Probing the impact of polymicrobial interactions on the virulence of an oral pathogen

项目摘要/摘要 牙周炎，或牙周病，在美国影响大约50%的成年人口，可以 导致组织损伤和骨丢失[1，2]。这种疾病的不同寻常之处在于它不是由特定的生物体引起的， 而是一群微生物，包括机会性病原体和共生体[2]。复杂的相互作用 口腔微生物之间的相互影响影响疾病的进展和严重程度，以及对治疗的抵抗力。 [3-7]。在体内研究这些相互作用是具有挑战性的，阻碍了我们理解牙周病的能力。 表征多种微生物相互作用的有效方法包括使用口腔模型 牙周炎的社区和动物模型[5，8-10]。此前，怀特利实验室使用这些方法 确定交叉喂养和交叉呼吸介导的条件致病菌之间的相互作用 Aggregatibacter放线菌(Aa)和口腔共生戈登链球菌(Sg)[6，11，12]。在……里面 此外，这些相互作用增加了AA对先天免疫系统某些成分的抵抗力[8]。在……里面 这项研究的首要假设是代谢相互作用影响口腔中病原体的存活。 空洞。这一建议旨在从两个重要方面扩大我们对口腔多菌相互作用的理解。 首先，它提出了AA和Sg之间的相互作用如何改变AA抵抗先天感染的能力的特征 免疫系统、抗菌化合物和其他口腔微生物的入侵 体外操作和转座子测序(目标1)。第二，本提案旨在使用框架 在表征AA和Sg之间的相互作用方面发展起来，作为识别代谢驱动的模型 AA与多种微生物之间的相互作用(目标2)。相互作用的新陈代谢影响将是 在小鼠脓肿模型的共培养中比较AA适应性所必需的基因 在化学定义的操作中，在体外感染必要的那些。这一目标也将有助于改进 AA基因组的功能注释，以及其他与临床密切相关的潜在基因组 巴氏杆菌科微生物，包括嗜血杆菌。总体而言，拟议的研究将极大地 扩大我们对口腔代谢相互作用如何影响病原体持久性的理解 在牙周炎期间。

PROJECT SUMMARY/ABSTRACT Periodontitis, or gum disease, affects approximately 50% of the adult population in the United States and can result in tissue damage and bone loss [1,2]. This disease is unusual in that it is not caused by a specific organism, but by a consortia of microbes including opportunistic pathogens and commensals [2]. The complex interactions between oral microbes influence the progression and severity of disease, as well as its resistance to treatment [3–7]. Studying these interactions in vivo is challenging, hindering our ability to understand periodontal disease. Productive approaches to characterize polymicrobial interactions have included the use of model oral communities and animal models of periodontitis [5,8–10]. Previously, the Whiteley lab used these approaches to identify cross-feeding and cross-respiration mediated interactions between the opportunistic pathogen Aggregatibacter actinomycetemcomitans (Aa) and the oral commensal Streptococcus gordonii (Sg) [6,11,12]. In addition, these interactions increase Aa’s resistance to certain components of the innate immune system [8]. In this study, the overarching hypothesis is that metabolic interactions impact the survival of pathogens in the oral cavity. This proposal aims to expand our understanding of oral polymicrobial interactions in two significant ways. First, it proposes to characterize how interactions between Aa and Sg alter the ability of Aa to resist the innate immune system, antimicrobial compounds, and the invasion of other oral microbes using a combination of in vitro manipulations and transposon sequencing (Aim 1). Second, this proposal aims to use the framework developed in characterizing the interactions between Aa and Sg as a model to identify metabolically-driven interactions between Aa and a diverse set of microbes (Aim 2). The metabolic impact of interactions will be characterized by comparing the genes necessary for Aa fitness in co-culture in a murine abscess model of infection with those necessary in vitro in chemically defined manipulations. This Aim will also serve to improve the functional annotation of the Aa genome, and potentially genomes of other closely-related clinically relevant microbes in the Pasteurellaceae family, including Haemophilus. Overall, the proposed research will greatly expand our understanding of how metabolic interactions in the oral cavity influence the persistence of pathogens during periodontitis.