Mycology: Talaromyces marneffei: 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 · Mycology: Talaromyces marneffei

Sample item

A man with advanced HIV from north-east India has fever, weight loss and umbilicated papules on the face. A smear shows yeast-like cells dividing by a central septum, and a culture at 25 degrees C grows a mould with a red diffusible pigment. Which organism is responsible?

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

The answer and the reasoning

C. Talaromyces marneffei

Talaromyces marneffei is a thermally dimorphic fungus linked to bamboo rats and endemic in South-East Asia and north-east India, causing disseminated disease in advanced HIV. Its yeast form multiplies by fission, producing a transverse septum, unlike budding yeasts. The mould form releases a red pigment into the agar, and treatment is amphotericin B followed by itraconazole.

Option by option

  • A. Blastomyces dermatitidis

    Blastomyces shows broad-based budding yeasts and has no red pigment.

  • B. Histoplasma capsulatum

    Histoplasma yeasts divide by budding and the mould form lacks a red pigment.

  • C. Talaromyces marneffei (correct)

    Correct. Fission yeast with a septum and a red diffusible pigment define T. marneffei.

  • D. Cryptococcus neoformans

    Cryptococcus shows narrow-based budding and a capsule and is not dimorphic.

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.

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Questions about this Microbiology question

What is the answer to this Microbiology question?

The best answer is C, Talaromyces marneffei. Talaromyces marneffei is a thermally dimorphic fungus linked to bamboo rats and endemic in South-East Asia and north-east India, causing disseminated disease in advanced HIV.

Why is "Blastomyces dermatitidis" not the answer?

Blastomyces shows broad-based budding yeasts and has no red pigment.

Why is "Histoplasma capsulatum" not the answer?

Histoplasma yeasts divide by budding and the mould form lacks a red pigment.

Why is "Cryptococcus neoformans" not the answer?

Cryptococcus shows narrow-based budding and a capsule and is not dimorphic.

What concept does this question test?

It tests Mycology: Talaromyces marneffei in Microbiology. Its yeast form multiplies by fission, producing a transverse septum, unlike budding yeasts. The mould form releases a red pigment into the agar, and treatment is amphotericin B followed by itraconazole.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. 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 Mycology: Talaromyces marneffei?

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.