Difference between revisions of "Campylobacter jejuni"

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''Campylobacter jejuni belongs to the genus [[Campylobacter species- Overview|''Campylobacter'']].
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''Campylobacter jejuni belongs to the genus [[Campylobacter species- Overview|''Campylobacter'']]. ''C.jejuni'' is an important enteropathogen of man and a number of animal species. It is the largest cause of food-poisoning in the UK and is therefore a public health issue.
 
It is widespread on farms and is hyperendemic. It can be carried as commensals in the intestines of cattle, sheep, dogs, wild birds and especially chickens.
 
It is widespread on farms and is hyperendemic. It can be carried as commensals in the intestines of cattle, sheep, dogs, wild birds and especially chickens.
 
Farm animals are regularly exposed via the faecal-oral route. Maternal antibody protects the animal while the active immunity develops. Animals with little exposure are very susceptible, e.g. humans and pets.
 
Farm animals are regularly exposed via the faecal-oral route. Maternal antibody protects the animal while the active immunity develops. Animals with little exposure are very susceptible, e.g. humans and pets.
Most chicken carcasses are contaminated, leading to food poisoning and enterocolitis in people from uncooked meat.  
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Most chicken carcasses are contaminated, leading to food poisoning and enterocolitis in people from uncooked meat. If frozen chicken is inadequately thawed, bacteria may remain viable in the abdominal cavity
  
Pathogenesis of ''C.jejuni'' involves the colonisation, attachment and invasion of colonic enterocytes and toxin production.  
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==Pathogenesis==
[[Category:Enteritis, Bacterial|Enteritis]] and diarrhoea in susceptible dogs; treatment with enrofloxacin
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The pathogenesis of ''C.jejuni'' involves the colonisation, attachment and invasion of colonic enterocytes and toxin production.  
*Causes abortion in ewes
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It causes colitis, characterised by; Necrosis of absorptive epithelial cells; Erosion of the mucosa; Crypt abscesses; The infiltration of inflammatory cells into the mucosa and the presence of primarily [[Neutrophils|neutrophils]].
*Usually asymptomatic infections in chickens and turkeys, but occasional outbreaks of avian hepatitis occur with decreased egg production, loss of condition, haemorrhage and necrosis of liver; phase contrast microscopy demonstrates curved rods in bile; in-feed dihydrostreptomycin sulphate in outbreak
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The bacteria's functional flagella are important as virulence factors. Non-flagellate [[Campylobacter species- Overview|campylobacter]] do not colonise in vivo, and are less invasive.
*Implicated in [[Calf Diarrhoea, Undifferentiated Neonatal|undifferentiated neonatal calf diarrhoea]], a mixed viral enteritis in calves[[Category:Campylobacter_species]][[Category:Dog]][[Category:Cattle]][[Category:Sheep]]
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It causes enteritis and diarrhoea in susceptible dogs and causes abortion in ewes.
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It usually causes asymptomatic infections in chickens and turkeys, but occasional outbreaks of avian [[ Hepatitis, Acute|hepatitis]] occur.
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It is implicated in [[Calf Diarrhoea, Undifferentiated Neonatal|undifferentiated neonatal calf diarrhoea]], a mixed viral enteritis in calves.
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''C.jejuni'' are diagnosed by laboratory diagnosis.
  
* An important enteropathogen of man and a number of animal species.
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[[Category:Campylobacter_species]][[Category:Dog]][[Category:Cattle]][[Category:Sheep]]
* The largest cause of food-poisoning in the UK.
 
** Is therefore a public health issue.
 
* Very widely distributed on the farm- carried in the intestinal tract of:
 
** Cattle
 
** Sheep
 
** Dogs
 
** Chickens
 
** Wild birds
 
* Widespread distribution on the farm means that it is hyperendemic.
 
** All animals are regularly exposed to it by the faecal oral route.
 
** Passive (colostral) protection is helpful while active immunity develops.
 
* There is no regular exposure in the hygienic environment of the human or pet dog.
 
** These animals are much more susceptible to infection.
 
* The intestinal contents of the broiler chicken may be spread around the abdominal cavity at slaughter.
 
** Most poultry is moderately or heavily contaminated.
 
*** If frozen chicken is inadequately thawed, bacteria may remain viable in the abdominal cavity.
 
*** Bacteria may be ingested by humans handling the raw meat.
 
  
====Pathogenesis====
 
  
* Bacteria colonise the gut, attach to and invade the mucosa, and produce toxin.
 
* Causes colitis, characterised by:
 
** Necrosis of absorptive epithelial cells
 
** Erosion of the mucosa
 
** Crypt abscesses
 
** Infiltration of inflammatory cells into the mucosa.
 
*** Primarily [[Neutrophils|neutrophils]].
 
* Functional flagella are important as virulence factors.
 
** Non-flagellate campylobacter do not colonise in vivo, and are less invasive in vitro.
 
* Diagnosed by laboratory diagnosis.
 
 
 
Campylobacter fetus or jejuni In ewes, causes abortion storms. Transmission is oral from faeces or aborted material and leads to late abortion, premature and weak lambs. See areas of focal hepatic necrosis in foetus.
 
  
  

Revision as of 11:23, 14 July 2010



Also known as: C.jejuni

Campylobacter jejuni belongs to the genus Campylobacter. C.jejuni is an important enteropathogen of man and a number of animal species. It is the largest cause of food-poisoning in the UK and is therefore a public health issue. It is widespread on farms and is hyperendemic. It can be carried as commensals in the intestines of cattle, sheep, dogs, wild birds and especially chickens. Farm animals are regularly exposed via the faecal-oral route. Maternal antibody protects the animal while the active immunity develops. Animals with little exposure are very susceptible, e.g. humans and pets. Most chicken carcasses are contaminated, leading to food poisoning and enterocolitis in people from uncooked meat. If frozen chicken is inadequately thawed, bacteria may remain viable in the abdominal cavity

Pathogenesis

The pathogenesis of C.jejuni involves the colonisation, attachment and invasion of colonic enterocytes and toxin production. 

It causes colitis, characterised by; Necrosis of absorptive epithelial cells; Erosion of the mucosa; Crypt abscesses; The infiltration of inflammatory cells into the mucosa and the presence of primarily neutrophils. The bacteria's functional flagella are important as virulence factors. Non-flagellate campylobacter do not colonise in vivo, and are less invasive. It causes enteritis and diarrhoea in susceptible dogs and causes abortion in ewes. It usually causes asymptomatic infections in chickens and turkeys, but occasional outbreaks of avian hepatitis occur.

It is implicated in undifferentiated neonatal calf diarrhoea, a mixed viral enteritis in calves.

C.jejuni are diagnosed by laboratory diagnosis.