BioProject

Six strains of Pseudomonas aeruginosa, ranging from laboratory to environmental and clinical isolates and containing a diverse prophage assortment, were co-inoculated into a porcine full-thickness burn wound model. More...

Six strains of Pseudomonas aeruginosa, ranging from laboratory to environmental and clinical isolates and containing a diverse prophage assortment, were co-inoculated into a porcine full-thickness burn wound model. Hyperbiofilm producing stable variants were isolated 3, 14, and 28 days post infection. Of the six strains inoculated into the wound, only the laboratory strains, PA14 and PAO1, evolved phenotypic variants over the course of the experiment. Short read genome sequencing revealed a remarkable level of mutational parallelism in the frequently observed wsp pathway in PA14 (PRJNA491911). Mutations in this operon increased the intracellular levels of cyclic-di-GMP that in turn generated a hyperbiofilm forming phenotype. However, no driver mutations were detected by short read genome sequencing in many of the evolved PAO1 variants. Instead, long read sequencing and de novo assemblies revealed that interstrain movement of prophage elements from the clinical and environmental strains occurred, with PAO1 as the primary recipient strain. Parallelism was observed in these recombination events, where the sites of phage insertion disrupted genes encoding phosphodiesterases and global regulators, again leading to increased cyclic-di-GMP levels and subsequently a hyperbiofilm forming phenotype. The implications of prophage-mediated adaptation are broad, as even transient members of microbial communities can cause the evolution of persistent phenotypes associated with poor clinical outcomes. Less...