生物技术通报 ›› 2024, Vol. 40 ›› Issue (2): 55-64.doi: 10.13560/j.cnki.biotech.bull.1985.2023-0841

• 技术与方法 • 上一篇    下一篇

CRISPR/Cas9介导的adeG基因敲除大肠杆菌细菌模型的建立

朱恬仪1,2(), 孔桂美1,2(), 焦红梅1,2, 郭停停1,2, 乌日汗1,2, 刘翠翠1,2, 高成凤1,2, 李国才1,2()   

  1. 1.扬州大学医学院,扬州 225100
    2.江苏省人兽共患病学重点实验室,扬州 225100
  • 收稿日期:2023-08-29 出版日期:2024-02-26 发布日期:2024-03-13
  • 通讯作者: 孔桂美,女,博士,副教授,硕士生导师,研究方向:病原微生物;E-mail: gmkong@yzu.edu.cn
    李国才,男,博士,教授,博士生导师,研究方向:医学微生物学;E-mail: gcli@yzu.edu.cn
  • 作者简介:朱恬仪,女,硕士研究生,研究方向:病原生物学;E-mail: 15705273927@163.com
  • 基金资助:
    国家自然科学基金项目(82073611);江苏省人兽共患病学重点实验室开放课题(R2001)

Establishment of A Bacterial Model of CRISPR/Cas9 Mediated adeG Gene Knockout in Escherichia coli

ZHU Tian-yi1,2(), KONG Gui-mei1,2(), JIAO Hong-mei1,2, GUO Ting-ting1,2, WU Ri-han1,2, LIU Cui-cui1,2, GAO Cheng-feng1,2, LI Guo-cai1,2()   

  1. 1. Medical College of Yangzhou University, Yangzhou 225100
    2. Jiangsu Key Laboratory of Zoonosis, Yangzhou 225100
  • Received:2023-08-29 Published:2024-02-26 Online:2024-03-13

摘要:

【目的】鲍曼不动杆菌(Acinetobacter baumannii, AB)是引起医院内感染的重要条件致病菌之一,耐药性AB是目前防治的棘手问题。细菌外排泵是引起耐药性的重要原因之一,拟通过PCR检测鲍曼不动杆菌耐药结节分化家族(resistance-nodulation-division,RND)外排泵基因adeLFGH的分布,探索其与耐药性的关系;建立adeG耐药基因模型,利用CRISPR/Cas9系统对其进行靶向敲除的初步研究。【方法】运用肉汤微量稀释法检测耐药性分布;PCR筛查13株临床分离多重耐药鲍曼不动杆菌adeLFGH外排泵基因并分析其分布;扩增RND外排泵关键基因adeG并构建耐药细菌模型;设计特异性sgRNA,利用CRISPR/Cas9系统进行靶向敲除,药敏实验检测其敲除效果。【结果】13株临床鲍曼不动杆菌对多黏菌素E敏感,对左氧氟沙星耐药率较低,仅为38.5%,对头孢他啶的耐药率为92.3%,对妥布霉素耐药率为84.6%,对其他临床常见药物耐药率均为100%。13株多重耐药鲍曼不动杆菌adeLFGH携带率为100%。药敏实验结果显示adeG模型耐药菌株的哌拉西林、替卡西林/克拉维酸以及哌拉西林/他唑巴坦由敏感转为耐药,氯霉素、美罗培南、米诺环素由敏感转为中介。特异性sgRNA介导CRISPR/Cas9系统靶向敲除效率不同。pCas9-sgRNA1(adeG)靶向后哌拉西林/他唑巴坦的耐药性得到了逆转,对妥布霉素、四环素、多西环素、米诺环素的耐药性也有不同程度的降低;pCas9-sgRNA2(adeG)和pCas9-sgRNA3(adeG)使哌拉西林/他唑巴坦由耐药恢复到了中介,但对其他药物的耐药性逆转效果并不显著。【结论】特异性 CRISPR/Cas9 系统可以特异性敲除耐药基因,提示可为耐药菌的治疗提供新的思路和方法。

关键词: CRISPR/Cas9, 耐药性, sgRNA, adeG

Abstract:

【Objective】 Acinetobacter baumannii is one of the important opportunistic pathogens that cause hospital infections, and the highly resistant A. baumannii is currently a thorny issue in prevention and treatment. Due to the fact that bacterial efflux pumps are one of the important causes of drug resistance, the distribution of the efflux pump gene adeLFGH in the resistance-nodulation-division(RND)of A.baumannii was detected by PCR to explore its relationship with drug resistance. Next, an adeG resistance gene model was established and preliminary targeted knockout studies using the CRISPR/Cas9 system was conducted. 【Method】 Broth microdilution method was used to detect drug resistance distribution of collected strains. PCR was to screen and analyze the distribution of adeLFGH efflux pump genes in 13 clinical isolates of multidrug-resistant A.baumannii. The key gene adeG of RND efflux pump was amplified and a model of adeG resistant bacteria was constructed. Specific sgRNA was designed, CRISPR/Cas9 system was used for targeted knockout, and drug sensitivity experiments were conducted to detect its knockout effect. 【Result】 13 clinical strains of A.baumannii were sensitive to polymyxin E, with a low resistance rate to levofloxacin, only 38.5%. The resistance rate to ceftazidime was 92.3%, the resistance rate to tobramycin was 84.6%, and the resistance rate to other common clinical drugs was 100%.The carrier rate of adeLFGH in 13 strains of multidrug-resistant A.baumannii was 100%. The drug sensitivity test results showed that the adeG model bacteria showed a transition from sensitive to resistant to piperacillin, ticarcillin/clavulanic acid, and piperacillin/tazobactam, while from sensitive to intermediary to chloramphenicol, meropenem, and minocycline. The targeted knockout efficiency of the CRISPR/Cas9 system mediated by specific sgRNA varies. The resistance of pCas9-sgRNA1(adeG)to piperacillin/tazobactam was reversed, and the resistance to tobramycin, tetracycline, doxycycline, and minocycline reduced to varying degrees. pCas9-sgRNA2(adeG)and pCas9-sgRNA3(adeG)restored the resistance of piperacillin/tazobactam from resistant to intermediary, but the reversal effect on other drugs was not significant. 【Conclusion】 The specific CRISPR/Cas9 system can specifically knock out drug-resistant genes and provide new ideas and methods for the treatment of drug-resistant bacteria.

Key words: CRISPR/Cas9, drug resistance, sgRNA, adeG