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.
Department of Infectious Diseases and Microbiology, Monash Medical Centre, Clayton, Victoria, Australia.
J D
JD
Turnidge
S
S
Gudmundsson
B
B
Vogelman
W A
WA
Craig
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