Intimin, the product of the eaeA gene in enterohemorrhagic Escherichia coli O157:H7 (EHEC), is required for intimate adherence of these organisms to tissue culture cells and formation of the attaching and effacing lesion in the gnotobiotic pig. Because of the importance of intimin in the pathogenesis of EHEC O157:H7 infection in this animal model, we began a structure-function analysis of EaeA....

Intimin facilitates intestinal colonization by enterohemorrhagic Escherichia coli O157:H7; however, the importance of intimin binding to its translocated receptor (Tir) as opposed to cellular coreceptors is unknown. The intimin-Tir interaction is needed for optimal actin assembly under adherent bacteria in vitro, a process which requires the Tir-cytoskeleton coupling protein (TccP/EspF(U)) in E...

Enteropathogenic Escherichia coli (EPEC) is a known causative agent of diarrhea in children. In the process of colonization of the small intestine, EPEC synthesizes two types of adhesins, the bundle-forming pilus (BFP) and intimin. The BFP pilus is an adhesin associated with the initial stages of adherence of EPEC to epithelial cells, while the outer membrane protein intimin carries out the int...

In a previous study, enterohemorrhagic Escherichia coli (EHEC) O157:H7 with a deletion and insertion in the eaeA gene encoding intimin was used to establish that intimin is required for the organism to attach to and efface microvilli in the piglet intestine (M. S. Donnenberg, S. Tzipori, M. L. McKee, A. D. O'Brien, J. Alroy, and J. B. Kaper, J. Clin. Invest. 92:1418-1424, 1993). However, in the...

When 3,972 ground beef enrichments with 6 confirmed to contain a non-O157 Shiga toxin-producing intimin-positive Escherichia coli isolate were tested for Shiga toxin, intimin, and O group (O26, O45, O103, O111, O121, and O145) genes, 183 potential positives and only 2 of the 6 confirmed positives were identified.

Invasin and intimin are major virulence factors of enteropathogenic Yersiniae and Escherichia coli, mediating invasion into and intimate adherence to host cells, respectively. Several studies have hinted that extracellular portion of these homologous proteins might be exported via an autotransport mechanism, but rigorous experimental proof has been lacking. Here, we present a topology model for...

Upon intestinal colonization, enterohemorrhagic Escherichia coli (EHEC) induces epithelial cells to generate actin "pedestals" beneath bound bacteria, lesions that promote colonization. To induce pedestals, EHEC utilizes a type III secretion system to translocate into the mammalian cell bacterial effectors such as translocated intimin receptor (Tir), which localizes in the mammalian cell membra...

Intimin-conjugated fluorescent beads bind to spleen CD4 T cells and Peyer's patch, mesenteric lymph node, and cecal follicle lymphocytes, with less binding to lamina propria T cells and intraepithelial lymphocytes. Intimin costimulates proliferation of spleen CD4 T cells and cells from organized lymphoid tissues but does not costimulate cells from the lamina propria of normal or inflamed colon.

Enteropathogenic Escherichia coli (EPEC), an important paediatric diarrhoeal pathogen, employs multiple adhesins to colonize the small bowel and produces characteristic 'attaching and effacing' (A/E) lesions on small intestinal enterocytes. EPEC adhesins that have been associated with A/E adhesion and intestinal colonization include bundle-forming pili (BFP), EspA filaments and intimin. BFP are...

Escherichia coli O157:H7 is an important food-borne pathogen and cause of hemorrhagic colitis and hemolytic uremic syndrome in humans. Cattle are an important reservoir of E. coli O157:H7, in which the organism colonizes the intestinal tract and is shed in the feces. Vaccination of cattle has significant potential as a pre-harvest intervention strategy for E. coli O157:H7; however, basic inform...