S. boulardi

The influence Saccharomyces boulardii on virulence factors of Candida albicans

Candida albicansCandida albicans is a dimorphic fungus growing comensally in gastrointestinal tract of healthy humans. It is however responsible for many opportunistic infections, not only minor mucosal lesions but life treatening systemic infections in immunocompromised patients as well. Saccharomyces boulardii is a yeast strain that has been shown to have applications in the prevention and treatment of intestinal infections caused by bacterial pathogens. Wedetermine whether S. boulardii affects the virulence factors of C. albicans. We demonstrate the inhibitory effect of live S. boulardii cells on the filamentation (hyphae and pseudohyphae formation) of C. albicans SC5314 strain proportional to the amount of S. boulardii added. Live S. boulardii and the extract from S. boulardii culture filtrate diminish C. albicans adhesion to and subsequent biofilm formation on polystyrene surfaces under both aerobic and microaerophilic conditions.

We investigated the influence of S. boulardii cells and its culture extract on C. albicans adhesion to Caco-2 and Intestin 407 cell lines. We also tested the proinflammatory IL-1b, IL-6 and IL-8 cytokine expression by C. albicans-infected Caco-2 cells, using real-time RT-PCR.

We found that both S. boulardii and its extract significantly inhibited C. albicans adhesion to epithelial cell lines. The IL-8 gene expression by C. albicans-infected Caco-2 cells was suppressed by the addition of S. boulardii extract. Our results indicate that S. boulardii affects C. albicans adhesion and reduces cytokine mediated inflammatory host response.

Extract prepared from S. boulardii culture filtrate was fractionated and GC-MS analysis showed that the active fraction contained, apart from 2-phenylethanol, caproic, caprylic and capric acid whose presence was confirmed by ESI-MS analysis. The chief compound inhibiting filamentous C. albicans growth comparably to S. boulardii extract was capric acid, which is thus responsible for inhibition of hyphae formation. It also reduced candidal adhesion and biofilm formation.

  • Biosurfactants

    We identified chemical structures of newly isolated biosurfactants which are secreted by Arctic microorganisms. We are investigating their antibacterial, antifungal properties as well as proapoptotic activity. Biosurfactants can be used as an antiseptics.

  • Biogas

    We are investigating and optimizing the efficiency of metanogenesis in bioreactors. We are also testing various substrates (industrial waste) as materials for biogas production. Microorganisms which participate in this process are investigated as e.g. biofilm producers.

  • Bacteriophages

    Bacteriophages or phages are bacterial viruses. We isolated and are now investigating phages which kill Bacillus strains. Beside the basic research, the collection of phages can be used in industry as for example eliminators of infections.

  • Antiseptics

    Fungal infections are difficult to treat because of the small number of effective drugs. Candida albicans resistance depends on the activity of ABC transporters (MDR, CDR). We have investigated strains and methods for finding new antifungal compounds (synthetic and natural) e.g. probiotic yeast Saccharomyces boulardii.