亚抑菌浓度左氧氟沙星对MRSA毒力基因和毒力调控基因mRNA表达水平的影响  

EFFECTS OF SUB-INHIBITORY CONCENTRATION OF LEVOFLOXACIN ON EXPRESSION OF VIRULENCE GENES AND VIRULENCE REGULATORY GENES OF MRSA

作　　者：英兰 额尔德木图[2] 王艳艳[3] 王俊瑞[3] YING Lan;E-er-de-mu-tu;WANG Yan-yan(Clinical Laboratory,The Fourth Hospital of Inner Mongolia,Hohhot 010020 China)

机构地区：[1]内蒙古第四医院检验科,内蒙古呼和浩特010020 [2]内蒙古医科大学 [3]内蒙古医科大学附属医院

出　　处：《内蒙古医科大学学报》2018年第3期268-273,共6页Journal of Inner Mongolia Medical University

基　　金：内蒙古自然科学基金面上项目(2016MS0829)

摘　　要：目的:探究亚抑菌浓度左氧氟沙星对甲氧西林耐药金黄色葡萄球菌临床株毒力基因表达的影响效应,为更合理使用喹诺酮类抗生素治疗多重耐药细菌感染提供新的实验依据和思路。方法:以5株甲氧西林耐药金黄色葡萄球菌临床分离株为研究对象,采用1.6μg/mL(MIC_(1/10))、8μg/mL(MIC_(1/2))亚抑菌浓度左氧氟沙星与其体外共培养6h,采用扫描电镜技术观察不同组金黄色葡萄球菌形态特征变化,采用荧光定量PCR方法检测各组MRSA株毒力基因(纤维黏连蛋白A、葡萄球菌蛋白A、α溶血素、杀白细胞毒素D和E)mRNA表达水平的变化。结果:体外共培养6 h时,1.6μg/mL(MIC_(1/10))、8μg/mL(MIC_(1/2))亚抑菌浓度左氧氟沙星MRSA组菌体均出现不同程度破碎和裂解,其毒力基因(spa、hla、luk-D和luk-E)mRNA表达水平均明显低于对照组(P<0.01),fnb A和sea 2个毒力基因在培养6 h时未能检测到其表达。结论:亚抑菌浓度左氧氟沙星对MRSA临床株仍具有一定杀伤活性,且可显著抑制MRSA多种毒力基因的表达。Objective：To explore the effects of sub-inhibitory concentration of levofloxacin on expression of virulence genes and virulence regulatory genes of MRSA strains,and to provide experimentalbasis and idea for reasonable guiding quilones usage in treatment of multi-drug resistant bacteria infection.Methods：Five methicillin resistant resistant Staphylococcus aureus clinical isolates were used assubjects,which were cultured with 1.6μg / mL（MIC1/ 10）and 8μg / mL（MIC1/ 2）concentration of levofloxacin for 6 hours.Then,scanning electron microscopy technique was used to observe the morphologicalchanges of MRSA strains in different groups,and real-time flurorescent quantitative PCR technique wasemployed to detect the expression levels of virulence genes and virulence regulatory genes,including fibronectin A（fnbA）,α-hemolysin（hla）,leukocidin D（luk-D）,E（luk-E）,staphylococcal protein A（spa）and enterotoxinA.Results：At 6 hours of co-culture,Staphylococcus aureus showed tatterring andsplitting at different degrees for 1.6μg / mL（MIC1/ 10）and 8μg / mL（MIC1/ 2）levofloxacin groups.Compa ring with control group,the mRNA expression levels of spa,hla,luk-D and luk-E of MRSA strains inthe above two experimental groups were significantly higher（P〈0.01）,and the mRNA expression of spaand sea was not detected.Conclusion：Sub-inhibitory concentration of levofloxacin shows bactericidalactivity at some degree,and can significantly suppress the expression of multiple virulence genes andvirulence regulatory genes.

关 键 词：金黄色葡萄球菌 毒力基因 左氧氟沙星 亚抑菌浓度 

分 类 号：R967[医药卫生—药理学]