中文摘要：

目的初步筛选高致龋性变异链球菌临床分离株。方法通过检测41株变异链球菌临床分离株的产酸能力、耐酸能力、黏附能力和合成细胞外多糖能力，初步筛选出高致龋性变异链球菌临床分离株。结果不同的变异链球菌临床分离株体外致龋能力不同，其中3株产酸能力、耐酸能力、黏附能力和合成细胞外多糖能力均较高，提示可能为高致龋性变异链球菌临床分离株，另外3株产酸能力、耐酸能力、黏附能力和合成细胞外多糖能力均较低，提示可能为低致龋性变异链球菌临床分离株。结论通过筛选可能获得了高致龋性变异链球菌临床分离株。

英文摘要：

Objective To screen of high cariogenicity Streptococcus rnutans （S. mutons） strains isolated from clinical specimens preliminary. Methods Acidogenicity, aciduricity, extracellular polysaecharide production and adhesion of 41 strains of S. mutans isolated from clinical specimens were investigated to screen high cariogenicity S. mutans strains. Results There were different cariogenicity among 41 strains of S. mutans, in which 3 strains of S. mutans had all high ability to produce extraeellular polysaccharide, adhere to the saliva-coated hydroxyapatite, produce acid and tolerate acid, indicated there were 3 strains with high cariogenicity S. mutans strains isolated from clinical specimens. Another 3 strains of S. mutans with all low ability to produce extracellular polysaccharide, adhere to the saliva-coated hydroxyapatite, produce acid and tolerate acid indicated they were low cariogenicity S. mutans strains isolated from clinical specimens. Conclusion We may have obtained high cariogenicity S. mutans strains isolated from clinical specimens.