Paracoccidioides brasiliensis is described as having Captain's wheel morphology and is associated with the lungs and Latin America. Which organism is this?

• A. Paracoccidioides brasiliensis
• B. Histoplasma capsulatum
• C. Coccidioides immitis
• D. Aspergillus fumigatus

Answer: (A)

Captain's wheel morphology is the hallmark feature of Paracoccidioides brasiliensis. In tissue, this dimorphic fungus shows yeast cells with multiple narrow buds arranged around a central cell, creating a wheel-like or captain’s wheel appearance. It is endemic to Latin America and classically causes paracoccidioidomycosis, often starting in the lungs and potentially disseminating. Other fungi don’t display this budding pattern: Histoplasma capsulatum appears as small intracellular yeasts within macrophages, Coccidioides immitis forms large spherules filled with endospores, and Aspergillus fumigatus is a mold with septate hyphae and acute angle branching. Thus, the organism described is Paracoccidioides brasiliensis.