Inhibitory Effect of Sophorolipid on Candida albicans Biofilm Formation and Hyphal Growth

Abstract

Candida albicans causes superficial and life-threatening systemic infections. These are difficult to treat often due to drug resistance, particularly because C. albicans biofilms are inherently resistant to most antifungals. Sophorolipid (SL), a glycolipid biosurfactant, has been shown to have antimicrobial and anticancer properties. In this study, we investigated the effect of SL on C. albicans biofilm formation and preformed biofilms. SL was found to inhibit C. albicans biofilm formation as well as reduce the viability of preformed biofilms. Moreover, SL, when used along with amphotericin B (AmB) or fluconazole (FLZ), was found to act synergistically against biofilm formation and preformed biofilms. Effect of SL on C. albicans biofilm formation was further visualized by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM), which revealed absence of hyphae, typical biofilm architecture and alteration in the morphology of biofilm cells. We also found that SL downregulates the expression of hypha specific genes HWP1, ALS1, ALS3, ECE1 and SAP4, which possibly explains the inhibitory effect of SL on hyphae and biofilm formation.

Anticandidal effect of endophytic bacteria isolated from Equisetum arvense L. against Candida albicans and Candida glabrata

“…Moreover, clinicians have been challenged by the failure of standard antifungal agents. Consequently, there is an urgent requirement for novel anticandidal agents for management of Candida infection 50 . Microbial agents can be an appropriate replacement for artificial fungicides 51 and EB are known to produce various types of active compounds with different biological activities; therefore, they are strong candidates for sources of novel antifungal agents 20 .…”

Microbial biosurfactants: current trends and applications in agricultural and biomedical industries

“…Haque et al . () found the SL derived from S. bombicola MTCC 1910 inhibited C. albicans hyphal growth and biofilm formation as well as reducing the viability of preformed biofilms. SL when used in combination with amphotericin B (AmB) or fluconazole was found to act synergistically against both biofilm formation and preformed biofilm.…”

“…The morphological changes in microbial cells as a result of SL treatment (Haque et al . ) may go some way towards explaining the broad‐spectrum nature of SLs and other biosurfactants (Haque et al . ).…”

“…) may go some way towards explaining the broad‐spectrum nature of SLs and other biosurfactants (Haque et al . ). These changes could be associated with loss of cell membrane integrity resulting in cell death as reported previously for tetracycline‐SL or cefaclor‐SL combination treatment against S. aureus and E. coli respectively (Joshi‐Navare and Prabhune ).…”

“…; Haque et al . ). In a microbiological context, there is a particular interest in those biosurfactants produced by bacteria and their antibacterial, antifungal and antiviral properties.…”