Poisonous Mushrooms Study Notes

Poisonous Mushrooms

Introduction

  • Two distinct sub-groups of people related to wild mushrooms:

    • Those who love to eat wild mushrooms.

    • Those who would never dream of eating them.

  • Cultural connections:

    • Anglo-Saxon origins: Known as "Kickers".

    • Central/Eastern Europe, Asia: Referred to as "Pickers".

Identification of Mushrooms

  • Main problem: Differentiating between edible and poisonous mushrooms.

    • Individual susceptibility: Reactions can vary between persons.

    • Habitat-induced differences: Environmental factors that may influence toxicity.

Selected Poisoning Outbreaks

  • Source: FDA web page.

    • California (2015-2016): 679 cases of wild mushroom poisoning, 3 cases required liver transplants.

    • Oregon (October 1988): 5 people poisoned by A. phalloides, 2 required liver transplants.

    • New York (1981): Multiple incidents involved Omphalotus olearus and others.

    • British Columbia, Canada (June 1991): 77 cases.

NAMA Mushroom Poisoning Case Registry

  • Started in 1983

    • Total in the US to date: Approximately 4000 cases recorded.

    • 48 states have contributed data.

    • 2000 reported statistics: Only 66 cases nationally, no fatalities.

    • States involved: 18 states, with New York reporting 3 cases.

    • Common problems in New York: Distinguishing Omphalotus (Jack-o'-lantern mushroom) from Cantharellus (chanterelle) and Laetiporus.

European Statistics

  • General trends: While no precise data exists, it is estimated that there are likely thousands of annual cases, with some being fatal.

    • Mass poisonings are much more frequent in Eastern European countries or former Soviet Union states.

    • Countries like France have state-supported identification services to help prevent such incidents.

Types of Mushroom Poisoning

  • Eight different kinds of mushroom poisoning are recognized.

    • Fatalities are primarily associated with Groups I, II, and III.

    • Approximately 50% of all serious mushroom poisonings and 95% of all fatalities are caused by the single genus Amanita.

Group I - Amanitin Poisoning

  • Common species involved: Basidiocarps of Amanita, Galerina, and Lepiota.

    • Most frequently encountered toxic species are Amanita phalloides and Amanita virosa.

  • Identification characters:

    • Universal veil

    • Volva

    • Partial veil

    • Ring

    • Free, white or cream lamellae

    • Spore print: en masse white.

Toxin Molecules

  • Composition: Amino acids formed into double-ring structure known as CYCLIC PEPTIDES.

    • Two types distinguished:

      • Amatoxins (Amanitins): 8 amino acid molecules, 9 different amatoxins identified.

      • Phallotoxins (Phalloidins): 7 amino acid molecules, 7 distinct phallotoxins identified.

    • Research tools: Phalloidin and actin.

Toxicity Data

  • LD50:

    • When injected into mice, phallotoxins are found to be 10 times more lethal than cyanide.

    • LD50 = 2 mg/kg.

    • When taken orally, phallotoxins have no effect due to…

      • Amatoxins are much more toxic when ingested.

      • LD50 = 0.1 mg/kg.

Effects of Amatoxins

  • Mechanism of action:

    • Attack cell nucleus and bind to RNA polymerase II.

    • This enzyme is responsible for transcribing DNA into mRNA.

    • Result: Synthesis of RNA and thus proteins stops leading to cell death.

    • Rapid turnover of cells in the intestine, liver, and kidney makes these organs more vulnerable.

Antidotes and Treatment

  • Current situation: No effective antidote available.

    • Major challenge is related to the latent period of symptoms.

    • Very difficult to treat without confirming presence of amatoxins first.

    • Meixner Test:

      • Method: Squash mushroom tissues on newspaper, dry, add concentrated HCl and observe for color change (blue); high levels of amatoxin induce color change in 1-2 minutes; lower levels may take up to 20 minutes.

Symptoms After Consumption of A. virosa and A. phalloides

  • Four distinct stages of symptoms:

    1. Latent period: 6-24 hours (typically 12 hours).

    2. Violent vomiting, diarrhea, and abdominal pain: Lasting 24 hours.

    3. Brief remission of symptoms.

    4. Collapse of kidney and liver function: Secondary effects on heart and brain leading to coma and death typically within 6-8 days post-consumption.

Treatment Approach

  • Primary actions needed:

    • Remove the toxin from the system using activated charcoal.

    • Utilize haemodialysis to increase the rate of excretion, as toxin levels tend to be higher in urine than in blood.

    • Support systems to maintain electrolyte and fluid balance along with blood sugar levels.

Bastien Treatment Method

  • Developed by Dr. P. Bastien, MD:

    • Procedure consists of administering intravenous 1g vitamin C (twice daily).

    • 2 capsules of nifuroxazide (three times daily).

    • 2 tablets of dihydrostreptomycin (three times daily).

