A Study of the Changes of Antibiotic Sensitivity to the Causative Organisms of Urinary Tract Infection for Recent 5 Years

Ko, Hyeon Seung; Choi, Do Yeon; Han, Young Taik

Abstract

PURPOSE: The overuse and misuse of antimicrobial agents and their resultant emergence of resistant microorganisms have made choices regarding antimicrobial therapy more difficult. We studied the changes of antibiotic sensitivity to the causative organisms of urinary tract infection(UTI) for recent 5 years in order to give some useful informations about the choice of adequate drug in the treatment of UTI.
MATERIALS AND METHODS
We analysed 1191 uropathogens and their antibiotic sensitivities of the 1132 patients who admitted or visited the National Police Hospital and had more than 105cfu/ml on urine culture from January 1994 to December 1998 retrospectively.
RESULTS
The common pathogenic organisms were E. coli(51.5%), staphylococcus(15.7%), pseudomonas(9.1%), klebsiella(7.5%) and enterobacter(4.0%), enterococcus(3.4%), proteus(3.1%) in order. The incidence of E. coli decreased from 50.8% in 1994 to 41.3% in 1998 but the incidence of other gram negative organisms like pseudomonas, klebsiella, enterobacter, proteus and acinetobacter increased from 24.8% in 1994 to 42.6% in 1998. In E. coli isolates(the majority of positive cultures), resistance to six antibiotics changed significantly: ampicillin(19.4% to 15.5%), piperacillin(44.1% to 32.0%), cephalothin(70.6% to 58.6%), gentamicin(62.8% to 60.2%), tobramycin(95.0% to 88.1%), and ciprofloxacin(87.6% to 76.3%). The sensitivity rates of the gram negative organisms including E. coli were very low in 1998 (ampicillin 11.6%, piperacillin 36.6%, and trimethoprim/sulfamethoxazole 49.3%).
CONCLUSIONS
We think that E. coli is still the most important organism in the UTI but we shoud be concerned about the increasing incidence of other gram negative organisms like pseudomonas, klebsiella, enterobacter, proteus and acinetobacter. And prior to receiving the bacteriological report, using ampicillin, trimethoprim/sulfamethoxazole as the first choice in the treatment of UTI shoud be reconsidered.