|
Toxic Mold Exposure? In Your Home or Office? Welcome To The Most Comprehensive Toxic Mold Website On The Internet!
|
|
Profiles of Mold Commonly Asked About Indoor Molds |
|
|
|
|
| Aspergillus is a common type I & III allergen. They are frequently isolated from forest products, soils, grains, nuts, cotton, organic debris, and water damaged building materials. Spores can also be found in moist ventilation systems and house dust. There are more than 160 different species of Aspergillus, sixteen of which 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 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 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.
Aspergillus niger is the third most common Aspergillus species associated with invasive pulmonary aspergillosis. It is a very common environmental isolate found in a great variety of substrates including textiles, grains, fruits and vegetables, and soil. 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 versicolor can be found mostly in temperate areas in air, house dust, foods, soils, hay, cotton, and dairy products. Its presence in indoor air often indicates signs of moisture problems in buildings, as it is readily found in water damaged building materials. This species produces the mycotoxin sterigmatocystin, which is reported to be carcinogenic to the liver and kidney, and it can cause such symptoms as diarrhea and upset stomach. It also produces the volatile organic compound (VOC) geosmin, this compound causes irritation of the mucus membranes of humans and pets; also causing the characteristic musty, earthy odor often connected with moldy houses. A. versicolor may be in various colors, as the name implies, and is very common and displays great variety in colony pattern and size. |
Stachybotrys
is commonly found in sub-tropical to tropical areas in soil and decaying
plant materials, and is considered a type I & III allergen.
Considerable recent media attention has been focused on the fungi
Stachybotrys chartarum (atra) due to infant deaths in Cleveland from
pulmonary hemosiderosis, which may be associated with contamination of
residences with this fungus. Stachybotrys thrives on water damaged
cellulose rich materials such as sheet rock, paper, ceiling tiles,
cellulose containing insulation backing and wallpaper. The presence of
this fungus in buildings is significant because of the mold’s ability
to produce mycotoxins, such as Satratoxin H, Trichoverrol, and
Cyclosporins that possess cytotoxic, immunological, carcinogenic
effects. 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 abortogenic
in animals and in high doses or chronic low doses it can be lethal. S.
chartarum (atra) produces other macrocyclic and trichoverroid
trichothecenes and, like Memnoniella echinata, produces
phenylspirodrimanes, which are immunosuppressive. Stachybotrys typically
appears as a sooty black fungus occasionally accompanied by a thick mass
of white mycelia. Memnoniella differs from Stachybotrys by producing
conidia in chains. As a general rule, air sampling for Stachybotrys
yields unpredictable results mainly due to the fact that this fungus is
usually accompanied by other fungi such as Aspergillus and Penicillium
that normally are better aerosolized than Stachybotrys. Bulk or surface
sampling of suspect materials can be analyzed in a laboratory for
identification by light microscopy. This fungus is a slow grower on
media, therefore does not compete well with other rapidly growing fungi.
Colonies are powdery in texture, white, pink, orange or black in color.
The species S. chartarum (atra) produces colonies black in color.
IT IS IMPORTANT TO NOTE THAT NOT ALL MOLD THAT IS BLACK IN COLOR IS STACHYBOTRYS! |
| Penicillium A large number of organisms belong to this genus, and identification to species is difficult. Often found in aerosol samples, it is common in soil, food, cellulose, paint, grains, and compost piles. In the indoor environment it is in carpet, wallpaper, and in interior fiberglass duct insulation. Although this fungus causes fewer allergies than other molds, Penicillium is reported to be a type I & III allergen. 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 Ochratoxin, which is damaging to the kidneys and liver and is also a suspected carcinogen; there is also evidence that impairs the immune system. It also produces Citrinin that can cause renal damage, vasodilatation, and bronchial constriction and Gliotoxin, which is immunosuppressive. Patulin is another of its mycotoxins 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 (cheese washer’s lung). P. marneffei is the major pathogenic species causing infections of the lymphatic system, lungs, liver, skin, spleen, and bone, and is also the only species of the genus to have a yeast-like phase induced by temperature. Penicillium sp. are recognized by their dense brush-like spore-bearing structures. | Fusarium is a type I allergen and is an opportunistic pathogen commonly found in soil, plants, grains, and often in humidifiers. While most of the species are found in tropical and subtropical areas, some are found in the soil of cold climates. Some species are plant pathogens causing root and stem rot, vascular wilt or fruit rot, and all require extremely wet conditions for growth. This fungus is the most common cause of mycotic keratitis. It has been isolated from skin lesions of burn patients, nail infections, ear infections, varicose ulcer, mycetoma, osteomyelitis following trauma, and disseminated infections. Infections due to Fusarium are commonly referred to as fusariosis. This fungus produces very harmful toxins, especially in storage of infected crops. These toxins, known as trichothecenes (scierpene) target the circulatory, alimentary, skin, and nervous systems. Fusarium can also produce Vomitoxin, T-2 toxin, Fumonisin, and Zearalenone. Vomitoxin is produced on grains, which has been associated with outbreaks of acute gastrointestinal illness in humans. 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. Fumonisin, commonly found in corn and corn based products, has recently been associated with outbreaks of veterinary mycotoxicosis causing "crazy horse disease". Zearalenone toxin is similar in chemical structure to the female sex hormone estrogen and targets the reproductive organs. Fusarium is one of the most drug resistant fungi. Morphological characteristics of this fungus include extensive cotton-like mycelium in culture, often with some tinge of pink, purple or yellow. |
| Chaetomium
is found worldwide on a variety of substrates including paper, damp
sheetrock, carpet, plant compost, soil, and between layers of wet
plywood. Several species have been reported to play a major role in
decomposition of cellulose-based materials, and is often found indoors
with Stachybotrys. 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. During the Second
World War, countries lost a great deal of equipment to these species.
