郑州市某三甲医院耐碳青霉烯类抗生素肺炎克雷伯菌的基因组分型分析

Genomic subtyping of nosocomial transmission of carbapenem resistant Klebsiella pneumoniae

目的分析郑州市某三甲医院耐碳青霉烯类抗生素肺炎克雷伯菌(CRKP)的基因组分型特征。方法于2019年12月4日至2020年1月10日,自郑州市某三甲教学医院各临床科室送检且开展微生物检测的标本中分离出67株CRKP菌株。通过将全基因组测序和序列分析,确定多位点序列分型(MLST)型别(ST)和碳青霉烯类抗生素耐药基因。基于全基因组SNP构建进化树将67株CRKP划分克隆群,并且分析各克隆群的分离病房和分离日期。结果67株CRKP分为4种ST型,其中64株为ST11型。ST11型菌株中有62株携带blaKPC-2基因。基于全基因组水平的SNP构建进化树,将64株ST11型菌株分为4个克隆群,其中2个克隆群为优势克隆群,分别包含33株和27株菌;另外2个克隆群分别只包含2株菌。优势克隆群在分离病区和分离日期上均没有聚集性。结论携带blaKPC-2基因的ST11型菌株已分化出多个克隆群,且可在同一家医院存在多个克隆群菌株的平行、独立流行。

Objective To analyze the genomic epidemiological subtyping of carbapenem resistant Klebsiella pneumoniae(CRKP)isolated from a Third-class A hospital in Zhengzhou.Methods From December 4,2019 to January 10,2020,67 strains of CRKP were isolated from the samples submitted by the clinical departments of a Third-class A teaching hospital in Zhengzhou for microbiological testing.Multi-locus sequence typing(MLST)and carbapenem resistance genes were identified by whole genome sequencing and sequence analysis.Based on the whole genome SNP,the phylogenetic tree was constructed,and 67 CRKP strains were divided into clonal groups.The isolation ward and date of each clone group were analyzed.Results Sixty-seven CRKP strains were classified into four MLST types(STs),of which 64 were ST11.There were 62 ST11 strains carrying blaKPC-2 gene.Based on genome-wide SNP phylogenetic tree,64 ST11 strains were divided into four clone groups,two of which were dominant clone groups,including 33 and 27 strains respectively;the other two clone groups only contained 2 strains respectively.There was no aggregation of the dominant clones in the isolation department and date.Conclusion Multiple clonal groups of ST11 strain carrying blaKPC-2 gene are differentiated during spreading,and they can spread in parallel and independently in the same hospital.