Research has revealed that a common bacteria found in the lungs of those with cystic fibrosis produces a slime that acts as a defence against a variety of therapeutic drugs.
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, headed the research.
A life threatening-condition caused by a genetic mutation, cystic fibrosis causes persistent lung infections and gradually reduces a person’s breathing capacity. A common strain of bacteria, Pseudomonas aeruginosa, often thrives in the lungs of people with cystic fibrosis, and when a P. aeruginosa infection is established, it can be extremely hard to remove.
The research showed that stubborn bacteria dwelling in the lungs of cystic fibrosis patients produce a carbohydrate slime, which both shields them against antibiotics and also mucus-reducing drugs.
“We found the first direct evidence that these carbohydrates are produced at the sites of infection,” Dr Jennings said. “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.”
She explained that the research supports a theory that these carbohydrates also support the aggregation of these bacteria in the lungs of cystic fibrosis patients.
“This is important 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 promote bacterial aggregation may facilitate new therapeutic approaches aimed at digesting the carbohydrates holding bacterial cells together.”
Source: Medical Xpress
Journal information: Laura K. Jennings et al. Pseudomonas aeruginosa aggregates in cystic fibrosis sputum produce exopolysaccharides that likely impede current therapies, Cell Reports (2021). DOI: 10.1016/j.celrep.2021.108782
