大肠埃希菌β-内酰胺酶基因分型与耐药性研究  

Genotype and Drug Resistance of β-Lactamases in Escherichia coli

作　　者：王淑峰[1] 戎建荣[2] Ian Booth 

机构地区：[1]山西医科大学第一医院检验科,山西太原030001 [2]山西省临床检验中心科研教学部,山西太原030012 [3]英国阿伯丁大学细胞与分子生物研究所

出　　处：《中华医院感染学杂志》2009年第17期2236-2238,共3页Chinese Journal of Nosocomiology

基　　金：山西省医学留学人员重点基金项目(20000940)

摘　　要：目的了解长期使用抗菌药物患者体内大肠埃希菌耐药基因及临床常用抗菌药物耐药的相关性。方法对分离的7株大肠埃希菌,作β-内酰胺酶测定、药物敏感试验、质粒DNA转化、等电点聚焦(IEF)电泳和DNA印迹试验。结果7株大肠埃希菌,均产生超广谱β-内酰胺酶(ESBLs),随着抗菌药物的持续使用,其相应最低抑菌浓度(MIC)值不断增高;IEF结果显示,7株大肠埃希菌均产TEM型β-内酰胺酶,其中3、4、5、6、7号菌株还产生TEM型酶以外的AmpC酶,而6、7号菌株除具备以上两种酶以外,还表现有SHV型β-内酰胺酶活性。结论从肝脓肿患者不同发病时期分离的7株大肠埃希菌,随着抗菌药物的持续使用,全部产生TEM型β-内酰胺酶,其耐药性不断增强。OBJECTIVE To study the antibiotic sensitivities and characterization of β-1acamase activity and the antibiotic resistance mechanisms. METHODS The extended-spectrum β-lactamases were detected. Agar dilution method was used to determine the minimum inhibitory concentration （MIC） of severel antibiotics. The plasmids of clinical isolates were cloned into competent cells （K-12）. RESULTS Isoelectric focusing （IEF）：The last 5 clinical isolates have all got an activity at a high pH 9 which could be presumptively identified as AmpC. The last two clinical isolates had a weak activity with pH of about 8. 0, which belonged to SHV type β-lactamases. All the isolates had a group of activities at the lower pH range of the gel （pH5）. These could be presumptively identified as TEM β-lactamases. CONCLUSIONS The data suggest that each isolate clearly originate from the same population but possess mutations that leads to antibiotic resistance. The combinations of mutations in same isolates suggest that an earlier strain have infected other compartments and become the founder for later antibiotic resistant variants.

关 键 词：Β-内酰胺酶类 等电点聚焦电泳 DNA印迹试验 耐药性 

分 类 号：R378.21[医药卫生—病原生物学]