House Cleaner Tolerance in S. aureus

许多家用清洁剂（HC）是含有植物精油提取物、洗涤剂、酒精和其他成分的杀生物剂/消毒剂混合物。我们的实验室已经证明，HC可以选择具有增加的HC耐受性（HC t）和对重要的抗葡萄球菌药物万古霉素的敏感性降低的金黄色葡萄球菌菌株。实验还确定了体外选择的万古霉素中间体S。金黄色葡萄球菌（VISA）表现出对HC的耐受性增加。总的来说，这些证据表明万古霉素耐药的机制和遗传学与HC t相关。目前，HCt和所有VISA决定因素的身份尚不清楚。我们还确定了两个相互作用的全球 调节子参与了S.金黄色。我们现在的主要目标是确定S的HC t决定簇。金黄色葡萄球菌和与HC-应激反应和HC t“调节子”相关的染色体基因座。 我们建议 1.表征HC t-表型并研究HC对细胞壁/膜的作用 超微结构 2.通过以下方式识别HC t决定簇和HC t调节子： I.分析两个染色体全局调节子的序列和调节; 二.直接克隆和选择HC t-决定簇; 三.使用DNA子阵列，重点关注受全球监管机构控制并与万古霉素敏感性降低相关的染色体基因座;以及 四.调查S.利用S.金黄色葡萄球菌基因组DNA阵列。 3.确定临床S中是否存在HC t突变体。金黄色葡萄球菌分离株，并确定是否HC t 表型可用于检测S.金黄色葡萄球菌对万古霉素的敏感性降低。 我们假设，HC耐受性在S。金黄色葡萄球菌是由全局调节操纵子/基因座中的突变介导的。 由于我们的证据表明万古霉素耐药的机制和遗传学与HC t相关，我们期望找到同样参与S.金黄色。此外，我们打算开发一种新的检测临床分离株中低水平万古霉素耐药性的方法。 该项目还将阐明全球监管在细菌对针对多种细菌基因产物和过程的杀生物剂的反应中的作用。

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.