Fungal Glossary

Overview

The following general information is available from public domain sources and is only furnished herein as a courtesy.  Note that fungi are presented at genus level and within any genus, various species may exist.

The information should not be considered comprehensive for any particular type of fungi.  A qualified mycologist, microbiologist, or other specialist experienced in fungal microorganisms and their behavior should be consulted for full disclosure on any specific organism.  Qualified health professionals should be consulted for related health effects.
 

Absidia (ab-sid-ee-ah) - Reported to be allergenic. May cause mucorosis in immune compromised in­dividuals. The sites of infection are the lung, nasal sinus, brain, eye and skin. Infection may have multiple sites. A. corymbifera is reported as one of the principal fungi causing zygomycosis. This disease typically involves the rhino-facial-cranial area, lungs, gastrointestinal tract, and skin. The 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. These fungi show an inclination for vessel invasion resulting in embolization and necrosis of surrounding tissue.

Acremonium (ack-ruh-moan-ee-um) - Reported to be allergenic. Isolates have been reported to pro­duce a toxin from the trichothecene group, which is toxic if ingested. It has been associated with households where occupant complaints were nausea, vomiting and diarrhea. It has also been reported to cause mycetomas, infections of the cornea and nails. This fungus can be parasitic to plants or saprophytic and some species cause vascular wilts in trees.

Alternaria (all-ter-nair-ee-a) - This fungus is a large universally occurring genus. Several form-species are found as saprophytes on dead and dying plant parts. Conidia of this fungus are easily carried by the wind. Commonly found in house dust, carpets, textiles, and on horizontal surfaces in building interiors and is one of the main fungal causes of allergy. Outdoors, it may be isolated from samples of soil, seeds and plants, and is frequently reported in air. The large spore size suggests that the spores from 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. Farmer’s lung type of allergy has also been reported recently. Other diseases caused by Alternaria include mycotic keratitis, skin infections, and osteomyelitis. Also, the species Alternaria alternata is capable of producing tenuazonic acid and other toxic metabolites that may be associated with disease in humans or animals. Several species of Alternaria are pathogenic to plants.

Arthrinium (arth-ren-ee-um) - A saprophyte on plants. Common on dead plants, especially grasses, and often isolated from air near grassy places in the autumn.  Generally not considered to have much health significance, but one species is reported to be an allergen.  Organism will grow in conditions similar to Stachybotrys (wet cellulose) therefore, amplified amounts in indoor air could be a warning to conditions conducive to Stachybotrys.  

Arthroconidia - Spores arising from pre-existing cells in the mycelium where adjacent cells collapse to release the mature form (Geotrichum is an example of molds which produce arthroconidia).

Ascospores - Spores produced in a sac-like structure.  When reported, they represent a class of spore that was observed, however, the genus of the organism could not be identified without culturing.

Aspergillus (as-per-jill-us) - There are more than 160 different species of Aspergillus, sixteen of which have been documented as etiological agents of human disease. These species are frequently isolated from forage products, grains, nuts, cotton, organic debris and water damaged organic building materials. The diseases caused by species of Aspergillus are relatively uncommon and are 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 are of concern. Aspergillosis is now the second most common fungal infection requiring hospitalization in the United States. In addition, this genus has been reported to be allergenic. Many 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. Some species can also cause onychomycosis- infection of the nail.

Aureobasidium (are-ee-oh-buh-syd-ee-um) - Saprophytic or weakly parasitic, common in soils. Indoors A. pullulans is often found on damp materials in homes, such as painted wood. A. pullulans has been reported to cause chromoblastomycosis (in an immune compromised patient), which is a chronic cutaneous infection of the skin caused by species of dematiaceous fungi. Morphology is characterized by producing black and shiny colonies when old.

Basidiospores (bah-sid-ee-oh-spores) - A spore formed on a structure known as a basidium.  Characteristic of the Basidiomycete class (i.e. rusts, smuts, and mushrooms).  When reported, they represent a class of spore that was observed, however, the genus of the organism could not be identified without culturing.

Beauveria (bow-vary-uh) - Reported as mainly a parasite of insects (it has been used as biocontrol of insects). B. bassiana is the best known member of this genus and is under research for bio­control of insects. B. alba commonly occurs in indoor environments and appears to be less strongly associated with insects.

