Relationship between protease production and capsule size in Cryptococcus neoformans

Purpose. In this study growth, capsule and protease activity at different t emperatures were examined in order to observe a possible relationship betwe en protease production of different Cryptococcus neoformans strains and the size of their capsule. Materials and methods. Protease production was evaluated using the diameter of proteolysis on chemicaly defined agar media at different temperatures i n 40 strains of C. neoformans isolated from 21 AIDS patients and from 19 bi rd droppings. Results. Most C. neoformans strains isolated from AIDS patients and bird dr oppings, produced protease both at 37 degrees C and at 28 degrees C. There also appeared to be a possible correlation between protease production and the size of the capsule in the strains isolated from AIDS patients but not in the bird droppings strains.