Characterizing the Phenotype of Staphylococcal Biofilms

描述（由申请人提供）： 本研究的主要目的是全面表征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与作为增殖细胞生长的葡萄球菌之间的表型相似性和差异。特别是，我们将探测成熟生物膜和粘附细胞的粘附特性，因为它们对生物膜的启动和免疫系统反应都至关重要。阐明这些表型差异可能最终导致设计新的治疗策略，用于葡萄球菌生物膜预防和控制。我们推测，表面表达的S。金黄色葡萄球菌蛋白根据生长模式而变化。我们进一步假设，这种变化将直接影响剪切条件下的生物膜和分离的粘附细菌的粘附特性。该项目的具体目标是（1）研究在受控剪切条件下，在存在和不存在血清的情况下，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）表征在存在和不存在血清的情况下生长的葡萄球菌生物膜和分离的粘附细胞的粘附特性作为壁剪切应力的函数，以及（3）表征葡萄球菌如何生长的功能的细胞内、膜结合和分泌蛋白表达模式。将评价和比较不同生长阶段的悬浮培养物、不同生物膜发育阶段的表面附着细胞以及从生物膜脱落的嗜酸性群体。这些特定目标的实现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.