| Objective: Through comparison Urumqi Uighur different caries sensitive childrendeformation Streptococcus mutants clinical isolates of adhesion and synthesizeexopolysaccharides ability differences, and compare its adhesion related gene spaP-a,spaP-c, spaP-pv, glucose metabolism related genes gtfB, gtfC,Srv+geneticpolymorphisms. Further explore the mechanism of the cariogenic capacity from Uygurhigh caries and caries free children. Methods:1. Using micro plate reader to detect theUyghur’s high caries group (dmft≥5) and caries free group (dmft=0) Streptococcusmutants adhesion on the glass wall in the BHI fluid nutrient medium.2. Respectively userestriction end nuclease Hae III and Alu I enzyme segmentation type of Streptococcusmutans surface proteins of group A area, PV area, C end of genes encoding spaP-a, spaP-c,spaP-pv in high adhesion group and the low adhesion group, comparison of variousgenotypes in two groups of bacteria distribution by PCR-RFLP.3. The quantities ofwater-soluble,water-insoluble glucans synthesized by clinical S.mutans biofilm fromdental plaques of children with high dmfs and caries-free were measured using theanthrone method.4. Respectively on the synthesis of water-insoluble dextran higher groupand lower group use restriction endonuclease restriction endonuclease Bsr I, SsP I, Dde Ienzyme segmentation type Streptococcus mutans glucosyltransferase gene encoding gtfB,gtfC, as well as the surface protein of variable region of V gene encoding SrV~+,comparison of various genotypes in two groups of bacteria distribution by PCR-RFLP.Results:1. High caries group Streptococcus mutans to the glass wall adhesion ratio average(33.928.79)%，Higher than the caries free group(27.537.45)%，the differencewas statistically significant(P＜0.05).2.Two different patterns of the spaP-a PCR-RFLPamong strains were revealed when digested with HaeIII.The proportions of genotypes ofstrains with different binding abilities were different(P＜0.05). The same genotype of thespaP-c, spaP-pv PCR-RFLP among strains were revealed when digested with AluI.3. Thechildren with high dmft had stronger ability in producing water-insoluble glucans thanthose isolated from the caries-free children(0.33330.0479mg/ml v. s.0.23560.0507mg/ml) the difference was statistically significant(P＜0.05)；Water-insoluble glucans produced by all the clinical isolates is higher than water-solubleglucans (0.33110.0576mg/mlv.s.0.25780.0632mg/ml) and the difference wasstatistically significant(P＜0.05).4. There were three and two different patterns of the gtfBand gtfC PCR-RFLP among strains were revealed when digested with Bsr I and SsP I. Theproportions of genotypes from gtfB gene of strains with different synthesize WIG abilitieswere different(P＜0.05).Four different patterns of the SrV~+PCR-RFLP among strainswere revealed when digested with DdeI.The proportions of genotypes of strains withdifferent synthesize WIG abilities were different(P＜0.05). The sequencing DNA testifiedthat the specific base mutat ion would lead to multiple kind of geno type resulted.Conclusion: The different of Streptococcus mutans’ synthesis of extracellularpolysaccharide and adhesion ability from Uygur children with different cariessusceptibility. SpaP-a, gtfB, SrV~+showed a genetic polymorphism may be the cause oftwo groups of Streptococcus mutants’ adhesion ability and synthesis of extracellularpolysaccharide is one of the causes of difference of ability. For further study of Uygurdifferent caries-susceptible children caries pathogenic difference lays a foundation. |
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