Lin Jing, Zhao Jin, Nurbiye Munammetemin, Li Xin-shang
Department of Cariology Endodontology and Operative Dentistry, Xinjiang Medical University, Urümqi 830054, China.
Zhonghua Kou Qiang Yi Xue Za Zhi. 2011 May;46(5):267-71.
To investigate the relationship between genotypic diversity of Streptococcus mutans (Sm) and deciduous teeth caries in Xinjiang Uygur autonomous region.
Isolates of Sm were obtained from 17 caries-free and 17 caries-active Uygur preschool children aged from 3 to 5 years. A total of 143 isolates were subcultured, biochemically characterised and identified by polymerase chain reaction (PCR) as Sm and Streptococcus sobrinus (Ss). Then the Sm isolates were genotyped by arbitrarily primed-PCR (AP-PCR).
A total of 81 Sm isolates from caries-active subjects and 62 isolates from caries-free subjects were identified by PCR and forty distinct genotypes identified from 143 clinical isolates. In seventeen caries-active group, 9 children had only 1 genotype, 5 children had 2 genotypes, 3 children had 3 genotypes. In seventeen caries-free group, 14 children had only 1 genotype, 3 children had more than 2 genotypes. The Spearman correlation test showed a strong association between genotypic diversity and caries experience (r = 0.342, P < 0.05).
Isolates of Sm in caries-active Uygur preschool children show apparent more genetic diversity than those in caries-free children. The genotypes of isolates might be related to differences in caries susceptibility.
探讨新疆维吾尔自治区变形链球菌（Sm）基因型多样性与乳牙龋病的关系。
从17名无龋和17名患龋的3至5岁维吾尔族学龄前儿童中分离出变形链球菌。共对143株分离株进行传代培养，通过聚合酶链反应（PCR）进行生化鉴定并鉴定为变形链球菌和远缘链球菌（Ss）。然后通过任意引物PCR（AP-PCR）对变形链球菌分离株进行基因分型。
通过PCR共鉴定出81株来自患龋儿童的变形链球菌分离株和62株来自无龋儿童的分离株，从143株临床分离株中鉴定出40种不同的基因型。在17名患龋组儿童中，9名儿童只有1种基因型，5名儿童有2种基因型，3名儿童有3种基因型。在17名无龋组儿童中，14名儿童只有1种基因型，3名儿童有2种以上基因型。Spearman相关性检验显示基因型多样性与患龋经历之间存在强关联（r = 0.342，P < 0.05）。
患龋的维吾尔族学龄前儿童的变形链球菌分离株比无龋儿童的分离株表现出明显更多的遗传多样性。分离株的基因型可能与龋易感性差异有关。
