产AmpC酶肺炎克雷伯菌对氨基糖苷类抗生素的耐药性分析  

Aminoglycoside resistance of AmpC-producing Klebsiella pneumoniae

作　　者：邓敏 谢新生 徐水凌[2] 漆秋兰[2] 张戡 吴建明 陆许贞 王旭 

机构地区：[1]嘉兴医学院附属第一医院感染科,浙江嘉兴314000 [2]嘉兴医学院微生物教研室,浙江嘉兴314000

出　　处：《中国微生态学杂志》2016年第1期25-28,共4页Chinese Journal of Microecology

基　　金：嘉兴市科技局科研项目(2013AY21042-2);嘉兴市医学重点学科感染性疾病学(04-Z-15)

摘　　要：目的了解本地区质粒介导的耐药机制在产AmpC酶肺炎克雷伯菌多重耐药中的作用、氨基糖苷修饰酶(AMEs)基因类型及转移方式。方法头孢西丁三维试验方法,检测产AmpC酶菌株;采用接合转移试验了解肺炎克雷伯菌耐药基因转移方式。采用K-B纸片测定产AmpC接合子对4种氨基糖苷类抗生素的敏感性,并采用PCR技术检测AMEs基因。结果临床分离的820株肺炎克雷伯菌共筛选出108株疑产AmpC酶菌株,阳性率为13.17%。经接合转移试验、AmpC酶表型确认试验共获得53株产AmpC接合子。其中67.9%的接合子(36/53)检出氨基糖苷修饰酶基因,aac(3)-I和aac(6′)-II未检出,对4种常用氨基糖苷类抗生素(阿米卡星、庆大霉素、妥布霉素、奈替米星)耐药率分别为37.7%、68.0%、43.4%和62.3%。结论本地区质粒介导AmpC酶是肺炎克雷伯菌产生多重耐药的重要原因,产酶株对氨基糖苷类高度耐药,其耐药性与AMEs密切相关,耐药基因质粒的转移可导致耐药性的传播扩散。Objective To explore the mechanism of plasmid-medicated resistance of AmpC enzyme-producing Klebsiella pneumoniae to aminoglycosides and the genotypes of aminoglycoside modifying enzymes（AMEs）.Methods Cefoxitin three-dimensional extract test was performed to detect the AmpC-producing strains;Disk diffusion method was used to determine their susceptibility to 4aminoglycoside antibiotics.The transfer of drug-resistant gene was identified by conjugal transfer test.The genotypes of AMEs were determined by PCR.Results Of the 820 isolates,the rate of AmpC B-lactamase was 13.17%（108/720）.Conjugal transfer and genotyping tests identified 53AmpC-producing strains,36（67.9%）of which were found carrying AMEs gene,but aac（3）-I and aac（6′）-II genes were not found.The resistance rates of these AmpC-producing strains to Amikacin,Gentamicin,Tobramycin and Netilmicin were 37.7%,68.0%,43.4% and 62.3%,respectively.Conclusion Plasmid-mediated AmpC enzyme is an important mechanism of the multi-drug resistance in K.pneumoniae.AmpC-producing strains are highly resistant to aminoglycosides,which is closely related to AMEs.The resistance can be transferred through bacterial conjugation.

关 键 词：肺炎克雷伯菌 抗药性 多药 AMPC 超广谱Β-内酰胺酶 质粒 

分 类 号：R446.65[医药卫生—诊断学]