Taxonomic studies on Filobasidiella species and their anamorphs.

The taxonomy of Filobasidiella neoformans Kwon-Chung and F. bacillispora Kwon-Chung and their anamorphs were reinvestigated. Although the cross between the type culture of the two species failed to produce viable basidiospores, another pair of isolates did yield viable basidiospores. The segregation of phenotypic markers among the tetrads isolated from this inter specific cross proved that meiosis had occurred. On the basis of other previously known differences and the present genetic study, the two species are now considered to be two varieties of the species, F. neoformans. The anamorph of F. neoformans var. neoformans grew well at 37 degrees C in vitro and produced fatal infection in mice while that of F. neoformans var. bacillispora grew poorly at 37 degree C and failed to produce fatal infection in mice. Cryptococcus bacillisporus Kwon-Chung et Bennett is regarded as a synonym of C. neoformans var. gattii Vanbreuseghem et Takashio.