Role of intimin and bundle-forming pili in enteropathogenic Escherichia coli adhesion to pediatric intestinal tissue in vitro
Role of intimin and bundle-forming pili in enteropathogenic Escherichia coli adhesion to pediatric intestinal tissue in vitro
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DOI：
10.1128/iai.66.4.1570-1578.1998
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发表时间：
1998-04-01
影响因子：
3.1
通讯作者：
Phillips, AD
中科院分区：
文献类型：
--
作者：
Hicks, S;Frankel, G;Phillips, AD
附着和消除(A/E)病变的形成是肠源性大肠埃希菌(EPEC)发病机制的核心，体外人上皮细胞株的实验表明，最初结合的是毒力性质粒编码的束形成丸(BFP)，亲密附着的是内膜，A/E病变的形成涉及到毒力。本研究在体外器官培养中研究了BFP和内膜蛋白在EPEC与儿童小肠活检组织相互作用中的作用。用E2348/69(野生型EPEC O127：H6临床分离株)和E2348/69的衍生物进行器官培养感染(2~8h)，其中包括CVD206(EAE缺失)、CVD206(PCVD438)(EAE互补的CVD206)、CVD206(pCVD438/01)(表达内膜蛋白，由于单一氨基酸替换而无功能)、JPN15(自发的EPEC黏附因子毒力质粒治愈的E2348/69)和31-6-1(1)(E2348/69在毒力质粒编码的bfpA基因中插入了TnPhoA的插入突变)。扫描和透射电子显微镜显示，8h后E2348/69和CVD206(PCVD438)(均为Int(+)BFP+)在所有标本上黏附，导致A/E病变周围微绒毛延长。JPN15和31-6-1(1)(Int(+)BFP-)黏附并引起A/E损害，尽管细菌黏附在“平面”二维组中，CVD206和CVD206(pCVD438/01)(Int(-)BFP+)不附着于任何样本，也没有观察到病理组织变化，因此，在人类肠道器官培养中，BFP似乎不参与EPEC非亲密黏附的初始阶段，但通过细菌与细菌的相互作用参与形成复杂的三维菌落。内膜似乎在建立儿科小肠组织上的EPEC定植中起着重要作用。
Attaching and effacing (A/E) lesion formation is central to enteropathogenic Escherichia coli (EPEC) pathogenesis, In vitro experiments with human epithelial cell lines have implicated virulence plasmid-encoded bundle-forming pill (BFP) in initial binding and intimin in intimate attachment and A/E lesion formation. This study investigated the role of BFP and intimin in EPEC interactions with pediatric small intestinal biopsy tissue in in vitro organ culture. Organ culture infections (2 to 8 h) were performed with E2348/69 (a wild-type EPEC O127:H6 clinical isolate) and E2348/69 derivatives including CVD206 (eae deficient), CVD206(pCVD438) (eae-complemented CVD206), CVD206(pCVD438/01) (expressing intimin, which is nonfunctional due to a single amino acid substitution), JPN15 (spontaneous EPEC adherence factor virulence plasmid-cured E2348/69), and 31-6-1(1) (E2348/69 with a TnphoA insertion inactivation mutation in the virulence plasmid-encoded bfpA gene). Scanning and transmission electron microscopy revealed that after 8 h E2348/69 and CVD206 (pCVD438) (both Int(+) BFP+) adhered to all specimens, causing A/E lesions with surrounding microvillous elongation. JPN15 and 31-6-1(1) (both Int(+) BFP-) adhered and caused A/E lesions although bacteria adhered in "flat," two-dimensional groups, CVD206 and CVD206(pCVD438/01) (both Int(-) BFP+) did not adhere to any sample, and no pathological tissue changes were seen, Thus, in human intestinal organ culture, BFP do not appear to be involved in the initial stages of EPEC nonintimate adhesion but are implicated in the formation of complex, three-dimensional colonies via bacterium-bacterium interactions. Intimin appears to play an essential role in establishing colonization of EPEC on pediatric small intestinal tissue.