Actinomycetes

BACK TO INFECTIOUS AGENTS AND PARASITES BACK TO BACTERIA

• Cause peritonitis in dogs and peritonitis in cattle and peritonitis in pigs

• Nocardia is involved in peritonitis and pleuritis in dogs

• Micropolyspora faeni and Thermactinomyces vulgaris in Bovine Farmers Lung

• Thermactinomyces vulgaris may cause COPD

• Actinomyces may cause granulomatous inflammation.
  • E.g. Actinomyces bovis -the cause of lumpy jaw and in osteomyelitis, may extend to surrounding muscles

• Actinomyces pyogenes in osteomyelitis

• In pyothorax

• Isolated from closed cases of Poll Evil and Fistulous Withers

Overview

• Gram positive bacteria
• Grow slowly on media and produce branching filaments
• Opportunistic infections causing inflammatory responses and granulomatous reactions
• Animal pathogens include Actinomyces, Arcanobacterium, Actinobaculum, Nocardia and Dermatophilus

Actinomyces, Arcanobacterium and Actinobaculum species

• Non-motile, non-spore-forming bacteria
• Anaerobic or facultative anaerobes
• Grow on enriched media
• Arcanobacterium pyogenes formerly known as Actinomyces pyogenes and Corynebacterium pyogenes
• Colonise mucous membranes