Background: Micafungin (FK463) is a new investigational intravenous antifungal of the ``candin-family'' with potent in vitro and in vivo activity against Candida spp. The aim of the present study was to investigate the effect of micafungin (FK463) and itraconazole on adherence, as a first step of infection, of azole-sensitive and azole-resistant C. albicans isolates to epithelial cells. Methods: An in vitro assay using microtestplate technology and fluorescence measurement was developed. Epithelial cells were infected with Candida in the presence or in the absence of the antifungal substances. Remaining adherent Candida cells were measured by staining the yeasts with the fluorescence dye Calcofluor white. Additionally, a variation of this adherence model was used that mimicks the situation of thrush. A group of paired C. albicans isolates, either a fluconazole-susceptible and a fluconazole-resistant isolate of the same patient, was compared for their adherence pattern in the presence of both antifungals. Results: Micafungin (FK463) showed a marked dose-dependent inhibitory effect, up to 90% of the value of control tests without drug, on the adherence of C. albicans SC5314, used as reference strain in the laboratory. With itraconazole a dose dependent reduction of Candida adherence was observed in the range of 50% at maximum No significative difference in the adherence behavior between azole-susceptible and -resistant isolates was observed, whereas micafungin showed a distinct better effect on blocking Candida adherence in this model. Conclusion: This study indicates that micafungin could be an appropriate drug for the treatment of infections with azole-resistant strains of C. albicans.
Full conference title:
42nd Interscience Conference on Antimicrobial Agents and Chemotherapy
- ICAAC 42nd