FIG 5.

C. albicans microcolony size and density are increased by the addition of S. gordonii cells or S. gordonii supernatants. (A) C. albicans microcolonies were cultured using RPMI 1640 medium at 37°C in 5% CO₂, along with S. gordonii strains CH1, DL1, and SK12; fresh-filtered S. gordonii culture supernatant (10%; sSg); or heat-fixed (HF sSg) S. gordonii culture supernatant (10%) for 17 h. Images were obtained using bright-field microscopy, and the microcolony density was calculated using ImageJ. The addition of S. gordonii or sSg each significantly increased microcolony density compared to C. albicans grown in culture media alone (B, right panel). Microcolony biomass (as determined with crystal violet staining) when grown with HF sSg were significantly increased with S. gordonii strains CH1, DL1, and SK12 (B, right panel). Experiments were carried out in duplicate, and the means ± the SD of four independent experiments are shown. Significance was obtained by one-way ANOVA with post ad hoc Dunnett’s multiple-comparison test (*, P < 0.05; ***, P < 0.001; ****, P < 0.0001). Scale bar, 100 μm.