Curvularia, Exophiala, Scedosporium, Sporothrix, and Other Melanized Fungi

Abstract

This chapter covers most of the agents of phaeohyphomycosis, chromoblastomycosis, and sporotrichosis, as well as a number of agents of superficial and cutaneous disease. Pleoanamorphism is particularly striking in members of the black yeasts and in the genera Scedosporium and Triadelphia . Members of the genus Curvularia usually produce elongated conidia that are inconspicuously distoseptate and often possess an intermediate, asymmetrically swollen cell that gives the conidia a typically curved appearance. Exophiala is the main genus of clinically relevant black yeasts. Sporothrix brasiliensis is highly virulent and has caused large epidemics in Brazil; transmission occurs particularly through stray cats. Dematiaceous fungi are able to cause superficial infections, such as those of the skin and nails. Some melanized phialidic fungi were segregated from Phialophora on molecular and morphological grounds; these fungi now constitute small islands of clinical significance in the order Calosphaeriales, which otherwise contains plant‐associated moulds.