维吾尔族不同龋敏感儿童变异链球菌临床分离株gftB、gftC基因遗传多态性研究

Uighur different caries sensitive children streptococcus mutans clinical isolates gftB,gftC genetic polymorphisms research

目的比较维吾尔族高龋和无龋儿童变异链球菌临床分离株葡萄糖基转移酶编码基因gtfB、gtfC基因遗传多态性与其合成水不溶性葡聚糖的关系。方法选取课题组前期实验所得的维吾尔族儿童合成水不溶性葡聚糖(WIG)能力较强的变异链球菌临床株18株和合成能力较弱临床株12株,提取全菌DNA,经PCR扩增gtfB、gtfC后,利用限制性内切酶BsrⅠ、SsPⅠ进行限制性片段长度多态性分析。结果 gtfB、gtfC经BsrⅠ和SsPⅠ酶切后分别表现出三种和两种基因型,gtfB在WIG合成量较高和较低的菌株中分布不同(P<0.05)。结论维吾尔族不同龋敏感儿童变异链球菌临床分离株gtfB基因的遗传多态性可能是其合成水不溶性葡聚糖能力出现差异的因素之一。

Objective To compare the relationships of genetic polymorphism of gftB and gtfC in Streptococcus mutans clinical isolates and their synthesis of WIG in caries-susceptive and caries-free children of Uyghur nationality. Methods Eighteen Streptococcus mutans clinical isolates strong in WIG synthesis and twelve Streptococcus mutans clinical isolates weak in WIG synthesis from children of Uyghur nationality from the previous experiment of the research group are selected to extract whole bacterial DNA. After gtfB and gffC augmentation via PCR, restriction endonucleases Bsr I and SsP I are used to conduct polymorphic analysis on restriction fragment length. Results After digestion of Bsr I and SsP I, gffB and gtfC demonstrate three and two genotypes respectively, and gffB is differently distributed in isolates with a high WIG content and a low WIG content （P〈0.05）. Conclusion The genetic polymorphism of gtfB in Streptococcus mutans clinical isolates in children with a different degree of caries susceptibility of Uyghur nationality may be one of the factors resulting in the difference in its ability to synthesize WIG.