Abstract

This study aimed to evaluate the effect of proteinase K on mature biofilms of dermatophytes, by assays of metabolic activity and biomass. In addition, the proteinase K–terbinafine and proteinase K–griseofulvin interactions against these biofilms were investigated by the checkerboard assay and scanning electron and confocal microscopy. The biofilms exposed to 32 µg ml⁻¹ of proteinase K had lower metabolic activity and biomass, by 39% and 38%, respectively. Drug interactions were synergistic, with proteinase K reducing the minimum inhibitory concentration of antifungals against dermatophyte biofilms at a concentration of 32 µg ml⁻¹ combined with 128–256 µg ml⁻¹ of terbinafine and griseofulvin. Microscopic images showed a reduction in biofilms exposed to proteinase K, proteinase K–terbinafine and proteinase K–griseofulvin combinations. These findings demonstrate that proteinase K has activity against biofilms of dermatophytes, and the interactions of proteinase K with terbinafine and griseofulvin improve the activity of drugs against mature dermatophyte biofilms.

摘要

本研究旨在通过代谢活性和生物量的测定来评估蛋白酶 K 对皮肤癣菌成熟生物膜的影响。此外，通过棋盘分析以及扫描电子和共聚焦显微镜研究了蛋白酶 K-特比萘芬和蛋白酶 K-灰黄霉素对这些生物膜的相互作用。暴露于 32 µg ml ^-1蛋白酶 K 的生物膜具有较低的代谢活性和生物量，分别为 39% 和 38%。^{药物相互作用是协同的，蛋白酶 K 在 32 µg ml -1}和 128-256 µg ml ^-1的浓度下降低了抗真菌剂对皮肤癣菌生物膜的最低抑制浓度特比萘芬和灰黄霉素。显微图像显示暴露于蛋白酶 K、蛋白酶 K-特比萘芬和蛋白酶 K-灰黄霉素组合的生物膜减少。这些发现表明蛋白酶 K 对皮肤癣菌的生物膜具有活性，并且蛋白酶 K 与特比萘芬和灰黄霉素的相互作用提高了药物对成熟皮肤癣菌生物膜的活性。