Download descriptions of several individual mold species

DESCRIPTIONS OF SEVERAL INDIVIDUAL MOLD SPECIES
Acremonium spp.
Where It Is Found: Acremonium spp. is naturally
found in soils, decaying organic matter, and plant
debris. It is also an agricultural contaminant. This
genus can be parasitic or saprophytic to plants and
other living fungi, and some species cause
vascular wilts in trees.
Physical Characteristics: The growth rate of
Acremonium colonies is moderately rapid, maturing
within 5 days. The texture of the colony is
compact, flat or folded, and occasionally raised in
the center. It is glabrous, velvety, and membrane-like at the beginning. Powdery
texture may also be observed. By aging, the surface of the colony may become
cottony due to the overgrowth of loose hyphae. The color of the colony is white,
pale grey or pale pink on the surface. The reverse side is either uncolored or a
pink to rose colored pigment production is observed. Physical characteristics of
Acremonium spp. are the production of conidiophores and long, slender phialide.
The conidia are hyaline, single-celled, and are collected in a slime drop.
Variations/Species: There are approximately
Acremonium spp. in existence today.
100
different
species
of
Possible Health Effects: Acremonium spp. has been known to produce a toxin
from the trichothecene group and may also give off an unpleasant odor due to
the production of volatile organic compounds (VOCs). This fungus is associated
with occupant complaints such as nausea, vomiting and diarrhea. Acremonium
spp. has been isolated from cases of mycetoma, onychomycosis, mycotic
keratitis, infection of the cornea, and infections of artificial implants.
Alternaria spp.
Where It Is Found: Alternaria spp. grows on
organic debris in soil and also parasitizes leaves,
flowers, fruits or vegetables, grains, and
ornamental plants. Outdoors, it may be isolated
from samples of soil, seeds and plants, and is
frequently reported in the air. Alternaria spp. has
been isolated from sewage, leather, stone
monuments, optical instruments, cosmetics,
computer disks, and jet fuel. It is commonly found
indoors in house dust, carpets, textiles, on
horizontal surfaces in building interiors, and
window frames. Alternaria spp. is found in great abundance during the summer
and early fall.
Physical Characteristics: Alternaria spp. grows rapidly. The colony is flat,
downy to woolly and is covered by grayish, short, aerial hyphae in time. The
surface is grayish white at the beginning which later darkens and becomes
greenish black or olive brown with a light border. The reverse side is typically
brown to black due to pigment production.
Variations/Species: There currently are 50 species of Alternaria in existence
today. Alternaria spp. is one of the most common fungi worldwide.
Possible Health Effects: Alternaria spp. spores can deposit in the nose, mouth
and upper respiratory tract causing nasal septum infections. Alternaria spp. has
also been associated with pneumonitis. Alternaria spp. is a common cause of
extrinsic asthma. Acute symptoms include edema and bronchiospasms; chronic
cases may develop pulmonary emphysema. Baker’s asthma is associated with
inhalation of Alternaria spp. conidia present in flour. Other diseases caused by
Alternaria spp. include: Farmer’s lung, mycotic keratitis, skin infections, and
osteomyelitis. Also, the species A. alternata is capable of producing tenuazonic
acid and other toxic metabolites that may be associated with disease in humans
or animals.
Arthrinium spp.
Where It Is Found: Arthrinium is a widespread saprobe. It is
found on plants including sugarcane and especially swamp
grasses & sedges. This genus is often isolated from air near
grassy places in the autumn.
Physical Characteristics: Conidiophores are simple, mostly
hyaline except for thick dark septa. Conidia are dark, singlecelled, broadly fusoid, ovoid with an equatorial germ slit, and are attached on the
side and apex of conidiophore. Colonies grow rapidly and they usually occur in
grape-like masses. The colonies appear woolly to cottony and white with brown
spots on the surface. The reverse side of a colony is pale.
Variations/Species: There are approximately 20 different species of Arthrinium
spp.
Possible Health Effects: Only one species of Arthrinium spp. is considered to
be allergenic. There have been no reported cases of infections or toxin related
diseases in humans or animals.
Aspergillus niger
Where It Is Found: It is a very common environmental
isolate found in a great variety of substrates including
textiles, grains, fruits and vegetables, and soil.
Physical Characteristics: Aspergillus niger appears
powdery in texture. The surface color of Aspergillus
niger colonies is black, while from the reverse side
they appear from white to yellow.
Possible Health Effects: Aspergillus niger is the
third most common Aspergillus species associated
with invasive pulmonary aspergillosis. It is commonly associated with "fungus
ball", a condition where the fungus actively grows in the human lung forming a
ball, without invading lung tissue. Aspergillus niger and Aspergillus fumigatus
have been reported to cause skin diseases and are a common cause of fungal
related ear infections (otomycosis). Aspergillus niger generates many types of
secondary metabolites including malformin B and some of the naptho-yquinones.
Aspergillus spp.
Where It Is Found: Aspergillus spp. is
commonly isolated from forest products,
soil, grains, nuts, cotton, organic debris,
and water-damaged building materials.
Spores can also be found in moist
ventilation systems and house dust.
Physical Characteristics: The
major
features of Aspergillus spp. are the
growth rate, color of the colony, and
thermotolerance. Except for Aspergillus
nidulans and Aspergillus glaucus, the growth rate is rapid to moderately rapid,
while Aspergillus nidulans and Aspergillus glaucus grow slowly. These variations
in
growth
rate
help
in
species
identification.
Aspergillus colonies are downy to powdery in texture. The surface color may vary
depending on the species. The reverse is uncolored to pale yellow in most of the
isolates. However, reverse color may be purple to olive in some strains of
Aspergillus nidulans and orange to purple in Aspergillus versicolor. Aspergillus
fumigatus is a thermotolerant fungus and grows well at temperatures over 40° C.
This property is unique to Aspergillus fumigatus among the Aspergillus species.
