儿童口腔中变形链球菌传播方式的研究

Transmission way of oral Streptococcus mutans in children

目的通过对婴儿院儿童及其母亲之间、全托儿童之间口腔中变形链球菌（简称变链菌）传播方式的研究,为儿童龋病预防提供新的思路.方法选取四川省实验婴儿院3～4岁的20名非全托儿童及其母亲和24名全托儿童作为研究对象,无菌牙签收集其菌斑样本,MSB培养基中培养48 h,每种表型菌落挑取一个代表株在TPY平板上次代纯培养,经形态学和微量生化鉴定后对分离的变链菌株行AP-PCR扩增,对不同个体出现相似基因型的变链菌株进行分析.结果44名儿童中,65.9%的儿童口腔内检出变链菌,20对母子中有10对均检出变链菌,44名儿童及20名母亲口腔中共分离出98株变链菌;均有变链菌检出的10对母子口腔中分辨出32个不同的基因型,其中7对母子有相似基因型出现;24名全托儿童口腔中共分辨出29个不同的基因型,有2种基因型在13名全托儿童口腔中有重复检出.结论变链菌在婴儿院儿童中存在水平传播及垂直传播两种传播方式.

Objective To find out different transmission ways of oral mutans Streptococci（MS） in nursery children. Methods The study group included 44 nursery children between 3 and 4 years of age and 20 mothers. Dental plaque samples were collected with sterile toothpick and cultured on MSB plates for 48 h. Individual MS colonies representative of the colonial morphologies were subcultured on TPY plates. These strains were biocbemically identified to species level. AP-PCR fingerprinting analysis was preformed after identification. Results MS was isolated in oral cavities of 65.9% children in 44 babies and 50% pairs in 20 mother-child pairs. A total of 98 MS isolates from 44 children and 20 mothers were isolated. Thirty-two different amplitypes were identified in 10 mother-child pairs colonized by MS and there were similar genotypes in 7 pairs of mother-child. Twenty-nine different amplitypes were identified in 24 nursery children, and there were 2 genotypes of MS isolated repeatedly among 13 nursery children. Conclusions The presence of matching genotypes of MS among nursery children and their mothers suggests horizontal and vertical transmission.