Canadian team helps find way to break through armour of dangerous biofilms
Published Saturday, June 24, 2017 10:00PM EDT
Last Updated Saturday, June 24, 2017 11:30PM EDT
Not many Canadians have ever heard of "biofilms," but doctors and infectious diseases experts know them well. The slimy, glue-like sheets of bacteria or fungi can grow on tissues or wounds, forming a protective layer around themselves that make it difficult to kill the infections.
Now Canadian researchers say they may have found a way of fighting biofilms by breaking up their protective coatings.
Not all biofilms are dangerous; there is likely a biofilm of plaque on your teeth right now, if it's been a while since you last brushed.
But some biofilms are dangerous and can progress into serious infections, says Dr. Don Sheppard, the director of the division of Infectious Diseases at the McGill University Health Centre in Montreal.
"They can attach to skin and wounds. They can attach to prosthetic devices, like IV catheters, urinary catheters, the artificial hips that we put inside people. And they can adhere to those surfaces with a strength that exceeds that of crazy glue," he says.
Because biofilms work together to form a kind of armour around themselves, colonies of bacteria or fungi can easily fight off immune system attacks, and even high doses of antibiotics. That leaves doctors with little in their arsenal to fight them, says Lynne Howell, a senior scientist in in molecular medicine at SickKids Hospital in Toronto.
"The fact we don't have any way to prevent or treat them is a major problem," she said.
In fact, it's estimated that more than 70 per cent of hospital-acquired infections are associated with biofilms.
Scientists around the world have been struggling to design new weapons against biofilms. Now, Canadian researchers think they've found a way of breaking through a biofilm's protective coating, using enzymes.
Powell, who was part of the team working on the new approach, says the enzymes help to "bust up" a biofilm's shell, or matrix, creating holes that allow antibiotics or the immune system to kill the bacteria or fungi.
What's more, the enzyme technology can also prevent biofilms from forming at all.
"This is the first time we have taken a big step forward in getting a new therapy based on something that we didn't know existed five years ago," says Sheppard.
Sheppard and Howell's team conducted their research over four years, focusing on two of the most common organisms responsible for serious lung infections: a bacterium called Pseudomonas aeruginosa and a fungus called aspergillus fumigatus.
They discovered that enzymes called glycoside hydrolases could eat through all the sugar molecules that glue biofilms together.
Results of their research are available in Proceedings of the National Academy of Sciences.
Researchers are now beginning to test the enzymes in animals before beginning testing in patients.
With a report from CTV medical specialist Avis Favaro and producer Elizabeth St. Philip