变形链球菌葡糖基转移酶遗传多态性与龋病发生关系的研究

A Study on the Relationship between Genetic Diversity within Glucosyltransferases of Streptococcus mutatis and Dental Caries

目的:探讨变形链球菌葡糖基转移酶遗传多态性与龋病发生的关系。方法:菌株分别选自本实验室前期工作中分离鉴定的合成水不溶性多糖能力较强和较弱的血清c型变形链球菌临床分离株,提取全菌DNA,经PCR扩增gtfBC(961～5574 bp)后,分别采用限制性内切酶Hinf Ⅰ、Mbo Ⅰ和Taq Ⅰ进行限制性片段长度多态性分析。结果:不同龋敏感人群变形链球菌血清c型临床分离株经Hinf Ⅰ酶切后限制性片段长度多态性分析酶谱出现了差异,有1.9 kb长片段的菌株在高龋组中的比例高于无龋组(P<0.05)。结论:gtf基因型的不同是导致菌株合成水不溶性多糖能力差异的原因之一。

Objective: The purpose of this study was to study the relationship between genetic diversity within glucosyltransferases of Streptococcus mutans and dental caries. Methods: The isolates were collected from patients of the caries-active group harbored the Streptococcus mutans strains producing higher water-insoluble glucans and patients of the caries-free group harbored the strains with lower water-insoluble ones. The gtfBC (961 - 5574 bp) of the DNA from isolates was amplified by polymerase chain reaction (PCR) . Genetic diversity of gtfBC was assessed using restriction fragment-length polymorphism (RFLP) with restriction endonucle-ases: Hinf I ,Mbo I and Taq I .Results: The differences in the gtf PCR-RFLP patterns among strains were revealed when digested with Hinf I . The number of subjects harbored the longest band 1.9 kb pattern in the caries-active group was significantly more than the caries-free group ( P < 0.05) . Conclusion: The genetic diversity within glucosyltransferases of isolated strains might be related to differences in the production of water-insoluble glucans.