Ying Senhong, Zhang Zhirong, Xiang Rong
Precision Medicine Center, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.
Precision Medicine Center, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China; Western (Chongqing) Institute for Digital-Intelligent Medicine, Chongqing National Biomedicine Industry Park, No. 28 Gaoxin Avenue, High-tech Zone, Chongqing 401329, China.
J Glob Antimicrob Resist. 2025 Jun 22;44:180-185. doi: 10.1016/j.jgar.2025.06.009.
To characterize carbapenem-resistant Acinetobacter baumannii carrying bla genes within the Tn2006 transposon using metagenomic and whole-genome sequencing, focusing on their genetic features, antimicrobial resistance, and potential for clonal spread and horizontal gene transfer among intensive care unit (ICU) patients.
Bronchoalveolar lavage fluid samples from 28 ICU patients were analysed using metagenomic next-generation sequencing to detect pathogens and resistance genes. A. baumannii isolates underwent whole-genome sequencing for genetic diversity assessment. Antimicrobial susceptibility testing and comparative genomic analysis were performed.
Metagenomic next-generation sequencing revealed mixed infections in 71.4% of patients, identifying multiple bacteria, viruses, fungi, and Mycoplasma species. A. baumannii was detected in 25 samples, often alongside other pathogens. All isolates harboured bla within Tn2006 on the chromosome and belonged to sequence type ST2, indicating clonal dissemination despite significant genetic diversity (up to 2969 single-nucleotide polymorphism differences). The isolates were highly resistant to multiple antibiotics but remained susceptible to tigecycline and colistin. Comparative genomic analysis with 238 global carbapenem-resistant A. baumannii genomes confirmed the prevalence of the Tn2006 transposon carrying bla in ST2 strains, emphasizing the potential for rapid spread of this resistance mechanism.
The widespread presence of multidrug-resistant A. baumannii carrying bla within Tn2006 among ICU patients poses a significant public health concern. The high rate of mixed infections and the potential for horizontal gene transfer complicate infection management in critically ill patients. Enhanced infection control measures, continuous surveillance, and targeted interventions are urgently needed to prevent further dissemination of these resistant strains in hospital settings.
利用宏基因组学和全基因组测序对携带位于Tn2006转座子内bla基因的耐碳青霉烯鲍曼不动杆菌进行特征分析，重点关注其遗传特征、抗菌药物耐药性以及在重症监护病房（ICU）患者中克隆传播和水平基因转移的可能性。
对28例ICU患者的支气管肺泡灌洗液样本进行宏基因组学下一代测序分析，以检测病原体和耐药基因。对鲍曼不动杆菌分离株进行全基因组测序以评估遗传多样性。进行抗菌药物敏感性测试和比较基因组分析。
宏基因组学下一代测序显示71.4%的患者存在混合感染，鉴定出多种细菌、病毒、真菌和支原体物种。在25个样本中检测到鲍曼不动杆菌，通常与其他病原体同时存在。所有分离株在染色体上的Tn2006内均携带bla基因，属于序列类型ST2，表明尽管存在显著的遗传多样性（高达2969个单核苷酸多态性差异），但仍存在克隆传播。这些分离株对多种抗生素具有高度耐药性，但对替加环素和黏菌素仍敏感。与238个全球耐碳青霉烯鲍曼不动杆菌基因组进行的比较基因组分析证实，携带bla的Tn2006转座子在ST2菌株中普遍存在，强调了这种耐药机制快速传播的可能性。
在ICU患者中广泛存在携带位于Tn2006内bla基因的多重耐药鲍曼不动杆菌，这引起了重大的公共卫生关注。混合感染率高以及水平基因转移的可能性使重症患者的感染管理复杂化。迫切需要加强感染控制措施、持续监测和针对性干预，以防止这些耐药菌株在医院环境中进一步传播。
