Abstract
OBJECTIVE: Urinary tract infection (UTI) is a major health concern in pediatric populations. By analysing temporal changes in pathogen distribution and antimicrobial resistance among children with UTIs in Southwest China from 2020 to 2024, we aim to provide a robust scientific basis for the empirical antibiotic therapy in this region. METHODS: We retrospectively analyzed non-duplicate pathogens isolated from urine specimens and their antimicrobial susceptibility results in 6598 children (≤14 years old) diagnosed with UTIs in southwest China from 2020 to 2024. These results were interpreted according to the M100 guidelines of the American Clinical and Laboratory Standards Institute (CLSI) and analysed using WHONET 5.6 software. RESULTS: A total of 7831 strains of pathogenic bacteria were detected, of which 60.1% were gram-negative and 39.9% were gram-positive. The top five bacteria detected were Escherichia coli (37.8%), Enterococcus faecium (26.3%), Enterococcus faecalis (7.5%), Klebsiella pneumoniae (6.9%) and Pseudomonas aeruginosa (2.5%). E. coli showed less than 10% resistance to piperacillin/tazobactam, cefoperazone/sulbactam, amikacin and nitrofurantoin, with resistance to quinolones ranging from 31.3% to 51.5%. K. pneumoniae showed resistance rates of 13.1% and 16.8% to imipenem and meropenem, respectively, from 2020 to 2024. E. faecium showed significantly higher resistance rates to the tested drugs than E. faecalis, particularly to ampicillin (95.1-97.4% vs 4.9-8.0%). Methicillin-resistant Staphylococcus aureus (MRSA) was detected at a rate of 33.8%. MRSA showed a higher level of resistance to penicillin, rifampicin, levofloxacin, clindamycin and erythromycin than methicillin-sensitive strains. CONCLUSION: Over the past five years, the main pathogenic bacteria responsible for pediatric UTIs in southwestern China were E. coli, E. faecium and E. faecalis. Resistance patterns among major uropathogens revealed diverse trends, and the emergence of multidrug-resistant organisms presents a serious therapeutic challenge that warrants close surveillance.