Difference between revisions of "Erysipelothrix rhusiopathiae"

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<big><center>[[Infectious agents and parasites|'''BACK TO INFECTIOUS AGENTS AND PARASITES''']]</center></big>
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===Overview===
<big><center>[[Bacteria|'''BACK TO BACTERIA''']]</center></big>
 
  
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*Causes erysipelas in pigs and turkeys worldwide
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*[[Infectious Arthritis#In Pigs|Arthritis and discospondylitis in pigs]] as well as [[Bacterial skin infections - Pathology#Systemic bacterial infections|cutaneous lesions]]
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*Occasionally causes [[Infectious Arthritis#In Sheep|arthritis in sheep]] and disease in other animals
 +
*Causes erysipeloid, a localised cellulitis in humans
 +
*Found in porcine tonsils - 50% of pigs are thought to be carriers
 +
*Bacteria excreted in faeces and oronasal secretions
 +
*Survive in soil for less than 35 days
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*Present on fish
  
*Causes [[Joints - inflammatory#In Sheep|arthritis in sheep]] and [[Joints - inflammatory#In Pigs|arthritis and discospondylitis in pigs]]
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*May be involved in [[Bacterial skin infections#Systemic bacterial infections|cutaneous lesions]]
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===Characteristics===
 +
 
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*Gram-positive, small rod (smooth form) or filamentous (rough form)
 +
*Facultative anaerobe
 +
*Non-motile
 +
*Catalase negative, oxidase negative, coagulase positive
 +
*Grow on nutrient agar; growth enhanced by addition of blood or serum
 +
*Small colonies with incomplete haemolysis in 48 hours
 +
*Hydrogen sulphide formed as black central line in TSI agar
 +
*Growth over wide rangs of temperatures and pH
 +
 
 +
 
 +
===Identification and diagnosis===
 +
 
 +
*Isolates from acute infections produce smooth colonies; 1.5mm diamteter, convex and circular with even edges
 +
*Isolates from chronic infections produce rough colonies; larger, flat and opaque colonieswith irregular edges
 +
*Biochemical tests
 +
*Serotypying according to a heat-stable peptidoglycan extracted from the cell wall
 +
*Virulence testing in lab animals
 +
*PCR for detection of virulent isolates
 +
 
 +
 
 +
===Pathogenesis and pathogenicity===
 +
 
 +
*Route of infection: ingestion from pig faeces
 +
*Entry via tonsils, skin or mucous membranes
 +
*Capsule prevents phagocytosis
 +
*Adhere to endothelial cells
 +
*Produce neurominidase which enhances cell penetration
 +
*Septicaemia with vascular damage
 +
*Swelling of endothelial cells, monocyte adherence to vascular walls and hyaline microthrombus formation
 +
*Bacteria localise in synovia of joints and on heart valves during bacteraemia and cause chronic lesions
 +
*Host immune response to persistent bacterial antigens causes long-term damage to the joints
 +
 
 +
 
 +
===[[Swine Erysipelas]]===
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 +
 
 +
===[[Turkey erysipelas]]===
 +
 
 +
 
 +
 
 +
===Sheep infections===
 +
 
 +
*Non-suppurative polyarthritis of lambs from contamination of navel or tail-docking/castration wounds
 +
*Cellulitis and laminitis in older lambs and ewes causing post-dipping lameness - entry through skin abrasions in hoof from contaminated dip
 +
*Valvular endocarditis and pneumonia in ewes reported
 +
**Clinical sighns:
 +
***Cutaneous erysipelas
 +
***Polyarthritis in lambs
 +
***Rarely fatal septicaemia
 +
**Enters via:
 +
***Cuts, abrasions
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***Castration or docking wounds
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***Haematogenous spread -> subacute or chronic '''fibrinopurulent polyarthritis'''
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**Morbidity up tp 50%
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**Affects mostly unthrifty lmbs
 +
**Fibrosis and [[Musculoskeletal Terminology - Pathology|osteophyte]] formation in later stages -> persistent lameness
 +
 
 +
=== Human erysipeloid ===
 +
 
 +
*Infection through skin wounds from fish and poultry
 +
*Localised cellulitis
 +
*Occasional joint and heart disease after haematogenous spread if untreated
 +
 
 +
 
 +
[[Category:Bacteria_miscellaneous]] [[Category:Gram_positive_bacteria]] [[Category:Rods]] [[Category:Sheep_Bacteria]] [[Category:Pig_Bacteria]] [[Category:Avian Bacteria]] [[Category:To_Do_-_Bacteria]][[Category:To Do - Major]]

Latest revision as of 13:23, 13 May 2011

Overview

  • Causes erysipelas in pigs and turkeys worldwide
  • Arthritis and discospondylitis in pigs as well as cutaneous lesions
  • Occasionally causes arthritis in sheep and disease in other animals
  • Causes erysipeloid, a localised cellulitis in humans
  • Found in porcine tonsils - 50% of pigs are thought to be carriers
  • Bacteria excreted in faeces and oronasal secretions
  • Survive in soil for less than 35 days
  • Present on fish


Characteristics

  • Gram-positive, small rod (smooth form) or filamentous (rough form)
  • Facultative anaerobe
  • Non-motile
  • Catalase negative, oxidase negative, coagulase positive
  • Grow on nutrient agar; growth enhanced by addition of blood or serum
  • Small colonies with incomplete haemolysis in 48 hours
  • Hydrogen sulphide formed as black central line in TSI agar
  • Growth over wide rangs of temperatures and pH


Identification and diagnosis

  • Isolates from acute infections produce smooth colonies; 1.5mm diamteter, convex and circular with even edges
  • Isolates from chronic infections produce rough colonies; larger, flat and opaque colonieswith irregular edges
  • Biochemical tests
  • Serotypying according to a heat-stable peptidoglycan extracted from the cell wall
  • Virulence testing in lab animals
  • PCR for detection of virulent isolates


Pathogenesis and pathogenicity

  • Route of infection: ingestion from pig faeces
  • Entry via tonsils, skin or mucous membranes
  • Capsule prevents phagocytosis
  • Adhere to endothelial cells
  • Produce neurominidase which enhances cell penetration
  • Septicaemia with vascular damage
  • Swelling of endothelial cells, monocyte adherence to vascular walls and hyaline microthrombus formation
  • Bacteria localise in synovia of joints and on heart valves during bacteraemia and cause chronic lesions
  • Host immune response to persistent bacterial antigens causes long-term damage to the joints


Swine Erysipelas

Turkey erysipelas

Sheep infections

  • Non-suppurative polyarthritis of lambs from contamination of navel or tail-docking/castration wounds
  • Cellulitis and laminitis in older lambs and ewes causing post-dipping lameness - entry through skin abrasions in hoof from contaminated dip
  • Valvular endocarditis and pneumonia in ewes reported
    • Clinical sighns:
      • Cutaneous erysipelas
      • Polyarthritis in lambs
      • Rarely fatal septicaemia
    • Enters via:
      • Cuts, abrasions
      • Castration or docking wounds
      • Haematogenous spread -> subacute or chronic fibrinopurulent polyarthritis
    • Morbidity up tp 50%
    • Affects mostly unthrifty lmbs
    • Fibrosis and osteophyte formation in later stages -> persistent lameness

Human erysipeloid

  • Infection through skin wounds from fish and poultry
  • Localised cellulitis
  • Occasional joint and heart disease after haematogenous spread if untreated