Aureobasidium sp
Mitosporic fungus. Hyphomycetes.
Characteristics
Distribution
Ubiquitous;
cosmopolitan.
Approx. 15 species.
Where Found
Soil, forest soils, fresh water, aerial portion of plants, fruit, marine estuary sediments, wood.
Mode of Dissemination
Wet spore.
Wind (when dried out), water droplet.
Growth Indoors
Widespread, where moisture accumulates, especially bathrooms and kitchens, on shower curtains, tile grout, window sills, textiles, liquid waste materials.
Industrial Uses
Used in the removal of unwanted components of raw textile materials. Aureobasidium pullulans produces pullulan (a biodegradable polysaccharide) used for packaging of food and drugs. It is processed into fibers which have a shiny gloss like rayon and have the strength of nylon.
Other Comments
Aureobasidium pullulans represents a morphologically heterogenous group of taxonomically related fungi. Very closely related to Hormonema. Older medical texts refer to this fungus by its former name Pullularia pullulans.
Potential Health Effects
Allergens
Common.
Type I allergies (hay fever, asthma).
Type III hypersensitivity pneumonitis: Humidifier fever, Sauna taker's lung.
Potential Opportunist or Pathogen
Rare reports of isolates from skin lesions, keratitis, spleen abscess in a lymphoma patient, blood isolate from a leukemic patient.
Potential Toxin Production
Not known.
Laboratory Notes
Growth/Culture Characterisics
Grows well on general fungal media. Yeast-like, beginning cream to pink, becoming dark brown with age.
Spore Trap Recognition
The identification of A. pullulans without culture is difficult because of the variety of morphologic forms it takes. Generally, we report irregular clumps of dark brown mycelia dividing in more than one plane as Aureobasidium pullulans. Vegetative hyphae from other unrelated dematiaceous fungi, especially those which form chlamydospore-like structures may be indistinguishable from Aureobasidium.
Tape Lift Recognition
The morphology of Aureobasidium is distinctive (in a broad sense) and is identifiable if enough structures have been lifted by tape. (A. pullulans is a yeast-like organism which, when it is moist, may not lift well on tape.)