Topic 17 - Mycetism: mushroom poisonings in humans

Question 1

Mycetism

Answer 1

Health hazard caused by ingestion of toxic substances present in macro fungal sporocarps

Question 2

Mycetisms of animals

Answer 2

Little is known

Livestock usually not treated, if poisoned →slaughter

Pets meet rarely with macrofungal sporocarps

Susceptibility of wild animals to fungal poisoning poorly studied

Question 3

Mycetism in humans

Macrofungal poisonings with a long latency period

Answer 3

Phalloides syndrome
Orellanus syndrome
Gyromitra toxicity

Question 4

Mycetism in humans

Macrofungal poisonings with a short latency period (hallucinogenic fungi)

Answer 4

Muscarinic syndrome
Pantherina syndrome
Psilocybin syndrome

Question 5

Other macrofungal poisonings

Answer 5

Disulfiram syndrome
Paxillus syndrome
Gastrointestinal syndrome
Consumption of raw mushrooms

Question 6

Phalloides syndrome: symptoms and poisonous compounds

Answer 6

Latency period: 6-24 hours

Starts with stomach complaints → vomiting and diarrhoea (fever) → high risk of dehydration (gastrointestinal phase)

Acute symptoms end within 1-2 days, but continue with liver damages, liver enlargement, jaundice, haemorrhages in the stomach and intestines, and disturbance of consciousness

Question 7

Toxic compounds of phalloides syndrome

Answer 7

Amatoxins, phallatoxins, virotoxins

Question 8

Death cap poisoning: mechanism of action

Answer 8

Toxins can inactivate the RNA polymerase II enzyme and terminate the protein synthesis at the level of transcription → hepatocytes die

Question 9

Phallotoxins and virotoxins

Answer 9

Less toxic (worse absorption rate in the tissues)

Phallotoxins inhibit cell division and destroy cell membranes

Virotoxins supposed to have effects similar to that of phallotoxins

Question 10

Lethal dose of death cap poisoning

Answer 10

LD50 for humans: 0.1 mg/bwkg

A single sporocarop of 20-25 g of A. phalloides contains 5-8 mg of amatoxins

Question 11

Treatment of death cap poisoning

Answer 11

Removal of toxins from the intestinal tract and the blood must be immediately started after the appearance of the first symtoms → inhibition of liver toxicity → Recovery of electrolyte metabolism of body

Detoxification of blood
Chemotherapy
Transplantation of liver

Question 12

Detoxification of blood

Answer 12

By hemodialysis and plasmaphoresis

Question 13

Chemotherapy

Answer 13

Various liver defences: application of lipoic acid, cytochrome C, silymarin, high dose antibiotics, and vitamin C

Question 14

Taxa causing Orellanus syndrome

Answer 14

Cortinarius orellanus (fool’s webcap)
C. orellanoides
C. rubellus (deadly webcap)
C. splendens (cortinarin)
C. gentilis
C. fluorescens
...

Question 15

Orellanus syndrome symptoms

Answer 15

Long latency (2-17 days), symptoms not always associated with the idea of mushroom poisoning

Repeated mushroom ingestion → toxins accumulated in the tissues

Initial symptoms: anorexia, fatigue, headache, thirst, chills, high fever, GI symptoms

Later symptoms: pain in joints, lumbar region, muscles, kidney damage, and less frequent: liver damage and manifestation of nervous system

Final outcome: kidney faliure, death

Question 16

Cause of orellanus syndrome

Answer 16

Orellanin

• colorless
• Fluoresces in blue
• has bipyridyl structure
• has been detected from the renal tubules, highly probable to affect them

Question 17

Treatment of orellanus syndrome

Answer 17

Symptomatic treatment of kidneys
Dialysis
Transplatnation of kidneys

Question 18

Prevention of orellanus syndrome

Answer 18

little is knownabout the toxins of Cortinarius species hence, the consumption of all the related taxa should be avoided

Question 19

Taxa causing Gyromitra toxicity

Answer 19

Gyromitra esculenta(false morel)
G. fastigiata(brown false morel)
G. gigas(snow morel)
G. infula (hooded false morel)
Cudonia circinans
Helvellaspp. (elfin saddles)
Discinaspp.

