The clinical impact of fluoroquinolone resistance in patients with E coli bacteremia

BACKGROUND: There are limited data on fluoroquinolone resistance and its impact on mortality in cases of Escherichia coli bloodstream infection (BSI). OBJECTIVE: To determine risk factors for in‐hospital mortality among patients with E coli BSIs. DESIGN: A retrospective case‐control study. SETTING: A 1250‐bed tertiary academic medical center. PATIENTS: Patients with fluoroquinolone‐resistant E coli BSI from January 1, 2000 through December 31, 2005 with 1:1 matched control patients with fluoroquinolone‐sensitive E coli BSI. INDEPENDENT OUTCOME: In‐hospital mortality. RESULTS: A total of 93 cases and 93 control patients were included. Compared with control patients, cases were more likely to be admitted from a long‐term care facility (35% vs. 9%; P < .001) and to have a hospital‐acquired bacteremia (54% vs. 33%; P = .008). Crude mortality was 26% for cases and 8% for controls ( P = .002). On univariate analysis, predictors for in‐hospital mortality included female gender, admission from a long‐term care facility, APACHE II score >10, Charlson comorbidity score >4, cardiac dysfunction, cirrhosis, renal dysfunction, treatment with corticosteroids, and a fluoroquinolone‐resistant E coli bacteremia. On multivariate analysis, independent risk factors for in‐hospital mortality were cirrhosis (adjusted odds ratio [aOR], 7.2; confidence interval [CI], 1.7–29.8; P = .007), cardiac dysfunction (aOR, 3.9; CI, 1.6–9.4; P = .003), and infection with a fluoroquinolone‐resistant E coli isolate (aOR, 3.9; CI, 1.5–10.2; P = .005). CONCLUSIONS: After controlling for severity of illness and multiple comorbidities only fluoroquinolone resistance, cirrhosis, and cardiac dysfunction independently predicted mortality in patients with E coli bacteremia. Journal of Hospital Medicine 2011;6:344–349. © 2011 Society of Hospital Medicine