Site-Specific Non-Mutans Streptococci Etiologies of Dental Caries

描述(由申请人提供)：龋齿的微生物病因学仍在继续研究和辩论。虽然变形链球菌被认为是一种重要的致龋性物种，但在缺乏可检测到的变形链球菌水平的情况下，已观察到龋病--甚至严重的龋齿。据推测，主要菌斑定植的链球菌中的某些菌株可能代表了龋齿的另一种病原学。这些菌株被指定为低pH、非变形链球菌(Non-MS)变种。它们比它们物种的典型产酸和耐酸能力要强得多，与它们的酸相关特性相媲美。变种人。一些横断面研究的数据支持低pH值、非多发性硬化症在龋病病因学中的假设作用。在这项应用中，我们建议通过利用一项正在进行的研究爱荷华州氟化物研究进一步测试低pH、非MS菌株在龋病病因学中的潜在作用的假设，该研究从长期登记在研究中的受试者的第二磨牙咬合面收集并储存了特定部位的样本。特别是，我们有来自13岁和17岁受试者体内相同部位的样本。其中一些部位在13岁临床健康后，在17岁时表现出早期腐烂(白斑病变)。我们建议：1)从第二磨牙隐匿性样本中分离出非MS原发定植链球菌菌株，确定这些菌株存在的基因多样性，以及这些菌株与酸相关的表型的多样性；以及2)将酸相关表型与被分离对象的特定部位龋病经历联系起来。研究设计将允许纵向和横断面数据分析，这代表了检验这一重要假设的独特方法。 公共卫生相关性：这项应用建议调查龋齿是否可能由链球菌特有的低pH变种引起，这种变种通常在牙齿上定植，并有助于菌斑形成。我们将从不同年龄收集的特定部位样本中分离出菌株，并将这些菌株的酸性与分离部位的临床状态相关联。

DESCRIPTION (provided by applicant): The microbial etiology of dental caries continues to be researched and debated. While S. mutans is recognized as a prominent cariogenic species, caries - even severe caries - have been observed in the absence of detectable levels of S. mutans. It has been postulated that certain strains among primary plaque- colonizing species of streptococci may represent an alternative etiology of dental decay. These strains have been designated low-pH, non-mutans-streptococci (non-MS) variants. They are significantly more acidogenic and aciduric than is typical for their species and rival the acid-related properties of . mutans. Data from a handful of cross-sectional studies supports the hypothesized role for the low-pH, non-MS in caries etiology. In this application we propose to further test the hypothesis that low-pH, non-MS strains have a potential role in caries etiology by taking advantage of an ongoing study, the Iowa Fluoride Study, that has collected and banked site-specific samples from the occlusal surfaces of second molars from subjects enrolled long-term within the study. In particular, we have samples from identical sites within subjects at ages 13 and 17. Some of these sites show incipient decay (white-spot lesions) at age 17 after being clinically sound at age 13. We propose to: 1) Isolate non-MS strains of primary colonizing streptococci from second molar occulsal samples, determine the diversity of genotypes present, and the diversity of acid-related phenotypes for those strains; and 2) Correlate the acid-related phenotypes with the site-specific caries experience of the subjects from whom they were isolated. The study design will allow longitudinal and cross-sectional data analyses that represent a unique approach to testing this important hypothesis. PUBLIC HEALTH RELEVANCE: This application proposes to investigate whether dental caries may be caused by the presence of unique low-pH variants of streptococcal species that commonly colonize teeth and contribute to plaque formation. We will isolate strains from site-specific samples collected at different ages and correlate the acid properties of those strains with the clinical status of the sites from which they were isolated.