Characterization of a novel S. aureus biofilm polysaccharide

新型金黄色葡萄球菌生物膜多糖的表征

• 批准号: 10193081
• 负责人: Chia Y. Lee
• 金额: $ 19万
• 依托单位: UNIV OF ARKANSAS FOR MED SCIS
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-03-16 至 2023-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10193081
• 关键词: Antibiotic Resistance; Antibiotic Therapy; Antibodies; Applications Grants; Bacteria; Bacterial Antibiotic Resistance; Biochemical; Carbohydrates; Cause of Death; Cells; Chemical Structure; Chromatography; Chromosomes; Communities; Confocal Microscopy; DNA; Development; Diagnostic; Disease; Extracellular Matrix; Failure; Foundations; Gel; Gene Cluster; Genes; Genome; Genus staphylococcus; Goals; HIV; Hospitals; Immune; Immune system; Implant; In Vitro; Infection; Knowledge; Mass Spectrum Analysis; Methods; Microbial Biofilms; Modeling; Molecular; Mus; Mutation; NMR Spectroscopy; Names; Operon; Organism; Osteomyelitis; Pattern; Polyacrylamide Gel Electrophoresis; Polysaccharides; Production; Proteins; Reporting; Role; Solid; Staphylococcal Infections; Staphylococcus aureus; Structure; Surface; System; Tissues; Variant; Virulence; Virulence Factors; Virulent; bacterial community; bacterial resistance; chronic infection; emerging antibiotic resistance; experimental study; extracellular; gene synthesis; genetic approach; genetic resistance; genomic locus; human disease; human pathogen; implantable device; in vivo; mutant; new therapeutic target; novel; novel diagnostics; pathogen; pathogenic bacteria; protein complex; resistance gene; resistant strain; targeted treatment; trait

Summary Staphylocuccus aureus is a significant human pathogen that causes a wide range of diseases, some of which are serious and difficult to treat. Current treatment methods are largely limited to antibiotic therapy. However, S. aureus is capable of forming biofilm on implants or tissues rendering the bacteria resistance to antibiotics and to host immune defense system without acqiuring genetic resistance traits. Thus, biofilm formation often leads to treament failures. Biofilms are bacterial communities consist of multiple layers of bacterial cells encased within an extracellular matrix that keeps the bacteria within the biofilm structure. To date, staphylococcal biofilm matrix has been shown to consist of polysaccharides, proteins and extracellular DNA but the composition is not been fully defined. Understanding biofilm matrix composition is therefore critical to unveil biofilm formaiton mechanism and provide potential targets for therapeutic or diagnostic development. Diverse biofilm matrix proteins have been reported but only very few species of matrix polysaccharide have been identified. We have shown that mutations in an previously uncharacterized gene cluster of putative polysaccharide sythesis genes in the S. aureus genome reduced biofilm formation. These results indicate that the gene cluster is involved in the production of a novel polysaccharide, which contributes to S. aureus virulence by promoting biofilm formation. Thus, the goal of this application is to verify and study this novel polysaccharide. To this end, we will molecularly characterize the gene cluster and biochemically identify the novel polysaccharide in Aim 1 and study the role of this polysacharide in biofilm formation and in virulence in an implant bone infection model in Aim 2.

概括 金黄色葡萄球菌是一种重要的人类病原体，可引起多种疾病，其中一些疾病 病情严重且难以治疗。目前的治疗方法主要限于抗生素治疗。然而，S. 金黄色葡萄球菌能够在植入物或组织上形成生物膜，使细菌对抗生素产生耐药性 宿主免疫防御系统而不获得遗传抗性特征。因此，生物膜的形成常常导致 治疗失败。生物膜是细菌群落，由包裹在其中的多层细菌细胞组成 将细菌保持在生物膜结构内的细胞外基质。迄今为止，葡萄球菌生物膜基质 已被证明由多糖、蛋白质和细胞外DNA组成，但其成分尚未确定 完全定义。因此，了解生物膜基质组成对于揭示生物膜形成机制至关重要 并为治疗或诊断开发提供潜在目标。多种生物膜基质蛋白具有 已有报道，但仅鉴定了极少数种类的基质多糖。我们已经证明 S. 中先前未表征的假定多糖合成基因的基因簇中的突变。 金黄色葡萄球菌基因组减少了生物膜的形成。这些结果表明该基因簇参与了 产生一种新型多糖，该多糖通过促进生物膜形成来增强金黄色葡萄球菌的毒力。 因此，本申请的目的是验证和研究这种新型多糖。为此，我们将从分子 表征基因簇并通过生化方法鉴定目标 1 中的新型多糖，并研究其作用 这种多糖在目标 2 的植入骨感染模型中的生物膜形成和毒力中的作用。