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

Which organism classically causes 'currant jelly' sputum?

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

The answer and the reasoning

D. Klebsiella pneumoniae

Klebsiella pneumoniae causes necrotising lobar pneumonia, with thick, blood-tinged mucoid 'currant jelly' sputum, especially in alcohol use disorder and diabetes. Pneumococcus gives rusty sputum.

Option by option

  • A. Mycoplasma pneumoniae

    Mycoplasma causes atypical pneumonia with a dry cough.

  • B. Legionella pneumophila

    Legionella causes pneumonia with diarrhoea and hyponatraemia.

  • C. Streptococcus pneumoniae

    Streptococcus pneumoniae gives rusty-coloured sputum.

  • D. Klebsiella pneumoniae (correct)

    Correct. Its capsule makes sputum thick and mucoid, tinged with blood.

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, Klebsiella pneumoniae. Klebsiella pneumoniae causes necrotising lobar pneumonia, with thick, blood-tinged mucoid 'currant jelly' sputum, especially in alcohol use disorder and diabetes.

Why is "Mycoplasma pneumoniae" not the answer?

Mycoplasma causes atypical pneumonia with a dry cough.

Why is "Legionella pneumophila" not the answer?

Legionella causes pneumonia with diarrhoea and hyponatraemia.

Why is "Streptococcus pneumoniae" not the answer?

Streptococcus pneumoniae gives rusty-coloured sputum.

What concept does this question test?

It tests Bacteriology in Microbiology. Pneumococcus gives rusty sputum.

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.