The pel exopolysaccharide gene cluster of Pseudomonas aeruginosa

描述（由申请人提供）：铜绿假单胞菌发病机制的一个重要特征是能够形成称为生物膜的表面相关群落。几种类型的铜绿假单胞菌感染的特征在于生物膜形成，包括留置医疗装置的定殖和患有囊性纤维化（CF）的人的气道中存在的慢性感染。生物膜细菌产生一种或多种细胞外聚合物（EPS），其充当支架，将生物膜细胞保持在一起并保持到表面。一段时间以来，藻酸盐被认为是铜绿假单胞菌EPS生物膜基质的主要多糖。最近，我们的研究表明，藻酸盐是不是一个重要组成部分的非粘液样菌株，这是负责大多数机会性生物膜感染，也是第一个定殖CF患者的EPS基质。相反，似乎有其他EPS组分介导生物膜形成。我们的实验室和其他人发现，铜绿假单胞菌有能力编码两种替代多糖，命名为Psl和Pel，它们在细胞表面相互作用和生物膜形成中起关键作用。该提案的重点是Pel基因簇。我们的总体目标是确定Pel在生物膜发育、结构、抗菌药物耐药性和发病机制中的作用。对这一关键生物膜组分的进一步了解将导致旨在抑制生物膜形成的策略，这是铜绿假单胞菌发病机制的一个关键方面。尽管我们对铜绿假单胞菌生物膜形成的认识有了显著的进步，但我们对生物膜基质组成以及负责产生这种基质的基因的理解仍然存在差距。我们发现了一个新的EPS位点，这是形成铜绿假单胞菌生物膜所必需的。由于基质提供了关键的保护作用以及用于形成生物膜的支架，因此旨在破坏基质的试剂将具有治疗价值。对Pel的彻底分析可能会导致此类药物的开发，并改善C患者以及涉及生物膜的其他铜绿假单胞菌感染个体的生活质量。公共卫生相关性：本研究旨在探讨铜绿假单胞菌生物被膜胞外多糖Pel在铜绿假单胞菌生物被膜形成和致病中的作用。Pel在多糖产生、生物膜形成和发病机制中的作用将被探索。

DESCRIPTION (provided by applicant): An important feature of Pseudomonas aeruginosa pathogenesis is the ability to form surface- associated communities called biofilms. Several types of P. aeruginosa infections are characterized by biofilm formation, including the colonization of indwelling medical devices and the chronic infections present in the airways of people suffering from cystic fibrosis (CF). Biofilm bacteria produce one or more extracellular polymeric substances (EPS) that act as a scaffold, holding biofilm cells together and to a surface. For some time, alginate has been considered the major polysaccharide of the P. aeruginosa EPS biofilm matrix. Recently, our studies indicate that alginate is not a significant component of the EPS matrix of nonmucoid strains, which are responsible for most opportunistic biofilm infections and are also the first to colonize CF patients. Instead, there appear to be other EPS components that mediate biofilm formation. Our lab and others discovered that P. aeruginosa has the capacity to encode two alternative polysaccharides, designated Psl and Pel, which play critical roles in cell surface interactions and biofilm formation. The focus of this proposal is the Pel gene cluster. Our overall objective is to determine the role of Pel in biofilm development, structure, resistance to antimicrobial agents, and pathogenesis. A further understanding of this critical biofilm component will lead to strategies aimed at inhibiting biofilm formation, a key aspect of P. aeruginosa pathogenesis. Despite significant advancements in our knowledge of P. aeruginosa biofilm development, there remain gaps in our understanding of the biofilm matrix composition, as well as the genes responsible for producing this matrix. We have discovered a novel EPS locus that is essential for formation of P. aeruginosa biofilms. Since the matrix provides a critical protective role as well as a scaffold for the developing biofilm, agents aimed at disrupting the matrix would have therapeutic value. A thorough analysis of Pel may lead to the development of such agents and improve the quality of life for C patients as well as individuals with other P. aeruginosa infections that involve biofilms. PUBLIC HEALTH RELEVANCE: is proposal is focused on examining the role of the important biofilm exopolysaccharide Pel in Pseudomonas aeruginosa biofilm formation and pathogenesis. The role of Pel in polysaccharide production, biofilm formation and pathogenesis will be explored.