南方医科大学学报

南方医科大学学报 ›› 2006, Vol. 26 ›› Issue (01): 117-121.

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ΔLuxS的表型分析及其在GBS毒力调控机制研究中的应用

欧阳谦;马文丽;刘翠华;石嵘;郑文岭;   

  1. 南方医科大学基因工程研究所； 华南基因组中心 广东 广州 510515； 广东 广州 510515； 广东 广州 510800；
  • 出版日期:2006-01-20 发布日期:2006-01-20

Phenotypic analysis of luxS gene deletion mutants and its application in virulence regulation research in group B Streptococcus

OUYANG Qian, MA Wen-li, LIU Cui-hua, SHi Rong, ZHENG Wen-ling Institute of Genetic Engineering, Southern Medical University, Guangzhou 510515, China; South China Genome Center, Guangzhou 510800, China   

  1. 南方医科大学基因工程研究所； 华南基因组中心 广东 广州 510515； 广东 广州 510515； 广东 广州 510800；
  • Online:2006-01-20 Published:2006-01-20

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摘要： 目的采用LuxS缺失突变株模型对B型链球菌中数量感应相关分子LuxS的功能及与其相关的自诱导因子-2 数量感应通路进行研究,以探索其毒力调控机制。方法采用RT-PCR法、菌落印迹分析、生长曲线测定、cAMP因子测定等方法对该缺失突变菌株的表型特性进行了研究。最后应用哈氏弧菌作为报告菌株,通过生物发光测定法分析了突变株对B型链球菌诱导报告菌株中的生物发光活性的影响。结果发现此缺失突变可导致B型链球菌中scpB基因表达的上调;与野生株相比,突变株的生物发光诱导活性比野生株降低了大约两倍。结论本研究结果证实了LuxS在 GBS中AI-2数量感应通路中的重要性,并为GBS中毒力调控机制的进一步研究提供了新的线索。 更多还原

Abstract: Objective To explore the mechanism of virulence regulation in group B streptococcus (BGS) by studying LuxS-re-lated AI-2 quorum-sensing pathway in GBS. Methods luxS gene deletion mutants of GBS (△ lusX) were characterized by reverse transcription (RT)-PCR, colony immunoblot analysis, growth curve measurment, and cAMP determination. Functional analysis of luxS in the deletion mutants was conducted by bioluminescence assay. Results Genetic analysis results showed that the luxS deletion in the mutant 515-△lusX caused upregulation of scpB gene expression. Phenotypic analysis revealed that, in comparison with the wild strain, 515-△lusX mutant grew slowly in CDM media but quickly in THY media. An approximately two-fold decrement in bioluminescence was detected in the luxS deletion mutants as compared with the wild strain. Conclusion This study confirms the importance of LuxS molecule in the AI-2 quorum-sensing pathway in GBS and provides new insights into the virulence regulation mechanism of GBS.

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