中国茶预防龋病的实验研究

目的探讨茶浸液中氟对变形链球菌(简称变链菌)致龋作用的动物实验研究分析.方法用致龋性食物和茶浸液饲养接种了S.Sobrinus 6715菌株的大鼠磨牙,观察茶浸液对变链菌的生长及致龋作用影响,设龙井茶(B组)、乌龙茶(C组)、涪陵红茶(D组)各实验组与双蒸馏水对照组(A组)比较. 结果实验组与对照组牙菌斑指数和龋蚀指数有显著性差异,组间差异顺序为D组＞C组＞B组＞A组.此抑菌程度与茶氟含量呈正相关关系.结论本文验证了茶饮料的防龋效果及其安全性为氟防龋提供另一条可行途径.

Streptococcus mutans is a common Gram-positive bacterium and plays a significant role in dental caries. Tobacco and/or nicotine have documented effects on S. mutans growth and colonization. Sortase A is used by many Gram-positive bacteria, including S. mutans, to facilitate the insertion of certain cell surface proteins, containing an LPXTGX motif such as antigen I/II. This study examined the effect of nicotine on the function of sortase A to control the physiology and growth of S. mutans using wild-type S. mutans NG8, and its isogenic sortase-defective and-complemented strains. Briefly, the strains were treated with increasing amounts of nicotine in planktonic growth, biofilm metabolism, and sucrose-induced and saliva-induced antigen I/II-dependent biofilm formation assays. The strains exhibited no significant differences with different concentrations of nicotine in planktonic growth assays. However, they had significantly increased (Pf0.05) biofilm metabolic activity (2-to 3-fold increase) as the concentration of nicotine increased. Furthermore, the sortase-defective strain was more sensitive metabolically to nicotine than the wild-type or sortase-complemented strains. All strains had significantly increased sucrose-induced biofilm formation (2-to 3-fold increase) as a result of increasing concentrations of nicotine. However, the sortase-defective strain was not able to make as much sucrose-and saliva-induced biofilm as the wild-type NG8 did with increasing nicotine concentrations. These results indicated that nicotine increased metabolic activity and sucrose-induced biofilm formation. The saliva-induced biofilm formation assay and qPCR data suggested that antigen I/II was upregulated with nicotine but biofilm was not able to be formed as much as wild-type NG8 without functional sortase A.