[In vitro susceptibility to fluconazole of fungal strains freshly isolated from child patients with deep-seated mycoses]

Abstract

The susceptibility to fluconazole (FLCZ) were evaluated for 40 strains of 8 yeast species and 4 strains of 3 Aspergillus species, all of which were isolated from clinical specimens during clinical trials of FLCZ in child patients performed from January 1991 to January 1993 in this country. The in vitro activity of FLCZ against yeast isolates and Aspergillus isolates were measured using the microdilution method with semisolid SAAMF (synthetic amino acid medium fungal) agar and the macrodilution method with Eagle MEM (minimum essential medium), respectively, using amphotericin B (AMPH) and flucytosine as the reference drugs. Out of all yeast species tested, Candida albicans and Candida tropicalis were the most susceptible to FLCZ with geometric mean (GM)-MICs of < 0.4 microgram/ml that were far less than the corresponding values for AMPH or flucytosine. On the other hand, FLCZ showed the lowest activity against Candida krusei and Candida glabrata with GM-MICs of approximately 10 micrograms/ml that were slightly higher than those for AMPH. The susceptibilities to FLCZ of Candida parapsilosis, Candida pelliculosa (anamorph of Hansenula anomala), Candida famata, and Trichosporon cutaneum were intermediate. Antifungal activities of FLCZ and the 2 reference drugs against aspergilli were determined on the basis of the amount of total protein recovered from drug-treated cultures relative to that from drug-free control cultures. Fifty percent and 90% inhibitory concentrations of FLCZ against 2 isolates of Aspergillus fumigatus were 6.25-25 micrograms/ml and 50 micrograms/ml, respectively. Against this and 2 other species of Aspergillus, AMPH appeared more highly active than FLCZ.