Abstract
We observed considerable variability in colony and microscopic morphology among isolates of Trichosporon beigelii. Deeply invasive clinical isolates showed four distinct morphotypes and spontaneous conversions among certain morphotypes and grew well at 37 degrees C. In contrast, superficial clinical and environmental isolates did not demonstrate such morphotypes or conversions, and most grew poorly at 37 degrees C. Thus, the morphologic and physiologic features of invasive clinical isolates of T. beigelii follow certain patterns distinct from those of superficial clinical and environmental isolates.