Difference between revisions of "Fusobacterium necrophorum"
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| − | + | *Characteristics: | |
| − | + | **Normal inhabitant of mammalian gut; cannot invade normal tissue | |
| − | + | **Pleimorphic - long and filamentous or short cocci | |
| − | + | **Fermentative | |
| − | + | **Haemolytic on blood agar | |
| − | + | **Grey, round, shiny colonies | |
| − | + | **Three biotypes: biotype A has greatest haemolytic activity and virulence | |
| − | + | *Pathogenesis and pathogenicity: | |
| − | + | **Primary pathogen in various diseases of farm animals | |
| − | + | **Mixed bacterial infections | |
| − | + | **Can be secondary to [[Respiratory Viral Infections - Pathology#In Cattle|IBR]] | |
| − | + | **Extracellular haemolysin contributes to infection | |
| − | + | **Heat-stable leucocidin - correlated with biotype and virulence | |
| − | + | **Cytoplasmic toxin - haemolytic | |
| − | + | **LPS endotoxin causes host damage | |
| − | + | **Antibodiy levels rise with age, suggesting that these are not protective | |
| − | + | *Calf diphtheria/necrotic laryngitis [[Respiratory Bacterial Infections - Pathology#In Cattle|in cattle]]: | |
| − | + | **Necrobacillosis of mouth and pharynx of young calves | |
| − | Extracellular haemolysin contributes to infection | + | **Pharyngitis and [[Larynx Inflammatory - Pathology#Infectious causes of laryngitis|laryngitis]] |
| − | + | **Associated with bucket feeding where buckets are contaminated with faeces | |
| − | + | **Bacteria enter through abrasions in the mucosa of the pharynx and larynx | |
| − | + | **Fever, depression, anorexia, salivation, respiratory distress and halitosis | |
| − | + | **Aspiration of necrotic material into lungs may cause fatal [[Lungs Inflammatory - Pathology#Infectious causes of neumonia|bronchopneumonia]] | |
| − | ''F.necrophorum'' | + | **Treatment: potentiated sulphonamides or tetracyclines |
| − | + | *Bovine liver abscesses: | |
| − | + | **Sudden change in diet to a high grain diet causes ruminal acidosis and rumenitis | |
| − | ''' | + | **Ulceration of rumenal mucosa and colonisation by ''F. necrophorum'' and [[Arcanobacter pyogenes|''Arcanobacter pyogenes'']] |
| − | + | **Emboli carry organisms to the liver via the portal vein | |
| − | ''' | + | **Focal necrosis and abscess formation in liver |
| − | + | **Putrid smell | |
| − | + | **Rarely show clinical signs | |
| − | + | **Management important | |
| − | + | *Necrotic rhinitis of pigs: | |
| − | + | **Sporadic condition in young pigs | |
| − | + | **Suppuration and necrosis of snout | |
| − | + | **''F. necrophorum'' and other organisms enter through abrasions in snout mucosa | |
| − | + | **Facial swelling, sneezing, putri nasal discharge | |
| − | + | **Chronic infection - faical deformity | |
| − | + | **Treat with potentiated sulphonamides | |
| − | + | **Occasional pharyngitis/laryngitis [[Respiratory Bacterial Infections - Pathology#In Pigs|in pigs]] | |
| − | + | *Thrush of the hoof: | |
| − | + | **Necrosis of horse hoof associated with poor hygiene, wet conditions | |
| − | + | **''F. necrophorum'' secondary to hoof damage causes localised inflammatory response | |
| − | [[Category: | + | **Thrush especially of hind feet, with putrid discharge in sulci |
| − | + | **Provide dry, clean bedding | |
| − | [[Category: | + | *Black spot of bovine teats |
| + | **Localised necrosis and scab formation of teat orifice and sphincter of dairy cows due to ''F. necrophorum'' | ||
| + | **May predispose to mastitis | ||
| + | *Necrotic wound infections often in association with facultative anaerobes | ||
| + | *Interdigital dermatitis ([[Bacterial skin infections - Pathology#Bacterial pododermatitis|pododermatitis]]) in sheep in association with ''D. nodosus'' and [[Arcanobacter pyogenes|''Arcanobacter pyogenes'']], predisposing to footrot | ||
