Filamentous - Nocardia/Actinomyces/Dermatophilus Flashcards
Nocardia - descriptive statement
Aerobic, gram positive, saprophytic, partially acid-fast
Nocardia - disease processes
Generalized suppurative & pyogranulomatous processes
Nocardia asteroides=Most common species
Nocardia Transmission
Soil & water, inhalation, trauma & ingestion
Nocardia - diseases
Immunodeficiency in humans & animals - Bovine mastitis!
Nocardia pathogenesis
Suppurative - Variable granulomatous features - Lymph nodes involvement
Nocardia in ruminants
Mastitis! Bovine Farcy! Pneumonia - Abortion - Lymphadenitis
Bovine Farcy DDx!***
Nocardia farcinca - Mycobacterium farcinogenes -M. senegalense
Nocardia in horses/swine
Immunosuppressed animals - Nocardioform placentitis- actually caused by Crossiella equi
Nocardia in dogs/cats
Debilitating, febrile illness, LUMPY JAW
When I say Lumpy Jaw in dogs/cats, you say…
Nocardia cyriacigeneorgica
Actinomyces - Where is it found
Found on oral MM, tooth surfaces, endogenous - infectious - sometimes from bites
Actinomyces pathology
Pyogranulomatous reactions! - Lumpy Jaw in Ruminants, humans & marsupials
When I say Lumpy Jaw in Ruminants, humans & marsupials, you say…
Actinomyces bovis!
Actinomyces bovis pathogenesis
A bovis: oral mucosa–> traumatic event to mandible (alveolar/paralveolar regions) –> chronic rarefying osteomyelitis –> replacement with porous bone, dislodge teeth, can’t chew, mandibular fractures
Main difference from Actinomyces bovis and Nocardiosis?
Actinomyces bovis is very unlikely to disseminate. Stays local, in jaw
Actinomyces in horse
Poll evil and fistulous withers (consider DDx), some cervical lymphadenitis
Actinomyces in Dogs & Cats
A. viscosus - Suppurative serositis, discospondylitis, cutaneous=rare (nodulo-ulcerative lymphangitis)
Actinomyces in Swine
Mastitis, abortion, pneumonia
How to treat Actinomyces infection>
Iodine compounds (careful with toxicity)
Dermatophilus congolensis
Exudative epidermitis
Dermatophilus in cattle
Dermatophilosis or streptothricosis
Dermatophilus in horses
Rain scald - rain rot - grease heal
When I say Rain scald, rain rot, grease heal, you say…
Dermatophilus in horses
When I say strawberry foot rot & lumpy wool in sheep, you say…
Dermatophilus in sheep
What environment is best for dermatophilus?
WET & tropical - high humidity! (Africa & caribbean)
How is dermatophilus spread?
Contact - Fomites - Tick vector (Ambylomma variegatum)
What species of tick spreads dermatophilus?
Amblyomma variegatum
What stain is best for dermatophilus?
Giemsa
What do Dermatophilus congolensis look like under the microscope?
Train tracks!
What is a characteristic sign of Dermatophilus infection?
Paintbrush appearance of removed crust & hair
