本研究旨在探讨血流感染碳青霉烯类耐药肺炎克雷伯菌(carbapenem-resistant Klebsiella pneumonia, CRKP)的耐药特点、分子分型特征和菌株同源性，为CRKP感染的临床诊治和预防控制提供理论参考。收集2015年4月至2018年3月期间就诊于上海市某三甲医院患者血标本分离的肺炎克雷伯菌(KP)非重复菌株，采用VITEK 2 Compact全自动细菌鉴定仪鉴定细菌并进行药物敏感性试验，共获得51株CRKP。对CRKP菌株使用纸片扩散法或琼脂稀释法进行15种抗菌药物的敏感性试验；采用聚合酶链式反应(polymerase chain reaction，PCR)检测碳青霉烯酶基因型；通过脉冲场凝胶电泳和多位点序列分型(MLST)技术分析菌株同源性。结果显示，51株CRKP对检测的15种临床常用抗菌药物呈广泛耐药，对其中的哌拉西林、头孢唑啉、头孢吡肟、头孢噻肟、头孢呋辛、头孢他啶、头孢哌酮/舒巴坦、哌拉西林/他唑巴坦和环丙沙星耐药率为100%；对阿米卡星、庆大霉素和复方新诺明的耐药率较高，分别为76.5%、90.2%和62.8%；对替加环素耐药率较低，为3.9%。51株CRKP均检测出blaKPC基因，经测序鉴定为blaKPC-2基因，提示产KPC-2是CRKP对碳青霉烯类耐药的主要机制。MLST检测到4种ST型别，以ST11型为主，共 43株(84.3%)，另有ST15型6株(11.8%)，ST4845型1株及1株新分型。51株CRKP的PFGE图谱相似性系数在62.9%～100%，可分为19个簇(A-S簇)，每簇分别包含1～12个菌株。其中A簇(13.7%)和G簇(23.5%)包含的菌株相对较多，且MLST分型均为ST11型，为优势簇。G簇包含7个型别，G4型为主要克隆菌株。 ST11型为CRKP的主要型别，PFGE分析表明该院存在菌株的克隆传播，应规范抗菌药物使用，同时加强细菌耐药性监测和医院内感染的防控工作。

Drug resistance and molecular typing of carbapenem-resistant Klebsiella pneumonia(CRKP)isolated from a bloodstream infection was conducted to provide scientific basis for clinical practice, prevention, and control measures. Non-repetitive Klebsiella pneumoniae strains collected in a Shanghai tertiary hospital from April 2015 to March 2018 were subjected to the study. A total of 51 strains of CRKP were isolated. Antimicrobial susceptibility testing was carried out, the carbapenemase genes were detected by PCR, and the homology was analyzed by Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). The analysis result showed that the CRKP strains were multi-resistant to antibiotics and bla_KPC-2 gene were detected in all strains. Producing bla_KPC-2 is a major resistant mechanism to carbapenems for Klebsiella pneumoniae. The results of PFGE typing showed there were dominant clones in this hospital, with ST11 being the main type (84.31%). The results indicated that surveillance of bacterial resistance is an effective control for hospital infection management.