Sphingosines affect the adherence of Streptococcus gordonii and Streptococcus sanguinis on hydroxyapatite

Sphingosines affect the adherence of Streptococcus gordonii and Streptococcus sanguinis on hydroxyapatite. Abstract Sphingosines exhibit bactericidal activity on planktonic cells. However, their anti-adherence activity when adsorbed on hydroxyapatite (HA) surfaces is unknown. Therefore this study evaluated the anti-adherence activity of a variety of sphingosines and their derivatives against Streptococcus gordonii and Streptococcus sanguinis. HA discs were treated with sphingosines, and subsequently incubated with S. gordonii or S. sanguinis. The number of surface-adherent bacteria was evaluated by culturing and microscopy. The anti-adherence activity of sphinganine was evaluated on 24 h old biofilms in the presence and absence of sucrose. Among the tested sphingosines, sphinganine inhibited adherence of S. gordonii and S. sanguinis by 80-and 100-fold, respectively. Growth of S. gordonii was inhibited 75-fold in the presence and absence of sucrose, while the growth of S. sanguinis was inhibited only in the absence of sucrose. These results suggest that sphinganine display potential as coating material to prevent biofilm formation on HA.