CLONAL DIVERSITY OF ORAL PATHOGENS

放线共生放线杆菌和腐蚀艾肯氏菌是 牙周炎中的可疑病原体，但两者也发生在健康 个体 本研究计划将（1）研究 这些生物在宿主内的克隆多样性和稳定性，（2） 评估这些生物之间的协同作用，在本地少年 牙周炎，和（3）确定物种内的致病性克隆。 的 这些生物在宿主体内的克隆多样性程度不同 在科目中。青少年牙周炎患者中 不同的E.比健康受试者腐蚀克隆;差异 可能是由于患者对重复的 外源性克隆的感染。 反复定植/感染可能 由于宿主的替换，导致克隆稳定性降低 一个接一个的克隆一种微生物的定殖/感染可能 使宿主易于被其他生物定殖/感染; 这种关系被认为是生物体之间的协同作用。 内 A. actinomycetemcomitans和E.腐蚀菌，与 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。 本研究计划的目标是： (1)应用AP-PCR技术比较龈下组织的克隆多样性程度 A. actinomycetemcomitans和E.腐蚀牙周健康 受试者和局限性青少年牙周炎患者。(2)检查 龈下A. actinomycetemcomitans和E. 腐蚀受试者将在9个月和18个月内再次采样。 一 将使用定量方法来评估和比较克隆 受试者群体之间的稳定性。(3)确定相关性， 克隆多样性的比例水平或程度 龈下动脉actinomycetemcomitans和E.腐蚀(4)检查 A.之间的遗传差异actinomycetemcomitans和E.艾肯菌 通过血清分型，AP-PCR从健康和疾病中回收的克隆 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代表性不足。 该研究计划将提供有关 克隆多样性和稳定性意义。 actinomycetemcomitans和E.牙周病和牙周病的危害 这两种生物之间的协同作用，并确定毒力克隆 在这些物种中。 这些信息对于 (1)细菌毒力因子的未来研究和（2）预防和 治疗与这些生物体相关的牙周炎。

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.