Alterations in gp37 Expand the Host Range of a T4-Like Phage
Alterations in gp37 Expand the Host Range of a T4-Like Phage
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DOI：
10.1128/aem.01576-17
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发表时间：
2017-12-01
影响因子：
4.4
通讯作者：
Zhang, Wei
中科院分区：
文献类型：
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作者：
Chen, Mianmian;Zhang, Lei;Zhang, Wei
噬菌体作为抗菌剂的使用受到其宿主范围普遍狭窄的限制。本研究的目的是通过将t4样噬菌体WG01的宿主决定基因区域替换为QL01的宿主决定基因区域，使其获得另一个t4样噬菌体QL01的宿主范围。这一过程引发了WG01主机范围的直接扩展。与野生型菌株相比，WG01的后代获得了QL01和WG01的寄主范围，并且能够感染另外8种寄主细菌。WQD的寄主范围最广；因此，相应的片段命名为QD，可用于构建同源序列文库。此外，在对基因37进行测序分析后，我们确定了两种不同的机制来扩大宿主范围：(i)第一代WG01形成了没有突变的嵌合体，（ii）第二代WG01突变体由嵌合体形成。宿主范围的扩大表明，c端以外的区域可能通过改变结合位点的支持能力间接改变受体的特异性。此外，我们还发现了后代扩大宿主范围的新方法，即通过交换基因37来获得更宽的裂解温度范围。这项工作中开发的方法提供了一种快速改变或扩大噬菌体宿主范围的方法。在获得更多合适的同源序列后，可以实现针对特定临床分离物筛选噬菌体的未来临床应用。t4样噬菌体在许多噬菌体治疗应用中已被证明是安全的。使用噬菌体作为治疗剂的主要缺点包括其高度特异性的宿主范围。因此，改变或扩大t4样噬菌体的宿主范围有利于选择噬菌体进行噬菌体治疗。在本研究中，利用遗传操作扩大了t4样噬菌体WG01的宿主范围。WG01衍生物通过获得更宽的裂解温度范围，获得了扩大其宿主范围的新方法。找到了一个有潜力作为同源序列重组的序列区域。
The use of phages as antibacterial agents is limited by their generally narrow host ranges. The aim of this study was to make a T4-like phage, WG01, obtain the host range of another T4-like phage, QL01, by replacing its host-determinant gene region with that of QL01. This process triggered a direct expansion of the WG01 host range. The offspring of WG01 obtained the host ranges of both QL01 and WG01, as well as the ability to infect eight additional host bacteria in comparison to the wildtype strains. WQD had the widest host range; therefore, the corresponding fragments, named QD, could be used for constructing a homologous sequence library. Moreover, after a sequencing analysis of gene 37, we identified two different mechanisms responsible for the expanded host range: (i) the first generation of WG01 formed chimeras without mutations, and (ii) the second generation of WG01 mutants formed from the chimeras. The expansion of the host range indicated that regions other than the C-terminal region may indirectly change the receptor specificity by altering the supportive capacity of the binding site. Additionally, we also found the novel means by which subsequent generations expanded their host ranges, namely, by exchanging gene 37 to acquire a wider temperature range for lysis. The method developed in this work offers a quick way to change or expand the host range of a phage. Future clinical applications for screening phages against a given clinical isolate could be achieved after acquiring more suitable homologous sequences.IMPORTANCE T4-like phages have been established as safe in numerous phage therapy applications. The primary drawbacks to the use of phages as therapeutic agents include their highly specific host ranges. Thus, changing or expanding the host range of T4-like phages is beneficial for selecting phages for phage therapy. In this study, the host range of the T4-like phage WG01 was expanded using genetic manipulation. The WG01 derivatives acquired a novel means of expanding their host ranges by acquiring a wider temperature range for lysis. A region was located that had the potential to be used as a sequence region for homologous sequence recombination.