FIG. 2.

Inhibitory effects of pep166-183 on biofilm formation by P. gingivalis ATCC 33277 with various streptococci as determined by CLSM. HI-stained streptococci (5 × 10⁷ CFU/well; red) were inoculated into individual chambers coated with human whole saliva and cultured anaerobically at 37°C for 16 h. FITC-stained P. gingivalis ATCC 33277 (5 × 10⁶ CFU/well; green) was added to the wells in which streptococcal biofilm was observed. The mixtures were incubated anaerobically at 37°C for 24 h and analyzed by CLSM. In experiments evaluating the inhibition of biofilm formation, P. gingivalis ATCC 33277 was preincubated aerobically with pep166-183 or the control peptide at room temperature for 30 min. Magnification, ×40. The following streptococci were tested: S. oralis ATCC 9811 (A), S. oralis ATCC 10557 (B), S. gordonii G9B (C), S. sanguinis ATCC 10556 (D), and S. parasanguinis ATCC 15909 (E). Representative photographs are shown. In each panel, the upper section displays the monospecies streptococcal biofilm, and the lower section displays the biofilm formed by various streptococci and P. gingivalis ATCC 33277. Data are the means and standard errors of results for six fields in CLSM images. *, P < 0.001 for comparison to results obtained for the control peptide; **, volume of streptococci.