Physiological characteristics of environmental isolates of pathogenic dematiaceous fungi.

A total of 39 environmental isolates of pathogenic dematiaceous fungi (Fonsecaea pedrosoi: 14 isolates, Phialophora verrucosa: 6, Cladosporium carrionii: 9, Exophiala jeanselmei: 2, Ramichloridium subulatum: 6, Cladosporium tenuissimum: 1 and Phaeoisaria clematidis: 1) were evaluated for their various physiological characteristics including the ability to produce extracellular enzymes. Significant physiological characteristics included the ability of isolates of all the species except C. tenuissimum to decompose tyrosine, lyse human red blood cells, conversion of R. subulatum from filamentous to yeast form when cultured on Czapek-Dox agar and also on blood agar and the growth of C. tenuissimum on Sabouraud dextrose agar incorporating 3.6 M NaCl. Isolates of all the species except those of C. carrionii produced lipase, while only the isolates of P. verrucosa, E. jeanselmei and Ph. clematidis were positive for phospholipase.