front

mold spore descriptions

The list of fungi that you are about to read is provided to inform our clients about the fungi that we most often report during the analysis of samples that are sent to us.  It is a list of fungi that we find in both indoor and outdoor samples.  The information given in this section is only a partial list of the most important facts about each fungi, and the facts that our clients will find most useful to them.

That being said, all fungi can be found indoors and outdoors if they are provided with the proper growth conditions.  The growth of a fungus is dependent on variables such as temperature, humidity, and the presence of nutrients. 

acremonium sp.

Acremonium can exist on a wide variety of substrates from carpets and window frames to soil and plants. It is known to be allergenic and can cause Type I allergies (hay fever and asthma) and Type III hypersensitivity pneumonitis.  It has also been associated with Humidifier Lung.  It has been known to produce cephalosporin, a toxin used in to produce cephalosporin antibiotics.

Alternaria can exist on a wide variety of substrates from carpets and window frames to soil and plants. It is known to be allergenic and can cause Type I allergies and Type III hypersensitivity pneumonitis.  It may also cause nasal and subcutaneous lesions and infections in immunocompromised individuals.  Its toxic effects have not been well studied.

Ascospores are frequently found indoors on damp substrates. Ascospores are a very large group of spores that contain many genera and species.  The majority of Ascospores do not cause pathogenic disease, but some examples do exist.  They are known allergens and these effects vary widely between genus and species of each Ascospore.  Toxigenic effects also vary widely within this group.

Aureobasidium sp. can occur on a wide range of substrates where moisture accumulates such as bathrooms, kitchens, shower curtains and window sills.  The allergenic effects seen by these spores include: Type I allergies; Type III hypersensitivity pneumonitis, Humidifier fever, and Sauna Taker’s Lung.  Aureobasidium sp. is commonly considered a contaminant.  It has been implicated as an agent of phaeohyphomycosis.  There have been rare reports of isolates from skin lesions and keratitis in a lymphoma patient.  The toxic effects of this mold are not yet known.

Basidiospores compose a very diverse community of fungal spores. They come in a wide variety of shapes, sizes and colors.  These spores are capable of causing "dry rot" which grows and destroys the structural wood of buildings.  They are common causes of allergenic health effects including: Type I allergies, Type III hypersensitivity pneumonitis, and mushroom culture hypersensitivity.  Opportunistic infections are caused only on rare occasions.  Some Basidiospores have been found to produce toxins, although the effects of these toxins on human health are not well researched.

Botrytis sp. is generally found in or near household plants.  These spores are capable of causing allergenic effects such as Type I allergies, Type III hypersensitivity pneumonitis, and Winegrower's lung.  It has been found to cause pathogenic diseases such keratomycosis on very rare occasions. There are no known cases of human infection. There are no toxins known at this time.

Cercospora sp. is most commonly found as a parasite on higher plants. The health effects of this spore are not well documented or studied.  There has only been one report of human infection caused by Cercospora sp.  This occurred in Indonesia in 1957.

Chaetomium sp. is very commonly found on damp sheetrock and paper or cellulose-containing materials.  The most common allergenic effects are Type I allergies.  This spore is commonly considered a contaminant. It has been occasionally implicated in pathogenic health effects such as systemic and cutaneous phaeohyphomycosis, and it is the rare cause of nail infections.  Chaetomium sp. is capable of producing mutagens and toxins in specific circumstances.  However, the effects of these toxins on human health have not been well researched.

Cladosporium sp. occurs on many substrates including textiles, wood and window sills.  It is also capable of growing on refrigerated foods.  It is the most common outdoor fungus.  Cladosporium sp. is the common cause of allergenic health effects such as Type I allergies and Type III hypersensitivity pneumonitis.  Causes chromoblastomycosis.  This is generally non-pathogenic, but can cause chromoblastomycosis in tropical and sub-tropical climates.  Cladosporium sp. has been found to produce some toxins, however, the effects of these toxins on human health have not been well researched.

Curvularia sp. is capable of occuring on a variety of substrates.  The most common health effects are allergenic and include Type I allergies and allergic fungal sinusitis.  Is an agent of opportunistic infections of the cornea and the sinuses.   It can occasionally cause onychomycosis, ocular keratitis, sinusitis, pneumonia cerebral abscess, and disseminated infection in those patients who are immunocompromised.  No toxins are known at this time.

Drechslera and Bipolaris spores look very similar under a microscope. Therefore, these spores are generally categorized as Drechslera/Bipolaris type spores.  Drechslera and Bipolaris are capable of occurring on a wide variety of substrates.  The most common health effects are allergenic and include Type I allergies.  These spores are the most commonly reported cause of allergic fungal sinusitis.  They can cause infections in the eye, bones, aorta, sinuses, lung, brain and skin and only occasionally causes phaeohypomycosis, including keratitis, sinusitis, and osteomyelitis.  No toxins are known at this time.

