Bacteriology: 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 · Bacteriology

Sample item

What is the main virulence mechanism of tetanus toxin?

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

The answer and the reasoning

A. Blocks inhibitory neurotransmitter release

Tetanospasmin blocks release of inhibitory GABA and glycine from interneurons, leading to unopposed muscle contraction and spastic paralysis.

Option by option

  • A. Blocks inhibitory neurotransmitter release (correct)

    Correct: loss of inhibition causes spasticity.

  • B. Activates adenylate cyclase in gut

    Gut cAMP activation is cholera toxin.

  • C. Inhibits protein synthesis at ribosome

    Ribosome inhibition is diphtheria mechanism.

  • D. Destroys red cells directly

    Direct haemolysis is not tetanus action.

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, Blocks inhibitory neurotransmitter release. Tetanospasmin blocks release of inhibitory GABA and glycine from interneurons, leading to unopposed muscle contraction and spastic paralysis.

Why is "Activates adenylate cyclase in gut" not the answer?

Gut cAMP activation is cholera toxin.

Why is "Inhibits protein synthesis at ribosome" not the answer?

Ribosome inhibition is diphtheria mechanism.

Why is "Destroys red cells directly" not the answer?

Direct haemolysis is not tetanus action.

What concept does this question test?

It tests Bacteriology in Microbiology. The correct option holds because: Correct: loss of inhibition causes spasticity.

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 Bacteriology?

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.