Identification of the agr locus of Listeria monocytogenes:: Role in bacterial virulence
Identification of the agr locus of Listeria monocytogenes:: Role in bacterial virulence
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DOI：
10.1128/iai.71.8.4463-4471.2003
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发表时间：
2003-08-01
影响因子：
3.1
通讯作者：
Charbit, A
中科院分区：
文献类型：
--
作者：
Autret, N;Raynaud, C;Charbit, A
单核细胞增生李斯特菌是一种革兰氏阳性兼性胞内食源性病原体，可引起人类和动物的严重感染。我们最近采用了标记转座子诱变（STM）来鉴定与L。单核细胞增多症新一轮的STM使我们能够确定一个新的基因座，该基因座编码与AgrA同源的蛋白质，AgrA是金黄色葡萄球菌的反应调节因子，也是参与细菌毒力的双组分系统的一部分。在L. agrA突变体中，几种分泌蛋白的产生被修饰。培养液中生长的单核细胞增多症，表明agr基因座影响蛋白质分泌。agrA的失活并不影响病原体在体外细胞中侵入和繁殖的能力。然而，agrA突变体在小鼠中的毒力减弱（静脉注射途径的50%致死剂量增加10倍），首次证明agr基因座在L.单核细胞增多症
Listeria monocytogenes is a gram-positive facultative intracellular food-borne pathogen that can cause severe infections in humans and animals. We have recently adapted signature-tagged transposon mutagenesis (STM) to identify genes involved in the virulence of L. monocytogenes. A new round of STM allowed us to identify a new locus encoding a protein homologous to AgrA, the well-studied response regulator of Staphylococcus aureus and part of a two-component system involved in bacterial virulence. The production of several secreted proteins was modified in the agrA mutant of L. monocytogenes grown in broth, indicating that the agr locus influenced protein secretion. Inactivation of agrA did not affect the ability of the pathogen to invade and multiply in cells in vitro. However, the virulence of the agrA mutant was attenuated in the mouse (a 10-fold increase in the 50% lethal dose by the intravenous route), demonstrating for the first time a role for the agr locus in the virulence of L. monocytogenes.