Antagonistic effect of Saccharomyces cerevisiae KTP and Issatchenkia occidentalis ApC on hyphal development and adhesion of Candida albicans

et al. 2019

mBio

Systemic infections of Candida species pose a significant threat to public health. Toxicity associated with current therapies and emergence of resistant strains present major therapeutic challenges. Here, we report exploitation of the probiotic properties of two novel, food-derived yeasts, Saccharomyces cerevisiae (strain KTP) and Issatchenkia occidentalis (strain ApC), as an alternative approach to combat widespread opportunistic fungal infections. Both yeasts inhibit virulence traits such as adhesion, filamentation, and biofilm formation of several non-albicans Candida species, including Candida tropicalis, Candida krusei, Candida glabrata, and Candida parapsilosis as well as the recently identified multidrug-resistant species Candida auris. They inhibit adhesion to abiotic surfaces as well as cultured colon epithelial cells. Furthermore, probiotic treatment blocks the formation of biofilms of individual non-albicans Candida strains as well as mixed-culture biofilms of each non-albicans Candida strain in combination with Candida albicans. The probiotic yeasts attenuated non-albicans Candida infections in a live animal. In vivo studies using Caenorhabditis elegans suggest that exposure to probiotic yeasts protects nematodes from infection with non-albicans Candida strains compared to worms that were not exposed to the probiotic yeasts. Furthermore, application of probiotic yeasts postinfection with non-albicans Candida alleviated pathogenic colonization of the nematode gut. The probiotic properties of these novel yeasts are better than or comparable to those of the commercially available probiotic yeast Saccharomyces boulardii, which was used as a reference strain throughout this study. These results indicate that yeasts derived from food sources could serve as an effective alternative to antifungal therapy against emerging pathogenic Candida species. IMPORTANCE Non-albicans Candida-associated infections have emerged as a major risk factor in the hospitalized and immunecompromised patients. Besides, antifungal-associated complications occur more frequently with these non-albicans Candida species than with C. albicans. Therefore, as an alternative approach to combat these widespread non-albicans Candida-associated infections, here we showed the probiotic effect of two yeasts, Saccharomyces cerevisiae (strain KTP) and Issatchenkia occidentalis (ApC), in preventing adhesion and biofilm formation of five non-albicans Candida strains, Candida tropicalis, Candida krusei, Candida glabrata, Candida parapsilosis, and Candida auris. The result would influence the current trend of the conversion of conventional antimicrobial therapy into beneficial probiotic microbe-associated antimicrobial treatment.

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Probiotic Yeasts Inhibit Virulence of Non -albicans Candida Species

et al. 2019

mBio

“…We and others have observed that beneficial yeast action is dose dependent, where cell density (10 8 /ml) plays a key role in adhesion and hyphal inhibitory ability of Candida species ( 14 , 23 ). Furthermore, heat-killed beneficial yeasts were largely ineffective ( Fig.…”

Section: Resultsmentioning

confidence: 98%

Secondary Metabolites from Food-Derived Yeasts Inhibit Virulence of Candida albicans

et al. 2021

mBio

“…We and others have observed that beneficial yeast action is dose dependent, where cell number (10 8 / ml) plays a key role in adhesion and hyphal inhibitory ability of Candida species (Lohith andAnu-Appaiah, 2018, Kunyeit et al, 2019). Furthermore, heat-killed beneficial yeasts were largely non-functional (Figure supplement 7).…”

Section: Secretome Of Beneficial Yeast Confer Protective Activitymentioning

confidence: 93%

Secondary metabolites from food-derived yeasts inhibit virulence ofCandida albicans

et al. 2020

Preprint

Beneficial microbes in the intestine are thought to control pathogen overgrowth by competing for limited nutrients. Our findings modify this prevailing paradigm of a passive, microbial antagonistic mode of action to an active, directed mechanism mediated by specific secondary metabolites. We describe two food-derived yeasts, Saccharomyces cerevisiae and Issatchenkia occidentalis, that inhibit virulence traits of Candida albicans, including hyphal morphogenesis, biofilms formation and adhesion to intestinal epithelial cells. These yeasts also protect the model host Caenorhabditis elegans from C. albicans infection. We demonstrate that the protective activity is primarily retained in the secretome of the beneficial yeasts and the protection they provide as a physical barrier is minimal. Mutant analysis demonstrates that phenylethanol and tryptophol are necessary for protection and experiments with commercially procured compounds indicates that they are sufficient to inhibit C. albicans virulence. We propose food-derived yeasts as an alternative or combination therapy to conventional antifungal therapy for C. albicans infection.