Genomics/Proteomics of Enterotoxin B Producing S. aureus

说明(申请人提供)：金黄色葡萄球菌产生多种肠毒素，是葡萄球菌食物中毒的病原体。SES的基因位于质粒、噬菌体和其他潜在可移动的遗传元件上，如致病岛，进一步增加了它们向环境中其他生物传播的可能性。葡萄球菌肠毒素B(SEB)是一种NIAID B类优先药物，由产毒金黄色葡萄球菌产生的肠毒素B通常比其他SE的水平高得多。此外，不同金黄色葡萄球菌菌株产生的SEB水平差异很大。最近的研究表明，SEB可能调节包括毒力因子在内的其他胞外蛋白的合成，从而影响葡萄球菌的毒力。这一探索性/发展性建议的目的是研究各种产生SEB的金黄色葡萄球菌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表达SEB可能影响细胞内和细胞外蛋白质的产生的假设，包括其他毒素和毒力因子。这将通过使用NIAID通过TIGR/PFGRC向我们提供的金黄色葡萄球菌微阵列对不同的SEB产生菌进行比较基因组分析来完成。我们还将利用微阵列研究这些菌株的细胞基因表达谱。此外，还将利用微阵列技术研究SEB对金黄色葡萄球菌等基因菌株全球基因表达的影响。我们还将利用荧光染料的双向差示凝胶电泳法研究产生SEB的金黄色葡萄球菌以及同基因的SEB阳性/SEB阴性菌株的蛋白质组。这些菌株的蛋白质含量和特定蛋白质水平的差异将通过质谱仪进行鉴定。这些研究的成功完成将为未来分析SEB产生调控的分子机制及其对葡萄球菌基因表达和致病机制的影响奠定坚实的基础。

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.