Molecular Epidemiological Characterization of Uropathogenic Escherichia coli from an Outpatient Urology Clinic in Rural Japan

Abstract

gIn the remote Japanese community of Saku, a rural town in the Nagano Prefecture, a large proportion of outpatient urinary tract infections was caused by well-recognized globally dispersed clonal lineages of uropathogenic Escherichia coli (UPEC). However, most of these strains were drug susceptible, suggesting that factors other than selection pressure account for the clonal spread of drug-susceptible UPEC. In Japan, most characterizations of uropathogenic Escherichia coli (UPEC) strains have been limited to hospital settings where the proportion of drug-resistant strains may be higher than that in community-associated UPEC strains (1-4). Therefore, to assess the prevalence of antimicrobial resistance and the clonal composition of UPEC in a community setting, we studied patients at an outpatient clinic in Saku, a remote rural town in the Nagano Prefecture of Japan.Patients presenting to the clinic between October 2008 and September 2009 with clinically suspected urinary tract infection (UTI) and the presence of pyuria were recruited into the study. All men and women reporting any urinary tract abnormality, history of urinary catheter use, cancer, diabetes, or other medical condition requiring hospitalization were classified as having a complicated UTI. Women without these features were classified as having an uncomplicated UTI. Patients also completed a questionnaire which included various medical, exposure, and demographic questions. Each patient provided written informed consent to participate. Approval was obtained from the institutional review board of the National Institute of Infectious Diseases, Japan. Antimicrobial susceptibility testing was performed for all E. coli isolates with the Vitek 2 compact system (bioMérieux, Marcy l'Etoile, France) according to the manufacturer's instructions. The antimicrobial agents tested were cefazolin, cefotiam, ceftriaxone, piperacillin-tazobactam, levofloxacin, and trimethoprimsulfamethoxazole (SXT). An isolate was considered to be multidrug resistant if it exhibited nonsusceptibility to at least one agent in three or more antimicrobial categories (5). Each E. coli isolate was typed by multilocus sequence typing (MLST). MLST was performed according to the protocol described on the University of Warwick MLST database website (http://mlst.warwick.ac.uk /mlst/). Allelic profiles and sequence types (ST) were assigned according to the aforementioned website's scheme. Clonal complexes (CCs) were defined as groups of isolates with an identical ST or one or two allele differences from another ST within the CC. The risk factors were compared by assessing odds ratios (OR) with 95% Cornfield approximation confidence intervals (CI). Statistical significance was defined as a P value of Ͻ0.05.Among 199 participants, 129 completed the questionnaire. Of these, 114 (88%) were women and 15 (12%) were men; 99 (77%) had an uncomplicated UTI, whereas 30 (23%) had a complicated UTI. Patients who had diarrhea during the 6-month period prior to the current UTI and patients who lived in a hous...

Epidemiology and genotypic characterisation of dissemination patterns of uropathogenicEscherichia coliin a community

“…Moreover, ST95 and ST73, both HIF STs, had lower resistance rates than non-HIF STs, which indicates that antimicrobial resistance is not always required to become a common ST. This finding is consistent with previous reports [ 24 , 30 ], in which ST95 was the most common genotype and the strains of ST95 were mostly susceptible to all tested drugs. The prevalence of drug-susceptible isolates of ST95, ST73 and ST357, which together accounted for 57% (74/129) of all susceptible isolates, appears to have lowered the overall rate of antimicrobial resistance (22.3%) of the UPEC isolates.…”

“…UPEC strains can be transmitted via water, food [ 25 ], or through person-to-person contact [ 5 , 27 , 28 ]. However, the water supply in Takikawa is monitored strictly according to the Drinking Water Quality Standards of Japan, which includes ‘ E. coli , not to be detected.’ Although previous studies [ 29 , 30 ] reinforced within-household transmission, the absence of geographical case concentration suggested that acute UTIs less frequently occurred in women living together with the patients than expected. This can be explained partly by the growing trend toward living in nuclear families (i.e., small family size) and by a feature of the pathogenesis of acute UTIs.…”

Persistent Pandemic Lineages of Uropathogenic Escherichia coli in a College Community from 1999 to 2017

“…Interestingly, these same genotypes (ST95, ST127, ST73, ST69, ST131, and ST10) account for a large proportion of both CA-UTI and bloodstream infections (BSI) in many other communities around the world (12)(13)(14)(26)(27)(28). The predominance of these major genotypes varies geographically.…”