Botrytis (bow-try-tus) - This fungus is a parasite of plants, soft fruits and vegetables. It is also known as "gray mold". Botrytis is known to cause allergies and induce asthma attacks.  In some types of agricultural settings, such as greenhouses, the concentration of aerosolized spores may be greatly enhanced.  Botrytis is also used in some types of wine production.

Chaetomium (kay-toe-mee-um) - 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. It is reported to be allergenic. It is an ascomycete, in most species, the spores are lemon-shaped, with a single germ pore. Organism will grow in conditions similar to Stachybotrys (wet cellulose) therefore, amplified amounts in indoor air could be a warning to conditions conducive to Stachybotrys.  On water-damaged drywall paper, colonies of Chaetomium and Stachybotrys may be growing together and can not be distinguished by the naked eye.

Chrysonilia (kris-o-nil-ee-a) - Contaminant, brightly colored, fast growing mold which spreads easily.  Health effects are not yet known.  It is found in soil, breads, and contaminated laboratory cultures.

Cladosporium (clad-oh-spore-ee-um) - 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. On moist window frames, it can easily be seen 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 low 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 on dead plants, woody plants, food, straw, soil, 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 immuno- compromised 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. Fungal colo­nies are powdery or velvety olive-green to olive-brown.

Curvularia (curve-you-lair-ee-a) - Contaminant/opportunistic pathogen.  Found in air, soil and textiles.  Reported to cause infections in eyes and sinuses.

Dematiaceous Molds (dim-ah-tie-ay-shush) - A very generic morphological description used for vari­ous brown molds that cannot be identified because of undistinguishable spore/structure or because of too much environ­mental damage to the mold structures.  This identification generally excludes many of the common toxic and more infectious molds found indoors, but on some occasions when the mold is very weathered or damaged, this category could potentially include mold from Alternaria, Epicoccum, Ulo­cladium or others.

Drechslera/Bipolaris Group (dresh-lair-uh; by-pole-air-us) - Found on grasses, grains and decaying food.  Contaminant/opportunistic pathogen.  Reported to cause infections of eyes, nose, lungs and skin.

Epicoccum (epp-ee-cock-um) - It is commonly found as a secondary invader in plants, soil, grains, textiles and paper products where Cladosporium and Aureobasidium are present. It is mostly saprophytic, or weakly parasitic. Epicoccum is frequently isolated from air and occasionally occurs in house dust. 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.

Exophiala (ex-oh-fy-all-ua) - Contaminant/opportunistic pathogen.  Commonly found in soil, decaying wood, and various other wet materials because it thrives in water laden environments.  Indoors it can be found in air condi­tioning systems, humidifiers, and other surfaces in frequent contact with moisture.  Some species linked to occasional skin infections and various other subcutaneous lesions.  Allergenic effects and toxicity are not well studied.

Fusarium (few-sarh-ee-um) - Commonly found in soil, plants, grains, and often times it is found in humidifiers. This fungus is the most common cause of mycotic keratitis. This mold has been isolated from skin lesions on burn patients, nail infections, ear infections, varicose ulcer, mycetoma, osteomyelitis following trauma, and disseminated infection. 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 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 severally damage the entire digestive tract and cause rapid death due to internal hemorrhage; 3) Fumosin, commonly found in corn and corn based products, with recently outbreaks of veterinary mycotoxicosis causing "crazy horse disease"; 4).  Zearalenone toxin which is similar in chemical structure to the female sex hormone estrogen and targets the reproductive organs. 

Geotrichum (gee-oh-trick-um) - This fungus is commonly found in dairy products and also in soils. This genus can sometimes be pathogenic to man. It is characterized by the formation of chains of colorless, slimy spores (conidia) through the fermentation of vegetative filaments.  Some species of Geotrichum have strong odors.

Gliocladium (glee-oh-clay-dee-um) - This fungus occurs in soil or decaying plant matter as parasites of other fungi. Reported to be allergenic. 

Memnoniella (mimm-non-ee-ella) - Cellulolytic fungus very closely related to Stachybotrys. Both fungi have a worldwide distribution and often found together, and commonly found in soil. 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 should also be considered potentially dangerous in indoor air. The major difference between the two fungi is that the conidia are in long persistent chains (aggregated in slimy heads in Stachy­botrys). Also the aerodynamic diameter of Memnoniella is smaller and it would be expected to have an even greater potential to penetrate deep into lungs than the conidia of Stachybotrys.

Mucor (mhew-core) - 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 spores. Asthmatic reac­tions to Mucor 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. This organism and other Zygomycetes will grow rapidly on most fungal media. 

