Identification of the up- and down-regulated genes in vancomycin-resistant Staphylococcus aureus strains Mu3 and Mu50 by cDNA differential hybridization method
Identification of the up- and down-regulated genes in vancomycin-resistant Staphylococcus aureus strains Mu3 and Mu50 by cDNA differential hybridization method
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DOI：
10.1006/bbrc.2000.2277
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发表时间：
2000-03-16
影响因子：
3.1
通讯作者：
Hiramatsu, K
中科院分区：
文献类型：
--
作者：
Kuroda, M;Kuwahara-Arai, K;Hiramatsu, K
我们之前报道了第一个耐万古霉素金黄色葡萄球菌（VRSA）临床菌株Mu50，其细胞壁由于细胞壁合成的激活而显着增厚。为了探索万古霉素耐药的遗传基础，我们从一组对万古霉素不同程度敏感的近缘金黄色葡萄球菌菌株中提取rna，进行cDNA差异杂交。菌株为Mu3 （MIC = 2 μ g/ml）、Mu50 （MIC = 8 μ g/ml）和Mu50的易感反变菌株Mu50w （MIC = 0.5 μ g/ml）。在这项研究中，我们发现了一种新的应答调节因子，命名为vraR（代表万古霉素耐药相关基因R），与Mu50w相比，其转录在Mu3和Mu50中显著上调。在万古霉素敏感菌株N315P中过表达VraR可提高该菌株对万古霉素的耐药性。此外，编码果糖利用、脂肪酸代谢和两个假定的atp结合盒（ABC）转运体基因的基因在Mu3和Mu50中被发现上调。另一方面，与Mu3和Mu50w相比，Mu50中蛋白A的表达受到抑制。我们认为应答调节因子vraR是调控金黄色葡萄球菌万古霉素耐药水平的关键调节因子之一。假定果糖摄取的增加和脂肪酸代谢的改变也可能通过为细胞壁合成提供更多的前体代谢物来促进万古霉素耐药性。(C) 2000年学术出版社。
We previously reported the first vancomycin-resistant Staphylococcus aureus (VRSA) clinical strain, Mu50, whose cell wall is remarkably thickened resulting from the activation of cell-wall synthesis. To explore the genetic basis for the vancomycin resistance, cDNA differential hybridization was performed using: RNAs extracted from a set of closely related S. aureus strains with various levels of vancomycin susceptibilities. The strains were Mu3 (MIC = 2 mu g/ml), Mu50 (MIC = 8 mu g/ml), and a susceptible revertant of Mu50, Mu50w (MIC = 0.5 mu g/ml). in this study, we report identification of a novel response regulator, designated vraR (standing for vancomycin-resistance associated gene R) whose transcription was remarkably up-regulated in Mu3 and Mu50 as compared to Mu50w. Experimental over-expression of VraR in vancomycin-susceptible strain N315P raised vancomycin resistance of the strain. Also, the genes coding for fructose utilization, fatty acid metabolism and two putative ATP-binding cassette (ABC) transporter genes were found to be up-regulated in Mu3 and Mu50. On the other hand, Protein A expression was suppressed in Mu50, as compared with Mu3 and Mu50w. We consider that the response regulator vraR is one of the key regulators modulating the level of vancomycin-resistance in S. aureus. Presumed increased uptake of fructose and altered fatty acid metabolism may also contribute to vancomycin resistance by supplying more precursor metabolites for cell-wall synthesis. (C) 2000 Academic Press.