Differential gbps Expression from Streptococcus mutans under Different Sucrose Concentration

Objective: The gene expression levels of S.mutans virulence factors are associated with its cariogenicity. Some evidences recently indicated that eviroment conditions might influence gene expression. The aim of the present study was to detect the differential expression of gbps gene from S.mutans cultured under different concentration of sucrose and determined the effects of concentration of sucrose on cariogenicity of S.mutans. Material & Methods: 10 experimental S.mutans strains (serotype c) were from our previous clinical isolates. The isolates were inoculated in TPY media with 0.5%,1% or 5% sucrose. The gene chips of S.mutaus were constructed. The gbp A,B,C,D expression levels of experimental strains cultured uneler different sucrose concentration conditions were examined by Taq Man real-time guantitative PCR and gene chip (construction and detection of gene chips were completed by shanhai Biochip Ltd.co.). Results: Taq Man RT-PCR and gene Chip analysis both showed that gbp A,B,C,D expressions were upregulated when cultural sucros concentration increased from 0.5% to 1% and 5%. The levels of gbp C expression of strains cultured under 1% sucrose was significantly higher than that of the strains under 0.5% sucrose (P<0.05); The gbp A,B,C,D expression of strains with strong adherent ability were higher than that of weak adherent ability strains, especially the difference of gbp C,D expression was statistically significant (P<0.05). Conclusion: Sucrose concentration might regulate adherent ability of S.mutans through regulating expression of some adherence-associated genes. (supported by NSFC 30200317)