A 32-year-old HIV-infected man from Manipur presents with fever, weight loss, papular skin lesions with central umbilication resembling molluscum contagiosum, and hepatosplenomegaly. Peripheral smear from a skin lesion shows intracellular yeast-like cells with a central transverse septum. Which organism is responsible?
- A Penicillium marneffei (Talaromyces marneffei) ✓
- B Histoplasma capsulatum
- C Leishmania donovani
- D Cryptococcus neoformans var. gattii
Correct answer: A. Penicillium marneffei (Talaromyces marneffei)
Explanation
Talaromyces (formerly Penicillium) marneffei is a thermally dimorphic fungus endemic to Southeast Asia and northeastern India and is an AIDS-defining opportunistic infection there. In tissue at 37 degrees Celsius it divides by fission, producing the characteristic central transverse septum within yeast cells, a feature absent in budding yeasts. Histoplasma shows narrow-based budding without a septum, Leishmania amastigotes contain a kinetoplast and nucleus rather than a division septum, and Cryptococcus shows a capsule with narrow-based budding.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.