Mycotoxins

1a. What are mycotoxins? Give two examples of mycotoxins.

b. When in the fungal growth phase are they generally produced? What are two ways that toxins may be ingested?

2. What are host-specific toxins?

3. What is meant by mycetism?

4. Determine if the following statements are true or false. Understand why they are.

a. mycotoxins are mostly secondary metabolites

b. mycotoxis are often species-specific or are produced by a subset of related species.

c. Turkey-X disease was caused by a mushroom poison.

d. Aflatoxin B1 is capable of damaging DNA

e. Peanuts, cottonseed and corn are generally not affected by aflatoxins, thus their aflatoxins levels are not routinely monitored.

f. Aflatoxins in cattle feed can be metabolized thus resulting in contamination of the milk produced by cows that eat such feed.

g. No aflatoxin outbreaks have been reported in the USA, a testament to our food testing programs.

h. A mycotoxin may have different effects on different animals.

i. Zero parts per billion (ppb) is not a practically achievable mycotoxin level for food.

5. Why are mycotoxins called cryptic toxins?

6. Aflatoxins are a main type of mycotoxin. Name the fungal genus that produces aflatoxins.

b. Are aflatoxins produced by one or more species. Explain.

7. How do aflatoxins get into poultry, cattle and milk?

8. What is meant by "chronic aflatoxicosis"?

9. Some mycotoxins are genotoxins. What does this mean?

10. Why are countries near the equator generally more likely to have aflatoxin contamination of foods?

12. European countries are very strict on the level of aflatoxins allowed in foods. Why is it possible for European growers to meet these standards while growers in other countries struggle to meet these levels?

13. How are field isolated strains of Aspergillus flavus, like AF36, being used to control aflatoxin contamination?

14. What are some of the negative impacts of aflatoxins on humans?

15. Match the fungus with the toxin it produces: