SYSTEMIC and PATHOGENIC FUNGI

FUNGAL AGENT INFECTION MACROCONIDIA MICROCONIDIA

FUNGAL COLONY CHARACTERISTICS

TEMP.Blood-Enriched

MediumMedium

Lacking Blood Enrichment

Blood-Enriched Medium

Nonblood-Enriched Medium

Blastomyces dermatitidis Blastomycosis

Slow to moderate growth

Young colonies tenacious, older colonies glabrous to woolly

Spicules in center of colony

Oval, pyriform, to globose smooth conidia borne on short, lateral hypha-like conidiosphores

Colonies are cream to tan, soft, moist, wrinkled, waxy, flat to heaped and yeaslike; “tufts” of hyphae often project upward from colonies

Colonies are white to cream to tan, some with drops of exudates present, fluffy to glabrous, and adherent to the agar surface

Hyphae-1-2m in diameter are present; some are aggregated in ropelike clusters; sporulation is rare

Hyphae-1-2m in diameter are present; single pyriform conidia are produced on short to long conidiosphores; some cultures produce few conidia

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Histoplasma capsulatum

Histoplasmosis

Slow growth White to dark

tan with age Woolly, cottony

or granular

Small, one-celled, round, smooth

Tuberculated macroconidia large, round

Colonies are heaped, moist, wrinkled, yeastlike, soft and cream, tan or pink in color; “tufts” of hyphae often project upward from colonies

Colonies are white, cream, tan or gray, fluffy to glabrous; some colonies appear yeastlike and adherent to the agar surface; many variations in

Hyphae-1-2m in diameter are present; some are aggregated in ropelike clusters; sporulation is rare

Young cultures usually have a predominance of smooth-walled macroconidia that become tuberculate with age; macroconidia

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colonial morphology occur

may be pyriform or spherical; some isolates produce small pyriform microconidia in the presence or absence of microconidia

Paracoccidioides brasiliensis

Paracoccidiodomycosis

Slow growth White to beige Colony

glabrous, leathery, flat to wrinkled, folded or velvety

Colonies frequently only produce sterile hyphae

Fresh isolates may produce conidia similar to those of B.dermatitidis

Colonies are heaped, wrinkled, moist, and yeastlike; with age, colonies may become covered with short aerial mycelium and may turn brown

Hyphae-1-2m in diameter are present; some isolates produce conidia similar to those of B.dermatitidis; chlamydoconidia may be numerous, and multiple budding yeast cells 10-25m in diameter may be present

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Rhizopus spp.Mucor spp.

Zygomycetes spp.

Zygomycosis

Colonies are extremely fast growing, wooly, and gray to brown to gray-black

Rhizopus spp.- rhizoids are produced at the base of sporangiophores

Mucor spp.-no rhizoids are produced

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Aspergillus fumigates

Aspergillus flavus

Aspergillus niger

Aspergillus terreus

Aspergillosis

A.fumigatus are usually blue-green to gray-green

A.flavus are yellow-green and black

A.niger are yellow-green to black A.terreus resemble powdered

cinnamon

A.fumigatus- uniserate heads with phialides covering the upper half to two thirds of the vesicle

A.flavus- uniserate or biserate or both with phialides covering the entire surface of a spherical vesicle

A.niger- biserate with phialides covering the entire surface of a spherical vesicle; conidia are black

A.terreus-biserate with phialides covering the entire surface of a hemispherical vesicle; aleurioconidia are formed on submerged hyphae

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Coccidioides immitis

Coccidioidomycosis

Rapid growth White to tan to

dark gray Young colonies

tenacious, older colonies cottony

Tend to grow in concentric rings

Alternating one-celled, “barrel-shaped” arthroconidia with disjunctor cells

Colonies may be white and fluffy to greenish on blood-enriched media; some isolates are yeastlike, heaped, wrinkled, and membranous

Colonies usually are fluffy white but may be pigmented gray, orange, brown or yellow; mycelium is adherent to the agar surface in some portions of the colony

Chains of alternate, barrel-shaped arthroconidia are characteristic; some arthroconidia may be elongated; hyphae are small and often arranged in ropelike strands, and racquet forms are seen in young cultures 30⁰C