产ESBLs大肠埃希菌氨基糖苷类修饰酶基因的研究

Genotyping of Aminoglycoside-modifying Enzymes in ESBLs-producing Escherichia coli

目的了解产ESBLs大肠埃希菌氨基糖苷类修饰酶基因存在状况。方法对20株大肠埃希菌,采用聚合酶链反应（PCR）法检测aac（3）-Ⅱ、aac（6）′-Ⅰb、ant（3）″-Ⅰ、ant（2）″-Ⅰ等4种氨基糖苷类修饰酶基因。结果20株大肠埃希菌呈现多重耐药,对氨基糖苷类抗生素的耐药率在60%-90%之间,氨基糖苷类修饰酶基因aac（3）-Ⅱ、aac（6）′-Ⅰb、ant（3）″-Ⅰ、ant（2）″-Ⅰ基因阳性率分别为30%、35%、25%和5%。携带1种或1种以上基因的菌株有14株（70%）。结论临床分离的大肠埃希菌多重耐药严重,氨基糖苷类修饰酶基因携带率较高。

Objective To investigate the drug resistance and genotyping of aminoglycoside -modifying enzymes （AMEs） in ESBLs- producing Escherichia coll. Methods Microdilution tests were performed to detect susceptibility of 21 kinds of antimicrobial agents in 20 strains of Escherichia coli. Genotypes of AMEs were detected by polymerase chain reaction （PCR） . Results Twenty strains were all multidrug- resistant. The resistance rates to aminoglycosides ranged from 60% to 90%. The positive rates of AM E genes of aac（ 3）- Ⅱ ,aac （6′）- Ⅰ b, ant（3″）- Ⅰ , ant （2″）- Ⅰ were 30%, 35%, 25% and 5 %, respectively. There were 14 strains （70%） carrying one or more genes. Conclusion The multidrug resistance of Escherichia coli isolated from clinical specimens is serious, and there are higher positive percentages of genotyping of aminoglycoside - modifying enzymes in E. Coli.