Division of Clinical Microbiology Laboratory, Toho University Ohashi Medical Center, Meguro, Tokyo, Japan.
Department of Infection and Prevention, Toho University Ohashi Medical Center, Meguro, Tokyo, Japan.
Microbiol Spectr. 2024 Oct 3;12(10):e0056224. doi: 10.1128/spectrum.00562-24. Epub 2024 Aug 20.
We present the identification and characterization of the complete genome of metronidazole (MTZ)-resistant strain TOH-2715 [minimum inhibitory concentration (MIC): 8 mg/L], isolated from the urine of an elderly Japanese woman, as well as details of its mobile genetic elements (MGEs) containing antimicrobial resistance (AMR) genes and its relationship with other bacterial species determined using whole-genome sequencing (WGS) data. TOH-2715 possessed two chromosomes with putative MGEs containing AMR genes. Two AMR-related MGE regions were present in chromosome 2. MGE-region 1 (7,821 bp) included Tn, where was located, and MGE-region 2 (58.8 Kbp) included the integrative and conjugative element (ICE), where (Q) and were located. The genetic structure of the ICE of TOH-2715 was similar to that of CTn-family transposons, where and (Q) are located. A search of public databases revealed that was present in spp., including , and was partially composed of a Tn-like element lacking the efflux transporter gene and the Crp/Fnr family transcriptional regulator gene in some cases. Core ICE gene analysis showed that ICEs similar to that of TOH-2715 were present in spp. and spp., suggesting horizontal gene transfer among anaerobes. This is the report of WGS analysis of an MTZ-resistant clinical strain of (TOH-2715) with Tn encoding . Other submitted genomes have described the presence of , but none of them have described MTZ resistance. Additionally, we described putative MGE regions containing the AMR gene within the genus and among anaerobes, raising concerns about the future spread of among anaerobes.
Metronidazole (MTZ) is an important antimicrobial agent in anaerobic infections and is widely used in clinical settings. The rate of MTZ resistance in anaerobic bacteria has been increasing in recent years, and the gene (nitro-imidazole reductase) is one of the resistance mechanisms. is found in humans in the urinary tract and vagina and is known to cause infections in some cases. One of the genes, , has recently been discovered in this species of bacteria, but there are no reports of antimicrobial resistance (AMR)-related regions in its whole genome level. In this study, we analyzed the AMR region of -positive derived from clinical specimens based on comparisons with other anaerobic genomes. was found to be engaged in horizontal gene transfer with other anaerobic bacteria, and the future spread of the gene is a concern.
我们介绍了从一位日本老年女性尿液中分离出的甲硝唑（MTZ）耐药菌株 TOH-2715[最小抑菌浓度（MIC）：8 mg/L]的完整基因组的鉴定和特征，以及其包含抗菌药物耐药（AMR）基因的移动遗传元件（MGE）的详细信息，以及使用全基因组测序（WGS）数据确定的其与其他细菌物种的关系。TOH-2715 具有两个可能包含 AMR 基因的染色体。染色体 2 中存在两个与 AMR 相关的 MGE 区域。MGE 区域 1（7821 bp）包含 Tn，其中 位于其中，而 MGE 区域 2（58.8 Kbp）包含整合和共轭元件（ICE），其中 位于其中和 。TOH-2715 的 ICE 的遗传结构与 CTn 家族转座子相似，其中 和 位于其中。对公共数据库的搜索表明， 存在于 spp.中，包括 ，并且在某些情况下部分由缺乏外排转运蛋白基因 和 Crp/Fnr 家族转录调节基因的 Tn 样元件组成。核心 ICE 基因分析表明，与 TOH-2715 相似的 ICE 存在于 spp.和 spp.中，表明厌氧菌之间存在水平基因转移。这是对甲硝唑耐药临床株（TOH-2715）进行 WGS 分析的报告，该株含有编码 的 Tn。其他已提交的基因组描述了 的存在，但没有一个描述了甲硝唑耐药性。此外，我们描述了在属内和厌氧菌中包含 AMR 基因的假定 MGE 区域，这引发了对未来厌氧菌中 传播的担忧。
甲硝唑（MTZ）是厌氧感染中一种重要的抗菌药物，在临床环境中广泛使用。近年来，厌氧细菌对 MTZ 的耐药率一直在上升，而 基因（硝基-咪唑还原酶）是耐药机制之一。 在人类的泌尿道和阴道中被发现，已知在某些情况下会引起感染。该物种的细菌中最近发现了 基因之一， ，但在其全基因组水平上没有报告与抗菌药物耐药性（AMR）相关的区域。在这项研究中，我们基于与其他厌氧基因组的比较，分析了源自临床标本的阳性 株的 AMR 区域。 被发现与其他厌氧细菌进行水平基因转移，并且 基因的未来传播令人担忧。
