MICROBIAL ECOLOGY OF PERIODONTAL DISEASES

该项目的长期目标是确定与牙周健康最相容的微生物复合物，从而产生所需菌斑组成的治疗和/或预防策略。具体目标1将检查牙周健康受试者，以确定其龈下菌斑的组成以及菌斑样本中物种之间的联系。这些数据将用于寻找健康受试者之间细菌谱的差异，并检查牙周健康受试者与患有牙周炎和进行牙周维护的受试者之间的差异。在这项横断面研究中，100名牙周健康的受试者将在每颗牙齿的6个牙周部位进行临床评估。牙龈下菌斑样本将分别从每颗牙齿的内侧取出，并使用棋盘DNA-DNA杂交技术分别评估40种细菌的含量。物种从宿主到宿主的传播对它们的口内生存很重要。特异性目标2将确定低水平和患病率的指标受试者的家庭成员是否比高水平和患病率的指标受试者的家庭成员。将选择30名高和30名低红色复合指数受试者，并对其配偶、兄弟姐妹、父母或子女进行临床检查和龈下菌斑组成（如SA1所述）。数据将用于确定低水平或高水平红色复杂物种的定植是否是家庭内的特征。特异性目标3将确定连翘B.，牙龈P.和牙齿T.在家族中是否显示相同的DNA碱基序列选择基因，表明家族内传播。该方法将涉及直接从菌斑样本中选择基因的PCR扩增，然后对产物进行测序。建议的研究将澄清牙周健康受试者牙龈下菌斑的组成，确定是否存在一种或多种健康状况，将健康状况与治疗前后的疾病受试者的状况进行比较，为检查菌斑中重要的细菌关联提供数据基础。确定高水平或低水平的推定致病性红色复合体定殖是否是家族内表现出的一种特征，并确定家族内传播的频率。

The long-term objectives of this Project are to define the microbial complexes that are most compatible with periodontal health leading to therapeutic and/or preventive strategies to produce the desired plaque composition Specific Aim 1 will examine periodontally health subjects in order to determine the composition of their subgingival plaque and the associations among species within the plaque samples. The data will be used to seek differences in bacterial profiles among health subjects and examine differences between periodontally healthy subjects and subjects who have periodontitis and who are on periodontal maintenance. In this cross- sectional study, 100 periodontally healthy subjects will be assessed clinically at 6 periodontal sites per tooth. Subgingival plaque samples will be take separately from the mesial aspect of each tooth and evaluated individually for their content on 40 bacterial species using checkerboard DNA-DNA hybridization. The dissemination of species from host to host is important for their intraoral survival. Specific Aim 2 will determine if family members of index subjects colonized by low levels and prevalence than family members of high-red-complex colonized index subjects. 30 high and 30 low red complex index subjects will be chosen and their spouses, siblings, parents or children examined clinically and for subgingival plaque composition (as described for SA1). Data will be used to determine if colonization by low or high levels of red complex species is a trait within families. Specific Aim 3 will determine if strains of B. forsythus, P. gingivalis and T. denticola in families show identical DNA base sequences for selected genes, suggesting transmission within the family. The method will involve PCR amplification of the chosen gene directly from plaque samples, followed by sequencing of the product. The proposed studies will clarify the composition of subgingival plaque in periodontally healthy subjects, determine if one or more healthy profiles exist, compare healthy profiles to profiles of diseases subjects before and after therapy, provide a data base for examining important bacterial associations in plaque, determine if colonization by high or low levels of the presumed pathogenic red complex is a trait exhibited within families and determine how frequently transmission occurs within families.