Mycotoxins

Mycotoxins are secondary fungal metabolites that are toxic when consumed by animals and humans. Mycotoxins are not

considered a chemical because they have no molecular features in common; instead, the chemical features are diverse and

include polyketides, terpenes, and indoles. Mycotoxin function has not been clearly established, but they are considered to

play a role in regulating competition with other microorganisms and help parasitic fungi invade host tissues. Mycotoxin

production depends on the fungal species, substrate, temperature, pH, presence of other organisms and other

environmental conditions. The most frequently studied mycotoxins are produced by species of Aspergillus, Fusarium,

Penicillium, Stachybotrys, and Myrothecium, but toxins have been detected from many other fungi under certain growth

conditions. There can be more than one fungal species or genus that can produce the same mycotoxin, and a single

fungal species can produce more than one mycotoxin.

Mycotoxins can accumulate in fungal spores, mycelia, and growth substrates in concentrations dependant on fungal species

and strain. Exposure to mycotoxins occurs when a colonized substrate material is ingested or handled in which skin contact

takes place, or aerosolized spores or mycelial fragments are inhaled. Spore inhalation is considered the most common route

of exposure and can contain significant concentrations of mycotoxins. Mycotoxin exposures have been linked to a variety

of acute and chronic adverse health effects. These effects include symptoms such as pulmonary hemorrhage, dermatitis,

recurring cold or flu-like symptoms, burning/ sore throat, headaches, excessive fatigue and diarrhea, and chronic effects

include carcinogenicity, mutagenicity, teratogenicity, central nervous system effects, immune system damage, and specific

effects of the heart, liver, kidneys, and other organs. Exposures to fungi and mycotoxins are likely to be associated with

exposure to other agents as well.