Molecular Epidemiological Characterization of Uropathogenic Escherichia coli From An Outpatient Urology Clinic in Nagano, Japan

An increasing prevalence of multidrug-resistant Escherichia coli causing extraintestinal infections is a growing public health concern. The prevalence in a hospital or community of drug-resistant urinary tract infection (UTI) is greatly affected by clonal composition of uropathogenic drug-resistant E. coli strains. We assessed the clonality and diversity of UTI-causing E. coli in one rural community in Japan. Patients presenting to a private urology clinic located in a rural community with UTI and no underlying medical conditions were recruited from Oct 2008 to Aug 2009. Participants provided a urine sample and completed a questionnaire regarding demographic and clinical information. Antibiotic susceptibility test and multilocus sequence typing of all E. coli isolates were performed. Of 136 patients with UTI, 81 (59.5%) were infected with E. coli; 5 had trimethoprim-sulfamethoxazole resistance (6.2%) and 4 had levofloxacin resistance (4.9%). 41 of the 81 isolates comprised 5 distinct clonal complexes (Cplx). ST95 Cplx accounted for 24.7% (n=20), ST131 Cplx for 8.6% (n=7), ST357 Cplx for 7.4% (n=6), ST73 Cplx for 6.2% (n=5), and ST69 Cplx for 3.7% (n=3) of all E. coli isolates. The high clonality among the isolated E. coli from epidemiologically unrelated patients in a community suggests a spread of certain strains by routes other than hospital-associated person-to-person transmission. Since ST95, ST131 and ST69 Cplx are well documented global epidemic multidrug-resistant or food animal related E. coli strains, our findings further support the notion that global food trade may be contributing to the spread of these strains.