Gut pathogen virulence and its therapeutic modulation during surgical injury

1与多重耐药（MDR）医疗获得性病原体相关的危及生命的感染 2（HAP）导致败血症和多器官衰竭是最致命的，致残和昂贵的并发症面临的 今天有3名危重病人和伤员。随着早期损伤护理的进步，我们现在正在目睹一个新的 4威胁，迟发性脓毒症-今天最常见的死亡原因后，大手术，创伤和烧伤 5伤。虽然肯定需要更新和更强大的抗生素，但部署广泛的“杀死策略”， 6种抗生素带来了破坏肠道微生物组的意外后果， 7抗生素耐药性的出现。在这份提案中，我们提出了令人信服的初步数据，以证明， 8分解代谢损伤本身导致肠道微生物群组成和功能的重大改变， 9对局部和全身免疫力的直接和负面影响。我们第一次证明，正常的 通过粪便微生物群移植（FMT）将10种微生物群作为灌肠剂递送给阴道感染的小鼠，和 11败血症，一个充分表征的多药耐药人类病原体群落（PC），导致他们的完整 12“拯救”否则将是致命的肠源性脓毒症过程。全基因组转录组 对宿主组织（肝、脾、盲肠）的分析表明，FMT诱导了恢复导向的免疫应答。 14、系统层面的应对。最引人注目的是，当这些致命的多重耐药人类病原体 15被腹膜内（IP）引入并且小鼠发展出总体全身性脓毒症，FMT拯救了100%的小鼠， 16健康全基因组测序和基因敲除小鼠的使用提供了关键证据， FMT在两种模型中的作用由系统水平的I型干扰素信号传导介导。因此，在这 我们假设正常的肠道微生物群在肠道疾病中起着关键而未被充分认识的作用。 19严重疾病和感染的结果通过它们对增强病原体的免疫细胞的作用 20个清除机制。在这项提案中，我们将阐明肠道微生物组在肠道疾病中发挥的关键作用。 21免疫清除机制由1.确定粪便微生物群的区域分布和程度 22移植（FMT），以灌肠方式输送，重建肠道微生物组的组成和功能 23在脓毒症小鼠多病原体腹膜炎，2。确定FMT拯救脓毒症的机制 24小鼠腹腔巨噬细胞活化增强治疗多病原菌性腹膜炎 25吞噬功能，和3.阐明了肠道微生物群抑制 26例重大手术损伤后抗生素耐药和致命细菌表型的出现。结果进行 27项拟议的研究有可能改变我们管理重症和受伤患者的方式， 28个战略（即，FMT），其将肠道微生物群的组成和功能维持到足够的程度 29增强免疫功能，降低多药耐药感染、迟发性脓毒症和总体 30例死亡。

1 Life-threatening infections associated with multi-drug resistant (MDR) healthcare acquired pathogens 2 (HAPs) leading to sepsis and multiple organ failure are the most deadly, disabling and costly complications facing 3 the critically ill and injured today. As advances in early injury care have improved, we are now witnessing a new 4 threat, late onset sepsis- today the most common cause of deaths following major surgery, trauma and burn 5 injury. While newer and more powerful antibiotics are certainly needed, deploying a broad “kill strategy” with 6 antibiotics carries the unintended consequence of disruption of the intestinal microbiome and the further 7 emergence of antibiotic resistance. In this proposal we present compelling preliminary data to demonstrate that 8 catabolic injury itself results in a major alteration in intestinal microbiota composition and function which has a 9 direct and negative impact on local and systemic immunity. We show, for the first time, that provision of normal 10 microbiota via fecal microbiota transplant (FMT), delivered as an enema to mice intestinally infected with, and 11 septic from, a well characterized multi-drug resistant human pathogen community (PC), results in their complete 12 “rescue” from what would otherwise be a fatal course of gut-derived sepsis. Whole genome transcriptome 13 analysis of host tissues (liver, spleen, cecum) demonstrated that the FMT induces a recovery-directed immune 14 response at the systemic level. Most strikingly, when these same lethal multi-drug resistant human pathogens 15 are introduced intraperitoneally (IP) and mice develop gross systemic sepsis, FMT rescues 100% of mice to 16 complete health. Whole genome sequencing and use of knockout mice provide key evidence that the protective 17 effect of FMT in both models is mediated by type I interferon signaling at the systemic level. Therefore in this 18 proposal we hypothesize that the normal intestinal microbiota play a key and underappreciated role in 19 the outcome from critical illness and infection via their action on immune cells that enhance pathogen 20 clearance mechanisms. In this proposal we will elucidate the key role that the intestinal microbiome plays on 21 immune clearance mechanism by 1. determining the regional distribution and degree to which, a fecal microbiota 22 transplant (FMT), delivered as an enema, repopulates the composition and function of the intestinal microbiome 23 in septic mice with multi-pathogen peritonitis, 2. determining the mechanisms by which an FMT rescues septic 24 mice from multi-pathogen bacterial peritonitis via its activation and enhancement of peritoneal macrophage 25 phagocytic function, and 3. elucidating the mechanisms by which the intestinal microbiota suppress the 26 emergence of antibiotic resistant and lethal bacterial phenotypes following major surgical injury. Results of these 27 proposed studies has the potential to transform the way we manage critically ill and injured patients by developing 28 strategies (i.e., FMT) that maintain the composition and function of the intestinal microbiota to a degree sufficient 29 to enhance immune function and decrease the rate of multi-drug resistant infections, late onset sepsis and overall 30 mortality.