Microorganisms utilize vile methodology to vanquish antibody that battle cystic fibrosis

University of Montana researchers and their partners have found a slimy strategy used by bacteria to conquer antibiotics and other medications used to combat infections afflicting individuals with cystic fibrosis.

Cystic fibrosis is a life-threatening illness which causes persistent lung infections and limits an individual’s ability to breathe over time. A frequent strain of bacteria, Pseudomonas aeruginosa, often thrives from the lungs of individuals with cystic fibrosis, as well as in wounds from burns or diabetic ulcers. Once a P. aeruginosa infection is established, it can be incredibly difficult to cure, despite repeated courses of antibiotics.

Dr. Laura Jennings, a research assistant professor in UM’s Division of Biological Sciences and an affiliate with the University’s Center for Translational Medicine, said their research showed that the stubborn germs living in the lungs of cystic fibrosis patients produce a self-produced carbohydrate slime. And this slime makes the bacteria more resistant to the antibiotics prescribed by physicians, as well as drugs that decrease the thickness of mucus.

We found the first direct evidence that these carbohydrates are produced at the sites of infection. We showed that one of the carbohydrates, called Pel, sticks to extracellular DNA, which is abundant in the thick mucus secretions prominent in cystic fibrosis lungs. This interaction makes a slimy protective layer around the bacteria, making them harder to kill,” she said. “As such, it reduces the pathogen’s susceptibility to antibiotics and drugs aimed at reducing the thickness of airway mucus by digesting DNA.”

Dr. Laura Jennings, Research Assistant Professor, Division of Biological Sciences, Affiliate, Center for Translational Medicine, University of Montana

She said the work supports a theory that it’s the carbohydrates that group, or aggregate, the bacteria in cystic fibrosis lungs.

“This is significant because we know that physically breaking up bacterial aggregates can restore bacterial susceptibility to killing with antibiotics and cells of the immune system,” Jennings said. “Therefore, understanding the mechanisms that encourage bacterial aggregation may facilitate new therapeutic approaches directed at digesting the carbs holding bacterial cells together.”

The study also suggests that the carbohydrate Pel likely diminishes the effectiveness of the most commonly used therapeutics for cystic fibrosis, which are inhaled antibiotics and a drug that breaks down the depth of the airway mucus, which makes it easier to cough up.