Urinary tract infection in urolithiasis patients: risk factor analysis, pathogen distribution, and antimicrobial resistance characteristics.

OBJECTIVE: This study investigated risk factors, pathogen distribution, and antimicrobial resistance characteristics of urinary tract infection (UTI) in patients with urolithiasis. METHODS: A retrospective analysis was conducted among 934 patients with urolithiasis treated between April 2020 and April 2025. Patients were classified into a UTI group (n = 194) and a non-UTI group (n = 740). Clinical variables, stone-related characteristics, urinary parameters, renal function indicators, urine culture results, and antimicrobial susceptibility data were analyzed. Univariate analysis and multivariate logistic regression were used to identify independent risk factors for UTI. RESULTS: Among 178 non-duplicate pathogenic isolates from the UTI group, Gram-negative bacteria predominated (68.54%), followed by Gram-positive bacteria (27.53%) and fungi (3.93%). Escherichia coli and Pseudomonas aeruginosa were the most common Gram-negative pathogens, while Enterococcus faecalis and Enterococcus faecium were the main Gram-positive pathogens. Escherichia coli showed high resistance to ampicillin, cefazolin, and ceftazidime, whereas no imipenem-resistant Escherichia coli or Pseudomonas aeruginosa isolates were detected. Multivariate logistic regression identified hydronephrosis, urinary tract obstruction, urine pH ≥ 7.0, stone diameter ≥3 mm, and serum creatinine ≥106 μmol/L as independent risk factors for UTI. CONCLUSION: Urolithiasis-associated UTI is mainly caused by Gram-negative bacteria with notable antimicrobial resistance. Early identification of high-risk patients, timely relief of obstruction, and antimicrobial therapy guided by susceptibility testing may help improve infection management.