Impact of farnesol and Corsodyl® on Candida albicans forming dual biofilm with Streptococcus mutans.

Abstract

This work studied the biofilm formed by Candida albicans and Streptococcus mutans on a hydroxyapatite surface after exposure to the quorum-sensing molecule farnesol (200μM) in comparison with the diluted mouthwash Corsodyl® (0.0001% chlorhexidine digluconate). The cytotoxicity of farnesol was evaluated by Galleria mellonella surviving assay. The viability of biofilm cells after exposure to farnesol and Corsodyl® was determined by colony-forming units. The morphology and structure of a dual-species biofilm was evaluated by scanning electron microscopy. Farnesol did not exhibit a toxic effect on larval survival. While 200μM farnesol effectively reduced the yeast-to-hyphae transition in the dual biofilm, it did not affect the growth of S.mutans. Additionally, despite the presence of farnesol, many blastospores were observed. Corsodyl® reduced S.mutans in the dual biofilm, but did not influence C.albicans. This study showed that 200μM farnesol modulated C.albicans in a dual-species biofilm with S.mutans, but did not exhibit antimicrobial activity against S.mutans. Moreover, it seems that S.mutans provides conditions that support the growth of the yeast form of C.albicans. The mouthwash Corsodyl® reduces S.mutans, but was not effective against C.albicans.