POISONOUS FUNGI AND MYCOTOXINS Flashcards
Mycoses vs Mycotoxicosis
Mycoses caused by frank growth of fungi on animal hosts
Mycotoxicosis is caused by exposure to fungal toxins
Examples of poisonous fungi
Claviceps purpurea- ergot
Amanita virosa- european destroying angel
Galerina marginata- autumn skullcap
Inocybe erubescens- red-staining inocybe
Trogia venenata- little white
Effects of chronic exposure to mycotoxins
Cancer
Kidney toxicity
Immune suppression
Source of aflatoxins
Aspergillus flavus and Aspergillus parasiticus
The major examples of aflatoxins
B1, B2, G1, G2
What is the most potent natural carcinogen
Aflatoxin B1
Major aflatoxin produced by toxigenic strains
Aflatoxin B1
Effects of acute aflatoxicosis
Death
Effect of chronic aflatoxicosis
Cancer
Immune suppression
Effect of aflatoxins on reproduction
Decreases testicular development
increases testicular degeneration
decreses plasma testosterone concentration
impairment of leydig cell function
decreases percentage of live sperm
increases sperm abnormalities
causes morphorlogical repressive changes in testis
decreases reproductive potential
Cause of ergotism
Ergot alkaloids from Claviceps purpura
effects of ergotism in humans
Gangrene and convulsions
Most abundant fumonisin
Fumonisin B1
Which organisms produce fumonisins
Fusarium species
Fusarium proliferatum
Fusarium nygamai
Fusarium verticillioides
and
Alternaria alternata
Effect of fusarium on foetus
Neural tube defects
Which metabolic pathway does fumonisins interfere with
Sphingolipdi metabolism
Which enzyme does fumonisins inhibit
Ceramide synthase
Which organism was patulin isolated from
Penicillium patulum
Mechanism of action of patulin
Induces DNA-DNA cross links
Direct and indirect reactivity to DNA
What type of metabolites are trithothecenes
Sesquiterpeneoids
Fungal genera that produce thrithothecenes
Fusarium
Myrothecium
Phomopsis
Stachybotrys
Trichoderma
Trithothecium
Which mycotoxin is an enxtremely potent inhibitor or eukaryotic protein synthesis
trithothecenes
Which mycotoxin causes alimetary toxic aleukia
Diacetoxyscirpenol
Symptoms of alimentary toxic aleukia
Inflammation of skin
vomiting
damage to hematopoietic tissues
necrosis in oral cavity bleeding from mouth, nose, vagina
CNS disorders
What type of mycotoxin is diacetoxyscirpenol
Trithothecene
MOA of trithothecenes
Modulates serotonin activity
attenuate or potentiate expression f cytokines at low concentrations
bind to eukaryotic ribosomes and inhibit protein synthesis
How do trithothecenes cause emesis
Modulates serotonin activity
which cancer is caused by zearalenone
Human cervical cancer
Which mycotoxin is implicated in premature thelarche
Zearalenone
Which receptors does zearalenone bind to
Estrogen receptors
MOA of zearalenone
DNA damaging effect
Polyploidy of cells
Sister chromatid exchange
Chromosomal aberration invitro
Which fungi produce citreoviridin
Aspergilli
Penicillia
Which disease is caused by Citreoviridin
Shoshin kakke
Symptoms of shoshin kakke
Palpitations
Difficulty breathing
Rapid pulse
Nausea
Vomiting
Hypotension
restlessness
Violent mania
Respiratory failure
Death
Which mycotoxins can act immediately on contact
Thiothecenes
Clinical effect of ochratoxin A
Kidney disease ( focal segmental glomerulosclerosis)
effect of muscarine
autonomic nervous system effects
In which country did the disease shoshin kakke occur
Japan and other Asian countries
