BACKGROUND Adherent invasive Escherichia coli (AIEC) are implicated in the pathogenesis of inflammatory bowel diseases (IBD) particularly Crohn's disease (CD). The aim of this study is to isolate, identify, genotype, and characterize the virulence factors and the clinical significance of AIEC strains. METHODS Ileal and colonic biopsies from 24 active CD patients and 15 healthy controls (HC) were collected. E. coli strains were identified by standard biochemical tests and confirmed by MALDI-TOF (bioMerieux, France) system. The AIEC phenotypes were determined by the adhesion, invasion, and survival within macrophages assays. The genetic virulence factors and genotyping characteristics were determined by PCR and PFGE respectively. The abundance and the antibiogram profile of E. coli strains was determined by qPCR and VITEK®2 (bioMerieux, France) automated system respectively. RESULTS E. coli strains from 17 CD patients and 14 HC were isolated, 10 (59%) and 7 (50%) of them were identified as AIEC strains, respectively. We found that chuA and ratA genes were the most significant genetic markers associated with AIEC compared to non-AIEC strains isolated from CD patients and HC p = 0.0119, 0.0094 respectively. The majority of E. coli strains obtained from CD patients showed antibiotic resistance (71%) compared to HC (29%) against at least one antibiotic. The AIEC-like strains were more resistant to antibiotics compared to non-AIEC-like strains (53%) and (21%) respectively. CONCLUSIONS We have determined significant differences between AIEC strains and non-AIEC strains in terms of the prevalence of chuA and ratA virulence genes and the antibiotic resistance profiles. In addition, AIEC strains isolated from CD patients were found to be more resistant to penicillin/beta lactam and aminoglycoside antibiotics than AIEC strains isolated from HC 80%, 14% respectively.

中文翻译：

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从克罗恩氏病患者中分离出来的粘附侵袭性大肠杆菌（AIEC）菌株的毒力决定因素和遗传多样性。

背景技术粘附性侵袭性大肠杆菌（AIEC）与炎性肠病（IBD）特别是克罗恩氏病（CD）的发病有关。这项研究的目的是分离，鉴定，基因分型和表征毒力因子以及AIEC菌株的临床意义。方法收集24例活动CD患者和15例健康对照（HC）的回肠和结肠活检。大肠杆菌菌株通过标准生化测试鉴定，并通过MALDI-TOF（法国bioMerieux）系统确认。AIEC表型由巨噬细胞测定法中的粘附，侵袭和存活来确定。通过PCR和PFGE分别确定遗传毒力因子和基因分型特征。大肠杆菌菌株的丰度和抗菌素谱通过qPCR和VITEK®2（bioMerieux，法国）分别为自动化系统。结果共分离出17例CD患者和14例HC患者的大肠杆菌，其中10例（59％）和7例（50％）被鉴定为AIEC菌株。我们发现chuA和ratA基因是与AIEC相关的最重要的遗传标记，与分别从CD患者和HC p = 0.0119，0.0094分离出的非AIEC菌株相比。从CD患者获得的大多数大肠杆菌菌株显示出对至少一种抗生素的抗药性（71％），而HC（29％）。与非AIEC样菌株相比（53％）和（21％），AIEC样菌株对抗生素的耐药性更高。结论我们已经在chuA和ratA毒力基因的流行率和抗生素耐药性方面确定了AIEC菌株与非AIEC菌株之间的显着差异。此外，