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 virulence factor allows Staphylococcus aureus to bind immunoglobulin Fc portions?

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

The answer and the reasoning

D. Protein A

Protein A binds the Fc portion of IgG, interfering with opsonization and phagocytosis and contributing to Staphylococcus aureus virulence.

Option by option

  • A. Flagellum

    Flagella provide motility rather than IgG binding.

  • B. Capsule only

    Capsules may impair phagocytosis but do not define this Fc binding.

  • C. M protein

    M protein is a streptococcal virulence factor.

  • D. Protein A (correct)

    Correct: Protein A binds IgG Fc and impairs opsonization.

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 D, Protein A. Protein A binds the Fc portion of IgG, interfering with opsonization and phagocytosis and contributing to Staphylococcus aureus virulence.

Why is "Flagellum" not the answer?

Flagella provide motility rather than IgG binding.

Why is "Capsule only" not the answer?

Capsules may impair phagocytosis but do not define this Fc binding.

Why is "M protein" not the answer?

M protein is a streptococcal virulence factor.

What concept does this question test?

It tests Bacteriology in Microbiology. The correct option holds because: Correct: Protein A binds IgG Fc and impairs opsonization.

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.