| + | *Causes [[Respiratory Bacterial Infections - Pathology#Laryngeal chondritis|laryngeal chondritis]] in sheep | ||
| + | *Mixed infections in heel abscesses in sheep | ||
| + | *Mixed infections in [[Pleural Cavity & Membranes Inflammatory - Pathology#Pyothorax (Thoracic empyema)|pyothorax]] | ||
| + | *Mixed infections in aspiration pneumonia and in bovine traumatic reticuloperitonitis and pericarditis | ||
| + | *Involved in [[Bacterial skin infections - Pathology#Subcutaneous abscesses|subcutaneous abscesses]] due to cat bites | ||
| + | *May be involved in [[Nasal Cavity Inflammatory - Pathology#Chronic rhinitis|chronic fibronecrotic rhinitis]] | ||
| + | *[[Bones Inflammatory - Pathology#Osteitis|Osteitis]] | ||
| + | [[Category:Pathogenic anaerobic non-spore-forming Gram-negative bacteri]][[Category:Cattle]][[Category:Pig]][[Category:Horse]][[Category:Sheep]] | ||
Revision as of 14:05, 12 May 2010
- Characteristics:
- Normal inhabitant of mammalian gut; cannot invade normal tissue
- Pleimorphic - long and filamentous or short cocci
- Fermentative
- Haemolytic on blood agar
- Grey, round, shiny colonies
- Three biotypes: biotype A has greatest haemolytic activity and virulence
- Pathogenesis and pathogenicity:
- Primary pathogen in various diseases of farm animals
- Mixed bacterial infections
- Can be secondary to IBR
- Extracellular haemolysin contributes to infection
- Heat-stable leucocidin - correlated with biotype and virulence
- Cytoplasmic toxin - haemolytic
- LPS endotoxin causes host damage
- Antibodiy levels rise with age, suggesting that these are not protective
- Calf diphtheria/necrotic laryngitis in cattle:
- Necrobacillosis of mouth and pharynx of young calves
- Pharyngitis and laryngitis
- Associated with bucket feeding where buckets are contaminated with faeces
- Bacteria enter through abrasions in the mucosa of the pharynx and larynx
- Fever, depression, anorexia, salivation, respiratory distress and halitosis
- Aspiration of necrotic material into lungs may cause fatal bronchopneumonia
- Treatment: potentiated sulphonamides or tetracyclines
- Bovine liver abscesses:
- Sudden change in diet to a high grain diet causes ruminal acidosis and rumenitis
- Ulceration of rumenal mucosa and colonisation by F. necrophorum and Arcanobacter pyogenes
- Emboli carry organisms to the liver via the portal vein
- Focal necrosis and abscess formation in liver
- Putrid smell
- Rarely show clinical signs
- Management important
- Necrotic rhinitis of pigs:
- Sporadic condition in young pigs
- Suppuration and necrosis of snout
- F. necrophorum and other organisms enter through abrasions in snout mucosa
- Facial swelling, sneezing, putri nasal discharge
- Chronic infection - faical deformity
- Treat with potentiated sulphonamides
- Occasional pharyngitis/laryngitis in pigs
- Thrush of the hoof:
- Necrosis of horse hoof associated with poor hygiene, wet conditions
- F. necrophorum secondary to hoof damage causes localised inflammatory response
- Thrush especially of hind feet, with putrid discharge in sulci
- Provide dry, clean bedding
- Black spot of bovine teats
- Localised necrosis and scab formation of teat orifice and sphincter of dairy cows due to F. necrophorum
- May predispose to mastitis
- Necrotic wound infections often in association with facultative anaerobes
- Interdigital dermatitis (pododermatitis) in sheep in association with D. nodosus and Arcanobacter pyogenes, predisposing to footrot
- Causes laryngeal chondritis in sheep
- Mixed infections in heel abscesses in sheep
- Mixed infections in pyothorax
- Mixed infections in aspiration pneumonia and in bovine traumatic reticuloperitonitis and pericarditis
- Involved in subcutaneous abscesses due to cat bites
- May be involved in chronic fibronecrotic rhinitis
- Osteitis