In-vitro antifungal activities of sulfa drugs against clinical isolates of Aspergillus and Cryptococcus species.

In vitro susceptibilities of ten clinical isolates, including five strains of Cryptococcus neoformans var. grubii and five strains of Aspergillus fumigatus, were determined against nine sulfa drugs using a microdilution method. Among the five tested media, minimum inhibitory concentration (MIC) values were observed only in YNB medium: no detectable level MIC value of less than 125 microg/ml was observed in the four remaining media against Cryptococcus species. Of the nine sulfa drugs, of which sulfaphenazole showed the highest antifungal activity, the MIC values for A. fumigatus and C. neoformans var. grubii were, respectively, 64 microg/ml and 4-8 microg/ml, suggesting high susceptibility of C. neoformans to sulfa drugs.