Aspergillus fumigatus can grow at a temperature range of 20 to 50° C.
Variations/Species: There are approximately 200 species of Aspergillus spp. It
is one of the most common molds species found around the world.
Possible Health Effects: Sixteen species of Aspergillus spp. have been
documented as etiological agents of human disease but rarely occur in
individuals with normally functioning immune systems. However, due to the
substantial increase in populations of individuals with HIV, chemotherapy
patients and those on corticosteroid treatment, contamination of building
substrates with fungi, particularly Aspergillus spp. is of concern. Aspergillosis is
now the second most common fungal infection requiring hospitalization in the
United States. Many Aspergillus species produce mycotoxins that may be
associated with diseases in humans and other animals. Toxin production is
dependent on the species or strain within the species and on the food source for
the fungus. Some of these toxins are carcinogenic-including aflatoxins and
ochratoxin. Aspergillus spp. is a common cause of extrinsic asthma with
symptoms including edema and bronchiospasms, and chronic cases may
develop pulmonary emphysema.
These fungi are frequently secondary
opportunistic pathogens in patients with bronchiectasis, carcinoma, other
mycosis, sarcoid, and tuberculosis.
Aureobasidium spp.
Where it is found: Aureobasidium is a saprobe, or
weak parasite, Type I & III allergen, and common in
a variety of soils outdoors. It is widespread in the
indoor environment and is common in places that
moisture accumulates like bathrooms, kitchens,
shower curtains, tile grout, and windowsills. Indoors
A. pullulans is often found as a black stain on damp
materials in homes such as painted wood.
Physical Characteristics: Aureobasidium spp. is
identifiable by how it produces black, shiny colonies.
This fungus produces abundant spores, that are single-celled, ovoid, and 5-7
microns in size. It grows moderately rapidly and matures within 7 days of
incubation. The colonies are flat, smooth, moist, yeast-like, mucoid to pasty,
shiny and leathery in appearance. The surface is white, pale pink or yellow at
the beginning and becomes brown to black and velvety with a grayish fringe by
aging. The reverse side is pale or black.
Variations/Species: This genus has 15 species, A. pullulans being the most
common.
Possible Health Effects: This species has also been reported to cause
chromoblastomycosis (in an immunocompromised patient), which is a chronic
cutaneous infection of the skin. There have been rare reports of isolates from
skin lesions, keratitis, spleen abscess in a lymphoma patient, and blood isolate
from a leukemic patient.
Bipolaris spp.
Where It Is Found: Bipolaris spp. is a plant parasite
mostly on subtropical and tropical plants, particularly
to Gramineae. This fungus can grow in semi-dry
environments. It is commonly found in dead or dying
plant debris, soils, and grasses. Bipolaris spp. is a
dematiaceous, filamentous fungus. It is cosmopolitan
in nature and is isolated from plant debris and soil.
Physical Characteristics: Bipolaris spp. is
characterized by how it produces brown conidia that
are multi-celled, elliptical, straight, or curved.
Bipolaris spp. colonies grow rapidly and become mature within 5 days. The
texture of the colonies is velvety to woolly. The surface of the colonies is initially
white to grayish brown and become olive green to black with a raised grayish
periphery as they mature. The reverse sides are also darkly pigmented and olive
to black in color.
Variations/Species: The genus Bipolaris contains several species. Among
these, three well-known pathogenic species are Bipolaris spicifera, Bipolaris
australiensis, and Bipolaris hawaiiensis. Bipolaris spp. is closely related with
Dreschlera spp. and Exserohilum spp.
Possible Health Effects: Some species of Bipolaris spp. are pathogenic to
grasses and animals such as the dog, and may cause nasal mycotic granuloma
in cattle. It has been reported to produce the mycotoxin, sterigmatocystin that
has been shown to cause liver and kidney damage when ingested by laboratory
animals. This fungus is associated with phaeohyphomycosis, a disease
consisting of a group of mycotic infections characterized by the presence of
demataceous septate hyphae. Infections of the eyes and skin by black fungi
could also be classified as phaeohyphomycosis. This fungus causes allergic
fungal sinusitis, characterized by the presence of Bipolaris spp. in the sinuses. In
certain people with severe allergies, the large spores of this fungus can travel to
the sinuses or upper respiratory tract, where they attach to the mucus and grow,
producing an unrelenting allergic reaction that progressively and permanently
damages the sinuses.
Botrytis spp.
Where It Is Found: Botrytis spp. is mostly reported
to be found in tropical and temperate areas. This
fungus is a parasite of plants, soft fruits and
vegetables. It is the cause of leaf/root rot on fruits and vegetables such as
strawberries and onions. It is also known as "gray mold" or “noble rot” on wine
grapes.
Physical Characteristics: The conidia within Botrytis spp. are hyaline or gray in
mass, single-celled, ovoid, and 7-14 x 5-9 microns in size. Colonies grow rapidly
and the texture is woolly. The surface color is white at the beginning and
becomes grey to brown in time. Dark spots may be observed on the surface of
the colony. The reverse side is dark.
Variations/Species: There are approximately 30 different species of Botrytis spp.
Possible Health Effects: Botrytis spp. is a Type I & III allergen, not a known
toxin producer or opportunistic pathogen. Botrytis spp. is known to cause
allergies and induce asthma attacks, and is also a rare agent of keratomycosis.
In some types of agricultural settings, such as greenhouses, the concentration of
aerosolized spores may be greatly enhanced.
Chaetomium spp.
Where It Is Found: Chaetomium spp. is found on
a variety of substrates containing cellulose
including paper and plant compost. Several
species have been reported to play a major role in
decomposition of cellulose-made materials. These
fungi are able to dissolve the cellulose fibers in
cotton and paper and thus cause the materials to
disintegrate. The process is especially rapid under
moist conditions.
