Abstract:

Zheng Wenqian, Sun Yi, Gao Lujuan, Wu Qingzhi, Li Ming, Zeng Tongxiang Yangtze University, Jingzhou 434100, Hubei, China（Zheng WQ）; Department of Dermatology, Jingzhou Central Hospital, The Second Clinical Medical College of Yangtze University, Jingzhou 434100, Hubei, China（Sun Y, Wu QZ, Zeng TX）; Department of Dermatology, Zhongshan Hospital, Fudan University, Shanghai 200032, China（Gao LJ, Li M） Corresponding authors: Gao Lujuan, Email: gao_lujuan@163.com; Sun Yi, Email: jzzxyysy@163.com 【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% （SMIC50） 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.