EPIDEMIOLOGY OF A ACTINOMYCETEMCOMITANS IN ORAL DISEASE

这是香农奖，为这项研究提供部分支持 项目低于指定研究所的资助范围，但 都处于最优秀的边缘。香农奖旨在 为测试该方法的可行性提供支持；进一步发展 测试和改进研究技术；执行二次分析 可用的数据集；或执行可演示的离散项目 PI的研究能力或为已经 值得称道的申请。以下摘要摘自原文 首席调查员提交的文件。 兼性革兰氏阴性细菌--放线杆菌 伴生放线菌已被认为是一种重要的致病菌。 各种形式的牙周病。这种细菌在人体内的作用 局限性青少年牙周炎(LJP)一直是人们高度关注的主题 调查。最近，分子方法，如DNA 指纹和限制性片段长度多态性(RFLP) 分析已经被用来了解传播和流行病学 在LJP发现了这种细菌。在这个提议中，假设一个子集 伴放线放线杆菌的人类分离株与 LJP都是克隆的，将进行测试。遗传变异性和遗传多样性的研究 伴放线放线菌特定种群的克隆性 促进细菌特定克隆类型的鉴定 有可能是致命的或相对无毒的。这个 该项目的具体目标是：(1)确定遗传变异 放线菌伴生放线菌的自然种群。多位点 酶电泳法与随机扩增聚合酶链式反应 将被用于确定细菌物种的克隆性 来自LJP家族的具有良好特征的临床分离株的收集。 通过这些方法鉴定的克隆系将与基因分型进行比较 以前以RFLP为特征的群体。目标是建立 伴生放线菌的某些克隆类型与 LJP的发病。(2)描述组织中的差异 这些克隆类型成员之间可能的毒力基因。 与疾病和健康牙周相关的伴生放线菌 状态。RFLP分析将被用来确定遗传异质性 在白毒素中操纵子与特定的 疾病和健康病例中的克隆类型。如果是这样的话， 基因表达的差异可能与致病潜能有关 个体克隆体。(3)评估结构中的克隆可变性 放线菌伴生菌的特定细胞表面成分。这个 目的是确定这些克隆类型的A. 与牙周病变相关的伴生放线菌 状态表达独特的脂多糖(LPS)分子物种和 主要的外膜蛋白。我们将特别强调 关于检测主要外膜蛋白的结构差异 这是一种免疫球蛋白Fc受体。无性系差异 这些细胞表面成分，就像白毒素一样，会 支持毒力和无毒的变种或菌株的概念 放线菌伴生菌存在于人类口腔菌群中。因此， 在这项研究中获得的信息将导致确认 细菌“菌株”和产品应作为最 适合研究流行病学、诊断学、 牙周病研究中的致病性和宿主免疫反应。

This is a Shannon Award providing partial support for the research projects that fall short of the assigned institute's funding range but are in the margin of excellence. The Shannon Award is intended to provide support to test the feasibility of the approach; develop further tests and refine research techniques; perform secondary analysis of available data sets; or conduct discrete projects that can demonstrate the PI's research capabilities or lend additional weight to an already meritorious application. The abstract below is taken from the original document submitted by the principal investigator. The facultative gram-negative bacterium, Actinobacillus actinomycetemcomitans, has been recognized as an important pathogen in various forms of periodontal disease. The role of this bacterium in localized juvenile periodontitis (LJP) has been the subject of intense investigation. More recently, molecular approaches such as DNA fingerprinting and restriction fragment length polymorphism (RFLP) analysis have been used to learn about the transmission and epidemiology of this bacterium in LJP. In this proposal, the hypothesis that a subset of human isolates of A. actinomycetemcomitans that are associated with LJP are clonal will be tested. The study of the genetic variability and clonality of defined populations of A. actinomycetemcomitans will facilitate the identification of specific clonal types of the bacterium that have the potential to be virulent or relatively avirulent. The specific aims of the project are: (1) To determine the genetic variation of natural populations of A. actinomycetemcomitans in LJP. Multilocus enzyme electrophoresis and arbitrarily primed polymerase chain reaction will be used to determine the clonality of the bacterial species in a well-characterized collection of clinical isolates from LJP families. Clonal lines identified by these methods will be compared to genotypic groups previously characterized by RFLP. The objective is to establish that certain clonal types of A. actinomycetemcomitans correlate with the onset of LJP. (2) To characterize differences in the organization of putative virulence genes among members of those clonal types of A. actinomycetemcomitans associated with a disease and healthy periodontal status. RFLP analysis will be used to determine if genetic heterogeneity in a leukotoxin operon correlates with the distribution of specific clonal types in cases of disease and health. If this is the case, differences in gene expression can be related to the pathogenic potential of individual clones. (3) To assess clonal variability in the structure of specific cell surface components of A. actinomycetemcomitans. The objective is to determine if those clonal types of A. actinomycetemcomitans that are associated with a diseased periodontal status express unique molecular species of lipopolysaccharide (LPS) and the major outer membrane proteins. Particular emphasis will be placed on detecting structural differences in the major outer membrane protein that functions as an immunoglobulin Fc receptor. Clonal differences in these cell surface components, as in the case of the leukotoxin, would support the concept that virulent and avirulent variants or strains of A. actinomycetemcomitans exist in the human oral flora. Thus, the information obtained in this study will lead to the identification of bacterial "strains" and products that should serve as the most appropriate subjects for studies that focus on epidemiology, diagnostics, pathogenicity and host immune response in periodontal disease research.