Difference between revisions of "Escherichia coli"
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*Grow on MacConkey agar (in presence of bile salts) | *Grow on MacConkey agar (in presence of bile salts) | ||
*Reduce nitrates to nitrits and ferment glucose to produce acid and gas | *Reduce nitrates to nitrits and ferment glucose to produce acid and gas | ||
| − | *Possess a lipolysaccharide O antigen, a flagellate H antigen, polysaccharide K antigens and fimbrial F antigens | + | *Possess a lipolysaccharide (O) antigen, a flagellate (H) antigen, polysaccharide capsule (K) antigens and fimbrial (F) antigens |
*Epidemiological typing of ''E. coli'' uses antigen combinations, eg. O125:K12:H42 | *Epidemiological typing of ''E. coli'' uses antigen combinations, eg. O125:K12:H42 | ||
===Extra-intestinal infection=== | ===Extra-intestinal infection=== | ||
| + | |||
| + | *Soft tissue infections in adult animals | ||
| + | *Most common organism infecting urinary tract | ||
| + | *Causes pyometra in the dog and cat and pyelonephritis | ||
| + | *Acute mastitis in lactating animals | ||
| + | *Pathogenesis: | ||
| + | **Produces an alpha-haemolysin which may be cytotoxic | ||
| + | **Iron aquisition system | ||
| + | **K antigens prevent phagocytosis or mimic host antigens and resist complement | ||
| + | **Fimbriae permit adhesion to mucosal surfaces | ||
Revision as of 15:40, 21 December 2007
- Enterotoxigenic E.coli contributes to undifferentiated neonatal calf diarrhoea, a mixed viral enteritis in calves.
- Colibacillosis.
- Histiocytic ulcerative colitis in the dog and cat.
- Causes secretory diarrhoea
- Causes peritonitis in dogs and peritonitis in pigs
- In osteomyelitis
- In neonatal polyarthritis of calves
- In arthritis of horses
Eschericia coli (E. coli) overview
- Member of Enterobacteriacae family of Gram-negative bacilli
- Facultative anaerobe
- One of predominant bacterial species in colonic flora
- Abundant in the environment
- Found in many non-specific, endogenous infections, eg. wound infections and upper respiratory tract infections and septicaemia
- Also and enteropathogen
E. coli characteristics
- Oxidase negative (do not possess cytochrome C oxidase)
- Grow on MacConkey agar (in presence of bile salts)
- Reduce nitrates to nitrits and ferment glucose to produce acid and gas
- Possess a lipolysaccharide (O) antigen, a flagellate (H) antigen, polysaccharide capsule (K) antigens and fimbrial (F) antigens
- Epidemiological typing of E. coli uses antigen combinations, eg. O125:K12:H42
Extra-intestinal infection
- Soft tissue infections in adult animals
- Most common organism infecting urinary tract
- Causes pyometra in the dog and cat and pyelonephritis
- Acute mastitis in lactating animals
- Pathogenesis:
- Produces an alpha-haemolysin which may be cytotoxic
- Iron aquisition system
- K antigens prevent phagocytosis or mimic host antigens and resist complement
- Fimbriae permit adhesion to mucosal surfaces