358 bytes added ,  10:45, 9 February 2008
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***ST is not immunogenic; it is small, with only 19 amino acids
 
***ST is not immunogenic; it is small, with only 19 amino acids
 
*Enteropathogenic ''E. coli'' (EPEC):
 
*Enteropathogenic ''E. coli'' (EPEC):
 +
**Attching and effacing strains of ''E. coli''
 +
**Attach to small intestinal epithelial cells and cause necrosis of enterocytes and stunting and fusion of villi
 
**Possess ''E. coli'' adherence factor plasmid
 
**Possess ''E. coli'' adherence factor plasmid
 
**An adhesin, intimin is required for attachment to enterocytes
 
**An adhesin, intimin is required for attachment to enterocytes
**Cause attching and effacing lesions in the gut, with necrosis of enterocytes and stunting and fusion of villi
+
**Secrete signalling proteins that activate a tyrosine kinase, causing rearrangement of cytoskeletal proteins and effacement of microvilli
 +
**Intracellular calcium levels increase and production of protein kinase C causes loss of chloride ions and water from the intestinal epithelial cells
 +
**Diarrhoea results
 
*Enteroinvasive ''E. coli'':
 
*Enteroinvasive ''E. coli'':
 
**Cause colisepticaemia in calves during their first week of life; occasionally in lambs, piglets and puppies
 
**Cause colisepticaemia in calves during their first week of life; occasionally in lambs, piglets and puppies
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