Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China.
Sucheng District Animal Husbandry and Veterinary Station, Suqian, 223800, China.
BMC Microbiol. 2020 Jun 1;20(1):141. doi: 10.1186/s12866-020-01811-w.
Aeromonas hydrophila is an important water-borne pathogen that leads to a great economic loss in aquaculture. Along with the abuse of antibiotics, drug-resistant strains rise rapidly. In addition, the biofilms formed by this bacterium limited the antibacterial effect of antibiotics. Bacteriophages have been attracting increasing attention as a potential alternative to antibiotics against bacterial infections.
Five phages against pathogenic A. hydrophila, named N21, W3, G65, Y71 and Y81, were isolated. Morphological analysis by transmission electron microscopy revealed that phages N21, W3 and G65 belong to the family Myoviridae, while Y71 and Y81 belong to the Podoviridae. These phages were found to have broad host spectra, short latent periods and normal burst sizes. They were sensitive to high temperature but had a wide adaptability to the pH. In addition, the phages G65 and Y81 showed considerable bacterial killing effect and potential in preventing formation of A. hydrophila biofilm; and the phages G65, W3 and N21 were able to scavenge mature biofilm effectively. Phage treatments applied to the pathogenic A. hydrophila in mice model resulted in a significantly decreased bacterial loads in tissues.
Five A. hydrophila phages were isolated with broad host ranges, low latent periods, and wide pH and thermal tolerance. And the phages exhibited varying abilities in controlling A. hydrophila infection. This work presents promising data supporting the future use of phage therapy.
嗜水气单胞菌是一种重要的水生病原体，它会给水产养殖业造成巨大的经济损失。随着抗生素的滥用，耐药菌株迅速增加。此外，该细菌形成的生物膜限制了抗生素的抗菌效果。噬菌体作为抗生素治疗细菌感染的替代品，正受到越来越多的关注。
分离到了 5 株针对致病性嗜水气单胞菌的噬菌体，分别命名为 N21、W3、G65、Y71 和 Y81。透射电子显微镜形态分析表明，噬菌体 N21、W3 和 G65 属于肌尾噬菌体科，而 Y71 和 Y81 属于短尾噬菌体科。这些噬菌体具有广泛的宿主谱、较短的潜伏期和正常的爆发量。它们对高温敏感，但对 pH 值有较宽的适应性。此外，噬菌体 G65 和 Y81 表现出相当的杀菌效果和抑制嗜水气单胞菌生物膜形成的潜力；噬菌体 G65、W3 和 N21 能够有效地清除成熟的生物膜。噬菌体处理应用于小鼠模型中的致病性嗜水气单胞菌，导致组织中的细菌负荷明显降低。
分离到了 5 株具有广泛宿主范围、潜伏期短、pH 值和热耐受性宽的嗜水气单胞菌噬菌体。并且这些噬菌体在控制嗜水气单胞菌感染方面表现出不同的能力。这项工作提供了有前途的噬菌体治疗数据支持。
