Impact of the RNA chaperone Hfq on multidrug resistance in Escherichia coli.
Impact of the RNA chaperone Hfq on multidrug resistance in Escherichia coli.
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DOI：
10.1093/jac/dkq067
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发表时间：
2010-05
期刊：
影响因子：
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通讯作者：
J. Yamada;S. Yamasaki;Hidetada Hirakawa;Mitsuko Hayashi-Nishino;A. Yamaguchi;K. Nishino
中科院分区：
文献类型：
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作者：
J. Yamada;S. Yamasaki;Hidetada Hirakawa;Mitsuko Hayashi-Nishino;A. Yamaguchi;K. Nishino
目的 Hfq 是一种细菌 RNA 伴侣，通过小非编码 RNA 参与许多应激诱导基因的转录后调节。尽管 Hfq 与许多细菌病原体的毒力等重要表型相关，但其在耐药性中的作用尚不清楚。本研究的目的是探讨 Hfq 在细菌多药耐药性中的作用。方法使用pKO3（一种基因替换载体）在大肠杆菌中灭活hfq 基因。测定hfq突变体的药物敏感性和药物蓄积。还测量了该突变体中 AcrB 多药外排泵的产生水平。结果 hfq突变体对吖啶黄、苯扎氯铵、头孢孟多、氯霉素、结晶紫、萘啶酸、新生霉素、苯唑西林和罗丹明6G敏感。与删除 hfq 的野生型相比，大肠杆菌细胞被罗丹明 6G 强烈染色，表明 Hfq 影响药物在细菌细胞中的积累。药物流出基因 acrB 的缺失会削弱 hfq 缺失对大肠杆菌敏感性的影响。此外，hfq突变体中AcrB蛋白的产生水平降低，而hfq缺失并不影响acrAB操纵子的启动子活性。结论这些结果表明Hfq在转录后水平调节药物流出系统，并揭示了Hfq在细菌多药耐药性中先前未表征的作用。
OBJECTIVES Hfq is a bacterial RNA chaperone involved in the post-transcriptional regulation of many stress-inducible genes via small non-coding RNAs. Although Hfq is related to important phenotypes including virulence in many bacterial pathogens, its role in drug resistance is unknown. The aim of this study was to investigate the role of Hfq in bacterial multidrug resistance. METHODS The hfq gene was inactivated in Escherichia coli by use of pKO3, which is a gene replacement vector. The drug susceptibility and drug accumulation of the hfq mutant were determined. The level of production of the AcrB multidrug efflux pump in this mutant was also measured. RESULTS The hfq mutant was susceptible to acriflavine, benzalkonium, cefamandole, chloramphenicol, Crystal Violet, nalidixic acid, novobiocin, oxacillin and rhodamine 6G. E. coli cells were strongly stained with rhodamine 6G compared with the wild-type on deletion of hfq, indicating that Hfq affects the accumulation of the drug in bacterial cells. The deletion of the drug efflux gene acrB impairs the effect of hfq deletion on E. coli susceptibility. Furthermore, the level of AcrB protein production was reduced in the hfq mutant, whereas hfq deletion did not affect the promoter activity of the acrAB operon. CONCLUSIONS These results indicate that Hfq regulates the drug efflux system at the post-transcriptional level and reveals the previously uncharacterized role of Hfq in bacterial multidrug resistance.