Difference between revisions of "Erysipelothrix rhusiopathiae"
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+ | <big><center>[[Infectious agents and parasites|'''BACK TO INFECTIOUS AGENTS AND PARASITES''']]</center></big> | ||
+ | <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]] | ||
+ | *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 | ||
− | + | *Occasionally infects sheep and other animals | |
− | *Occasionally | ||
*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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− | === | + | ===Clinical infections=== |
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Revision as of 12:02, 26 May 2008
- Causes arthritis in sheep and arthritis and discospondylitis in pigs
- May be involved in cutaneous lesions
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