Antibiotic resistance is one of the biggest threats to public health, yet a surprisingly simple tactic could help tackle it: alternating between three different antibiotic medicines.
The approach has so far only been tested on bacteria grown in a dish, but using this method with commonly used antibiotics killed bacteria five times more efficiently than using one drug at a time.
If trials in people give similar results, it could be used to combat antibiotic resistance by asking people to take a different drug out of three every day, says at the University of Kiel in Germany.
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Antibiotics are seen as one of the greatest developments of modern medicine, transforming potential killers like wound infections and tuberculosis into something treatable with a course of tablets.
But the potency of this group of medicines is waning because bacteria can mutate to become resistant to their effects, and new drugs aren鈥檛 being developed fast enough. There are global campaigns to try to preserve our remaining antibiotics by reducing our use of them.
Doctors already change to a different antibiotic if the bacteria causing an infection become resistant to the first drug used, typically after a few weeks. Schulenburg and his colleagues wondered whether a strategy of rapid switching from the outset would be helpful.
In 2018, the team showed that if bacteria in a dish are treated with rapid switching between three antibiotics that work through different mechanisms, the microbes than if the medicines are cycled over slower timescales of a few weeks. The experiment used levels of antibiotics that were lower than normally given to people, in order to encourage resistance to develop.
In the latest study, the researchers found that the rapid-cycling approach was even more potent if they used three closely related antibiotics from a class called beta-lactams. These are often used to treat Pseudomonas aeruginosa bacteria, which can cause wound infections and pneumonia.
Sticking with three antibiotics from the same class means it is less likely that one of them will trigger allergies or side effects, says Schulenburg. If the approach translates well to people, 鈥渨e could use available antibiotics in a more effective way鈥�, he says.
eLife
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