5. Superficial Mycoses Flashcards
Superficial mycoses of the skin
Tineas
Superficial mycoses of the hair
Piedras
Media that specimens for superficial mycoses are inoculated to
SDA
Causative agent of Tinea versicolor
Malassezia furfur
Superficial infection of the keratinized layers of the skin
Tinea versicolor
Specimen for direct examination for tinea versicolor
Skin
Direct examination:
KOH will show yeastlike and hyphal forms
M. furfur
Lipophilic organism
M. furfur
Special culture method for M. furfur
Since it is lipophilic, add an oil overlay to the SDA and incubate at 37°C
Microscopic:
Thick-walled hyphae
“Yeast”, some budding
M. furfur
Microscopic:
Spaghetti and meatballs
M. furfur
Causative agent of Tinea nigra
Hortaea werneckii
Infection of the keratinized skin layers of the hand
Tinea nigra
How many days will H. werneckii mature?
21 days (slow grower)
Microscopic:
- Septate, thick-walled hyphae
- Yeastlike conidia
- Chlamydospores
- Annellides present (intercalary and lateral)
H. werneckii