肺炎克雷伯菌临床分离株β-内酰胺类耐药特征分析

characterization of resistance to β-lactams in clinical isolates of klebsiella pneumoniae

目的 调查一组耐药肺炎克雷伯菌的β-内酰胺类药物耐药的遗传学背景和可移动遗传元件的存在情况,以及二者可能存在的关系.方法 收集2008年8月-2010年5月浙江省杭州市和湖州市6家医院共47株肺炎克雷伯菌,先采用改良hodge试验检测产碳青霉烯酶表型确证试验,再采用聚合酶链反应(pcr)的方法检测a～d四类40种β-内酰胺酶基因与膜孔蛋白编码基因(ompk35、omp k36)和12种可移动遗传元件标记基因,最后对检测结果作指标聚类分析.结果 本组耐药肺炎克雷伯菌共检出改良hodge试验阳性株35株,5种β-内酰胺酶基因,并发现kpc-2变异型( kpc-2-1ike,genbank登录号:hq258934),以及9种可移动遗传元件标记基因.耐药肺炎克雷伯菌的ompk35、ompk36膜孔蛋白编码基因经测序并与肺炎克雷伯菌敏感株比对均存在突变.指标聚类分析显示,kpc-2以及变异型与 iskpn6高度相关联,tem-1与isecpl、is26、inti1、trbc、is903相关联,cmy-2、oxa-30、dha-1与tnpu、tnp513、trbc相关联.结论 携带5种β-内酰胺酶基因和ompk35、ompk36膜孔蛋白编码基因存在突变是本组肺炎克雷伯菌对β-内酰胺类药物耐药的主要原因. abstract： objective to investigate correlation between drug-resistance related genes and mobile genetic elements of klebsiella pneumoniae resistant to β-lactams. methods forty-seven strains of multidrug-resistant klebsiella pneumoniae were collected from 6 hospitals in hangzhou and huzhou of zhejiang province from august 2008 to may 2010.modified hodge test was performed to detect phenotypes of carbapenemases.forty kinds of β-lactamases (class a-d),ompk35,ompk36,and 12 kinds of mobile genetic elements were detected by pcr,and the results were analyzed by index cluster.results thirty-five strains were positive in modified hodge test,and 5 kinds of β-lactamases gene ( including kpc-2-like,genbank:hq258934) and 9 kinds of mobile genetic elements were detected.mutations were observed in ompk35 and ompk36 when compared with sensitive strains.index cluster analysis showed that correlation existed between kpc-2,kpc-2-like and iskpn6,between tem-1 and isecpl,is26,int Ⅰ 1,trbc,is903,and between cmy-2,oxa-30,dha-1 and tnpu,tnp513,trbc.conclusions five kinds of β-1actamases genes,and mutations in ompk35 and ompk36 may be associated with the resistance to β-1actams in multidrug-resistant klebsiella pneumoniae.

Objective To investigate correlation between drug-resistance related genes and mobile genetic elements of Klebsiella pneumoniae resistant to β-lactams. Methods Forty-seven strains of multidrug-resistant Klebsiella pneumoniae were collected from 6 hospitals in Hangzhou and Huzhou of Zhejiang province from August 2008 to May 2010.Modified Hodge test was performed to detect phenotypes of carbapenemases.Forty kinds of β-lactamases (class A-D),ompK35,ompK36,and 12 kinds of mobile genetic elements were detected by PCR,and the results were analyzed by index cluster.Results Thirty-five strains were positive in modified Hodge test,and 5 kinds of β-lactamases gene ( including KPC-2-like,GenBank:HQ258934) and 9 kinds of mobile genetic elements were detected.Mutations were observed in ompK35 and ompK36 when compared with sensitive strains.Index cluster analysis showed that correlation existed between KPC-2,KPC-2-like and ISKpn6,between TEM-1 and ISEcpl,IS26,int Ⅰ 1,trbC,IS903,and between CMY-2,OXA-30,DHA-1 and tnpU,tnp513,trbC.Conclusions Five kinds of β-1actamases genes,and mutations in ompK35 and ompK36 may be associated with the resistance to β-1actams in multidrug-resistant Klebsiella pneumoniae.