糖源对变形链球菌产酸致龋的影响研究

Study on acidogenicity of streptococcus mutans isolates cultured with different carbohydrates

目的观察不同糖源对变形链球菌(变链)生长产酸的影响。方法课题组前期分离自不同龋易感者的变链临床株28株,接种于含葡萄糖或蔗糖的TPY培养基中,厌氧培养24h。pH计检测培养前后培养基的pH值,其差值代表变链产酸能力。t检验比较菌株在含不同糖源培养基中生长产酸差异。结果变链在含葡萄糖和蔗糖的培养基中生长产酸能力差异无统计学意义(P>0.05),无龋组菌株在蔗糖培养基中产酸能力显著大于在葡萄糖培养基中(P<0.05)。结论蔗糖对低致龋性变链菌株产酸有影响。

Objectives To evaluate the effect of different carbohydrates in the broth on the acidogenicity of the Streptococcus mutans isolates. Methods Twenty-eight strains of S. mutans （serotype C） were used, acquired from the previous study. The strains were inoculated in TPY broth containing glucose or sucrose, and anaerobicly cultured for 24h. The pH values before inocula- tion and terminal pH values were measured with pH elecotrode,and the ApH values were determined as the acidogenic abilities of the strains. The acidogenicity difference among strains cultured with different carbohydrates was evaluated by t test. Results The acidogenic abilities of the strains were not significantly different when cultured with glucose or sucrose. The strains from caries-free individuals produced more acid when cultured with sucrose than cultured with glucose （P〈0.05）. Conclusion The cariogenic effect of sucrose is more prominent on the strains from caries-free individuals.