Gut pathogen virulence and its therapeutic modulation during surgical injury

1例与多药耐药(MDR)医疗保健获得性病原体相关的危及生命的感染 2(HAPS)导致败血症和多器官功能衰竭是面临的最致命、最致残和最昂贵的并发症 今天有3名重病和伤者。随着早期伤害护理的进步，我们现在正在见证一种新的 4威胁，迟发性脓毒症--今天是大手术、创伤和烧伤后最常见的死亡原因 损伤5例。虽然新的和更强大的抗生素肯定是必要的，但部署广泛的“杀死策略” 6抗生素会带来破坏肠道微生物群的意外后果，并进一步 7出现抗生素耐药。在这项提案中，我们提出了令人信服的初步数据来证明 分解代谢损伤本身会导致肠道微生物区系组成和功能的重大变化，这具有 9对局部和全身免疫的直接和负面影响。我们第一次表明，提供正常的 通过粪便微生物区系移植(FMT)的10个微生物区系，作为肠道感染的小鼠的灌肠，以及 11败血症是一种具有良好特征的多重耐药的人类病原体群落(PC)，其结果是完整的 12从肠源性败血症的致命病程中“拯救”出来。全基因组转录组 13对宿主组织(肝、脾、盲肠)的分析表明，FMT诱导恢复定向免疫 14在系统层面作出反应。最引人注目的是，当这些同样致命的多重抗药性人类病原体 15被腹腔注射(Ip)，小鼠出现全身脓毒症，FMT挽救了100%的小鼠 16完全健康。全基因组测序和使用基因敲除小鼠提供了关键证据，表明 17在两种模型中，FMT的作用都是由系统水平的I型干扰素信号介导的。因此在这件事上 18我们假设正常的肠道微生物区系在肠道疾病中起着关键的、未被认识的作用 19危重疾病和感染通过对增强病原体的免疫细胞的作用而产生的结果 20个清除机构。在这项提案中，我们将阐明肠道微生物群在 21免疫清除机制通过1.确定粪便微生物区系的区域分布和程度 22移植(FMT)，作为灌肠，重新填充肠道微生物组的组成和功能 23多病原性腹膜炎脓毒症小鼠，2.确定FMT抢救败血症的机制 24只小鼠通过激活和增强巨噬细胞防治多病原性细菌性腹膜炎 25吞噬功能，以及3.阐明肠道微生物区系抑制 26大手术损伤后出现抗生素耐药和致死性细菌表型。这些措施的结果 27项拟议研究有可能改变我们处理危重病人和受伤病人的方式，通过开发 28种策略(即FMT)，将肠道微生物区系的组成和功能维持在足够的程度 29增强免疫功能，降低多重耐药感染、迟发性败血症和全身感染 30人死亡。

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.