CLONAL DIVERSITY OF ORAL PATHOGENS

口腔病原体的克隆多样性

• 批准号: 6489644
• 负责人: Casey CHEN
• 金额: $ 17.92万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-01-01 至 2003-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6489644
• 关键词: Actinobacillus actinomycetemcomitans; Asian Americans; bacterial genetics; clinical research; genetic strain; genotype; gram negative bacteria; host organism interaction; human subject; longitudinal human study; microorganism population study; oral bacteria; periodontitis; serotyping; virulence

Actinobacillus actinomycetemcomitans and Eikenella corrodens are suspected pathogens in periodontitis but both also occur in healthy individuals. This research plan will (1) examine the variabilities of clonal diversity and stability of these organisms within the host, (2) evaluate the synergism between these organisms in localized juvenile periodontitis, and (3) identify pathogenic clones within species. The degrees of clonal diversity of these organisms within the host vary among subjects. Juvenile periodontitis patients harbor greater numbers of distinct E. corrodens clones than healthy subjects; the differences may result from increased susceptibilities of the patients to repeated infections by exogenous clones. Repeated colonization/infection may result in a reduced clonal stability due to replacement of the resident clones by exogenous clones. Colonization/infection by one organism may predispose the host to colonization/infection by the other organism; the relationship is recognized as synergism between the organisms. Within A. actinomycetemcomitans and E. corrodens, strains associated with health may be relatively harmless while others recovered from infections may be more pathogenic. The objectives of this research plan are to: (1) Compare the degrees of clonal diversity, by AP-PCR, of subgingival A. actinomycetemcomitans and E. corrodens in periodontally healthy subjects and localized juvenile periodontitis patients. (2) Examine the clonal stability of subgingival A. actinomycetemcomitans and E. corrodens. Subjects will be sampled again in 9 and 18 months. A quantitative method will be used to assess and compare the clonal stabilities between subject groups. (3) Determine the correlations in the proportional levels or the degrees of clonal diversity between subgingival A. actinomycetemcomitans and E. corrodens. (4) Examine the genetic distinctions between A. actinomycetemcomitans and E. corrodens clones recovered from health and disease by serotyping, AP-PCR genotyping and mutilocus enzyme typing. The study subjects will be limited to Asian-Americans to avoid variations arising from using subjects with different ethnicities, and to examine an ethnic group which is under-represented in previous periodontal disease research. This research plan will provide crucial information regarding the significance of clonal diversity and stability of A. actinomycetemcomitans and E. corrodens in periodontal disease and the synergism between these two organisms, and identify virulent clonal types within these species. The information will be important for the (1) future studies of bacterial virulence factors and (2) prevention and treatment of periodontitis associated with these organisms.

伴生放线杆菌和艾肯氏菌腐蚀性 疑似牙周炎的病原体，但两者也都发生在健康人群中 个人。这项研究计划将(1)检查以下变量 寄主内这些生物的克隆多样性和稳定性，(2) 评价这些微生物在局部性青少年中的协同作用 牙周炎，以及(3)鉴定物种内的致病克隆。这个 这些生物在寄主体内的克隆多样性程度各不相同 在受试者中。青少年牙周炎患者人数更多 与健康受试者相比，截然不同的E.腐蚀克隆；差异 可能是由于患者对反复发作的易感性增加所致 外源克隆的感染。反复定居/感染可能 由于替换驻留对象而导致克隆稳定性降低 通过外源克隆进行克隆。一种生物的定植/感染可能 使寄主易于被另一种生物侵占/感染； 关系被认为是有机体之间的协同作用。在 伴生放线菌和腐蚀性革兰氏杆菌 健康可能相对无害，而其他人则从感染中恢复 可能更具致病性。这项研究计划的目标是： (1)用AP-PCR法比较不同牙周组织克隆多样性程度 牙周健康人群中伴生放线菌和腐蚀菌的研究 受试者和局限性青少年牙周炎患者。(2)审查 伴放线放线菌和E。 腐蚀物。受试者将在9个月和18个月后再次抽样。一个 将采用定量的方法对克隆进行评估和比较 受试组之间的稳定性。(3)确定中的相关性 克隆多样性的比例水平或程度 龈下伴生放线菌和腐蚀菌。(4)审查 伴生放线菌和腐蚀性放线菌的遗传差异 通过血清分型、AP-PCR从健康和疾病中恢复的克隆 基因分型和多位点酶分型。研究对象将是 仅限于亚裔美国人，以避免因使用 不同种族的受试者，并检查一个种族群体 这在以前的牙周病研究中被低估了。 这项研究计划将提供有关 A.A.克隆多样性和稳定性的意义 伴生放线菌和腐蚀性放线菌与牙周病的关系 这两种生物之间的协同作用，并鉴定毒力克隆 这些物种中的类型。这些信息将对 (1)细菌毒力因子的未来研究和(2)预防和 治疗与这些微生物相关的牙周炎。