Physical Characteristics: In most species of
Chaetomium spp., the spores are lemon-shaped with a single germ pore. The
spore column results from the breakdown of the asci within the body of the
perithecium. The perithecia of Chaetomium are superficial and barrel-shaped,
and they are clothed with dark, stiff hairs. It can produce an Acremonium-like
state (imperfect stage) on fungal media. Chaetomium spp. colonies are rapidly
growing, cottony and white in color initially. Mature colonies become grey to olive
in color. From the reverse side, the color is tan to red or brown to black.
Variations/Species: There are 81 species of Chaetomium spp. in existence
today.
Possible Health Effects:
fever or asthma.
Cladosporium spp.
It is reported to be allergenic, as it may cause hay
Where it is found: Cladosporium spp. is the most
frequently found species in outdoor air in
temperate climates. It is also found on dead
plants, woody plants, food, straw, soil, paint, and
textiles. It is often found indoors, usually in lesser
numbers than outdoors. The dry conidia become
easily airborne and are transported over long
distances. This fungus is often encountered in
dirty refrigerators, especially in reservoirs where
condensation is collected.
On moist window
frames, it can easily be seen covering the whole
painted area with a velvety olive-green layer. Cladosporium spp. often discolors
interior paint, paper, or textiles stored under humid conditions. Houses with poor
ventilation, houses with thatched straw roofs and houses situated in low damp
environments may have heavy concentrations of Cladosporium spp. It is
commonly found on the surface of fiberglass duct liners in the interior of supply
ducts.
Physical Characteristics: Cladosporium spp. colonies are powdery or velvety
olive-green to olive-brown. Other characteristics include dark conidia single- or
double-celled, variable in shape and size, ovoid to cylindrical and irregular,
typically lemon-shaped. Most species of the Cladosporium spp. do not grow at
temperatures above 35° C.
Variations/Species: There are 40 different species of Cladosporium spp. and it is
one of the more common molds found around the world.
Possible Health Effects: Cladosporium spp.’s ability to sporulate heavily, ease
of dispersal, and buoyant spores makes this fungus the most important fungal
airway allergen; and together with Alternaria spp., it commonly causes asthma
and hay fever in the Western hemisphere. A few species of this genus cause
disease, which range from phaeohyphomycosis, a group of mycotic infections
characterized by the presence of demataceous septate hyphae. Infections of the
eyes and skin by black fungi (also classified as phaeohyphomycosis), and
chromoblastomycosis, chronic localized infection of the skin and subcutaneous
tissue that follows the traumatic implantation of the etiologic agent are also
caused by this fungus. Chromoblastomycosis lesions are verrucoid, ulcerated,
and crusted. Skin abscesses, mycotic keratitis and pulmonary fungus ball have
been recorded in immunocompromised patients. It may also cause corneal
infections and mycetoma, characterized by localized infections that involve
cutaneous and subcutaneous tissue, fascia, and bone consisting of abscesses,
granulomata, and draining sinuses, usually in immunocompromised hosts.
Curvularia spp.
Where It Is Found: This fungus can be parasitic or
saprophytic. Curvularia spp. is found in plant
debris, soil, facultative plant pathogens of tropical
or subtropical plants.
Physical Characteristics: The conidiophores are
brown, mostly simple, bearing conidia apically;
dark conidia, end cells lighter, three- to five-celled,
more or less fusiform, typically bent, with one of the
central cells enlarged. Curvularia spp. produces
rapidly growing, woolly colonies. From the front,
the color of the colony is white to pinkish gray initially and turns to olive brown or
black as the colony matures. From the reverse, it is dark brown to black.
Variations/Species: There are approximately 30 different species of Curvularia
spp. known to be in existence today.
Possible Health Effects: Reported to be allergenic. It may cause corneal
infections, mycetoma and infections in immune compromised hosts.
Occasionally a cause of onychomycosis, ocular keratitis, sinusitis, mycetoma,
pneumonia, endocarditis, cerebral abscess, and disseminated infection. Most
cases are from immunocompromised patients.
Epicoccum spp.
Where it is found: Epicoccum spp. is commonly
found as a secondary invader in plants, soil, grains,
textiles and paper products where Cladosporium
spp. and Aureobasidium spp. are present. It is
mostly
saprophytic,
or
weakly
parasitic.
Epicoccum spp. is frequently isolated from air and
occasionally occurs in house dust.
Physical Characteristics: Physical characteristics
of Epicoccum spp. are the production of dark
conidia, several-celled (15-celled), globose,
verrucose, 15-25 microns in diameter, and in a
fruiting body (sporodochium). Epicoccum spp. grows rapidly and produces
woolly to cottony or felty colonies. From the front, the colonies are yellow to
orange, orange to red or pink initially and become greenish brown to black by
aging. From the reverse, the same color is observed but is usually more intense
than in the front view. Epicoccum spp. may produce a diffusible pigment which
turns the color of the inoculated medium to yellow, orange, red or brown. Black
dots (100-2000 µm in diameter) may be observed macroscopically on the colony
surface. These are the tufts of hyphae which have conidiophores on their
surface. These tufts of hyphae are cushion-shaped and nonconvoluted and are
called sporodochia.
Variations/Species: There are 2 species of Epicoccum spp.
Possible Health Effects: Epicoccum spp. is reported to be an allergen but not
in a high frequency. Due to the ability of this fungus to grow at 37° C, it can
cause infection of skin in humans.
Fusarium spp.
Where it is found: Fusarium spp. is commonly
found in soil, plants, grains, and often times
humidifiers.
Physical Characteristics: Physical characteristics
of this fungus include extensive cotton-like
mycelium in culture, often with some tinge of pink,
purple or yellow. Fusarium spp. grows rapidly and
produces woolly to cottony, flat, spreading
colonies. The only slow-growing species is
Fusarium dimerum. From the front, the color of the
colony may be white, cream, tan, salmon, cinnamon, yellow, red, violet, pink, or
purple. From the reverse, it may be colorless, tan, red, dark purple, or brown.
