Alternaria

Natural Habitat

• Common saprobe and pathogen of plants. Typically found on plant tissue, decaying wood, and foods.
• Soil
• Air outdoors

Suitable Substrates in the Indoor Environment

• Indoors near condensation (window frames, showers)
• House dust (in carpets, and air)

• Also colonizes building supplies, computer disks, cosmetics, leather, optical instruments, paper, sewage, stone monuments, textiles, wood pulp, and jet fuel

Water Activity

• Aw =0.85-0.88

Mode of Dissemination

• Wind

Allergenic Potential

• Type I allergies (hay fever, asthma)
• Type III (hypersensitivity pneumonitis)

Potential Opportunist or Pathogen

• Phaeohyphomycosis {causing cystic granulomas in the skin and subcutaneous tissue}
• In immunocompetent patients, Alternaria colonizes the paranasal sinuses, leading to chronic hypertrophic sinusitis

Industrial Uses

• Biocontrol of weed plants
• Biocontrol fungal plant pathogens

Potential Toxins Produced

• Alternariol (AOH)
• Alternariol monomethylether (AME)
• Tenuazonic acid (TeA)
• Altenuene (ALT)
• Altertoxins (ATX)

Other Comments

• Alternaria
spores are one of the most common and potent indoor and outdoor airborne allergens. Additionally,

sensitization has been determined to be one of the most important factors in the onset of childhood asthma. Synergy with

or

may increase the severity of symptoms