Decoding the microbial burden in diabetic foot ulcers

慢性、不愈合的伤口是糖尿病常见且昂贵的并发症。微生物定殖和 假设生物膜形成损害伤口愈合并导致严重的并发症， 骨髓炎和截肢。尽管所有慢性伤口都被微生物群定殖，但其重要性， 目前尚不清楚是否存在临床感染。在这个竞争性的更新中，我们假设主机 反应、伤口愈合和临床DFU结果由以下因素决定：1） 伤口病原体金黄色葡萄球菌; 2）与伤口病原体的体液相互作用;以及3） 与宿主的互动。在上一个周期中，我们开发了一个鸟枪宏基因组 测序管道，以分析定殖神经性、未感染DFU的微生物群（n=100;“DFU 100” 队列）在纵向前瞻性队列研究中。我们观察到伤口的应变水平变化 病原体金黄色葡萄球菌与DFU结果相关。因此，在目标1中，我们将使用 微生物基因组方法和来自DFU 100队列的匹配临床分离株鉴定S.金黄色 DFU发病机制的基因组决定因素及其与临床结局的相关性。我们还观察到 临床上被视为“旁观者”的种属（例如皮肤寄生虫、环境污染物）影响 伤口病原体的毒力和调节宿主组织修复反应以促进体内愈合。目标2将 确定是否一个皮肤寄生虫，棒状杆菌纹状体，调谐的毒力S。金黄色葡萄球菌和改善 小鼠和猪S.金黄色葡萄球菌伤口感染目标3基于我们的观察 粪产碱菌伤口分离物促进角质形成细胞迁移、细胞因子分泌， 糖尿病伤口愈合的鼠模型中的伤口闭合。我们将建立机制和治疗 A的潜力。粪便介导的宿主反应，导致加速伤口愈合。拟议 研究将使用尖端的跨学科方法来调查伤口之间的相互作用， 病原体、伤口“旁观者”和宿主;了解这些机制将有助于改善DFU 我们的长期目标是：1）开发新的基于微生物的干预措施， 利用微生物与彼此和宿主的相互作用的愈合;和2）鉴定微生物生物标志物， 对有并发症风险的患者进行分类。

Chronic, non-healing wounds are common and costly complications of diabetes. Microbial colonization and biofilm formation are hypothesized to impair wound healing and contribute to severe complications such as osteomyelitis and amputation. Although all chronic wounds are colonized with microbiota, its importance, in the absence of clinical infection, is currently unknown. In this competitive renewal, we hypothesize that host response, wound healing, and clinical DFU outcomes are determined by 1) genomic diversification of the wound pathogen Staphylococcus aureus; 2) commensal interactions with wound pathogens; and 3) commensal interactions with the host. In the previous cycle, we developed a shotgun metagenomic sequencing pipeline to analyze the microbiota colonizing neuropathic, non-infected DFU (n=100; the “DFU100” cohort) in a longitudinal prospective cohort study. We observed that strain-level variation of the wound pathogen Staphylococcus aureus was associated with DFU outcomes. Therefore, in Aim 1, we will use a microbial genomic approach and matched clinical isolates from the DFU100 cohort to identify S. aureus genomic determinants of pathogenesis in DFU and their association with clinical outcomes. We also observed that species clinically regarded as “bystanders” (e.g. skin commensals, environmental contaminants) influence the virulence of wound pathogens and tune host tissue repair responses to promote healing in vivo. Aim 2 will determine if a skin commensal, Corynebacterium striatum, tunes the virulence of S. aureus and improves wound healing in murine and porcine models of S. aureus wound infection. Aim 3 is based on our observation that Alcaligenes faecalis wound isolates promote keratinocyte migration, cytokine secretion, and accelerated wound closure in a murine model of diabetic wound healing. We will establish the mechanism and therapeutic potential of A. faecalis-mediated host responses that lead to accelerated wound healing. The proposed research will use cutting-edge, cross-disciplinary approaches to investigate interactions between wound pathogens, wound “bystanders”, and the host; understanding these mechanisms will lead to improved DFU outcomes as our long-term objectives are to 1) develop novel microbiota-based interventions to improve healing that exploit microbial interactions with each other and the host; and 2) identify microbial biomarkers to classify patients at risk of complication.