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| − | ===Overview===
| + | <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 erysipelas in pigs and turkeys worldwide
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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]]
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| − | *Occasionally causes [[Infectious Arthritis#In Sheep|arthritis in sheep]] and disease in other animals
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| − | *Causes erysipeloid, a localised cellulitis in humans
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| − | *Found in porcine tonsils - 50% of pigs are thought to be carriers
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| − | *Bacteria excreted in faeces and oronasal secretions
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| − | *Survive in soil for less than 35 days
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| − | *Present on fish
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| − | | + | *Causes [[Joints - inflammatory#In Sheep|arthritis in sheep]] and [[Joints - inflammatory#In Pigs|arthritis in pigs]] |
| − | ===Characteristics===
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| − | *Gram-positive, small rod (smooth form) or filamentous (rough form) | |
| − | *Facultative anaerobe
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| − | *Non-motile
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| − | *Catalase negative, oxidase negative, coagulase positive
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| − | *Grow on nutrient agar; growth enhanced by addition of blood or serum
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| − | *Small colonies with incomplete haemolysis in 48 hours
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| − | *Hydrogen sulphide formed as black central line in TSI agar
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| − | *Growth over wide rangs of temperatures and pH
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| − | ===Identification and diagnosis===
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| − | *Isolates from acute infections produce smooth colonies; 1.5mm diamteter, convex and circular with even edges
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| − | *Isolates from chronic infections produce rough colonies; larger, flat and opaque colonieswith irregular edges
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| − | *Biochemical tests
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| − | *Serotypying according to a heat-stable peptidoglycan extracted from the cell wall
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| − | *Virulence testing in lab animals
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| − | *PCR for detection of virulent isolates
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| − | ===Pathogenesis and pathogenicity===
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| − | *Route of infection: ingestion from pig faeces
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| − | *Entry via tonsils, skin or mucous membranes
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| − | *Capsule prevents phagocytosis
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| − | *Adhere to endothelial cells
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| − | *Produce neurominidase which enhances cell penetration
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| − | *Septicaemia with vascular damage
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| − | *Swelling of endothelial cells, monocyte adherence to vascular walls and hyaline microthrombus formation
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| − | *Bacteria localise in synovia of joints and on heart valves during bacteraemia and cause chronic lesions
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| − | *Host immune response to persistent bacterial antigens causes long-term damage to the joints
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| − | ===[[Swine Erysipelas]]===
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| − | ===[[Turkey erysipelas]]===
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| − | ===Sheep infections===
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| − | *Non-suppurative polyarthritis of lambs from contamination of navel or tail-docking/castration wounds
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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
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| − | *Valvular endocarditis and pneumonia in ewes reported
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| − | **Clinical sighns:
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| − | ***Cutaneous erysipelas
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| − | ***Polyarthritis in lambs
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| − | ***Rarely fatal septicaemia
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| − | **Enters via:
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| − | ***Cuts, abrasions
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| − | ***Castration or docking wounds
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| − | ***Haematogenous spread -> subacute or chronic '''fibrinopurulent polyarthritis'''
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| − | **Morbidity up tp 50%
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| − | **Affects mostly unthrifty lmbs
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| − | **Fibrosis and [[Musculoskeletal Terminology - Pathology|osteophyte]] formation in later stages -> persistent lameness
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| − | === Human erysipeloid ===
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| − | *Infection through skin wounds from fish and poultry
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| − | *Localised cellulitis
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| − | *Occasional joint and heart disease after haematogenous spread if untreated
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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]]
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