Anti-biofilm mechanisms of 3,5-di-tert-butylphenol against clinically relevant fungal pathogens

The methanolic extract (PFME) of Pleurotus florida was assessed for anti-biofilm activity against Candida species. 3,5-Di-tert-butylphenol (3,5-DTB) was identified as the major antifungal constituent in PFME. In its pure form 3,5-DTB inhibits, disrupts, and reduces the viability of biofilm cells as seen from scanning electron and confocal microscopy studies. Microscopic studies and propidium iodide uptake assays confirmed that 3,5-DTB damages the cell membrane of Candida cells. In addition, 3,5-DTB induces accumulation of reactive oxygen species (ROS) which contribute to its pronounced anti-biofilm activity. The results of the present study show that 3,5-DTB exhibits combined anti-biofilm and conventional fungicidal activity against Candida species and elucidate the underlying mechanisms.