Zhang Pengyu, Hao Jingchen, Zhang Yafen, Su Junfeng, Sun Guozhuang, Xie Jun, Hu Jian, Li Guocai
Department of Microbiology, Medical College, Yangzhou University, Yangzhou, 225001, China.
Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, 225009, China.
Ann Clin Microbiol Antimicrob. 2025 Jan 13;24(1):2. doi: 10.1186/s12941-024-00766-4.
Carbapenem-resistant Acinetobacter baumannii (CRAB) is recognized as a common clinical conditional pathogen with bla gene-mediated multidrug-resistance that is a significant threat to public health safety. Timely and effective infection control measures are needed to prevent their spread.
We conducted a retrospective study of CRAB patients at three teaching hospitals from 2019 to 2022. We identified bacterial isolates, collected clinical data, and performed antimicrobial susceptibility testing. Genome characteristics of isolates were investigated by whole genome sequencing. Multilocus sequence typing and phylogenetic trees were used to assess the genetic similarity of isolates. Acquired antimicrobial resistance genes and virulence factors carried in the isolated group genome were analyzed by ResFinder, PubMLST and VFDB. Sequence alignment was used to analyze genetic environment around bla. Phylogenetic tree was constructed to analyze the genetic relationship of isolates.
A total of 92 non-repetitive CRAB isolates were collected, with sputum samples accounting for the majority (94.57%, n = 87) of samples. These were distributed into ST2, with ST2 identified to have the highest prevalence of infection, accounting for 99.99% (n = 91) of all isolates. The major resistance genes identified were bla, bla, bla, and bla. Also, 92 CRAB strains showed high levels of resistance to common clinical antibiotics, but not minocycline. Meanwhile, most of the isolates carried virulence genes such as various ompA, csuA, csuB, csuC, csuD, abaI, abaR, lpxC, lpxA, and bmfRS. Single nucleotide polymorphism (SNP) analyses further indicated that the bacterial genome was progressively polymorphic with time. We analyzed the environment of the bla gene and found that CRAB accumulated in the context of prominent environmental antibiotic exposure and had longer survival times in the antibiotic environment, resulting in the tendency of bacteria to develop greater antibiotic resistance.
We find that CRAB is prevalent within the ICU and is progressively resistant to antibiotics over time. Enhanced clinical understanding and timely management of CRAB infections will be crucial to minimize or even eliminate the spread of CRAB within the ICU setting.
耐碳青霉烯类鲍曼不动杆菌（CRAB）是一种常见的临床条件致病菌，具有bla基因介导的多重耐药性，对公共卫生安全构成重大威胁。需要采取及时有效的感染控制措施以防止其传播。
我们对2019年至2022年期间三家教学医院的CRAB患者进行了回顾性研究。我们鉴定了细菌分离株，收集了临床数据，并进行了抗菌药物敏感性测试。通过全基因组测序研究分离株的基因组特征。使用多位点序列分型和系统发育树来评估分离株的遗传相似性。通过ResFinder、PubMLST和VFDB分析分离株基因组中携带的获得性抗菌耐药基因和毒力因子。使用序列比对分析bla周围的遗传环境。构建系统发育树以分析分离株的遗传关系。
共收集到92株非重复的CRAB分离株，其中痰液样本占样本的大多数（94.57%，n = 87）。这些分离株被分为ST2型，其中ST2型被确定为感染患病率最高，占所有分离株的99.99%（n = 91）。鉴定出的主要耐药基因有bla、bla、bla和bla。此外，92株CRAB菌株对常见临床抗生素表现出高水平耐药，但对米诺环素不耐药。同时，大多数分离株携带毒力基因，如各种ompA、csuA、csuB、csuC、csuD、abaI、abaR、lpxC、lpxA和bmfRS。单核苷酸多态性（SNP）分析进一步表明，细菌基因组随时间逐渐多态化。我们分析了bla基因的环境，发现CRAB在突出的环境抗生素暴露背景下积累，并且在抗生素环境中存活时间更长，导致细菌产生更大耐药性的趋势。
我们发现CRAB在重症监护病房（ICU）中普遍存在，并且随着时间的推移对抗生素的耐药性逐渐增强。加强对CRAB感染的临床认识并及时进行管理对于最大限度减少甚至消除CRAB在ICU环境中的传播至关重要。
