Shang Ran, Zou Jing, Zhou Xue-Dong
Key. Laboratory of Oral Biomedical Engineering of Ministry of Education, Sichuan University, Chengdu 610041, China.
Hua Xi Kou Qiang Yi Xue Za Zhi. 2006 Dec;24(6):527-9.
To analyze genotypic diversity of oral Streptococcus mutans (S. mutans) and find out horizontal transmission possibility of the microbe in day-nursery children.
The plaque samples were scratched with sterilized toothpicks from teeth of 32 day-nursery children aged between 3 and 4, then cultured on MSB plates. Clones with representative S. mutans-like were subcultured and identified to species level biochemically. AP-PCR fingerprinting was performed to distinguish genotypic diversity of those isolates. Then S. mutans isolated from different children with very similar amplicon profiles were examined by chromosomal DNA fingerprinting analysis.
S. mutans were isolated in oral cavities of 78.1% children, 100% in caries and 69.6% in caries-free children. A total of 57 genotypes were identified by AP-PCR. More than one amplitypes were identified in 88% of the 25 children with S. mutans colonization. Two pair of children shared common genotypic S. mutans.
There is no evident relation between number of genotype detected and caries. The presence of matching genotypes of S. mutans among day-nursery children suggests the horizontal transmission may exist.
分析口腔变形链球菌（S. mutans）的基因型多样性，探讨该微生物在日托儿童中的水平传播可能性。
用无菌牙签从32名3至4岁日托儿童的牙齿上刮取菌斑样本，然后接种于MSB平板上培养。挑选具有代表性的变形链球菌样克隆进行传代培养，并通过生化方法鉴定到种水平。采用AP-PCR指纹图谱技术区分这些分离株的基因型多样性。然后，对扩增图谱非常相似的不同儿童分离出的变形链球菌进行染色体DNA指纹图谱分析。
78.1%的儿童口腔中分离出变形链球菌，患龋儿童中分离率为100%，无龋儿童中分离率为69.6%。通过AP-PCR共鉴定出57种基因型。在25名有变形链球菌定植的儿童中，88%的儿童鉴定出不止一种扩增型。有两对儿童共享相同基因型的变形链球菌。
检测到的基因型数量与龋齿之间无明显关联。日托儿童中存在匹配基因型的变形链球菌，提示可能存在水平传播。
