Quirks & Quarks

Viruses that kill superbugs could save lives when antibiotics don't work

Antibiotic resistant bacteria could be treated with the viruses that attack them in nature, which are harmless to humans.

Antibiotic resistant bacteria could be treated with the viruses that attack them in nature

Dr. Benjamin Chan supplied the phages that saved Paige Rogers' life, when the Pseudomonas bacteria in her lungs became antibiotic resistant. (Paige Rogers)

Fighting terrible and potentially lethal bacterial infections with viruses may sound like a bad idea, but it may just be the best strategy we have for battling antibiotic resistant infections in patients who have little other hope.

Phage therapy, the use of bacteria-killing viruses called bacteriophages against superbugs that no longer respond to antibiotics, is currently a last-resort, experimental therapy available only to those for whom traditional treatments aren't working. But the success of these experimental treatments is providing evidence that could open the door to larger clinical trials which could prove the efficacy and safety of phage therapy. 

The superbug crisis

"Superbugs are very dangerous," said Jonathan Dennis, a phage therapy researcher at the University of Alberta. "These bacteria have been exposed to high levels of antibiotics and have developed resistance mechanisms against them."

The overuse of antibiotics in the past few decades has led to the antimicrobial resistance crisis. Antimicrobial resistance has been increasing year by year, and scientists estimate that approximately 10 million people could die every year as a result of antimicrobial resistance by 2050.

An electron micrograph showing one type of bacteriophage used in phage therapy. Scale bar is equal to 100 nm. (Jonathan Dennis)

"At some point, we're going to have to discover alternatives to the current antibiotics we have, whether that's discovering new classes of antibiotics, or developing completely new therapies such as bacteriophage therapy," said Dennis.

Bacteriophages were discovered around 1915, and there was a short burst of interest in using them to fight disease. But research on them was later abandoned in Western medicine once antibiotics were discovered.

However, in the last decade or so, with concerns about superbugs on the rise, there's been new research interest in bacteriophages in North America and Western Europe. 

Paige's story

Paige Rogers lives in Lubbock, Texas. Since the age of two, she's spent a good part of her life in the hospital.

Paige Rogers at the hospital after receiving phage therapy. (Paige Rogers)

The 23-year-old was born with cystic fibrosis, a genetic disorder that causes her lungs to fill with thick mucus. This creates the perfect conditions for bacteria to grow, and she's suffered from chronic lung infections with a bacteria called Pseudomonas that antibiotic treatments controlled, but could never wipe out completely.

In 2015, the bacteria had flared up again in her lungs. She did her regular two week round of antibiotics, but there was no improvement. The Pseudomonas bacteria had evolved antibiotic resistance, and the powerful intravenous antibiotics she depended on for most of her life could no longer effectively fight her infection.

Rogers was facing a very dangerous situation. Desperate, her father searched online for a way to save his daughter and stumbled upon phage therapy.

Bacteriophages, or phages for short, are viruses that have evolved to attack specific strains of bacteria cell. They are the most numerous biological entity on Earth, and can be found everywhere including the soil, on our skin, on animals and plants. They've coexisted with bacterial cells for billions of years — long before animals appeared.

Treating bacterial infections with phages is still considered an experimental therapy in the United States and Canada. 

Rogers was hesitant to try it at first. But with few options left, she agreed.

A magnified petri dish showing active phages clearing patches of bacteria on a lawn of bacterial growth at Dr. Jonathan Dennis's lab. (Jonathan Dennis )

After several rounds of phage treatments, she started to feel better. Her pulmonary function improved and she was more energetic.

"Now that the phages have started working, I have had way more energy. I can actually take trips, go places on weekends, I can work more and actually have a day without having to have a nap," said Rogers. "I can just do simple things most people are used to doing and I never got to. I feel like the future is only going to get brighter and brighter because the phages are actually helping me live a better life."

The demand for phage therapy

Dr. Benjamin Chan is a phage researcher at Yale University and the doctor who supplied the phages that appear to have worked well for Rogers.

He's one of a handful of researchers in the United States treating patients using phages and investigating whether phage therapy can be practical in the wider population.

Dr. Benjamin Chan sampling bacteriophages in the water in Haiti to add to his phage library, so he'll have the right viruses on hand to help fight a patient's infection. (Benjamin Chan)

"We've treated seven patients so far and an eighth one is very near," said Chan. "I get a lot of inquiries about phage therapy everyday, so we've got a pretty big and growing list of people that are interested in doing this just because antibiotic resistance is a big problem."

Push backs and safety concerns

Chan's work has met with some skepticism from the medical community, but he thinks that could change if larger scale clinical trials show that phage treatment is as effective and safe as these experimental treatments suggest. 

"We're getting with these one off cases — seven so far — some really encouraging data," he said. "It looks like we're having a real impact on these infections, so I think when we show people strong data, they will slowly get convinced that this is something that could be a really useful tool in treating these infections."

Safety is a significant public concern with phages, as they're viruses. But Chan explained that they can't infect humans because phages only target specific bacteria strains. Safety studies, so far, haven't shown any major problems. 

Phage research in Canada

In Canada, Jonathan Dennis is one of only six scientists conducting phage research, and the only one to focus on phage therapy.

He's been building a catalogue of different phages that work against specific strains of antibiotic resistant bacteria so he'll have the right viruses on hand to help fight any patient's specific infection.

Lab personnel working in the laboratory of Dr. Jonathan Dennis at the University of Alberta. (Jonathan Dennis)

He has worked with clinicians in the U.S. to treat a few patients on an experimental basis, and may be providing phages for an experimental treatment on a Canadian patient soon. 

That would be an important step, but he says that compared to the U.S. and Europe, the speed of research is much slower in Canada due to the lack of funding for phage research, which has forced many Canadian scientists who were interested in phage therapy to move on to new research topics.   

Going mainstream

There's still a long road of further investigation before phage therapy can become mainstream, but both Chan and Dennis are optimistic. 

"It'll just take a bit more work," said Chan. "We'll just have to get these phages through clinical trials and show that they are actually doing what we think they're doing."

"I think as antimicrobial resistance increases over time, more people will realize that phage therapy is our best option for treating bacterial infections other than chemical antibiotics," said Dennis, "and more money will be funneled into funding phage therapy and phage biology research."