高龋菌株产生的变链素对口腔链球菌抑制活性的比较

A comparative evaluation on mutacin of Streptococcus mutans isolates from caries-active against Streptococcus oralis

目的通过比较高龋和无龋儿童变形链球菌临床分离株产生的变链素对口腔链球菌的抑制活性,探讨变链素的产生与其致龋性及口腔微生态的关系。方法从10例高龋儿童和10例无龋儿童牙菌斑内分离、鉴定得到80株变形链球菌临床分离株,分为高龋组和无龋组。用平板法检测两组菌株产生的变链素对口腔链球菌Streptococcusoralis ATCC10557的抑制情况,观察两组菌株产生的抑菌环大小,测量记录数据,T检验比较两组菌株抑菌环均数差异。结果高龋组产生的抑菌环平均值为10.4mm,无龋组平均值为6.9mm,T检验显示差异具有显著性(t值为3.098,P<0.05)。结论高龋菌株产生的变链素对ATCC10557有更大的抑制活性,变链素对口腔链球菌的抑制活性与其致龋力呈正相关。

Objective To approach the relationship between mutacin and dental caries and Oral Micro-biosystem by comparing the mutacin activity of Mutans streptococci （MS） isolates from caries-free and caries-active children against Streptococcus oralis. Methods 80 isolated strains were selected and identified from the dental plaque of 10 caries-active （dmft I〉 8 ） and 10 caries-free（ dmft = 0） children, of which the mutacin activity were tested by the stab culture technique a- gainst Streptococcus oralis ATCC 10557. T test was used to analyze the difference in the sizes of inhibition zone between two groups. Results The average inhibition zone sizes of caries-active group was 10.4 mm ,while group of caries-free was 6.9 mm. The difference between the two group was statistically significant （ t = 3. 098, P 〈 0.05 ）. Conclusion The mutacin of MS from caries-active group has greater activity against Streptococcus oralis ATCC 10557. The mutacin activity against Strep- tococcus oralis may present positive correlation with caries-causing tendency.