摘要
为了探索鼠伤寒沙门菌双组分信号系统CpxAR的应答调节蛋白基因cpxR对小鼠半数致死量(LD_(50))的影响,为下一步研究CpxAR系统对鼠伤寒沙门菌致病性的调控机制提供基础。本研究通过ERIC-PCR、MLST分型技术筛选流行克隆株JS_分,应用噬菌体转导技术构建基因缺失突变株JS_分△cpxR,并分别测定了小鼠腹腔注射JS_标、JS_标△cpxR、JS_分、JS_分△cpxR后的LD_(50)。结果显示:89株鼠伤寒沙门菌分为11个ERIC型、4个ST型,流行性克隆株为ST1920型(新的ST型)。LD_(50)结果显示,JS_标、JS_标△cpxR、JS_分、JS_分△cpxR对小鼠的LD_(50)分别为5.79×108、7.85×108、1.91×107、3.35×108 CFU。其中ST1920型代表株(JS_分)的LD_(50)较JS_标低约30.31倍,JS_标△cpxR突变株的LD_(50)比其亲本株JS_标升高了1.36倍,JS_分△cpxR突变株LD_(50)比其亲本株JS_分升高了17.54倍。结果表明cpxR基因缺失株毒力均明显下降,cpxR基因与鼠伤寒沙门菌毒力密切相关,对致病性有重要影响。
To explore the influence of cpxR gene of two-component signaling system in Salmonella enterica serovar typhimurium on the median lethal dose（LD（50））in mice and to provide the foundation for further research on its regulatory mechanism of Salmonellatyphimurium pathogenicity.This study screened the epidemic strain JSc（clinical isolates）by ERIC-PCR,the multi-locus sequence typing（MLST）and constructed the cpxR gene deletion mutant which named as JSc△cpxR by P22 phage transduction.Then the lethal dose（LD（50））of JSs（standard strains）,JSs△cpxR,JSc,JSc△cpxR strains in mice were determined.The results showed that 89 Salmonella enterica serovar typhimurium strains were grouped into 11 and 4patterns by ERIC-PCR and MLST,respectively.The ST of 33 isolate was identified as newly discovered ST-1920;The LD（50） of JSs,JSs△cpxR,JSc,JSc△cpxR strains in mice were 5.79×10^8 CFU,7.85×10^8 CFU,1.91×10^7 CFU,3.35×10^8 CFU,respectively.The LD（50） of the representative strain（JSc）of the new ST1920 decreased by about 30.31 times compared with that of JSs.The LD（50） of JSs△cpxR increased by about 1.36 times compared with that of its parent strain,while the LD（50） of JSc△cpxR increased by about 17.54 times compared with that of its parent strain,suggesting that the virulence of cpxR gene deletion strain become less virulent than that of the parent strain.In conclusion,cpxR gene is closely related to the pathogenicity of S.enterica serovar typhimurium and have important effects on the pathogenicity of S.enterica serovar typhimurium.
出处
《中国兽医学报》
CAS
CSCD
北大核心
2016年第3期437-442,共6页
Chinese Journal of Veterinary Science
基金
国家自然科学基金资助项目(31372481)
关键词
鼠伤寒沙门菌
应答调节蛋白基因cpxR
半数致死量
S.entericaserovar typhimurium
response regulator protein cpxR gene
the median lethal dose
