Week 4 ,, Cutaneous Mycoses (Dermatophytosis)

What is/are the caustive agent(s) of Dermatophytosis?

All of them

Antropophilic Dermatophytes

Trichophyton rubrum

Geophilic Dermatophytes

Microsporum gypseum

Which one isn’t a zoophilic dermatophyte?

Tripchophyton rubrum

Dermatophytosis Diagnosis in Clinical Appearance

Wood lamp (UV, 365nm) ,, M. audouinii, M. canis, and T. schoenleinii fluoresce blue-green or green-yellow under ultraviolet light

Microsporum

Infects skin and hair

Epidermophyton

Infects skin and nail

Trichophyton

Infects skin, nail, and hair

What type of macroconidium does Mirosporum contain?

Fusiform

What type of macroconidium does Epidermophyton contain?

Clavate

What type of macroconidium does Trichophyton contain?

(Few) Cylindrical clavate/fusifrom singles in clusters

Does Microsporum contain microconidium?

Yes

Does Epidermophyton contain microconidium?

No

Does Trichophyton contain microconidium?

Yes

Microsopy of Microsporum canis

Large, verrucose thick-walled, multi-septate, spindle/fusiform macroconidia directly from the hyphae

Microsopy of Epidermophyton floccosum

Clavate conidia smooth-walled conidia and thick-walled chlamydoconidia ,, microconidia absent

Microsopy of Tripchophyton mentagrophytes, T. rubrum, or T. tonsular

Smooth thick-walled, elongate, cigar-shaped, multiseptate macroconidia ,, microconidia ovale, singly or in grape-like cluster

Identify the Fungi

Microsporum canis

Identify the Fungi

Tripchophyton mentagrophytes, T. rubrum, or T. tonsular

Identify the Fungus

Epidermophyton floccosum

T. mentagrophytes

Urea positive

T. rubrum

Able to use sucrose

T. rubrum (2)

Produces a blood red pigment on cornmeal agar

M. canis

Grows on polished rice grains