Changes

Jump to navigation Jump to search
no edit summary
Line 1: Line 1: −
===Colibacillosis===
+
===[[Colibacillosis]]===
   −
* The enteritis caused by colibacillosis is relatively mild although the [[Intestine Diarrhoea - Pathology|diarrhoea]] can be severe.
  −
* Only a few strains of coliform organisms cause disease.
  −
** These are identified by their serotypes.
  −
  −
====Pathogenesis====
  −
  −
* There are three mechanisms by which coliform organisms cause [[Intestine Diarrhoea - Pathology|diarrhoea]].
  −
  −
=====Enterotoxigenic  [[Escherichia coli|''E. Coli'']] (ETEC)=====
  −
  −
* Cause neonatal and post-weaning [[Intestine Diarrhoea - Pathology|diarrhoea]] in ruminants and pigs.
  −
** In calves, ETEC are only seen in animals of 4-5 days, or possibly up to one week, of age.
  −
*** If the animal is older than 1 week, the agent is NOT ETEC.
  −
** Housed lambs may also suffer from ETEC.
  −
*** Animals are usually under 1 week old.
  −
*** Sheep do not suffer as commonly as calves, as they are normally better managed.
  −
** Pigs less than 1 week of age may suffer.
  −
* Bacteria adhere to enterocyte receptors using pili e.g. K87 (Especially in pigs), K88, K99 (especialoly in cattle).
  −
** Toxins produced by the bacteria encourage loss of Cl<sup>-</sup>, Na<sup>+</sup> and water in gut secretions.
  −
*** Causes [[Intestine Diarrhoea - Pathology|diarrhoea]] and dehydration.
  −
*** Death is a result of dehydration and electrolyte loss.
  −
* To be pathogenic, ETECs require 2 qualities not found in non-pathogenic coliform organisms.
  −
** Adherence factors.
  −
** Heat stable toxins.
  −
* Control is by management factors, such as hygiene, good colostral intake and so on.
  −
** There is the potential in the future to breed from pigs that lack adherence antigen sites for ''E.coli''.
  −
  −
=====Enteroinvasive  [[Escherichia coli|''E. Coli'']]=====
  −
  −
* Not common in animals!
  −
* These strains act like shigella or salmonella.
  −
** Penetrate enterocytes, invade lamina propria and spread to lymph nodes and beyond.
  −
* Toxin damages enterocytes, causing:
  −
** Blunting of villi.
  −
** Elongation of crypts.
  −
** Sometimes mucosal ulceration.
  −
  −
=====Enteropathogenic (attaching and effacing) [[Escherichia coli|''E. coli'']]=====
  −
  −
* Penetrate glycocalyx, adhere closely to mucosal cell surface and destroy the microvilli.
  −
* Cause:
  −
** Blunting of villi.
  −
** Crypt hypertrophy.
  −
** Inflammatory cells in the lamina propria.
  −
* The [[Colon - Anatomy & Physiology|colon]] is often more severely affected than the intestine.
  −
  −
* Septicaemic coliform infections may also occur.
  −
** Mainly in first 2 days of life.
  −
*** usually due to insufficient colostrum intake.
  −
** Produce peracute death without diarrhoea.
  −
  −
====Pathology====
  −
  −
=====Gross=====
  −
  −
* Gut loops filled with gas and fluid.
  −
* Gut contents are mucoid.
  −
* Gut wall is flaccid.
  −
* Mild congestion.
  −
  −
=====Histological=====
  −
  −
* Bacteria on epithelial surface.
  −
* Mild inflammation in the lamina propria.
  −
* More severe lesions e.g. villus atrophy are rare.
  −
  −
====Treatment====
  −
  −
* It is pointless to try to kill the organism in this disease.
  −
* Treat the effects of the disease instead.
  −
** Fluid replacement therapy.
  −
*** Produces a quite good and quick recovery, especially in calves.
      
===Enterotoxaemias - Bacterial Diseases===
 
===Enterotoxaemias - Bacterial Diseases===
Line 134: Line 62:  
** Another mouse can be protected from the effect of the toxin with a specific antibody.
 
** Another mouse can be protected from the effect of the toxin with a specific antibody.
 
* An ELISA test is also possible.
 
* An ELISA test is also possible.
** However, an ELISA is often too sensitive as the toxin can be present in the normal sheep gut and the ELISA can pick this up.[[Category:Intestine_-_Inflammatory_Pathology_by_Cause]]
+
** However, an ELISA is often too sensitive as the toxin can be present in the normal sheep gut and the ELISA can pick this up.
 +
 
 +
[[Category:Intestine_-_Inflammatory_Pathology_by_Cause]]
Author, Donkey, Bureaucrats, Administrators
53,803

edits

Navigation menu