Background: PRONARES (Programa Nacional de Vigilancia Cie Resistencia) is a national surveillance Program for antimicrobial susceptibility, focused in different among these, urinary, tract infections. The work, is done in a laboratory net that uses Common protocols and whose data are centrally analyzed using the WHONET program, Aim: To analyze the pattern of antimicrobial susceptibility of agents causing urinary infections in children in the period 1997-1999, Material and methods: fit the study period, 5,525 strains were analyzed. Of these, 2,307 came from pediatric patients (1,495 bospitalized and 803 ambulatory). Results: The most common causative agent was E. coli in 74,2% of cases, followed by Klebsiella spp in 8,2% and other agents in a lower frequency. Of E. coli strains, 74% were resistant to ampicillin, 52% to clotrimoxazole and 30% to first generation cephalosporins. These strains were, sensitive to second aad third generation cephalosporins, aminoglycosides, ciprofloxacin and nitrofurantoin. Strains from nosocomial or community infections had similar antimicrobial susceptibility. Klebsiella spp had a high rate of antimicrobial resistance (over 40%), that was even higher among nosocomial strains. It was 90% Susceptible to ciprofloxacin and 100% to imipenem. All centers from which strains came had a similar pattern of susceptibility, with the exception of a pediatric center that had significantly higher resistance levels. Conclusions: The current therapeutic recommendations for urinary tract infections in children Caused by E Coli, are still pertinent, but the use of first generation cephalosporins must be cautious. The treatment of Klebsiella spp requires an individual antibiogram (Rev Med Chile 2001; 129: 877-885).
