4种β-内酰胺酶基因在一组耐碳青霉烯类肺炎克雷伯菌中的流行分析

Epidemiology of 4β-lactamase genes in carbapenem-resistant Klebsiella pneumoniae strains

目的调查一组耐碳青霉烯类肺炎克雷伯菌(Carbapenem-resistant Klebsiella pneumoniae,CRKP)β-内酰胺酶基因的存在状况。方法收集分离自2016年某医院ICU的20株CRKP菌;采用K-B纸片扩散法进行17种药物敏感性判断,采用聚合酶链反应(PCR)法检测A、B、C、D四类36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(KPC-ISKpn6)。结果 20株CRKP菌每株均检出blaTEM、blaSHV、blaKPC和blaNDM型β-内酰胺酶基因,阳性率分别为100.00%、100.00%、75.00%、100.00%;15株KPC阳性菌株KPC-ISKpn6连锁检测均为阳性。结论 blaTEM、blaSHV、blaKPC、blaNDM等4种基因的菌株在该组CRKP菌中流行;KPC型β-内酰胺酶编码基因由插入序列ISKpn6介导。

OBJECTIVE To investigate the distribution ofβ-lactamase genes in carbapenem-resistant Klebsiella pneumoniae（CRKP）.METHODS A total of 20 strains of CRKP that were isolated from ICUs in 2016 were enrolled in the study,the drug susceptibility testing for 17 types of antibiotics was carried out by using K-B disc diffusion method,totally 36 types ofβ-lactamase genes which belonged to A,B,C and D four categories were detected by means of polymerase-chain-reaction（PCR）,and the detection of type KPCβ-lactamase encoding genes and insertion sequence（KPC-ISKpn6）was performed with the use of PCR.RESULTS The positive rates of blaTEM,blaSHV,blaKPCand blaNDMβ-lactamase genes were respectively 100.00%,100.00%,75.00% and 100.00%in each isolate of the 20 CRKP strains.All of the 15 KPC-positive isolates showed positive for the chain detection of KPC-ISKpn6.CONCLUSIONThe 4 types of genes blaTEM,blaSHV,blaKPCand blaNDM are prevalent among the CRKP strains.The KPC typeβ-lactamase encoding genes are mediated by the insertion sequence ISKpn6.