An immunological procedure for the rapid identification of Phaeoannellomyces werneckii.

Phaeoannellomyces werneckii is identified on the basis of its annellidic conidiogenous cells and the production of two-celled conidia. Without the proper recognition of its annellidic mode of conidiogenesis, isolates of P. werneckii can be confused with other species of Phaeococcomyces, Exophiala, and Scolecobasidium constrictum. To overcome this problem, we developed exoantigen reagents capable of specifically identifying P. werneckii. Rabbit P. werneckii antiserum was rendered specific by adsorptions with antigens of Exophiala jeanselmei serotype 1, Exophiala moniliae, and Wangiella dermatitidis. Eighty-two dematiaceous yeast-like fungi, including 18 P. werneckii cultures, were tested in the immunodiffusion test against P. werneckii antisera. Exoantigen tests permitted the rapid and specific identification of the 18 P. werneckii isolates. Negative results were obtained with the 64 heterologous antigen extracts.