3种抗菌药物诱导改变marA、soxS和robA基因mRNA表达水平

The Changes of marA,soxS and robA Gene Expression Levels in Three Kinds of Antimicrobial Agents Induced Resistant Mutants in vitro

本研究旨在探讨不同类抗菌药物诱导引起大肠肝菌主动外排系统调控基因marA、soxS、robA表达水平的变化特点。挑选大肠杆菌标准菌株O78经阿米卡星(AMK),环丙沙星(CIP),头孢曲松钠(CRO)逐代诱导的10、20、30代菌株作为试验菌株,提取其总RNA并反转录,采用荧光定量RT-PCR的方法测定其主动外排调控基因marA、soxS、robA的mRNA表达水平。结果表明:marA基因在CIP20中mRNA的表达水平最高,是母体菌株O78的2.30倍,且其在CIP10、CRO30、CIP30、AMK20的表达量分别为母体菌株O78表达量的2.11、1.71、1.15、1.44倍;soxS基因在AMK20中的表达量最高,是母体菌株的5.98倍,其它高于O78的菌株表达量的菌株为CRO30、CRO20、CIP20、CIP30;robA基因mRNA表达量除了在CIP10的表达量高于O78外,其余均低于母体菌株的表达。结果提示头孢曲松、环丙沙星、阿米卡星能诱导菌株的主动外排调控基因marA、soxSmRNA表达增加,robA基因mRNA表达减少。

The research was conducted to investigate the changes characteristics of the expression level of active efflux system regulatory genes（marA,soxS and robA） in Escherichia coli O78which induced by different antimicrobial agents.Extracted the total RNA of the 10th,20th,30th generations of ceftriaxone induced resistant mutants,ciprofloxacin induced resistant mutants and amikacin induced resistant mutants respectively.The mRNA expression levels of active efflux system regulatory genes,such as marA,soxS and robA were determined by reverse transcription real-time fluorescence quantitative PCR.The result showed that the mRNA expression level of marA gene in CIP20 was the highest,it was 2.30 times compared with the parent strain,and in CIP10,CRO30,CIP30,AMK20 were 2.11,1.71,1.15,1.44 respectively;The soxS gene expression level in AMK20,CRO30,CRO20,CIP20 and CIP30 were higher than O78,AMK20 was the highest one,which was 5.98 times of O78;Concerning the expression of robA genes,except CIP10 was increasing,all the other strains was decreased when compared with O78.The results indicated that ceftriaxone sodium,ciprofloxacin and amikacin can induce the expression of marA,soxS gene increased,robA gene decreased.