亚胺培南体外诱导大肠埃希菌MIC变化规律及相关耐药机制探讨  

Changes in and mechanisms of imipenem-induced resistance of Escherichia coli in vitro

作　　者：刘慧莹[1] 陈帅印[1] 段广才[1,2] 梁文娟[2,3] 徐亚珂 龙金照 杨海燕 郗园林[1] LIU Hui-ying1 , CHEN Shuai-yin1, LIANG Wen-juan2,3, DUAN Guang-cai1,2, XU Ya-ke1, LONG Jin-zhao1, YANG Hai-yan1, XI Yuan-lin1(1. Department of Epidemiology and Health Statistics, Collegeof Public Health, Zhengzhou University, City of Zhengzhou , Henan Province, China ; 2. Henan Center for Innovation in Molecular Diagnosis and Laboratory Medicine, Xinxiang Medical University ; 3, Department of t？,pidemiology and Health Statistics, College of Public Health, Xinxiang Medical Universit)

机构地区：[1]郑州大学公共卫生学院流行病学教研室,河南郑州450001 [2]新乡医学院分子诊断与医学检验技术河南省协同创新中心 [3]新乡医学院公共卫生学院流行病与卫生统计教研室

出　　处：《中国病原生物学杂志》2018年第2期155-159,共5页Journal of Pathogen Biology

基　　金：国家科技重大专项(No.2013ZX10004607);郑州大学青年教师启动资金项目(No.32210273)

摘　　要：目的探讨亚胺培南(imipenem,IMP)体外诱导大肠埃希菌(Escherichia coli)耐药产生的变化规律及其相关的耐药机制。方法对2014年河南睢县某医院分离的全敏感E.coli用IMP进行体外浓度递增诱导,记录每个浓度下的诱导时间和诱导结束后的MIC值及其对应的累积时间,采用统计分析软件SPSS17.0对数据进行回归分析;采用改良Kirby-Bauer(K-B)纸片法测定诱导前后菌株对20种抗生素耐药谱的变化情况;采用聚合酶链式反应(polymerase chain reaction,PCR)扩增碳青霉烯酶类、β-内酰胺类等相关耐药基因并进行测序分析。结果体外诱导结束后菌株对IMP由敏感变为耐药。回归分析显示随着IMP诱导浓度的增加,诱导耐药时间延长,当浓度增加到一定数值时,诱导时间不再延长;回归分析显示,随着诱导浓度的增加或诱导时间的延长,MIC均逐渐增加,但两种情况下其增长率不同。诱导后的菌株对IMP耐药,对其他抗生素仍敏感,PCR扩增相关耐药基因均阴性。结论 IMP可诱导E.coli产生耐药,且随诱导浓度的增加诱导耐药时间先增加后达到平台期,而MIC持续增加。推测E.coli IMP耐药机制与某种特异靶位突变有关。Objective To examine changes in and potential mechanisms of imipenem-induced resistance of Escherichia coli in vitro. Methods Increasing doses of IMP were used to induce resistance in Sx181 strains of sensitive E.coli isolated from hospitals in Sui County（Henan Province,2014）in vitro.After induction of drug resistance,the time for induction of resistance,the minimum inhibitory concentration（MIC）,and the cumulative time for induction of resistance were recorded.Data were analyzed using SPSS17.0,and regression analysis was performed.The modified Kirby-Bauer（K-B）method was used to determine changes in the resistance spectrum of strains before and after induction of resistance to 20 antibiotics.Genes related to carbapenemase and beta-lactamase production were amplified using apolymerase chain reaction（PCR）and then sequenced. Results IMP induced resistance in the Sx181 strain.Its MIC changed from 0.125μg/ml to 64μg/ml.The time for induction of resistance to IMP increased in a dose-dependent manner.As the concentration of IMP increased,the time for induction of resistance stopped increasing.The regression equation for the time for induction of resistance（y）and the concentration for induction of resistance（x）was y=112.218＋44.794 log2 x,and R2 for the equation was 0.778.The MIC tended to increase as the concentration and time for induction of resistance increased.Growth rates differed widely with different concentrations and times for induction of resistance.The regression equation for MIC（y）and the concentration for induction of resistance（x）was y=2.375 x0.903,with R2=0.988,and the regression equation for MIC（y）and the time for induction of resistance（x）was y=20.06 x,with R2=0.823.The Sx181 strain of E.coli was resistant to IMP,but it remained sensitive to other antibiotics even after becoming resistant to IMP.Drug resistance genes were not detected.Conclusion IMP induces resistance in E.coli.As the concentration for induction of resistance to IMP increases,the time for induct

关 键 词：大肠埃希菌 亚胺培南 体外诱导 耐药机制 

分 类 号：R378.21[医药卫生—病原生物学]