Abstract
The rise of antibiotic-resistant bacterial pathogens has renewed interest in bacteriophage (phage) therapy as a potential alternative treatment. However, the evolutionary interplay between phage resistance and antibiotic susceptibility remains poorly understood, particularly in Pseudomonas species. This study investigates how phage resistance in Pseudomonas chlororaphis, a less virulent relative of P. aeruginosa, influences susceptibility to the folate pathway inhibitor trimethoprim. We hypothesized that phage-resistant mutants would exhibit altered trimethoprim sensitivity due to pleiotropic effects on efflux pumps, cell envelope structures, or biofilm formation. Using the ancestral P. chlororaphis strain (14b11), we generated phage-resistant mutants and assessed their minimum inhibitory concentration (MIC) for trimethoprim. Most mutants showed reduced growth at sub-MIC trimethoprim concentrations compared to the ancestral strain, suggesting increased susceptibility. However, some mutants displayed variable responses, indicating possible divergent resistance mechanisms. These findings suggest that phage resistance may incur fitness trade-offs affecting antibiotic susceptibility and highlight the potential for combined phage-antibiotic therapies. Given the genetic overlap between P. chlororaphis and P. aeruginosa, these results offer a safer framework for preclinical exploration and highlight the need for future molecular investigations.
Advisor
Strand, Stephanie
Department
Biology
Recommended Citation
Raj, Rithik, "The Role of Bacteriophages in Modulating Trimethoprim Resistance in Pseudomonas Aeruginosa" (2025). Senior Independent Study Theses. Paper 11273.
https://openworks.wooster.edu/independentstudy/11273
Disciplines
Bacteriology | Pathogenic Microbiology | Pharmacology | Virology
Publication Date
2025
Degree Granted
Bachelor of Arts
Document Type
Senior Independent Study Thesis
© Copyright 2025 Rithik Raj