Scientists from the Research Institute of the McGill University Health Centre and SickKids have developed a new enzyme technique aimed at destroying biofilms, which form when bacteria adheres to surfaces and produces a slimy substance that helps it stick to material.
Biofilms are also responsible for thousands of hospital-acquired infections every year within North America. Because they create hardened sugar molecules that prevent anitbiotics from reaching target sites within microbes, they are very difficult to remove.
Findings recently published in Proceedings of the National Academy of Sciences (PNAS) show some success, and what is being called “the first strategy that has ever been effective in eradicating mature biofilms.”
“We were able to use the microbe’s own tools against them to attack and destroy the sugar molecules that hold the biofilm together,” said the study’s co-principal investigator, Dr. Don Sheppard, director of the Division of Infectious Diseases at the MUHC and scientist from the Infectious Diseases and Immunity in Global Health Program at the RI-MUHC, in a press release. “Rather than trying to develop new individual ‘bullets’ that target single microbes we are attacking the biofilm that protects those microbes by literally tearing down the walls to expose the microbes living behind them. It’s a completely new and novel strategy to tackle this issue.”
The team found enzymes that cut up sugar molecules, which glue biofilms together, and discovered a way to use these enzymes to “degrade the sugar armour, exposing the microbe to antibiotics and host defenses.”
“When we took the enzymes from bacteria and applied them to the fungi, we found that they worked in the same way on the fungi biofilm; which was surprising,” says the study’s co-principal investigator, Dr. P. Lynne Howell, who is also a professor in the Department of Biochemistry at the University of Toronto. “What’s key is that this approach could be a universal way of being able to leverage the microbes’ own systems for degrading biofilms. This has bigger implications across many microbes, diseases and infections.”
Photo courtesy of McGill University. The fungus Aspergillus fumigatus (in red) produces a sticky sugar molecule (in green) in order to make its biofilm.