Laboratory Excellence Since 1987

Microbiology Department

Reference Photos

  • Acremonium

    Commonly found in soil and dead plant materials. This mold also grows on wet building materials, such as drywall, ceiling tiles, and building paper. It has been reported as an allergen. Some isolates are known to produce toxins in the tricothecene group. Symptoms of toxin exposure include: nausea, vomiting, and diarrhea. Acremonium may also be pathogenic in immunocompromised individuals, causing mycotic keratitis, rarely mycetoma (subcutaneous lesions), lesions of the hard palate of the mouth, meningitis, arthritis, and systemic disease.

  • Alternaria

    Commonly found in outdoor air, this organism grows on decaying wood, on many kinds of plants, foodstuffs, soil, and compost. It may be a contaminant of water-damaged building materials containing cellulose. This is one of the most important fungal allergens. Alternaria may produce toxic metabolites that may be harmful to humans. Pathogenic infections are infrequent, but may include: upper respiratory tract (nasal septum infections), mycotic keratitis, skin infections, and osteomyelitis (inflammation of bone, especially bone marrow).

  • Arthrinium

    Commonly found on plant materials, especially grasses. Not reported to be a human pathogen.

  • Ascomycetes

    The largest group of fungi, also known as "cup fungi". Most often associated with terrestrial habitats, some may inhabit freshwater or marine habitats. This group includes a wide variety of organisms that may cause allergic reactions or opportunistic infections. Some members of this group may also produce toxins that are harmful to humans. Some, such as Chaetomium, are associated with water-damaged building materials.

  • Aspergillus

    Commonly found in the outdoor environment; however, the frequency is generally low. Found in soil, compost, plant debris (decaying vegetation), or stored grain. It may also be found on water damaged building materials. Aspergillus may cause allergic reactions and hypersensitivity pneumonitis. Some species of Aspergillus may cause opportunistic infections; therefore, may be a serious concern in hospital settings. Many species produce toxins. Toxin production may be dependent upon the species or strain within a species, as well as the food source of the fungus. Some of these toxins are carcinogenic.

  • Aureobasidium

    This is a yeast-like fungus. It is commonly found on caulk or damp window frames in bathrooms. It may also be found in conjunction with Cladosporium sp. growing on siding. Growth usually begins with a pink color turning to black with age. Although infection is rare, this organism may be allergenic.

  • Basidiomycetes

    This is a broad group including mushrooms, toadstools, puffballs, rusts, and smuts. These organisms are often associated with dry rot. High levels in an indoor environment can contribute to allergies. Poria incrassata is a particularly destructive basidiomycete. It has resulted in the collapse of severely infested buildings.

  • Bipolaris

    Found in soil and plant debris, this organism may be parasitic to plants. Bipolaris may be a cause of allergic sinusitis or phaeohyphomycosis (subcutaneous abscesses).

  • Botrytis

    Associated with plants, it may be parasitic on plants and soft fruits. High levels are found in greenhouses or other indoor areas with high humidity and large numbers of plants. Indoor exposure can cause allergic asthma.

  • Chaetomium

    Commonly found on deteriorating plant materials, especially wood products and frequently found on water-damaged drywall. It is associated with the decomposition of cellulose-made materials. This organism emits a strong musty odor. Chaetomium is reported to be allergenic and occasionally may cause systemic or cutaneous phaeohyphomycosis. Some rare compounds produced by this organism have on occasion been identified as mutagenic.

  • Chrysosporium

    A common saprophyte found in soil, dung, plant debris, and seeds. Some species are occasionally associated with infections of the skin and nails. Microscopically, the organism may resemble some dermatophytes and some strains may resemble Histoplasma sp. and Blastomyces sp.

  • Cladosporium

    This genera is the most frequent encountered in both outdoor and indoor air. Found in soil and plant litter, it is often found in elevated levels in water-damaged environments. Homes with poor ventilation or damp conditions may see high concentrations. It may be found in refrigerator drip pans and the bottom of refrigerators, on moist window frames, and on moist painted surfaces, or in high humidity locations. Cladosporium may cause discoloration of interior paint, paper, and textiles.

  • Curvularia

    This organism is saprophytic and may be parasitic on tropical and subtropical plants. It is reported to be allergenic. Curvularia rarely causes infections including: mycotic keratitis, mycetoma, and opportunistic infections in immunocompromised individuals.

  • Drechslera

    This organism is similar to Bipolaris sp. It most frequently causes mycotic keratitis, but also nasal infections, allergies, phaeohyphomycosis, peritonitis have been reported.

  • Epicoccum

    This is a saprophytic organism found in soil, on plants, grains, textiles, and paper products. It is a common secondary invader of plant materials (associated with Aureobasidium sp. and Cladosporium sp.). It may be isolated from water-damaged building materials; although, it is typically considered an outdoor organism. Epicoccum is reported as an allergen. It's ability to grow at higher temperatures makes it a potential skin pathogen.

