Inhibition of In Vitro Biofilm Formation by the Probiotic Yeast CNCM I-745 through Modification of the Extracellular Matrix Composition.

is responsible for post-antibiotic diarrhea and most of the pseudomembranous colitis cases. Multiple recurrences, one of the major challenges faced in infection (CDI) management, can be considered as chronic infections, and the role of biofilm formation in CDI recurrences is now widely considered. Therefore, we explored if the probiotic yeast CNCM I-745 could impact the in vitro formation of biofilm. Biomass staining and viable bacterial cell quantification showed that live exerts an antagonistic effect on the biofilm formation for the three strains tested. Confocal laser scanning microscopy observation revealed a weakening and an average thickness reduction of the biofilm structure when is co-incubated with , compared to the single-species bacterial biofilm structure. These effects, that were not detected with another genetically close yeast, , seemed to require direct contact between the probiotic yeast and the bacterium. Quantification of the extrapolymeric matrix components, as well as results obtained after DNase treatment, revealed a significant decrease of eDNA, an essential structural component of the biofilm matrix, in the dual-species biofilm. This modification could explain the reduced cohesion and robustness of biofilms formed in the presence of CNCM I-745 and be involved in clinical preventive effect against CDI recurrences.