密度感应系统对弗氏志贺菌生长竞争能力的影响  

The effect of quorum sensing system for growth competitiveness on Shigella flexneri

作　　者：徐苹[1,2] 杨晶[2] 陆丽兰 冯尔玲[2] 王恒樑[1,2] 卢瑛[1] 朱力[2] 

机构地区：[1]上海海洋大学食品学院,上海201306 [2]军事医学科学院生物工程研究所,病原微生物生物安全国家重点实验室,北京100071

出　　处：《遗传》2015年第5期487-493,共7页Hereditas（Beijing)

基　　金：国家自然科学基金项目(编号:81171531,81125012,81373316);国家重点基础研究发展计划(“973”计划)项目(编号:2011CB504901,2013CB910804)资助

摘　　要：密度感应系统调节细菌应答反应的发生,这些应答反应与细胞密度有关。通过对比大肠杆菌(Escherichia coli)和志贺氏菌(Shigella spp.)的序列发现,志贺菌属密度感应系统操纵子普遍存在丢失或突变。为研究其密度感应系统的功能,文章利用哈氏弧菌(Vibrio harveyi)BB170作为指示菌,检测弗氏志贺菌(Shigella flexneri)密度感应系统信号分子AI-2,证明其可以分泌有活性的AI-2;其次,采用Golden Gate克隆法将大肠杆菌MG1655的密度感应系统基因克隆至弗氏志贺菌301中,获得密度感应系统回复株301。通过菌落计数表明,在混合培养条件下,密度感应系统基因回复株301比野生株301存在生长优势;通过双向电泳初步比较分析表明,密度感应系统基因可以在志贺菌中表达,并鉴定到了其他一些与应激反应相关的差异表达蛋白,如Hsp60、Gro EL、Sod B。Quorum sensing （QS） regulates the onset of bacterial social responses related to cell density. Compari- son between the gene sequences of all components of QS system of Escherichia coli and Shigella strains, shows that the QS system is generally lost or mutated in Shigella. Since AI-2 is produced and processed by the lsr operon, we analyzed the potential function of the lsr operon. We first detected AI-2 in Shigellaflexneri 2a strain 301 through the reporter bacteria Vibrio harveyi BB170, indicating that S. flexneri can produce AI-2. Then, the lsr operon of E. coli MG1655 was cloned into S. flexneri using the Golden Gate method. Colony counting experiments showed that the QS system recovery strain had growth advantage over the wild-type strain when they were mixed and cultured. The pre- liminary comparative proteomics analysis showed that the lsr operon could be expressed and the abundance of stress response proteins also changed when the QS system was introduced into S. flexneri.

关 键 词：弗氏志贺菌 密度感应系统 信号分子AI-2 比较蛋白质组学 

分 类 号：R378.25[医药卫生—病原生物学]