Epicoccum sp. is capable of occurring on a variety of substrates that include paper, textiles and insects.  The most common health effects are those that cause allergies such as Type I allergies.  It has not been known to cause infections in humans or animals. 

Fusarium sp. requires very wet conditions, and therefore is found only rarely on a variety of substrates.  It’s capable of causing Type I allergies.  Fusarium sp. is known to be a relatively frequent cause of mycotic eye infections.  It also causes keratitis, onychomycosis, mycetoma, and disseminated infection in immunocompromised patients. Fusarium sp. is capable of producing toxins only under very specific conditions.  It can produce toxins such as Trichothecenes, zearalenone, vomitoxin, and others.

Nigrospora sp. is generally found in decaying plant material and soil.  The most common health effects seen from these spores are allergenic effects displayed as Type I allergies.  There are no known toxins at this time.

The spores of Aspergillus and Penicillium are very hard to distinguish from one another under a microscope. Therefore, they are generally classified as Pen/Asp types.  These spore types are very common and can occur on a wide range of substrates such as cellulose, soil, carpet, paint and food. Water requirements vary widely between species.  Spores belonging to the genus Aspergillus tend to have more serious health effects than those seen by Penicillium sp. spores.  The allergenic effects seen by these spores include: Type I allergies; Type III hypersensitivity pneumonitis and others.  Some species are known to produce potent toxins called aflatoxins.  A. fumigatus causes allergic bronchopulmonary aspergillosis and allergic fungal sinusitis.  Members of this genus cause a disease called Aspergillosis. The disease displays itself in the form of an invasive infection, colonization, toxicoses or allergy. Species within this genus are opportunistic pathogens, and may cause infection in individuals with compromised immune systems.  Penicillium sp. is known to cause keratitis, external ear, respiratory and urinary tract infections.  Severe and invasive diseases are usually associated with immunosuppressed hosts. Many species grow at body temperature.  Many toxins are generated by this genus, however, the effects of these toxins are not well researched at this time.

Pithomyces sp. is found growing on paper or on dead grass.  The allergenic effects of this spore have not been well studied.  It is commonly considered a contaminant, but has not been implicated in human infection. Pithomyces sp. is capable of producing toxins only in very specific circumstances, however, the effects of these toxins are not well known.

Rusts must have living plant material available to them in order to grow. Therefore, Rusts are not found in the indoor environment unless their host plants are present.  They are only found on living plant materials such as grass, flowers, and trees.  The most common health effects seen from these spores are allergenic effects displayed as Type I allergies.  There are no known toxins at this time.

These spores are hard to differentiate from one another under a microscope and are therefore grouped together during identification.  They are generally found on a variety of substrates such as logs, stumps and dead leaves.  The only occasionally occur indoors.  The most common health effects seen from these spores are allergenic effects displayed as Type I allergies.  There are no known toxins at this time.

Stachybotrys sp. is found frequently on wet materials containing cellulose such as wallboard and paper materials.   It commonly produces allergenic health effects such as Type I allergies.  There have been no reports of human infection.  Some species produce a potent toxin that is lethal to animals eating contaminated forage. Inhalation or percutaneous absorption has caused mild symptoms in humans ranging from dermatitis and cough to rhinitis and itching or burning in the oral cavity and nasal passages. Stachybotrys sp. is known to produce toxins, however, the effects of these toxins on human health are still being researched.

Stemphylium sp. rarely grows in the indoor environment. It is responsible for producing Type I allergies.   It is commonly considered a contaminant. There have been rare reports of phaeohyphomycotic sinusitis. There no known toxins for this spore.

Torula sp. is commonly found indoors on cellulose containing materials.  It produces Type I allergies.  There have been no reports of human infection.   Torula sp. is capable of producing toxins in specific circumstances, although the effects of these toxins are not well known at this time.

Trichoderma sp. is found on a wide variety of substrates including paper, wood, and on any cellulose-containing materials.  The most common health effects seen from these spores are allergenic effects displayed as Type I allergies and Type III hypersensitivity pneumonitis.  They are capable of causing pathogenic diseases in immunocompromised persons.  These diseases include perihepatic, peritonitis and pulmonary cavity infections. Trichoderma sp. can produce toxins such as trichothecenes and cyclic peptides that are capable of causing mycotoxicosis in very specific circumstances.

Ulocladium sp. can be found on gypsum, paper, paint, and straw materials.  It requires a large source of water.  The most common health effects are allergenic effects and these are generally displayed in the form of Type I allergies.  It has been implicated in phaeohyphomycosis and in rare subcutaneous tissue infections.  There are no known toxins from this spore at this time.

Zygospores are found on a wide variety of substrates including spoiling food.   They most commonly cause Type I allergies and Type III hypersensitivity.  Zygospores are the principal agent that causes zygomycosis. This generally occurs in patients who are immunocompromised. There are no known toxins caused by zygospores at this time.