Background: Urinary tract infection (UTI) is among the most common community acquired infectious disease in the outpatient department. Since treatment of outpatient UTI usually starts with an empirical antibiotic, the information regarding common causative organisms and their antibiotic susceptibility patterns is essential for appropriate selection of an empirical antibiotic. Furthermore, in the past few years, drug resistance among uropathogens has increased, resulting in more complex treatment choices. The aim of this study was to determine the antimicrobial susceptibility patterns of bacterial strains isolated from outpatients with community acquired urinary tract infections at Songklanagarind Hospital.

Methods: A retrospective study was conducted to review the medical records of outpatients from whose urine specimens bacteria were isolated  in the outpatient department of Songklanagarind Hospital during 2008.

Results: We identified 1130 patients with community-acquired urinary tract infections, of which, 642 were uncomplicated cases. Escherichia coli was the most common

(51.2%) etiologic agent isolated, followed by Klebsiella pneumoniae (8.1%). Antimicrobial susceptibility of overall uropathogens to norfloxacin, ampicillin, and

co-trimoxazole were 60.0%, 27.7%, and 48.4% respectively. The common factors associated with antimicrobial susceptibility to ceftriaxone, norfloxacin and

co-trimoxazole were prior antibiotic administrations, and a prior history of UTI.

Conclusions: Current data on the prevalence of antimicrobial susceptibility among urinary tract isolates should be a consideration to changing the current empiric treatment of urinary tract infections.