摘要/Abstract

摘要： 目的 ·观察严谨反应相关的 (p)ppGpp合成酶基因（ relA）对多黏菌素抗鲍曼不动杆菌异质性耐药的影响。方法 ·采用 Red同源重组技术敲除鲍曼不动杆菌 ATCC19606中 relA基因；用结晶紫染色法观察鲍曼不动杆菌菌膜形成的情况；用群体分析法（population analysis profiles，PAP）检测在多黏菌素作用下鲍曼不动杆菌产生异质性耐药菌落数的变化并计算异质性耐药率；用杀菌曲线检测在多黏菌素作用下鲍曼不动杆菌持留菌形成情况。结果 ·成功敲除鲍曼不动杆菌中 relA基因，获得 relA基因敲除株 ATCC19606-ΔrelA，鲍曼不动杆菌的菌膜形成量明显下降，多黏菌素作用下异质性耐药菌落数及持留菌形成量均显著性降低。结论 ·细菌严谨反应中 (p)ppGpp合成酶 relA基因可能是影响鲍曼不动杆菌对多黏菌素产生异质性耐药的重要因素。
关键词: 鲍曼不动杆菌, relA基因, 多黏菌素, Red同源重组技术, 异质性耐药, 持留性, 菌膜
Abstract:
Objective · To observe the effect of the (p)ppGpp synthase gene (relA) on the heteroresistance of colistin against Acinetobacter baumannii. Methods · The relA gene in Acinetobacter baumannii ATCC19606 was knocked outRed homologous recombination technique. The biofilm formation of Acinetobacter baumannii was observedcrystal violet staining. The change of heterogeneous colonies of Acinetobacter baumannii under the action of colistin was detectedpopulation analysis profiles (PAP) and the heterogeneity was calculated. The killing curve was used to detect the formation of persistent bacteria in Acinetobacter baumannii under the action of colistin. Results · The relA gene in Acinetobacter baumannii was successfully knocked out, and the relA knockout strain ATCC19606-ΔrelA was obtained. After relA gene knockout, the biofilm formation of Acinetobacter baumannii decreased significantly. After relA gene knockout, Acinetobacter baumannii significantly reduced the heterogeneous colonies and persistent bacteria formation under the action of colistin. Conclusion · The bacterial stringent reaction (p) ppGpp synthase relA may be an important factor affecting the heteroresistance of Acinetobacter baumannii to colistin.
Key words: Acinetobacter baumannii, relA gene, colistin, Red homologous recombination technology, heteroresistance, persistence, biofilm


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