Variations/Species: There are approximately 70 different species of Fusarium
spp.
Possible Health Effects: This fungus produces very harmful toxins, especially
in storage of infected crops. These toxins, known as trichothecene (scierpene)
toxins target the circulatory, alimentary, skin, and nervous systems. Fusarium
spp. can also produce 1) Vomotoxin on grains which has been associated with
outbreaks of acute gastrointestinal illness in humans. 2) T-2 Toxin and related
trichothecenes are some of the deadliest known toxins. If ingested in sufficient
quantity, T-2 toxin can severely damage the entire digestive tract and cause
rapid death due to internal hemorrhage. 3) Fumosin, commonly found in corn and
corn based products, has had recent outbreaks of veterinary mycotoxicosis
causing "crazy horse disease". 4) Zearalenone toxin, which is similar in chemical
structure to the female sex hormone estrogen, targets the reproductive organs.
Fusarium spp. causes keratitis, endophthalmitis, onychomycosis, mycetoma, and
disseminated infection in immunocompromised patients; infections in burn
victims, and systemic opportunistic infections in
severely disabled hosts.
Geotrichum spp.
Where It Is Found: Geotrichum spp. is a yeast found worldwide in soil, water,
air, and sewage, as well as in plants, cereals, and dairy products.
Physical Characteristics: It is characterized by the formation of chains of
colorless, slimy spores (conidia) through the fermentation of vegetative filaments.
Geotrichum spp. strains produce rapidly growing, white, dry, powdery to cottony
colonies, resembling "ground glass." When disturbed on the surface, the colony
becomes yeast-like or slimy. The optimal growth temperature is 25° C. Most
strains either do not grow at all or grow weakly at 37° C.
Variations/Species: There currently are three known species of Geotrichum spp.
Possible Health Effects: This genus can sometimes be pathogenic to man.
Health effects include reports of endocarditis, encephalitis, and osteomyelitis in
immunosuppressed hosts. Pulmonary infections have also been described. Many
of these reports lack proper documentation and may be based on unreliable
identifications. No information is available regarding toxicity. Allergenicity has not
been well studied.
Memnoniella spp.
Where It Is Found: This fungi and Stachybotrys spp. have a worldwide
distribution and are often found together. It is commonly found in plant litter, soil,
many types of plants and trees.
Physical Characteristics: The conidiophores are dark, simple, bearing at apex a
cluster of thick, short phialides; conidia of Memnoniella echinata are very similar
to those of Stachybotrys spp., as they are dark, single-celled, and globose. The
major difference between Memnoniella spp. and Stachybotrys spp. is that the
conidia are in long persistent chains (aggregated in slimy heads in Stachybotrys
spp.). Also the aerodynamic diameter of Memnoniella spp. is smaller and it would
be expected to have an even greater potential to penetrate deep into lungs than
the conidia of Stachybotrys spp.
Variations/Species: There are approximately 5 species of Memnoniella spp.
Memnoniella spp. is very closely related to Stachybotrys spp.
Possible Health Effects: Recent studies on mycotoxins revealed that
Memnoniella echinata can have toxicity similar to that of some isolates of S.
chartarum. In terms of their chemical products, both S. chartarum and M.
echinata produce phenylspirodrimanes, but these two organisms differ in that the
former produces macrocyclic and trichoverroid trichothecenes and the latter
produces griseofulvins. Both produce varying amounts of simple trichothecenes.
Thus, it is suggested that Memnoniella spp. should also be considered potentially
dangerous in indoor air.
Mucor spp.
Where It Is Found: Often found in soils, dead
plant material (hay), horse dung, fruits and fruit
juice. It is also found in leather, meat, dairy
products, animal hair, and jute. It is almost always
in house dust, frequently in air samples and old
dirty carpets. Wood chips and sawdust are often
attacked by M. plimbeus causing "wood chips
disease" and "furrier’s lung". Accumulated dust in
ventilation ducts may contain high concentrations
of viable Mucor spp. spores.
Physical Characteristics: This organism and other
Zygomycetes will grow rapidly on most fungal media. Conidia (aplanospores) are
globose to ellipsoidal, 7-8 microns in diameter, yellowish brown and slightly
rough-walled, and are produced in sporangia that are developed around a
piriform columella with typical projections. Identification is based on the way
sporangia are formed. Colonies of Mucor grow rapidly at 25-30° C. Its fluffy
appearance with a height of several centimeters resembles cotton candy. From
the front, the color is white initially and becomes grayish brown in time. From the
reverse, it is white. Mucor indicus is an aromatic species and may grow at
temperatures as high as 40° C. Mucor racemosus and Mucor ramosissimus, on
the other hand, grow poorly or do not grow at all at 37° C.
Variations/Species: There are approximately 50 different species of Mucor spp.
Possible Health Effects: Asthmatic reactions to Mucor spp. have been
described. It is a Zygomecete fungus that may be allergenic (skin and bronchial
tests). It is an opportunistic pathogenic organism and it may cause mucorosis in
immune compromised individuals. The sites of infections are the lung, nasal
sinus, brain, eye, and skin. Infection may have multiple sites. Mucor spp. causes
rare infections in severely debilitated patients.
Nigrospora spp.
Where It Is Found: This fungus can be a plant
parasite and can be found within soil.
Physical Characteristics: Physical characteristics
include shiny black conidia, single-celled, eggshaped to flattened-spherical, produced singly, and
often have an equatorial colorless line or germ slit.
Nigrospora spp. often appears as white wooly
colonies growing fairly rapidly. The colonies
mature within 4 days. Color of the colony is white
initially and then becomes gray with black areas and turns to black eventually
from both front and reverse. Sporulation may take more than 3 weeks for some
isolates.
Variations/Species: There are 5 species of Nigrospora spp.
Possible Health Effects: Nigrospora is reported to be allergenic. There have
been extremely rare cases of human infection caused by Nigrospora spp.
