Characterized by clusters of colourless to brown swollen phialides at
the tips of colourless to brown, sometimes branched, conidiophores. The
dark brown 1-celled spores (conidia) are produced successively from the
tips of the phialides and collect in wet masses. Species with spores in
chains are referred to Memnoniella. A strong decomposer of
cellulose and thus usually associated with decaying plant materials.
Courtesy of Botany Department, University of Toronto.
sometimes misspelled as Stachybotris is a greenish
black mold that grows on material with a high cellulose content or such as
hay, straw, wicker, and wood chips, as well as building materials such as
ceiling tile, drywall, paper vapor barriers, wallpaper, insulation backing,
cardboard boxes, paper files, fiberboard, the paper covering of gypsum
wallboard, particleboard, jute, dust, and wood when these items become water
damaged. This mold requires very wet or high humid conditions for days or
weeks in order to grow. Most mold spores can begin growing after just
24 hours of wetness, whereas Stachybotrys spores take at least 48 hours of
sustained wetness to begin growth.
Stachybotrys survives and grows best in a continually wet environment such
as a slow water leak in a wall, or in a building suffering from ongoing high
humidity levels. Excessive indoor humidity
resulting in water vapor condensation on walls, plumbing leaks, spills from
showering or bathing, water leaking through foundations or roofs may lead to
growth of many types of mold, including stachybotrys.
spores are rarely airborne, Stachy is usually identified by direct swabs,
or lift tape samples of the mold itself with laboratory analysis of the
collected physical samples. When active and growing in a wet environment,
Stachy can look black, shiny, and slimy. Also, please read the
Stachybotrys from the California Department of Health.
the information provided on the informative mycological website,
genus Stachybotrys has a single well-known species which is Stachybotrys chartarum.
Giant colony on
POTATO DEXTROSE AGAR (PDA)
Potato extract 200 g
Glucose: 20 g
Distilled water: 1 L
Agar: 15 g
Courtesy of the
website Pathogenic Fungi Database.
Slide culture on
Health problems associated with
Stachybotrys chartarum were first noted in the 1930’s and 1940’s when
Russian and Eastern European farm animals specifically horses ate moldy hay
experienced immune system suppression, infection and bleeding that was fatal
with high doses. In 1938, Russian scientists determined the disease was
associated with stachybotrys (then known as S. alternans)
growing on the straw and grain fed to the animals.
first reported human health effects were seen in agricultural workers who
handled the moldy straw or hay. In the early 1940's reports of stachybotryotoxicosis in humans appeared in Russia. People affected where
those who handled or were in close contact with hay or feed grain infested
with stachybotrys. Some of these individuals had burned the straw or
slept on straw-filled mattresses. Common symptoms in humans were dermatitis,
pain and inflammation of the mucous membranes of the mouth and throat, a
burning sensation of the nasal passages, tightness of the chest, cough,
bloody rhinitis, fever, headache and fatigue.
1950's and the 1980's there were continued publications on stachybotryotoxicosis but few that indicated a potential problem with
stachybotrys in homes and buildings. In 1986, Croft et al. reported an
outbreak of trichothecene toxicosis in a Chicago home. Over a 5-year
period, the family complained of headaches, sore throats, flu-like symptoms,
recurring colds, diarrhea, fatigue, dermatitis and general malaise. Air
sampling of this home revealed spores of stachybotrys. The fungus
was found growing on moist organic debris in an uninsulated cold air duct
and on some wood fiber ceiling material. The home had a chronic moisture
problem that favored mold growth. Extracts from the duct debris and
contaminated building materials were toxic to test animals and several
macrocyclic trichothecenes were identified in the extracts. When the mold
problem was corrected, these symptoms associated with trichothecene
collapse of the Twin Towers, many surrounding buildings have been discovered
in NYC that were contaminated with "heavy amounts of stachybotrys."
Most of these buildings were old and water damaged.
With more public
awareness, there will be more and more reports of stachybotrys
appearances. What many news stories have down played, however, is the fact
that there were high amounts of asbestos residue intermingled with the
building debris, thus making the aftermath much more toxic than what may
have been expected. Any aerosol tests that may have been performed would
have picked up several types of evidence of sick-building syndrome. A small
portion of that would have been, at best, stachybotrys of the ruined
muddle of destruction, but it is important to remember everything has been
quite stirred up due to unnatural occurrences to Ground Zero.
More information on Historical Health Effects of Stachybotrys on this link: http://www.mold-help.org/stachybotrys_chartarum.htm.
The picture shows Stachybotrys mold growing in and on drywall.
Courtesy of Case
Western Reserve University.
Learn all about the medical
health effects of Stachybotrys and the medical treatment of
Stachybotrys-caused health problems by reading the
Mold Health Guide.
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.
hyphae, conidiophores, phialides, and conidia are observed. The hyphae and
the conidiophores appear hyaline initially and become darkly pigmented
with age. The conidiophores which may be simple or branched, bear phialides at their apices. These phialides are hyaline or pigmented,
cylindrical in shape, and have swollen upper portions. They form clusters
of 3 to 10. The conidia (4.5 x 9 µm) are oval, hyaline or pigmented,
1-celled, and in clusters.
special precautions other than general laboratory precautions are
data are available.