检测阴沟肠杆菌产AmpC酶的三种方法比较  

Study on the methods for detecting AmpC β-lactamase produced by Enterobacter cloacae

作　　者：顾怡明[1] 张杰[1] 俞云松[2] 周志慧[2] 杜小玲[3] 

机构地区：[1]首都医科大学附属北京天坛医院,北京100050 [2]浙江大学医学院附属第一医院,浙江杭州310003 [3]首都医科大学附属北京朝阳医院,北京100020

出　　处：《检验医学》2005年第1期42-45,共4页Laboratory Medicine

基　　金：国家自然科学基金资助项目(30270074)

摘　　要：目的　对3种检测阴沟肠杆菌产AmpC酶方法进行评价。方法　对58株第3代头孢菌素或氨曲南 敏感性减低的阴沟肠杆菌采取三维试验法、改良三维试验法、表型筛选法和聚合酶链反应(PCR),并对部分 ampD基因进行克隆测序。结果　三维试验法、改良三维试验法和表型筛选法对58株细菌产AmpC酶的检出率 分别为70.69%、65.52%和86.21%。PCR扩增显示ampD基因的阳性率84.48%(49/58),对11株耐药菌株的 PCR扩增产物进行克隆测序,其中8株去阻遏高产突变株均存在羧基端可疑的突变位点。结论　表型筛选法是 一种结果可靠、操作快速简便、适于微生物实验室常规开展的检测阴沟肠杆菌产AmpC酶的方法。Objective To evaluate three methods for detecting AmpC β-lactamase produced by Enterobacter cloacae. Methods Three-dimensional test, improved three-dimensional test and phenotype screening test were performed to detect the 58 strains of Enterobacter cloacae with decreased susceptibilities to the third-generation cephalosporins or aztreonam. The ampD genes from 11 isolates were sequenced. Results From the 58 strains of Enterobacter cloacae, the derepressed AmpC β-lactamase-producers were 70.69% by three-dimensional test, 65.52% by improved three-dimensional test and 86.21% by phenotype screening test respectively. The ampD gene sequencing results of 8 strains which stably producing derepressed AmpC β-lactamase showed that there were amino acid substitutions in the carboxy-terminal of AmpD. Conclusions Phenotype screening test is reliable to detect AmpC β-lactamase and easy to use in department of microbiology.

关 键 词：阴沟肠杆菌 三维试验 AMPC酶 表型 基因 氨曲南 筛选法 克隆测序 阻遏 PCR扩增 

分 类 号：R978[医药卫生—药品] R378[医药卫生—药学]