Han Yu-Ling, Wang Hua, Zhu Hong-Zhe, Lv Ying-Ying, Zhao Wen, Wang Yan-Yan, Wen Jian-Xun, Hu Zhi-De, Wang Jun-Rui, Zheng Wen-Qi
Department of Laboratory Medicine, The Affiliated Hospital of Inner Mongolia Medical University, Hohhot, China.
Department of Parasitology, The Basic Medical College of Inner Mongolia Medical University, Hohhot, China.
mSystems. 2024 Dec 17;9(12):e0110124. doi: 10.1128/msystems.01101-24. Epub 2024 Nov 18.
Carbapenem-resistant hypervirulent (CR-hvKP) strains present a significant global public health threat due to their high mortality rates. This study investigated the genomic characteristics of seven ST11-K1 CR-hvKP isolates harboring highly homologous KPC-2-encoding multidrug-resistance plasmids. The strains were isolated from a Chinese tertiary hospital between 2017 and 2020. Whole-genome sequencing and bioinformatic analysis revealed various antibiotic resistance genes (ARGs) and virulence determinants. The -bearing plasmids that contain multiple antibiotic-resistance genes were also identified in these strains. ISfinder and Orifinder were applied to identify insertion sequences (IS) and conjugation-related factors among these -bearing plasmids. The was highly consistent in seven -bearing plasmids (IS-IS-IS-IS). In addition, we found a region composed of IS, Tn, and IS. It was located upstream of the gene and presented in six -bearing plasmids, with pCR-hvKP221-KPC-P3 as an exception. Conjugation experiments demonstrated the horizontal transfer of resistance plasmids pCR-hvKP128-KPC-P1 and pCR-hvKP132-KPC-P1 across species. Notably, pLVPK-like virulence plasmids carrying virulence gene clusters pCR-hvKP173-Vir-P1, and pCR-hvKP221-Vir-P1 were also detected. A fusional plasmid pCR-hvKP221-Vir-P2, which carries virulence gene clusters and ARGs, was also identified. Five CR-hvKP strains displayed enhanced biofilm formation and high virulence infection models. Phylogenetic and single nucleotide polymorphism (SNP) analyses indicated a close genetic relationship among the isolates, suggesting a subclade. These findings highlight the complex genetic profiles and potential transmission mechanisms of CR-hvKP strains.
We reported seven CR-hvKP strains all carried a highly homologous integrated IncFⅡ-resistant plasmid, and two strains harbored virulence plasmids. Conjugation experiments confirmed the transferability of these plasmids, indicating a potential for resistance spread. Phylogenetic analysis clarified the relationship among the CR-hvKP isolates. This study provides insights into the phenotypic and genomic characteristics of seven ST11-K1 CR-hvKP strains. The high prevalence and potential for local outbreaks emphasize the need for effective control measures.
耐碳青霉烯类高毒力（CR-hvKP）菌株因其高死亡率对全球公共卫生构成重大威胁。本研究调查了7株携带高度同源KPC-2编码多药耐药质粒的ST11-K1 CR-hvKP分离株的基因组特征。这些菌株于2017年至2020年期间从一家中国三级医院分离得到。全基因组测序和生物信息学分析揭示了各种抗生素抗性基因（ARG）和毒力决定因素。在这些菌株中还鉴定出了携带多个抗生素抗性基因的质粒。应用ISfinder和Orifinder来鉴定这些携带质粒中的插入序列（IS）和接合相关因子。在7个携带质粒中高度一致（IS-IS-IS-IS）。此外，我们发现了一个由IS、Tn和IS组成的区域。它位于基因上游，在6个携带质粒中存在，pCR-hvKP221-KPC-P3除外。接合实验证明了抗性质粒pCR-hvKP128-KPC-P1和pCR-hvKP132-KPC-P1跨物种的水平转移。值得注意的是，还检测到携带毒力基因簇pCR-hvKP173-Vir-P1和pCR-hvKP221-Vir-P1的pLVPK样毒力质粒。还鉴定出了携带毒力基因簇和ARG的融合质粒pCR-hvKP221-Vir-P2。5株CR-hvKP菌株在感染模型中表现出增强的生物膜形成和高毒力。系统发育和单核苷酸多态性（SNP）分析表明分离株之间存在密切的遗传关系，提示为一个亚分支。这些发现突出了CR-hvKP菌株复杂的遗传图谱和潜在的传播机制。
我们报告了7株CR-hvKP菌株均携带高度同源的整合IncFⅡ抗性质粒，且有2株携带毒力质粒。接合实验证实了这些质粒的可转移性，表明存在抗性传播的可能性。系统发育分析阐明了CR-hvKP分离株之间的关系。本研究提供了对7株ST11-K1 CR-hvKP菌株表型和基因组特征的见解。高流行率和局部暴发的可能性强调了采取有效控制措施的必要性。
