Characterizing the Phenotype of Staphylococcal Biofilms

描述(由申请人提供)： 这项研究的主要目标是全面描述金黄色葡萄球菌生物膜的结构、生长和成熟，以及作为生物膜生长的葡萄球菌和浮游细胞在表型上的异同。特别是，我们将探索成熟生物膜和浮游细胞的黏附特性，因为它们对生物膜的启动和免疫系统的反应都是关键的。阐明这些表型差异可能最终导致设计新的葡萄球菌生物被膜预防和控制的治疗策略。我们假设表面表达的金黄色葡萄球菌蛋白的种类和数量因生长方式的不同而不同。我们进一步假设，在剪切条件下，这种差异将直接影响生物膜和分离的浮游细菌的黏附特性。该项目的具体目标是(1)研究在受控剪切条件下有血清和无血清条件下在蛋白质表面生长的葡萄球菌生物膜的结构，包括生长和发育特征；(2)表征在有血清和无血清条件下生长的葡萄球菌生物膜和分离的浮游细胞的粘附性，作为壁切应力的函数；(3)表征作为葡萄球菌生长方式的函数的细胞内、膜结合和分泌的蛋白质表达模式。将对不同生长阶段的悬浮培养、生物膜发育不同阶段的表面附着细胞以及生物膜脱落的浮游种群进行评估和比较。这些特定目标的完成将为设计新的治疗分子提供合理的基础。

DESCRIPTION (provided by applicant): The broad objective of this research is to comprehensively characterize the structure, growth and maturation of Staphylococcus aureus biofilms as well as the phenotypic similarities and differences between staphylococci grown as biofilm versus planktonic cells. In particular, we will probe the adhesion properties of both mature biofilms and planktonic cells since they are critical to both biofilm initiation and immune system response. Elucidation of these phenotypic differences may ultimately lead to the design of novel therapeutic strategies for staphylococcal biofilm prevention and control. We hypothesize that the repertoire and number of surface expressed S. aureus proteins vary depending on the mode of growth. We further hypothesize that this variance will directly affect the adhesion properties of both the biofilm and detached planktonic bacteria under shear conditions. The specific aims of the project are to (1) investigate the architecture of staphylococcal biofilms grown on protein surfaces in the presence and absence of serum under controlled shear conditions, including growth and developmental characteristics, (2) characterize adhesion properties of staphylococcal biofilms and detached planktonic cells grown in the presence and absence of serum as a function of wall shear stress and (3) characterize the intracellular, membrane-bound and secreted protein expression patterns as a function of how staphylococci are grown. Suspension cultures at various growth stages, surface-attached cells in various stages of biofilm development, and planktonic populations shed from biofilms will be evaluated and compared. Completion of these specific aims will provide a rational basis for the design of new therapeutic molecules.