Which fungus is notable for lacking a true capsule?

• A. Cryptococcus neoformans
• B. Paracoccidioides brasiliensis
• C. Coccidioides immitis
• D. Histoplasma capsulatum

Answer: (D)

A key idea here is that a capsule is a notable virulence factor for some fungi, helping them resist phagocytosis. Cryptococcus neoformans is the classic encapsulated fungus, with a prominent polysaccharide capsule that can be seen as a halo around the yeast and is detectable by special stains. Histoplasma capsulatum, in contrast, does not have a true capsule. In tissue, it appears as tiny intracellular yeasts inside macrophages, and its virulence relies on intracellular survival rather than a capsule.

So, the fungus notable for lacking a true capsule is Histoplasma capsulatum. The other fungi on the list have distinctive tissue forms or structures (such as large spherules with endospores in Coccidioides or multinucleate budding forms in Paracoccidioides) but their defining features are not capsule-based.