Intimin type influences the site of human intestinal mucosa colonisation by enterohaemorrhagic Escherichia coli O157 : H7.
Background: Enterohaemorrhagic (EHEC) and enteropathogenic (EPEC) Escherichia coli epithelial cell adhesion is characterised by intimate attachment, and attaching and effacing (A/E) lesion formation. This event is mediated in part by intimin binding to another bacterial protein, Tir (translocated intimin receptor), which is exported by the bacteria and integrated into the host cell plasma membrane. Importantly, EPEC (O127:H6) and EHEC (O157:H7) express antigenically distinct intimin types known as intimin alpha and gamma, respectively. EHEC (O157:H7) colonises human intestinal explants although adhesion is restricted to the follicle associated epithelium of Peyer's patches. This phenotype is also observed with EPEC O127:H6 engineered to express EHEC intimin gamma. Aims: To investigate the influence of intimin on colonisation of human intestine by E coli O157:H7, and intimin types on tissue tropism in humans. Methods: Human intestinal in vitro organ culture with wild type and mutant strains of O157:H7 were employed. Results: Introducing a deletion mutation in the eae gene encoding intimin gamma in EHEC (O157:H7) caused the strain (ICC170) to fail to colonise human intestinal explants. However, colonisation of Peyer's patches and A/E lesion formation were restored with intimin gamma expression from a plasmid (ICC170 (pICC55)). In contrast, complementing the mutation with intimin alpha resulted in a strain (ICC170 (pCVD438)) capable of colonising and producing A/E lesions on both Peyer's patch and other small intestinal explants. Conclusion: Intimin is necessary for human intestinal mucosal colonisation by E coli O157:H7. Intimin type influences the site of colonisation in a Tir type independent mechanism; intimin gamma appears to restrict colonisation to human follicle associated epithelium
|Title:||Intimin type influences the site of human intestinal mucosa colonisation by enterohaemorrhagic Escherichia coli O157 : H7|
|Additional information:||Journal English Article BRITISH MED JOURNAL PUBL GROUP FEB 514BQ LONDON GUT BRITISH MED ASSOC HOUSE, TAVISTOCK SQUARE, LONDON WC1H 9JR, ENGLAND|
|Keywords:||Adhesion, ALPHA, As, attachment, Bacteria, BACTERIAL, Bacterial Protein, Bacterium, BINDING, British, cell, Cell Adhesion, CELL-ADHESION, Child, culture, DELETION, DISTINCT, E, EAE GENE, EFFACING PHENOTYPE, EHEC, English, ENTEROCYTE EFFACEMENT, enterohaemorrhagic, enteropathogenic, EPEC, EPITHELIA, epithelial, epithelial cell, EPITHELIAL- CELLS, Epithelium, Escherichia coli, Escherichia coli O157, ESCHERICHIA-COLI, expression, follicle, formation, gamma, GENE, GNOTOBIOTIC PIGLETS, Gut, HEMORRHAGIC COLITIS, HOST-CELLS, HUMANS, in vitro, In-vitro, intestinal, intestinal mucosa, intestine, intimin, INTIMIN-ALPHA, lesion, Lesions, MECHANISM, MED, membrane, Methods, MUCOSA, Mucosal, Mutant, Mutation, Organ Culture, ORGAN-CULTURE, Other, PATHOGENICITY ISLAND, Peyer's Patches, PEYERS-PATCHES, Phenotype, plasma, Plasma membrane, PLASMA-MEMBRANE, plasmid, PROTEIN, Receptor, Result, SITE, small, Strain, STRAINS, Tir, Tissue, TISSUE-CULTURE CELLS, Tropism, VITRO, WILD-TYPE|
|UCL classification:||UCL > School of Life and Medical Sciences
UCL > School of Life and Medical Sciences > Faculty of Population Health Sciences > Institute of Child Health
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