Su Jianhui, Tan Yujing, Liu Shenshen, Zou Huanhuan, Huang Xiaoyi, Chen Siyi, Zhang Hongmei, Li Shaoting, Zeng Haiyan
School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Waihuan West Road 100, Guangzhou City, Guangdong Province, 510006, China.
BMC Microbiol. 2025 Mar 8;25(1):123. doi: 10.1186/s12866-025-03854-3.
Acinetobacter baumannii strains are a primary cause of hospital-acquired infections. This bacterium frequently causes biofilm-related infections, notably ventilator-associated pneumonia and catheter-related infections, which exhibit remarkable resistance to antibiotic treatment, posing a severe challenge in the prevention of A. baumannii infections. Therefore, strategies to eliminate the biofilm of A. baumannii in catheters are becoming increasingly important. Phages are capable of lysing bacteria and have a certain effect on the ablation of biofilms.
Sewage treatment plant water was collected for the isolation of A. baumannii phages. The morphological, host range, one-step growth, temperature and pH stability, bactericidal activity, sequencing and genomic analysis were performed to characterize the isolated phage. The three-dimensional structure of the tail fiber protein was predicted by AlphaFold3. The efficacy of phage in clearing biofilms of A. baumannii from 24-well plates and PVC catheters was also evaluated.
In this study, A. baumannii lytic phage vB_AbaM_AB4P2 was isolated from sewage treatment plant water, showing a clear plaque with halo zone. One-step growth assays unveiled a 20-minute latent period and a burst size of 61 plaque forming unit/cell (PFU/cell). At the same time, phage AB4P2 exhibited remarkable stability at pH 3-11 and temperatures 30-70 °C. Its dsDNA genome is composed of 45,680 bp with a G + C content of 46.13%. Genomic and phylogenetic analysis situated phage AB4P2 as a new species of Caudoviricetes class. Its fiber protein possesses a pectin lyase-like domain that is linked to depolymerase activity, playing a crucial role in disrupting biofilms. Additionally, it also encodes a lysis cassette comprising endolysin, holin and Rz-like spanin, yet lacks any genes responsible for antibiotic resistance and virulence factors. Phage AB4P2 can completely inhibit A. baumannii growth for 16 h. In the 24-well plate and the polyvinyl chloride (PVC) catheter model experiments, phage AB4P2 achieved a significant biofilm ablation rate and effectively killed the live bacterial cells in the biofilm.
Phage AB4P2 had good environmental stability and strong ability to inhibit the growth of A. baumannii and destroy formed biofilms by A. baumannii. It exhibits promising potential for development as an alternative environmental disinfectant against A. baumannii in the hospital.
Not applicable.
鲍曼不动杆菌菌株是医院获得性感染的主要原因。这种细菌经常引起与生物膜相关的感染，尤其是呼吸机相关性肺炎和导管相关感染，这些感染对抗生素治疗表现出显著的耐药性，给鲍曼不动杆菌感染的预防带来了严峻挑战。因此，消除导管中鲍曼不动杆菌生物膜的策略变得越来越重要。噬菌体能够裂解细菌，并且对生物膜的消融有一定作用。
收集污水处理厂的水用于分离鲍曼不动杆菌噬菌体。对分离出的噬菌体进行形态学、宿主范围、一步生长、温度和pH稳定性、杀菌活性、测序和基因组分析等表征。通过AlphaFold3预测尾纤维蛋白的三维结构。还评估了噬菌体清除24孔板和PVC导管中鲍曼不动杆菌生物膜的效果。
在本研究中，从污水处理厂的水中分离出鲍曼不动杆菌裂解性噬菌体vB_AbaM_AB4P2，其噬菌斑清晰且有晕圈。一步生长试验显示潜伏期为20分钟，裂解量为61噬菌斑形成单位/细胞（PFU/细胞）。同时，噬菌体AB4P2在pH 3至11和温度30至70°C时表现出显著的稳定性。其双链DNA基因组由45,680 bp组成，G + C含量为46.13%。基因组和系统发育分析表明噬菌体AB4P2属于长尾噬菌体目类的一个新物种。其纤维蛋白具有与解聚酶活性相关的果胶裂解酶样结构域，在破坏生物膜中起关键作用。此外，它还编码一个包含内溶素、穿孔素和Rz样跨膜蛋白的裂解盒，但缺乏任何负责抗生素抗性和毒力因子的基因。噬菌体AB4P2可在16小时内完全抑制鲍曼不动杆菌的生长。在24孔板和聚氯乙烯（PVC）导管模型实验中，噬菌体AB4P2实现了显著的生物膜消融率，并有效杀死了生物膜中的活细菌细胞。
噬菌体AB4P2具有良好的环境稳定性，以及较强的抑制鲍曼不动杆菌生长和破坏鲍曼不动杆菌形成的生物膜的能力。它在作为医院中对抗鲍曼不动杆菌的替代环境消毒剂的开发方面展现出了有前景的潜力。
不适用。
