Glossary of mold types (continued) |
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Phoma sp. - A common indoor air allergen. It is similar to the
early stages of growth of Chaetomium sp. The species are isolated from soil
and associated plants (particularly potatoes). Produces pink and purple spots
on painted walls (3, 17). It may have antigens which cross-react with those
of Alternaria sp. It will grow on butter, paint, cement, and rubber. It may
cause phaeohyphomycosis, a systematic or subcutaneous disease.
Pithomyces sp. - Grows on dead grass in pastures. Causes facial
eczema in ruminants.
Rhizomucor sp. - The Zygomycetous fungus is reported to be allergenic.
It may cause mucorosis in immune compromised individuals. It occupies a biological
niche similar to Mucor sp. It is often linked to occupational allergy. The
sites of infection are the lung, nasal sinus, brain, eye, and skin. Infection
may have multiple sites.
Rhizopus sp - The Zygomycetous fungus is reported to be allergenic.
It may cause mucorosis in immune compromised individuals. It occupies a biological
niche similar to Mucor sp. It is often linked to occupational allergy. The
sites of infection are the lung, nasal sinus, brain, eye, and skin. Infection
may have multiple sites.
Rhodotorula sp - A reddish yeast typically found in moist environments
such as carpeting, cooling coils, and drain pans. In some countries it is
the most common yeast genus identified in indoor air. This yeast has been
reported to be allergenic. Positive skin tests have been reported. It has
colonized in terminally ill patients.
Sporotrichum sp - Reported to be allergenic. See also Sporothrix
sp. as there is some taxonomic confusion between these two genera. This genera
does not cause sporotrichosis.
Stachybotrys sp. - Aw (water activity) - 0.94, optimum Aw (water
activity) - >0.98. Several strains of this fungus (S. atra, S. chartarum and
S. alternans are synonymous) may produce a trichothecene mycotoxin- Satratoxin
H - which is poisonous by inhalation. The toxins are present on the fungal
spores. This is a slow growing fungus on media. It does not compete well with
other rapidly growing fungi. The dark colored fungi grows on building material
with a high cellulose content and a low nitrogen content. Areas with relative
humidity above 55% and are subject to temperature fluctuations are ideal for
toxin production. Individuals with chronic exposure to the toxin produced
by this fungus reported cold and flu symptoms, sore throats, diarrhea, headaches,
fatigue, dermatitis, intermittent local hair loss, and generalized malaise.
The toxins produced by this fungus will suppress the immune system affecting
the lymphoid tissue and the bone marrow. Animals injected with the toxin from
this fungus exhibited the following symptoms: necrosis and hemorrhage within
the brain, thymus, spleen, intestine, lung, heart, lymph node, liver, and
kidney. The mycotoxin is also reported to be a liver and kidney carcinogen.
Affects by absorption of the toxin in the human lung are known as pneumomycosis.
This organism is rarely found in outdoor samples. It is usually difficult
to find in indoor air samples unless it is physically disturbed. The spores
are in a gelatinous mass. Appropriate media for the growth of this organism
will have a high cellulose content and a low nitrogen content. The spores
will die readily after release. The dead spores are still allergenic and toxigenic.
Percutaneous absorption has caused mild symptoms.
Stemphylium sp. - Reported to be allergenic. Isolated from dead
plants and cellulose materials.
Syncephalastrum sp. - Can cause a respiratory infection characterized
by a solid fungal ball.
Trichoderma sp - It is commonly found in soil, dead trees, pine
needles, paper, and unglazed ceramics. It often will grow on other fungi.
It produces antibiotics which are toxic to humans. It has been reported to
be allergenic (7, 17). It readily degrades cellulose.
Trichophyton sp - Can cause ring worm, athlete's foot, skin, nail,
beard, and scalp (5, 6). Reported to be allergenic. Found on soil and skin.
Ulocladium sp - Has an Aw (water activity) of 0.89. Isolated from
dead plants and cellulose materials. Found on textiles.
Verticillium sp - Conidia (spores) dimensions 2.3-10 x 1-2.6 microns.
Found in decaying vegetation, on straw, soil, and arthropods. A rare cause
of corneal infections.
Wallemia sp - Has an Aw (water activity) of 0.75. Conidia (spores)
dimensions 2.5-3.5 microns. Found in sugary foods, salted meats, dairy products,
textiles, soil, hay, and fruits.
Yeast - Various yeasts are commonly identified on air samples.
Some yeasts are reported to be allergenic. They may cause problems if a person
has had previous exposure and developed hypersensitivity. Yeasts may be allergenic
to susceptible individuals when present in sufficient concentrations.