Characteristics

Distribution
Ubiquitous;
cosmopolitan.
Some species are more commonly found in tropical or subtropical areas.
Drechslera: Approx. 20 species.
Bipolaris: Approx. 20 species.
Exserohilum: Approx. 8 species.

Where Found
Plant debris, soil. Plant pathogens of numerous plants, particularly grasses.

Mode of Dissemination
Dry spore.
Wind.

Growth Indoors
Yes, on a variety of substrates.

Industrial Uses
Not known.

Other Comments
None.

Potential Health Effects

Allergens
Common.
Type I allergies (hay fever, asthma).
Other: Most commonly reported cause of allergic fungal sinusitis.

Potential Opportunist or Pathogen
Occasionally a cause of phaeohyphomycosis, including keratitis, sinusitis, and osteomyelitis. These infections most often occur in immunocompromised persons, although infections also occur in normal hosts. One case of brain abscess reported in an immunocompromised patient.

Potential Toxin Production
Not known.

Laboratory Notes

Growth/Culture Characteristics
Grows well on general fungal media although many isolates need "light/dark cycling" for sporulation. Colonies are shades of dark gray to brown.

Spore Trap Recognition
Group includes Drechslera, Bipolaris, Exserohilum and the rare Helminthosporium. Members of this group can best be differentiated in culture.

Tape Lift Recognition
This group is readily identifiable on tape lifts.