Viruses could help us win the fight against antibiotic-resistant infections
A virus called ‘Muddy’ helped treat abscess-causing infection in zebrafish
Since the discovery of penicillin by Alexander Fleming in 1928, bacteria have constantly evolved new ways to resist the effects of antibiotics.
Currently more than 50,000 people die in Europe and the US every year from infections that don’t respond to conventional antibiotic treatments. If current trends continue, all of our antibiotic medicines could become ineffective within the next few decades.
One way of potentially countering this trend is to use bacteriophages – naturally occurring viruses that are capable of killing bacteria.
Now, a team of researchers from the Université de Montpellier, France, and the University of Pittsburgh, USA, have discovered that combining bacteriophages with conventional antibiotic treatments could make them even more effective at slaying bacteria.
The team decided to focus their efforts on Mycobacterium abscessus, a relative of the bacteria that cause tuberculosis and leprosy, and is resistant to many standard antibiotics. As M. abscessus is particularly dangerous to patients with cystic fibrosis, the researchers took zebrafish that had been bred to carry the key genetic mutation that causes cystic fibrosis, then infected them with M. abscessus. They then tested the ability of a number of bacteriophages to combat the infection.
First, the team screened 10,000 bacteriophages, before they found one candidate, which they named ‘Muddy’, that was capable of efficiently killing M. abscessus in a Petri dish. They then infected zebrafish with M. abscessus and monitored them for 12 days.
They found that the fish treated with Muddy had much less severe infections and were twice as likely to survive – 40 per cent of them survived compared to 20 per cent of untreated fish.
They then treated fish with a combination of Muddy and rifabutin, an antibiotic used to treat M. abscessus infection that’s similar in effectiveness to the Muddy treatment. This time the survival rate rocketed to 70 per cent and the fish suffered far fewer abscesses.
“We need clinical trials, but there will be many other questions to be answered on our way there. And zebrafish provide a very helpful tool for advancing these questions,” said Dr Graham Hatfull from the University of Pittsburgh.
“Fish treated with ‘Muddy’ had less severe infections”