K1、K2型肺炎克雷伯菌临床特征及同源性分析

Clinical features and homologous analysis of K1 and K2 serotypes of Klebsiella pneumoniae

目的研究荚膜多糖分型K1、K2型肺炎克雷伯菌的临床资料,分析临床特征及分子特点。方法收集血流感染肺炎克雷伯菌,检测荚膜血清型、毒力基因rmp A,拉丝试验确定黏液表型(MH)。采用脉冲场凝胶电泳(PFGE)和多位点序列分析(MLST)进行细菌同源性分析。结果 181株肺炎克雷伯菌菌株中共检出K1型17株,检出率为9. 4%,检出K2型20株,检出率为11. 0%,rmp A检出率为89. 2%(33/37),拉丝试验阳性率为64. 9%(24/37),59. 5%(22/37)为MH+rmp A+。70. 3%为社区获得性感染,67. 6%以肝胆系统疾病为主,29. 7%致脓毒性休克,2. 7%(1/37)转移引起眼内炎并且导致失明。K1型中88. 2%(15/17)为ST23,K2型中50. 0%(10/20)为ST65。共分为9个PFGE群,K1型中76. 5%(13/17)为同一PFGE群,均为ST23; K2型中45. 0%(9/20)为同一PFGE群,均为ST65。结论 K1、K2血清型以MH+rmp A+常见,常合并一种或多种疾病转归良好。K1型中主要为ST23,K2型中主要为ST65,K1和K2之间没有相同ST分型和PFGE分型,但在本地区存在一定的流行克隆株,需要引起临床重视。

Objective To evaluate clinical data of capsular serotypes K1 and K2 of Klebsiella pneumoniae,so as to analyze their clinical and molecular characteristics. Methods Bloodstream infected Klebsiella pneumoniae was collected to detect serotypes and virulence gene rmp A,and mucous phenotype（MH） was determined by string test. Furthermore,the homology among bacterial strains was analyzed by pulsed-field gel electrophoresis（PFGE） and multilocus sequence typing（MLST）.Results K1 type was detected in 17 out of 181 strains of Klebsiella pneumonia,with the detection rate of 9. 4%,and K2 type was detected in 20 strains,with the detection rate of 11. 0%. The detection rate of rmp A was 89. 2%（33/37）,besides,the positive rate of string test was 64. 9%（24/37）,and 59. 5%（22/37） was MH＋rmp A＋. Meanwhile,70. 3% were community-acquired infections,67. 6% were predominated by hepatobiliary system diseases,29. 7% were with induced septic shock,and2. 7%（1/37） were endophthalmitis that resulted in blindness due to metastasis. In K1 serotype isolate,88. 2%（15/17） were ST23,and 50. 0%（10/20） were ST65 in K2 serotype. In addition,there were a total of 9 PFGE clusters,and 76. 5%（13/17）in the K1 serotype had the same PFGE cluster,all of which were ST23; besides,45. 0%（9/20） in K2 serotype possessed the same PFGE cluster,all of which were ST65. Conclusion K1 and K2 serotypes,with MH＋rmp A＋as the commongenotype,are frequently combined with one or more diseases,and satisfied prognostic outcomes. K1 and K2 serotypes are dominated by ST23 and ST65,respectively. Although there is no similar sequence typing and PFGE typing between K1 and K2,there are some popular clone strains in this area,which deserve clinical attention.