FIG 8 .

Representative CSLM images assessing diffusion of fluorescently labeled vancomycin through S. aureus grown with C. albicans or its derived biofilm matrix material or in spent medium. S. aureus biofilms were grown for 24 h with C. albicans or supplemented with 0.5 mg/ml of purified matrix material. S. aureus biofilms were also grown in C. albicans spent culture medium containing secreted matrix components. Biofilms were stained with ConA for biofilm matrix (red) and fluorescent vancomycin compound (cyan). Following a 1-h diffusion, the biofilms were visualized using CSLM. (A) In the S. aureus monospecies biofilms, vancomycin fully penetrated and diffused throughout the biofilm matrix (white; red/cyan merged), reaching the basal layers. (B) In contrast, in mixed biofilms with C. albicans, minimum vancomycin presence or diffusion was seen. (C) Similarly, in biofilms grown with C. albicans matrix material, vancomycin presence was limited to the surface of the biofilm, with no or minimal penetration into the biofilm. (D) In biofilms grown in spent medium, there was limited penetration of vancomycin into the biofilm matrix and diffused vancomycin was present in greatly reduced concentrations.