Paecilomyces spp.
Where It Is Found: Commonly found in soil and
dust, but less frequently in air. P. variotii can cause
paecilomycosis. Paecilomyces spp. can be found
within soil and decaying plant material, composting
processes, legumes, cottonseeds; some species
parasitize insects.
Physical Characteristics: Paecilomyces
spp.
colonies grow rapidly and mature within 3 days.
Paecilomyces crustaceus and Paecilomyces
variotii are thermophilic and can grow well at
temperatures as high as 50° and possibly 60° C. The colonies are flat, powdery
or velvety in texture. The color is initially white, and becomes yellow, yellowgreen, yellow-brown, olive-brown, pink, or violet, depending on the species. The
reverse side is dirty white, buff or brown.
Variations/Species: There
Paecilomyces spp.
are
approximately
30
different
species
of
Possible Health Effects: Linked to wood-trimmers disease and humidifierassociated illnesses. Some members of this genus are reported to cause
pneumonia. It has also been reported as a causative agent of allergic alveolitis. It
may produce arsine gas if growing on arsenic substrate; this can occur on
wallpapers covered with Paris green. Mycotic keratitis in conjunction with
corneal implants, nosocomial infections, endocarditis, infections in
immunocompromised patients have been reportedly linked to Paecilomyces spp.
Pithomyces spp.
Where It Is Found: This fungus is found
mainly growing on decaying plants, grasses,
and soils.
Physical Characteristics: The
most
common isolated species is P. chartarum and
its spores have both longitudinal and transverse septa.
Variations/Species: There are approximately 15 species of Pithomyces spp.
Possible Health Effects: Pithomyces spp. produces a mycotoxin called
sporidesmin which is known to be pathogenic in animals causing facial eczema
and liver damage. Spores are produced at the apex of short side branches of
vegetative filaments, are dark brown, and double- to several celled.
Penicillium spp.
Where It Is Found: Penicillium spp. is often
found in aerosol samples. It is commonly found
in soil, food, cellulose, paint, grains, and
compost piles. It can be found in carpet,
wallpaper, and in interior fiberglass duct
insulation. P. chrysogenum has been found on
building materials including paints, chip boards,
and wallpaper.
Physical Characteristics: The
colonies
of
Penicillium spp. other than Penicillium marneffei
are rapid growing, flat, filamentous, and velvety,
woolly, or cottony in texture. The colonies are
initially white and become blue green, gray green, olive gray, yellow or pinkish in
time. The plate reverse is usually pale to yellowish. Penicillium marneffei is
thermally dimorphic and produces filamentous, flat, radially sulcate colonies at
25° C. These colonies are bluish-gray-green at center and white at the periphery.
The red, rapidly diffusing, soluble pigment observed from the reverse is very
typical. At 37° C, Penicillium marneffei colonies are cream to slightly pink in color
and glabrous to convoluted in texture.
Variations/Species: Approximately 200 species belong to this genus. Penicillium
spp. is commonly found around the world.
Possible Health Effects: Although this fungus is less allergy-provoking than the
other molds, Penicillium spp. is reported to be allergenic (skin) and it may cause
hypersensitivity pneumonitis and allergic alveolitis in susceptible individuals. It
can cause other infections such as keratitis, penicilliosis, and otomycosis. Some
species can produce mycotoxins including 1) Ochratoxin which is damaging to
the kidneys and liver and is also a suspected carcinogen; there is also evidence
that it impairs the immune system. 2) Citrinin that can cause renal damage,
vasodilatation, and bronchial constriction. 3) Gliotoxin which is an
immunosuppressive toxin, and 4) Patulin that is believed to cause hemorrhaging
in the brain and lungs and is usually associated with apple and grape spoilage. It
can also cause extrinsic asthma. P. camemberti has been responsible for
inducing occupational allergies among those who work with soft white cheeses
on which the fungus grows.
Rhizopus spp.
Where It Is Found: Rhizopus spp. is found in forest and cultivated soils,
decaying fruits and vegetables, animal dung and compost. It is a parasitic plant
pathogen on potato, cotton and various fruits.
Physical Characteristics: Nonseptate or sparsely septate broad hyphae (6-15
µm in diameter), sporangiophores, rhizoids (root-like hyphae), sporangia, and
sporangiospores are visualized. Sporangiophores are brown in color and usually
unbranched. They can be solitary or form clusters. Rhizoids are located at the
point where the stolons and sporangiophores meet. Sporangia (40-350 µm in
diameter) are located at the tip of the sporangiophores. They are round with
flattened bases. Apophysis is absent or rarely apparent and columellae are
hemispherical. Sporangiospores (4-11 µm in diameter) are unicellular, round to
ovoid in shape, hyaline to brown in color, and smooth or striated in texture.
Variations/Species: There are approximately 12 species of Rhizopus spp.
Possible Health Effects: It has been reported to be allergenic and it is often
linked to occupational allergy. It may cause mucorosis in immune compromised
individuals. It may also cause zygomycosis (rhino-facial-cranial area, lungs,
gastrointestinal tract, and skin). This disease is associated with the acidotic
diabetes, malnourished children, severely burned patients, and other diseases
such as leukemia and lymphoma, immunosuppressive therapy, or use of
cytotoxins and corticosteroids. The fungi show a propensity for vessel invasion
resulting in embolization and necrosis of surrounding tissue. Rhizopus spp. is
the principal cause of zygomycosis, which occurs primarily in patients suffering
from diabetic ketoacidosis (rhinocerebral disease), malnutrition, severe burns, or
who are immunocompromised.
Sporothrix spp.
Where It Is Found: Sporothrix
spp.
is
a
thermally dimorphic fungus which is distributed
worldwide and isolated from soil, living and
decomposing plants, woods, and peat moss.
Physical Characteristics: Physical
characteristics include conidiophores mostly
simple, single-celled or septate, hyaline, bearing
a loose cluster of dry conidia at apex; conidia, hyaline, single-celled, globose to
ovoid, born on short, prominent denticles. Mostly found as saprophyte.
