Mycotoxins general account types &importance

1. Mycotoxins -General account, types
& importance
Vaishali S.Patil
Professor, Department of Botany
Shri Shivaji College of Arts, Commerce & Science Akola

2. Introduction
• A mycotoxin (from the Greek mykes, "fungus" and toxini,
"toxin")is a toxic secondary metabolite produced by
organisms of the fungus kingdom and is capable of causing
disease and death in both humans and other animals.
• The term 'mycotoxin' is usually reserved for the toxic
chemical products produced by fungi that readily
colonize crops.
• One mold species may produce many different mycotoxins,
and several species may produce the same mycotoxin.
• Mycotoxins are not necessary for the growth or the
development of the fungi.
• Mycotoxins weaken the receiving host, they may improve
the environment for further fungal proliferation.

3. Examples of mycotoxins causing human and animal illness
include aflatoxin, citrinin, fumonisins, ochratoxin
A, patulin, trichothecenes, zearalenone, and ergot
alkaloids such as ergotamine.
Production-
Most fungi are aerobic (use oxygen) and are found almost
everywhere in extremely small quantities due to the diminute
size of their spores. They consume organic
matter wherever humidity and temperature are sufficient.
Where conditions are right, fungi proliferate into colonies and
mycotoxin levels become high. The production of toxins
depends on the surrounding intrinsic and extrinsic
environments and these substances vary greatly in their
toxicity, depending on the organism infected and its
susceptibility, metabolism, and defence mechanisms.

4. Types
1.Aflatoxins -
•It is produced by Aspergillus species of fungi, such as A. flavus and A.
parasiticus.
•Types- B1, B2, G1, and G2.
•Aflatoxin B1, the most toxic, is a potent carcinogen and has been
directly correlated to adverse health effects, such as liver cancer, in many
animal species.
•Aflatoxin are largely associated with commodities produced in tropic
and subtropics such as cotton, peanuts, spices, pistachios and maize.
•They are regularly found in improperly stored staple commodities such
as cassava, chili peppers, cottonseed, millet, peanuts, rice, sesame
seeds, sorghum, sunflower seeds, sweetcorn, tree nuts, wheat, and a
variety of spices.

5. •Children are particularly affected by aflatoxin exposure,
which is associated with stunted growth, delayed
development, liver damage, and liver cancer.
•Aflatoxin transformation products are sometimes found in
eggs, milk products, and meat when animals are fed
contaminated grains.
•High-level aflatoxin exposure produces an
acute hepatic necrosis (acute aflatoxicosis), resulting later
in cirrhosis or carcinoma of the liver. Acute liver failure is
made manifest by bleeding, edema, alteration in digestion,
changes to the absorption and/or metabolism of nutrients, and
mental changes and/or coma.
•A regular diet including apiaceous vegetables, such
as carrots, parsnips, celery, and parsley may reduce
the carcinogenic effects of aflatoxin.

6. Aflatoxin

8. 2.Ochratoxin-
• It is produced by Penicillium and Aspergillus species
• Types- A, B, and C.
• The three forms differ in that Ochratoxin B (OTB) is a nonchlorinated
form of Ochratoxin A (OTA) and that Ochratoxin C (OTC) is an ethyl
ester form Ochratoxin A.
• Aspergillus ochraceus is found as a contaminant of a wide range of
commodities including beverages such as beer and wine. Ochratoxin
A is known to occur in commodities such as cereals, coffee, dried
fruit, and red wine.
• Aspergillus carbonarius is the main species found on vine fruit,
which releases its toxin during the juice making process. OTA has
been labeled as a carcinogen and a nephrotoxin, and has been linked
to tumors in the human urinary tract.
• Meat and meat products can be contaminated with this toxin.
• Exposure to ochratoxins through diet can cause acute toxicity in
mammalian kidneys.

9. Ochratoxin

10. Ochratoxin A Ochratoxin B
Ochratoxin C Ochratoxin TA

11. 3.Citrinin-
•Discovered by H. Raistrick and A.C. Hetherington in the
1930s
•It is produce by species of Penicillium and Aspergillus.
•It is associated with yellowed rice disease in Japan and acts as
a nephrotoxin in all animal species tested.
• It is associated with many human foods
(wheat, rice, corn, barley, oats, rye, and food colored
with Monascus pigment).
•It can also act synergistically with Ochratoxin A to
depress RNA synthesis in murine kidneys.
•Health hazards caused by inhaled citrinin or through dermal
exposure of citrinin is largely unclear. Researchers found that
citrinin is also used in indoor materials.
•Citrinin are acute toxicity, nephrotoxicity, genotoxicity and

12. its carcinogenicity.
•Citrinin toxicity reduced cytokine production, inhibition of RNA and
DNA synthesis, induction of oxidative stress, inhibition of nitride oxide
gene expression, increase in ROS production and activation of apoptotic
cell death via signal transduction pathways and the caspase-cascade
system.

