Figure 3
Membrane vesicles released by L. casei BL23 (LC-MVs) inhibit the early stages of biofilm formation without impacting the growth of S. Enteritidis. (a) S. Enteritidis was grown in polystyrene microplates and treated with LC-MVs (0.04 µg/µL) or a control fraction after 0, 4, 8 and 15 h of growth. After 24 h of culture, biofilms were quantified by crystal violet staining. The control corresponds to the fraction collected after carrying out the purification protocol on the culture medium alone (i.e., MRS medium). Results were normalized to the untreated conditions and expressed as a percentage. (b) Comparison of S. Enteritidis growth curves in the absence and in the presence of treatment with LC-MVs (0.04 µg/µL) and the control fraction. (c) The biofilms formed by S. Enteritidis after 24 h of culture in the absence or in the presence of treatment with LC-MVs (0.04 µg/µl) were stained (live/dead; SYTO 9/propidium iodide) and imaged by confocal laser scanning microscopy (CLSM). Green: total biomass. Red: dead cells.
