大肠埃希菌对喹诺酮类药物的耐药机制分析  

Resistance mechanism of Escherichia coli to quinolones

作　　者：石磊[1] 段博文 高进贤[1] 于静[1] 赵佩[1] SHI Lei DUAN Bo-wen GAO Jin-xian YU Jing ZHAO Pei(Gansu Provincial People＇s Hospital, Lanzhou, Gansu 730000, Chin)

机构地区：[1]甘肃省人民医院药剂科,甘肃兰州730000

出　　处：《中华医院感染学杂志》2017年第20期4568-4571,共4页Chinese Journal of Nosocomiology

基　　金：甘肃省科技厅资助项目(1606RJAZ/38)

摘　　要：目的分析大肠埃希菌对喹诺酮类药物的耐药机制。方法菌株来源于2013年1月-2016年12月医院患者分离的大肠埃希菌348株,排除同一患者同一部位分离出的重复病原菌,采用琼脂稀释法,按照《美国临床实验室标准协会》(CLSI)2007年标准计算分离菌株的最低抑菌浓度值(MIC)。筛选出耐药菌株,加入7种常用抗菌药物,测定其他抗菌药物对喹诺酮类耐药菌株的药敏情况。提取耐药大肠埃希菌株的DNA,加入适宜引物,进行扩增,并进行比对分析。结果在分离的大肠埃希菌中为喹诺酮类非敏感菌株87株占25.00%,87株喹诺酮类非敏感菌株对庆大霉素、阿米卡星、头孢噻肟、头孢吡肟、头孢曲松、头孢他啶6种抗菌药物的耐药率均超过50.00%。大肠埃希菌中gryA耐药基因的突变主要发生于低水平的MIC耐药菌株,而parC和PMQR的耐药基因均主要发生在MIC值在4~8μg/ml、16~64μg/ml两个浓度区间的耐药菌株。gryA基因S83L、D87N两个位点,及gryC基因的S80I、A108V两个位点的突变情况在MIC值各个范围内突变发生情况无显著性差异。结论喹诺酮类抗菌药物非敏感的大肠埃希菌对很多其他的抗菌药物也具有耐药性,大肠埃希菌中的耐药基因同喹诺酮类抗菌药物的MIC值分布上具有一定的相关性。OBJECTIVE To investigate the resistance mechanism of Escherichiacolito quinolones.METHODS The clinical isolates were derived from 348 isolates of E.coli isolated from our hospital from Jan.2013 to Dec.2016,and the repeated strains isolated from the same part of the same patient were excluded.The agar dilution method was used,and the MIC value of the isolate was calculated according to CLSI 2007.The resistant strains were screened out,and 7 kinds of common antimicrobial agents were added to determine the antimicrobial susceptibility of quinolones-resistant strains to other antimicrobial agents.The DNA of drug-resistant E.coli strains was extracted,the appropriate primers were added for amplification,and they were taken for comparison and analysis.RESULTS In the 348 isolates of E.coli,87 strains were quinolones non-sensitive strains,accounting for 25.00%.The resistant rates of 87 strains of quinolones non-sensitive strains to gentamicin,amikacin,cefotaxime,cefepime,ceftriaxone,and ceftazidime were all more than 50%.The mutations of gryAresistance gene in E.coli were mainly occurred in low level MIC resistant strains.The drug resistance genes of parCand PMQR were mainly occurred in the resistant strains with MIC values of 4~8μg/ml and 16~64μg/ml.There were no significant differences in mutations between the two sites of S83L and D87N of gryAgene and S80I and A108V of gryCgene in the range of MIC value.CONCLUSION The non-sensitive E.coli of quinolone antibiotics are also resistant to many other antibiotics.The resistance gene of E.coli has some correlation with the distribution of MIC value of quinolone antibiotics.

关 键 词：喹诺酮类药物 大肠埃希菌 耐药机制 

分 类 号：R378.21[医药卫生—病原生物学]