Department of Stomatology, Faculty of Dentistry, Prince of Songkla University, Songkhla, Thailand.
Mol Oral Microbiol. 2010 Apr;25(2):157-64. doi: 10.1111/j.2041-1014.2009.00556.x.
Lactobacilli have been associated with the presence and progression of dental caries. Nevertheless, the relation between certain species or genotypes of Lactobacillus and caries is unclear and there are no data available for the Thai population. This study aimed to examine the distribution of species and genotypes of oral Lactobacillus among children with rather high caries prevalence, and to investigate whether certain species or genotypes were more related to caries activity than others. One hundred and sixty-five children were examined for caries status. Saliva samples were collected and the numbers of lactobacilli were counted. A total of 357 Lactobacillus isolates from 59 children were identified to species level by 16S ribosomal RNA genes polymerase chain reaction (PCR) -restriction fragment length polymorphism and 16S ribosomal RNA gene sequencing. Furthermore, 304 isolates from 56 children were genotyped using arbitrarily primed PCR. Significant correlation was found between levels of lactobacilli and dental caries (P < 0.001). Among the 10 identified species of Lactobacillus, L. salivarius was more prevalent in children with moderate to high caries prevalence compared with children with low caries prevalence, while L. fermentum was the most predominant species in all study groups. Moreover, a genetic heterogeneity of Lactobacillus species was found among the children and those with high caries prevalence tended to be colonized with more than one clonal type. In summary, L. salivarius may be a putative caries pathogen among preschool Thai children.
乳杆菌与龋齿的发生和进展有关。然而，某些乳杆菌物种或基因型与龋齿之间的关系尚不清楚，泰国人群也没有相关数据。本研究旨在检查具有较高龋齿患病率的儿童口腔乳杆菌的物种和基因型分布，并调查某些物种或基因型与龋齿活动的相关性是否大于其他物种或基因型。对 165 名儿童进行了龋齿状况检查。采集唾液样本并计数乳杆菌数量。通过 16S 核糖体 RNA 基因聚合酶链反应（PCR）-限制性片段长度多态性和 16S 核糖体 RNA 基因测序，从 59 名儿童的 357 株乳杆菌分离株鉴定到种水平。此外，对 56 名儿童的 304 株分离株进行了任意引物 PCR 基因分型。乳杆菌水平与龋齿之间存在显著相关性（P<0.001）。在鉴定的 10 种乳杆菌中，L. salivarius 在中高度龋齿患病率儿童中比低龋齿患病率儿童更为普遍，而 L. fermentum 是所有研究组中最主要的物种。此外，儿童中存在乳杆菌物种的遗传异质性，且高龋齿患病率儿童倾向于定植多种克隆类型。综上所述，L. salivarius 可能是泰国学龄前儿童的潜在致龋菌。
