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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===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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*[[Joints - inflammatory#In Pigs|Arthritis and discospondylitis in pigs]] as well as [[Bacterial skin infections#Systemic bacterial infections|cutaneous lesions]]
*Occasionally causes [[Infectious Arthritis#In Sheep|arthritis in sheep]] and disease in other animals
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*Occasionally causes [[Joints - inflammatory#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===
 
 
  
===[[Turkey erysipelas]]===
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*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
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**Pigs found dead, febrile, depressed, recumbent or with stilted gait
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**Mortality high
 +
**Pregant sows abort
 +
*Cutaneous form:
 +
**Diamond skin lesions
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**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===
  
 +
*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 ===
 
  
*Infection through skin wounds from fish and poultry  
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===Human erysipeloid===
*Localised cellulitis  
+
 
 +
*Infection through skin wounds from fish and poultry
 +
*Localised cellulitis
 
*Occasional joint and heart disease after haematogenous spread if untreated
 
*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 16:45, 17 July 2008

BACK TO INFECTIOUS AGENTS AND PARASITES
BACK TO BACTERIA



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

  • 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, 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

  • 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 on post mortem
  • Arthritis and vegetative endocarditis and emaciation with chronic infections
  • Inactivated vaccine

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


Human erysipeloid

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