845 - Trends and Regional Differences in Community-Onset Fluoroquinolone-Resistant E. coli in Hospitalized Adults in the United States

Background: Escherichia coli is a common cause of community-onset (CO) infections, including urinary tract and abdominal infections, and CO sepsis.  Fluoroquinolones (FQ) are used in the empiric treatment of E. coli infections, but FQ-resistance may limit their effectiveness. We examined trends and regional differences in FQ-resistant E. coli clinical cultures among hospitalized adult patients in the U.S.

Methods: We measured the incidence of E. coli clinical cultures among hospitalized adults in a cohort of hospitals in the Premier Healthcare Database and Cerner Health Facts from 2012 through 2017. FQ resistance was defined as resistance to ciprofloxacin, levofloxacin, or moxifloxacin. Only cultures collected prior to day 4 of hospitalization, defined as CO, were considered. We extrapolated national estimates using a raking procedure to generate weighted adjustments matching the American Hospital Association distribution for U.S. acute care hospitals. Weights were based on U.S. census division, bed size category, teaching status, and urban/rural designation. We used a weighted means survey procedure to calculate national estimates and weighted multivariable logistic regression to examine trends and regional differences.

Results: In 2017, we estimated 949,393 CO E. coli infections with FQ susceptibility testing; 312,304 (33%) were due to E. coli resistant to FQ. Of FQ-resistant E. coli isolates, 76% were isolated from urine. We did not observe a significant trend in FQ-resistant E. coli from 2012 to 2017 (p = 0.85). Percent FQ-resistant varied significantly by region (p < 0.0001) with an estimated range of 19% (Mountain) to 42% (Southeast Central) in 2017.  We also found variability by hospital (2017 Q1: 26% and Q3: 39%).  FQ-resistance rates were higher in urine (36%: 95% CI 34-38%) than blood isolates (27%: 95% CI 26-29%) and higher for males (40%: 95% CI 38-42%) than females (33%: 95% CI 31-35%).

Conclusion: FQ-resistance is common in CO E. coli infections with significant variability by region and hospital. Empiric FQ treatment for infectious syndromes commonly caused by E. coli may need to be reconsidered. Clinicians should consult with local antibiograms and antibiotic stewardship programs to determine the most appropriate empiric treatment of E. coli infections in hospitalized adults.