Aspergillus fumigatus is an opportunistic pathogen, especially in an immunocompromised host. This fungus grows in a hyphal form in infected tissues; therefore, new tests to examine hyphal susceptibility are needed. In this study, we measured the mycotic activity of miconazole (MCZ) contained in human serum against A. fumigatus using the BioCell-Tracer method. Three serum samples were obtained from the same patient who was injected with 600mg b. i. d. MCZ daily for 2 days. The concentrations of MCZ in the serum sample were 8.8, 3.5, and 1.6μg/ml, respectively.
The serum containing 8.8μg/ml of MCZ inhibited hyphal growth 90 minutes after administration, and the hypha stopped growing. The serum containing 3.5μg/ml MCZ stopped hypha growth 100 minutes after administration, but re-growth of the hypha was observed at this concentration of MCZ. Serum containing 1.6μg/ml did not inhibite hyphal growth, nor did control serum have any inhibitory activity foward hyphae. Based on these results, we conclude that the BioCell-Tracer is a useful method for determining the effects on filamentous fungi of antifungal agents in the serum.
