Difference between revisions of "Erysipelothrix rhusiopathiae"
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− | + | ===Overview=== | |
− | |||
+ | *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]] | ||
+ | *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 | ||
+ | *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 [[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
- Clinical sighns:
Human erysipeloid
- Infection through skin wounds from fish and poultry
- Localised cellulitis
- Occasional joint and heart disease after haematogenous spread if untreated