Resumo

The adhesion of Candida albicans to the host´s mucosal surface is a major determinant of successful microbial colonization and subsequent infection, and its critical role in the pathogenesis of many infections and fungemia in an immuno-compromised patient. Thus, control of infections caused by yeasts requires strategies that combine the use of antifungal agents with substances that block the adhesion to host cells. Biosurfactants are surface-active compounds (SACs) produced by a wide variety of microorganisms having potential application in medicine. There are many complex molecules, e.g. glycolipids, lipopeptides, and lipopolysaccharides. Several biosurfactants have strong antibacterial, antifungal and antiviral activity, and can be spontaneously adsorbed to surfaces. The interaction of biosurfactants with a substratum surface interferes in the microbial adhesion and desorption processes. This report investigated the effects of the glycolipid-type polymeric biosurfactant produced by Trichosporon montevideense CLOA72 on cells of C. albicans during adhesion to human buccal epithelial cells. Also, we studied interaction with electrostatic charge of C. albicans cells (zeta potential measurements) and cellular hydrophobicity in the presence of biosurfactant. The adhesion of yeasts was reduced up to 87.4% with use of biosurfactant at 16 mg/ml concentration. It has been suggested that the interaction with the cell surface could ultimately be responsible for these actions. Therefore, the electrical interaction of the surface C. albicans cells with the biosurfactant was determined by measurements of zeta potential (ZP). The ZP of the cell surface was monitored as a function of the biosurfactant concentration added to cell suspension showing partial neutralization of net surface charge, since the value of ZP ranged from -20,1 mV to -8,3 mV during the titration. The changes of cell surface characteristics can contribute to the inhibition of initial adherence of cells of C. albicans in surface. This study suggests a possible application of the referred biosurfactant in inhibiting the adhesion and formation of biofilms on biological surfaces by C. albicans.