Metagenomics of the circulating blood microbiome and systemic inflammation in preterm infants

项目摘要 循环的人类血液的无菌性一直受到质疑。健康人和老年人的循环血液微生物组 据报道，成人的疾病状态与全身炎症有关，但目前尚无此类数据 早产儿我们的初步数据显示血培养阴性的新生儿的血液 被认为是未感染的，含有微生物DNA，可以被表征为不同的 系统发生群这项研究的假设是， 早产新生儿的循环血液微生物组的组成在感染状态下改变， 如败血症，血液微生物组有助于全身炎症。我们将使用一个整体的，多- 组学方法来测试我们的假设使用2个具体的目标。在具体目标1中，我们将确定微生物 健康早产儿循环血液微生物组（细菌、真菌和病毒）的多样性和组成 新生儿，并将其与培养阳性和培养阴性脓毒症的婴儿进行比较。在我们的第二个具体 目的是，我们建议确定血液微生物组特征与全身性炎症的关联 和新生儿结局。我们的研究将总共招募60名早产儿; 20名培养证实败血症，20名 未患败血症但因败血症症状而进行血培养且结果为阴性的新生儿， 20例无症状早产儿。细菌微生物组将通过宏基因组全鸟枪法进行评估 测序、通过靶向ITS 2区域的真菌微生物组（真菌生物组）和通过已建立的方法的病毒组。凳子 通过16 S rDNA测序评价皮肤拭子，并评价血清中的细胞因子谱。 我们将使用多变量分析来关联微生物负荷、多样性和组成以及细胞因子谱， 临床结果。我们的建议是创新的，因为血液微生物组的存在， 新生儿群体的炎症和结局尚未报告，这将挑战当前的 健康新生儿的无菌血液范例。这项研究的重要性在于，我们将支持 “培养阴性脓毒症”的病理生理学通常与过度使用抗生素有关。通过利用 我们的国家的科学技术，分析工具和技术专长，可在得克萨斯州医疗中心， 我们准备推进我们对血液微生物组和炎症损伤的认识，这可能导致 创新的抗炎疗法在脆弱的早产儿。

PROJECT SUMMARY The sterility of circulating human blood has been questioned. A circulating blood microbiome in healthy and disease states have been reported in adults associated with systemic inflammation but no such data exists in preterm neonates. Our preliminary data shows that the blood of neonates whose blood cultures were negative and who were considered non-infected, contained microbial DNA that can be characterized into distinct phylogenetic groups. The hypothesis of the proposed research is that the microbial diversity and composition of the circulating blood microbiome in preterm neonates is altered in infective states such as sepsis, and the blood microbiome contributes to systemic inflammation. We will use a holistic, multi- omics approach to test our hypothesis using 2 specific aims. In specific aim 1, we will determine the microbial diversity and composition of the circulating blood microbiome (bacterial, fungal and viral) in healthy preterm neonates and compare it with infants with culture-positive and culture-negative sepsis. In our second specific aim, we propose to determine the association of the blood microbiome signatures with systemic inflammation and neonatal outcomes. Our study will enroll a total of 60 preterm neonates; 20 with culture-proven sepsis, 20 neonates who do not have sepsis but have blood cultures drawn for symptoms of sepsis and were negative and 20 asymptomatic preterm neonates. The bacterial microbiome will be evaluated by metagenomic whole shotgun sequencing, fungal microbiome (mycobiome) by targeting ITS2 region and virome by established methods. Stool and skin swabs will be evaluated by 16S rDNA sequencing and cytokines profiles in the serum will be evaluated. We will use multivariable analyses to correlate microbial load, diversity and composition and cytokine profiles to clinical outcomes. Our proposal is innovative in that the presence of the blood microbiome, it’s association with inflammation and outcomes in the neonatal population has not been reported and will challenge the current paradigm of sterile blood in healthy neonates. The significance of the proposed research is that we will underpin the pathophysiology of ‘culture-negative sepsis’ that is often associated with overuse of antibiotics. By utilizing our state-of-the-science technology, analysis tools and technical expertise available at the Texas Medical Center, we are poised to advance our knowledge on the blood microbiome and inflammatory injury, that may lead to innovative anti-inflammatory therapy in vulnerable preterm infants.