Laboratory diagnosis: 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 · Laboratory diagnosis

Sample item

What specimen issue can make sputum culture less useful?

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

The answer and the reasoning

B. Contamination with saliva

A saliva-contaminated sample may reflect oral flora rather than lower-respiratory secretions, reducing the diagnostic value of sputum culture results.

Option by option

  • A. Presence of leukocytes

    Leukocytes can support an inflammatory lower-respiratory sample.

  • B. Contamination with saliva (correct)

    Correct: saliva contamination lowers sputum culture quality.

  • C. Appropriate labeling

    Correct labeling improves specimen safety and interpretation.

  • D. Prompt transport

    Prompt transport preserves sample quality.

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, Contamination with saliva. A saliva-contaminated sample may reflect oral flora rather than lower-respiratory secretions, reducing the diagnostic value of sputum culture results.

Why is "Presence of leukocytes" not the answer?

Leukocytes can support an inflammatory lower-respiratory sample.

Why is "Appropriate labeling" not the answer?

Correct labeling improves specimen safety and interpretation.

Why is "Prompt transport" not the answer?

Prompt transport preserves sample quality.

What concept does this question test?

It tests Laboratory diagnosis in Microbiology. The correct option holds because: Correct: saliva contamination lowers sputum culture quality.

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 Laboratory diagnosis?

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.