抗生素耐药性的出现和传播带来了严重的环境和健康挑战。噬菌体疗法作为具有巨大潜力的对抗抗生素耐药性的替代方法已引起人们的注意。然而,噬菌体治疗的障碍之一是噬菌体抗性,它可以通过基因突变获得,其次是表型变异的后果。因此,了解噬菌体-宿主相互作用的潜在机制将为我们提供如何优化噬菌体治疗的更多细节.在这项研究中,分离了三种裂解噬菌体(phipa2,phipa4和phipa10),以研究铜绿假单胞菌中的噬菌体抗性和潜在的适应性权衡。具体来说,在噬菌体抗性突变体phipa2-R和phipa4-R中,在基因pilT和pilB中发生了赋予抗性的突变,两者都是IV型菌毛(T4P)生物合成所必需的。在噬菌体抗性突变体phipa10-R中,〜294kb的大染色体缺失,包括hmgA(匀浆1,2-双加氧酶)和galU(UTP-葡萄糖-1-磷酸尿酰转移酶)基因,观察并赋予噬菌体phipa10抗性。Further,我们展示了这些噬菌体抗性突变中相关权衡的例子,例如,运动受损,减少生物膜形成,和增加抗生素敏感性。总的来说,我们的研究揭示了抗性介导的基因突变及其多效性表型,进一步强调了噬菌体-宿主相互作用令人印象深刻的复杂性和多样性,以及它们在控制这种重要病原体中的细菌疾病时带来的挑战。重要性对抗噬菌体抗性是噬菌体治疗面临的主要挑战之一。为了克服这一挑战,了解细菌进化过程需要有关噬菌体-宿主相互作用机制的详细信息。在这项研究中,我们确定了导致噬菌体耐药性的IV型菌毛(T4P)和O-抗原生物合成关键步骤的突变,并提供了噬菌体捕食如何导致宿主表型和适应性变异的新证据.一起,我们的研究结果进一步增加了噬菌体-宿主相互作用的基本知识,以及它们如何调节假单胞菌细胞行为的不同方面.
The emergence and spread of antibiotic resistance pose serious environmental and health challenges. Attention has been drawn to phage therapy as an alternative approach to combat antibiotic resistance with immense potential. However, one of the obstacles to phage therapy is phage resistance, and it can be acquired through genetic mutations, followed by consequences of phenotypic variations. Therefore, understanding the mechanisms underlying phage-host interactions will provide us with greater detail on how to optimize phage therapy. In this study, three lytic phages (phipa2, phipa4, and phipa10) were isolated to investigate phage resistance and the potential fitness trade-offs in Pseudomonas aeruginosa. Specifically, in phage-resistant mutants phipa2-R and phipa4-R, mutations in conferring resistance occurred in genes pilT and pilB, both essential for type IV pili (T4P) biosynthesis. In the phage-resistant mutant phipa10-R, a large chromosomal deletion of ~294 kb, including the hmgA (homogentisate 1,2-dioxygenase) and galU (UTP-glucose-1-phosphate uridylyltransferase) genes, was observed and conferred phage phipa10 resistance. Further, we show examples of associated trade-offs in these phage-resistant mutations, e.g., impaired motility, reduced biofilm formation, and increased antibiotic susceptibility. Collectively, our study sheds light on resistance-mediated genetic mutations and their pleiotropic phenotypes, further emphasizing the impressive complexity and diversity of phage-host interactions and the challenges they pose when controlling bacterial diseases in this important pathogen. IMPORTANCE Battling phage resistance is one of the main challenges faced by phage therapy. To overcome this challenge, detailed information about the mechanisms of phage-host interactions is required to understand the bacterial evolutionary processes. In this study, we identified mutations in key steps of type IV pili (T4P) and O-antigen biosynthesis leading to phage resistance and provided new evidence on how phage predation contributed toward host phenotypes and fitness variations. Together, our results add further fundamental knowledge on phage-host interactions and how they regulate different aspects of Pseudomonas cell behaviors.