Pseudomonas aeruginosa filamentous (Pf) bacteriophages are important factors contributing to the pathogenicity of this opportunistic bacterium, including biofilm formation and suppression of bacterial phagocytosis by macrophages. In addition, the capacity of Pf phages to form liquid crystal structures and their high negative charge density makes them potent sequesters of cationic antibacterial agents, such as aminoglycoside antibiotics or host antimicrobial peptides. Therefore, Pf phages have been proposed as a potential biomarker for risk of antibiotic resistance development. The majority of studies describing biological functions of Pf viruses have been performed with only three of them: Pf1, Pf4, and Pf5. However, our analysis revealed that Pf phages exist as two evolutionary lineages (I and II), characterized by substantially different structural/morphogenesis properties, despite sharing the same integration sites in the host chromosomes. All aforementioned model Pf phages are members of the lineage I. Hence, it is reasonable to speculate that their interactions with P. aeruginosa and impact on its pathogenicity may be not completely extrapolated to the lineage II members. Furthermore, in order to organize the present numerical nomenclature of Pf phages, we propose a more informative approach based on the insertion sites, that is, Pf-tRNA-Gly, -Met, -Sec, -tmRNA, and -DR (direct repeats), which are fully compatible with one of five types of tyrosine integrases/recombinases XerC/D carried by these viruses. Finally, we discuss possible evolutionary mechanisms behind this division and consequences from the perspective of virus–virus, virus–bacterium, and virus–human interactions.

中文翻译：

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铜绿假单胞菌丝状噬菌体的两个谱系——结构一致性优于整合偏好。


铜绿假单胞菌丝状 (Pf) 噬菌体是导致这种机会性细菌致病性的重要因素，包括生物膜形成和巨噬细胞抑制细菌吞噬作用。此外，Pf噬菌体形成液晶结构的能力及其高负电荷密度使其成为阳离子抗菌剂（例如氨基糖苷类抗生素或宿主抗菌肽）的有效螯合剂。因此，Pf 噬菌体被提议作为抗生素耐药性发展风险的潜在生物标志物。大多数描述 Pf 病毒生物学功能的研究仅使用其中的三种病毒进行：Pf1、Pf4 和 Pf5。然而，我们的分析表明，Pf 噬菌体以两个进化谱系（I 和 II）存在，尽管在宿主染色体上共享相同的整合位点，但其结构/形态发生特性却截然不同。所有上述模型 Pf 噬菌体都是谱系 I 的成员。因此，有理由推测它们与铜绿假单胞菌的相互作用以及对其致病性的影响可能不能完全外推到谱系 II 成员。此外，为了组织 Pf 噬菌体目前的数字命名法，我们提出了一种基于插入位点的信息更丰富的方法，即 Pf-tRNA-Gly、-Met、-Sec、-tmRNA 和 -DR（直接重复序列） ），与这些病毒携带的五种酪氨酸整合酶/重组酶 XerC/D 之一完全兼容。最后，我们从病毒与病毒、病毒与细菌以及病毒与人类相互作用的角度讨论了这种划分背后可能的进化机制和后果。