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| ===''Actinobacillus lignieresii''=== | | ===''Actinobacillus lignieresii''=== |
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− | *Commensal in the mouth of sheep and cattle | + | *Pathogenesis and pathogenicity: |
− | *Penetrates damaged mucosa to cause a granuloma, a condition known as Actinobacillosis | + | **Commensal in the mouth and intestinal tract of cattle and sheep |
− | *Enodogenous, sporadic and chronic infection | + | **Penetrates damaged mucosa to cause chronic granulomatous inflammation of soft tissues, a condition known as Actinobacillosis |
− | *Lesions in the tongue, cheek, lips and sometimes in the lower gut and lungs from aspiration | + | **Enodogenous, sporadic infection |
− | *Often spreads from the site of infection to lymphatics | + | **Lesions in the tongue, cheek, lips and sometimes in the lower gut and lungs from aspiration |
− | *[[Muscles - inflammatory#Wooden tongue|myositis]] and formation of fibrous tissue in the lesions lead to hardening of the tissue, hence the condition is known as 'wooden tongue' in cattle | + | **Often spreads from the site of infection to lymphatics, and may cause pyogranulomatous lymphadenitis |
− | *In sheep abscesses with thick walls are produced | + | **[[Muscles - inflammatory#Wooden tongue|myositis]] and formation of fibrous tissue in the lesions lead to hardening of the tissue, hence the condition is known as 'wooden tongue' in cattle |
− | *Feeding is impaired, causing loss of condition | + | **In sheep abscesses with thick walls are produced |
− | *Recovery with antibiotics | + | **Feeding is impaired, causing loss of condition |
| + | **Infection in the oesophageal groove can cause tympany and enlargement of the retropharyngeal lymph node, causing difficulty in swallowing and breathing |
| + | **Cutaneous lesions in cattle and sheep |
| + | **Contamination of the environment via ulcerating lesions |
| + | *Diagnosis: |
| + | **Induration of tongue |
| + | **Tissue sections may demonstrate pyogranulomatous foci containing club colonies |
| + | **Gram negative rods may be present in smears from exudates |
| + | **Cultures on blood agar and MacConkey agar, incubated for 24-72 hours |
| + | **Blood agar: small, sticky, non-haemolytic clonies |
| + | **MacConkey agar: slow lactose fermentation |
| + | *Treatment: |
| + | **Sodium iodide parenterally, or potassium iodide orally |
| + | **Potentiated sulphonamides or a penicillin/streptomycin combination |
| + | **Rough feed should be avoided |
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