摘要目的：调查分析由肺炎克雷伯菌引起的血流感染患者的临床特征及肺炎克雷伯菌的分子特征,比较经典与高毒力肺炎克雷伯菌的区别。方法根据患者临床病例资料及微生物实验室信息资料,回顾性分析北京朝阳医院2008至2012年70例由肺炎克雷伯菌引起的菌血症患者的临床特征,同时对分离的70株肺炎克雷伯菌进行研究。采用PCR检测肺炎克雷伯菌的毒力基因及耐药基因、分别采用多位点序列分析（ MLST)方法以及脉冲场凝胶电泳（ PFGE)方法进行细菌同源性分析。使用SPSS 17．0统计软件包进行数据分析。分类数据不同组间比较采用χ2检验,使用Whonet5．6,统计分析细菌对抗菌药物的敏感性。结果31．4%（22/70)的肺炎克雷伯菌菌血症是由高毒力的肺炎克雷伯菌引起,主要的血清型是K1、K2、K20和K57。40．9%（9/22)的高毒力株感染的患者没有基础疾病,95．8%（46/48)的经典肺炎克雷伯菌感染的患者存在一种或多种基础疾病。95．5%（21/22)高毒力株的肺炎克雷伯菌是社区获得性感染,35．4%（17/48)经典的肺炎克雷伯菌是社区获得性感染,χ2＝21．912,P<0．001。共发现2株产超广谱β内酰胺酶（ ESBLs)的高毒力株肺炎克雷伯菌。高毒力的肺炎克雷伯菌共有14个PFGE型,其中6例原发肝脓肿患者的分离株具有相同的PFGE型。结论在免疫力正常患者的社区获得性感染中出现高毒力肺炎克雷伯菌的严重感染,并检出2株产ESBLs的高毒力肺炎克雷伯菌,其耐药性有上升趋势,需要临床更加重视。（中华检验医学杂志,2015,38：627-631)

abstractsObjective To investigate the clinical features and molecular characteristics of bacteremia caused by K. pneumoniae and study on the differences between classical and hypervirulent K. pneumonia( hvKP) . Methods The clinical features of 70 cases of K. pneumoniae bacteremia collected from Beijing Chaoyang Hospital from 2008 to 2012 were retrospectively analyzed. The patients were identified according to the records from the Clinical Microbiology Department. Patients′ data were obtained from medical records. The molecular characteristics of the K. pneumoniae strains were also studied using PCR, multilocus sequence typing and pulsed field gel electrophoresis( PFGE) methods. Data were analyzed using the statistical package SPSS for windows version 17. 0. For categorical data, different groups were compared using the Chi-square test to analyze the quantitative variables. P≤0. 05 was considered to be statistically significant. All susceptibility data were analyzed using Whonet, version 5. 6. Results The hvKP was identified from 31. 4% of the patients with K. pneumoniae bacteremia, which displayed 4 serotypes ( K1, K2, K20, and K57). About 40. 9% (9/22) hypervirulent strains were isolated from patients without underlying diseases, while 95. 8% (46/48) of the classic K. pneumoniae infections were found in patients with the presence of one or more underlying diseases. More hvKP positive patients (95. 5%, 21/22) had community-acquired infections compared with classical K. pneumonia (cKP) infected patients (35. 4%, 17/48). There was a significant difference between these two groups (χ2 =21. 912,P <0. 001). Two ESBLs-producing hvKP strains were found. The 22 hvKP isolates had 14 different PFGE patterns, among which 6 isolates ( patients with primary liver abscess) shared similar PFGE patterns. Conclusions The <br> emerging hvKP was prevalent in patients with severe community-acquired infections in healthy individuals. Two ESBLs-producing hvKP strains were identified. Drug resistance had a rising trend, which called for more attention in clinical settings.