Variations/Species: There are three species in this genus.
Possible Health Effects: It can cause sporotrichosis. Usually only in
populations which are immune compromised. Sporothrix schenckii is an
occasional cause of human infections.
Sporotrichum spp.
Where It Is Found: Sporotrichum
spp.
is
commonly found on decaying plant matter, wet and
rotting wood and in landscaping mulch.
Physical Characteristics: It is physically similar to
the human pathogen Sporothrix spp. Colonies of
Sporotrichum pruinosum grow rapidly and mature
within 5 days. The texture is velvety to powdery.
From the front, the color is initially white and then
becomes rosy beige, pinkish, yellow or orange.
From the reverse, it is tannish.
Variations/Species: There is only one known species, Sporotrichum pruinosum,
in this genus.
Possible Health Effects: The only information available regarding health
effects are a few rare cases of repeated isolations from respiratory secretions
suggestive of bronchopulmonary colonization.
Stachybotrys spp.
Where it is found: Stachybotrys spp. thrives on
water damaged cellulose rich materials such as
sheet rock, paper, ceiling tiles, cellulose-containing
insulation backing and wallpaper.
Stachybotrys
spp.
typically appears as a sooty black fungus
occasionally accompanied by a thick mass of white
mycelia.
Stachybotrys spp. produces cottony,
rapidly growing colonies which mature in about 4
days. From both front and reverse, the color of the
colony is white initially and turns to black by aging.
Physical Characteristics:
Variations/Species: There are 15 known species of Stachybotrys spp.
Possible Health Effects: The presence of this fungus in buildings is significant
because of the mold’s ability to produce mycotoxins, which are extremely toxic,
such as Satratoxin H. Exposure to these toxins can occur through inhalation,
ingestion or dermal exposure. Symptoms include dermatitis, cough, rhinitis, nose
bleeds, a burning sensation in the mouth and nasal passage, cold and flu
symptoms, headache, general malaise, and fever. Inhalation of conidia may also
induce pathological changes (pneumomycotoxicoses). Satratoxin H has been
reported to be abortigenic in animals and in high doses or chronic low doses it
can be lethal.
Stemphylium spp.
Where It Is Found: Stemphylium spp is found on soil, wood, and
decaying vegetation. Some species found on leaves are plant
pathogens.
Physical Characteristics: Physical characteristics are dark
conidia, with cross and longitudinal septa, variable in shape,
frequently globose, broadly ellipsoid, or ovoid, often constricted
at major septum. Colonies of Stemphylium spp. grow rapidly and
mature in 5 days. They are velvety to cottony in texture. From
the front, the color is gray, brown, or brownish-black. The reverse side is black.
Variations/Species: There are approximately 6 species of Stemphylium spp.
Possible Health Effects:
Stemphylium spp. is reportedly a Type I allergen.
Syncephalastrum spp.
Where It Is Found: Syncephalastrum
usually found in soils and in dung.
spp.
is
Physical Characteristics: Physically it is distinct
with conidiophores erect, branched, tips enlarged,
bearing a head of rod-shaped sporangioles, each
producing a row of nearly spherical conidia.
Colonies of Syncephalastrum spp. grow very
rapidly and the maximum growth temperature is
40° C. The texture of the colony is wooly to cotton
candy-like. From the front, the color is white initially
and turns to dark gray to black in time. The reverse side is pale or yellowishbrown
Variations/Species: This
racemosum.
genus
contains
one
species,
Syncephalastrum
Possible Health Effects: This organism is considered to be primarily nonpathogenic in humans, although a single case of a cutaneous infection was
reported in 1980.
Trichoderma spp.
Where It Is Found: Trichoderma spp. is most
commonly found in soil. Trichoderma spp. is often
found in litter materials (polluted streams, sewage
plants and driftwood). It is found on paper, and in
kitchens on many common tableware materials. T.
viridae is often isolated from indoor air samples
and house dust. Materials such as wood
construction and mineral fiber panels can be very
affected by this fungus. Trichoderma spp. has
been identified on soil, decaying wood, grains,
citrus fruit, tomatoes, sweet potatoes, paper,
textiles, and damp wood.
Physical Characteristics: Colonies of Trichoderma spp. grow rapidly and
mature in 5 days. The colonies are wooly and become compact in time. From
the front, the color is white. As the conidia are formed, scattered blue-green or
yellow-green patches become visible. These patches may sometimes form
concentric rings. Reverse is pale, tan, or yellowish.
Variations/Species: There are approximately 20 species within this genus.
Possible Health Effects: Trichoderma spp. is reported to be allergenic but is
relatively rare. Inhalation of the conidia or the volatile organic compounds may
cause symptoms similar to those of Stachybotrys spp. reactions.
Ulocladium spp.
Where It Is Found: It is commonly found as a
saprophyte on plant materials and soils. Some
species can be also found on dead herbaceous
plants, rotten woods, paper, textiles, and other
organic substrates (cellulose) such as waterdamaged building materials. Ulocladium spp. is
also found in dust and air samples.
Physical Characteristics: Colonies of Ulocladium
spp. grow moderately rapidly. The colonies are
wooly to cottony. From the front and the reverse,
the color is olive brown to black.
Variations/Species: There are approximately 9 species within this genus.
Possible Health Effects: This fungus is reported to be allergenic and
considered cosmopolitan. Ulocladium spp. is known to be a common airway
allergen.
Verticillium spp.
Where It Is Found: Commonly found in soil and
decaying plant matter, known also to cause plant
diseases.
Physical Characteristics: Characterized by whorls of
phialides produced along the length of undifferentiated
filaments on conidiophores. Conidia are colorless, single- or double-celled,
collected in small wet masses. Colonies of Verticillium spp. grow moderately
rapidly or rapidly. The colonies are velvety to wooly. From the front, the color is
white initially and becomes yellowish, red, pinkish-brown, or green. From the
reverse, it is white or brown (rust color).
