BcpAIOB-Mediated CDI and Biofilm Formation in Burkholderia pseudomallei

BcpAIOB 介导的鼻疽伯克霍尔德氏菌中的 CDI 和生物膜形成

• 批准号: 8750147
• 负责人: Peggy A Cotter
• 金额: $ 22.23万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2016-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8750147
• 关键词: Acute; Aerosols; Alleles; Antibiotic Resistance; Antibiotics; Australia; Bacteria; Biological Assay; Burkholderia; Burkholderia pseudomallei; Cell Death; Cells; Centers for Disease Control and Prevention (U.S.); Communities; Cytoplasm; DNA; Decontaminant; Deletion Mutation; Development; Diagnostic tests; Disease; Dose; Ecology; Emerging Communicable Diseases; Engineering; Environment; Escherichia coli; Foundations; Genes; Genetic Polymorphism; Goals; Growth; Homologous Gene; Human; Immunity; Infection; Knowledge; Laboratory Study; Lung; Mediating; Melioidosis; Methods; Microbe; Microbial Biofilms; Modeling; Molecular; Organism; Pathogenesis; Physicians; Protein Binding; Proteins; Proteobacteria; Reporter; Role; Route; Soil; Southeastern Asia; Surface; System; Testing; Therapeutic; Tissues; Toxic effect; Toxin; Vaccines; Work; biothreat; killings; novel therapeutics; pathogenic bacteria; polypeptide; prevent; protein function; public health relevance; research study; transmission process

DESCRIPTION (provided by applicant): Burkholderia pseudomallei, a motile, Gram-negative, environmental saprotroph, is an emerging infectious disease problem and a previously-weaponinzed CDC Tier 1 select agent. It causes melioidosis in humans, which, in its acute form, can be fatal within days if untreated. Although endemic to southeast Asia and northern Australia, there is evidence that B. pseudomallei is spreading beyond established boundaries. Lack of a vaccine and lack of rapid diagnostic tests, together with the bacterium's low infectious dose and intrinsic antibiotic resistance, underscore the need to develop new therapeutics and new strategies for eliminating B. pseudomallei from contaminated environments, the only reservoir from which transmission to humans occurs. Contact-Dependent Growth Inhibition (CDI) is a phenomenon in which bacteria use the toxic C-terminus of a large surface-exposed exoprotein to inhibit the growth of neighboring bacteria upon cell-cell contact. If present in the cytoplasm, immunity proteins bind to the toxic polypeptides, blocking their catalytic activity and preventing cell death. The toxic C-termini of CDI system exoproteins and the immunity proteins are polymorphic and immunity proteins protect against CDI in an allele-specific manner. It has been suggested that this polymorphism allows bacteria to use CDI systems to discriminate self from non-self as a mechanism for kin selection in microbiological communities, but this hypothesis has not been tested. Whether there is a hierarchy of potencies of different CDI systems and whether the possession of multiple CDI systems is advantageous have also not been tested. We propose experiments to determine if bcpAIOB genes in B. pseudomallei do, as predicted, encode proteins that mediate interbacterial competition and biofilm formation in B. pseudomallei. We will determine if different bcpAIOB alleles encode proteins with different potencies, and if possession of multiple alleles confers a competitive advantage. We will also determine if inter-species CDI occurs and if Burkholderia thailandensis, a non-pathogen that lives in the same ecological niche as B. pseudomallei, can be engineered to produce multiple CDI systems and if this strain can out-compete B. pseudomallei and prevent or destroy B. pseudomallei biofilms. Our results will form the foundation for the exploitation of CDI systems for use as decontaminants and, potentially, therapeutics.

描述（由申请人提供）：类鼻疽伯克霍尔德氏菌是一种能运动的革兰氏阴性环境腐生菌，是一种新出现的传染病问题，也是一种先前武器化的 CDC 一级选择病原体。它会导致人类类鼻疽，如果不及时治疗，其急性形式可能在几天内致命。尽管是东南亚和澳大利亚北部的特有种，但有证据表明鼻疽伯克氏菌正在蔓延到既定边界之外。缺乏疫苗和快速诊断测试，再加上该细菌的低感染剂量和固有的抗生素耐药性，强调需要开发新的治疗方法和新策略，以从受污染的环境中消除拟鼻疽伯克氏菌，这是向人类传播的唯一储存库发生。 接触依赖性生长抑制 (CDI) 是细菌利用表面暴露的大外蛋白的有毒 C 末端来抑制细胞与细胞接触时邻近细菌生长的现象。如果存在于细胞质中，免疫蛋白会与有毒多肽结合，阻断其催化活性并防止细胞死亡。 CDI 系统外蛋白和免疫蛋白的有毒 C 末端是多态性的，免疫蛋白以等位基因特异性方式防御 CDI。有人提出，这种多态性允许细菌使用 CDI 系统来区分自我和非自我，作为微生物群落中亲缘选择的机制，但这一假设尚未得到检验。不同CDI系统是否存在效力等级以及拥有多个CDI系统是否有利也尚未得到测试。我们提出实验来确定类鼻疽伯克氏菌中的 bcpAIOB 基因是否如预测的那样编码介导类鼻疽伯克氏菌中细菌间竞争和生物膜形成的蛋白质。我们将确定不同的 bcpAIOB 等位基因是否编码具有不同效力的蛋白质，以及拥有多个等位基因是否会带来竞争优势。我们还将确定是否会发生种间 CDI，以及泰国伯克霍尔德氏菌（一种与类鼻疽伯克霍尔德氏菌生活在同一生态位的非病原体）是否可以被改造以产生多个 CDI 系统，以及该菌株是否可以在与类鼻疽伯克霍尔德氏菌的竞争中胜出。并防止或破坏类鼻疽伯克氏菌生物膜。我们的结果将为 CDI 系统的开发奠定基础 用作去污剂，并可能用作治疗剂。