ABSTRACT

The emergence of resistance requires alternative methods to treat Candida albicans infections. We evaluated efficacy of the efflux pump inhibitor (EPI) verapamil (VER) with fluconazole (FLC) against FLC-resistant (CaR) and -susceptible C. albicans (CaS). The susceptibility of both strains to VER and FLC was determined, as well as the synergism of VER with FLC. Experiments were performed in vitro for planktonic cultures and biofilms and in vivo using Galleria mellonella. Larval survival and fungal recovery were evaluated after treatment with VER and FLC. Data were analyzed by analysis of variance and Kaplan-Meier tests. The combination of VER with FLC at sub-lethal concentrations reduced fungal growth. VER inhibited the efflux of rhodamine 123 and showed synergism with FLC against CaR. For biofilms, FLC and VER alone reduced fungal viability. The combination of VER with FLC at sub-lethal concentrations also reduced biofilm viability. In the in vivo assays, VER and FLC used alone or in combination increased the survival of larvae infected with CaR. Reduction of fungal recovery was observed only for larvae infected with CaR and treated with VER with FLC. VER reverted the FLC-resistance of C. albicans. Based on the results obtained, VER reverted the FLC-resistance of C. albicans and showed synergism with FLC against CaR. VER also increased the survival of G. mellonella infected with CaR and reduced the fungal recovery.

摘要

耐药性的出现需要替代方法来治疗白色念珠菌感染。我们评估了外排泵抑制剂 (EPI) 维拉帕米 (VER) 与氟康唑 (FLC) 对 FLC 耐药 (CaR) 和易感白色念珠菌(CaS) 的疗效。确定了两种菌株对 VER 和 FLC 的敏感性，以及 VER 与 FLC 的协同作用。在体外对浮游培养物和生物膜进行了实验，在体内使用了mellonella. 用 VER 和 FLC 治疗后评估幼虫存活率和真菌恢复情况。通过方差分析和 Kaplan-Meier 检验分析数据。VER 与 FLC 在亚致死浓度下的组合减少了真菌的生长。VER 抑制罗丹明 123 的流出并显示出与 FLC 对抗 CaR 的协同作用。对于生物膜，FLC 和 VER 单独降低了真菌的活力。在亚致死浓度下 VER 与 FLC 的组合也降低了生物膜的活力。在体内试验中，单独或联合使用 VER 和 FLC 可增加感染 CaR 的幼虫的存活率。仅对感染了 CaR 并用 FLC 处理的幼虫观察到真菌恢复的减少。VER 恢复了白色念珠菌的 FLC 抗性. 基于获得的结果，VER 恢复了白色念珠菌的 FLC 抗性，并显示出与 FLC 对 CaR 的协同作用。VER 还增加了感染 CaR的G. mellonella 的存活率并降低了真菌的恢复。