Difference between revisions of "Erysipelothrix rhusiopathiae"
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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 | ||
− | *[[ | + | *[[Joints - inflammatory#In Pigs|Arthritis and discospondylitis in pigs]] as well as [[Bacterial skin infections#Systemic bacterial infections|cutaneous lesions]] |
− | *Occasionally causes [[ | + | *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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− | + | *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=== | ||
+ | *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 | ||
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− | *Infection through skin wounds from fish and poultry | + | ===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 | ||
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Revision as of 16:45, 17 July 2008
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