Proof of Concept: Scardovia wiggsiae is Cariogenic in vivo

描述(由申请人提供)：虽然已经证明双歧杆菌科物种与龋齿密切相关，但关于这些物种的致龋性的信息有限。这项研究项目的长期目标是减少并最终帮助预防幼儿龋齿(ECC)。此R21应用的目的是证明/反驳被检测为与严重ECC显著相关的红景天在体内会致龋齿的概念。中心假说是，威氏链球菌将在体内诱导牙齿脱矿并产生龋齿，要么单独作用，要么与变形链球菌协同作用。这一建议的基本原理是，体内致龋性的证明将证明这种细菌与人类牙齿健康的相关性，以及如果是的话，其致龋性机制的深入研究是合理的。这个应用程序的中心假设和目标的实现将通过以下两个具体目标进行测试。目的1：红景天的体内致龋性。工作假设是，在动物模型系统中，红景天将定植并诱导牙齿脱矿。不同浓度的微生物将被用来接种喂食致龋性饮食的SpragueDawley大鼠。动物将接受威氏链球菌的定植和组织入侵测试，并对龋齿进行评分。目的2：红景天对变形链球菌的体内致龋性。同时被威氏链球菌和变形链球菌定植的儿童与严重的ECC之间存在显著的相关性。工作假说是，威氏链球菌和变形链球菌的组合会比单独的任何一个物种更多地定居并诱导更多的牙齿脱矿。在目标2中，威氏链球菌和变形链球菌单独感染诱发龋病的能力将与在目标1中使用的相同动物模型中威氏链球菌和变形链球菌联合感染的能力进行比较。试验物种定植和组织侵袭，以及龋齿将被检测。目标1的预期结果将是证明一个与严重ECC显著相关的新命名物种的致龋性，以及目标2的预期结果是通过威氏葡萄球菌和变形链球菌的联合感染增强致龋性。Wiggsiae体内致龋性的预期确认将对该领域产生重要的积极影响，因为这将表明需要进一步研究面临龋病风险的不同种群之间的联系，以及决定致龋性的机制(S)，作为未来改进的儿童龋病微生物诊断、风险评估和治疗的基础。提出的这项研究意义重大，因为它有望在R01水平上实现后续的决定性研究，该研究基于Wiggsiae是人类龋病病原体的假设。虽然这一建议源于与严重ECC相关的物种，但该发现将直接应用于成人龋病的研究，包括快速进展的冠状和根部病变。 与公共健康相关：拟议的研究与公共健康相关，因为它将证明或反驳红景天致龋性的概念。如果这种物种被证明是致龋性的，将其作为龋齿的风险指标进行测试将具有公共卫生意义，这将特别有利于患有猖獗/严重ECC的口腔健康差距人群。这项拟议的研究与NIH战略计划(2009-2013年)的优先事项中描述的NIH使命的一部分相关，通过整合分子和临床(体内疾病模型)方法来证明或反驳龋病风险的诊断生物标记物(目标I-1)，并检查可能导致口腔健康不平等的因素(目标IV-1)。

DESCRIPTION (provided by applicant): While it has been demonstrated that Bifidobacteriaceae species are strongly associated with dental caries, there is limited information about cariogenicity of these species. The long-term goal of this research project is to reduce and ultimately help prevent early childhood caries (ECC). The objective of this R21 application is to prove/disprove the concept that Scardovia wiggsiae, which was detected as significantly associated with severe-ECC, is cariogenic in vivo. The central hypothesis is that S. wiggsiae will induce tooth demineralization and produce caries in vivo, acting either acting alone or in synergy with Streptococcus mutans. The rationale for this proposal is that proof of cariogenic potential in vivo would justify in- depth studies of the bacterium's relevance to human dental health, and if so, its cariogenic mechanisms. The central hypothesis and accomplishment of the objective of this application will be tested with the following two specific aims. Aim 1: Cariogenicity of Scardovia wiggsiae in vivo. The working hypothesis is that Scardovia wiggsiae will colonize and induce tooth demineralization in an animal model system. Differing concentrations of the organism will be used to inoculate Sprague Dawley rats fed a cariogenic diet. Animals will be tested for colonization and tissue invasion by S. wiggsiae, and scored for caries. Aim 2: Cariogenicity of Scardovia wiggsiae with S. mutans in vivo. Significant associations between children colonized by both S. wiggsiae and S. mutans and severe-ECC were detected. The working hypothesis is that a combination of S. wiggsiae and S. mutans will colonize and induce more tooth demineralization than either species alone. In Aim 2, the ability for separate infections by S. wiggsiae and S. mutans to induce caries will be compared with a combined S. wiggsiae and S. mutans infection in the same animal model used in Aim 1. Test species colonization and tissue invasion, and dental caries will be assayed. The expected outcomes in Aim 1 will be the demonstration of cariogenicity of a newly named species significantly associated with severe-ECC, and in Aim 2 demonstration of enhanced cariogenicity by the combined infection of S. wiggsiae with S. mutans. The expected confirmation that S. wiggsiae is cario- genic in vivo would have an important positive impact on the field because it would indicate the need for further investigation into the association of the species with diverse populations at risk for caries and determining mechanism(s) of cariogenicity on which to base future improved microbial diagnosis, risk assessment and treatment for early childhood caries. The research proposed is significant because it is expected to enable subsequent definitive studies at the R01 level based on the hypothesis that S. wiggsiae is a caries pathogen in humans. While this proposal stems from species association with severe-ECC, the findings will have direct application for studies of caries in adults including rapidly progressing coronal and root lesions. PUBLIC HEALTH RELEVANCE: The proposed research is relevant to public health because it will prove or disprove the concept that Scardovia wiggsiae is cariogenic. If this species proves to be cariogenic, it would be of public health relevance to test it as a risk indicator for dental caries which would particularly benefit populations with oral health disparities that experience rampant/severe-ECC. The proposed research is relevant to the part of NIH's mission that is described in the priorities of the strategic plan of NIDCR (2009-2013) by integrating a molecular and clinical (in vivo disease model) approach to prove or disprove a diagnostic biomarker for caries risk (Objective I-1), and examining factors that could contribute to oral health inequality (Objective IV-1).