Background: Resistant organisms are now a growing and frequent problem in community-acquired infections. There is little information on the etiology and antimicrobial susceptibility patterns of community-acquired urinary tract infection (CA-UTI) at a tertiary-care hospital.

Methods: We evaluated the distribution of etiological organisms with their antimicrobial susceptibility patterns of CA-UTI in the patients visiting a tertiary-care hospital during the period of three years from 2001 through 2003.

Results: In total, 1,753 bacterial isolates yielded a significant growth as pathogens of CA-UTI in this study. The most common pathogen was Escherichia coli(38.3%), followed by Pseudomonas aeruginosa(10.8%), Enterococcus faecalis(7.3%), Klebsiella pneumoniae(6.4%), coagulase negative staphylococci (CoNS) (5.4%) and Staphylococcus aureus(5.2%). The prevalence of E. coli was significantly higher in females (P< 0.001), whereas P. aeruginosa, E. faecalis,and S. aureus were significantly more common in male group (P< 0.001). The susceptibility rate of E. coli was 26.0% to ampicillin, 65.8% to gentamicin, 51.3% to co-trimoxazole, and 62.5% to ciprofloxacin. The susceptibility patterns of Enterobacteriaceae other than E. coli were different from those of E. coli. Extended spectrum beta-lactamase was detected in 7.9% of E. coli and 15.6% of K. pneumoniae.

Conclusion: This study demonstrates a diversity of etiological organisms and a high rate of resistance to commonly used antimicrobials of CA-UTI in patients visiting a tertiary-care hospital. (Korean J Clin Microbiol 2005;8(2):142-147)