Fusarium sp

Mitosporic fungus. Hyphomycetes. Teleomorphs (sexual state): Gibberella, Nectria (Ascomycetes).

Characteristics

Distribution

Ubiquitous;
cosmopolitan.
Approx. 50-70 species.

Where Found

Soil, saprophytic or parasitic on plants. Many species are important plant pathogens.

Mode of Dissemination

Wet spore.
Insects, water splash, and wind when dried out.

Growth Indoors

Occasionally found on a variety of substrates. Fusarium requires very wet conditions.
Aw=0.86-0.91 (minimum for various species).

Industrial Uses

Zearalenone has been patented as a growth stimulant in animals and has application as an oral contraceptive, and as an anabolic steroid (<1ppm). F. graminearum is used for the production of quorn, a mycoprotein.

Other Comments

None.

Potential Health Effects

Allergens

Type I allergies (hay fever, asthma).

Potential Opportunist or Pathogen

Causes keratitis, endophthalmitis, onychomycosis, mycetoma, and disseminated infection in immunocompromised patients; infections in burn victims, and systemic opportunistic infections in severely disabled hosts.

Potential Toxin Production

Trichothecenes (type B); T-2 toxin; zearalenone (F-2 toxin), vomitoxin, deoxynivalenol, and fumonisin. Zearalenone is not acutely toxic, and actually may have positive effects with controlled ingestion.

Laboratory Notes

Growth/Culture Characteristics

Grows well on general fungal media. Sporulation in many species requires specialized media. Colonies are shades of pink to orange to purple. Colors are due to both soluble pigments (observed from the reverse) and mycelial pigments.

Spore Trap Recognition

The macroconidia are distinctive and recognizable on spore trap slides. The microconidia are less distinctive and would most probably be identified as "other colorless."

Tape Lift Recognition

Macroconidia are distinctive and often are readily identifiable on tape lifts. However, microconidia of Fusarium (sometimes referred to as an acremonial phase) may be confused with Acremonium.