House Cleaner Tolerance in S. aureus

许多家庭清洁剂(HC)是杀生剂/消毒剂混合物，含有植物精油提取物、洗涤剂、酒精和其他成分。我们的实验室已经证明，HCS可以选择对HC耐受性增加(Hct)且对重要的抗葡萄球菌药物万古霉素敏感性降低的金黄色葡萄球菌。实验还确定，体外选择的万古霉素中间体金黄色葡萄球菌(VISA)显示对HC的耐受性增加。综上所述，这些证据表明万古霉素耐药的机制和遗传学与Hct有关联。目前，HCT的身份和所有签证决定因素尚不清楚。我们还确定了两个相互作用的全球 调节剂参与了金黄色葡萄球菌的Hct机制。我们现在的主要目标是确定金黄色葡萄球菌的HC t决定因素，以及与HC应激反应和HC t“调节子”相关的染色体位点。 我们建议 1.鉴定Hct-表型，研究Hcs对细胞壁/膜的作用 超微结构。 2.通过以下方式确定HC t-决定因素和HC t调节子： 一、分析两个染色体全局调控因子的序列和调控； 二、Hct决定簇的直接克隆和筛选； 三、专注于由全球调节者控制的染色体基因座，并使用DNA亚阵列降低万古霉素的易感性；以及 四、利用金黄色葡萄球菌基因组DNA阵列研究Hct突变后金黄色葡萄球菌转录组的变化。 3.确定临床分离的金黄色葡萄球菌中是否存在Hct突变，并确定Hct是否存在 表型可用于检测对万古霉素敏感性降低的金黄色葡萄球菌。 我们假设金黄色葡萄球菌的HC耐受性是由一个全局调控因子操纵子/基因座的突变所介导的。 由于我们的证据表明万古霉素耐药的机制和遗传学与Hct有关，我们希望发现Hct基因座也与金黄色葡萄球菌的VISA机制有关。更重要的是，我们打算开发一种新的方法来检测临床分离株对万古霉素的低水平耐药性。 该项目还将阐明全球监管在针对多种细菌基因产品和过程的杀生剂的细菌反应中的作用。

Many home cleaners (HC) are biocide/disinfectant mixtures contain plant essential oil extracts, detergents, alcohols and other constituents. Our laboratory has demonstrated that HCs can select for Staphylococcus aureus strains with increased HC tolerance (HC t) and reduced susceptibility to the important anti-staphylococcal drug vancomycin. Experiments have also determined that in-vitro selected vancomycin-intermediate S. aureus (VISA) demonstrate increased tolerance to a HC. Collectively this evidence indicates that the mechanisms and genetics of vancomycin resistance and HC t are linked. Presently, the identity of the HCt and all the VISA determinants are unknown. We have also determined that two interacting global regulators are involved with the HC t mechanism in S. aureus. Our major goal now is to identify the HC t determinants of S. aureus and chromosomal loci associated with the HC-stress response and HC t "regulon''. We propose to 1. Characterize the HC t-phenotype and investigate the action of HCs on cell wall/membrane ultrastructure. 2. Identify HC t-determinants and the Hc t regulon via: i. analyzing sequences and regulation of two chromosomal global regulators; ii. direct cloning and selection of HC t-determinants; iii. focusing on chromosomal loci controlled by global regulators and involved with reduced vancomycin susceptibility using a DNA subarray; and iv. investigating alterations in the S. aureus transcriptome following HC t mutation utilizing S. aureus genomic DNA arrays. 3. Determine if HC t mutants are present among clinical S. aureus isolates and determine if HC t phenotype can be used to detect S. aureus with reduced susceptibility to vancomycin. We hypothesize that HC tolerance in S. aureus is mediated by mutations in a global regulator operon/loci. Since our evidence indicates that the mechanisms and genetics of vancomycin resistance and HC t are linked, we expect to find HC t loci that are also involved with the VISA mechanism of S. aureus. Whats more, we intend to develop a novel assay for the detection of low-level vancomycin resistance among clinical isolates. This project will also clarify the role of global regulation in the bacterial response to biocides that target multiple bacterial gene products and processes.