Environmental Uncultivable Bacteria Model for Understanding Human Periodontitis

描述(申请人提供)：I025是一种新的不可培养的细菌群，与牙周病有关，在工业化世界中，18%的成年人口受到牙周病的影响。既不知道这一组的天然储集层，也不知道它的完全多样性。I025属于候选的TM7门，它首先在包括海水、土壤和活性污泥在内的各种自然环境中被发现，完全由不可培养的物种组成。最近的独立研究已经在健康和疾病个体的人类口腔微生物群落中检测到TM7核糖体DNA(RDNA)基因序列，而I025主要在疾病个体中检测到。环境中的TM7毒株与人类TM7毒株之间的rDNA序列比较表明，其中一些几乎相同，这表明它们即使不是同一物种，也是近亲。我们假设环境中的类I025细菌可以作为更好地理解I025在人类牙周炎中的作用的模型。我们的目标是建立这样的I025模式。然而，对培养的抗药性使TM7物种无法在其rDNA序列之外进行描述，也几乎没有形态特征，尽管它们在人类口腔菌斑中具有长达70？m的明显细丝。上海州立大学的本科生和硕士生将应用现代和高度敏感的独立于培养的分子技术来研究I025类细菌在它们的自然栖息地中的功能。 该项目的具体目标是： 目的1：通过16S rDNA基因的聚合酶链式反应和序列分析，确定TM7的生态位点，并在与人类牙周相关的TM7物种相关的环境样本中表征TM7的多样性。 目的：通过实时荧光定量聚合酶链式反应和荧光原位杂交技术，对与牙周炎相关基因TM7(I025)密切相关的环境TM7进行定量。 目的：通过显微放射自显影和原位杂交相结合的创新方法，在不需要培养的情况下，测量单个细胞对营养物质的摄取，从而表征TM7细胞在自然环境中的代谢功能。 生态环境是许多人类病原体的蓄水池。I025是一种潜在的新出现的人类病原体，一旦确定了它的环境来源和营养需求，我们就可以建立一个模型，更好地了解它在人类中的作用。

DESCRIPTION (provided by applicant): I025, a novel uncultivable bacteria group, has been associated with periodontal disease, which affects 18% of the adult population in the industrialized world. Neither the natural reservoir nor the complete diversity of this group is known. I025 belongs to the candidate phylum TM7, which was first discovered in diverse natural environments including seawater, soil, and activated sludge, and is made entirely of uncultivable species. Recent independent investigations have detected TM7 ribosomal DNA (rDNA) gene sequences in the human oral microbial community of both healthy and diseased individuals, whereas I025 was detected primarily in diseased individuals. rDNA sequence comparison between environmental and human TM7 strains indicate some are nearly identical, suggesting they are close relatives, if not the same species. We hypothesize that an environmental I025-like bacteria can serve as model for better understanding the I025 role in human periodontitis. Our goal is to establish such an I025 model. Resistance to cultivation, however, has kept TM7 species undescribed beyond their rDNA sequence and few morphological features, despite their conspicuous filaments of up to 70 ¿m in length in the human oral plaque. Undergraduate and Master's students at SJSU will apply modern and highly sensitive culture-independent molecular techniques to investigate the function of I025-like bacteria in their natural habitat. The specific aims of this project are: Aim 1: Identify ecological sites with TM7 and then characterize the diversity of TM7 in those environmental samples related to human periodontal-associated TM7 species through PCR amplification of 16S rDNA gene and sequence analysis. Aim 2: Quantify environmental TM7 closely related to the periodontitis-associated TM7 (I025) through real-time quantitative PCR and fluorescence in situ hybridization. Aim 3: Characterize the metabolic function of TM7 cells in their natural environment through innovative methods that combine microautoradiography and in situ hybridization to measure nutrient uptake by single cells, without the need of cultivation. Ecological environments serve as the reservoir for many human pathogens. I025 is a potential emerging human pathogen, and once its environmental source is defined and the nutrient requirements understood, we can proceed to establish a model for better understanding its role in humans.