植生克雷伯菌与肺炎克雷伯菌β-内酰胺酶编码基因研究

β-lactamase resistance genes in multi-drug resistant Klebsiella planticolaand Klebsiella pneumonia

目的调查一组耐药克雷伯菌属β-内酰胺酶编码基因表达状况以及KPC型β-内酰胺酶编码基因与插入序列的关系,为临床治疗提供参考依据。方法收集医院2009年10月-2011年3月分离出的20株克雷伯菌属,采用K-B纸片扩散法进行抗菌药物敏感性判断;采用聚合酶链反应(PCR)法检测A、B、C、D等4类40种β-内酰胺酶基因,PCR法连锁检测KPC型β-内酰胺酶编码基因与插入序列,采用Chromas软件对PCR阳性产物测序结果进行读序,并对测序结果用Chromas直接作BLAST Search比对。结果 20株克雷伯菌属共检出5种A类β-内酰胺酶编码基因TEM、SHV、CTX-M-1群、LAP、KPC,1种C类β-内酰胺酶编码基因DHA,1种D类β-内酰胺酶编码基因OXA-1群,阳性检出率依次为SHV100.0%、TEM8 5.0%、DHA85.0%、CTX-M-1群55.0%、KPC45.0%、LAP10.0%和OXA-1群5%;9株KPC阳性菌株KPC-ISKpn6连锁检测均为阳性。结论产β-内酰胺酶是克雷伯菌属耐β-内酰胺类药物的重要成因之一,KPC型β-内酰胺酶编码基因由插入序列ISKpn6介导。

OBJECTIVE To investigate the expression of β-lactamase genes in resistant K lebsiella genera and the correlation between β-lactamase resistance genes and insertion sequences in multi drug-resistant K lebsiella ,so as to provide reference to clinic .METHODS A total of 20 strains of K lebsiella isolated from Oct .2009 to Mar .2011 were collected .Drug sensitivity was determined by K-B tests .All 40 kinds of β-lactamases（class A-D） and KPC-ISKpn6 were detected by PCR .Chromas software was used for ordering the results of positive production from PCR and using BLAST Search to compare them .RESULTS In 20 strains of K lebsiella ,5 kinds of class A β-lactam-resistancegenes（TEM,SHV,CTX-M-1-like,LAP,KPC）,1kindofclassB β-lactam-resistancegene （DHA） ,1 kind of class D β-lactam-resistance gene （OXA-1-like） were detected .The positive rates were SHV 100 .0% ,TEM 85 .0% ,DHA 85 .0% ,CTX-M-1-like 55 .0% ,KPC 45 .0% ,LAP 10 .0% and OXA-1-like 5 .0% .The 9 strains of positive K PC ,K PC-ISK pn6 ,were tested positive in chain detection .CONCLUSION In this group of K lebsiella ,β-lactam-resistance genes was the main cause of β-lactam resistance . K PC gene was mediated by insertion sequences（ISK pn6） .