耐碳青霉烯类弗劳地柠檬酸杆菌的耐药基因及分子分型  

Antimicrobial resistance genes and molecular typing of carbapenem-resis-tant Citrobacter freundii

作　　者：林玉玲 陈清清[1] 彭芃芃 邱慧娜 胡丽萍 闫小利 张建明 LIN Yu-ling;CHEN Qing-qing;PENG Peng-peng;QIU Hui-na;HU Li-ping;YAN Xiao-li;ZHANG Jian-ming(Departments of Laboratory Medicine,Quanzhou First Hospital Affiliated to Fujian Medical University,Quanzhou 362000,China;Department of Laboratory Medicine,The Infectious Disease Hospital of Quanzhou City,Quanzhou 362100,China)

机构地区：[1]福建医科大学附属泉州第一医院检验科,福建泉州362000 [2]泉州市传染病防治医院检验科,福建泉州362100

出　　处：《中国感染控制杂志》2024年第12期1486-1491,共6页Chinese Journal of Infection Control

基　　金：泉州市科技局计划项目(2018Z052、2022NS061)。

摘　　要：目的分析耐碳青霉烯类弗劳地柠檬酸杆菌(CRCF)的检出率、分布特点、耐药机制及分子分型,为临床治疗与防控提供理论依据。方法分析2020—2023年福建医科大学附属泉州第一医院分离CRCF的药敏结果,验证菌株耐药表型,扩增耐药基因,多位点序列分型(MLST)分析菌株同源性,全基因组测序分析同时携带bla VIM-1、bla NDM-1的CF17菌株。结果共检出非重复弗劳地柠檬酸杆菌119株,其中CRCF 27株,占22.7%。CRCF主要分离自神经外科和泌尿外科,标本类型主要是中段尿;对碳青霉烯类和头孢菌素均耐药,对阿米卡星的耐药率较低,对替加环素及多黏菌素均敏感,对其余抗菌药物的耐药率>50%。成功复苏的22株CRCF耐药表型均阳性,均携带耐药基因,其中17株(77.3%)携带单耐药基因,包括14株bla NDM-1,2株bla KPC-2,1株bla NDM-5;5株(22.7%)同时携带双耐药基因,包括同时携带bla KPC-2、bla NDM-1(共3株),同时携带bla NDM-1、bla IMP和同时携带bla VIM-1、bla NDM-1(各1株);共检出8个ST型,ST116、ST532分别有8、6株。CF17为ST116,携带的bla VIM-1、bla NDM-1位于不同的质粒上,分别为IncA、IncX3。结论CRCF以多重耐药为主,主要耐药机制是携带bla NDM-1,部分菌株同时携带双耐药基因,以ST116和ST532为主,CF17是目前已知国内首次分离报告同时携带bla VIM-1及bla NDM-1耐药基因的弗劳地柠檬酸杆菌。Objective To analyze the detection rate,distribution characteristics,resistance mechanism,and molecular typing of carbapenem-resistant Citrobacter freundii(CRCF),providing theoretical basis for clinical treatment and prevention.Methods Antimicrobial susceptibility testing results of CRCF isolated from Quanzhou First Hospital Affiliated to Fujian Medical University from 2020 to 2023 were analyzed.Resistance phenotypes of the strains were verified;resistance genes were amplified;strain homology was analyzed by multi-locus sequencing ty-ping(MLST).Whole genome sequencing analysis was performed on CF17 strains carrying both bla VIM-1 and bla NDM-1.Results A total of 119 strains of non-repetitive Citrobacter freundii were detected,27 strains were CRCF,accounting for 22.7%.CRCF was mainly isolated from departments of neurosurgery and urology,and the specimen type was mainly midstream urine.Strains were resistant to both carbapenems and cephalosporins,less resistant to amikacin,susceptible to both tigecycline and polymyxin,and with a resistance rate of>50%to other antimicrobial agents.22 CRCF strains were successfully recovered and all were positive for antimicrobial resistance phenotype and genes.17 strains(77.3%)carried single resistance genes,including 14 strains carrying bla NDM-1,2 strains carrying bla KPC-2,and 1 strain carrying bla NDM-5.5 strains(22.7%)carried dual antimicrobial resistance genes,including strains carrying both bla KPC-2 and bla NDM-1(n=3),strain carrying both bla NDM-1 and bla IMP(n=1),and strain carrying both bla VIM-1 and bla NDM-1(n=1).A total of 8 ST types were detected,with 8 and 6 strains being ST116 and ST532,respectively.CF17 was ST116,carrying bla VIM-1 and bla NDM-1 on different plasmids,namely IncA and IncX3,respectively.Conclusion CRCF strains are mostly multidrug-resistant,with the presence of bla NDM-1 being the major resistance mechanism.Some strains also carry dual resistance genes,mainly ST116 and ST532.CF17 is currently the first isolated and reported Citrobacter freundii that

关 键 词：耐碳青霉烯类弗劳地柠檬酸杆菌 bla NDM-1 bla VIM bla IMP ST116 ST532 耐药性 碳青霉烯耐药基因 碳青霉烯酶 

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]