Diversity of Lactobacilli Associated with Severe Early Childhood Caries

与严重儿童早期龋齿相关的乳酸菌多样性

• 批准号: 8188057
• 负责人: PAGE W CAUFIELD
• 金额: $ 55.8万
• 依托单位: NEW YORK UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-22 至 2015-07-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8188057
• 关键词: Adherence; Adult; Area; Bacteria; Benchmarking; Carbohydrates; Categories; Characteristics; Child; Code; Collection; Coupled; Databases; Dental; Dental Plaque; Dental caries; Elements; Environment; Food; Functional RNA; Future; Genes; Genetic; Genetic Variation; Genome; Genomic Islands; Genomics; Genotype; Goals; Habitats; Health; High Prevalence; Individual; Lactobacillus; Lesion; Link; Measures; Methods; Microbe; Mobile Genetic Elements; Natural History; Oral cavity; Pathway interactions; Phylogeny; Plasmids; Play; Population; Probiotics; Process; Property; Publications; Risk; Risk Assessment; Role; Saliva; Sampling; Severities; Site; Source; Specificity; Streptococcus mutans; Surveys; Taxonomy; Techniques; Technology; Testing; Virulence; White Spots; base; cariogenic bacteria; cohort; comparative genomics; comparison group; early childhood; genetic element; genome sequencing; insight; meetings; member; next generation; rRNA Genes; reconstruction; trait

DESCRIPTION (provided by applicant): The long-term objective of this application is to uncover the characteristics of a group of bacteria called the lactobacilli (Lb) that play a key role in the progression and severity of dental caries in both children and adults. For almost a century, the link between caries and Lb was known, but further progress in delineating which of the more than 100 species of lactobacilli were responsible for dental caries remained elusive. Recent advances in genetic methods and the publication of a dozen Lb genomes now make it possible to gain important insight into the sub-group of Lb members and the cariogenic traits responsible for caries. These goals will be met by two specific aims. Aim 1 is to conduct a survey of the Lb populations in three groups of children, those with severe early childhood caries (S-ECC) and two comparison groups, a caries free (CF) and a moderately active caries (white spot lesion, WSL) group. We will accomplish these aims by both culture-independent and culture-dependent methods to obtain estimates of abundance and diversity of the Lb populations. We will also identify individual Lb genotypes found in the three groups by AP-PCR. Lb species identification of unique genotypes will be accomplished by 16S rRNA gene sequencing to obtain a collection of isolates that represent the different species/genotypes that characterize the S-ECC, WSL, and CF habitat or niche. Aim 2 is to identify genetic attributes associated with the caries-niche. A combination of whole-genome sequencing and comparative genomics applied to the isolates derived from Aim 1, coupled with non-oral Lb genome sequences available in public and private database, will result in the identification of genetic signatures unique to the caries/caries-free niche. With this information, clinicians will be able to analyze a bacterial sample from the mouth and determine whether the Lb present are cariogenic or not. This, in turn, will give clinicians an estimation of risk for, and severity of, dental caries. An important spin off to these findings will pave the way toward assessing the cariogenic potential of Lb proposed as health-associated probiotics. PUBLIC HEALTH RELEVANCE: Lactobacilli (Lb) share many characteristics of cariogenic bacteria with the mutans streptococci (MS), including a high prevalence in caries lesions and the ability to generate a low pH environment as well as to survive in it. However, little is known about the natural history, diversity, distribution, and sources of specific species of Lb associated with dental caries. Out of the hundreds of Lb species described thus far, only a handful have been consistently found in the oral cavity and, in particular, associated with dental caries. This raises the question about common attributes that may allow these species to thrive in the oral cavity and, more specifically, determine the progress and severity of dental caries. The proposed study will answer those questions using a combination of well- established microbiologic and genotyping techniques, with next-generation sequencing and whole- genome comparison. Future caries risk assessments, therefore, may include not only Lb counts, but also a measure reflecting their cariogenic potential based on the presence/absence of certain species and/or certain caries-specific genetic elements. This can also be used to indicate how well caries lesions have been restored and retentive areas eliminated. Rendering the mouth Lb-free may become a major objective of dental treatment.

描述（由申请人提供）：本申请的长期目标是揭示一组称为乳杆菌（Lb）的细菌的特征，这些细菌在儿童和成人龋齿的进展和严重程度中发挥着关键作用。近世纪以来，龋齿和乳酸菌之间的联系是已知的，但在描绘100多种乳酸杆菌中哪一种是龋齿的原因方面仍然没有取得进一步的进展。遗传学方法的最新进展和十几个Lb基因组的出版，现在使人们有可能获得重要的洞察LB成员的亚组和致龋性状负责龋齿。这些目标将通过两个具体目标实现。目的1是对三组儿童中的Lb人群进行调查，这些儿童患有严重的幼儿龋（S-ECC），两个对照组，无龋（CF）和中度活动性龋（白色斑点病变，WSL）组。我们将通过文化独立和文化依赖的方法来实现这些目标，以获得Lb种群的丰度和多样性的估计。我们还将通过AP-PCR鉴定三组中发现的个体Lb基因型。将通过16 S rRNA基因测序完成独特基因型的Lb种属鉴定，以获得代表不同种属/基因型的分离株集合，这些不同种属/基因型表征S-ECC、WSL和CF生境或生态位。目的2是确定与龋生态位相关的遗传属性。将全基因组测序和比较基因组学应用于来自Aim 1的分离株，再加上公共和私人数据库中提供的非口腔Lb基因组序列，将导致识别龋齿/无龋齿生态位的独特遗传特征。有了这些信息，临床医生将能够分析口腔中的细菌样本，并确定存在的Lb是否是致龋的。反过来，这将使临床医生对龋齿的风险和严重程度进行估计。这些发现的一个重要副产品将为评估Lb作为健康相关益生菌的致龋潜力铺平道路。 公共卫生相关性：乳酸杆菌（Lactobacilli，Lb）与变形链球菌（Mutans Streptocci，MS）具有致龋菌的许多共同特征，包括在龋病中的高患病率、产生低pH环境并在其中生存的能力，但与龋病相关的特定Lb种类的自然历史、多样性、分布和来源却知之甚少。在迄今为止描述的数百种Lb中，只有少数一直在口腔中发现，特别是与龋齿有关。这就提出了一个问题，即可能使这些物种在口腔中茁壮成长的共同属性，更具体地说，决定了龋齿的进展和严重程度。拟议的研究将使用成熟的微生物和基因分型技术，结合下一代测序和全基因组比较来回答这些问题。因此，未来的龋齿风险评估可能不仅包括Lb计数，还包括基于某些物种和/或某些龋齿特异性遗传因子的存在/不存在来反映其致龋潜力的措施。这也可用于指示龋齿病变的恢复情况和保持区域的消除情况。使口腔无Lb可能成为牙科治疗的主要目标。