Gene expression profile analysis of xylitol-sensitive and xylitol-resistant Streptococcus mutans in 0.5% glucose containing TYE media using DNA chip / 대한구강보건학회지

ABSTRACT

OBJECTIVES: Streptococcus mutans (S. mutans) is the major causative bacteria in dental caries. Xylitol is an effective anticarious natural sugar substitute by inhibiting the virulence of S. mutans. However, long-term xylitol consumption leads to the emergence of the xylitol-resistant S. mutans (XR). The aim of this study is to analyze the difference of gene expression profile of xylitol-sensitive S. mutans (XS) and XR in 0.5% glucose containing TYE media, using a DNA chip. METHODS: S. mutans KCTC3065 was maintained in 0.5% glucose and 1% xylitol containing TYE media, during 30 days at 37degrees C 10% CO2 to form XR. The same procedures without xylitol were repeated for the formation of XS. Both XS and XR were cultured in 0.5% glucose with or without 1% xylitol containing TYE media overnight and total RNA was extracted. RNA from XS was labeled with Cy-3 dye as control, and XR were labeled with Cy-5 as references. DNA chip was hybridized for 18-20 h at 42degrees C. RESULTS: A total of 277 genes of DNA chip data were significantly increased or decreased in XR. There is a total of 174 XR up-regulated genes in 0.5% glucose and 1% xylitol containing TYE media, and a total of 103 down-regulated genes. For compare with results of DNA chip, 11 in up-regulated genes and 10 in down-regulated were verified by RT-PCR. The most abundant increased genes in XR were related to cell envelope, cellular processes, DNA metabolism, transcription, and protein folding and stabilization. The decreased genes in XR were related to amino acid biosynthesis, toxin production and resistance, energy metabolism, ribosomal proteins synthesis, and signal transduction. CONCLUSIONS: These results indicate that the difference of gene expression profile of XS and XR may be in existence. In particular, results of this study for XR up-regulated genes have a lot of similarities with the already published xylitol-related researches and other functional studies.