汉族与维吾尔族儿童封闭型不同龋敏感中变形链球菌乳酸脱氢酶遗传多态性研究  

Genetic diversity of lactate dehydrogenase of Streptococcus mutans from caries-active vs caries-free individuals in enclosed Uyghur children

作　　者：马丽[1] 林静[1] 李艳[1] 赵今[1] MA Li LIN Jing LI Yan ZHAO Jin(Department of Endodontology, the First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830054, Chin)

机构地区：[1]新疆医科大学第一附属医院牙体牙髓科,新疆乌鲁木齐830054

出　　处：《中国微生态学杂志》2016年第11期1276-1279,共4页Chinese Journal of Microecology

基　　金：国家自然科学基金(81360167)

摘　　要：目的探讨汉族与维吾尔族儿童封闭型不同龋敏感中变形链球菌乳酸脱氢酶活性与ldh基因多态性及龋病发生的关系。方法从前期实验分离的维吾尔族与汉族儿童口腔变形链球菌中筛选出:维吾尔族儿童封闭型口腔变形链球菌高龋组变形链球菌35株[龋失补牙数(dmft)≥5],无龋组变形链球菌37株[龋失补牙数(dmft)=0];27株表现乳酸脱氢酶高活性,24株低活性;汉族儿童口腔中分离的高龋和无龋变形链球菌各35株,高活性和低活性各25株,使用特异引物扩增细菌组DNA,获得结构基因ldh,进行聚合酶链反应-限制性内切酶多态性分析。结果维吾尔族儿童封闭型和汉族儿童MseⅠ酶切ldh-RFLP表现A、B两种基因型;而MnlⅠ、DdeⅠ、NlaⅢ和AluⅠ消化扩增产物未发现多态性。MseⅠ产生的B基因型菌株在维吾尔族儿童封闭型,汉族儿童高龋组的检出均高于无龋组(P<0.05),A、B两种基因型在不同酶活性组的分布不同(P<0.05),高酶活性组B基因型菌株的比例高于低酶活性组;A、B基因型在维吾尔族儿童封闭型和汉族高龋组、无龋组,高酶活性组和低酶活性组的检出比较差异无统计学意义(P>0.05)。结论变形链球菌乳酸脱氢酶基因多态性在维吾尔族与汉族儿童并未表现出差异性,ldh基因多态性与变形链球菌乳酸脱氢酶活性及龋高敏感性相关。ldh基因分布与酶活性及乳牙龋具有正相关性。Objective To study the relationships between LDH activity or genetic diversity and cariogenicity of Streptococcus mutans isolates in enclosed Uyghur children.Methods S.mutans strains were isolated from caries-active and caries-free individuals among 3to 5years old enclosed Uyghur and Han children in Kashi,Xinjiang.There were 35 strains from caries-active enclosed Uyghur children and 37 strains from caries-free ones,among which 27 strains showed high LDH activity while 24 strains showed low LDH activity.35 strains were from caries-active Han children and another 35 strains were from caries-free ones,among which 25 strains showed high LDH activity while 25 strains showed low LDH activity.Then the genetic diversity of PCR products was analyzed by restriction fragment-length polymorphism（RFLP）.Some of the amplified LDH genes from different groups were sequenced and assayed.Results Two genotypes A and B of ldh-RFLP were revealed when the LDH genes were digested with MseⅠ,but the amplified products of ldhgene digested with MnlⅠ,DdeⅠ,NlaⅢand AluⅠ did not show different patterns.The proportion of genotype B strains from caries-active individuals was higher than that from caries-free ones（P〈0.05）,while the distributions of genotypes A and B with different LDH activity were different between two groups（P〈0.05）.The proportion of genotype B strains with LDH activity was higher than those with low activity.Conclusion The LDH gene of S.mutans strains from enclosed Uyghur children is conservative,while there is still the gene mutation.The ldhgenetic diversity may be related to the high caries sensitivity,and very closely correlated with the differences in LDH enzyme activity of S.mutans strains.

关 键 词：变形链球菌 乳酸脱氢酶 酶活性 基因多态性 维吾尔族儿童封闭型 

分 类 号：R378.12[医药卫生—病原生物学]