Human intestinal tissue tropism in Escherichia coli O157: H7 -: initial colonization of terminal ileum and Peyer's patches and minimal colonic adhesion ex vivo
Human intestinal tissue tropism in Escherichia coli O157: H7 -: initial colonization of terminal ileum and Peyer's patches and minimal colonic adhesion ex vivo
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DOI：
10.1099/mic.0.2006/003178-0
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发表时间：
2007-03-01
期刊：
影响因子：
2.8
通讯作者：
Phillips, Alan D.
中科院分区：
文献类型：
--
作者：
Chong, Yuwen;Fitzhenry, Robert;Phillips, Alan D.
肠出血性大肠杆菌（Enterohemorrhagic Escherichia coli，EHEC）是引起人类肠道和肾脏疾病的重要致病菌，O 157：H7菌株的研究表明，EHEC只在回肠末端派伊尔集合淋巴结的滤泡相关上皮细胞（FAE）上生长，而在小肠和大肠中均无定植。本研究确定了一系列滋贺毒素（Stx）阴性EHEC菌株的嗜性，并使用人体外肠器官培养（IVOC）寻找可能诱导结肠定植的因素。在两种菌株中证实了FAE限制性定植;另外四种菌株定植于回肠绒毛表面，并观察到与近端小肠FAE的粘附。所有菌株均表现出对近端小肠非FAE区域和横结肠的最小粘附。使用三种O 157：H7菌株、一种O26：H11菌株和一种O 103：H2菌株以及从盲肠到直肠的组织进行的广泛大肠IVOC研究发现，113种IVOC中仅4种（3.5%）形成了定植和附着/消失性病变。结肠粘连没有通过改变IVOC技术或环境而增强。共孵育O 157：H7感染的回肠FAE与结肠样品增强结肠定植，产生一种新的，非亲密的粘附表型。因此，在定植的初始阶段，Stx阴性EHEC优先感染离体末端回肠区域的FAE和绒毛;结肠定植很少被观察到作为初始事件，但可能代表感染的后续阶段。
Enterohaemorrhagic Escherichia coli (EHEC) are an important cause of diarrhoeal and renal disease in man. Studies of a single prototypic O157:H7 strain have shown tropism for follicle-associated epithelium (FAE) of distal ileal Peyer's patches without colonization of either small or large intestine. This study determined tropism in a range of Shiga toxin (Stx)-negative EHEC strains and looked for factors that might induce colonic colonization using human in vitro intestinal organ culture (IVOC). An FAE-restricted colonization was confirmed in two strains; four strains additionally colonized ileal villous surfaces, and adhesion to proximal small intestinal FAE was observed. All strains showed minimal adhesion to non-FAE regions of proximal small intestinal and to the transverse colon. Extensive large-bowel IVOC studies using three O157 : H7 strains, an O26:H11 and an O103:H2 strain, and tissue from caecum to rectum found colonization and attaching/effacing lesion formation in only 4 of 113 (3.5%) IVOCs. Colonic adhesion was not enhanced by altering the IVOC technique or environment. Co-incubation of O157:H7-infected ileal FAE with colonic samples enhanced colonic colonization, producing a novel, non-intimate adhesive phenotype. Thus, in the initial stages of colonization Stx-negative EHEC preferentially infect FAE and villi of the terminal ileal region ex vivo; colonic colonization is infrequently observed as an initial event but may represent a subsequent stage of infection.