P. Aeruginosa Case Studies

P. aeruginosa has been studied extensively for over 100 years due to its role in chronic infections of the urinary tract, pneumonia in cystic fibrosis patients, its ability to delay wound healing, and in foreign-body infections (biomaterial implants and devices such as catheters and prosthetics).2,4,14-17 Biofilm-based chronic infections caused by P. aeruginosa affect millions of people and are the leading cause of morbidity and mortality in patients suffering from cystic fibrosis.18,19 Growth in biofilms is associated with an increased mutation rate, known as the mutator phenotype, which is thought to contribute to antibiotic resistance.6,7,9 This mutator phenotype is characterized by a few to one thousand-fold the mutation frequency of the common laboratory strain (PAO1).9,20-22 However, it is not currently known what controls P. aeruginosa biofilm growth or how biofilm growth activates the mutator phenotype.6,7,9,23-25 Although it has been suggested that genes that …show more content…
For example, recently, it has been shown that epigenetic modifications in the closely related gamma-proteobacteria, Salmonella enterica, can regulate the transition from planktonic to biofilm growth, and that this transition is caused by changes in gene expression induced by epigenetics.27 Additionally, it has been demonstrated that an epigenetic switch in H. influenzae can control virulence and the transition to biofilm growth.28 Epigenetic mechanisms such as DNA methylation are now understood to play a significant role in the regulation of virulence-associated functions in pathogenic bacteria, biofilm growth, transcription, DNA mismatch repair, and replication initiation.12,27,29-36 Our proposed research will further our understanding of the role of epigenetic modifications in P. aeruginosa and help determine if it confers a survival advantage to the persisting, antibiotic-resistant mutator