The influence of farnesol and tyrosol on Candida spp. virulence traits.

INTRODUCTION

Intercellular communication helps regulate the cell density and the virulence traits in yeasts and bacteria. The study aims to identify the effects of quorum sensing molecules (QSMs) like farnesol and tyrosol on Candida spp. virulence traits.

METHODS

The effects of farnesol and tyrosol were studied on the growth rate of Candida albicans, Candida parapsilosis, Candida krusei, Candida auris, and Candida guilliermondii at different time points, on a 48 hours incubation period. The growth rate was assessed spectrophotometrically. The biofilm formation abilities of Candida spp. were assessed by crystal violet staining technique. Moreover, the expression of C. albicans virulence genes (ALS3, HSP70, SAP2) was analyzed as a response to 100 μM farnesol and tyrosol, by RT-PCR.

RESULTS

Generally, farnesol was found to inhibit the growth rate and biofilm formation mostly in non-albicans species, while tyrosol exerted a non-consistent response on the different Candida species. The expression of ALS3 and HSP70 in C. albicans was upregulated by the QSMs.

CONCLUSIONS

Both farnesol and tyrosol are involved in the regulation of Candida spp. virulence mechanisms, dependent on the used concentration and exposure time and in a species-dependent manner.