Presentation Type
Oral Presentation
Category
STEM (science, technology, engineering, mathematics)
Abstract/Artist Statement
Bacteria are under constant threat of infection by viruses called bacteriophages (phages).
As a result, bacteria have evolved diverse phage defense systems; however, these defenses are very specific and effectively defend against a narrow range of phages. I have discovered that the filamentous Pf phages which chronically infect the formidable bacterial pathogen Pseudomonas aeruginosa encode diverse phage defense systems. Infection by a competing phage mobilizes these systems, allowing defense systems to fluctuate in dominance in response to the ever-changing pressure of phage predation.
Mentor Name
Patrick Secor
Personal Statement
Pseudomonas aeruginosa is an opportunistic bacterial pathogen and is a leading cause of antibiotic-resistant hospital-acquired infections. Greater than 60% of P. aeruginosa clinical isolates are infected with a bacteriophage, called a Pf phage, which exists stably in the bacterial chromosome and is associated with increased bacterial virulence. Phages exist in two predominant lifestyles; Pf phages are temperate and integrate into the bacterial chromosome to exist stably in a prophage state. Their counterpart, the lytic phage, bursts their bacterial host to release progeny virions. Prophages have a clear incentive to keep their bacterial hosts alive, placing them at odds with the lytic phages’ lifestyle. However, the role of Pf phages in the dissemination of phage defense genes remains unknown. In preliminary studies, I identified Pf prophages within clinical isolates and discovered they encode diverse auxiliary genes, many of which are predicted to be involved in phage defense. Prompted by this finding, I hypothesized that Pf phage can function to mobilize phage defense genes in response to lytic phage infection. This work will provide vital insight into the role Pf phage plays in virulence evolution of P. aeruginosa, ultimately allowing for better creation of targeted therapeutics that improve patient outcomes.
Prophages encode and disseminate bacterial immune systems
UC 330
Bacteria are under constant threat of infection by viruses called bacteriophages (phages).
As a result, bacteria have evolved diverse phage defense systems; however, these defenses are very specific and effectively defend against a narrow range of phages. I have discovered that the filamentous Pf phages which chronically infect the formidable bacterial pathogen Pseudomonas aeruginosa encode diverse phage defense systems. Infection by a competing phage mobilizes these systems, allowing defense systems to fluctuate in dominance in response to the ever-changing pressure of phage predation.