产AmpC酶肺炎克雷伯菌对氨基糖苷类抗菌药物耐药机制研究  

Resistant mechanisms of AmpC producing Klebsiella pneumoniae to aminoglycosides

作　　者：郑丹[1] 朱健铭 袁求文 吴正海[1] 朱雪萍[1] 

机构地区：[1]台州市黄岩区中医院检验科,浙江台州318020 [2]杭州市余杭区中医院检验科,浙江杭州311106 [3]台州恩泽医疗中心(集团)路桥医院营养科,浙江台州318050

出　　处：《中华医院感染学杂志》2016年第3期488-490,共3页Chinese Journal of Nosocomiology

基　　金：杭州市科技局科技基金资助项目(20110833B48)

摘　　要：目的了解产AmpC酶肺炎克雷伯菌对氨基糖苷类耐药基因、AmpC型β-内酰胺酶基因,整合子遗传标记的存在状况以及菌株的亲缘关系。方法收集医院住院患者痰液标本中分离的肺炎克雷伯菌20株,头孢西丁三维试验均为阳性,采用聚合酶链反应(PCR)法分析7种氨基糖苷类修饰酶、6种16SrRNA甲基化酶、6种AmpC型β-内酰胺酶基因和3种整合子遗传标记,并对检测结果作样本聚类分析。结果 20株产AmpC酶肺炎克雷伯菌均检出氨基糖苷类耐药基因和blaDHA、intⅠ1基因,氨基糖苷类修饰酶基因检出aac(3)-Ⅱ18株、aac(6')-Ⅰb 10株、ant(3″)-Ⅰ5株,检出阳性率分别为90.0%、50.0%、25.0%,16SrRNA甲基化酶检出rmtB2株,检出阳性率为85.0%;样本聚类分析提示,该组菌可分为两个簇群,A簇群中又可分为A1、A2两个亚簇群,A1亚簇群中可分为A1.1(1、5、7、8、10、12、16、20号株)和A1.2(6、15)两个子簇群,均为克隆传播;A2亚簇群中可分为A2.1(2、3、4号株)和A2.2(9、11、13、18、19号株)两个子簇群,亦均为克隆传播,B簇群(14、17号株)亦为克隆传播。结论肺炎克雷伯菌耐药表型与基因型结果相符,携带blaDHA基因导致对AmpC型β-内酰胺类药物耐药,携带aac(3)-Ⅱ、aac(6′)-Ⅰb、ant(3″)-Ⅰ、rmtB基因导致对氨基糖苷类药物耐药,Ⅰ类整合子可能是上述基因的载体,本组菌株存在医院感染的可能。OBJECTIVE To investigate the distribution of aminoglycoside-associated resistant genes,AmpCβ-lactamase genes,genetic markers of integrons,and their relationships in 20 strains of AmpC producing Klebsiella pneumoniae（K.pneumoniae）.METHODS Totally 20 strains of K.pneumoniae were collected from sputum of inpatients in the hospital.And three-dimensional tests of cefoxitin were all positive.Then,7kinds of aminoglycoside modifying enzyme genes,6kinds of 16 SrRNA methyltransferase genes,6kinds of AmpC beta-lactamase genes,and 3kinds of genetic markers of integrons were analyzed by PCR.And the sample cluster analysis was performed on the detection results.RESULTS Aminoglycoside-associated resistant genes,blaDHA,intⅠ1were positive in every strain.And 18strains（90.0%）of aac（3）-Ⅱ,10strains（50.0%）of aac（6＇）-Ⅰb,5strains（25.0%）of ant（3″）-Ⅰ,2strains（10.0%）of rmtB were positive.The sample cluster analysis suggested that strains were divided into cluster A and B.Cluster A was divided into subcluster A1 and A2,and subcluster A1 was divided into A1.1（Strain No.1,5,7,8,10,12,16,20）and A1.2（Strain No.6,15）,both were clonal transmission.Subcluster A2 was divided into A2.1（Strain No.2,3,4）and A2.2（Strain No.9,11,13,18,19）,both were clonal transmission.Cluster B（Strain No.14,17）was also clonal transmission.CONCLUSION Resistant phenotypes of 20 strains of K.pneumoniae were identical with genotypes.BlaDHA leads resistance to AmpCbetalactams;aac（3）-Ⅱ,aac（6′）-Ⅰb,ant（3″）-Ⅰ and rmtBlead resistance to aminoglycosides,class Ⅰ integronns might be carriers of genes above.Nosocomial infections might exist in this group of strains.

关 键 词：肺炎克雷伯菌 AMPC酶 Β-内酰胺酶基因 氨基糖苷类修饰酶基因 样本聚类分析 耐药性 

分 类 号：R378.996[医药卫生—病原生物学]