[Changes in the antimicrobial susceptibility of Escherichia coli isolates from community diagnosed urinary tract infections during the period 2003-2007. Multicentre study in Castilla la Mancha (Spain)].

OBJECTIVE To know the evolution of susceptibility patterns of Escherichia coli in patients with community diagnosed urinary tract infections (UTIs) during last years in Castilla la Mancha (Spain). METHODS Descriptive and retrospective study performed between january 2003 and december 2007. We studied data about frequency and susceptibility of 33.651 E. coli isolates from urine cultures that were remited from primary care centres depending of 6 hospitals in Castilla la Mancha (Spain). RESULTS Susceptibility rates of E. coli for most antibiotics decreased significantly during the 5-year period, especially for amoxicillin-clavulanic acid, cefuroxime and quinolones. Average rates of susceptibility for amoxicillin-clavulanic acid, ciprofloxacin, cefuroxime, fosfomycin and nitrofurantoin were: 86.7, 75.4, 87.3, 97.6 and 96.2%, respectively. We observed a significantly increase of E. coli isolates producing extended-spectrum betalactamases ESBLs), from 1.9% in 2003 to 4,9% in 2007 (χ² TL = 143.6, p<0.001). CONCLUSIONS We observed a significantly reduction of E. coli susceptibility for most antibiotics and an increase of E. coli isolates producing ESBLs. Fosfomycin and nitrofurantoin are the best choices for empiric treatment. Prospective studies should be performed in the future to confirm the results of our study.