1465. Resistance to Oral Antibiotics Among Urinary Tract Infection Isolates of Escherichia coli from the United States and Europe in 2017

Abstract

BackgroundClinical guidelines have recommended oral antibiotics such as the cephalosporins, fluoroquinolones, and trimethoprim-sulfamethoxazole (TMP-SMX) for the treatment of urinary tract infections (UTI’s) caused by Escherichia coli (EC). The utility of these agents continues to be eroded by increased prevalence of expanded spectrum β-lactamase (ESBL) genes and concomitant resistance determinants to other antimicrobial classes. This study assessed the prevalence of ESBL phenotypes among EC from UTIs in the United States and 11 countries in Europe (EU) in 2017 and the impact of co-resistance to oral agents used to treat UTIs.Methods2422 unique EC from UTIs in the United States and EU in the SENTRY Surveillance program were evaluated for susceptibility to various agents. All isolates were consecutively collected and centrally tested by CLSI methods and interpretive criteria. Isolates that met ESBL MIC screening criteria were characterized for the presence of β-lactamase genes.ResultsAmong the 2422 isolates of EC from UTI’s in the United States and EU the resistance (R) rates for cefuroxime (CEF), levofloxacin (LEV) and TMP-SMX were 17.9%, 25.6% and 33.2%, respectively. The overall prevalence of ESBL phenotypes was 18.2% (18.7% in the United States and 21.0% in EU). Among the 411 ESBL phenotypes, R to CEF, LEV and TMP-SMX were: 94.3%, 70.6%, and 61.6%, respectively. In contrast, <0.1% of all EC or 0.2% of ESBL EC were meropenem (MER)-R. Only two carbapenemase-producing organisms were identified, an NDM-5- and a KPC-2-producing EC from Turkey and Greece, respectively. The CTX-M-15 was the most prevalent ESBL and identified among 167 isolates; with co-resistance to CEF, LEV and TMP-SMX noted in 100%, 82.6% and 70.7%, respectively. All CTX-M-15 isolates were susceptible to MER.ConclusionOral agents such as CEF, LEV, and TMP-SMX exhibit R rates ≥17.9%. Co-resistance to CEF, LEV, and TMP-SMX were considerably higher among ESBL phenotypes (>61.1%) and confirmed blaCTX-M-15 genotypes (70.7%). In contrast, the carbapenems remained active against ESBL phenotypes and genotypes, such as blaCTX-M-15. New oral agents with the spectrum and potency of the carbapenems would address an unmet need for new options to treat multi-drug-resistant EC UTIs.Disclosures All authors: No reported disclosures.