南京某医院2013~2021年耐碳青霉烯大肠埃希菌对多粘菌素B的敏感性及耐药机制分析  

An Analysis of Polymyxin B Susceptibility and Resistance Mechanisms in Carbapenem-resistant Escherichia coli(CREC)at a Hospital in Nanjing from 2013 to 2021

作　　者：谢晖 曹小利 高硕 XIE Hui;CAO Xiaoli;GAO Shuo(Department of Laboratory Medicine,Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University,Nanjing 210008,China)

机构地区：[1]南京鼓楼医院医学检验科,江苏南京210008

出　　处：《标记免疫分析与临床》2025年第2期382-386,416,共6页Labeled Immunoassays and Clinical Medicine

基　　金：国家自然科学基金(编号:81902124)。

摘　　要：目的分析南京某医院2013~2021年耐碳青霉烯大肠埃希菌(carbapenem-resistant Escherichia coli,CREC)对多粘菌素的敏感性,并解析其耐药机制。方法收集2013~2021年的CREC菌株,通过微量肉汤稀释法评估其对多粘菌素B的敏感性。对于多粘菌素B不敏感的菌株,提取细菌DNA进行全基因组测序,分析多粘菌素耐药基因的分布,并对与多粘菌素耐药相关的基因mgrB、phoP、phoQ、pmrB和pmrA基因的突变情况进行分析,探讨基因突变与多粘菌素B最低抑菌浓度(minimum inhibitory concentration,MIC)值之间的关系。结果在100株CREC菌株中,23株细菌对多粘菌素B耐药,其中12株携带mcr-1基因。在其余的11株细菌中,所有细菌均存在pmrA和pmrB基因的突变,分别以Ser29Gly和Asp283Gly突变为主,8株细菌同时存在phoP基因的突变,突变类型均为Ile44Leu,两株细菌同时存在phoP、phoQ、pmrB和pmrA 4个基因的突变。结论在CREC菌株中,mcr基因的存在以及mgrB、phoP、phoQ、pmrB和pmrA基因的突变对多粘菌素的MIC值有显著影响。Objective To analyze the susceptibility of carbapenem-resistant Escherichia coli(CREC)to polymyxin in our hospital from 2013 to 2021 and to further elucidate the underlying mechanisms of resistance.Methods CREC strains collected from our hospital between 2013 and 2021 were analyzed for sensitivity to polymyxin B using the broth microdilution method.For strains that were not sensitive to polymyxin,bacterial DNA was extracted for whole-genome sequencing to identify the distribution of polymyxin resistance genes.Mutations in genes associated with polymyxin resistance(mgrB,phoP,phoQ,pmrB,and pmrA)were also analyzed to investigate the relationship between gene mutations and polymyxin MIC values.Results Among the 100 CREC isolates,23 were resistant to polymyxin B,and 12 of them carried mcr-1 gene.Among the remaining 11 strains,all had mutations in pmrA and pmrB genes,Ser29Gly and Asp283Gly mutations,while 8 strains had mutations in phoP gene at the same time.The mutation type was Ile44Leu.Mutations in phoP,phoQ,pmrB and pmrA genes were found in both strains.Conclusion In CREC strains,the presence of the mcr gene and mutations in the mgrB,phoP,phoQ,pmrB,and pmrA genes could significantly impact the MIC values of polymyxin.

关 键 词：大肠埃希菌 多粘菌素耐药 敏感性 耐药机制 突变 

分 类 号：R378[医药卫生—病原生物学]