1527. The Prevalence of Enterobacteriaceae (ENT) Resistant to All Major Classes of Oral Antibiotics from Outpatient Urine Cultures in the United States and Effect on Clinical Outcomes

BACKGROUND: Over 99% of all outpatient urinary tract infections (UTI) in the United States are treated with either a quinolone, β-lactam, trimethoprim-sulfamethoxazole (T/S) or nitrofurantoin (NFH). Resistance to all classes of antibiotics is now reported in the US, making the selection of empiric oral therapy increasingly unlikely to cover the offending uropathogen. METHODS: We queried the BD Insights Research Database (Franklin Lakes, NJ) to evaluate ambulatory antibiotic fill history for patients from 15 US institutions with an ambulatory urine culture positive for ≥10(3) CFU/mL of an ENT. Patients who filled a prescription for an oral antibiotic were further categorized into those with a urine culture positive for a susceptible or non-susceptible (NS) pathogen. ESBL positivity was presumed if the isolate was NS to extended spectrum cephalosporins. Outcome was assessed using two surrogate endpoints: hospital admission, or a follow-up oral antibiotic within 28 days of initial antibiotic fill. Urine 30 day nonduplicate ambulatory three drug resistance rates in Q2 2017 were determined by zip code for 379 facilities. RESULTS: 48/5,587 (0.9%) episodes of UTI with an outpatient urine culture had an Enterobacteriaceae that was resistant to quinolones, T/S, and NFH, and was ESBL-positive. Of those with at least three-drug class resistance, the hospital admission rate was 28%. CONCLUSION: Multiclass resistance to existing oral antibiotics is prevalent throughout the United States in patients for whom an outpatient urine culture is available, with 1% of organisms resistant to all commonly available oral classes. Multidrug resistance in patients with an outpatient urine culture is associated with a significantly increased risk of treatment failure and subsequent hospitalization. DISCLOSURES: M. Dunne, Iterum Therapeutics: Employee and Shareholder, Salary. V. Gupta, Melinta Therapeutics, Inc.: Research Contractor, Research support. S. Aronin, Iterum Therapeutics: Employee and Shareholder, Salary. S. Puttagunta, Iterum Therapeutics: Employee and Shareholder, Salary.