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 a major virulence factor of Streptococcus pyogenes?

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

The answer and the reasoning

B. M protein

M protein helps Streptococcus pyogenes resist phagocytosis and is linked to strain-specific immune responses and poststreptococcal complications.

Option by option

  • A. Endospore

    S. pyogenes does not form endospores.

  • B. M protein (correct)

    Correct: M protein is a key antiphagocytic streptococcal factor.

  • C. Protein A

    Protein A is associated with Staphylococcus aureus.

  • D. Lipopolysaccharide

    Lipopolysaccharide is a gram-negative outer-membrane component.

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 B, M protein. M protein helps Streptococcus pyogenes resist phagocytosis and is linked to strain-specific immune responses and poststreptococcal complications.

Why is "Endospore" not the answer?

S. pyogenes does not form endospores.

Why is "Protein A" not the answer?

Protein A is associated with Staphylococcus aureus.

Why is "Lipopolysaccharide" not the answer?

Lipopolysaccharide is a gram-negative outer-membrane component.

What concept does this question test?

It tests Bacteriology in Microbiology. The correct option holds because: Correct: M protein is a key antiphagocytic streptococcal factor.

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.