In vitro antifungal activity of four antifungal agents alone or in combination against Exophiala dermatitidis biofilms / 中华皮肤科杂志

ABSTRACT

Objective To evaluate the in vitro antifungal activity of 4 antifungal agents alone or in combination against Exophiala dermatitidis (E.dermatitidis) biofilms.Methods E.dermatitidis biofilms were prepared by using a modified 96-well plate-based method.The in vitro antifungal activity of amphotericin B,voriconazole,itraconazole and caspofungin alone or in combination against E.dermatitidis biofilms were investigated via the broth microdilution checkerboard technique.Results The sessile minimum inhibitory concentration ranges resulting in 50％ (SMICS0) and 80％ inhibition (SMIC80) of E.dermatitidis biofilms were all ＞ 32 mg/L for itraconazole,voriconazole and caspofungin,and the SMIC50 and SMIC80 ranges of amphotericin B were 1-2 mg/L and 4-8 mg/L respectively.The combination of amphotericin B with voriconazole showed synergistic inhibitory effects against E.dermatitidis biofilms,while the combination of amphotericin B with itraconazole or caspofungin,as well as the combination of voriconazole with caspofungin,revealed no synergistic effects.No antagonistic effect was observed in any of the combinations.Conclusion Amphotericin B appears more active against E.dermatitidis biofilms,and the combination with voriconazole can enhance the anti-biofilm effects against E.dermatitidis biofilms.