Line 103: |
Line 103: |
| ***This causes irreversible activation of adenylate cyclase in target cells | | ***This causes irreversible activation of adenylate cyclase in target cells |
| ***This raises the cAMP level and causes hypersecretion of water and chloride ions into the lumen of the small intestine and inhibits reabsorption of sodium | | ***This raises the cAMP level and causes hypersecretion of water and chloride ions into the lumen of the small intestine and inhibits reabsorption of sodium |
| + | ***ST activates guanylate cyclase in enteric epithelial cells, stimulating fluid secretion |
| **Clinical signs: | | **Clinical signs: |
| ***The gut becomes distended with fluid and a [[Intestines - diarrhoea#Secretory Diarrhoeas|secretory diarrhoea]] which lasts several days results | | ***The gut becomes distended with fluid and a [[Intestines - diarrhoea#Secretory Diarrhoeas|secretory diarrhoea]] which lasts several days results |
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Line 112: |
| ***Parenteral vaccination of pigs and cattle protects offspring from scours via antibody production in the colostrum (passive immunity) | | ***Parenteral vaccination of pigs and cattle protects offspring from scours via antibody production in the colostrum (passive immunity) |
| ***ST is not immunogenic; it is small, with only 19 amino acids | | ***ST is not immunogenic; it is small, with only 19 amino acids |
− | ***ST activates guanylate cyclase in enteric epithelial cells, stimulating fluid secretion
| |
| *Enteropathogenic ''E. coli'' (EPEC): | | *Enteropathogenic ''E. coli'' (EPEC): |
| **Possess ''E. coli'' adherence factor plasmid | | **Possess ''E. coli'' adherence factor plasmid |
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| **Cause attching and effacing lesions in the gut, with necrosis of enterocytes and stunting and fusion of villi | | **Cause attching and effacing lesions in the gut, with necrosis of enterocytes and stunting and fusion of villi |
| *Enteroinvasive ''E. coli'': | | *Enteroinvasive ''E. coli'': |
| + | **Bacteraemia and septicaemia |
| **Dysentry-like strains | | **Dysentry-like strains |
| **Invade epithelial cells by inducing endocytosis | | **Invade epithelial cells by inducing endocytosis |