Department of Microbiology, Chinese PLA General Hospital, Beijing, China.
Clin Microbiol Infect. 2014 Nov;20(11):O818-24. doi: 10.1111/1469-0691.12664. Epub 2014 Jun 14.
The molecular epidemiology and prevalence of virulence factors of isolates from patients with Klebsiella pneumoniae liver abscess (KLA) in mainland China are unknown. Klebsiella pneumoniae isolates were obtained from drainage samples aseptically collected from patients with pyogenic liver abscess (PLA). The genetic similarity of KLA isolates was analyzed by pulsed-field gel electrophoresis. The hypermucoviscosity (HV) phenotype was identified by a positive string test. The K1 and K2 genotypes, the pLVPK-derived genetic loci, aerobactin gene, kfu and alls were detected by PCR amplification. The sequence types (STs) were identified by multilocus sequence typing. Among the 51 non-repetitive KLA isolates, 49 PFGE types have been identified. In total, 19 (37.2%) and 14 (27.4%) of the 51 KLA isolates belonged to clonal complex (CC) 23 and CC65, respectively, while the other 18 isolates (35.3%) were defined as other STs. CC23 consisted of only K1 strains, while CC65 included only K2 strains. All non-K1/K2 strains were classified as STs other than CC23 and CC65. Approximately 70.6% (36/51) of KLA isolates exhibited an HV phenotype. Both K1 and K2 isolates presented significantly higher prevalence of the pLVPK-derived loci than non-K1/K2 isolates. The K1 isolates had a significantly higher prevalence of the kfu and allS genes than K2 and non-K1/K2 isolates, while the K2 isolates exhibited higher repA prevalence than K1 and non-K1/K2 isolates. The majority of KLA isolates belonged to CC23K1 and CC65K2, while other STs with non-K1/K2 capsular types have also been identified. The virulent factors exhibited diverse distribution among the different clones of KLA isolates.
中国大陆地区肺炎克雷伯菌肝脓肿（KLA）患者分离株的分子流行病学和毒力因子流行情况尚不清楚。无菌采集化脓性肝脓肿（PLA）患者的引流样本，获得肺炎克雷伯菌分离株。通过脉冲场凝胶电泳分析 KLA 分离株的遗传相似性。通过阳性拉丝试验鉴定高黏液表型（HV）。通过 PCR 扩增检测 K1 和 K2 基因型、pLVPK 衍生遗传基因座、aerobactin 基因、kfu 和 alls。通过多位点序列分型鉴定序列类型（ST）。在 51 个非重复的 KLA 分离株中，已鉴定出 49 种脉冲场凝胶电泳型。总的来说，51 个 KLA 分离株中，19 个（37.2%）和 14 个（27.4%）分别属于克隆群（CC）23 和 CC65，而其余 18 个（35.3%）被定义为其他 ST。CC23 仅由 K1 株组成，而 CC65 仅由 K2 株组成。所有非 K1/K2 株均被归类为 CC23 和 CC65 以外的 ST。大约 70.6%（36/51）的 KLA 分离株表现出 HV 表型。K1 和 K2 分离株的 pLVPK 衍生基因座的流行率明显高于非 K1/K2 分离株。K1 分离株的 kfu 和 allS 基因的流行率明显高于 K2 和非 K1/K2 分离株，而 K2 分离株的 repA 流行率高于 K1 和非 K1/K2 分离株。大多数 KLA 分离株属于 CC23K1 和 CC65K2，而其他 ST 也鉴定出具有非 K1/K2 荚膜型的分离株。不同 KLA 分离株克隆的毒力因子分布不同。
