Deciphering the impact of sedative choice on the dynamics of Klebsiella pneumoniae lung infection

摘要 与医疗保健相关的感染对患者预后产生不利影响，并使医疗成本增加数十亿美元 每年都有几百万美元。麻醉剂的使用会显著增加感染的风险。 免疫信号和免疫效应细胞功能的改变。尽管人们越来越认识到 麻醉药调节免疫，关于其作用机制的广度知之甚少。 针对神经系统的药物会影响宿主的免疫反应。我们之前已经证明过 最常用的麻醉诱导药物异丙酚的短暂镇静显著增加了宿主数量 对微生物感染的敏感性。异丙酚广泛用于需要插管和机械插管的患者 换气，ICU的患者可以用异丙酚镇静数天。为了更好地定义 异丙酚对呼吸系统疾病的镇静作用，我们已经建立了一种小鼠肺部感染的模型，使用的是革兰氏 肺炎克雷伯菌阴性条件致病菌(Kp)。金伯利进程是世界范围内一个日益严重的威胁 院内病原体迅速获得抗菌素耐药性；此外，超强毒力菌株 最近报告了导致社区获得性感染的病例。初步实验表明， 异丙酚镇静显著增加肺内KP病的严重程度，并促进 细菌向远端组织扩散。利用转座子插入测序(INSeq)和Kp文库 插入突变体，我们进一步证明了镇静剂的选择影响Kp的选择 在受感染的肺内生长有缺陷的突变体。这些结果强烈表明异丙酚不是 只影响肺部感染的病理和结局，但它也不同地影响着 疾病所需的细菌毒力因子。因此，这项提案旨在探讨两个相关的和 相互重要的假设是：(1)异丙酚增加宿主对微生物的敏感性(KP) 通过免疫信号的改变干扰先天的募集和功能而引起的肺部感染 免疫效应细胞；以及(2)镇静剂的选择改变了肺环境，影响了Kp 细菌在组织中生长所需的全球毒力谱系。目标1的实验将决定如何 镇静药物的选择影响体内KP肺部感染的转归和进展。AIM 2将在功能上 根据镇静对KP突变体毒力的不同影响对其进行鉴定 异丙酚和氯胺酮/赛拉津。总体而言，这些实验将提供有价值的重要信息 关于镇静对呼吸道感染结局和预后的影响。

Summary Healthcare-associated infections adversely impact patient outcomes and increase healthcare costs by billions of dollars each year. Anesthetic administration is associated with a significantly increased risk of infection via its alterations of immune signaling and immune effector cell function. Despite the increasing recognition that anesthetics modulate immunity, relatively little remains known regarding the breadth of mechanisms by which drugs that target the nervous system influence host immune responses. We have previously demonstrated that brief sedation with propofol, the most commonly used drug for anesthetic induction, dramatically increases host susceptibility to microbial infection. Propofol is widely used for patients requiring intubation and mechanical ventilation, and patients in the ICU can remain sedated with propofol for days. To better define the impact of propofol sedation on respiratory disease, we have developed a mouse model of lung infection using the Gram- negative opportunistic pathogen Klebsiella pneumoniae (Kp). Kp is a growing threat worldwide as a nosocomial pathogen due to its rapid acquisition of antimicrobial resistance; in addition, hypervirulent strains causing community-acquired infections have been recently reported. Preliminary experiments indicate that propofol sedation dramatically increases the severity of Kp disease pathology within the lungs and promotes bacterial dissemination to distal tissues. Using transposon insertion sequencing (INSeq) and libraries of Kp insertion mutants, we have further demonstrated that the choice of sedative influences the selection of Kp mutants that are defective for growth within the infected lung. These results strongly suggest that propofol not only influences the pathology and outcome of lung infection, but that it also differentially impacts the arsenal of bacterial virulence factors required for disease. This proposal is thus designed to explore two related and mutually important hypotheses, those being (1) that propofol increases host susceptibility to microbial (Kp) infection in the lung via alterations in immune signaling that interfere with the recruitment and function of innate immune effector cells; and (2) the choice of sedation alters the lung environment in ways that impact the Kp global virulence repertoire required for bacterial growth in tissues. Aim 1 experiments will determine how sedation choice influences the outcome and progression of Kp lung infection in vivo. Aim 2 will functionally characterize Kp mutants identified based on their virulence being differentially impacted by sedation with propofol versus ketamine/xylazine. Overall, these experiments will provide valuable and important information regarding the impact of sedation on respiratory infection outcome and prognosis.