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Aw (water activity) 0.90. Conidia (spores)
dimensions 12-23 x 8-10 microns. Found in decomposing
vegetation, soil, corn seeds, and in flour. The species
Trichothecium roseum can produce a trichothecene toxin
which may be associated with disease in humans and other
animals. Reported to be allergenic.
Trichothesium species is a filamentous
mitosporic fungus widely distributed on decaying vegetation
and in the soil. The taxonomic classification is kingdom
fungi, Phylum Ascomycota, Class Eusacomycetes. The Order
is Onygenales, Family Artthrodermataceae and finally
genus Epidermophyton. It is commonly considered as a
contaminant. It causes pink rot of apples and is a parasite
of fleshy fungi.
There is no human or animal disease caused by Trichothecium
species that has been reported. Tricothecium roseum
is the only species included in the genus Trichothecium.
The species in the genus include Trichothecium floccosum
and trichothecium roseum. Trichothecium floccosum is
an obsolete synonym of Epidermorphyton floccosum.
Epidermophyton is a filamentous fungus and one of the
three generally classified as dermatophytes. It is distributed
worldwide. The primary host of Epidermorphyton floccosum
which is pathogenic is Man. The natural habitat of the
related but the nonpathogenic species Epidermophyton
is soil. Tricothecium roseum has macroscopic features.
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The colonies of tricothecium grow rapidly
at 25°C and on potato dextrose agar. Colonies are
flat, granular and powdery. Its color is white initially
and becomes pale pink to peach-colored from the front.
The reverse is pale. It does not grow at 37°C. Septate
hyaline hyphae, conidiophores and conidia are observed.
They bear the conidia. The conidia are two-celled, smooth,
slightly thick-walled, hyaline to lightly colored. They
are pear or club-shaped. Their attachment point to the
conidiophore is prominently truncate. They are also
organized side by side and form an elongated cluster.
They overlap to form zigzag pattern at the tip of the
conidiophore.
New conidia are produced and added to the bottom of
the zigzag column. Tricothecium differs from Microsporum
nanum by forming zigzag groups of conidia. This is because
it does not perforate hair in vitro and by being inhibited
with cycloheximide. However, there are no special precautions
other than the general laboratory precautions required.
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