The role of intimin in the adherence of enterohaemorrhagic Escherichia coli (EHEC) O157: H7 to HEp-2 tissue culture cells and to bovine gut explant tissues.
Intimin, an outer membrane protein encoded by eaeA, is a key determinant for the formation of attaching and effacing (AE) lesions by enterohaemorrhagic Escherichia coli (EHEC). To investigate the role of intimin in adherence, the eaeA gene was insertionally inactivated in three EHEC O157:H7 strains of diverse origin. The absence or presence of intimin did not correlate with the extent of adhesion of mutant or wild-type O157:H7 in tissue culture and neonatal calf gut tissue explant adherence assays. Adherence of the eaeA mutants to HEp-2 cells was diffuse with no evidence of intimate attachment whereas wild-type bacteria formed microcolonies and AE lesions. Intimin-independent adherence to neonatal calf gut explants was demonstrated by eaeA mutants and wild-type strains which adhered in the greatest numbers to colon but least well to rumen tissue. These results confirm that intimin is necessary for intimate attachment and that additional adherence factors are involved in intimin-independent adherence.
Cookson
Adrian L
AL
Department of Bacterial Diseases, Veterinary Laboratories Agency (Weybridge), Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK.
Woodward
Martin J
MJ
D018829:Adhesins, Bacterial / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001422:Bacterial Adhesion; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002417:Cattle; D002460:Cell Line; D046508:Culture Techniques; D004847:Epithelial Cells / Q000382:microbiology; D004927:Escherichia coli Infections / Q000382:microbiology; D019453:Escherichia coli O157 / Q000472:pathogenicity* / Q000502:physiology; D029968:Escherichia coli Proteins; D006801:Humans; D007422:Intestines / Q000382:microbiology*
D018829:Adhesins, Bacterial; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; C073819:eaeA protein, E coli