Genomics/Proteomics of Enterotoxin B Producing S. aureus

描述（由申请人提供）：金黄色葡萄球菌产生许多肠毒素（SEs），这些肠毒素是葡萄球菌性食物中毒的病原体。SEs的基因位于质粒、噬菌体和其他潜在的可移动遗传元件（如致病性岛）上，进一步增加了它们向环境中其他生物体传播的可能性。葡萄球菌肠毒素B （SEB）是NIAID B类优先制剂，通常由产毒素金黄色葡萄球菌菌株产生的水平远高于其他SEs。此外，不同金黄色葡萄球菌菌株产生的SEB水平是高度可变的。最近的研究表明，SEB可能调节包括毒力因子在内的其他细胞外蛋白的合成，从而影响葡萄球菌的毒力。本探索性/发展性提案的目标是研究各种产生SEB的金黄色葡萄球菌菌株的基因表达和蛋白质组学特征，并进一步验证金黄色葡萄球菌菌株表达SEB可能影响细胞内和细胞外蛋白（包括其他毒素和毒力因子）产生的假设。这将通过NIAID通过TIGR/PFGRC提供给我们的金黄色葡萄球菌微阵列对不同的seb产生菌株进行比较基因组分析来完成。我们还将使用微阵列技术研究这些菌株的细胞基因表达谱。SEB对等基因金黄色葡萄球菌菌株整体基因表达的影响也将利用微阵列技术进行研究。我们还将利用荧光染料对产生seb的金黄色葡萄球菌菌株以及seb阳性/ seb阴性菌株对等基因的蛋白质组进行研究。这些菌株中蛋白质含量和特定蛋白质水平的差异将通过质谱法确定。这些研究的成功完成将为进一步分析SEB产生调控的分子机制及其对葡萄球菌基因表达和发病机制的影响提供坚实的基础。

DESCRIPTION (provided by applicant): Staphylococcus aureus produces a number of enterotoxins (SEs) which are the causative agents of staphylococcal food poisoning. The genes for SEs are located on plasmids, phages and other potentially movable genetic elements such as pathogenicity islands, further increasing their possible spread to other organisms in the environment. Staphylococcal enterotoxin B (SEB) is an NIAID Category B Priority agent and is generally produced at much higher levels than other SEs by toxigenic S. aureus strains. Furthermore, the levels of SEB produced by different S. aureus strains are highly variable. Recent studies suggest that SEB may regulate the synthesis of other extracellular proteins including virulence factors, thereby affecting staphylococcal virulence. The goal of this Exploratory/Developmental proposal is to study the gene expression and proteomic profiles of various SEB-producing S. aureus strains and to further test the hypothesis that expression of SEB by S. aureus strains may affect the production of intracellular and extracellular proteins, including other toxins and virulence factors. This will be accomplished by a comparative genomic analysis of different SEB-producing strains utilizing S. aureus microarrays provided to us by NIAID through TIGR/PFGRC. We will also study the cellular gene expression profiles in these strains using microarrays. The effect of SEB on global gene expression in isogenic S. aureus strains will also be studied utilizing the microarray technology. We will also study the proteomes of SEB-producing S. aureus strains as well as pairs of isogenic SEB-positive/SEB-negative strains by two-dimensional Difference Gel Electrophoresis using fluorescence dyes. Differences in the protein content and levels of particular proteins in these strains will be identified by mass spectrometry. Successful completion of these studies will provide a solid basis for future analysis of the molecular mechanisms involved in the regulation of SEB production, and its effect on staphylococcal gene expression and pathogenesis.