Elucidation of the settling of mutans streptococci to tooth-surface and the distribution using DNA fingerprinting.

本研究的目的是利用染色体DNA指纹图谱(CDF)来验证变形链球菌在日本家庭中的传播情况。从20个家庭(20对已婚夫妇和36名子女)的76名受试者的牙菌斑中培养出1,940株细菌，进行CDF分析，结果鉴定出150株细菌。每个受试者有一个或多个最多四个菌株，每个家庭有两个或两个以上最多八个菌株。在74株儿童中发现的菌株中，33株(44.6%)与母亲相同，23株(31.1%)与父亲共同，2株(2.7%)与父母共同，其余的(21.6%)株与父母不一致。在两个家系中只发现了亲本间的同源毒株。C型占67.3%，d型占12.7%，e型占12.0%，g型占8.0%，c型占48.5%，d、e、g型占87.8%。传播菌表现出比未传播菌更高的不溶性葡聚糖合成活性和疏水性。这些结果表明，变形链球菌不仅可以来自母亲，也可以来自父亲和其他人。这也表明细菌的特性也可能参与了菌株的传播。

The purpose of this study was to demonstrate the transmission of mutans streptococci in Japanese families using chromosomal DNA fingerprinting (CDF). The CDF analysis of 1,940 isolates cultured from the dental plaque of 76 subjects from 20 families (20 married couples and 36 children), resulted in identifying 150 strains. Each subject had one or more up to four strains and each family had two or more up to eight. For the 74 strains found in the children, 33 (44.6%) were common with their mothers, 23 (31.1%) were common with their fathers, 2 (2.7%) were common with both parents, and the remaining (21.6%) strains were not corresponded with both parents. Homological strains between parents were found in only two families. Of the differentiated strains 67.3% were serotype c, 12.7% were d, 12.0% were e, and 8.0% were g. Only 48.5% of serotype c, but 87.8% of serotype d, e, and g were transmitted strains. Transmitted strains showed higher activity levels for insoluble glucan synthesis and hydrophobicities than untransmitted strains. These results indicate that mutans streptococci can be derived not only from the mother but also from the father and other people. It also suggests that bacterial properties may also participate in transmitting strains.