LAUSR

Abstract 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 ≥103 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%. 28-Day Prescription Fill 28-Day Readmission N (%) Failures Fail % P-Value N (%) Failures Fail % P–Value Overall 5,587 1250 22 5,395 379 7 Pan-susceptible 1,771 (32) 287 16 0.0001 1,627 (30) 124 8 0.0001 3-4 Class Resistancea 197 (4) 55 28 184 (3) 51 28 aAll resistant to quinolones, T/S, and β-lactams; four class also includes resistance to NFH.Figure: Geographic prevalence of three drug class resistance (quinolones, β-lactam, T/S) among Enterobacteriaceae causing UTI in the outpatient setting. 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.