More than 90% of human deaths resulting from mushroom poisoning are due to peptide toxins found in Amanita species of mushrooms, such as A. phalloides, A. bisporigera, A. ocreata, and A. virosa. Animals, especially dogs, are frequent victims of poisoning by Amanita mushrooms. Recently, two dogs died after eating toxin containing mushrooms in Michigan in the last few months, See Schneider: Mushroom in backyard kills curious puppy, Lansing State Journal, Sep. 30, 2008 (at lansingstatejournal.com.apps/pbcs.dll/article?AID=/20080930/COLUMNISTS09/809300 321.
High concentrations of peptide toxins are found in the above ground mushroom portion (otherwise known as carpophores or fruiting bodies) of the toxin producing Amanita species. These toxins include two major families of compounds called amatoxins (for example, α-amanitin, FIG. 1A) and phallotoxins (for example, phalloidin, phallacidin, FIG. 1B). Both classes of compounds are bicyclic peptides with a Cys-Trp cross-bridge. In general, amatoxins are 8 amino acids in length while phallotoxins are 7 amino acids in length. Although phallotoxins are toxic when injected, phallotoxins do not survive the human intestinal tract and therefore are usually not responsible for deadly mushroom poisonings in humans and animals. On the other hand, amatoxins do survive cooking and remain intact in the intestinal tract where they are absorbed into the body where large doses irreversibly damage the liver. Liver failure due to poisoning by amatoxins can be “cured” only with a liver transplant (Enjalbert et al., (2002) J. Toxicol. Clin. Toxicol. 40:715; herein incorporated by reference).
There are an estimated 900-1000 species of Amanita, of which the majority do not produce amatoxins or phallotoxins and some are actually safe for humans to eat (Bas, (1969) Persoonia 5:285; Tulloss et al., (2000) Micologico G. Bresadola, 43:13; Weiβ et al., (1998) Can J. Bot. 76:1170; all of which are herein incorporated by reference). Thus mere ingestion of an Amanita mushroom may not herald the need for the extreme medical treatment necessary to save a patient.
Even experienced mycologists may not be able to distinguish edible from poisonous mushrooms even with microscopic examination (EMedicine webmd at hypertext transfer protocol site: emedicine.com/ and hypertext transfer protocol site: emedicine.com/emerg/topic874.htm.
Thus physicians and veterinarians need to be able to directly and quickly confirm whether a patient or an animal showing gastrointestinal symptoms of unknown origin, or who has accidentally eaten an unknown mushroom, is in danger of serious illness or death from eating a deadly poisonous mushroom containing amatoxins.