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

SummaryObjectivesThis 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.MethodsPatients 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).ResultsResistance 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).ConclusionsResistance to fluoroquinolones of E. coli is a growing problem with a negative impact on the outcome of community-acquired UTIs; therefore, the prescription of these agents should be limited to infections for which they are recommended, avoiding their use in uncomplicated UTIs.