Cryptococcus neoformans varieties as agents of cryptococcosis in Brazil.

The study of the clinical isolates of Cryptococcus neoformans from 83 Brazilian patients with disseminated cryptococcosis showed that 75 were C. neoformans var. neoformans and 8 were var. gattii. Twenty-seven isolates were serotyped; all 19 var. neoformans were serotype A and all 8 var. gattii were serotype B. The correlation of the varieties of C. neoformans with the presence or not of hosts predisposing conditions to the mycosis showed that: (1) cryptococcosis caused by gattii variety occurred in 7 (58.3%) of the 12 nonimmunosuppressed patients, and (2) cryptococcosis caused by neoformans variety occurred in 65 (98.5%) of the 66 AIDS patients and in all 5 patients with other immunosuppressive conditions. The comparison of the distribution of the gattii and neoformans varieties between the nonimmunosuppressed and immunosuppressed patients showed a significant statistical difference (p < 0.01).