Blastomyces dermatitidis is known for what growth form?

• A. Broad-based budding yeast
• B. True hyphae with conidia
• C. Yeasts only at 37°C
• D. Endospore formation inside macrophages

Answer: (A)

Blastomyces dermatitidis is a dimorphic fungus that, in the human body, appears as large, thick-walled yeast cells that reproduce by broad-based budding. This broad-based budding is the characteristic morphological hallmark used to identify Blastomyces in tissue samples. In the environmental mold form at room temperature, it grows as septate hyphae with conidia, showing a different growth form. The other descriptions don’t fit the human-infective form: true hyphae with conidia describe the environmental mold rather than the yeast form; yeasts only at 37°C ignores the mold form seen outside the host; and endospore formation inside macrophages is not a feature of Blastomyces (more typical of other pathogens like Histoplasma in intracellular Yeast form).