Changes

*Some strains possess fimbrae which attach the bacteria to the small intestinal epithelium of particular animal species

*Some strains possess fimbrae which attach the bacteria to the small intestinal epithelium of particular animal species

*''E. coli'' may cause diarrhoea via attaching and effacing lesions, where bacteria adhere intimately to the enterocyte, and cause localised effacement of the brush border microvilli; the epithelial erosion causes [[General Pathology - Haemorrhage|Dysentery|dysentery]]

*''E. coli'' may cause diarrhoea via attaching and effacing lesions, where bacteria adhere intimately to the enterocyte, and cause localised effacement of the brush border microvilli; the epithelial erosion causes [[General Pathology - Haemorrhage|Dysentery|dysentery]]

*'''Enterotoxigenic ''E. coli'' (ETEC)''':

*'''Enterotoxigenic ''E. coli'' (ETEC)''':

**General:

**General:

***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

*Enteropathogenic ''E. coli'' (EPEC):

 

**Attching and effacing strains of ''E. coli''

 

*'''Enteropathogenic ''E. coli'' (EPEC)''':

**Attaching and effacing strains of ''E. coli''

**Attach to small intestinal epithelial cells and cause necrosis of enterocytes and stunting and fusion of villi

**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

**Intracellular calcium levels increase and production of protein kinase C causes loss of chloride ions and water from the intestinal epithelial cells

**Intracellular calcium levels increase and production of protein kinase C causes loss of chloride ions and water from the intestinal epithelial cells

**Diarrhoea results

**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

**Infection via ingestion or umbilicus; inadequate colostrum increases susceptibility

**Infection via ingestion or umbilicus; inadequate colostrum increases susceptibility

**Abscesses, pneumonia in long term

**Abscesses, pneumonia in long term

**Death occurs in absense of treatment

**Death occurs in absense of treatment

*Enterohaemorrhagic ''E. coli'':

 

 

*'''Enterohaemorrhagic ''E. coli''''':

**Possibly carried by cattle

**Possibly carried by cattle

**Produce shiga-like toxin, a vero toxin

**Produce shiga-like toxin, a vero toxin

**Plasmid-coded fimbriae important for virulence

**Plasmid-coded fimbriae important for virulence

**Intimin produced allowing intimate attchment to intestinal epithelial cells

**Intimin produced allowing intimate attachment to intestinal epithelial cells

**Strains do not product LT or ST and are not enteroinvasive

**Strains do not product LT or ST and are not enteroinvasive

**Attaching and effacing lesions, unrelated to toxin production

**Attaching and effacing lesions, unrelated to toxin production

**Disseminated intravascular coagulation and thrombus formation  

**Disseminated intravascular coagulation and thrombus formation  

**''E. coli'' O157:H7 causes haemorrhagic collitis-haemolytic uraemic syndrome in humans

**''E. coli'' O157:H7 causes haemorrhagic collitis-haemolytic uraemic syndrome in humans

*Cytotoxin necrotising factor-producing ''E. coli''

 

 

*'''Cytotoxin necrotising factor-producing ''E. coli'''''

**Infrequently cause diarrhoea in calves, pigs and humans

**Infrequently cause diarrhoea in calves, pigs and humans

**Important virulence factors include toxin and fimbriae

**Important virulence factors include toxin and fimbriae