Etiology of community-acquired lower urinary infections and antimicrobial resistance of Escherichia coli:: a national surveillance study

BACKGROUND AND OBJETIVES: The increasing rates of resistance exhibited by uropathogens represent a serious problem. The aim of this study was to determine, in Spain, the etiology of community-acquired lower urinary infections and antimicrobial resistance of Escherichia coli isolates. METHODS: Prospective multicenter study conducted between February and June 2006, in 15 microbiology laboratories located in 9 autonomous regions. RESULTS: A total of 3,109 isolates were recovered. E. coli was the most frequent (70.8%), followed by Klebsiella spp (6.8%) Proteus spp (6.6%), and Enterococcus spp (5.5%). The resistant rate of E. coli for phosphomycin was 1.7%, 3.8% nitrofurantoin, 6.9% cefexime, 8.1% amoxicillin-clavulanic 8.9% cefuroxime, and 23.9% ciprofloxacin. The 5.2% were extended-speccillin-clavulanic, spectrum beta-lactamase (ESBL)- producing microorganisms. Resistance of E. coli to ciprofloxacin was lower in people younger than 40 years (6.7% vs 33.9% in > 60, p < 0.001), and in some regions (12.5% in Galicia vs 37.3% in Valencia). ESBL-producing E.coli was higher in people older than 60 years (79.1% vs 7% in < 40, p < 0.001), and exhibited geographic variations (18.4% in Valencia, 0.8% in Galicia). The 68.6% of ESBL-producing E.coli were resistant to cotrimoxazole, 72.2% to ciprofloxacin vs 10.6% to nitrofurantoin and 1.9% to phosphomycin. CONCLUSIONS: The increasing rates of resistance and cross-resistance of this study make evident a real problem that strengthens the need for a reevaluation of the empiric treatment of lower urinary infections.