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MYCOTOXICOSES Prabin Shah BScMLT, MSc(Biochemistry)
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Mycotoxicoses

Aug 16, 2015

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Page 1: Mycotoxicoses

MYCOTOXICOSES

Prabin Shah BScMLT, MSc(Biochemistry)

Page 2: Mycotoxicoses

DEFINITION

Mycotoxicoses is defined as an illness of man or animal due to ingestion of pre-formed substances produced by the action of certain molds or filamentous fungi on particular food-stuff.

Page 3: Mycotoxicoses

MYCOTOXINS

Secondary metabolites produced by food-borne filamentous fungiVary in their severity :Carcinogen/allergenNon-volatile & low molecular weightSome are lethalCause identifiable diseasesWeaken the immune system without producing symptoms

Page 4: Mycotoxicoses

FACTORS DEPENDS ON PRODUCTION

Temperature (4-32˚C)

Moisture (22-23% in grain)

Aeration (1-2% of O₂)

Relative humidity (>70%)

Substance on which the fungus is growing

Page 5: Mycotoxicoses

Acute: Rapid onset from single exposure Chronic: Delayed onset from multiple long term exposure

Mutagenic: Causing damage to DNA

Teratogenic: Causing birth defects

TOXICITY

4 TYPES:

Page 6: Mycotoxicoses

Respiratory problems

Reproductive problems

Liver, kidney or other organ damage

Cancer

Death

MYCOTOXIN CAN CAUSE:

Page 8: Mycotoxicoses

SIGNIFICANT FUNGI

Most of the significant fungi producing mycotoxicoses mainly belong to toxigenic species of 3 genera:

Aspergillus Fusarium Pencillium

Page 9: Mycotoxicoses

MEDICALLY SIGNIFICANT MYCOTOXINS

1.Aflatoxins

2.Fumonisins

3.Trichothecenes

4.Ochratoxins

5.Cyclopiazonic Acid

6.Zearalenone

7.Patulin

Page 10: Mycotoxicoses

MYCOTOXINS

FUNGAL SPECIES

SOURCE OF EXPOSURE

CLINICAL CONDITIONS

Aflatoxins A.flavus,parasiticus,nomium,P.puberulum

Nuts,Maize Aflatoxicosis, Rey’sSyndrome

Fumonisins Fusarium moniliforme Maize ELEM,PPE

Trichothecens

Fusarium graminearum,F.sporotrichioides

Maize,Sorghum

HumanToxicosis,

Ochratoxins A.ochraceus,A.niger, P.verrucosum

Cereals,coffee-Beans,Bread

Nephropathies

Cyclopiazonic Acid

A.flavus,A.versicolor,A.oryzae,P.cyclopium

Groundnut,Corn,Meat

Co-contaminant,Kodua Poisoning

Zearalenones

Patulin

F.Graminearum

P.patulum/griseofulvum

Wheat,Maize,Barley,SorghumThought to be the antiviral antibiotic.

Genital disorders in animals ie, Pigs

Page 11: Mycotoxicoses

AFLATOXINS(Aflatoxicosis)These toxins were discovered as a cause of mysterious disease termed as Turkey-X-disease during 1960s in England.Killed approx.1,00,000 birds and ruined turkey industry. Aflatoxins most commonly produced by A.flavus are B1 and B2.A.parasiticus produces G1and G2.

These are designated as B & G on the basis of their metabolites which exhibits blue(B) and green(G) fluorescence under U.V. light on TLC plates.

Page 12: Mycotoxicoses

Aflatoxin B1 is the most important biologically active mycotoxin because of its common occurrence in food items and is highly toxic and carcinogenic.

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AFLATOXIN TAINTED PRODUCTS

Page 14: Mycotoxicoses

Poisoning that results from ingesting aflatoxins

2 forms:

Acute severe intoxication: Result in severe liver damage,And subsequent illness or death.

Chronic subsymptomatic aflatoxicosis: signs and symptoms are lethargy,anorexia and muscle weakness followed by spasm.

AFLATOXICOSIS

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Reye’s syndrome: It is an acute aflatoxicosis in which patient presents with signs and symptoms of encephalopathy and fatty degeneration of viscera.This is an endemic disease of children in developing countries.

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Reye’s syndrome

Fatty degeneration of liver

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Aflatoxin Detection

Black Light test - BYG fluorescence

ELISA

Chromatography (HPLC)

Rapid immunochromatographic method

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AFLATOXIN GROWING ON CORN IS DETECTED BY BLACK LIGHT TEST

Page 19: Mycotoxicoses

FUMONOSINSSecondary metabolites produced by various species of fusarium.They are toxic and carcinogenicCommon contaminants of maize ,corn and their products.Cause fatal illness in animals like equine leukoencephalomalacia(ELEM)fatal disease in horses,Porcine pulmonary edema(PPE) in pigs,and hepatotoxic and carcinogenic effects in rats.

Page 21: Mycotoxicoses

OCHRATOXINSNaturally occuring mycotoxin and is produced by various species of Aspergillus and pencillium.Originally isolated from Aspergillus ochraceous hence named ochratoxin.Out of many ochratoxins,ochratoxin A is medically significant.Natural occurrence of these toxins in grains and other plant products.

Page 22: Mycotoxicoses

Human exposure to ochratoxin

Direct – consumption of contaminated plant foodIndirect – consumption of animal tissues exposed to contaminated materials.It produces fatal renal disease called as endemic nephropathy and urinary tract tumors.

Page 23: Mycotoxicoses

TRICHOTHECENE

Produced by Fusarium species.

Most significant effect of these toxin is the depression of immune system in both human as well as animals.

Were implicated in biological warfare and putative incident of ‘yellow rain’ in Laos.

Page 24: Mycotoxicoses

CYCLOPIAZONIC ACID

Produced by genous Aspergillus and pencilliumOccurs naturally in agriculture products such as ground nut and corn.Co-contaminant with aflatoxinClinical symptoms are: loss of weight,weakness, vomiting,diarrhoea,dehydration,convulsions and death.Causing symptoms of kodua poisoning (consumed kodo millet seed as staple food )

Page 25: Mycotoxicoses

ZEARALENONE

Produced by Fusarium species

Found in variety of infected cereals like maize, barley, wheat grains and sorghum

Cause genital disorders in domestic animals

Page 26: Mycotoxicoses

PATULIN

Derived from Pencillium patulum

It was initially thought to be the antiviral drug which relieve the symptoms of common cold

Subsequently realized as mycotoxin

Page 27: Mycotoxicoses

Preventing MycotoxinsUse “clean” procedures.Prevent contaminationInhibit mold growth• Drying• Refrigeration•Mold inhibitors

MUCH BETTER TO PREVENT FORMATION

Page 28: Mycotoxicoses

REFERENCE

Textbook of Medical mycology - Jagdish Chander