Department of Infectious Diseases, Institute of Biomedicine, The Sahlgrenska Academy and Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, Gothenburg, Sweden; Department of Clinical Microbiology, Sahlgrenska University Hospital, Gothenburg, Sweden.
Department of Infectious Diseases, Institute of Biomedicine, The Sahlgrenska Academy and Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, Gothenburg, Sweden; Department of Clinical Microbiology, Sahlgrenska University Hospital, Gothenburg, Sweden.
J Glob Antimicrob Resist. 2020 Sep;22:126-132. doi: 10.1016/j.jgar.2020.01.024. Epub 2020 Feb 12.
Bacterial features associated with recurrent urinary tract infections (RUTIs) due to extended-spectrum β-lactamase-producingEscherichia coli (ESBL-E. coli) are not well understood. In this study, phylogenetic groups and ST131 subclones were investigated to assess strain homology of ESBL-E. coli isolates in patients with RUTIs in inpatient and outpatient settings in western Sweden.
Almost all isolates (319/356) from 123 patients with 2-7 episodes (median 2 episodes) of ESBL-E. coli UTI within 1 year were examined for seven E. coli phylogroups, the ST131-O25b clone and its subclone fimH30-Rx. Antimicrobial resistance and ESBL genes were determined for the index isolates. A subset of isolates was typed using pulsed-field gel electrophoresis (PFGE).
The same phylogroup and ST131 subclones were seen for all recurrences in 119/123 patients, and PFGE confirmed strain homology in recurrences for 43/44 patients tested. Phylogroup B2 dominated (56%), followed by D (19%) and F (10%). ST131-O25b andfimH30-Rx isolates were detected in 44% and 30%, respectively. CTX-M group 1 (71%) predominated. Elderly patients were in the majority. There were no associations between patient demographics or time to recurrence and bacterial characteristics. The fimH30-Rx subclone was associated with a higher number of recurrences (P = 0.015) compared with the remaining B2 isolates.
In ESBL-E. coli RUTI, most recurrences were caused by the initial infecting strain. The high frequency of the multidrug-resistant fimH30-Rx subclone and its association with multiple recurrences warrants further attention and early detection of this subclone in patients at risk of developing RUTI with ESBL-E. coli.
由产超广谱β-内酰胺酶的大肠杆菌（ESBL-E. coli）引起的复发性尿路感染（RUTI）的细菌特征尚不清楚。本研究调查了进化枝群和 ST131 亚克隆，以评估在瑞典西部住院和门诊环境中患有 RUTI 的患者中 ESBL-E. coli 分离株的菌株同源性。
对 123 名患者的 319/356 株（中位数为 2 次发作）的 ESBL-E. coli UTI 进行了 2-7 次发作（中位数为 2 次），检查了 7 株大肠杆菌进化枝群、ST131-O25b 克隆及其 fimH30-Rx 亚克隆。对指数分离株进行了抗生素耐药性和 ESBL 基因的测定。使用脉冲场凝胶电泳（PFGE）对分离株进行了亚型分析。
在 119/123 名患者的所有复发中都观察到相同的进化枝群和 ST131 亚克隆，44 名经测试的患者中有 43 名的 PFGE 证实了复发的菌株同源性。进化枝群 B2 占主导地位（56%），其次是 D（19%）和 F（10%）。检测到 ST131-O25b 和 fimH30-Rx 分离株分别为 44%和 30%。CTX-M 组 1（71%）占主导地位。老年患者居多。患者的人口统计学特征或复发时间与细菌特征之间无关联。与其余 B2 分离株相比，fimH30-Rx 亚克隆与更多的复发次数相关（P=0.015）。
在 ESBL-E. coli RUTI 中，大多数复发是由初始感染株引起的。多药耐药的 fimH30-Rx 亚克隆的高频率及其与多次复发的关联值得进一步关注，并应早期检测出有发生 ESBL-E. coli 引起的 RUTI 风险的患者中的这种亚克隆。
