Uncomplicated urinary tract infections. Antimicrobial susceptibility study in Navarre

Background. Urinary tract infection (UTI) is a high prevalence infection at the community level. In order to improve the adequacy of the empirical therapy, we evaluated the etiology and the resistance pattern of the main uropathogens responsible for community acquired UTI in Navarre. Methods. Retrospective study (2014-2016) in which we included microorganisms recovered with significant counts from samples of patients with community-acquired UTI. The global etiology and etiology according to age and sex was analyzed. Antimicrobial resistance was studied with urotopathogens isolated in 2016. Results. Escherichia coli was the most frequently isolated microorganism both in the population (60.8%) and in each of the groups analyzed according to age and sex. The sensitivity of E. coli was: nitrofurantoin 97.4%, fosfomycin 96.5% amoxicillin-clavulanic acid 83.8%, trimethoprim-sulfamethoxazole 68.3%, quinolones 63.4% and amoxicillin 41.9%. Pooled sensitivity shows that the sensitivity to fosfomycin was 83.4% in men <15 years, 89.4% in women <15 years and 81.9% in women between 15-65 years; and to nitrofurantoin was 86.7% in women <15 years and 82.2% in women between 15-65 years. Conclusions. E. coli continues to be the most frequent microorganism in community-acquired UTI with a rate of sensitivity to fosfomycin and nitrofurantoin above 95%. The empirical treatment of UTI in our environment should not include amoxicillin, amoxicillin-clavulanic acid, trimethoprim-sulfamethoxazole or quinolones. Fosfomycin may be empirically used in the treatment of uncomplicated cystitis in men younger than 15 years and in women under 65 years, and nitrofurantoin may be used empirically in women under 65 years.