Variations/Species: There are 4 known species within this genus.
Possible Health Effects: It is normally considered to be nonpathogenic in
humans. A few cases of keratitis have been reported but remain questionable.
Allergenicity has not been well studied.
EXPOSURE TERMS
Exposure Terms Defined
Term
Exposure (Days)
Acute
1-14
Intermediate
15-364
Chronic
365 or more
Four Classes of Immune-Mediated Hypersensitivity Reactions
Type I
Immediate
Type II
Antibody-Mediated Cytotoxic
Type III
Immune Complex
Type IV
Delayed
GLOSSARY OF COMMON TERMS
Abortigenic – a drug or compound that induces the expulsion of an embryo or
fetus.
Acidosis – an abnormal increase in the acidity of the body's fluids, caused either
by accumulation of acids or by depletion of bicarbonates.
Acidotic diabetes – Diabetic Ketoacidosis; occurs when a person maintains high
blood to sugar ratios in the presence of persistant large amounts of ketones.
Aflatoxins – any group of toxic compounds produced by certain molds that
contaminate stored food supplies, such as animal feed and peanuts.
Alimentary – providing nourishment.
Alveolitis – inflammation of the alveoli in the lungs caused by inhaling dust; with
repeated exposure the condition may become chronic.
Apex – the highest point; the vertex.
Apophysis – a natural swelling, projection, or outgrowth of an organ or part, such
as the process of a vertebra.
Asci – a membranous, often club-shaped structure in which typically eight
ascospores are formed through sexual reproduction of ascomycetes.
Ascomycetes – any of various members of a large group of fungi characterized
by the presence of sexually produced spores.
Aspergillosis – an opportunistic infection by a fungus of the genus aspergillus;
characterized by inflammation and lesions of the ear and other organs.
Baker’s asthma – an occupational disease affecting the lungs and characterized
by chronic shortness of breath caused by an allergic reaction to fungal spores
present in flour.
Bronchiectasis – chronic dilation of the brochial tubes.
Bronchiospasms – a sudden involuntary contraction of the bronchioles.
Bronchopulmonary – relating to the bronchial tubes and the lungs.
Carcinogen – a cancer causing agent.
Carcinoma – an invasive malignant tumor derived from epithelial tissue that
tends to metastasize to other areas of the body.
Cerebral abscess – inflammation in the brain caused by bacteria of fungi.
Chromoblastomycosis – chronic cutaneous infection of the skin.
Citrinin – antibiotic and mycotoxin from aspergillus niveus and penicillium
citrinum.
Columellae – any small columnlike structure in various plants and animals, often
forming the central axis of development for the organism or an anatomical
structure.
Concentric rings – rings concentrated around one area.
Conidia – an asexually produced fungal spore.
Conidiophores – a specialized fungal hyphae that produces conidia.
Convoluted – intricate; having many folds or coils.
Corticosteroid – any of the steroid hormones produced by the adrenal cortex or
their synthetic equivalents, such as cortisol and aldosterone.
Cutaneous – of, relating to, or affecting the skin.
Cytotoxins – a substance having a specific toxic effect on certain cells.
Dematiaceous – denoting dark conidia and/or hyphae, usually brown or black.
Denticles – a small tooth or toothlike projection.
Dermatitis – inflammation of the skin.
Diffusible – to pour out and permit or cause to spread freely.
Dimorphic – existing or occurring in two distinct forms.
Disseminated infection – an infection that spreads throughout the body.
Dyspnea – difficulty in breathing, often associated with lung or heart disease and
resulting in shortness of breath.
Edema – swelling due to fluid filling up in body cavities or tissues.
Encephalitis – inflammation of the brain.
Endocarditis – inflammation of the endocardium.
Endophthalmitis – inflammation of the tissues within the eyeball.
Germ slit – a thin, often paler, line running along or across a spore and through
which germination may occur.
Etiologic agent – an agent that causes a disease.
Extrinsic asthma – characterized by attacks of labored breathing, chest
constriction, and coughing caused by an agent from outside the human body.
Facultative – capable of functioning under varying environmental conditions.
Farmer’s lung – an occupational disease affecting the lungs and characterized by
chronic shortness of breath caused by an allergic reaction to fungal spores
present in moldy hay dust that has been inhaled.
Fascia – a sheet or band of fibrous connective tissue enveloping, separating, or
binding together muscles, organs, and other soft structures of the body.
Filament – a chainlike series of cells, as in many algae.
Fumosin – toxin produced by mold.
Fusiform – tapering at each end; spindle-shaped.
Fusoid – somewhat spindle-shaped.
Genus – a taxonomic category ranking below a family and above a species and
generally consisting of a group of species exhibiting similar characteristics.
Glabrous – having no hairs, projections, or pubescence; smooth.
Gliotoxin – a toxic substance which acts mainly against certain viruses by
preventing replication of viral DNA. It also has harmful effects on bacteria and
fungi. It is produced by certain fungi, including Trichoderma viride.
Globose – spherical.
Gramineae – chiefly herbaceous but some woody plants including cereals,
bamboo, reeds and sugar cane.
Granuloma – a mass of inflamed granulation tissue, usually associated with
ulcerated infections.
Griseofulvins – an antibiotic, C17H17ClO6, administered orally for the treatment of
ringworm and other fungal infections of the skin, hair, and nails.
Herbaceous – relating to or characteristic of an herb as distinguished from a
woody plant.
Hyaline – resembling glass, as in translucence or transparency.
Hypersensitivity pneumonitis – chronic progressive form of pneumonia with
wheezing and dyspnea; occurs following exposure to any of a variety of antigens,
sometimes occupational, and many names are given to cases with known types
of exposure (such as farmer's lung, maple bark stripper's lung, chicken plucker's
lung, bagassosis, byssinosis, and humidifier lung).
