1696. Urinary tract infection due to Aerococcus urinae in children

BACKGROUND: Aerococcus urinae is a rare Gram-positive and catalase-negative coccus. A. urinae is primarily associated with urinary tract infection (UTI). It is responsible for urosepsis and occasionally complicated diseases, including endocarditis and osteomyelitis. The clinical presentations of adult patients with A. urinae have been described. However, there are very few reports in children. The clinical course of UTI due to A. urinae and the associated risk factors remain unclear. The aim of this study was to describe the clinical characteristics of UTI due to A. urinae in children. METHODS: We conducted a retrospective observational study at a tertiary children’s hospital in Tokyo, Japan. We included pediatric patients (< 18 years old) who had positive urine cultures for A. urinae (≥ 10(4) CFU/HPF) between June 1, 2006, and May 31, 2022. Information regarding clinical characteristics, including age, sex, underlying disease, laboratory test results, antibiotic susceptibility of A. urinae, treatment, and outcomes were collected from the electronic medical records. RESULTS: A total of 22,769 urine cultures were submitted during the study period, of which A. urinae was isolated in 35 (0.15%). We found 17 patients who were positive for A. urinae with greater than 10(4) CFU/HPF. Among them, 13 patients (76.5%) were male and 16 (94.1%) had underlying bladder dysfunction. The main clinical symptoms were fever (n=6, 35.3%), urine odor (n=4, 23.5%), and nausea (n=2, 11.8%). Five patients had diagnosed pyelonephritis due to A. urinae. All five patients were male, and the median age at presentation was 4.6 years (range 2.1-11.0 years). Four of them had underlying bladder dysfunction. All bacterial isolates were susceptible to the majority of antibiotics, including penicillin G, sulfamethoxazole, or ciprofloxacin. All patients had favorable outcomes following 10-14 days of ampicillin/amoxicillin-based antimicrobial therapy. CONCLUSION: A. urinae was isolated in urine cultures primarily in male patients with underlying bladder dysfunction. All of the outcomes of antibiotic treatment were favorable. DISCLOSURES: Kensuke Shoji, MD, PhD, AstraZeneca K.K.: Honoraria|Gilead Sciences, Inc.: Honoraria|KYORIN Pharmaceutical Co.,Ltd.: Honoraria|Meiji Seika Pharma Co., Ltd.: Honoraria|Nippon Becton Dickinson Company, Ltd.: Honoraria|Novartis Pharma Co., Ltd.: Honoraria|Viatrs, Inc: Honoraria chikara Ogimi, MD, bioMerieux Japan Ltd.: Honoraria|Horiba: Honoraria|Pfizer: Honoraria