The postantibiotic effect of antifungal agents against common pathogenic yeasts.
A total of ten strains of Candida spp. and Cryptococcus neoformans were examined for the presence of the postantibiotic effect (PAE) after 0.5-2 h exposure to amphotericin B, 5-fluorocytosine, miconazole and ketoconazole. Significant PAEs were observed for amphotericin B and 5-fluorocytosine, but none for the imidazoles. The duration of the PAEs of amphotericin B ranged from 0.5-10.4 h for the Candida spp. and 2.8-10.6 h for the cryptococcos, while 5-fluorocytosine induced PAEs from 0.8-7.4 h and 2.4-5.4 h, respectively. Even though no PAEs were demonstrated for the imidazoles, the growth rate was persistently reduced by continuous exposure to concentrations as low as 1/1000 of the MIC of these agents. These findings may have implications for dosing antifungal agents in systemic yeast infections.
Turnidge
J D
JD
Department of Infectious Diseases and Microbiology, Monash Medical Centre, Clayton, Victoria, Australia.
Gudmundsson
S
S
Vogelman
B
B
Craig
W A
WA
D000666:Amphotericin B / Q000494:pharmacology*; D002175:Candida / Q000187:drug effects*; D003455:Cryptococcus neoformans / Q000187:drug effects*; D005437:Flucytosine / Q000494:pharmacology*; D007654:Ketoconazole / Q000494:pharmacology*; D008825:Miconazole / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests
D008825:Miconazole; D000666:Amphotericin B; D005437:Flucytosine; D007654:Ketoconazole