Genomic sequencing of Pseudomonas aeruginosa lineages evolved under antibiotic pressure in single nutrient medium
Pseudomonas aeruginosa is the predominant pathogen in adult cystic fibrosis (CF) lung infections, notable for its metabolic versatility and rapid development of antimicrobial resistance. Although metabolic fitness costs and reduced antibiotic sensitivity have both been linked to nutrient conditions, the impact of specific nutrients on antibiotic resistance evolution remains underexplored. We conducted adaptive laboratory evolution under single-nutrient conditions with incrementally increasing concentrations of ciprofloxacin, colistin, and tobramycin, comparing the results to nutrient-rich synthetic CF sputum medium. Whole-genome sequencing and partial least squares discriminant analysis revealed distinct mutational patterns for tobramycin and ciprofloxacin, while colistin showed broader variation across conditions. These findings underscore the importance of including physiologically relevant nutrient conditions in antibiotic resistance studies and advance our understanding of the evolutionary trajectories in CF lung infections.