携带wcaG毒力基因ST19产酸克雷伯菌致白血病患者死亡的分析

摘要

We investigated the cause of a leukemia patient induced by infect in a strain of Klebsiella oxytoca with hypermucoviscosity (HMV) phenotype.Identification and drug susceptibility of the isolate were carried out with VITEK-2 compact system.HMV phenotype was detected by string-test.The major high virulence capsular serotypes (K1,K2,K5,K20,K54 and K57) and virulence factors (rmpA,wcaG,allS,kfu,aerobactin,fimH,uge,wabG and cf29a) were detected by polymerase chain reaction and DNA sequencing.Molecular typing was performed by multilocus sequence typing (MLST).Results showed that the isolates of blood and lung tissue were Klebsiella oxytoca belonged to ST 19,which were sensitive to the antibiotics used in test,expressing the HMV phenotype.The virulence gene wcaG was found,while other virulence genes and the major high virulence capsular serotypes were negative.It indicates that ST19 Klebsiella oxytoca with wcaG virulence gene is the main reason causing leukemic patient death.%目的 了解1例高黏液表型(HMV)产酸克雷伯菌致白血病患者的死亡原因.方法 采用Vitek 2 Compact全自动微生物仪进行菌株鉴定及药敏试验,黏液丝试验检测HMV表型,PCR方法及基因测序检测主要的高毒力荚膜血清型基因(K1、K2、K5、K20、K54、K57)和毒力基因(rmpA、wcaG、allS、kfu、aerobactin、mrkD、fimH、uge、wabG、cf29a),多位点序列分析(MLST)对该菌株进行分子分型.结果 白血病患者血液及肺组织分离株均为产酸克雷伯菌,MLST分型为同一型ST19,该菌株对所测药物均敏感,具有高黏液表型,只检测到wcaG毒力基因,其他毒力基因和所测荚膜血清型基因均阴性.结论 携带wcaG毒力基因是ST19产酸克雷伯菌致白血病患者死亡的主要原因,应引起临床关注.