Emerging agents of phaeohyphomycosis: pathogenic species of Bipolaris and Exserohilum.

Study of numerous living isolates of Bipolaris, Drechslera, Exserohilum, and Helminthosporium spp., as well as a mycological assessment of published case reports of phaeohyphomycosis attributed to these fungi, showed that Bipolaris australiensis, B. hawaiiensis, B. spicifera, Exserohilum longirostratum, E. mcginnisii, and E. rostratum are well-documented pathogens. Conidial shape, septation, and size, hilar characteristics, the origin of the germ tube from the basal cell and, to a lesser extent, from other conidial cells, and the sequence and location of the conidial septa are useful criteria for distinguishing these taxa.