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（由申请方提供）：类鼻疽伯克霍尔德菌是一种能动的革兰氏阴性环境腐生性微生物，是一种新出现的传染病问题，也是CDC先前武器化的1级选择因子。它会导致人类类鼻疽病，如果不治疗，急性形式的类鼻疽病可能在几天内致命。虽然是东南亚和澳大利亚北方的特有种，但有证据表明B。假鼻疽正在蔓延缺乏疫苗和快速诊断测试，加上细菌的低感染剂量和内在的抗生素耐药性，强调了开发新疗法和消除B的新策略的必要性。从受污染的环境中传播的类鼻疽，是发生向人类传播的唯一宿主。 接触依赖性生长抑制（CDI）是细菌在细胞-细胞接触时使用大的表面暴露的外蛋白的毒性C-末端来抑制邻近细菌生长的现象。如果存在于细胞质中，免疫蛋白质与毒性多肽结合，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毒性C-末端是多态性的，并且免疫蛋白以等位基因特异性方式保护免受CDI。有人认为，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属选择的机制，但这一假设尚未得到验证。不同CDI系统的效力是否存在层级，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是否bcpA 10 B基因在B。正如所预测的，类鼻疽杆菌确实编码介导B中细菌间竞争和生物膜形成的蛋白质。假鼻疽我们将确定不同的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赋予竞争优势。我们还将确定是否发生种间CDI，以及是否存在与B生活在相同生态位的非病原体--泰国伯克霍尔德氏菌。类鼻疽杆菌，可以被工程化以产生多种CDI系统，并且如果该菌株可以胜过B。预防或消灭B。类鼻疽菌生物膜我们的研究结果将为CDI系统的开发奠定基础， 用作去污剂和潜在的治疗剂。