Analysis of Fur Regulated Genes in Staphylococcus aureus

金黄色葡萄球菌毛皮调控基因分析

• 批准号: 7012363
• 负责人: RADHESHYAM K JAYASWAL
• 金额: $ 21.45万
• 依托单位: ILLINOIS STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7012363
• 关键词: DNA footprinting; Staphylococcus aureus; Staphylococcus infection; bacterial cytopathogenic effect; bacterial genetics; bacterial proteins; binding sites; disease /disorder model; gel mobility shift assay; gene expression; genetic regulation; host organism interaction; iron; kidney disorder; laboratory mouse; microarray technology; microorganism culture; northern blottings; nucleic acid sequence; phenotype; regulatory gene; site directed mutagenesis; virulence

DESCRIPTION (provided by applicant): Staphylococcus aureus is a major cause of human diseases. The acquisition of broad antibiotic resistance in this bacterium, especially, methicillin and vancomycin-resistant S. aureus strains pose a major threat to public health. Various stress conditions within the host are proposed to stimulate the expression of virulence genes in S. aureus. Iron, which has been shown to be an important virulence determinant and required for many vital cellular processes, is not readily available for bacterial cells in the animal host. To cope with an iron-deficient host environment, the bacteria have evolved several mechanisms for iron acquisition regulation. We have cloned and characterized a ferric-uptake regulatory gene (fur) from S. aureus. This gene codes for a protein, Fur, which in the presence of sufficient intracellular iron binds to a specific DNA sequence located in the promoters of sirA and fhu and regulated their expression (Xiong et al., 2000; Cabrera et al., 2001). Our recent DNA microarray analyses indicated that many genes are differentially expressed by iron. Whether these genes are directly or indirectly under the control of Fur-iron cannot be distinguished by the microarray analysis. Therefore I propose to identify some of those genes, which are directly under the control of Fur regulation and involved in the pathogenesis of S. aureus. The long-term objective of this study is to identify Fur regulated genes, which are essential for the survival of S. aureus in the host. The specific goals of this study are: 1) to identify Fur-regulated genes with the fur mutant and the parent strains using microarray analysis followed by northern blot analysis to confirm microarray data, 2) to determine the sequences of Fur binding site of 5-10 genes which are highly regulated by Fur-iron using EMSA and DNase protection assays, and 3) to construct mutations in at least 5 genes to determine their roles in pathogenic phenotype using a mouse kidney abscess model. It is hoped that the results of these studies may find yet unidentified Fur-regulated genes involved in the iron homeostasis and pathogenesis of S. aureus.

描述（由申请人提供）：金黄色葡萄球菌是人类疾病的主要原因。在该细菌中获得广泛的抗生素耐药性，尤其是甲氧西林和耐达霉素的金黄色葡萄球菌菌株对公共卫生构成了重大威胁。提出了宿主内部的各种应力条件，以刺激金黄色葡萄球菌中毒力基因的表达。铁已被证明是许多重要的毒力决定因素，并且对于许多重要的细胞过程所需，但对于动物宿主中的细菌细胞不易获得。为了应对铁缺陷的宿主环境，细菌已经发展出了铁采集调节的几种机制。我们已经克隆并表征了金黄色葡萄球菌的铁摄取调节基因（毛皮）。该基因代码为蛋白质，在足够的细胞内铁与位于Sira和Fhu启动子中的特定DNA序列结合并调节其表达（Xiong等，2000; Cabrera等，2001）。我们最近的DNA微阵列分析表明，许多基因都是通过铁差异表达的。这些基因是否直接或间接在毛铁的控制下，无法通过微阵列分析来区分。因此，我建议识别其中的一些基因，这些基因直接在毛皮调节的控制下并参与金黄色葡萄球菌的发病机理。这项研究的长期目的是鉴定毛皮调节的基因，这对于宿主中金黄色葡萄球菌的存活至关重要。 The specific goals of this study are: 1) to identify Fur-regulated genes with the fur mutant and the parent strains using microarray analysis followed by northern blot analysis to confirm microarray data, 2) to determine the sequences of Fur binding site of 5-10 genes which are highly regulated by Fur-iron using EMSA and DNase protection assays, and 3) to construct mutations in at least 5 genes to determine their roles in pathogenic phenotype using a mouse kidney脓肿模型。希望这些研究的结果可能会发现与铁稳态和金黄色葡萄球菌的发病机理有关的尚未确定的毛皮调节基因。