LEC 4 - Aspergillus + Dermatophytes Flashcards
Aspergillus species
Fumigatus
– and –
Flavus
What does flavus do pathologically?
Hepatotoxicity
Symptoms of A. Fumigatus: Cats/Dog
Sinonasal discharge
Symptoms of A. Fumigatus: Birds
Air saculitis
Symptoms of A. Fumigatus: Equine
Guttural pouch mycosis
How does Aspergillus cause disease in an animal?
Respiratory infection due to spore inhalation
Tissue invasion possible
What is the major virulence factor in Aspergillus?
Gliotoxin
Describe: Gliotoxin
Mucocillary apparatus
– and –
Immune evasion
What are ways that you can diagnose Aspergillus?
Fungal Culture
Fungal serology
Rhinoscopy/biopsy/histology
What fungal culture is used to grow aspergillus?
Sab dex
What color is a colony of aspergillus on fungal culture?
Blue/green to black/light tan
What can aspergillus from a fungal culture be stained with?
Lactophenol cotton blue
What are the four basic kinds of fungal cultures?
Sabaroud dextrose
Potato dextrose
Birdseed agar
DTM
How can you tell penicillin apart from aspergillus?
Branching in the hyphae
Systemic treatment: Aspergillus
Azoles
Topical treatment: Aspergillus
Azoles
Trephination
What are the two species of Microsporum spp?
Canis
– and –
Gypseum
What are the two species of Trichophyton spp.?
Mentagrophytes
– and –
Verrucosum
Describe: Microsporum
Spindle shaped
Thick walled
Rough
Describe: Trichophyton
Cigar shaped macroconidium
Smooth, thin walled
What type of trichophyton attacks food animals?
T. Verucosum
Describe T. Verucosum
Chain chlamydospores
What are the clinical signs of a dermatophyte infection?
Focal/Multifocal alopecia w/ scaling
Inflammatory ring
What happens to Persian cats that have a dermatophyte infection?
Pseudomycetomas
What are the two differential diagnosis for dermatophytes?
Poxvirus
– and –
Sarcoptic mange
What is the treatment for a dermatophyte infection?
Isolation/Environmental clean up
Miconazole/Enilconazole topical
Debridement
Stain: Dermatophytes
PAS
– or –
Silver staining
Culture growth: Dermatophytes
Sab dex
– or –
DTM
Describe: DTM
Alkaline metabolites from dermatophyte growth
– and –
Phenol red
What is contained in DTM?
Sab dex w/ cycloheximide + phenol red
What is the pathogenesis of dermatophytes?
Arthrospores adhere to keratinized tissues
Hyphae grow outward and trigger local inflammation
Cell-mediated response/transient immunity