Lecture 12: Mycotoxins

Question 1

Mycotoxins

Answer 1

Toxic secondary fungal metabolites that contaminate various food substances and agricultural products and are a serious health risk to humans and animals

Question 2

Mycotoxicoses

Answer 2

Poisoning due to exposure to mycotoxins, Amy be acute or chronic

Question 3

Symptoms depend on…

Answer 3

• Type of mycotoxin
• The amount and duration of the exposure
• The age, health and gender of the exposed individual
• Synergic effects

Question 4

Major mycotoxins

Answer 4

• Aflatoxins
• Ergot alkaloids
• Fumonisins
• Patulin
• Zearalenone

Question 5

Aflatoxins

Answer 5

Contamination of nuts and grains. pre-harvest linked to drought stress and poor storage conditions

Question 6

Aflatoxin fungi

Answer 6

Aspergillus flavus and Aspergillus parasiticus

Question 7

Major groups of Aflatoxins

Answer 7

B1&2 and G1&2
They are fluorescent under UV and chromatographic mobility during TLC

Question 8

Aflatoxin contamination

Answer 8

• Increased mortality in farm animals
• Lowers value of grains

Question 9

Milk as indirect source of aflatoxins

Answer 9

Cows biotransform aflatoxin B1 into hydroxylated form aflatoxin M1
Aflatoxins may cause cancer and immune suppression

Question 10

Which organ does aflatoxins target

Answer 10

Liver

Question 11

Ergot alkaloids

Answer 11

Includes lysergic acid and pure ergotamine

Question 12

Fungi that produce ergot alkaloids

Answer 12

Claviceps spp.

Question 13

Ergotism

Answer 13

• Anthony’s Fire
• Ergot replace seeds in flower spike of grains
• Flour and resulting baked goods contaminated
• Modern grain processing has largely eliminated disease

Question 14

Convulsive ergotism

Answer 14

• Neural dysfunction
• Severe muscular pIN
• Hot-cold sensations
• Hallucnations

Question 15

Gangrenous ergotism

Answer 15

• Constriction of blood vessels
• burning pain
• Gangrene/necrosis of limbs

Question 16

Fumonisins

Answer 16

endophyte of maize
* Analogues A,B,P

Question 17

Fungi that produce fumonisins

Answer 17

Fusarium spp. (F.verticilliodes)

Question 18

Fumonisin B1

Answer 18

• Leukoencephalomalacia (Horses)
• Pulmonary oedema syndrome (pigs)
• Toxic to liver, pancreas, kidneys, lungs
• phytotoxic to some plants
• Linked to human oesophageal cancer

Question 19

Patulin

Answer 19

Soft rot pathogen of apples, pears, cherries and deciduous fruits
* Regularly found in unfermented apple juice

Question 20

Toxic effects

Answer 20

Oedema, haemorrhage, damage to liver, spleen and kidneys

Question 21

Fungi that produce Patulin

Answer 21

Penicillium expansum

Question 22

Zearalenone

Answer 22

Contaminates cereal grain

Question 23

Fungi that produce zearalenone

Answer 23

Fusarium graminearum

Question 24

Hyperestrogenism (pigs) symptoms caused by zearalenone

Answer 24

swelling of vulva
Infertility
stillbirths
small litters

Question 25

Impact of mycotoxin contamination in commercial farming

Answer 25

• Fungicide application
• Controlled storage conditions
• Mechanical dehulling and milling technologies

Question 26

Impact of mycotoxin contamination in subsistence farming

Answer 26

• High risk of exposure
• Socio-economic factors
• no regulations enforced

Question 27

Strategies for mycotoxin control

Answer 27

• Awareness
• Use of improved crop varieties
• Technologies and community-based practices to reduce exposure
• Dietary diversity