Discovery could aid fight against cystic fibrosis infection

Harvard Medical School researchers have discovered one way that a hardy disease-causing bacteria could be surviving in the lungs of chronically infected cystic fibrosis patients. “This work is important because pathogenic bacteria such as Pseudomonas aeruginosa use protein secretion systems to cause disease in their hosts,” said Joseph Mougous, lead author of the study published in the June 9, 2006, issue of Science. “In the case of Pseudomonas aeruginosa, the host may be a cancer patient with a weakened immune system, a burn patient, or a person with cystic fibrosis.”

Pseudomonas aeruginosa (PA), a pathogen that infects more than 80 percent of cystic fibrosis patients, is a leading cause of these patients’ death. PA is difficult to treat because it is resistant to many drugs.

“Since we know so little about what this bacterium is up to while it’s engaged in these chronic infections, the discovery of this protein secretion system might lead to finding a new target for treatments,” said Mougous, a research fellow in the Harvard Medical School Department of Microbiology and Molecular Genetics.

The research was supported in part by grants from the National Institutes of Health, the Damon Runyon Cancer Research Foundation, and the U.S. Department of Energy, Office of Biological and Environmental Research.