title: [In vitro study of the effect of a lactoperoxidase-peroxidase-thiocyanate system with iodine on the cariogenicinity of streptococcus mutans].
abstract: OBJECTIVE
  This study aimed to investigate the effect of a lactoperoxidase-peroxidase-thiocyanate (LPO-H2O-SCN-) system with different concentrations of iodine (I-) on Streptococcus mutans (S. mutans), particularly on various parameters, including growth, adhesion, glucosyltransferase (GTF) enzyme activity, and insoluble exopolysaccharide synthesis.
  
  
  METHODS
  S. mutans ATCC 25175 was used as experimental species. Clonal formation unit (CFU) were counted to investigate the inhibitory effect on bacterial growth. The inhibition rate of bacterial adherence was calculated to analyze the effect on adhesion. Anthrone method was used to determine the content of insoluble exopolysaccharides and the amount of reducing saccharides. GTF activity and enzyme activity were then determined.
  
  
  RESULTS
  The inhibitory ability of the LPO-H2O2-SCN- system with I- on the cariogenicinity of S. mutans was strengthened as I- concentration was increased. At I- concentration > or = 100 micromol x L(-1) the antibacterial effects were significantly increased compared with those of the control group (P < 0.05). At I- concentration > or = 1,000 micromol x L(-1), the antibacterial effects were significantly improved compared with those of the group with SCN-only (P < 0.05). At I- concentration > or = 100 micromol x L(-1), the inhibition rate of bacterial adherence was > 50%; insoluble exopolysaccharide synthesis and GTF enzyme activity were reduced (P < 0.05).
  
  
  CONCLUSIONS
  The antibacterial effects of the LPO-H2O2-I- system were enhanced by adding I- to overcome the antagonistic effect of physiological SCN- concentration. LPO-H2O2-SCN- system with different concentrations of I- showed statistically significant inhibitory effects on growth, adhesion, insoluble exopolysaccharide synthesis, and GTF enzyme activity.
authors.forename: Xuejun
authors.initials: X
authors.lastname: Liu
authors.forename: Yao
authors.initials: Y
authors.lastname: Liu
authors.forename: Jing
authors.initials: J
authors.lastname: Liang
authors.forename: Lu
authors.initials: L
authors.lastname: Shi
authors.forename: Jinpu
authors.initials: J
authors.lastname: Chu
authors.forename: Beilei
authors.initials: B
authors.lastname: Li
mesh_terms: D000900:Anti-Bacterial Agents; D001422:Bacterial Adhesion; D006861:Hydrogen Peroxide; D066298:In Vitro Techniques; D007455:Iodine; D007784:Lactoperoxidase; D010084:Oxidation-Reduction; D013295:Streptococcus mutans; D013861:Thiocyanates
chemical_list: D000900:Anti-Bacterial Agents; D013861:Thiocyanates; D007455:Iodine; D006861:Hydrogen Peroxide; D007784:Lactoperoxidase