A 22-year-old man presents with hypopigmented macules on the chest and back with fine scaling. KOH mount of the scrapings shows clusters of round budding yeast cells mixed with short curved hyphae. What is the culture requirement of this organism?

• A Grows readily on plain Sabouraud dextrose agar at room temperature
• B Cannot be cultured on artificial media and requires tissue inoculation
• C Requires cycloheximide-free media incubated at 37 degrees Celsius
• D Requires supplementation with olive oil or other long-chain fatty acids ✓

Explanation

The KOH picture of round budding yeasts with short hyphae is described as spaghetti and meatballs and is diagnostic of Malassezia furfur, the cause of pityriasis versicolor. Malassezia is lipid dependent because it lacks the enzymes for fatty acid synthesis, so cultures require Sabouraud agar overlaid with olive oil or another lipid supplement. It grows readily on routine media if lipid is supplied, so options A and B are wrong.

Reference: Jagdish Chander, Textbook of Medical Mycology, 4th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.