Coccidioides posadasii produces melanin in vitro and during infection.

Using techniques developed to study melanization in other fungi, we demonstrate that Coccidioides posadasii arthroconidia, spherules, and endospores produce melanin or melanin-like compounds in vitro and tissue forms synthesize pigment in vivo. Since melanin is an important virulence factor in other pathogenic fungi, it may affect the pathogenesis of coccidioidomycosis.