Vol.76 No.1

　Objective: To investigate the epidemiology and antibiogram of the extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (ESBL-EC) isolated from urine samples collected from an acute-care hospital in Japan.
　Methods: A descriptive epidemiological study was conducted to compare isolates of ESBL-EC (n＝129) and non-ESBL-EC (n＝279) between April 1, 2019 and March 30, 2020. Data were collected from the microbiology laboratory and medical charts. Multivariate logistic regression analysis was used to assess patientsʼ background, infection risk factors, and ESBL-EC and non-ESBL-EC antibiograms.
　Results: E. coli was the most common bacteria (30.0%) isolated from urine samples, while urine was the most common (61.0%) source of this bacteria. Among 408 isolates of E. coli strains from urine, 129 (31.6%) ESBL-EC and 279 (68.4%) non-ESBL-EC were detected. The background investigation of patients from whom ESBL-EC was isolated revealed worsened performance status and use of antibiotics in the past two months as risk factors. Antibiogram of ESBL-EC showed high resistance to levofloxacin and third-generation cephalosporins, such as ceftazidime and cefotaxime, with high susceptibility to cefmetazole, minocycline, and fosfomycin.
　Conclusions: ESBL-EC is one of the most important multidrug-resistant bacteria, along with methicillin-resistant Staphylococcus aureus, causing serious complications in hospital settings, with antibiotic administration being a risk factor. Meropenem, cefmetazole, minocycline, or fosfomycin should be used as first-line treatment for urinary tract infections caused by ESBL-EC.