A comparison between Dactylaria gallopava and Scoleocobasidium humicola: first report of an infection in a tortoise caused by S. humicola

Scolecobasidium humicola, a soil fungus and etiologic agent of phaeohyphomycosis in fish, is herein reported to cause cutaneous lesions in a tortoise, Terrapine carolina var. carolina. S. humicola was isolated from lesions on the foot and dematiaceous hyphae were observed in KOH preparations of the biopsy and in stained preparations. This isolate and others were compared morphologically and physiologically with isolates of Dactylaria gallopava which it resembles. As a result of this investigation, we concluded that D. gallopava may be differentiated from S. humicola macroscopically, by the production in D. gallopava of an extensive diffusible purplishred to reddish-brown pigment when cultured on Sabouraud dextrose agar; microscopically, by the presence and usually predominance of conidia, whose apical cell is markedly wider than the basal cell, and usually constricted at the septum; and physiologically, by the ability to grow on media containing cycloheximide and by the ability to grow well at 36–45°C. In...