Department of Clinical Laboratory Medicine, Taizhou Municipal Hospital, Taizhou, China.
State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
Front Cell Infect Microbiol. 2023 Mar 23;13:1131059. doi: 10.3389/fcimb.2023.1131059. eCollection 2023.
The objective of this study is to thoroughly analyze the detailed genomic characteristics of clinical strain 211703 of , which co-carrying and genes. 211703 was isolated from the patient's cerebrospinal fluid drainage sample in a Chinese tertiary hospital.
Carbapenemase NDM was detected by the immunocolloidal gold technique. The MIC values were determined by VITEK2. The whole genome sequence of 211703 was analyzed using phylogenetics, genomic comparison, and extensive dissection.
This study revealed that 211703 only contained a single 4.78 Mb chromosome (61.8% GC content), and no plasmids were discovered in 211703. 15 different types of resistant genes were detected in the genome of 211703, including harbored on integrative and mobilizable element (IME) Tn, and harbored on integrative and conjugative element (ICE). The ICE and IME were all carried on the chromosome of 211703 (c211703). Detailed comparison of related IMEs/ICEs showed that they shared similar conserved backbone regions, respectively. Comprehensive annotation revealed that was carried by the gene cassette of a novel integron In2148 on Tn, and was captured by an insertion sequence IS-like on the ICE of 211703. We speculated that mobile genetic elements (MGEs) such as ICE and IME facilitated the spread of resistance genes such as and .
In conclusion, this study provides an overall understanding of the genomic characterization of clinically isolated 211703, and an in-depth discussion of multiple acquisition methods of drug resistance genes in . To the best of our knowledge, this is the first report of carrying even both and , and this is the first bacterium carrying isolated from the clinical setting.
本研究旨在深入分析携带 和 基因的临床分离株 211703 的详细基因组特征。211703 是从中国一家三级医院的患者脑脊液引流样本中分离出来的。
采用免疫胶体金技术检测碳青霉烯酶 NDM。采用 VITEK2 测定 MIC 值。采用系统发育分析、基因组比较和广泛剖析方法分析 211703 的全基因组序列。
本研究表明，211703 仅含有一个 4.78 Mb 的染色体（GC 含量为 61.8%），未发现质粒。在 211703 的基因组中检测到 15 种不同类型的耐药基因，包括 位于整合子和可移动元件（IME）Tn 上，和 位于整合子和 conjugative 元件（ICE）上。ICE 和 IME 均位于 211703 染色体上（c211703）。对相关 IME/ICE 的详细比较表明，它们分别具有相似的保守骨架区。综合注释表明， 由 Tn 上新型整合子 In2148 的基因盒携带， 由 211703 的 ICE 上的插入序列 IS-like 捕获。我们推测，移动遗传元件（MGEs）如 ICE 和 IME 促进了耐药基因如 和 的传播。
总之，本研究全面了解了临床分离株 211703 的基因组特征，并深入探讨了 中耐药基因的多种获取方法。据我们所知，这是首次报道 携带 甚至同时携带 和 ，也是首次从临床环境中分离出携带 的细菌。
