中文摘要：

目的探讨不同基因型变形链球菌菌株的致龋特性及其体外成膜规律。方法采用微孔板培养法,对10株不同基因型菌株进行7个不同时间点成膜量的测定。结果 （1）课题小组前期分离获得的5株变链菌临床分离株,除2号菌株外,其余4株的成膜能力检测结果与前期进行的高、低致龋性的鉴定结果一致;（2）携带9号基因型菌株并不是2名儿童高发龋病的直接原因;（3）变形链球菌的体外成膜量在培养16~36 h逐渐增加,36 h达最大值,之后成膜量下降。结论本研究验证了不同基因型变链菌临床分离株的致龋特性,为下一步研究提供了不同致龋特性的可靠菌株;分析携带有相同基因型菌株的2名儿童高发龋病的原因;分析变链菌体外成膜规律,为变链菌致龋特性的研究提供新的依据。

英文摘要：

Objective To explore the cariogenic ability and the rule of biofilm forming of streptococcus mutans strains of different gen-otypes. Methods The microporous plate culture method was adopted to detect the amount of biofilm forming for 10 streptococcus mu-tans strains of different genotypes in seven different periods. Results （1）In addition to strain 2,the abilities of biofilm forming of the other 4 strains were in accordance with the highly or poorly cariogenic abilities. （2）Gene 9 which was carried by both of two children was not the direct reason for their high incidence of caries. （3） The vitro biofilm forming of streptococcus mutans gradually increased from 16 hours to 36 hours,reached the maximum at the 36 hours,then decreased afterwards. Conclusion Through biofilm formation assay,the cariogenic ability of 9 streptococcus mutans is identified clinical isolated strains,which offers reliable strains of different cari-ogenic abilities for further studies. The possible reason for the susceptibility of dental caries in two children who carries the same geno-type is analyzed the rule of biofilm forming of streptococcus mutans,which provides the foundation for further studies on the cariogenic ability of streptococcus mutans.