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*K99 associated with adhesion in pigs and cattle (these possess certain fimbrae, and are now renamed F antigens)
*K99 associated with adhesion in pigs and cattle (these possess certain fimbrae, and are now renamed F antigens)
*The fimbrae are encoded by plasmids
*The fimbrae are encoded by plasmids
*''E. coli'' may cause diarrhoea via attaching and efacing lesions, where bacteria adhere intimately to the enterocyte, and cause localised effacement of the brush border microvilli
*Enterotoxigenic ''E. coli'':
*Enterotoxigenic ''E. coli'':
**These strains carry a plasmid which encodes an enterotoxin
**These strains carry a plasmid which encodes an enterotoxin
**The gut becomes distended with fluid and a diarrhoea which lasts several days results
**The gut becomes distended with fluid and a diarrhoea which lasts several days results
**LT is antigenic
**LT is antigenic
**Immunity is developed via production of antibody to LT protein and fimbrial antigen
**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 activates guanylate cyclase in enteric epithelial cells, stimulating fluid secretion
*Enteropathogenic ''E. coli'':
**Possess ''E. coli'' adherencefactor plasmid
**Cause attching and effacing lesions in the gut
*Enteroinvasive ''E. coli''
**Dysentry-like strains
**Invade epithelial cells by inducing endocytosis
**Traverse gut wall to lamina propria
*Enterohaemorrhagic ''E. coli'':
**Possibly carried by cattle
**Produce shiga-like toxin, a vero toxin, especially O157:H7
**Attaching and effacing lesions, unrelated to toxin production
**Disseminated intravascular coagulation and thrombus formation
*Enteroaggretative ''E. coli'':
*Oedema disease