多重耐药鲍曼不动杆菌对替加环素不敏感的耐药机制研究  

Mechanism of tigecycline insensitivity of multidrug-resistant Acinetobacter baumannii

作　　者：郭俊妙 袁润奇 邓晓龙 毛璞[1,3] 邱桂霞 GUO Junmiao;YUAN Runqi;DENG Xiaolong;MAO Pu;QIU Guixia(Department of Healthcare-associated Infection Management,The First Affiliated Hospital of Guangzhou Medical University,Guangzhou 510120,China;Center of Clinical Laboratory,The First Affiliated Hospital of Guangzhou Medical University,Guangzhou 510120,China;State Key Laboratory of Respiratory Diseases,Guangzhou 510120,China;National Center for Respiratory Medicine,Guangzhou 510120,China;National Clinical Research Center for Respiratory Diseases,Guangzhou 510120,China;Guangzhou Institute of Respiratory Health,Guangzhou 510120,China)

机构地区：[1]广州医科大学附属第一医院医院感染管理科,广东广州510120 [2]广州医科大学附属第一医院医院临床检验中心,广东广州510120 [3]呼吸疾病全国重点实验室,广东广州510120 [4]国家呼吸医学中心,广东广州510120 [5]国家呼吸系统疾病临床研究中心,广东广州510120 [6]广州呼吸健康研究院,广东广州510120

出　　处：《中国感染控制杂志》2025年第1期45-51,共7页Chinese Journal of Infection Control

基　　金：广东省钟南山医学基金会新冠病毒肺炎防控专项项目(第二批)项目(ZNSA-2020012)。

摘　　要：目的探讨多重耐药鲍曼不动杆菌(MDR-AB)对替加环素不敏感的耐药机制,为临床合理用药及医院感染防控提供参考。方法收集2022年4月—2023年5月广州医科大学附属第一医院临床分离的替加环素不敏感MDR-AB(TIS-MDR-AB)及替加环素敏感MDR-AB(TS-MDR-AB)各22株。应用外排泵抑制剂羰基氰化物间氯苯腙(CCCP)进行外排泵表型抑制试验,采用聚合酶链式反应(PCR)技术对主要外排泵基因(ade B、ade G、ade J)和替加环素耐药基因tet(X)进行筛选,并应用实时荧光定量PCR检测其mRNA表达水平;Sanger测序分析外排泵调控基因ade RS的突变。结果两组MDR-AB外排泵基因ade B、ade G、ade J的检出率均>95%,未检测到tet(X)基因。外排泵抑制剂试验显示,TIS-MDR-AB菌株在加入CCCP后最低抑菌浓度(MIC)下降,且有3株菌株外排泵表型阳性。TIS-MDR-AB组MDR-AB ade B的mRNA表达水平高于TS-MDR-AB组(P<0.01),ade G和ade J基因的表达差异无统计学意义。ade R基因和ade S基因中发现多个突变,且有2株菌株ade S基因中插入ISA ba 1,3株菌株插入ISA ba 13。结论外排泵系统ade ABC过度表达可能在MDR-AB对替加环素敏感性下降机制中起重要作用,且其过度表达可能与外排泵调控基因ade RS中出现插入序列或突变有关。Objective To explore the resistance mechanism of tigecycline insensitivity of multidrug-resistant Acine-tobacter baumannii,and provide reference for clinical rational antimicrobial use as well as prevention and control of healthcare-associated infection.Methods 22 strains of tigecycline insensitive multidrug-resistant Acinetobacter baumannii(TIS-MDR-AB)and 22 strains of tigecycline sensitive multidrug-resistant Acinetobacter baumannii(TS-MDR-AB)isolated clinically from the First Affiliated Hospital of Guangzhou Medical University from April 2022 to May 2023 were collected.Efflux pump phenotype inhibition assay was performed using efflux pump inhibitor carbonyl cyanide m-chlorophenylhydrazone(CCCP).The main efflux pump genes(ade B,ade G,ade J),as well as tigecycline-resistant gene tet(X),were screened by polymerase chain reaction(PCR)technique,and their mRNA expression levels were detected by real-time fluorescence quantitative PCR.Mutations in the efflux pump regulatory gene ade RS were analyzed by Sanger sequencing analysis.Results The detection rates of efflux pump genes ade B,ade G and ade J were all above 95%in two MDR-AB groups,and tet(X)gene was not detected.Efflux pump inhibitor assay showed that the minimum inhibitory concentration(MIC)of TIS-MDR-AB strains decreased after adding CCCP,3 strains showed positive efflux pump phenotype.The mRNA expression level of MDR-AB ade B in the TIS-MDR-AB group was higher than that in the TS-MDR-AB group(P<0.01),while the expression of ade G and ade J genes was no statistically different.Multiple mutations were found in the ade R and ade S genes,the ade S of 2 strains was inserted ISA ba 1,and 3 strains were inserted ISA ba 13.Conclusion The overexpression of ade ABC in the efflux pump system may play an important role in the mechanism of reduced sensitivity of MDR-AB to tigecycline,and its overexpression may be related to the insertion sequence or mutation in the efflux pump regulatory gene ade RS.

关 键 词：鲍曼不动杆菌 多重耐药 替加环素 RND外排泵 

分 类 号：R181.32[医药卫生—流行病学] R378[医药卫生—公共卫生与预防医学]