14. 4. Ergot Alkaloids-
•They are compounds produced as a toxic mixture of alkaloids in
the sclerotia of species of Claviceps, which are common pathogens of
various grass species.
• The ingestion of ergot sclerotia from infected cereals, commonly in the
form of bread produced from contaminated flour, causes ergotism, the
human disease historically known as St. Anthony's Fire.
•There are two forms of ergotism: gangrenous, affecting blood supply to
extremities, and convulsive, affecting the central nervous system.
•The severe burning sensations in the limbs which was one of the
symptoms,muscle spasms, fever and hallucinations and the victims may
appear dazed, be unable to speak, become manic, or have other forms of
paralysis or tremors, and suffer from hallucinations and other distorted
perceptions. This is caused by serotonergic stimulation of the central
nervous system by some of the alkaloids.
•The second type of ergotism is marked by violent burning, absent
peripheral pulses and shooting pain of the poorly vascularized distal

15. alkaloids on the vascular system due to vasoconstriction, sometimes
leading to gangrene and loss of limbs due to severely restricted blood
circulation
•Ergot alkaloids have been used pharmaceutically.
Types-
G1 — land grasses of open meadows and fields;
G2 — grasses from moist, forest, and mountain habitats;
G3 (C. purpurea var. spartinae) — salt marsh grasses
(Spartina, Distichlis).
•Ergot alkaloids have a wide range of biological activities including
effects on circulation and neurotransmission.
•The neurotropic activities of the ergot alkaloids may also
cause hallucinations and attendant irrational behaviour, convulsions, and
even death. Other symptoms include
strong uterine contractions, nausea, seizures, high fever, vomiting, loss of
muscle strength and unconsciousness. Since the Middle Ages, controlled
doses of ergot were used to induce abortions and to stop maternal
bleeding after childbirth.

16. Ergot Alkaloids

17. 4.Patulin-
• It is a toxin produced by the P. expansum, Aspergillus, Penicillium,
and Paecilomyces fungal species.
• P. expansum is especially associated with a range of
moldy fruits and vegetables, in particular rotting apples and figs.
• It is destroyed by the fermentation process and so is not found in apple
beverages, such as cider.
•Although patulin has not been shown to be carcinogenic, it has been
reported to damage the immune system in animals.
•Patulin was originally used as an antibiotic against Gram-positive and
Gram-negative bacteria,
•It was specifically trialed to be used against the common cold. Patulin is
used as a potassium-uptake inhibitor in laboratory applications.
• Patulin stimulates suicidal erythrocyte death under physiological
concentrations.
•Patulin has shown antimicrobial properties against some
microorganisms.

18. Patulin

19. 5.Fusarium-
•These toxins are produced by over 50 species
of Fusarium and have a history of infecting the grain of
developing cereals such as wheat and maize.
•They include a range of mycotoxins, such as: the fumonisins,
which affect the nervous systems of horses and may cause
cancer in rodents; the trichothecenes, which are most strongly
associated with chronic and fatal toxic effects in animals and
humans; and zearalenone, which is not correlated to any fatal
toxic effects in animals or humans.
•Some of the other major types of Fusarium toxins include:
beauvercin and enniatins, butenolide, equisetin, and fusarins.
Some species may cause a range of opportunistic infections in
humans.

20. •In humans whose immune systems are weakened in a
particular way, (neutropenia, i.e., very low neutrophils count),
aggressive fusarial infections penetrating the entire body and
blood stream (disseminated infections) may be caused by
members of the Fusarium solani complex, Fusarium
oxysporum, Fusarium verticillioides, Fusarium
proliferatum and, rarely, other fusarial species.
•In humans with normal immune systems, fusarial infections
may occur in the nails (onychomycosis) and in
the cornea (keratomycosis or mycotic keratitis).

21. Fusarium

22. 6.Wild mushrooms-
• Ingestion of misidentified mushrooms containing
mycotoxins may result in hallucinations.
• The cyclopeptide-producing Amanita phalloides is well
known for its toxic potential and is responsible for
approximately 90% of all mushroom fatalities.
•The other primary mycotoxin groups found in mushrooms
include: orellanine, monomethylhydrazine, disulfiram-like,
hallucinogenic indoles, muscarinic, isoxazole, and
gastrointestinal (GI)-specific irritants
cause vomiting and diarrhea (sometimes requiring
hospitalization)
•Serious symptoms do not always occur immediately after
eating, often not until the toxin attacks the kidney or liver,
sometimes days or weeks later.

23. Poisonous mushrooms
Amanita pantherina Chlorophyllum molybdites Entoloma
Inocybe Clitocybe Tricholoma pardinum
Hypholoma fasciculare, Paxillus involutus Rubroboletus satanas

24. Turbinellus floccosus
Hebeloma crustuliniforme Russula emetica Agaricus hondensis
Lactifluus piperatus Lactarius vinaceorufescens Ramaria gelatinosa
Amanita muscaria Tricholoma equestre

25. In indoor environments- Buildings are another source of mycotoxins.
Some of the mycotoxins in the indoor environment are produced
by Alternaria, Aspergillus (multiple forms), Penicillium,
and Stachybotrys. Stachybotrys chartarum contains a higher number of
mycotoxins than other molds grown in the indoor environment and has
been associated with allergies and respiratory inflammation. S.
chartarum can evoke allergic sensitization, inflammation, and
cytotoxicity in the upper and lower respiratory tracts.
In food- Mycotoxins can appear in the food chain as a result of fungal
infection of crops, either by being eaten directly by humans or by being
used as livestock feed. Spices are susceptible substrate for growth of
mycotoxigenic fungi and mycotoxin production.Red chilli, black pepper,
and dry ginger were found to be the most contaminated spices.
In animal food- Dimorphic fungi, which include Blastomyces
dermatitidis and Paracoccidioides brasiliensis, are known causative
agents of endemic systemic mycoses.

26. Paracoccidioides brasiliensis Penicillium,
Alternaria, Paecilomyces Stachybotrys
Blastomyces dermatitidis