Abstract:

Objective To explore the susceptibility of Candida albicans biofilms to micafungin. Methods In vitro model of C. albicans biofilm was established in 96-well microtiter plates with 30 C. albicans isolates from the Department of Mycology, Changhai Hospital, Shanghai. The susceptibility of C. albicans biofilms to fluconazole, amphotericine B and micafungin was evaluated by colorimetric XTT-reduction assay. Sessile MIC80 (SMIC80), defined as the lowest antifungal concentration at which an 80% reduction in fungal growth was achieved, was determined. Results Of the 30 C. albicans isolates grown in sessile states, all were resistant to fluconazole （SMIC80≥64 μg/mL）, 4 sensitive to amphotericine B （SMIC80≤1 μg/mL）, 26 resistant to amphotericine B （SMIC80 > 1 μg/mL）, 27 sensitive to micafungin （SMIC80 < 16 μg/mL）, 3 resistant to micafungin （SMIC80≥16 μg/mL）. Statistical analysis revealed a significant difference in the activity against C. albicans biofilms between micafungin and fluconazole （χ2 = 736.36, P < 0.01), micafungin and amphotericine B （χ2 = 529.95, P < 0.01）, but not between anphotericine B and fluconazole (χ2 = 2.29, P > 0.05）. Conclusion C. albicans biofilms are resistant to routine antifungal agents such as fluconazole and amphotericine B, but relatively more sensitive to micafungin.