Chaetomium is reported to have type I & III allergens, and can
produce sterigmatocystin, a mycotoxin shown to cause kidney and liver
damage in laboratory animals. It is not a common human pathogen, but it
has been known to cause skin and nail infections. It is an ascomycete,
and in most species 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. VISIT OUR GLOSSARY :::
|
Cladosporium is widely distributed in air and rotten organic material. C. herbarum is the most frequently found species in outdoor air in temperate climates. 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. It can easily be seen on moist window frames covering the whole painted area with a velvety olive-green layer. Cladosporium often discolors interior paint, paper, or textiles stored under humid conditions. Houses with poor ventilation, houses with thatched straw roofs and houses situated in damp environments may have heavy concentrations of Cladosporium, which will be easily expressed when domestic mold is analyzed. It is commonly found on the surface of fiberglass duct liner in the interior of supply ducts. It is also found naturally on dead & woody plants, food, straw, soils, paint, and textiles. The ability to sporulate heavily, ease of dispersal, and buoyant spores makes this fungus the most important fungal airway allergen; and together with Alternaria, 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. Cladosporium produces the toxins cladosporin and emodin, but neither of these is very toxic. Fungal colonies are powdery or velvety olive-green to olive-brown. Other characteristics include dark conidia that are 1- or 2-celled and are variable in shape and size, typically ovoid to cylindrical in shape. |
| Candida is a yeast that includes about 154 species, six of which are frequently isolated in human infections. It is a part of the normal flora of skin and other mucous membranes in the body. This fungus is naturally found on leaves, flowers, water, organic debris and in soils. The infections caused by this genus are referred to as candidiasis, and almost any organ or system in the body can be affected. It is the cause of infections such as thrush (mouth infection), esophagitis (esophagus infection), cutaneous candidiasis (skin infection), vaginal yeast infections, and deep candidiasis (blood infection). Overgrowth of this fungus is prevented by the presence of “good” bacteria and by the body’s immune system, but if antibiotics decrease the number of bacteria, or if the person’s immune system is weakened because of illness, malnutrition or medications, Candida can multiply and cause symptoms. These species account for more than 85% of all hospitalizations from fungal infections. Mucocutaneous candidiasis is one of the most common manifestations of HIV infection. The environment is not a likely source of exposure for this fungus, and cells from this organism are not usually airborne. Candida albicans is the organism isolated most from patients. Most species of yeast reproduce asexually through a process called budding. The daughter cell is at first much smaller and tends to cling to the parent cell; clumps or chains of cells are often formed. | Alternaria is commonly found in house dust, carpets, textiles, on horizontal surfaces in building interiors, and window frames. It is one of the main fungal causes of allergy, being a common type I & III allergen. Outdoors, it may be isolated from samples of soil, seeds and plants, and is frequently reported in air. The large spore size suggests that this fungus will deposit in the nose, mouth and upper respiratory tract causing nasal septum infections. It has also been associated with hypersensitivity pneumonitis. It 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 conidia present in flour. Other diseases caused by Alternaria 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. Several species are pathogenic to plants and contribute to the spoilage of agricultural products. Alternaria has been isolated from substrates such as sewage, leather, stone monuments, optical instruments, cosmetics, computer disks, and jet fuel. Morphological characteristics include abundant production of conidia that are large (18-83 x 7-18 microns) and multicellular with both transverse and longitudinal septa; conidiophores are dark, mostly simple. Colonies grow fast, are suede-like to floccose, and black to olivaceous-black or grayish in color. |
© 2002-2005 MoldAcrossAmerica, Inc.
MoldAcrossAmerica is not affiliated with any other organization unless specifically stated herein.