School of Life Sciences, Arizona State University, Tempe, AZ 85281, USA.
Biodesign Institute, Arizona State University, Tempe, AZ 85281, USA.
G3 (Bethesda). 2022 Nov 4;12(11). doi: 10.1093/g3journal/jkac244.
Bacteriophages, infecting bacterial hosts in every environment on our planet, are a driver of adaptive evolution in bacterial communities. At the same time, the host range of many bacteriophages-and thus one of the selective pressures acting on complex microbial systems in nature-remains poorly characterized. Here, we computationally inferred the putative host ranges of 40 cluster P mycobacteriophages, including members from 6 subclusters (P1-P6). A series of comparative genomic analyses revealed that mycobacteriophages of subcluster P1 are restricted to the Mycobacterium genus, whereas mycobacteriophages of subclusters P2-P6 are likely also able to infect other genera, several of which are commonly associated with human disease. Further genomic analysis highlighted that the majority of cluster P mycobacteriophages harbor a conserved integration-dependent immunity system, hypothesized to be the ancestral state of a genetic switch that controls the shift between lytic and lysogenic life cycles-a temperate characteristic that impedes their usage in antibacterial applications.
噬菌体在我们星球上的每一种环境中感染细菌宿主，是推动细菌群落适应性进化的因素之一。与此同时，许多噬菌体的宿主范围——因此也是对自然界中复杂微生物系统起作用的选择性压力之一——仍未得到充分描述。在这里，我们通过计算推断了 40 个聚类 P 分枝杆菌噬菌体的可能宿主范围，其中包括 6 个亚群（P1-P6）的成员。一系列比较基因组分析表明，亚群 P1 的分枝杆菌噬菌体仅限于分枝杆菌属，而亚群 P2-P6 的分枝杆菌噬菌体可能也能够感染其他属，其中有几个属通常与人类疾病有关。进一步的基因组分析强调，大多数聚类 P 分枝杆菌噬菌体都具有保守的整合依赖性免疫防御系统，这被假设为控制裂解和溶源生命周期之间转变的遗传开关的原始状态——这是一种温和的特性，阻碍了它们在抗菌应用中的使用。
