Institute of Microbiology and Immunology, College of Life Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan.
Department of Geriatrics and Gerontology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
BMC Microbiol. 2023 Mar 30;23(1):90. doi: 10.1186/s12866-023-02820-1.
Escherichia coli is the leading pathogen responsible for urinary tract infection (UTI) and recurrent UTI (RUTI). Few studies have dealt with the characterization of host and bacteria in RUTI caused by E. coli with genetically identical or different strains. This study aimed to investigate the host and bacterial characteristics of E. coli RUTI based on molecular typing.
Patients aged 20 years or above who presented with symptoms of UTI in emergency department or outpatient clinics between August 2009 and December 2010 were enrolled. RUTI was defined as patients had 2 or more infections in 6 months or 3 or more in 12 months during the study period. Host factors (including age, gender, anatomical/functional defect, and immune dysfunction) and bacterial factors (including phylogenicity, virulence genes, and antimicrobial resistance) were included for analysis. There were 41 patients (41%) with 91 episodes of E. coli RUTI with highly related PFGE (HRPFGE) pattern (pattern similarity > 85%) and 58 (59%) patients with 137 episodes of E. coli RUTI with different molecular typing (DMT) pattern, respectively. There was a higher prevalence of phylogenetic group B2 and neuA and usp genes in HRPFGE group if the first episode of RUTI caused by HRPFGE E. coli strains and all episodes of RUTI caused by DMT E. coli strains were included for comparison. The uropathogenic E. coli (UPEC) strains in RUTI were more virulent in female gender, age < 20 years, neither anatomical/ functional defect nor immune dysfunction, and phylogenetic group B2. There were correlations among prior antibiotic therapy within 3 months and subsequent antimicrobial resistance in HRPFGE E. coli RUTI. The use of fluoroquinolones was more likely associated with subsequent antimicrobial resistance in most types of antibiotics.
This study demonstrated that the uropathogens in RUTI were more virulent in genetically highly-related E. coli strains. Higher bacterial virulence in young age group (< 20 years) and patients with neither anatomical/functional defect nor immune dysfunction suggests that virulent UPEC strains are needed for the development of RUTI in healthy populations. Prior antibiotic therapy, especially the fluoroquinolones, within 3 months could induce subsequent antimicrobial resistance in genetically highly-related E. coli RUTI.
大肠杆菌是导致尿路感染（UTI）和复发性尿路感染（RUTI）的主要病原体。很少有研究涉及具有遗传相同或不同菌株的大肠杆菌引起的 RUTI 中宿主和细菌的特征。本研究旨在基于分子分型研究大肠杆菌 RUTI 的宿主和细菌特征。
2009 年 8 月至 2010 年 12 月期间，在急诊科或门诊就诊的出现 UTI 症状的 20 岁或以上患者被纳入研究。RUTI 定义为在研究期间 6 个月内发生 2 次或以上感染或 12 个月内发生 3 次或以上感染。宿主因素（包括年龄、性别、解剖/功能缺陷和免疫功能障碍）和细菌因素（包括系统发育、毒力基因和抗菌药物耐药性）被纳入分析。共有 41 名（41%）患者发生 91 次大肠杆菌 RUTI，其具有高度相关的 PFGE（HRPFGE）模式（模式相似度>85%），58 名（59%）患者发生 137 次大肠杆菌 RUTI，具有不同的分子分型（DMT）模式。如果将 HRPFGE 大肠杆菌菌株引起的 RUTI 首次发作和 DMT 大肠杆菌菌株引起的所有 RUTI 发作均包括在内进行比较，那么 HRPFGE 组中肠杆菌科 B2 和 neuA 和 usp 基因的流行率更高。在女性、年龄<20 岁、无解剖/功能缺陷或免疫功能障碍的 RUTI 患者中，尿路致病性大肠杆菌（UPEC）菌株的毒力更高。在 HRPFGE 大肠杆菌 RUTI 中，在 3 个月内使用抗生素治疗与随后的抗菌药物耐药性之间存在相关性。氟喹诺酮类药物的使用与大多数类型抗生素的随后抗菌药物耐药性更相关。
本研究表明，遗传上高度相关的大肠杆菌菌株中 RUTI 的病原体毒力更强。年轻年龄段（<20 岁）和无解剖/功能缺陷或免疫功能障碍的患者中更高的细菌毒力表明，在健康人群中，需要毒力更强的 UPEC 菌株才能发展为 RUTI。在 3 个月内使用抗生素治疗，尤其是氟喹诺酮类药物，可能会在遗传上高度相关的大肠杆菌 RUTI 中诱导随后的抗菌药物耐药性。
