Antimicrobial Resistance of Escherichia coli Urinary Isolates in the Veterans Affairs Health Care System

Abstract

We reviewed data for almost 300,000 clinical Escherichia coli urinary isolates (collected in 2009 through 2013) from 127 inpatient and outpatient facilities, to assess antibiotic resistance among Veterans Affairs health care system patients using Clinical and Laboratory Standards Institute and Centers for Disease Control and Prevention National Healthcare Safety Network definitions or guidance. Rates of resistance to amoxicillin or ampicillin/␤-lactamase inhibitors were approximately 40% and rates of resistance to fluoroquinolones and trimethoprim-sulfamethoxazole approached 30%. Rates of resistance to nitrofurantoin, antipseudomonal penicillin/␤-lactamase inhibitors, and carbapenems remained less than 10%. The percentage of isolates that were considered multidrug resistant varied (4% to 37%), depending on the definitions used.

Antimicrobial resistance prevalence, rates of hospitalization with septicemia and rates of mortality with sepsis in adults in different US states

“…Prevalence of resistance for certain combinations of antibiotics/bacteria not covered by the US CDC Atlas data [21] could have also contributed to the correlations found in our analysis. For example, for E. coli-associated UTIs recorded in Veterans Affairs data [26], prevalence of resistance to ampicillin/amoxicillin was higher than prevalence of resistance to fluoroquinolones, and prevalence of resistance to trimethoprim/sulfamethoxazole was also high.…”

“…Among the different combinations of bacteria/antibiotics in the CDC AR Safety Atlas data [21], prevalence of fluoroquinolone resistance in E. coli had the strongest correlation with the rates of hospitalization with septicemia in all age groups over 50y, and with the rates of mortality with sepsis in all age groups 18-84y. Additionally, E. coli is the most common source of septicemia among the bacteria covered by the CDC AR Atlas data [1], and prevalence of resistance to fluoroquinolones in E. coli isolates in both urinary tract and bloodstream infections is high in the US [17,26,27]. We also note that no data on resistance to penicillins other than methicillin are available in [21], with the use of penicillins found to to be associated with the rates of sepsis in older adults in our related work [19,20].…”

“…Among the 23-25 combinations of antibiotics/bacteria in the CDC Atlas data [21] included in the analyses for the different age groups/sepsis-related outcomes (septicemia hospitalization or sepsis mortality), prevalence of resistance to fluoroquinolones in E. coli had the highest correlation with septicemia hospitalization rates in all age groups over 50y, and the highest correlation with sepsis mortality in all age groups under 85y (Figures 1-10). Additionally, E. coli is a major source of Gram-negative septicemia in the US [1], and prevalence of resistance to fluoroquinolones in E. coli isolates in both urinary tract and bloodstream infections is high in the US [17,26,27]. We also note that no data on prevalence of resistance to penicillins (save for methicillin) are available in [21].…”

MarR family proteins are important regulators of clinically relevant antibiotic resistance

“…In the United States, about one-third of E. coli isolates are resistant to trimethoprim-sulfamethoxazole and fluoroquinolones. 10 Resistance rates against some beta-lactam drugs such as ampicillin approach 50%. These antibiotics are part of the very restricted repertoire of orally available antibiotics and are frequently used to treat common community acquired infections such as urinary tract infections.…”

“…There has been an unprecedented rise in resistance against common antibiotics among clinically relevant E. coli isolates over the last several decades. In the United States, about one‐third of E. coli isolates are resistant to trimethoprim‐sulfamethoxazole and fluoroquinolones . Resistance rates against some beta‐lactam drugs such as ampicillin approach 50%.…”