[Influence of Streptococcus mutans luxS gene on polysaccharide matrix metabolism]

To investigate the effect of Streptococcus mutans luxS gene on polysaccharide matrix metabolism.

Based on the immobilization of magnetic beads by adherent cells,an assay of biofilm quantitative analysis was developed for the kinetic quantification of biofilm formation. S.mutans luxS gene mutant strain and wild-type strain were compared for their ability of utilizing exogenous carbohydrate to form extracellular polysaccharide matrix. SPSS 10.0 software package was used for statistical analysis. Dunnet t two-side test of one factor analysis of variance was performed.

Both luxS mutant strain and wild-type strain could use exogenous carbohydrate to form polysaccharide matrix.With 1% sucrose added ,both strains completed their biofilm formation within one hour.When adding 1% glucose,these strains also accelerated the formation of biofilm,and this was more significant in the mutant strain.

The luxS gene of S. mutans can regulate its extracellular polysaccharide matrix metabolism. Moreover, the regulation of this gene on biofilm formation is more probably via polysaccharide matrix pathway. Supported by National Natural Science Foundation of China(30872886), Research Fund of Science and Technology Commission of Shanghai Municipality(08DZ2271100),Shanghai Leading Academic Discipline Project(S30206) and Youth Phosphor Program of Science and Technology Commission of Shanghai Municipality (09QA1403700).