Revisiting alginate paradigms

项目摘要 本申请旨在通过以下方式定义藻酸盐过量生产的分子机制和适合性益处 铜绿假单胞菌的粘液变异体。具体来说，我们将定义藻酸盐生物膜基质的特征 这增强了铜绿假单胞菌的持久性，并更好地理解了藻酸盐在维持被动状态中的作用 CF呼吸道铜绿假单胞菌微生物群落的保护。 这项提议将使用最先进的分子、生化、免疫学和遗传学方法来探测 海藻酸盐致病机制的一些方面，并重新评估一些长期存在的范例。到目前为止，这些机制 产生藻酸盐的细菌形成生物膜的基础还不是很清楚。目标1将调查 藻酸盐生物膜基质维持生物膜完整性、结构和功能的生化和遗传学基础 抗菌剂抗性特性。虽然很明显，粘液变异体在慢性呼吸道中占主导地位 在CF患者中，感染很少以纯克隆性粘液分离株的形式出现。相反，粘液细菌是 典型地与未发生粘液的野生型铜绿假单胞菌混合种群有关 转化，以及自发产生的抑制者。目标2的目标是测试这一假设 混合联合体赋予铜绿假单胞菌群落作为一个整体的健康益处，这在 非粘液性细菌或单独粘液性细菌。藻酸盐在CF肺中的表达与临床不良相关 预后。然而，关于藻类形成的特定性质，我们的知识存在空白 过度生产导致呼吸道内的细菌和微生物联合体。这些目标的实现 将导致对藻酸盐生物学的更深入了解，并转化为治疗CF的新疗法或干预措施 感染粘液型铜绿假单胞菌的患者。

Project Abstract This application seeks to define the molecular mechanisms and fitness benefits of alginate overproduction by mucoid variants of Pseudomonas aeruginosa. Specifically we will define features of the alginate biofilm matrix that enhance P. aeruginosa persistence and better understand the role of alginate in maintaining passive protection to the P. aeruginosa microbial community in the CF airway. This proposal will use state-of-the art molecular, biochemical, immunological, and genetic approaches to probe aspects of alginate pathogenesis and to reevaluate some long-standing paradigms. To date, the mechanisms underlying biofilm formation by alginate producing bacteria is not well understood. Aim 1 will investigate the biochemical and genetic basis for alginate biofilm matrix maintenance of biofilm integrity, structure, and antimicrobial resistance properties. While it is clear that mucoid variants predominate during chronic airway infection in CF patients, rarely are they present as pure clonal mucoid isolates. Instead, mucoid bacteria are typically associated with mixed populations of wild type P. aeruginosa that have not undergone mucoid conversion, as well as spontaneous suppressors that arise. The goal of Aim 2 is to test the hypothesis that this mixed consortia confers fitness benefits to the P. aeruginosa community as a whole that is not observed in either nonmucoid or mucoid bacteria alone. Alginate expression in the CF lung correlates with a poor clinical prognosis. However there are gaps in our knowledge regarding specific properties that alginate overproduction affords bacteria and the microbial consortia within the airway. The completion of these aims will lead to a deeper understanding of alginate biology and translate into novel therapies or interventions for CF patients colonized with mucoid P. aeruginosa.