Canadian scientists have discovered a possible way to break through the defences of some antibiotic-resistant respiratory infections.
It’s hoped that the findings could someday benefit people with cystic fibrosis and other chronic lung diseases who are at greater risk of infections.
The research looked at biofilms — slimy coatings used by some bacteria and fungi as protection.
Biofilms can be harmless, like the goop that forms on water pipes, but they are also one of the main causes of hospital-acquired infections.
Microbes form biofilms on surfaces like the insides of our lungs, heart valves and artificial hips. In fact, implanted medical devices could account for up to 70 per cent of hospital-related infections, according to previous research.
For doctors and scientists, biofilms have been a tough nut to crack. That’s because some bacteria and fungi secrete a matrix of sugar molecules to form the biofilm armour — a physical and chemical barrier to keep antibiotics and our immune cells out so they don’t have a chance to kill the pathogens.
That’s where Dr. Don Sheppard and Prof. Lynne Howell’s collaboration comes in.
Think of how humans shifted from life as hunter gatherers to building up walls around their town to protect themselves from invaders, said Sheppard, a clinician-scientist at the Research Institute at McGill University Health Centre in Montreal.
Some bacteria and fungi build a biofilm matrix, a type of city wall to defend their communities.
Sheppard and Howell were the lead authors of a study published in the journal of the Proceedings of the National Academy of Sciences in June.
They focused on two microbes that are responsible for lung infections: Aspergillus fungi and Pseudomonas aeruginosa bacteria.
In test tube experiments, the researchers discovered that the microbes use enzyme “saws” to cut and then build the walls of their biofilm homes out of uniform pieces, like two-by-four pieces of lumber.
They were able to turn the microbe’s defence against itself, using its machinery to engineer the enzymes and control where the cuts were made.
Instead of small, uniform wooden boards, the biofilms were cut into the equivalent of 10-foot-long pieces. The microbes weren’t able to use those unwieldy pieces to repair the gaping holes scientists inflicted on the biofilm walls.
“We made the uncontrolled…