重症监护病房耐碳青霉烯类肺炎克雷伯菌的耐药基因型及系统进化分析

Analysis of the antimicrobial resistance genotype and phylogenetic evolution of carbapenem-resistant Klebsiella pneumoniae in the intensive care unit

目的通过分析某三甲医院重症监护病房(ICU)的耐碳青霉烯类肺炎克雷伯菌(CRKP)的耐药基因及系统进化关系,为耐药菌防控的管理提供参考依据。方法收集安徽医科大学第二附属医院2018年3―7月ICU住院病人分离的19株CRKP,使用VITEK-2 Compact系统进行细菌鉴定及药敏试验,应用Illumina Hiseq 2500平台进行全基因组测序(WGS),应用MLST软件测定ST型,应用Kaptive软件检测荚膜型,应用Staramr软件筛查菌株的耐药基因,应用Ridom SeqSphere+软件进行cgMLST分型及最小生成树(MST)的构建,并应用CSI Phylogeny 1.4软件及FigTree v1.4.4软件构建最大似然树(MLT),以分析其系统进化关系。结果19株CRKP除了对替加环素敏感,对其他常用抗菌药物均呈现耐药,19株CRKP均携带blaKPC-2耐药基因,均属于ST11-KL64型,MST图中以AY7007、AY7003为中心聚集为一簇,cgMLST分型均为CT1774型,MLT图显示分为四组克隆型,组内亲缘性关系相近。结论该院ICU分离的CRKP以ST11-KL64-CT1774型为主,并具有多重耐药性,存在医院内播散的风险。

Objective To analyze the relationship of resistance genes and phylogenetic evolution of Carbapenem-resistant Klebsiella pneumoniae(CRKP)in the intensive care unit(ICU)of a tertiary hospital,so as to provide a reference for the management of antibiotic resistant bacteria prevention and control.Methods Nineteen strians of CRKP isolateed from ICU inpatients in the Second Affiliated Hospital of Anhui Medical University from March to July 2018 were collected.The VITEK-2 Compact system was used for bacterial identification and drug sensitivity test.The Illumina Hiseq 2500 platform was used for whole genome sequencing(WGS).The MLST soft-ware was used to detect the ST types of strains.The Kaptive software was used to detect the capsular types.The Staramr software was used to screen the antimicrobial resistance genes of the strains.The Ridom SeqSphere+software was used to perform cgMLST typing and construct minimum spanning tree(MST).The CSI Phylogeny 1.4 software and FigTree v1.4.4 software was used to construct a maximum likelihood tree(MLT)to analyze the phylogenetic relationships.Results In addition to being sensitive to tigecycline,nineteen strians of CRKP were resistant to other commonly used antibacterial drugs.The nineteen strians all carried the blaKPC-2 resistance gene and belonged to the ST11-KL64 type.The MST showed that nineteen strians clustered into a cluster with AY7007 and AY7003 as the center.The cgMLST types of the strains were all CT1774 types.The MLT showed that they were assigned into four groups of clono-types,and the genetic relationships within the groups were similar.Conclusions The CRKP isolated from the ICU mainly belongs to ST11-KL64-CT1774 type.The CRKP strains have multidrug resistance,and there is a risk of spreading in the hospital.