Targeted deletion of Pf prophages from diverse isolates has differential impacts on quorum sensing and virulence traits.

is an opportunistic bacterial pathogen that commonly causes medical hardware, wound, and respiratory infections. Temperate filamentous Pf phages that infect impact numerous virulence phenotypes. Most work on Pf phages has focused on Pf4 and its host PAO1. Expanding from Pf4 and PAO1, this study explores diverse Pf phages infecting clinical isolates. We describe a simple technique targeting the Pf lysogeny maintenance gene, (), that enables the effective elimination of Pf prophages from diverse hosts. The gene shows diversity among different Pf phage isolates; however, all examined alleles encode the DUF5447 domain. We demonstrate that deletion results in prophage excision but not replication, leading to total prophage loss, indicating a role for lysis/lysogeny decisions for the DUF5447 domain. This study also assesses the effects different Pf phages have on host quorum sensing, biofilm formation, pigment production, and virulence against the bacterivorous nematode . We find that Pf phages have strain-specific impacts on quorum sensing and biofilm formation, but nearly all suppress pigment production and increase avoidance behavior. Collectively, this research not only introduces a valuable tool for Pf prophage elimination from diverse isolates but also advances our understanding of the complex relationship between and filamentous Pf phages.IMPORTANCE is an opportunistic bacterial pathogen that is frequently infected by filamentous Pf phages (viruses) that integrate into its chromosome, affecting behavior. Although prior work has focused on Pf4 and PAO1, this study investigates diverse Pf in clinical isolates. A simple method targeting the deletion of the Pf lysogeny maintenance gene () effectively eliminates Pf prophages from clinical isolates. The research evaluates the impact Pf prophages have on bacterial quorum sensing, biofilm formation, and virulence phenotypes. This work introduces a valuable tool to eliminate Pf prophages from clinical isolates and advances our understanding of and filamentous Pf phage interactions.