Mycology: mycotoxins: practice question

A Microbiology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Microbiology · Mycology: mycotoxins

Sample item

A rural community in a hot humid region stores groundnuts and maize badly, and the incidence of hepatocellular carcinoma is high. Which fungal toxin from Aspergillus flavus is implicated?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

A. Aflatoxin B1

Aflatoxin B1 is converted in the liver to an epoxide that binds guanine in DNA and is associated with a characteristic p53 codon 249 mutation. With chronic hepatitis B it strongly raises hepatocellular carcinoma risk. Contaminated stored cereals and nuts are the usual source.

Option by option

  • A. Aflatoxin B1 (correct)

    Correct. Aflatoxin B1 from A. flavus is a hepatocarcinogen.

  • B. Ergot alkaloids

    Ergot alkaloids from Claviceps contaminating millet or rye cause ergotism with vasoconstriction.

  • C. Patulin

    Patulin is a mycotoxin of moulded apples that causes mainly gastrointestinal and neurological toxicity.

  • D. Ochratoxin A

    Ochratoxin A is nephrotoxic and comes mainly from Aspergillus ochraceus and Penicillium.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

More Microbiology questions

Questions about this Microbiology question

What is the answer to this Microbiology question?

The best answer is A, Aflatoxin B1. Aflatoxin B1 is converted in the liver to an epoxide that binds guanine in DNA and is associated with a characteristic p53 codon 249 mutation.

Why is "Ergot alkaloids" not the answer?

Ergot alkaloids from Claviceps contaminating millet or rye cause ergotism with vasoconstriction.

Why is "Patulin" not the answer?

Patulin is a mycotoxin of moulded apples that causes mainly gastrointestinal and neurological toxicity.

Why is "Ochratoxin A" not the answer?

Ochratoxin A is nephrotoxic and comes mainly from Aspergillus ochraceus and Penicillium.

What concept does this question test?

It tests Mycology: mycotoxins in Microbiology. With chronic hepatitis B it strongly raises hepatocellular carcinoma risk. Contaminated stored cereals and nuts are the usual source.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Mycology: mycotoxins?

Make a one-line identity card for each organism: shape and stain, defining test, toxin, disease and drug. Then use the flashcards and the other Microbiology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.