Researchers at National Jewish Health have discovered a promising strategy for destroying the molecular scaffolding that can make Pseudomonas bacterial infections extremely difficult to treat in cystic fibrosis patients, wearers of contact lenses, and burn victims. Jerry Nick, MD, associate professor of medicine at National Jewish Health, and his colleagues report in the April 2009 issue of the Journal of Medical Microbiology that a long string of aspartic acid molecules disrupts the molecular bonds that hold together the structure supporting Pseudomonas biofilms.
"Once a bacterial community forms a biofilm it becomes much more difficult to treat," said Nick. "We think our discovery will pave the way for more effective treatment of Pseudomonas aeruginosa infections, which can wreak so much havoc in cystic fibrosis patients."
Biofilms are a form of bacterial colony in which bacterial cells attach to and live within an extracellular matrix, where medications and the immune system have difficulty reaching them. As a result, these infections become very difficult to treat effectively. Pseudomonas biofilms form and cause lung damage in most cystic fibrosis patients as they grow older. Pseudomonas biofilms can also form on the corneas of contact lens wearers, and in wounds and burns.
Nick and his colleagues previously showed that formation of Pseudomonas aeruginosa biofilms is enhanced by the remains of immune system cells known as neutrophils, which accumulate in vast numbers to the site of infection, then die and spill their contents. Pseudomonas builds the extracellular matrix from neutrophils' DNA, the actin structural molecules, and histones, the molecules around which DNA normally wraps inside the cell nucleus.
