RESUMEN
Urinary tract infections [UTIs] are one of the most frequent bacterial infections in children. Most commonly, members of Enterobacteriacea, particularly uropathogenic strains of E. coli and Enterobacter spp. are the primary causative organisms of UTIs in different parts of the world. A total of 55 hospitals from 12 provinces in Iran participated in this study. 1696 children with UTI aged 0 to 5 years referred to these hospitals were included in this study. Urine cultures were carried out and the isolates were identified by gram staining and conventional biochemical methods. Antimicrobial susceptibility testing was performed by disk diffusion method according to the current National Committee for Clinical Laboratory Standards [NCCLS] guidelines. In general 438 urine isolates were obtained. E. coli was the most frequently occurring pathogen [54.80%], followed by Klebsiella pneumoniae [16.0%], coagulase negative Staphylococci [11.2%], Enterobacter spp. [9.6%], Proteus spp. 1.4% and P. aeruginosa [1.4%]. Resistance rates of E. coli isolates were 85.9% to co-trimoxazole, 80.0% to penicillin, 77.0% to ampicillin, 68.0% to chloramphenicol, 12.9% to ciprofloxacin, 12.9% to ceftriaxone, 12.9% to cephalotin, and 14.0% to amikacin. K. pneumoniae isolates were 18.5%, 20.0%, 24.0% and 29.0% resistant to cephalothin, ceftriaxone, amikacin and gentamicin respectively; however, penicillin [88.5%], co-trimoxazole [74.2%], and ampicillin [68.5%] were the least effective drugs. High prevalence of drug-resistant urinary tract pathogens, particularly to ampicillin and co-trimoxazole among Iranian children suggests cautious use of antibiotic therapy for the treatment. Finally, we suggest that empirical antibiotic selection should be based on knowledge of the local prevalence of bacterial organisms and antibiotic sensitivities rather than on universal guidelines