A recent study on the antimicrobial sensitivity of the organisms that cause urinary tract infection

Purpose: The overuse and misuse of antimicrobial agents have made choosing an appropriate antibiotic more difficult. We studied changes in the antibiotic sensitivities of the causative microorganisms of urinary tract infection (UTI), in 2000 versus 2005, in order to provide useful information and to aid physicians to make better choices of adequate drugs for treating UTI. Materials and Methods: We retrospectively analyzed 5,266 uropathogens and their antimicrobial sensitivities in 3,346 patients who were admitted to or they had visited two tertiary hospitals located in Honam province, in 2000 versus 2005. This revealed the isolated causative organisms in the urine cultures. Results: The incidence of UTI shows bimodal peaks in the first decade (22.3%) and 7th decade (18.8%). The common pathogens were E. coli (34.4%), Enterococcus (19.0%), Staphylococcus (10.2%), Pseudomonas (9.9%) and Klebsiella (9.8%). The incidence of Gram positive organisms was increased from 35.7% in 2000 to 38.1% by 2005. For the Gram negative isolates, imipenem and amikacin showed relatively higher sensitivity, while ampicillin and ciprofloxacin showed relatively lower sensitivity. For the Gram positive isolates, vancomycin and teicoplanin showed relatively higher sensitivity, while penicillin and ciprofloxacin showed relatively lower sensitivity. Significant declines for the third-generation cephalosporins' and fluoquinolones' sensitivity to E. coli and Klebsiella isolates were found. Conclusions: E. coli was the most common single organism causing UTI. We should be concerned about the increase of Gram positive organisms, especially Enterococcus. The use of TMP/SMX and nitrofurantoin as the first choices of treatment for UTI should be reconsidered. It is recommended that fluoroquinolone should be restricted because of the high antibiotic resistance and the economic aspects.