Sophorolipid, a biosurfactant, inhibits biofilm formation and interacts synergistically with Amphotericin B and Fluconazole on Candida albicans.

Candidiasis is the most common opportunistic infection caused by Candida  species. Despite the use of antifungal therapies, candidiasis is associated with high mortality rate worldwide. An important reason for the failure of current antifungal therapies against candidiasis is attributed to its ability to biofilm formation and its intrinsic antifungals resistance properties. Moreover, only few number of antifungal drugs available for the treatment of candidiasis, which are often limited in their use because of toxicity and severe side effects. Sophorolipid (SL), is a biosurfactant, have antimicrobial and anticancer activity and show meagre cytotoxicity to nrmal human cells. However, their role in inhibition of biofilm formation has been not reported previously. In this study, we tested the in vitro effect of SL on planktonic cells of C. albicans, C. glabrata, C. lusitaniae and C. tropicalis by CLSI method and found to be susceptible to this compound. Consequently, the effect of SL on biofilm formation and on preformed biofilms of C. albicans was assessed. SL inhibits the biofilm formation in a concentration dependent manner and reduces the viability of preformed biofilm. Interaction of SL in with amphotericin B (AmB) or fluconazole (FLZ) was also evaluated on biofilm formation and preformed biofilms of C. albican by checkerboard assay. SL synergistically interacts with AmB or FLZ.