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Ashes to ashes, Dust to dust,
Rot and rust will harm all of us
DANGERS OF
MYCOTOXIN A very Brief Introduction
HADI AKBAR BIN DAHLAN VISUAL INTERPRETER [email protected]
http://easysciencenote.blogspot.com
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INTRODUCTION
Toxin that originate from fungi are termed Mycotoxin. Most of the fungi that produce these
were filamentous fungi; where the intoxication is by digestion. Some of the effects are:
Decreased Growth rate
Abnormal reproduction
Diseases
Early death (for animal)
A bread covered by mold. (left)
The structure of the filamentous mold on the bread (down)
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Ergotism
The case of ergotism toxication is due to
contamination of Claviceps Purpurea on
grain. The fungus proliferates throughout
the grain untill a “tumorous mass” called
sclerotium forms. The mass withholds the
resting stage of the fungus that dormant in
dry condition and germinate when
moistened.
There are 2 symptoms of ergotism:
Gangrenous ergot poisoning
Characterized by severe pain,
inflammation, and a burned appearance
of the extremities, which may become
blackened. In severe cases, loss of
fingers, toes, and even hands and feet can
occur.
Gangrenous ergot poisoning cause
constriction of blood vessels. This is due
to vasoconstriction in peripheral veins
and arteries. The fungus contains
ergotamine; an alkaloid compound
whose structure is almost similar to
neurotransmitter. This meant that
ergotamine can bind to cell receptor and
affect signal transduction in the cell.
Convulsive ergot poisoning
The symptoms are primarily neurological
in nature and include writhing, tremors,
numbness, blindness, convulsions, and
hallucinations. No physical features such
as inflammation appear.
Convulsive ergot poisoning was less
understood, and it is said to be caused by
psychoactive alkaloids. It is said that it
have the same effect as Lysergic acied
Diethyl (LSD).
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Alimentary Toxic Aleukia (ATA)
This mycotoxicoses is also knows as septic angina. The fungi most associated with ATA is genus
Fusarium. Most of the ATA outbreaks are due to population consumption of overwintered harvest of grain. Therefore, this outbreaks occurs in Russia and europe back in the spring of early half of the 20
th
Century.. This because cryophilic fungi because have a peculiar capability of producing toxic substances
in increased amounts when grown under conditions that include a period of growth at temperatures near 0’C. Investigators found that field conditions that included relatively high winter temperatures, deep snow
cover, frequent freezing and thawing were conductive for fungal growth as well as toxin production in
crops.
There are 4 stages of ATA:
Stage 1: Shortly after exposure to the toxins,
victims experience:
burning sensations in the mouth, throat,
esophagus, and stomach.
Diarrhea
abdominal pain due to inflammation of the
gastric and intestinal mucosa.
Reduce Leukocyte count
tachycardia
Stage 2: This stage start with reduction in intensity
of the symptoms. Although the victim may begin to
feel well and capable of normal activity, but:
The destruction of the bone marrow continues
with a further reduction of leukocyte
The body’s resistance to infection is reduced.
If the consumption of the contaminated food is discontinued at this time and the victim obtains
medical care, the chances of recovery are good.
Stage 3: This stage is signaled by the appearance of:
hemorrhages on the skin and on the
mucous membranes of the mouth and
tongue
necrotic lesions proliferate along with an
increased tendency for infection.
Esophageal lesions often occur and the
involvement of the epiglottis may cause
laryngeal edema leading in many cases to strangulation.
Stage 4: If the Stage 3 patient receives acute
medical treatment including blood transfusions and
heavy dose antibiotic treatment, he may survive the ordeal and thus enter Stage 4, the period of
convalescence. This period requires several months
of treatment for the nearly full recovery of the
hematopoietic system.
The toxin of genus Fusarium is called T-2 Toxin. These toxin inhibit protein synthesis by binding to
ribosomes; which activates stress kinase, inhibit DNA synthesis and mitochondrial function. T-2 toxin most strongly affects actively dividing cells such as those lining the gastrointestinal tract, skin, lymphoid,
and erythroid cells. Immunosuppression is a further major effect of inhibition of protein synthesis that is
caused by a decrease in antibody levels, in immunoglobulins, and in certain other humoral factors such as cytokines.
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Kashin-Beck Disease
This diseases is a disorder of the bones and joints of the hands and fingers, elbows, knees, and ankles of children and adolescents who
slowly develop stiff deformed joints, shortened limb length, and short
stature due to necrosis of the growth plates of bones and of joint
cartilage.
This disease is a multifactorial disease; Selenium deficiency with
consumption of fungal contamination of barley grains by Alternaria sp., Trichotecium sp., Cladosporium sp., Fusarium sp. and
Drechslera sp. Studies indicated that the metabolite vomitoxin
secreted by the fungal is the causative agent for this disease.
Patulin
Patulin is a fungal metabolite that is secreted by many Penicillium species. Exposure generally results from consumption of moldy fruits
and fruit products. Although patulin has been reported to produce
toxic effects in cattle and poultry and has been shown to be a mutagen, a weak carcinogen, and a teratogen in experimental systems,
a negative impact on human health has not been established.
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Zearalenone
a potent estrogenic substance that is produced by the fungus
Fusarium roseum and its sexual stage, Gibberella zeae, and
some related fungi. Consumption of corn infected with these
fungi can cause a loss of reproductive capacity and other
estrogenic effects in pigs and other domestic animals.
Symptoms of zearalenone poisoning in young pigs include
swelling and eversion of the vagina until, in some cases, the
cervix is visible. Recent studies have implicated this toxin in
the cause of precocious puberty in a group of girls.
Amanita Phalloides
Also known as Death cap mushroom, is mushroom that contains 2 types of substances;
phalloidins and amanitins. Of the 2, amanitin is much more toxic
in which it exhibit LD50 in rodents in range of only 0.1mg/kg,
regardless or intravenous or oral route. Amanitins target RNA
polymerase II; which can inhibit ribosome production, making
protein synthesis impossible.
The effects of A. phalloides poisoning may occur many hours
following consumption of the mushroom. The initial signs of
toxicity are:
Abdominal pain, diarrhea, and vomiting.
Within three to five days following exposure to the toxins,
failure of liver and kidneys occur
The chemical structures of the amanitins and the
phalloidins are complexes of cyclic peptides that contain
seven or eight amino acids. Although these cyclic
peptides are responsible for the toxic effects of the
mushroom, they exist in combination with polysaccharide
components as large molecular weight complexes called
myriamanins.
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REFERENCE
Takayuki Shibamoto and Leonard F. Bjeldanes, 2009, Introduction to Food toxicology (2nd
Edition), Chp. 7: Toxins from fungi, pg. 159 – 180, Academic Press, London.
Katherine Scurrah, 2010, Make it safe: A guide to food safety, Chp. 2 Food Safety Hazards pg
21-30, CSIRO Publishing, Collingwood.