The battle against resistant bacteria can take an unexpected turn

Now the slogan is still: all resistant bacteria must die. But it might be better if we let them live, argue Danish researchers.

Every day people die from a simple inflammation. Cause? Antibiotic resistant. Many bacteria are resistant to antibiotics, which means that the drug no longer works. Antibiotic resistance has become a ticking time bomb. For example, the WHO predicts that by 2050 more people will die from an infection (which we still consider to be harmless today, such as a cut, a wound or perhaps a bladder infection) than from cancer. Many scientists are therefore looking for solutions. But perhaps that quest could now take an unexpected turn.

bacteria

Bacteria are masters of adaptation. When their existence is threatened, they simply mutate into a new and improved version of themselves. And the same is happening with the threat of antibiotic resistance. Bacteria adapt so that they can no longer be killed by antibiotics. And so today, many disease-causing bacteria have become resistant to antibiotics. “That’s just what bacteria do,” says researcher Birgitte Kallipolitis. “They always find a way. It is logical that resistance occurs, that’s how evolution works.”

The prevailing slogan

A lot of energy is currently being put into killing the bacteria that have become resistant. But Danish researchers are now arguing that we might be better off tackling the issue in a different way. They suggest it is time to find a new way to fight the constantly mutating bacteria. And not by killing the bacteria, but by ‘just’ making them harmless while they are in our body.

fatty acids

For several years now, the researchers have been studying a certain type of fatty acid that appears to be of interest in this regard. The researchers use the listeria bacterium in their experiments to test the effect of the fatty acids. The experiments show that the fatty acids have an antimicrobial effect, ie they are able to kill listeria bacteria. While that sounds promising, we’re not there yet because of the bacteria’s ability to mutate: if you try to kill the bacteria, it just turns into a new and resistant version of itself.

Harmless

But after analysis, the fatty acids turn out to have another promising potential. The experiments show that they can also render the resistant bacteria harmless, so that no infection occurs at all. In other words, the researchers succeeded in making sure that the disease-propagating bacteria can no longer spread or make someone sick. This is also known as ‘turning off its virulence’. “If you turn off the virulence of a bacterium, you prevent it from producing proteins such as adhesin and invasin; proteins that the bacterium uses to attach itself to a cell so that it can enter the cell,” explains Kallipolitis. “And if a listeria bacterium cannot enter a cell, it cannot spread and there is no infection.”

Exposure

There is, however, a caveat. The listeria bacteria in the researchers’ experiments are only harmless as long as their virulence is switched off. When they are no longer exposed to the fatty acids that do that, they regain the ability to proliferate. “However, this could be the extra help that allows a patient to overcome the infection,” Kallipolitis said.

Next step

The next step will be to test the antivirulence effect in a lab system that mimics the human gut. “We’ll add listeria bacteria to this and see if the fatty acids make them avirulent,” Kallipolitis said. “If this works, we will switch to experiments with mice. And eventually hopefully it can be used in humans.”

The findings – which have been published in two scientific papers, here and here read – point out that it may be time to rethink the fight against antibiotic resistance. The resistant bacteria may no longer be a bacteria that we should try to kill, but we may be able to save more lives if we let it live. “Then we prevent it from spreading and making us sick,” Kallipolitis sums up. And maybe that’s the way to success.