Streptococcal virulence factors in extra-oral disease

产品说明：感染性心内膜炎是一种严重的疾病，需要长期的医疗或手术治疗，导致严重的并发症，包括充血性心力衰竭和中风，并且即使治疗也往往是致命的。草绿色链球菌作为一个群体，特别是血链球菌是这种疾病的主要原因。鉴定链球菌毒力决定因子将有助于更好地了解链球菌心内膜炎的发病机制，并确定预防和治疗的靶点。我们已经应用签名标记诱变（STM），以确定血链球菌心内膜炎的毒力因子。这种方法依赖于动物模型中的感染过程，以确定致病所需的细菌基因。我们最初的三年计划导致了一种体外转座STM技术的适应，用于S。sanguis和800个标记突变体的创建和筛选。本申请提出使用STM和非STM方法来检查细胞壁锚定蛋白和脂蛋白对心内膜炎毒力的贡献。色葡萄用于这些分析的sanguis菌株也正在由我们和我们的合作者进行测序，并即将完成。序列的可用性将允许使用靶向方法进行剩余的诱变，所述靶向方法涉及体外转座到确定的扩增子中。这种方法在技术上比我们以前的STM分析更简单，也将提供更多的信息，允许将这些基因分类为培养物中正常生长所必需的，心内膜炎毒力所必需的，或两种性状所必需的。这种方法将提供一个全面的分析两类表面蛋白在心内膜炎毒力的作用。我们也希望这项研究能检测几乎所有的潜在疫苗候选人在沙门氏菌。并找出那些最有希望的人。

DESCRIPTION: Infective endocarditis is a serious illness that requires lengthy medical or surgical treatment, causes severe complications including congestive heart failure and stroke, and is often fatal, even when treated. The viridans streptococci as a group and Streptococcus sanguis in particular are a leading cause of this disease. Identification of streptococcal virulence determinants would lead to a better understanding of the pathogenesis of streptococcal endocarditis and to the identification of targets for prevention and therapy. We have applied signature-tagged mutagenesis (STM) to identify Streptococcus sanguis virulence factors for endocarditis. This approach relies on the infection process in an animal model to identify bacterial genes needed for disease causation. Our initial three-year project resulted in adaptation of an in vitro transposition STM technique for use with S. sanguis and the creation and screening of 800 tagged mutants. The current application proposes to use STM and non-STM approaches to examine the contribution of cell wall-anchored proteins and lipoproteins to endocarditis virulence. The S. sanguis strain being used for these analyses is also being sequenced by us and our collaborators and is near completion. The availability of the sequence will allow for the remainder of the mutagenesis to be performed using a targeted approach involving in vitro transposition into defined amplicons. This approach will be technically simpler than our previous STM analysis and will also be more informative, allowing for categorization of these genes as essential for normal growth in culture, essential for endocarditis virulence, or dispensable for both traits. This approach will provide a comprehensive analysis of the role of two classes of surface proteins in endocarditis virulence. We also expect the study to examine virtually all potential vaccine candidates in S. sanguis and to identify those that are most promising.