奶瓶龋儿童口腔变链菌的研究

目的：研究儿童口腔内的变链菌基因型与奶瓶龋易感性的关系。方法：取20名奶瓶龋及20名无龋儿童牙菌斑及唾液接种于TYCSB培养基计数并筛选MS，采用AP－PCR法鉴定变链菌基因型。结果：奶瓶龋组儿童唾液及菌斑变链菌计数高于无龋组；并且有两种以上基因型变链菌的比例也高于对照组（14／20vs 5/20)。结论：患有奶瓶龋的儿童不仅变链菌计数高，而且多数被两个以上基因型的MS感染。

Study of mutans streptococci in children with nursing-bottle caries

AIM: To identify the relationship between the genotype of mutans streptococci and nursing-bottle dental caries in children. METHODS:20 children with nursing-bottle caries were chosen and 20 caries-free children as control. The plaque and saliva were cultivated in the TYCSB medium to isolates and counts the mutans streptococcai. Finally arbitrarily primed polymerase chain reaction(AP-PCR) was used to distinguish the genotype of the mutans streptococcai. RESULTS: The children with nursing-bottle caries had higher count of mutans streptococci than that of caries-free children. 14/20 of them with more than one genotype were detected. Only 5/20 of caries-free children harboured more than one genotype. CONCLUSION: Children with nursing-bottle caries were not only infected heavily with MS, but also often coloized with more than one clonal type.