Mycology - Dermatophytes (Ex3) Flashcards
Where are fungi found?
- ubiquitous in environment
- in decaying vegetation, moldy hay, the fridge
- skin and mucus membranes
What are fungi?
- eukaryotes and free-living
- most are saprophytes and non pathogenic
- heterotrophs
Describe the fungal cell-wall
- plant-like, containing glucan, mannan, and chitin, but no cellulose
- membrane contains ergosterol
What are the two forms of fungi?
unicellular - yeast
multicellular - mold with hyphae
What is a mycelium?
a group of tangled hyphae
What is dematiaceous fungi?
What is hyaline fungi?
D: dark-pigmented
H: non-pigmented
Which stain is used for fungal diagnosis?
Lactophenol cotton blue staining
Explain the features of Griseofulvin
- inhibits mitosis
- administered orally
- accumulates in keratin
- only used for dermatophytes
Which drugs inhibit ergosterol?
- polyenes
- azoles
- allylamines
What is phaeohyphomycosis?
a mycotic infection of humans and animals caused by a number of dematiaceous fungi
What is chromoblastomycosis?
- a mycotic infection of cutaneous and subcutaneous tissues characterized by development of dematiaceous, round sclerotic bodies
- infections caused by traumatic implantation of fungal elements into the skin
What is zygomycosis?
any infection due to a member of zygomycetes
- fast-growing, largely saprophytic
What is a mycetoma?
- a mycotic infection of humans and animals caused by a number of different fungi and actinomycetes
- characterized by draining sinuses, granules, and tumefaction
- caused by traumatic implantation
Dermatophytes general features
- Superficial mycosis (Ringworm)
- parasites of keratinized epithelium
- non-invasive, superficial infections
- zoonotic, highly contagious
What are the hosts of the following dermatophytes? Microsporum canis, audouinii, gypsium Trichophyton verrucosum Microsporum nanum Epidermophyton floccossum
M. canis: dogs, cats, humans
T. verrucosum: cattle
M. nanum: pigs
E. floccossum: humans
