P-1470. Single-dose Aminoglycosides versus Carbapenems for the Treatment of Uncomplicated Urinary Tract Infections caused by Extended-spectrum Beta-lactamase-phenotype <i>Enterobacterales</i>

Abstract Background Carbapenems are often used for treatment of infections caused by extended-spectrum β-lactamase-producing (ESBL) Enterobacterales. Over utilization has led to carbapenem resistance and these infections can be difficult to treat. Limiting unnecessary carbapenem exposure has been shown to decrease the risk of carbapenem resistance and a 2023 Infectious Disease Society of America guidance document recommends non-carbapenem alternatives for the treatment of uncomplicated urinary tract infections (uUTI). A single dose of an aminoglycoside (AG) can be considered, however clinical trial data is lacking, especially for those with infections caused by drug-resistant pathogens. Methods A retrospective, multi-center, cohort study over 60-months evaluated hospitalized patients within the NYU Langone Health System ≥18 years of age who received a single dose of an AG for the treatment of an uUTI caused by an AG-susceptible, ESBL-phenotype (defined as ceftriaxone MIC ≥2 mcg/mL) gram-negative bacilli (GNB). Patients who received MEM for ≥72 hours were the active comparator. Clinical success, a composite of the following, was assessed at Day 7 (±2 days) post-therapy or at discharge, whichever occurred sooner: clinical cure, defined as complete resolution or significant improvement of baseline uUTI signs/symptoms; microbiological response, defined as reduction in baseline uropathogen to &amp;lt; 103 CFU/mL. To demonstrate non-inferiority, 352 patients were needed to achieve 90% power. Results Baseline characteristics can be found in Table 1. Clinical success occurred in 97% (N=37) vs. 86% (N=129) of patients treated with an AG vs. MEM, respectively (p=0.052). Non-inferiority was met with a 0.11 proportion difference in clinical success (90% confidence interval [-0.011, 0.25]) within the predefined non-inferiority limit. No statistically significant differences in secondary outcomes were observed (Table 2). Diarrhea was more common in those treated with MEM (p=0.049; Table 3). Conclusion Single dose AG demonstrated comparable clinical success and recurrence rates to MEM for the treatment of uUTI caused by ESBL-producing GNB. The study was underpowered, increasing the chance for type II error. A future prospective study is warranted to justify preliminary findings. Disclosures Michael Bosco, PharmD, BCIDP, AAHIVP, Shionogi Inc: Advisor/Consultant|Shionogi Inc: Grant/Research Support