Figure 1.
Quantification of numbers of dispersed cells from C. albicans biofilms grown in three different media.
C. albicans biofilms were developed in RPMI, YNB and YPD media, and the number of dispersed cells recovered from the biofilms was counted over time. Results shown are expressed as mean and standard deviation from three independent experiments for each condition.
Figure 2.
Effect of carbon source on C. albicans biofilm dispersion.
Biofilms were developed for 24 h in YNB medium with 50 mM glucose. The media was then changed to YNB containing varying concentrations of glucose or alternative carbon sources (maltose and galactose). The impact of varying carbon sources and/or concentrations on the level of dispersion was quantified at various time points. Results shown are expressed as mean and standard deviation from two independent experiments for each condition tested.
Figure 3.
Evaluation of the adhesive, biofilm development and invasive properties of dispersed cells.
The adhesive and biofilm-forming properties of planktonic C. albicans yeast cells grown at 37°C, and biofilm dispersed cells were compared in microtiter plate-based adhesion (A) and biofilm development (B) assays using XTT-reduction. Measurement of LDH released from endothelial cells damaged by C. albicans grown under planktonic conditions and by biofilm dispersed cells were expressed as percent cytotoxicity (C).
Figure 4.
Dispersed cells display increased virulence in vivo.
Groups of mice were injected with the same dose (2.8×105 CFU) of either dispersed cells from biofilms (black squares) or cells obtained from matched planktonic cultures (open circles), and their survival was monitored over the course of infection in this murine model of hematogenously disseminated canididiasis. Statistically significant differences were observed between the corresponding survival curves generated for the two groups of mice (P<0.05).
Figure 5.
Regulation of C. albicans biofilm dispersion by UME6.
Biofilms developed by the C. albicans tetO-UME6 strain in the presence (A) and absence (B) of DOX were imaged by SEM. Number of dispersed cells released from biofilms formed by the tetO-UME6 strain in the presence and absence of DOX were enumerated (C) and so was the impact of media switch from + DOX to - DOX and vice versa, on biofilm dispersion (D).
Figure 6.
Regulation of C. albicans biofilm dispersion by PES1.
Biofilms (formed by the C. albicans PES1/PES1 and tetO-PES1 strains) were developed for 17 hours in YNB with DOX, and the number of dispersed cells counted. DOX was withdrawn from the media and number of dispersed cells counted at various time points after antibiotic removal (A). Biofilms formed by the C. albicans PES1/PES1 and tetO-PES1 strains were developed in the presence of DOX (B and C respectively). Impact of change DOX withdrawal on the tetO-PES1 biofilm is shown in panel D. Panel E shows the morphology of the cells in a crack in the tetO-PES1 biofilm developed after removal of the antibiotic from the medium. Since PES1/PES1 showed similar biofilm phenotype before and after media change, only one representative image for both conditions is shown. Scale bar for SEM corresponds to 10 µm for all four images.