Difference between revisions of "Category:Histotoxic Clostridia"

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===Clostridium novyi===
+
===[[Clostridium novyi]]===
 
 
*Infectious necrotic hepatitis/black disease:
 
**Acute disease of sheep, occasionally cattle
 
**Hepatic necrosis caused by exotoxins of ''C. novyi'' type B in liver damaged by ''Fasciola hepatica''
 
**Rapid death
 
**Dark discoloration of skin caused by subcutaneous venous congestion
 
**Fluorescent antibody test diagnostic
 
* Causes [[Necrosis - Pathology#Gas Gangrene|gas gangrene]] and [[Muscles Inflammatory - Pathology#Gas gangrene|myositis]].
 
*May be involved in [[Bacterial skin infections - Pathology#Systemic bacterial infections|cutaneous lesions]]
 
*Causes big head in rams - oedema of subcutaneous tissues of the head, neck and cranial thorax; necrotising lethal alpha toxin
 
  
  

Revision as of 10:55, 12 May 2010

  • Exotoxins cause local tissue necrosis and systemic effects which can be fatal - toxaemia
  • C. chauvei and C. septicum present in muscle as latent spores which can germinate to cause infection
  • C. novyi type B and C. haemolyticum have latent spores in the liver
  • When inoculated into wounds, cause malignant oedema and gas gangrene
  • Endospores persist in the soil
  • Most ingested spores excreted in faeces, but some become dormant in tissues
  • Tissue injury leads to reduced oxygen tensions allowing germination and replication of bacteria
  • Exotoxins cause local necrosis
  • Activated spores in the liver and muscles cause endogenous infections including blackleg, infectious necrotic hepatitis and bacillary haemoglobinuria
  • Inoculation of wounds causes exogenous infections including malignant oedema and gas gangrene


Clostridium chauvei

Clostridium septicum

Clostridium novyi

Clostridium perfringens type A

  • Gas gangrene and myositis
    • Extensive bacterial invasion of damaged muscle
    • Gas production causing subcutaneous crepitus
    • Similar manifestations as malignant oedema


Clostridium haemolyticum

  • Causes bacillary haemoglobinuria in cattle, occasionally sheep
  • Endogenous infection - endospores dormant in liver
  • Fluke migration allows germination
  • Beta toxin causes intravascular haemolysis and hepatic necrosis
  • Haemoglobinuria due to destruction of red blood cells


Clostridium sordelli


Treatment of histotoxic infections

  • Early penicillin
  • Vaccination with bacterin or toxoid at 3 months and booster after 3 weeks, then annually

Pages in category "Histotoxic Clostridia"

The following 6 pages are in this category, out of 6 total.