Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben-Gurion University of the Negev, P.O. Box 653, Be'er Sheva 8410501, Israel.
The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kongens Lyngby, Denmark.
Viruses. 2020 Oct 6;12(10):1132. doi: 10.3390/v12101132.
Bacteriophages (phages), viruses that infect bacteria, are considered to be highly host-specific. To add to the knowledge about the evolution and development of bacteriophage speciation toward its host, we conducted a 21-day experiment with the broad host-range bacteriophage phage P14. We incubated the phage, which was previously isolated and enriched with the Alphaproteobacteria H14, with the Betaproteobacteria H5. During the experiment, we observed an increase in the phage's predation efficacy towards H5. Furthermore, genome analysis and the comparison of the bacteriophage's whole genome indicated that rather than being scattered evenly along the genome, mutations occur in specific regions. In total, 67% of the mutations with a frequency higher than 30% were located in genes that encode tail proteins, which are essential for host recognition and attachment. As control, we incubated the phage with the Alphaproteobacteria H8. In both experiments, most of the mutations appeared in the gene encoding the tail fiber protein. However, mutations in the gene encoding the tail tubular protein B were only observed when the phage was incubated with H5. This highlights the phage's tail as a key player in its adaptation to different hosts. We conclude that mutations in the phage's genome were mainly located in tail-related regions. Further investigation is needed to fully characterize the adaptation mechanisms of the phage P14.
噬菌体（phages）是感染细菌的病毒，被认为具有高度的宿主特异性。为了增加对噬菌体向宿主进化和发展的了解，我们用广谱宿主范围的噬菌体 phage P14 进行了为期 21 天的实验。我们用先前从 Alphaproteobacteria H14 中分离和富集的噬菌体 phage P14 与 Betaproteobacteria H5 一起培养。在实验过程中，我们观察到噬菌体对 H5 的捕食效率增加。此外，基因组分析和噬菌体全基因组的比较表明，突变不是均匀分布在基因组中，而是发生在特定区域。总的来说，频率高于 30%的突变中有 67%位于编码尾部蛋白的基因中，尾部蛋白对于宿主识别和附着至关重要。作为对照，我们用 Alphaproteobacteria H8 培养噬菌体。在这两个实验中，大多数突变出现在编码尾纤维蛋白的基因中。然而，只有当噬菌体与 H5 一起培养时，才观察到编码尾部管状蛋白 B 的基因发生突变。这突出了噬菌体的尾部在适应不同宿主方面的关键作用。我们得出结论，噬菌体基因组中的突变主要位于与尾部相关的区域。需要进一步研究才能充分表征 phage P14 的适应机制。
