摘要
目的:研究多黏菌素B(polymyxin,PB)刺激下,伤寒沙门菌mig-14基因的表达是否受调节因子Fis、OmpR、IHF、HilD激活。方法:用自杀质粒法分别制备hilD及IHF的α亚基编码基因(himA)和β亚基编码基因(himD)的缺陷株;然后通过实时定量PCR和lacZ融合实验比较PB刺激下mig-14在伤寒沙门菌各缺陷株(himA、himD、hilD、fis、ompR)与野生株中的转录水平差异,筛选出作用于mig-14的调控因子。结果:成功制备伤寒沙门菌himA、himD及hilD缺陷株;在多黏菌素B刺激下,实时定量PCR结果显示fis、ompR、himA、himD及hilD缺陷株中mig-14 mRNA水平明显低于野生株;lac Z融合实验中,fis、ompR、himA、himD及hilD缺陷株Miller Units值明显低于野生株。结论:在多黏菌素B刺激下,调节因子Fis、OmpR、IHF、HilD可激活伤寒沙门菌mig-14表达。
Objective：To investigate whether the expression of mig-14 in Salmonella enterica serovar Typhi（S.Typhi） depends on Fis, OmpR, IHF and HilD in the bacteria treated with polymyxin B（PB）.Methods：The homologous recombination mediated by suicide plasmid was used to knock out hilD, himA, himD of S.Typhi.qRT-PCR and lacZ fusion assay were used to compare the transcripitional level of mig-14 in the mutant strains（himA,himD, hilD, fis and ompR） with that of the wild-type strains of S.Typhi to identify the regulators of mig-14.Results：The hilD, himA and himD deletion mutants of S.Typhi were successfully constructed.The qRT-PCR results showed that when treated with PB, mRNA levels of mig-14 were significantly reduced in fis, ompR, hilD, himA and himD mutant strains compared with the wild-type strains.The results of lacZ fusion assay indicated that the promoter activities of mig-14 were also significantly decreased in fis, ompR, hilD, himA and himD mutant strains compared with the wild-type strains.Conclusion：Fis, OmpR, IHF and HilD could promote the expression of mig-14 in S.Typhi under the treatment of PB.
出处
《江苏大学学报（医学版）》
CAS
2017年第3期243-247,共5页
Journal of Jiangsu University：Medicine Edition
基金
国家自然科学基金资助项目(31000046)
国家博士后基金资助项目(2015M571702)
江苏大学高级人才启动基金资助项目(11JDG063)
