An autochthonous phaeohyphomycotic nail infection in Canada caused by Hendersonula toruloidea

A case of an autochthonous toenail infection caused by Hendersonula toruloidea is presented. H. toruloidea was characterized by thick, branching septate brown-walled hyphae of a non-dermatophyte in microscopic tissue mounts in 25% Na0H with 5% glycerol. Cultures grew out on Littman's agar and Sabouraud peptone glucose agar plus chloramphenicol, but only if cycloheximide was not present. In vitro, the H. toruloidea isolate was characterized by copious 1-to 2-celled hyaline to dark-brown arthroconidia deriving from the fragmentation of aerial hyphae. It is likely that more infections due to H. toruloidea will be diagnosed if cycloheximide-free media are routinely used in the isolation of organisms from suspected dermatophyte infections.