Huang Junwei, Shen Kai, Chen Keqiang, Wu Junliang, Zhu Yijun, Shi Jingchao
Department of Clinical Laboratory, Affiliated Jinhua Hospital, Zhejiang University School of Medicine (Jinhua Municipal Central Hospital), Jinhua, Zhejiang, China.
Front Microbiol. 2025 Jul 16;16:1633493. doi: 10.3389/fmicb.2025.1633493. eCollection 2025.
is an emerging multidrug-resistant (MDR) pathogen within the genus. Although individual occurrences of or have been sporadically reported, the coexistence of both carbapenemase genes in a single strain remains extremely rare.
We performed whole-genome sequencing and conjugation assays on a bloodstream isolate of (JH112) obtained from a critically ill patient. Plasmid structure, resistance determinants, and transferability were comprehensively analyzed using assays and bioinformatic pipelines.
JH112 exhibited an extensively drug-resistant phenotype and carried two major carbapenemase genes, and , located on distinct plasmids. The gene resided on an IncFII(Yp)-type plasmid (∼110 kb) with a complete conjugation module and was successfully transferred to a recipient strain. This plasmid also harbored an O-antigen biosynthesis gene cluster, potentially enhancing host adaptation. In contrast, the gene was located on a 340 kb IncHI2/HI2A-type megaplasmid with incomplete conjugation machinery and failed to transfer under standard conditions. Both plasmids showed unique structural arrangements compared to known references. The chromosome also carried and , contributing to broad-spectrum resistance.
We report a rare clinical isolate co-harboring two carbapenemase genes on genetically distinct plasmids with divergent mobility. This highlights the species' potential role as a resistance gene reservoir and the need for enhanced molecular surveillance in both clinical and environmental settings.
是该属中一种新出现的多重耐药（MDR）病原体。虽然或的个别病例已有零星报道，但单个菌株中两种碳青霉烯酶基因共存的情况仍然极为罕见。
我们对从一名重症患者身上分离出的血液菌株（JH112）进行了全基因组测序和接合试验。使用试验和生物信息学管道全面分析了质粒结构、耐药决定因素和转移性。
JH112表现出广泛耐药表型，并携带两个主要的碳青霉烯酶基因，和，位于不同的质粒上。基因位于一个IncFII（Yp）型质粒（约110 kb）上，带有完整的接合模块，并成功转移到受体菌株中。该质粒还含有一个O抗原生物合成基因簇，可能增强宿主适应性。相比之下，基因位于一个340 kb的IncHI2/HI2A型大质粒上，接合机制不完整，在标准条件下未能转移。与已知参考序列相比，这两种质粒都显示出独特的结构排列。染色体还携带和，导致广谱耐药。
我们报告了一种罕见的临床分离株，在遗传上不同的质粒上共同携带两个碳青霉烯酶基因，且移动性不同。这突出了该物种作为耐药基因库的潜在作用，以及在临床和环境环境中加强分子监测的必要性。
