Zerumbone Disturbs the Extracellular Matrix of Fluconazole-Resistant Candida albicans Biofilms

This study assessed the effect of zerumbone (ZER) against fluconazole-resistant (CaR) and-susceptible Candida albicans (CaS) biofilms and verified the influence of ZER on extracellular matrix components. Initially, to determine the treatment conditions, the minimum inhibitory concentration (MIC), the minimum fungicidal concentration (MFC) and the survival curve were evaluated. Biofilms were formed for 48 h and exposed to ZER at concentrations of 128 and 256 mu g/mL for 5, 10 and 20 min (n = 12). One group of biofilms did not receive the treatment in order to monitor the effects. The biofilms were evaluated to determine the microbial population (CFU/mL), and the extracellular matrix components (water-soluble polysaccharides (WSP), alkali-soluble polysaccharides (ASPs), proteins and extracellular DNA (eDNA), as well as the biomass (total and insoluble) were quantified. The MIC value of ZER for CaS was 256 mu g/mL, and for CaR, it was 64 mu g/mL. The survival curve and the MFC value coincided for CaS (256 mu g/mL) and CaR (128 mu g/mL). ZER reduced the cellular viability by 38.51% for CaS and by 36.99% for CaR. ZER at 256 mu g/mL also reduced the total biomass (57%), insoluble biomass (45%), WSP (65%), proteins (18%) and eDNA (78%) of CaS biofilms. In addition, a reduction in insoluble biomass (13%), proteins (18%), WSP (65%), ASP (10%) and eDNA (23%) was also observed in the CaR biofilms. ZER was effective against fluconazole-resistant and-susceptible C. albicans biofilms and disturbed the extracellular matrix.

Automated summary

This study assessed the effect of zerumbone on fluconazole-resistant and susceptible Candida albicans biofilms and verified its influence on extracellular matrix components. The results showed that zerumbone had inhibitory effects on biofilms of both fluconazole-resistant and susceptible Candida albicans, and it also disrupted the composition of the extracellular matrix.