Evaluation of the relationship between HtrA and streptococcus mutans isolated from the children with different caries experience * / 重庆医学

ABSTRACT

Objective To evaluate the relationship between mRNA and protein expression of HtrA and Streptococcus mutans i-solated from the children with different caries experience and to provide the theoretical and experimental basis on prediction of dent-al caries in deciduous teeth .Methods The strains of Streptococcus mutans isolated from children with different carious experiences in the preliminary experiments were divided into three groupshigh caries-susceptible group ,middle caries-susceptible group ,caries-free group .All strains were reanimated on the agar plate of MS ,and after smear pure culture examination ,typical bacteria were in-cubated in BHI ,then purified nucleic acid and extracted all the RNA of streptococcus mutans by reverse transcription PCR and de-tected it by agarose gel electrophoresis integrality .Synthetic cDNA and take further PCR amplification with cDNA products .Ob-serve records results by Gel imaging system .HtrA of target gene and electrophoresis image were gray scan by Gel quantitative soft-ware Gel-Pro analyzer 4 .0 was used to analyze relative expression value of gene .After purifying protein ,collected total protein of Streptococcus mutans strains by Western Blot method ,then tested the concentration of total protein sample .The results of Chemilu-minescence imaging were scanned into computer by Bio-Rad analyzing system ,calculated the gray value by software Quantity One 4 .4 .0 which showed the relative expression level of protein .Results There were significant differences in HtrA mRNA and protein expression of different Streptococcus mutans isolated from the children with different caries susceptibility .high caries-susceptible group> middle caries-susceptible group> caries-free group (P< 0 .05) .Conclusion There were significant differences in HtrA mRNA and protein expression of different Streptococcus mutans isolated from the children with different caries susceptibility .The higher caries susceptibility the group was ,the more HtrA mRNA and protein the strain express .