Comparison of the inhibition of Candida spp. biofilm formation by quorum-sensing molecules, farnesol and tyrosol with amphotericin B

Background and Aims: Quorum sensing is a mechanism of cell-to-cell communication for controlling virulence and the biofilm formation of microorganisms. Due to this new treatment requiring approaches for biofilm-related infections, this study aims to examine the biofilm formation properties of both Candida albicans and non-albicans (NAC) strains and to compare the effects of the quorum-sensing molecules (QSMs) farnesol and tyrosol with the widely used antifungal agent amphotericin B with regard to biofilm attachment and biofilm formation.Methods: Biofilm formation of 57 nonrepeat clinical isolates of Candida spp. (36 C. albicans and 21 NAC) was assessed through the crystal violet technique. Farnesol (300 μM), tyrosol (80 μM), and amphotericin B (4 μg/ml) were evaluated against biofilm attachment and biofilm formation (plates incubated 2, 4, 6 and 24 h).Results: All isolates displayed biofilm-forming capabilities. C. albicans demonstrated mostly weak biofilm formation (42.2%), whereas the NAC species showed strong biofilm formation (52.38%). Depending on the stage at which they were added, farnesol and tyrosol significantly inhibited the biofilm formation of C. albicans and NAC species, especially at 6 h, which is the early stage of biofilm development. Unfortunately, QSM activity decreased at 24 h. In addition, amphotericin B showed a stronger inhibitory effect than the QSMs at all time points studied, with up to 60% inhibition being observed.Conclusion: QSMs can significantly inhibit biofilm development in both C. albicans and NAC species depending on the stage when they are added, especially in the early stages of biofilm formation.