Question 20

Gyromitra toxicity symptoms

Answer 20

Two-phase course
Long latency period
Starts with GI symptoms (nausea, abdominal pain, vomiting, diarrhoea, headache)
May lead to liver damages and nervous system symptoms (nervousness, excitement, delirium)

2-3 days → circulation system of the patient may collapse; death is often due to respiratory failure

Question 21

Gyromitrin: mechanism of action

Answer 21

Thermo-instable compound

Serious poisoning may happen only when large amounts of raw mushrooms are ingested

Liver → transformed into monomethyl hydrazine

Inhibit enzymes; are teratogenic, mutagenic and carcinogenic effects have also been shown

Question 22

Treatment of gyromitra toxicity

Answer 22

Similar to death cap poisoning

vitamin B used to support liver

Question 23

Muscarinic syndrome - muscarine mechanism of action

Answer 23

Muscarine → structural analog of acetylcholine: able to bind to all types of muscarinic acetylcholine receptors and activate them

Parasympathetic nervous system uses chiefly acetylcholine as its neurotransmitter → muscarine causes parasympathetic predominance

Question 24

Symptoms of muscarinic syndrome

Answer 24

Short latency period

Characteristic parasympathetic neurological symptoms (perspiration, salivation, lacrimation) can be observed with a low heart rate and blood pressure, and narrowpupils

Other symptoms: shortness of breath, visual disturbances

Question 25

Treatment of muscarinic syndrome

Answer 25

The antidote of muscarine is atropine (it causes sympathetic predominance) (injection)

Question 26

Pantherina syndrome symptoms

Answer 26

Short latency period Symptoms similar to alcohol intoxication Personality disorders, time and space perception disorders, increased emotional state, fiery speech, strong motor restlessness Stuporous, fall deep asleep → wake up without any adverse effects

Question 27

Pantherina toxins

Answer 27

Symptoms mainly caused by isotonic acid, present in large amounts in A. pantherina, can be transformed into muscimol or muscason

Question 28

Muscimol

Answer 28

Structural analog of neurotransmitter gamma-aminobutyric acid (GABA), which is a general inhibitory neurotransmitter in the CNS Have insecticidal effects Symptomatic treatments applied

Question 29

Psilocybin syndrome symptoms

Answer 29

Latency period: from 30 minutes to 2 hours Physical symptoms: headache, dizziness, disturbance of consciousness, numbness, slow pulse, low blood pressure Psychic symptoms: happiness, fear, feeling of liberation, time and space perception disorders, depression, tantrum, delirium Effects may take 6 to 10 hours

Question 30

Psilocybin syndrome: toxins

Answer 30

Neurotoxins, antagonists of serotonin: psilocybin, psilocin, beocystin,bufotenin Psilocybinforms acolor-less crystal, structurallysimilar to lysergic acid Blue compounds are pro-duced when psilocybin is oxidized → fungi with bluesporocarps are often hallucinogenic Active ingredients of psychotherapeutic drugs

Question 31

Disulfiram syndrome symptoms

Answer 31

The related fungal species are not poisonous Symptoms occur only after drinking alcohol: feeling hot, face flushed, sweating, trembling, elevated heart rate, blood pressure drop, characteristic metallic taste in the mouth, fainting, symptoms disappear after a few hours

Question 32

Disulfiram syndrome toxins

Answer 32

The active constituent iscoprine, aninhibitorof acetaldehyde dehydrogenase enzyme In the body,coprineis transformed into aminocyclopropanol; it inhibits the conversion of alcohol to acetaldehyde then to acetate ion; symptoms occur due to the temporary increase of acetaldehyde

Question 33

Disulfiram syndrome treatment

Answer 33

does not require special therapy After eating these fungi → no alcohol for 3 days

Question 34

Pauxillus syndrome symptoms

Answer 34

1-2 hours after the ingestion of raw sporocarps, gastro-intestinal symptoms (vomiting, diarrhea) occur for everybody; no symptoms when cooked

Question 35

Consumed repeatedly

Answer 35

the cooked sporocarps can also cause serious sepsis in the susceptible persons; Symptoms: bloody urine, urinary retention, pain in the kidneys, death (in severe cases)

Question 36

Pauxillus syndrome - course

Answer 36

The number of antibodies produced against the fungal proteins increases antigen-antibody → complexes are developed that cause agglutination of red blood cells → hemolysis (immunohemolytic anemia) Blood hemoglobin content decreases dramatically; sometimes the sensitivity is developedafteryears of repeated ingestionsof P. involutus

Question 37

Pauxillus syndrome - treatment

Answer 37

Symptomatic treatments: gastric lavage, laxation, support of blood circulation Transfusion of blood In case of renal failure: dialysisis applied

Question 38

Gastrointestinal syndrome - symptoms

Answer 38

Mild symptoms occur in 15 minutes to 2 hours Vomiting, diarrhea, nausea, abdominal cramps, but muscle crampsand circulation disorders can also occure

Question 39

Gastrointestinal syndrome toxins

Answer 39

chemically different compounds with an unpleasant odour, or a pungent taste (e.g.: terpenes, sesquiterpenes, anthraquinones) irritating the stomach and the intestines

Question 40

Gastrointestinal syndrome treatment

Answer 40

recovery of electrolyte metabolism