Flucytosine primary resistance in Candida species and Cryptococcus neoformans.
The in vitro activity of flucytosine (5FC) against 1,140 clinical isolates of Candida spp. and Cryptococcus neoformans was evaluated and compared with the activity of amphotericin B, fluconazole and itraconazole. Overall, 87.72% (1,000/1,140) of yeasts were susceptible to 5FC. This agent showed less potent in vitro activity against Candida glabrata, Candida krusei, Candida guilliermondii and Cryptococcus neoformans (MIC90s, 8-16 microg/ml) and intermediate activity or resistance to 6.5% of Candida albicans, 5.1% of Candida tropicalis and 0.8% of Candida parapsilosis strains. Amphotericin B showed potent activity against isolates with an MIC of 5FC > or = 8 microg/ml. A total of 112 of 140 strains that were SFC-intermediate or -resistant showed decreased susceptibility to azoles (P < 0.01).
Cuenca-Estrella
M
M
Servicio de Micología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda (Madrid), Spain. mcuenca-estrella@isciii.es
Díaz-Guerra
T M
TM
Mellado
E
E
Rodríguez-Tudela
J L
JL
D000935:Antifungal Agents / Q000494:pharmacology*; D002175:Candida / Q000187:drug effects*; D003455:Cryptococcus neoformans / Q000187:drug effects*; D004352:Drug Resistance, Microbial; D005437:Flucytosine / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests
D000935:Antifungal Agents; D005437:Flucytosine