Difference between revisions of "Erysipelothrix rhusiopathiae"

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===Overview===
 
===Overview===
  
 
*Causes erysipelas in pigs and turkeys worldwide
 
*Causes erysipelas in pigs and turkeys worldwide
*[[Joints Inflammatory - Pathology#In Pigs|Arthritis and discospondylitis in pigs]] as well as [[Bacterial skin infections - Pathology#Systemic bacterial infections|cutaneous lesions]]
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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]]
*Occasionally causes [[Joints Inflammatory - Pathology#In Sheep|arthritis in sheep]] and disease in other animals
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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
 
*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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===[[Swine Erysipelas]]===
  
*Carrier pigs act as reservoir of infection
 
*Organisms excreted in faeces of acutely-affected pigs
 
*Ingestion of contaminated food and water, or via skin abrasions
 
*Clinical outcome depends on susceptibility of pigs and virulence of strain
 
*Pigs susceptible after maternal antibody waned (after 3 months) and before protective immunity acquired (3 years)
 
*Change in diet, extremes of temperature and fatigue thought to predispose to infection
 
*Septicaemic form:
 
**Acute; incubation period 2-3 days
 
**Pigs found dead, febrile, depressed, recumbent or with stilted gait
 
**Mortality high
 
**Pregant sows abort
 
*Cutaneous form:
 
**Diamond skin lesions
 
**Fewer systemic signs, mortality rates lower
 
**Pigs febrile with small, pink/purple raised areas or extensive diamond-shaped plaques over skin
 
**Lesions may resolve within a week, or become necrotic and slough
 
*Arthritis:
 
**Older pigs, chronic
 
**Stiffness, lameness, non-weight bearing on affected limbs
 
**Joint lesions with erosion of articular cartilage, fibrosis and ankylosis
 
**Strong impact on productivity
 
*Chronic valvular endocarditis:
 
**Vegetatic thrombosis of mitral valves
 
**Asymptomatic or congestive heart failure and sudden death with stress
 
*Diagnosis:
 
**Diamond-shaped skin lesions
 
**Haematology and post mortem, especially liver, [[Spleen - Anatomy & Physiology|spleen]], heart valves, synovial tissues
 
**Slender Gram-positive rods on microscopy of acute lesions; filamentous forms in chronic lesions and smears
 
**No growth on MacConkey agar
 
**Colonial characteristics and biochemical tests
 
*Treatment:
 
**Penicillin and tetracyclines for acute infections
 
**Hyperimmune serum
 
*Control:
 
**Hygience
 
**Cull chronic cases
 
**Isolate affected pigs
 
**Live attenuated or inactivated vaccines
 
  
===Turkey erysipelas===
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===[[Turkey erysipelas]]===
 +
 
  
*Affects birds of all ages
 
*Excreted in semen, causing death of turkey hens 4-5 days after AI
 
*Septicaemia
 
*High mortality
 
*Dark, swollen snoods
 
*Enlarged friable liver and [[Spleen - Anatomy & Physiology|spleen]] on post mortem
 
*Arthritis and vegetative endocarditis and emaciation with chronic infections
 
*Inactivated vaccine
 
  
 
===Sheep infections===
 
===Sheep infections===
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*Cellulitis and laminitis in older lambs and ewes causing post-dipping lameness - entry through skin abrasions in hoof from contaminated dip
 
*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
 
*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 ===
  
===Human erysipeloid===
+
*Infection through skin wounds from fish and poultry
 +
*Localised cellulitis
 +
*Occasional joint and heart disease after haematogenous spread if untreated
  
*Infection through skin wounds from fish and poultry
+
 
*Localised cellulitis
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[[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]]
*Occasional joint and heart disease after haematogenous spread if untreated
 

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