Antifungal activity of cerebrospinal fluid against Cryptococcus neoformans and Candida species.

The effect of human cerebrospinal fluid (CSF) on the growth of Cryptococcus neoformans and Candida species was tested in RPMI-1640. CSF alone was highly fungistatic for both yeasts and inhibited growth in a concentration-dependent manner. Unlike human serum, CSF did not collaborate with fluconazole for killing C. neoformans. Molecular sieve fractionation of CSF on a G-200 Sephadex column yielded a highly antifungal fraction with a molecular weight around 66 kDa. On SDS-PAGE this fraction migrated as a major and a minor band corresponding to the mobility of bovine serum albumin. These novel findings suggest that CSF contains a factor(s) that provides resistance to the growth of C. neoformans or Candida species.