Dupont Aline, Sommer Felix, Zhang Kaiyi, Repnik Urska, Basic Marijana, Bleich André, Kühnel Mark, Bäckhed Fredrik, Litvak Yael, Fulde Marcus, Rosenshine Ilan, Hornef Mathias W
Institute for Medical Microbiology, RWTH Aachen University Hospital, Aachen, Germany.
Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany.
PLoS Pathog. 2016 May 9;12(5):e1005616. doi: 10.1371/journal.ppat.1005616. eCollection 2016 May.
Enteropathogenic Escherichia coli (EPEC) represents a major causative agent of infant diarrhea associated with significant morbidity and mortality in developing countries. Although studied extensively in vitro, the investigation of the host-pathogen interaction in vivo has been hampered by the lack of a suitable small animal model. Using RT-PCR and global transcriptome analysis, high throughput 16S rDNA sequencing as well as immunofluorescence and electron microscopy, we characterize the EPEC-host interaction following oral challenge of newborn mice. Spontaneous colonization of the small intestine and colon of neonate mice that lasted until weaning was observed. Intimate attachment to the epithelial plasma membrane and microcolony formation were visualized only in the presence of a functional bundle forming pili (BFP) and type III secretion system (T3SS). Similarly, a T3SS-dependent EPEC-induced innate immune response, mediated via MyD88, TLR5 and TLR9 led to the induction of a distinct set of genes in infected intestinal epithelial cells. Infection-induced alterations of the microbiota composition remained restricted to the postnatal period. Although EPEC colonized the adult intestine in the absence of a competing microbiota, no microcolonies were observed at the small intestinal epithelium. Here, we introduce the first suitable mouse infection model and describe an age-dependent, virulence factor-dependent attachment of EPEC to enterocytes in vivo.
肠致病性大肠杆菌(EPEC)是发展中国家婴儿腹泻的主要病原体,与显著的发病率和死亡率相关。尽管在体外进行了广泛研究,但由于缺乏合适的小动物模型,体内宿主-病原体相互作用的研究受到了阻碍。我们使用逆转录聚合酶链反应(RT-PCR)、全局转录组分析、高通量16S核糖体DNA测序以及免疫荧光和电子显微镜,对新生小鼠口服攻击后EPEC与宿主的相互作用进行了表征。观察到新生小鼠的小肠和结肠自发定植,这种定植持续到断奶。只有在功能性束状菌毛(BFP)和III型分泌系统(T3SS)存在的情况下,才能观察到与上皮细胞质膜的紧密附着和微菌落形成。同样,通过MyD88、TLR5和TLR9介导的T3SS依赖性EPEC诱导的先天免疫反应,导致受感染的肠上皮细胞中一组独特基因的诱导。感染引起的微生物群组成变化仅限于出生后时期。尽管在没有竞争性微生物群的情况下EPEC定殖于成年肠道,但在小肠上皮未观察到微菌落。在这里,我们介绍了第一个合适的小鼠感染模型,并描述了EPEC在体内对肠上皮细胞的年龄依赖性、毒力因子依赖性附着。