Genomics/Proteomics of Enterotoxin B Producing S. aureus

性状（由申请方提供）：金黄色葡萄球菌产生多种肠毒素（SE），是葡萄球菌食物中毒的病原体。SEs的基因位于质粒、质粒和其他潜在的可移动遗传元件（如致病岛）上，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（SE B）是NIAID B类优先病原体，通常由致炎性链球菌产生的水平远高于其他SE。金黄色葡萄球菌此外，不同S.金黄色葡萄球菌菌株变异性很大。最近的研究表明，SEB可能调节其他细胞外蛋白的合成，包括毒力因子，从而影响葡萄球菌的毒力。本探索性/开发性提案的目标是研究各种SEB产生菌的基因表达和蛋白质组特征。金黄色葡萄球菌菌株中表达SEB，并进一步验证了S.金黄色葡萄球菌菌株可能影响细胞内和细胞外蛋白质的产生，包括其他毒素和毒力因子。这将通过利用S.由NIAID通过TIGR/PFGRC提供给我们的金黄色葡萄球菌微阵列。我们还将使用微阵列研究这些菌株的细胞基因表达谱。SEB对同基因S.还将利用微阵列技术研究金黄色葡萄球菌菌株。我们还将研究SEB产生菌S.金黄色葡萄球菌菌株以及成对的同基因SEB阳性/SEB阴性菌株。将通过质谱法鉴定这些菌株中蛋白质含量和特定蛋白质水平的差异。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.