Candida albicans gene expression during intra-abdominal infections

腹腔内感染期间白色念珠菌基因表达

• 批准号: 8642813
• 负责人: M. Hong Thi NGUYEN
• 金额: $ 25.39万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-01 至 2016-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8642813
• 关键词: Abdominal Abscess; Abdominal Infection; Abscess; Accounting; Biological Assay; Blood Vessels; Candida; Candida albicans; Candidiasis; Catheters; Collection; Communicable Diseases; Complementary DNA; Complication; Data; Development; Diagnostic; Disease; Disseminated candidiasis; Escherichia coli; Extravasation; Feces; Functional disorder; Future; Gastrointestinal tract structure; Gene Deletion; Gene Expression; Gene Expression Profile; Genes; Goals; Greater sac of peritoneum; Hospitals; Human; Infection; Intra-abdominal; Lead; Literature; Measures; Modeling; Molecular; Molecular Profiling; Mucous Membrane; Mus; Mycoses; Operative Surgical Procedures; Pancreatitis; Paper; Pathogenesis; Pathway interactions; Patient Care; Patients; Perforation; Peritoneal; Peritoneal Dialysis; Peritoneal Fluid; Peritoneum; Peritonitis; Process; Publishing; Pus; RNA; Relative (related person); Research Personnel; Sampling; Sepsis; Site; Staging; Sterility; Surgeon; Testing; Tissues; Transcript; Vaccines; Virulence; candidemia; deep sequencing; gastrointestinal; gastrointestinal bacteria; gastrointestinal perforation; gene complementation; genome-wide; human disease; in vivo; insight; mortality; mouse model; mutant; nano-string; neutrophil; novel therapeutics; oropharyngeal thrush; pathogen; public health relevance; response; transcriptome sequencing

PROJECT SUMMARY Invasive candidiasis (IC), the most common fungal infection in U.S. hospitals, is associated with mortality rates as high as 40%. Bloodstream infections (candidemia) are generally accepted as the most important type of IC. Intra-abdominal candidiasis (IAC) and other non-bloodstream IC are less well-studied. IAC encompasses two entities: peritonitis (infection of the peritoneum) and abscesses (collections of Candida and pus that are walled-off from healthy tissue). Data from recent papers and our center indicate that IAC is at least as common as candidemia, and mortality rates are similar. Nevertheless, the diseases differ in important ways. The most common portals of entry for candidemia are translocation from the gastrointestinal (GI) lumen through the mucosa into the vasculature or direct introduction from vascular catheters. IAC, on the other hand, follows the introduction of Candida into the normally sterile peritoneal cavity as a complication of peritoneal dialysis or, more commonly, as a result of GI tract leakage or perforation. In the latter scenarios, Candida is admixed with fecal material and, in most cases, GI bacteria such as E. coli. Candida albicans remains the most common cause of IAC, whereas non-C. albicans species are now predominant in candidemia. The cellular and molecular mechanisms by which C. albicans causes IAC are poorly understood. We have adapted a simple and reproducible mouse model of C. albicans IAC that replicates the pathophysiology and progression of infection from generalized peritonitis to localized intra-abdominal abscesses. We used nanoString nCounter assays to measure expression of 145 C. albicans genes during peritonitis. Moreover, we demonstrated that the mouse model is sensitive at distinguishing the relative virulence of mutant C. albicans strains, indicating that it is well-suited to studies of pathogenesis. These data provided valuable insights into biologic processes that are activated by C. albicans in vivo, and revealed that C. albicans gene expression during IAC differs substantially from DC or OPC. More recently, we have performed RNA-Seq (deep sequencing of cDNA) to comprehensively define C. albicans gene expression within peritoneal fluid recovered from a patient with peritonitis. In this project, we will test two hypotheses: 1) C. albicans elaborates stage-specific gene expression profiles within the peritoneal cavity and abscesses; and 2) C. albicans genes that are temporal-spatially regulated during IAC make distinct contributions to pathogenesis. In our first specific aim, we will use RNA-Seq to measure C. albicans gene expression during IAC in mice and humans. In our second specific aim, we will use our mouse model to implicate specific C. albicans genes in the pathogenesis of IAC. In addition to providing insights into genes and biologic processes that contribute to IAC, the project will lead to future studies of specific mechanisms of pathogenesis. This study will generate new hypotheses about pathogenesis, and help inform choices of genes and pathways that can be pursued by investigators in the field. In addition, the data may identify priority targets for the development of novel therapeutic, diagnostic and vaccine strategies.

项目摘要 侵袭性念珠菌病（IC）是美国医院最常见的真菌感染，与死亡率相关 高达40%。血液感染（念珠菌血症）通常被认为是最重要的类型， IC.腹腔内念珠菌病（IAC）和其他非血流IC的研究较少。IAC包括 两个实体：腹膜炎（腹膜感染）和脓肿（念珠菌和脓的集合， 与健康组织隔离）。最近的论文和我们中心的数据表明，IAC至少是常见的 和死亡率相似。然而，这些疾病在重要方面有所不同。最 念珠菌血症的常见入口是从胃肠道（GI）腔通过 粘膜进入脉管系统或从血管导管直接引入。另一方面，IAC遵循 腹膜透析并发症将念珠菌引入正常无菌的腹膜腔，或， 更常见的是，由于胃肠道泄漏或穿孔。在后一种情况下，念珠菌与 粪便物质和大多数情况下的胃肠道细菌如大肠杆菌。杆菌白色念珠菌仍然是最常见的 而非C.现在白色念珠菌属在念珠菌血症中占优势。细胞和 C.白色念珠菌引起IAC的原因知之甚少。我们采用了一种简单的 和可重复的C.白色念珠菌IAC，复制的病理生理学和进展， 从全身性腹膜炎到局限性腹腔内脓肿的感染。我们使用nanoString nCounter 测定145 C.白念珠菌基因在腹膜炎。此外，我们证明， 小鼠模型在区分突变体C的相对毒力方面是敏感的。白色念珠菌菌株，表明它 非常适合研究发病机制。这些数据提供了宝贵的见解，生物过程， 激活C。albicans的体外培养结果表明，C.白念珠菌基因在IAC中的表达与 DC或OPC。最近，我们进行了RNA-Seq（cDNA深度测序）， 定义C.从腹膜炎患者回收的腹膜液中的白色念珠菌基因表达。在这 项目，我们将测试两个假设：1）C。白念珠菌阐述了阶段特异性基因表达谱， C.腹腔及腹腔积液;白念珠菌基因在IAC过程中的时空调控 对发病机制有着独特的贡献。在我们的第一个具体目标中，我们将使用RNA-Seq来测量C。 白念珠菌基因表达在小鼠和人类IAC期间。在我们的第二个特定目标中，我们将使用鼠标 模型来暗示特定的C.白念珠菌基因在IAC发病机制中的作用。除了提供有关以下方面的见解之外， 基因和生物过程，有助于IAC，该项目将导致未来的研究，具体 发病机制。这项研究将产生关于发病机制的新假设， 基因和途径的选择，可以在该领域的研究人员追求。此外，数据可能 确定开发新的治疗、诊断和疫苗战略的优先目标。