Carbohydrate That Promotes Biofilm May Be Key to Treating Pseudomonas Infections

Drugs targeting a component of biofilm — the glue-like layer secreted by bacteria in cystic fibrosis (CF) patients’ lungs — could increase the bacteria’s vulnerability to antibiotics and natural immune reactions, according to a new study.

Researchers discovered that a specific carbohydrate in biofilm — Psl — makes it stiffer and, over time, increasingly difficult to break down.

Their findings were in the study, “Evolutionary adaptations of biofilms infecting cystic fibrosis lungs promote mechanical toughness by adjusting polysaccharide production,” published in the journal npj Biofilms and Microbiomes.

The main reason Pseudomonas aeruginosa lung infections in CF are so difficult to treat is the thick layer of  biofilm the bacteria produce. Biofilm forms a protective layer that keeps antibiotics and immune components from reaching the bacteria.

“Mechanical removal is often required to clear biofilm infections,” researchers at the University of Texas at Austin noted.

The team found that Psl contributes to biofilm’s toughness by binding to another molecule. In CF patients, biofilm’s stiffness increases over time, so a treatment that makes it easier to break down biofilm would help the immune system fight a bacterial infection.

“And that would be awesome because the standard antibiotic for these infections is tobramycin, which is nasty,” Vernita Gordon, PhD, assistant professor of physics, said in a press release. “It causes kidney damage and deafness. The secondary and tertiary antibiotics are even more awful. So if you can reduce antibiotic treatment that’s needed because you’ve made the patient’s immune system more effective, that would be a big benefit.”

Gordon noted that targeting Psl would be beneficial in cases where the bacteria have become resistant to treatment.

“And that’s important given how fast antibiotic resistance is increasing,” she said. “We need new ways to approach these diseases that are in an antibiotics arms race with us, because it’s pretty clear, the bacteria are going to win that race.”

Biofilm infections affect about 17 million Americans each year.

“This new perspective has the potential to improve the lives of a lot of people,” Gordon said.