자일리톨 처리농도에 따른 자일리톨 감성균주와 내성균주의 gtf 유전자 발현과 부착력 비교

• Published in: 대한구강보건학회지 Vol. 36; no. 2; pp. 91 - 96
• Main Authors: 임상욱, Sang Uk Im, 안서영, Seo Young An, 최연희, Youn Hee Choi, 송근배, Keun Bae Song
• Format: Journal Article
• Language: Korean
• Published: 대한예방치과·구강보건학회 30.06.2012
• Subjects: Adhesive ability; Glucosyltransferase; Streptococcus mutans; Xylitol-resistant; Xylitol-sensitive; 치의학
• ISSN: 1225-388X; 2093-7784

Objectives: Xylitol is an effective anticarious natural sugar substitute, by inhibiting the virulence of Streptococcus mutans (S. mutans). However, long-term xylitol consumption leads to an emergence of the xylitol-resistant (XR) strains. This study aimed to confirm the general characteristics, mRNA expression of gtf genes, and adhesive ability of the xylitol-sensitive (XS) and XR S. mutans, by xylitol-treated concentrations. Methods: S. mutans KCTC3065 was maintained in TYE medium, containing 0.4% glucose with 1% xylitol for 30 days at 37oC, 10% CO2 to form XR strain and the same procedures, without xylitol, were repeated for the formation of XS S. mutans. Both XS and XR were cultured by xylitol-treated concentrations (0%, 0.1% and 1%), then, general characteristics, such as growth and acid production, mRNA expression of gtf genes and adhesive ability were analyzed. Results: Xylitol reduced the cell growth of XS S. mutans in a dose-dependent manner, but did not reduce the XR. Xylitol inhibited acid production of XS in a dose-dependent manner. However, it did not inhibit that of XR. Xylitol reduced the gtfB and gtfD mRNA expression of the XS S. mutans, which the genes synthesized soluble and insoluble extracellular polysaccharides, but not reduced that of the XR. By a microtiter plate assay, biofilm formation was more reduced in the XR strains, which means biofilm`s adhesive ability of XR S. mutans was lower than that of the XS. Conclusions: These results indicate that a lower level of adhesive ability for XR S. mutans is related with mRNA expression level of gtf genes, which suggested that the XR strains may be less cariogenic than that of the XS.