Cassels F J, Wolf M K
Department of Gastroenterology, Walter Reed Army Institute of Research, Washington, DC 20307-5100, USA.
J Ind Microbiol. 1995 Sep;15(3):214-26. doi: 10.1007/BF01569828.
While Escherichia coli is common as a commensal organism in the distal ileum and colon, the presence of colonization factors (CF) on pathogenic strains of E. coli facilitates attachment of the organism to intestinal receptor molecules in a species- and tissue-specific fashion. After the initial adherence, colonization occurs, and the involvement of additional virulence determinants leads to illness. Enterotoxigenic E. coli (ETEC) is the most extensively studied of the five categories of E. coli that cause diarrheal disease, and has the greatest impact on health worldwide. ETEC can be isolated from domestic animals and humans. The biochemistry, genetics, epidemiology, antigenic characteristics, and cell and receptor binding properties of ETEC have been extensively described. Another major category, enteropathogenic E. coli (EPEC), has virulence mechanisms, primarily effacement and cytoskeletal rearrangement of intestinal brush borders, that are distinct from ETEC. An EPEC CF receptor has been purified and characterized as a sialidated transmembrane glycoprotein complex directly attached to actin, thereby associating CF-binding with host-cell response. Three additional categories of E. coli diarrheal disease, their colonization factors and their host cell receptors, are discussed. It appears that biofilms exist in the intestine in a manner similar to oral bacterial biofilms, and that E. coli is part of these biofilms as both commensals and pathogens.
虽然大肠杆菌作为远端回肠和结肠中的共生生物很常见，但致病性大肠杆菌菌株上存在的定植因子（CF）有助于该生物体以物种和组织特异性方式附着于肠道受体分子。初始黏附后发生定植，其他毒力决定因素的参与会导致疾病。产肠毒素大肠杆菌（ETEC）是导致腹泻病的五类大肠杆菌中研究最广泛的，对全球健康影响最大。ETEC可从家畜和人类中分离出来。ETEC的生物化学、遗传学、流行病学、抗原特性以及细胞和受体结合特性已被广泛描述。另一个主要类别，即肠致病性大肠杆菌（EPEC），其毒力机制主要是肠道刷状缘的缺失和细胞骨架重排，与ETEC不同。一种EPEC CF受体已被纯化并鉴定为直接附着于肌动蛋白的唾液酸化跨膜糖蛋白复合物，从而将CF结合与宿主细胞反应联系起来。还讨论了另外三类大肠杆菌腹泻病、它们的定植因子及其宿主细胞受体。看来生物膜在肠道中的存在方式与口腔细菌生物膜类似，并且大肠杆菌作为共生菌和病原体都是这些生物膜的一部分。
