Sec 30 Fungal Diseases Flashcards
Trichophyton
Skin
Hair
Nails
Microsporum
Skin
Hair
Epidermophyton
Skin
Nails
Preferring humans over other animals as
natural habitat; often epidemic in nature
Anthropophilic
Asexual spore produced by segmentation of
hyphae
Arthroconidia
Melanin in the cell walls of its conidia,
hyphae, or both results in a darkly colored fungus
Dematiaceous
Dermatophyte growth pattern with spores
forming a sheath on the outside of the hair shaft
Ectothrix
Dermatophyte growth pattern with spore
formation within the hair shaft
Endothrix
Characterized by longitudinally arranged hyphae and air spaces within the hair shaft
Favus
Preferring the soil over humans and animals as
natural habitat;
Geophilic
Long, filamentous fungus cells forming a branching
network called mycelium
Hyphae
Asexual large multinucleate spores produced
by vegetative reproduction
Macroconidia
Asexual small spores produced by vegetative
reproduction
Microconidia
Preferring animals over humans as natural habitat;
Zoophilic
Most common geophilic dermatophyte cultured
from humans
Microsporum gypseum
Most commonly used isolation medium for dermatophytes and it serves as the medium on which most morphologic descriptions are based
Sabouraud’s dextrose agar (SDA)
An alternative isolation medium that contains the pH indicator phenol red. The medium turns red when dermatophyte proteolytic activity increases the pH to 8 or above, and it remains amber with the growth of most saprophytes. Nondermatophyte acidic byproducts turn the medium yellow.
Dermatophyte test medium (DTM)
Microconidia - Smooth walled. Used for identification.
Macronidia - Absent or nondiagnostic.
Trichophyton
Microconidia - Absent or nondiagnostic.
Macroconidia - Rough walled. Used for identification.
Microsporum
Microconidia - Absent
Macroconidia - Smooth walled. Used for identification.
Epidermophyton
Colony: Flat feathery colonies with a central fold and yellow to dull gray-green pigment. Yellow to brown reverse pigment.
Microscopic: Numerous thin and thick-walled, club-shaped macroconidia.
Epidermophyton floccosum
Colony: Flat and white to gray with widely spaced radial grooves. Tan to salmon reverse pigment. Salmon-pink pigment on PDA. No growth on polished rice.
Microscopic: Terminal chlamydoconidia and pectinate (comb-like) hyphae.
Microsporum audouinii
Colony: Flat, white to light yellow, coarsely hairy, with closely spaced radial grooves. Yellow to orange reverse pigment. Yellow on PDA. Growth on polished rice.
Microscopic: Numerous thick walled and echinulate spindle shaped macroconidia with terminal knobs and greater than 6 cells.
Microsporum canis
Colony: Flat and granular with tan to buff pigment, no reverse pigment.
Microscopic: Numerous thin-walled pickle shaped macroconidia without knobs and fewer than 6 cells.
Microsporum gypseum