Staphylococcus aureus biofilms: in vitro and in vivo studies

描述(申请人提供)：金黄色葡萄球菌是一种革兰氏阳性细菌，普遍存在，自然界中的主要宿主是人类。植入式医疗设备，如髓内棒、螺丝钉、钢板和人工关节的使用增加，为微生物引起感染提供了一个生理生态位。虽然许多细菌种类可能会导致留置医疗器械的微生物污染，但金黄色葡萄球菌导致了这些感染的大部分，产生了很高的慢性化、发病率和死亡率。金黄色葡萄球菌能够在留置医疗器械上持续感染的一个重要机制是通过定植和合成一层“粘液层”，称为糖萼或生物膜。这一层防止了抗菌剂和宿主吞噬细胞对感染的分解。一旦植入物被定植，慢性感染接踵而至，标准的治疗选择是植入物移除。这项建议试图用双向凝胶电泳法鉴定生物膜中金黄色葡萄球菌基因产物的表达上调。然后，将评估选定的上调蛋白，首先是它们在体内生物膜感染期间被宿主免疫系统识别的能力，其次是它们在防止兔植入相关感染模型中的感染方面的保护效果。这里产生的数据可能有助于最终开发针对人类感染金黄色葡萄球菌生物膜的疫苗。此外，这项建议还将有助于更全面地了解金黄色葡萄球菌生物膜形成和成熟所涉及的细菌因素。这一理解将使人们能够创造新的材料、表面和/或消毒策略，以抵抗或消除葡萄球菌污染和生物膜的形成。此外，蛋白质组将与PI实验室已经完成的转录组DMA微阵列研究进行比较，以确定在流动条件下生长的金黄色葡萄球菌生物膜的基因表达和蛋白质生产之间的全球相互关系，从而使人们在一个新的水平上了解葡萄球菌。最后，金黄色葡萄球菌生物被膜形成的评价结果可作为其他革兰氏阳性菌如链球菌、李斯特菌、梭状芽孢杆菌生物被膜形成的模型。和芽孢杆菌(Bacillusspp.)

DESCRIPTION (provided by applicant): Staphylococcus aureus is a gram positive, ubiquitous bacterial species, with the predominant reservoir in nature being humans. The increased use of implanted medical devices such as intramedullary rods, screws, plates, and artificial joints has provided a physiological niche for microbes to cause infections. While a number of bacterial species may cause microbial fouling of indwelling medical devices, S. aureus causes a majority of these infections, producing high chronicity, morbidity, and mortality. One of the important mechanisms by which S. aureus is able to cause persistent infections on indwelling medical devices is through colonizing and synthesizing a "slime" layer, termed the glycocalyx or biofilm. This layer prevents infection resolution by antimicrobial agents and host phagocytic cells. Once an implant is colonized and chronic infection ensues, the standard treatment option is implant removal. This proposal seeks to identify S. aureus gene products with upregulated production in biofilms using two dimensional (2D) gel electrophoresis. Selected up-regulated proteins will then be evaluated, first, for their ability to be recognized by the host immune system during an in vivo biofilm infection, and second, for their protective efficacy in preventing infections in an implant-associated infection model in rabbits. The data generated here may contribute to the eventual development of a vaccine against S. aureus biofilms infections in humans. In addition, this proposal will also contribute to a more complete understanding of the bacterial factors involved in S. aureus biofilm formation and maturation. This understanding will enable one to create novel materials, surfaces, and/or disinfection strategies that resist or eliminate staphylococcal fouling and biofilm formation. Also, the proteome will be compared to transcriptome DMA microarray studies already completed in the Pi's laboratory in order to determine the global interrelation between gene expression and protein production for S. aureus biofilms grown under flow, thereby allowing staphylococci to be understood at a new level. Lastly, the results obtained in the evaluation of S. aureus biofilm formation may be used as a model for the biofilm formation by other closely related gram positive bacterial species, including Streptococcus spp., Listeria spp., Clostridium spp. and Bacillus spp.