  • Fusarium

    Worldwide distribution associated with soil, plants, and grains. It may be pathogenic to plants, causing root and stem rot, vascular wilt, or fruit rot. It is often found in extremely wet conditions, such as humidifiers. Fusarium may affect water-damaged carpets and a variety of other building materials. Spores are typically slimy and may be difficult to isolate in air samples. It is an important mycotoxin producer and causes worsening of allergies and asthma symptoms. Fusarium is known as the most common cause of mycotic keratitis. It is also isolated from skin lesions of burn patients, nail infections, ear infections, varicose ulcers, mycetoma, osteomyelitis in trauma patients, and disseminated infection, especially in immunocompromised patients.

  • Memnoniella

    Worldwide distribution, mainly found in soils in tropical regions. May be isolated from cellulose containing materials, textiles, and dead plant materials. This organism is closely related to Stachybotrys chartarum. It produces toxins similar to those of Stachybotrys that are potentially dangerous in an indoor air environment. Exposure to this organism should be avoided.

  • Mucor

    Worldwide distribution, found in soil, moist hay, dung, fruits, leather, meat, dairy, and stored food products. Mucor is frequently present in air samples and almost always found in house dust. It may also be isolated from dust in HVAC systems and poorly maintained carpeting. It may be allergenic and may cause infections, especially in the immunocompromised.

  • Nigrospora

    Exists as a parasite or saprophyte on plants. It has been reported as an allergen and a cause of mycotic keratitis.

  • Paecilomyces

    A saprophyte found in dead plants, compost, soil, and dust. This organism is heat tolerant; therefore, is found in warm and arid regions. It is known to cause spoilage of foods and can infest juices undergoing pasteurization processes. Some species are resistant to preservatives used in food production. It may attack materials including: PVC, photographic paper, timber, optical lenses, and leather. Generally, is an opportunistic pathogen causing humidifier disease and allergic alveolitis.

  • Penicillium

    Commonly found in soil, food, cellulose paint, grains, compost, carpet, wallpaper, and interior fiberglass duct insulation. It may cause spoilage of food and may colonize leather materials. Penicillium is one of the first organisms to grow on water-damaged materials; therefore, it is considered an indicator organism for dampness indoors. This is a very large genus including a large number of organisms. This makes identification to the species level extremely difficult. It is known to cause allergic reactions and hypersensitivity pneumonitis. Some species are known mycotoxin producers. The health of occupants may be adversely affected in an indoor environment that has amplification of Penicillium sp.

  • Pithomyces

    Found on decaying wood, soil, and plant material. It has been found growing on paper products, but is not common indoors. Pithomyces is a possible mycotoxin producer, but is not known to cause human infections.

  • Scopulariopsis

    Found in house dust, old carpeting, fruits and nuts, and other materials. This organism is able to decompose arsenic compounds. It may grow on wallpaper containing paris green, producing arsine gas. Anti-static compounds containing arsenic are used in some wall-to-wall carpeting, which may result in high concentrations of Scopulariopsis. It may cause infections of the skin and nails.

  • Stachybotrys

    Grows well on extremely wet building materials containing cellulose, such as sheetrock, paper, ceiling tiles, cellulose containing insulation backing, and wallpaper. It produces mycotoxins that are extremely toxic. These toxins may irritate the skin and mucous membranes. Exposure is through inhalation, ingestion, or dermal exposure. Symptoms of toxin exposure include: dermatitis, cough, rhinitis, nosebleeds, burning sensations in the mouth and nasal passages, cold and flu-like symptoms, headache, general malaise, and fever. Air samples may not accurately indicate amplification of Stachybotrys due to the organism producing "sticky" spores that may not aerosolize without disturbance of infested materials. Bulk or surface sampling of suspect material is recommended. Extreme care should be taken when this organism is present in an indoor environment.

  • Stemphylium

    Found on dead plant and cellulose materials. It may be saprophytic or parasitic on plants. The organism has been reported as an allergen.

  • Trichoderma

    One of the most widespread soil fungi, it colonizes decaying leaves, timber, and compost. Often found in damp houses on paper products, carpet, and unglazed ceramics. Trichoderma has a strong cellulytic activity; therefore, wood construction can be very affected by this organism. Reported as an allergen, some species also produce metabolites related to tricothecene, which can be toxic. These substances cause symptoms similar to those associated with Stachybotrys. It may also be the cause of opportunistic infections in immunocompromised individuals.

  • Ulocladium

    A saprophyte, found in soil, on wood, and decaying plant materials. The organism has a high water requirement, making it an excellent indicator of water damage. It grows well on wet wallboard and particle board. Ulocladium can be very allergenic, contributing to allergy load especially in those with sensitivity to Alternaria.