporins. Nitrofurantoin and β-lactam/β-lactamase inhibitors (e.g., ampicillin/sulbactam) remained effective for E. faecalis isolates.

Conclusions: E. coli remains the predominant UTI pathogen in Hohhot. The high YadC prevalence (65.2%) and its association with cephalosporin resistance indicate its surveillance potential. Empirical therapy should favor agents like ceftazidime, while managing complicated UTIs requires integrating imaging and susceptibility testing to curb resistance and prevent renal injury.