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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<big><center>[[Bacteria|'''BACK TO BACTERIA''']]</center></big>
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*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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===Overview===
 
===Overview===
  
 
*Causes erysipelas in pigs and turkeys worldwide
 
*Causes erysipelas in pigs and turkeys worldwide
*[[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 infects sheep and other animals
*Occasionally causes [[Infectious Arthritis#In Sheep|arthritis in sheep]] and disease in other animals
 
 
*Causes erysipeloid, a localised cellulitis in humans
 
*Causes erysipeloid, a localised cellulitis in humans
 
*Found in porcine tonsils - 50% of pigs are thought to be carriers
 
*Found in porcine tonsils - 50% of pigs are thought to be carriers
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===[[Swine Erysipelas]]===
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===Clinical infections===
 
 
 
 
===[[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 [[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]]
 

Revision as of 12:02, 26 May 2008

BACK TO INFECTIOUS AGENTS AND PARASITES
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Overview

  • Causes erysipelas in pigs and turkeys worldwide
  • Occasionally infects sheep and 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


Clinical infections