Enzymatic Therapies for Cystic Fibrosis Biofilms

DESCRIPTION (provided by applicant): Improved therapy has transformed cystic fibrosis (CF) from a disease characterized by death in early childhood to a chronic illness with a median survival of approximately 30 years. However, there is still no cure for this devastating genetic disease affecting approximately 30,000 Americans and many questions about molecular pathogenesis, with important implications for therapy, remain to be answered. Approximately 80% of cystic fibrosis patients develop Pseudomonas aeruginosa infections of the lungs, which are a major cause of morbidity and mortality in this genetic disease. These chronic infections are resistant to antibiotic therapies. Recent studies suggest that the antibiotic resistance of P. aeruginosa in the CF lung is due to the formation of biofilms that are impervious to antibiotics. The P. aeruginosa biofilm is composed of bacterial cells surrounded by a three dimensional matrix of diverse substances, including polysaccharides, proteins, nucleic acids, and lipids; the major structural component appears to be polysaccharides produced by the P. aeruginosa cells. The proposed work will systematically test the ability of 80 polysaccharide-degrading enzymes to breakdown or weaken the P. aeruginosa biofilm. A sensitivetest to determine the amount of polysaccharide degradation has been developed and those enzymes that actively degrade the biofilm will be combined to make a synergistic enzyme cocktail. The optimal enzyme mixture will then be tested in combination with Tobramycin to test the hypothesis that enzymatic degradation of the P. aeruginosa polysaccharide biofilm components will increase the sensitivity of P. aeruginosa to antibiotic treatment, resulting in improved outcomes for patients. PUBLIC HEALTH RELEVANCE: There is an unmet need for new therapies to extend the life and health of cystic fibrosis patients, a fatal disease affecting tens of thousands of Americans. Pseudomonas aeruginosa is the pathogen responsible for most CF patients succumbing to thisgenetic disease. The proposed development of enzymes that attack and degrade the antibiotic resistant biofilm formed by Pseudomonas aeruginosa has the potential to extend the quality and quantity of life, with important implications for numerous other diseases that are impacted by the formation of biofilms.