    • Supplement with measures to control fluid and electrolyte balance.

    • Reported success in treating 15 cases of Amanita phalloides poisoning between 1957-1969.

Clinical Outcomes of Bastien Treatment

  • Case studies:

    • In 1974, a person survived after ingesting 65g of A. phalloides.

    • In 1981, another person survived after consuming 70g.

    • This treatment protocol is reportedly used throughout France today.

“Santa Cruz Protocol”

  • Components of the protocol:

    • Milk thistle extract (silibinin).

    • Currently part of a clinical trial with a reputation for being unreliable in food/drink contexts.

    • Reportedly showing promising results so far.

Group II - Gyromitrin Poisoning

  • Associated species:

    • Gyromitra esculenta accounts for about 2-4% of all fatal mushroom poisonings.

    • Toxin precursor is gyromitrin, which hydrolyzes to monomethylhydrazine (MMH), boiling point 87.5°C.

  • Symptoms:

    • Appear after 2-12 hours, typically around 6-8 hours post-consumption.

    • Initial symptoms include a bloated feeling, followed by: nausea, diarrhea, abdominal cramps, faintness, loss of muscle control, fever, jaundice and convulsions, which can lead to coma and death after 2-7 days.

  • Toxicity mechanism:

    • Toxic effects on the central nervous system, gastrointestinal tract, and liver.

    • Treatment: Administering pyridoxine hydrochloride as a specific physiological antagonist.

Group III - Orellanine Poisoning

  • Associated species:

    • Cortinarius orellanus, C. orellanoides, C. rainierensis.

  • Symptoms:

    • Notable incident in Poland (1957): 132 people poisoned, 19 fatalities.

    • Death usually occurs from kidney failure 2-3 weeks after onset of initial symptoms.

    • Latent period of 10-17 days before symptoms arise, which can include intense thirst, burning and dryness of mouth, abdominal pains, nausea, vomiting, culminating in kidney failure with only 100-200g needed to induce complete kidney failure.

Group IV - Coprine Poisoning

  • Associated species:

    • Coprinus atramentarius

  • Toxicity Mechanism:

    • Not toxic unless consumed within 5 days of alcohol; reactions include hot flushes in face/neck, metallic taste, tingling in limbs, throbbing headache, nausea, and vomiting.

  • Mechanism:

    • Coprine (a unique amino acid) blocks the metabolism of ethyl alcohol at the acetaldehyde stage.

    • Effectively, coprine poisoning mimics acetaldehyde poisoning.

    • Antabuse (disulfiram) shares a similar reaction but differs chemically.

Group V - Muscarine Poisoning (PSL Syndrome)

  • Associated species:

    • Clitocybe dealbata, Inocybe geophylla - these mushrooms contain significant amounts of muscarine.

  • Symptoms of PSL:

    • Construction of pupils, blurred vision, muscle spasms, slow heart rate, and drop in blood pressure, which could lead to cardiac arrest.

  • Treatment:

    • Administer atropine intravenously as an antidote.

Group VI - Ibotenic Acid/Muscimol Poisoning

  • Associated species:

    • Amanita muscaria.

  • Symptoms:

    • Include muscle spasms, dizziness, deep sleep, hyperactivity, and altered perception of reality.

Group VII - Psilocybin/Psilocin Poisoning

  • Associated species:

    • Psilocybe, Panaeolus, Conocybe, Gymnopilus contain psychoactive principles that are indole alkaloids: psilocybin and psilocin.

Group VIII - Gastro-Intestinal Irritants

  • Overview:

    • Previous seven types of poisoning are better understood; this group consists of miscellaneous taxa with only common feature being digestive upset within 30-90 minutes of consumption.

  • Symptoms:

    • Most common include vomiting, diarrhea, and abdominal cramps, clearing up spontaneously within 3-4 hours.

    • Little or no information on toxins involved.

  • Associated fungi include:

    • Agaricus, Amanita, Boletus, Chlorophyllum, Entoloma, Hebeloma, Lactarius, Marasmius, Hypholoma, Omphalotus, Pholiota, Russula, Scleroderma, Tricholoma, with occasional fatalities reported across almost all these species.

Summary of Poisoning Patterns

  • Four basic patterns of mushroom poisoning emerge:

    1. Toxins that cause extensive cell destruction with overt symptoms only showing after a delay (e.g., amanitin, orellanine, MMH).

    2. Toxins that cause symptoms immediately upon absorption, or when an appropriate substrate is available (e.g., coprine).

    3. Toxins acting on the central nervous system to cause immediate symptoms (e.g., muscimol, psilocybin).

    4. Undetermined toxins acting in the alimentary canal, often leading to gastrointestinal disturbances.

Warning

  • Key takeaways:

    • Do not take risks when foraging for mushrooms.

    • Always ensure correct identification before consuming.

    • Seek a second opinion if uncertain.

    • Keep voucher specimens in case of poisoning incidents.