不同龋敏感儿童口腔变形链球菌临床分离株的培养及鉴定

Cultivation and identification of clinical isolated strains of streptococcus mutans in oral cavity of children with different caries susceptibilities

目的:研究不同龋敏感儿童口腔变形链球菌的培养及鉴定。方法:随机选取92例3～5岁的高龋、中龋及无龋儿童,用无菌刮匙刮取龋坏附近的菌斑,无龋者刮取咬合面窝沟内以及邻面的菌斑,置于盛有0.5 ml硫乙醇酸盐转送液的EP管中,用液体石蜡20μl覆盖,封口,迅速转运至实验室。所有临床分离株经微量生化板进行鉴定,并用革兰氏染色法镜检,观察细菌形态,菌细胞形态呈短链状、成对状或分散排列。结果:92例合格对象中,最终分离得到变形链球菌的有59例(64.1%),其中高龋者26例(81.0%),中龋者21例(72.0%),无龋者12例(39.0%)。33例未培养出变形链球菌的个体中,有19例是无龋个体,8例是中龋个体,6例是高龋个体。结论:菌斑中变形链球菌的数量与龋病的流行病学关系并不完全存在着因果关系。

Objective：To study the cultivation and identification of streptococcus mutans in oral cavity of children with different caries susceptibilities. Methods：92 children with severe caries,middle caries and without caries were selected randomly,aseptic curettes were used to collect dental plaques near caries cavity;for the children without caries,the dental plaques were collected from pit and fissure of occlusion surface and neighboring area,then the samples were put into EP tubes containing 0.5 ml transport liquid,then they were covered with 20 μl liquid paraffin and transferred to laboratory after sealing.All the clinical isolated strains were identified with micro biochemical plate,microscopy was carried out after Gram staining,the bacterial morphology was observed,the bacteria were short chain-like,and they distributed in pairs or dispersedly. Results：Among 92 qualified cases,streptococcus mutans were isolated from 59 cases（64.1%） finally,including 26 cases（81.0%） with severe caries,21 cases（72.0%） with middle caries and 12 cases（39.0%） without caries.Streptococcus mutans were not isolated from 33 cases,including 19 cases without caries,8 cases with middle caries and 6 cases with severe caries. Conclusion：There is no total causality between the number of streptococcus mutans in plaque and epidemiology of caries.