Department of Clinical Laboratory, The First People's Hospital of Neijiang, Neijiang, Sichuan, China.
The School of Basic Medical Sciences, Southwest Medical University, Luzhou, Sichuan, China.
Sci Rep. 2024 Oct 16;14(1):24296. doi: 10.1038/s41598-024-74307-6.
Klebsiella pneumoniae is among the most important Gram-negative pathogens that can cause serious nosocomial infections. The emergence and prevalence of hypervirulent carbapenem-resistant K. pneumoniae (Hv-CRKP) pose a significant challenge to public health. In this study, we characterized thirty carbapenem-resistant K. pneumoniae (CRKP) strains from a tertiary care hospital in Sichuan province, China, by whole-genome sequencing and genome analysis. These strains were all highly resistant to carbapenem but remained susceptible to tigecycline. Of the 30 tested CRKP strains, 23 were positive for bla and seven for bla. These bla-positive strains all belonged to ST11, while bla-positive strains belonged to five distinct STs. Phylogenetic analysis revealed a predominant intra-hospital transmission of ST11-KL64 in KPC-2-producing CRKP, and that both clonal and horizontal transmission of bla have occurred among NDM-5-producing CRKP strains in this hospital. Hypervirulence genes were commonly detected in the CRKP. The prevalent pLVKP-like plasmid and ICEKp seem to have contributed largely to the transmission of virulence genes in them. bla was located on highly similar IncX3 plasmids in the collected strains, and its truncated vision was highlighted. bla was primarily carried by IncFII/IncR plasmids in our collection. At least two IncFII/IncR plasmid subtypes were identified, exhibiting high similarity to many previously reported bla-bearing plasmids from different parts of China. The findings provide an expanded knowledge of the genetic characteristics of CRKP, the transmission pattern of carbapenem-resistance genes, and also the convergence of Hv-CRKP.
肺炎克雷伯菌是最重要的革兰氏阴性病原体之一，可导致严重的医院获得性感染。高毒力碳青霉烯类耐药肺炎克雷伯菌（Hv-CRKP）的出现和流行对公共卫生构成了重大挑战。在这项研究中，我们通过全基因组测序和基因组分析，对来自中国四川省一家三级医院的 30 株碳青霉烯类耐药肺炎克雷伯菌（CRKP）进行了特征描述。这些菌株对碳青霉烯类均高度耐药，但对替加环素仍保持敏感。在 30 株检测的 CRKP 菌株中，bla 和 bla 均为阳性。这些 bla 阳性菌株均属于 ST11，而 bla 阳性菌株则属于五个不同的 ST。系统发育分析显示，在产 KPC-2 的 CRKP 中，ST11-KL64 主要在院内传播，而在产 NDM-5 的 CRKP 菌株中，bla 既发生了克隆传播，也发生了水平传播。CRKP 中普遍检测到毒力基因。流行的 pLVKP 样质粒和 ICEKp 似乎在它们的毒力基因传播中起了很大作用。bla 位于收集菌株中高度相似的 IncX3 质粒上，并突出显示其截断的视野。bla 主要由我们收集的 IncFII/IncR 质粒携带。至少鉴定出两种 IncFII/IncR 质粒亚型，与来自中国不同地区的许多先前报道的携带 bla 的质粒高度相似。这些发现提供了对 CRKP 的遗传特征、碳青霉烯类耐药基因的传播模式以及 Hv-CRKP 的趋同的更广泛了解。
