Xu Lin, Li Hualin, Vuong Cuong, Vadyvaloo Viveka, Wang Jianping, Yao Yufeng, Otto Michael, Gao Qian
Key Laboratory of Medical Molecular Virology, Shanghai Medical College, Fudan University, Shanghai 200032, People's Republic of China.
Infect Immun. 2006 Jan;74(1):488-96. doi: 10.1128/IAI.74.1.488-496.2006.
Nosocomial infections caused by Staphylococcus epidermidis are characterized by biofilm formation on implanted medical devices. Quorum-sensing regulation plays a major role in the biofilm development of many bacterial pathogens. Here, we describe luxS, a quorum-sensing system in staphylococci that has a significant impact on biofilm development and virulence. We constructed an isogenic DeltaluxS mutant strain of a biofilm-forming clinical isolate of S. epidermidis and demonstrated that luxS signaling is functional in S. epidermidis. The mutant strain showed increased biofilm formation in vitro and enhanced virulence in a rat model of biofilm-associated infection. Genetic complementation and addition of autoinducer 2-containing culture filtrate restored the wild-type phenotype, demonstrating that luxS repressed biofilm formation through a cell-cell signaling mechanism based on autoinducer 2 secretion. Enhanced production of the biofilm exopolysaccharide polysaccharide intercellular adhesin in the mutant strain is presumably the major cause of the observed phenotype. The agr quorum-sensing system has previously been shown to impact biofilm development and biofilm-associated infection in a way similar to that of luxS, although by regulation of different factors. Our study indicates a general scheme of quorum-sensing regulation of biofilm development in staphylococci, which contrasts with that observed in many other bacterial pathogens.
由表皮葡萄球菌引起的医院感染的特征是在植入式医疗设备上形成生物膜。群体感应调节在许多细菌病原体的生物膜形成中起主要作用。在此,我们描述了luxS,一种葡萄球菌中的群体感应系统,它对生物膜形成和毒力有重大影响。我们构建了一株表皮葡萄球菌生物膜形成临床分离株的同基因DeltaluxS突变株,并证明luxS信号传导在表皮葡萄球菌中起作用。该突变株在体外表现出生物膜形成增加,并且在生物膜相关感染的大鼠模型中毒力增强。基因互补和添加含自诱导物2的培养滤液恢复了野生型表型,表明luxS通过基于自诱导物2分泌的细胞间信号传导机制抑制生物膜形成。突变株中生物膜胞外多糖胞间粘附素产量的增加可能是观察到的表型的主要原因。先前已证明agr群体感应系统以与luxS类似的方式影响生物膜形成和生物膜相关感染,尽管是通过调节不同的因子。我们的研究表明了葡萄球菌中生物膜形成的群体感应调节的一般模式,这与在许多其他细菌病原体中观察到的模式形成对比。