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
Session: Poster Abstract Session: Urinary Tract Infection
Friday, October 5, 2018
Room: S Poster Hall
  • Triple resistance UTI Final v2.pdf (298.6 kB)
  • 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 U.S. 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 non-duplicate 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 (%)


    Fail %

    P value

    N (%)


    Fail %

    P value











    1,771 (32)




    1,627 (30)




    3-4 class resistance*

    197 (4)



    184 (3)



    *all resistant to quinolones, T/S, and β-lactams; 4 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. 

    Michael Dunne, MD1, Vikas Gupta, PharmD, BCPS2, Steven Aronin, MD1 and Sailaja Puttagunta, MD1, (1)Iterum Therapeutics, Old Saybrook, CT, (2)Becton, Dickinson and Company, Franklin Lakes, NJ


    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 .

    Findings in the abstracts are embargoed until 12:01 a.m. PDT, Wednesday Oct. 3rd with the exception of research findings presented at the IDWeek press conferences.