Domestication and characterization of TM7-the most elusive oral phylum

摘要： 人类微生物组项目提供了相关微生物的全面清单。 与人体的关系。下一个挑战是了解它们在人类健康和疾病中的作用 需要对感兴趣的物种进行栽培。与这一应用相关的，超过一半的口腔 微生物被归类为未培养的系统类型，包括许多与口腔微生物有关的 发病机制。其中，候选科TM7门的成员是最神秘的细菌 口腔中的群组。尽管它们普遍存在于人体部位和其他环境中，但没有 TM7的代表已经被培养成纯文化。作为一个含有可疑病原体的门 与炎症性粘膜疾病，特别是牙周炎有关，培养TM7和 研究它们的致病特性已成为微生物学中的一道“圣杯”。 使用一种新的培养基和增菌技术，我们能够将含有TM7的培养物从 包含疾病相关TM7系统型(TM7x)的复杂群落到双物种共培养 与微小隐杆菌属或非典型韦洛氏菌属为配对菌株。我们假设， TM7x需要特定的合作伙伴物种，了解它们的关系可能是 分离纯化TM7x菌株。此外，TM7x半纯培养的现状和可能 通过本研究获得的纯TM7x培养物将使我们能够研究基因组学， 相互作用与TM7x的致病潜能。这个应用程序旨在测试我们的假设和 通过对TM7x及其合作伙伴之间的关系进行详细的分子分析来实现这些目标 通过对TM7x纯种培养条件的改进，以及对其致病潜力的研究。 这项研究的直接影响是发现了TM7x的培养条件和相关的 生物/生理功能。这项研究的长期意义在于开辟了一条 其他许多尚未培养的潜在致病物种的栽培。

Abstract: The human microbiome project has provided a comprehensive inventory of the microorganisms associated with the human body. The next challenge is to understand their role in human health and disease which requires cultivation of the species of interest. Relevant to this application, more than half of the oral microorganisms are categorized as uncultivated phylotypes including many associated with oral microbial pathogenesis. Among them, members of the candidate division TM7 phylum are the most enigmatic bacterial group in the oral cavity. Despite their ubiquitous occurrence in human body sites and other environments, no TM7 representative has been cultivated as pure culture. As a phylum containing suspected pathogens associated with inflammatory mucosal diseases, particularly periodontitis, cultivation of TM7 and the ability to investigate their pathogenic features has become like a "Holy Grail" in microbiology. Using a novel medium and enrichment techniques, we were able to reduce TM7-containing cultures from a complex community to dual-species co-cultures containing the disease associated TM7 phylotype (TM7x) together with Atopobium parvulum or Veillonella atypica as partner strain. We hypothesize that the growth of TM7x requires specific partner species and that understanding their relationship may be the key for isolating pure culture of TM7x. Furthermore, the present semi-pure cultures of TM7x and the possible pure TM7x cultures obtained through this study will enable our ability to study genomics, interactomics and the pathogenic potential of TM7x. This application aims to test our hypothesis and achieve these goals through detailed molecular analyses of the relationship between TM7x and its partner species, improving the medium for cultivating pure TM7x, as well as exploring its pathogenic potential. The immediate impact of the study is the discovery of cultivation conditions for TM7x and the associated biological/physiological functions. The long-term significance of the study is the creation of a new pathway for cultivation of many other yet-to-be cultured potentially pathogenic species.