Mycology Week Three Worksheets

Alternaria sp.

• Macroscopic:

  • front: cottony, black to grey to olive brown

  • reverse: black-brown

• Microscopic:

  • conidiophores support mainly chained poroconidia: multi-celled, club-shaped poroconidia contain horizontal or vertical septa

Bipolaris sp.

• Macroscopic:

  • front: matted center and raise grayish periphery, first grayish brown, becoming black

  • reverse: black

• Microscopic:

  • bent-knee shaped conidiospore supports multi-celled, canoe-shaped poroconidia (usually more than 6 cells)

Curvularia sp.

• Macroscopic:

  • front: wooly, dark olive-green to brown or black

  • reverse: dark

• Microscopic:

  • bent-knee shaped conidiophore give rise to large, four-fived celled poraconidia (rounded at the ends)

  • poroconidia have over-enlarged central cells

Epidermophyton sp.

• Macroscopic:

  • front: brownish to yellow to olive-gray or khaki, first lumpy and sparse and then folded in center and groved radically

  • reverse: orange to brownish, sometimes with a thin yellow border

• Microscopic:

  • long, paddle-like macroconidia (with thin, smooth walls) contain 2 to 6 cells and often produced in clusters growing on conidiophore

  • in older cultures see numerous chlamydoconidia; no microconidia

Microsporum canis

• Macroscopic:

  • front: spreading, wooly to cottony, whitish

  • reverse: deep yellow

• Microscopic:

  • rough, thick-celled wall, spindle-shaped macroconidia contain 6 to 15 cells that are on conidiophores; rare club-shaped microconidia are borne singly along the hyphae

• Fluorescene results: positive

Nannizzia (formerly Microsporum) gypsea

• Infects animals very frequently

• Macroscopic:

  • front: flat and spreading and powdery to granular, tan to cinnamon brown

  • reverse: yellow, orange-tan, brownish red, purpish red in spots

• Microscopic:

  • rough, thin-walled, ellptical-shaped macroconidia contain 4 to 6 cells; terminal ends are slighty rounded and are conidiophores; club-shaped microconidia are borne singy along the hyphae

• Flourescence result: positive

Trichophyton mentagrophytes

• Major pathogen of the foot

• Microscopic:

  • front: varies greatly; buff and powdery, white, may become pinkish or yellowish

  • reverse: usually brownish, but may be colorless, yellow, or red

• Macroscopic:

  • thin, smooth-welled, cigar-shaped macroconidia on a conidiophore; small spherical microconidia are produced in grape-like clusters on the hyphae

  • varying numbers of spherical chlamydoconida and spiral shape may be present

• Lab results:

  • vitro hair perforation: +, agar 1: 4+, agar 4: 4+, urease: +, fluorescene: negative

Trichophyton rubrum

• Most frequently isolated dermatophytes infecting humans worldwide affecting the skin and nails

• Macroscopic:

  • front: granular of fluffy, white to buff

  • reverse: deep red or purplish

• Microscopic:

  • “birds on telephone wire”

  • thin, smooth-walled cylindrical with blunt ends macroconidia (sparse or absent) on conidiophores teardropped shaped microconidia are borne in singly along the hyphae

  • older clusters may have chlamyoconidia

• Lab result:

  • vitro hair perforation: 0, agar 1: 4+, agar 4: 4+, urease: 0 or W, fluorescene: negative

Trichophyton tonsurans

• Major pathogen of the scalp

• Macroscopic:

  • front: suedelike with many radical or concentric folds, white, grayish, yellow, or brownish

  • reverse: reddish brown

• Microscopic:

  • thick, smooth-walled, irregular macroconidia are sparse or absent to conidiophores varying shaped microconidia are borne in grape-like clusters or singly along the hyphae (often unstained by LPCB)

• Lab results:

  • vitro hair peforation: Ov, agar 1: +_ or +, agar 4: 4+, urease: + , fluoresence: negative