Myxomycete/Rusts/Smuts (mix-oh-my-seat) - A group of fungal organisms that are generally associated with plants and/or wood decay. Ubiquitous, type I allergen. Dispersed by wind in the dry phase, while the wet amoebic phase is motile. Myxomycetes exhibit characteristics of protozoans and fungi. Indistinguishable from smuts under 600x microscopy.

Paecilomyces (pay-sill-oh-my-sees) - Commonly found in soil and dust, less frequently in air.  P. vari­otii can cause paecilomycosis.  Linked to wood-trimmers disease and humidifier associated illnesses. Some members of this genus are reported to cause pneumonia. It has also been reported as causative agent of allergic alveolitis. It may produce arsine gas if growing on arsenic substrate, this can occur on wallpapers covered with Paris green.

Penicillium (pen-uh-sill-ee-um) - A wide number of organisms belong to this genus. Identification to species is difficult.  Often found in aerosol samples. Commonly found in soil, food, cellulose, paint, grains, and compost piles. It is commonly found in carpet, wallpaper, and in interior fiberglass duct insulation. Although this fungus is less allergy-provoking than the other molds, Penicillium 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 impairs the immune system. 2). Citrinin that can cause renal damage, vasodilatation, and bronchial constriction. 3). Gliotoxin which is an immunosuppressive toxin, and 3). 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. P. chrysogenum has been found on building materials, including paints, chip boards, and wall­paper.

Pithomyces (pith-oh-my-sees) - This fungus is found mainly growing on decaying plants, specially grasses. It produces a mycotoxin called sporidesmin (a piperazinedione) known to be pathogenic in animals causing facial eczema and liver damage.

Rhizopus (rye-zo-puss) - Fungus found throughout the environment. 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.

Scopulariopsis (scope-you-lair-ee-op-siss) - This fungus is ubiquitous, and can be found on a wide variety of materials including old carpets and water-damaged wallpaper.  Exposures from Scopulariopsis brevicaulis have been associated with cases of occupational allergy in the to­bacco industry. It can decompose arsenic compounds found on building materials with an ar­senic substrate, such as, some types of wallpaper and paints.

Stachybotrys (stack-ee-bot-ris) - Considerable recent media attention has been focused on the fungi Stachybotrys chartum due to alleged infant deaths in Cleveland from pulmonary hemosiderosis which may be associated with contamination of residences with this fungi. 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, 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 abortogenic in animals and in high doses or chronic low doses it can be lethal. S. chartarum produces other macrocyclic and trichoverroid trichothecenes and, like Memnoniella echinata, produces phenyl-spirodrimanes, which are immunosuppressive. Stachybotrys typically appears as a sooty black fungus occasionally accompanied by a thick mass of white mycelia. 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.

Stemphylium (stem-fill-ee-um) - Reported to be allergenic. Isolated from dead plants and cellulose materials; it can be parasitic or saprophytic.

Syncephalastrum (sin-sef-al-os-trum) - This organism is considered to be primarily non pathogenic in humans and is usually found in soils and in dung.

Taeniolella (tan-o-ee-el-la) - Contaminant.  Little is known concerning allergenic properties or toxicity.  Primarily grows on wood.

Torula (tore-you-law) - Reported to be allergenic. Found as a saprophyte.

Trichoderma (trick-oh-derm-uh) - Trichoderma is most commonly found in soil. Trichoderma 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 sp. is reported to be allergenic but are relatively rare. Inhalation of the conidia or the volatile organic compounds, may cause symptoms similar to those of Stachybotrys reactions.

Ulocladium (you-low-clay-dee-um) - This fungus is reported to be allergenic and considered cosmopolitan. 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 water-damaged building materials. Ulocladium is also found in dust and air samples. Ulocladium is known to be a common airway allergen.

Verticillium (ver-ti-sill-ee-um) - Found in decaying vegetation, on straw, soil and arthropods. A rare cause of corneal infections.

Zygomycetes (zy-go-my-seats) - Large class of genera that include Mucor and Rhizopus.  Some species may cause infections and zygomycosis in compromised individuals, and some species may be major allergens.  The category Zygomycete on reports is a morphological identification when the particular genus cannot be identified.  Particularly on non-cultured samples such as tape-lifts and Air-O-Cell cassettes, many Zygomycete spores are indistinguishable by genus.
 

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