i This study aimed to (i) investigate the antimicrobial susceptibilities of bacteria that cause urinary tract infections (UTIs) in outpatient and inpatient settings and (ii) evaluate the risk factors for emerging antimicrobial drug resistance in UTIs in South Korea. In total, 3,023 samples without duplication were collected from females between 25 and 65 years of age who had been diagnosed with a urinary tract infection. Multicenter patient data were collected using a Web-based electronic system and then evaluated. The isolation rates of Escherichia coli, Klebsiella pneumoniae, and Enterococcus faecium in the outpatient setting were 78.1, 4.7, and 1.3%, respectively; in the inpatient setting, the isolation rates of these microorganisms were 37.8, 9.9, and 14.8%, respectively. The susceptibilities of E. coli to amikacin, amoxicillin-clavulanic acid, cefotaxime, cefoxitin, ciprofloxacin, piperacillin-tazobactam, and imipenem in the outpatient setting were 99.4, 79.8, 89.4, 92.8, 69.8, 96.9, and 100.0%, respectively; in the inpatient setting, the susceptibilities to these antibiotics were 97.8, 73.9, 73.7, 82.1, 53.6, 93.2, and 100.0%, respectively. The most unique and common risk factor for emerging antimicrobial-resistant E. coli, K. pneumoniae, and E. faecium was previous exposure to antimicrobials. On the basis of these data, the use of fluoroquinolones should be reserved until culture data are available for the treatment of UTIs in South Korea. The present study will serve as a useful reference for Far Eastern Asia.
