A comprehensive investigation of Pseudomonas quorum sensing regulatory relationships and the consequences on quorum sensing inhibitors in complex communities

我们的首要目标是制定有效的战略，以打击多药耐药（MDR）病原体， 日益严重的医疗保健威胁。群体感应（QS）抑制是一种有吸引力的抗微生物方法，因为它 代表了与当前传统疗法根本不同的抗毒力策略。QS a高度 保守的细菌通讯信号调节机制控制许多毒力功能 以及单微生物和多微生物群落中的种间和种内相互作用。不情愿的ESKAPE 病原体铜绿假单胞菌（PA）证实了一种高度成问题的医院病原体， 复杂的相互关联的QS系统控制多种毒力功能并调节拮抗作用， 与其他微生物的协同作用。QS在发病机制中的相关性已经得到承认;然而， 这些系统在感染期间和在多微生物环境中的相互关系已经主要在 体外，在感染期间限制与人类环境的相关性，并回答了基本问题 这将有助于通过利用抗毒力/抗QS方法对抗MDR感染。 我们假设三个QS系统之间的相互关系是 感染严重程度、种间相互作用和微生物群落组成。反过来，我们预计， 抗QS先导化合物将限制感染恶化并促进微生物体内平衡。 我们建议通过利用广泛的PA QS集合来评估这一假设 突变体和一种新的抗QS化合物在动态和人类相关的宿主环境，以确定 特定感染相关的宿主-微生物和微生物-微生物相互作用，并剖析其机制 这些互动的基础。具体而言，在拟议的三个目标中，我们将处理三个基本问题， 将填补现有空白的问题：1）三大PA的监管关系和职能是什么 QS系统？2)抗QS治疗如何影响PA单药治疗中的感染严重程度和QS调节相互作用？ 和多微生物环境中以及3）QS系统和抑制剂如何影响抗性的发展 并限制宿主相关微生物群落的扰动？回答这些问题不仅 为长期存在的关于抗毒力方法和QS作用的问题提供重要见解 PA毒力的突变，但也将揭示体内环境如何影响PA毒力的调控。 三个QS系统的相互关系和依赖QS的种间和种内相互作用。 通过利用新型有效和高度特异性的抗QS化合物进入细菌QS途径，我们的目标是 治疗感染，同时保留微生物群的组成和保护功能。从这些 动态设置可能有助于对抗抗生素耐药性，并提供对抗生素耐药性的基本见解。 复杂感染和体内微生物相互作用的毒力分子机制。

Our overarching goal is to develop efficacious strategies to combat multidrug-resistant (MDR) pathogens, a growing healthcare threat. Quorum sensing (QS) inhibition is an attractive anti-microbial approach, as it represents an anti-virulence strategy fundamentally different from current traditional therapies. QS a highly conserved bacterial communication signaling regulatory mechanism controlling numerous virulence functions and inter- and intraspecies interactions in mono- and polymicrobial communities. The recalcitrant ESKAPE pathogen Pseudomonas aeruginosa (PA) exemplifies a highly problematic nosocomial pathogen with astounding complex interconnected QS systems controlling multiple virulence functions and regulating antagonism or synergism with other microbes. QS relevance in pathogenesis has been recognized; however, the regulatory interrelationships of these systems during infection and in polymicrobial settings have been studied primarily in vitro, limiting relevance to the human environment during infection and leaving answered fundamental questions that will aid in combatting MDR infections by utilizing the anti-virulence/anti-QS approach. We hypothesize that the interrelationships between the three QS systems are significant drivers of infection severity, interspecies interactions, and microbial community composition. In turn, we anticipate that our anti-QS lead compound will restrict infection exacerbations and promote microbial homeostasis. We propose to assess this hypothesis paradigmatically by leveraging an extensive collection of PA QS mutants and a novel anti-QS compound in dynamic and human-relevant host environments to identify specific infection-relevant host-microbe and microbe-microbe interactions and dissect the mechanisms underlying these interactions. Specifically, in the proposed three Aims, we will address three fundamental questions that will fill existing gaps: 1) What are the regulatory relationships and functions of the three major PA QS systems? 2) How do anti-QS therapies impact infection severity and QS regulatory interactions in PA mono- and polymicrobial settings? and 3) How do the QS systems and inhibitors impact the development of resistance and limit perturbations of host-associated microbial communities? Answering these questions will not only provide critical insights into long-standing questions about the anti-virulence approach and the role of QS mutations in PA virulence but will also uncover how the in vivo environment impacts the regulatory interrelationships of the three QS systems and QS-dependent inter- and intraspecies interactions. By tapping into bacterial QS pathways with novel potent and highly specific anti-QS compounds, we aim to treat infections while preserving the composition and protective function of the microbiota. Results from these dynamic settings may aid in the fight against antibiotic resistance and provide fundamental insights into the molecular mechanisms underlying the virulence of complex infections and microbial interactions in vivo.