Comparative genomics to enable identification of genes linked to the Pseudomonas aeruginosa rugose colony phenotype

Pseudomonas aeruginosa colonizes the airways of cystic fibrosis (CF) patients, causing infections that can last for decades. During the course of these infections, P. aeruginosa undergoes a number of genetic adaptations. One such adaptation involves the formation of the rugose small colony variant (RSCV) phenotype, which is characterized by overproduction of exopolysaccharides. Here we use comparative whole genome sequencing of laboratory RSCV strains that were selected during adaptive evolution in biofilms. Also, we examined clonally related isolate pairs from previous studies of P. aeruginosa genetic diversity in CF respiratory infections, in which one isolate had smooth colony morphology and the other displayed an RSCV phenotype. This work aims to better define the landscape of genetic adaptations that occur in bacteria during biofilm growth and chronic infection.