Figure 9.

Spn TIGR4 kills preformed Sau biofilms. Sau was inoculated in microtiter plates containing THY and incubated for 4 h, after which planktonic cells were removed and fresh THY medium was added. Sau biofilms were left uninoculated (Sau) or co-inoculated with Spn strain D39 (Sau/D39) or TIGR4 (Sau/TIGR4) and incubated for 4 h at 37°C. Biofilms (A) or planktonic cells (B) were harvested, serially diluted and plated onto salt mannitol agar plates to obtain bacterial counts. (C) Dilutions were also plated onto blood agar plates with gentamicin to obtain Spn planktonic and biofilm counts. Error bars represent the standard errors of the means calculated using data from at least three independent experiments; the median (cfu/ml) is shown inside bars. Statistical significance (p < 0.05) in comparison to wells inoculated with Sau (^*), Sau/D39 (♦) or D39 (#).