Histoplasma capsulatum - microscopic aspect of the saprophytic phase

Histoplasma capsulatum var. capsulatum hyphae are thin and septated. Small, round or piriform, microconidia [2-3 µm], sometimes larger [8-10 µm], smooth and two layers walled. Macroconidia [10-25 µm] are round, echinulated, with thick walls. They are settled at the end of a long conidiophore. Responsible for histoplasmosis.