South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.
Department of Biomedical Engineering, College of Engineering, The Hong Kong Polytechnic University, Hong Kong, China.
Front Cell Infect Microbiol. 2021 Feb 26;11:633817. doi: 10.3389/fcimb.2021.633817. eCollection 2021.
Carbapenem-resistant (CRAB) is a major cause of nosocomial infections and hospital outbreaks worldwide, remaining a critical clinical concern. Here we characterized and investigated the phylogenetic relationships of 105 CRAB isolates from an intensive care unit from one hospital in China collected over six years. All strains carried , genes for carbapenem resistance, also had high resistance gene, virulence factor, and insertion sequence burdens. Whole-genome sequencing revealed all strains belonged to ST2, the global clone CC2. The phylogenetic analysis based on the core genome showed all isolates were dominated by a single lineage of three clusters and eight different clones. Two clones were popular during the collection time. Using chi-square test to identify the epidemiologically meaningful groupings, we found the significant difference in community structure only existed in strains from separation time. The haplotype and median-joining network analysis revealed genetic differences appeared among clusters and changes occurred overtime in the dominating cluster. Our results highlighted substantial multidrug-resistant CRAB burden in the hospital ICU environment demonstrating potential clone outbreak in the hospital.
耐碳青霉烯肠杆菌 （CRAB）是全球医院感染和爆发的主要原因，仍然是一个关键的临床关注点。在这里，我们对六年来从中国一家医院的重症监护病房收集的 105 株 CRAB 分离株进行了特征描述和系统发育关系研究。所有菌株均携带 、 基因，对碳青霉烯类药物具有耐药性，且携带高耐药基因、毒力因子和插入序列负担。全基因组测序显示所有菌株均属于 ST2，即全球克隆 CC2。基于核心基因组的系统发育分析表明，所有分离株主要由三个聚类和八个不同克隆的单一线粒体组成。两个克隆在采集时间内较为流行。使用卡方检验来确定具有流行病学意义的分组，我们发现仅在分离时间的菌株中存在群落结构的显著差异。单倍型和中位数连接网络分析显示，聚类之间存在遗传差异，且优势聚类随时间发生变化。我们的研究结果强调了医院 ICU 环境中存在大量的多药耐药 CRAB 负担，表明医院内存在潜在的克隆爆发。
