Chrysosporium Mold SpeciesThe U.S. Government's Occupational Safety and Health Administration [OSHA] lists the following as the health effects of Acremonium mold: Allergen, Irritant, Hypersensitivity pneumonitis, Dermatitis. |
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Taxonomic Classification
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Description and Natural Habitats
Chrysosporium
is a keratinophilic filamentous fungus commonly isolated from soil, plant
material, dung, and birds. It lives on remains of hairs and feathers in
soil. The telemorphs of Chrysosporium spp. are included in the
genera Aphanoascus, Nannizziopsis, and Uncinocarpus.
As well as being a common contaminant, Chrysosporium is
occasionally isolated from human infections. Species
The genus Chrysosporium
contains several species. The most common ones are Chrysosporium
keratinophilum, Chrysosporium tropicum, Chrysosporium
merdarium, Chrysosporium inops, Chrysosporium pannicola,
Chrysosporium queenslandicum, and Chrysosporium zonatum.
Another species of special interest, classified as Emmonsia parva
on the ecological basis, is occasionally named as Chrysosporium parvum
as well. The species of Chrysosporium are
differentiated from each other by the texture of the colony and
morphology, location, and size of the conidia. Also, some species,
particularly Chrysosporium pannicola, do not grow at 37°C. Pathogenicity and Clinical SignificanceChrysosporium species may cause skin infections and onychomycosis in humans. In addition to these superficial infections, Chrysosporium spp. have occasionally been isolated from systemic infections in bone marrow transplant recipients and in patients with chronic granulomatous disease. The high mortality rate of systemic Chrysosporium infections is noteworthy. Macroscopic FeaturesChrysosporium colonies grow moderately rapidly at 25°C. The morphology of the colonies is very variable. They may be granular, woolly, or cottony and flat, or raised and folded in appearance. From the front, the color is white cream, yellow or tan to pale brown. The reverse is white to brown. Microscopic Features Chrysosporium produces hyphae, conidia (aleuriconidia), and arthroconidia. Hyphae are septate while the conidia are hyaline, broad-based, one-celled, and smooth- or rough-walled. These conidia are broader than the vegetative hyphae and occur terminally on pedicels, along the sides of the hyphae, or in intercalary positions. The conidia usually have an annular frill which is the reminant of the hyphal wall that remains after detachment from the hypha. Arthroconidia, on the other hand, are abundant and larger than their parent hyphae in diameter. In addition, Chrysosporium parvum forms enlarged, thick-walled cells (adiaspores) at 37-40°C. Laboratory Precautions
No special precautions other than general laboratory
precautions are required. Susceptibility
Very limited
data are available. Amphotericin B, itraconazole, ketoconazole, and
voriconazole tend to yield low MICs for Chrysosporium
keratinophilum isolates. Fluconazole MICs are relatively higher
than those of the just noted antifungal agents. Flucytosine, on the
other hand, appears to have no in vitro activity against these isolates. |
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The
mycological information gathered and organized in this extensive research
on different Pathogenic Molds was sourced out from the list of
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