Hyphae – any of the threadlike filaments forming the mycelium of a fungus.
Inoculate – to give a weak form of a disease to a person or animal, usually by
injection, as a protection against that disease.
Keratitis – inflammation of the cornea.
Keratomycosis – fungal infection of the cornea.
Ketoacidosis – acidosis accompanied by the accumulation of ketone bodies
(ketosis) in the body tissues and fluids, as in diabetic acidosis.
Macroscopically – relating to observations made by the unaided eye.
Malaise – a vague feeling of bodily discomfort, as at the beginning of an illness.
Malformin-B – a phototoxic metabolite produced by aspergillus niger.
Metabolite – any substance produced by the metabolism process in a living
organism.
Mucorosis – an infection with tissue invasion by broad, nonseptate, irregularly
shaped hyphae of diverse fungal species to the lungs, nasal sinus, brain, skin or
eyes.
Mycelia – the vegetative part of a fungus, consisting of a mass of branching,
threadlike hyphae.
Mycetoma – a chronic, slowly progressing bacterial or fungal infection usually of
the foot or leg, characterized by nodules that discharge an oily pus.
Mycosis – a fungal infection in or on part of the body.
Mycotic – dealing with a disease caused by a fungus.
Mycotic keratitis – inflammation of the cornea caused by fungus.
Mycotoxicosis – poisoning caused by ingestion of a mycotoxin.
Mycotoxin – toxin produced by a fungus.
Nonconvoluted – simple; not containing folds or coils.
Nonseptate – not divided by a septum or septa.
Nosocomial infections – pertaining to or originating in the hospital, said of an
infection not present or incubating prior to admittance to the hospital, but
generally occurring 72 hours after admittance, the term is usually used to refer to
patient disease, but hospital personnel may also acquire nosocomial infections.
Ochratoxin – a mycotoxin produced by a fungus of the genus aspergillus spp.
Ocular keratitis – inflammation of the cornea.
Onychomycosis – an infection causing nails to split, flake, and grow too thick.
Osteomyelitis – a usually bacterial infection of bone and bone marrow in which
the resulting inflammation can lead to a reduction of blood supply to the bone.
Otomycosis – an infection due to a fungus in the external auditory canal, usually
unilateral, with scaling, itching, and pain as the primary symptoms.
Ovoid – something shaped like an egg.
Pathogen – an agent that causes disease.
Patulin – a mycotoxin produced by several species of aspergillus spp. and
penicillium spp.
Penicilliosis – infection with fungi of the genus penicillium spp. and characterised
in dogs by chronic sneezing and a nasal discharge.
Perithecium – a small flask-shaped fruiting body in ascomycetous fungi that
contains the ascospores.
Phaeohyphomycosis – a group of superficial and deep infections caused by fungi
that form pigmented hyphae and yeastlike cells in tissue.
Phenylspirodrimanes – potent immunosuppressive agent.
Phialide – a cell that produces conidia.
Piriform columella – the central sterile portion of the sporangium in various fungi
that is in the shape of a pear.
Pneumomycotoxicoses – pathological changes.
Pneumonitis – inflammation of the lung tissue.
Pulmonary emphysema – a condition of the lungs marked by decreased
respiratory function.
Renal damage – kidney damage.
Rhinitis – inflammation of the nasal mucous membranes.
Rhizoids – a rootlike extension of the thallus of a fungus
Saprobe – an organism that derives its nourishment from nonliving or decaying
organic matter.
Saratoxin H – a potent mycotoxin.
Sarcoid – a tumor resembling a malignant tumor arising from connective tissues.
Septa – a thin partition or membrane that divides two cavities or soft masses of
tissue in an organism.
Septate – divided by a septum or septa.
Sinusitis – inflammation of the sinuses or a sinus, especially in the nasal region.
Sporangia – a single-celled or many-celled structure in which spores are
produced, as in fungi, algae, mosses, and ferns.
Sporangiospores – a specialized branch bearing one or more sporangia.
Sporodochium – a cushion-shaped stroma covered with conidiophores in a
fungus.
Sporotrichosis – a chronic infectious disease of domestic mammals and humans,
characterized by nodules or ulcers in the lymph nodes and skin and caused by a
saprophytic or parasitic fungus of the genus Sporothrix, especially S. schenckii,
commonly found in soil and wood.
Sporulate – to produce or release spores.
Sterigmatocystin – a carcinogenic mycotoxin produced in high yields by strains of
the common mold, Aspergillus versicolor.
Stroma – the connective tissue framework of an organ, gland, or other structure.
Subcutaneous – located or placed just beneath the skin.
Sulcate – having narrow, deep furrows or grooves, as a stem or tissue.
T-2 toxin – a potent mycotoxin produced in feedstuffs by several species of the
genus fusarium. It elicits a severe inflammatory reaction in animals and has
teratogenic effects.
Tenuzonic acid – a metabolite found in a strain of the fungus alternaria tenuis
auct, which functions as an antibiotic with antiviral and antineoplastic properties,
and may also act as a mycotoxin.
Thermophilic – requiring high temperatures for normal development, as certain
bacteria.
Trichothecene – any of several mycotoxins that are produced by imperfect fungi
and that include some contaminants of livestock feed and some held to be found
in yellow rain.
Trichoverroid – immunosuppressive.
Tufts – a short cluster of elongated strands, as of yarn, hair, or grass, attached at
the base or growing close together.
Vasodilatation – dilation of a blood vessel, as by the action of a nerve or drug.
Vergosin – antifungal compound.
Verrucose – covered with warts or wartlike projections.
Vomotoxin – deoxynivalenol.
Whorl – ring of leaves or a stem.
Zearalenone – one of a group of compounds known under the general
designation of resorcylic acid lactones.
Zygomycetes – a class of fungi.
Zygomycosis – a fungal infection caused by infection with various fungi from the
class Zygomycetes.