Resistance to fluoroquinolones and treatment failure/short-term relapse of community-acquired urinary tract infections caused by Escherichia coli

Objectives: This study aims to evaluate the impact of resistance to fluoroquinolones on the short-term outcome of community-acquired urinary tract infections (UTIs) caused by Escherichia coli. Methods: Patients were identified and followed, during 2006, using the health care databases of the Emilia-Romagna Region. The outcome of interest was the treatment failure/short-term relapse (the re-isolation of E. coli from urine between 4 and 30 days after the first isolation). Results: Resistance to fluoroquinolones increases the risk of treatment failure/short-term relapse in women with uncomplicated community-acquired UTIs caused by E. coli (Rate Ratio = 1.85, 95% CI 1.32-2.60). The efficacy of fluoroquinolones for community-acquired UTIs of men was significantly modified by the resistance status of E. coli. Prescription of these agents was associated with a reduced occurrence of the outcome only in men with a ciprofloxacin sensitive first isolate (Rate Ratio = 0.50, 95% CI 0.25-0.99). Conclusions: Resistance to fluoroquinolones of E. coli is a growing problem with a negative impact on the outcome of comm unity-acquired UTIs; therefore, the prescription of these agents should be limited to infections for which they are recommended, avoiding their use in uncomplicated UTIs. (c) 2008 The British Infection Society. Published by Elsevier Ltd. All rights reserved.