Probiotics that moderate pH and antagonize pathogens to promote oral health

摘要/摘要 共生口腔链球菌是定植于软硬生物膜中最丰富的细菌。 人类口腔和鼻咽部许多区域的组织。这些与健康相关的细菌 多种不同的黏附策略，并产生一系列化合物和大分子 病原体的殖民性和致病力。在R01 DE25832的支持下，一个大型共生集合 口腔链球菌已从健康受试者中分离出来，并在表型和基因组上进行了特征分析 可促进口腔和全身健康的特性的水平。在这里，我们建议高度筛选这些 不同菌株结合和降解纯化的SARS-CoV-2表面蛋白并进行干扰的能力 与病毒受体ACE2的CoV-2刺突蛋白结合。然后将使用标准方法来 鉴定介导抑制活性的链球菌基因产物。确定的突变体和过度表达 将利用菌株来确认结果。尽管它不是这一紧急修订申请的重点，但它是 值得注意的是，作为DE25832的一部分，我们开发了一个鼠标模型，在该模型中，我们可以建立各种 口腔中的共生链球菌，然后用病原体挑战共生小鼠(S)。 这样的模型可以适用于活体动物挑战研究。重要的是，新的配方系统 我们的一种共生菌株的交付已经通过国际上的 合作，因此我们处于有利地位，可以迅速将我们的体外发现转化为临床试验 治疗性益生菌干预。

Abstract/Summary Commensal oral streptococci are the most abundant bacteria in the biofilms that colonize the hard and soft tissues of the human oral cavity and many areas of the nasopharynx. These health-associated bacteria employ multiple diverse adhesion strategies and produce a spectrum of compounds and macromolecules that inhibit the colonization and virulence of pathogens. With support from R01 DE25832, a large collection of commensal oral streptococci has been isolated from healthy subjects, then characterized at the phenotypic and genomic levels for properties that may promote oral and systemic health. Here, we propose to screen these highly diverse strains for their ability to bind to and degrade purified SARS-CoV-2 surface proteins and to interfere with CoV-2 Spike protein engagement of the viral receptor, ACE2. Standard methods will then be used to identify the streptococcal gene products that mediate inhibitory activities. Defined mutants and overexpressing strains will be utilized to confirm the results. Though not a focus of this Urgent Revision application, it is noteworthy that, as part of DE25832, we have developed a mouse model in which we can establish various commensal streptococci in the oral cavity, then challenge the commensal-colonized mice with a pathogen(s). Such a model could be adapted to in vivo animal challenge studies. Importantly, novel systems for formulation and delivery of one of our commensal strains have already been optimized through an international collaboration, and thus we are well positioned to rapidly translate our in vitro findings to clinical trials of a therapeutic probiotic intervention.