A PHEOHYPHOMYCOTIC CYST AND PERITONITIS CAUSED BY PHIALEMONIUM SPECIES AND A REEVALUATION OF ITS TAXONOMY

Two cases of human fungal infections caused by members of the genus Ph ialemonium, a genus proposed by Gams and McGinnis (1983) for fungi int ermediate between the genera Acremonium and Phialophora, are presented . The first case was a phaeohyphomycotic cyst on the foot of a renal t ransplant recipient. The fungus was detected by direct examination and histopathology and was recovered by several procedures over 4 months. It was flat, glabrous, and white becoming yellow with the production of a diffusible yellow pigment; it had conidiophores that were mostly solitary and lateral and terminal phialides and adelophialides with di stinct collarettes producing cylindrical to curved conidia. The isolat e resembled both Phialemonium dimorphosporum and Phialemonium curvatum , although its characteristics were more consistent with those of the latter. The second case was peritonitis in a renal transplant recipien t. The fungus was white-to-cream colored and yeast like, but later bec ame black with a green diffusible pigment, and produced obovoid conidi a; it was easily identified as Phialemonium obovatum. Difficulties enc ountered in the identification and taxonomy of members of this genus h ighlight the need for standardized conditions, e.g., potato dextrose a gar culture incubated at 24 to 25-degrees-C for morphologic comparison s, to control significant variations due to culture conditions.