Supercharged antibiotics to tackle superbugs

New approaches are needed to tackle the huge issue of antimicrobial resistance, and one option is to modify existing antibiotics to make them more effective.

Antibiotics are an essential part of modern medicine but their effectiveness has been waning in the last few decades. Certain bacteria, so called superbugs, have become resistant to multiple common antibiotics, leading to the UN declaring that antimicrobial resistance is one of the top 10 global public health threats facing humanity.

Researchers at Monash University and Harvard University, including lead author Jennifer Payne, have developed a way of boosting the effectiveness of antibodies by guiding the body’s immune system to the site of infection. This is achieved by attaching a new molecule onto existing antibiotics, thus enabling a two-pronged approach.

Classical antibiotics work by attacking the harmful bacteria but this enhanced antibiotic has a small molecule called a chemoattractant attached to it, which is able to guide the body’s white blood cells to the site of infection, acting like a ‘guiding light’. Therefore it enables the bacteria to killed by a combination of the antibiotic and the body’s immune response.

This is important because superbugs are known to not only be resistant to existing antibiotics but also be extremely capable at hiding from the immune system, thus preventing it from responding to the infection. This new combined drug ensures that the immune system can locate the superbug, meaning it can then eliminate it, as it does with most harmful bacteria it encounters. 

Research into antibiotics has hit a standstill in recent years. “In the last 20 years, there have been no new novel antibiotics reaching our pharmacy shelves,” says Payne. She goes on to say that researchers have not gone beyond the conventional methods of finding new antibiotics, for example by looking for them in soils. Payne’s work steps away from that.

The importance of their work is paramount. According to Payne, without effective antibodies "we are going to be...plunged back into the Dark Ages.” This would mean simple surgeries might be too risky to perform given the risk of a super bacterial infection. Furthermore antimicrobial resistance could lead to up to 10 million deaths per year (twice the death toll of the COVID pandemic) by the year 2030.

Payne and her colleagues performed this study by chemically bonding an existing antibiotic with a chemoattractant attached to it, and then testing its effectiveness in both humans and mice.

This new supercharged antibiotic was found to be highly effective in eliminating superbugs. In human immune cells, it was found to significantly improve the immune system's ability to annihilate superbugs. In the mice trials, where mice were given a type of superbug pneumonia, the new antibiotic was able to halve the amount of bacteria in the lungs compared to the typical antibiotic treatment.

However, Payne notes that future work is still needed to ensure there are no side effects to this treatment and that the immune system is localised to the site of infection.

In any case, due to customisability of the approach, this preliminary study opens up a whole new avenue for antibiotics research where different molecules can be combined together to address particular superbugs or made to work with particular existing antibiotics.

We can also help to do our part in reducing the prevalence of superbugs by taking care of our personal hygiene, not asking for antibiotics when you have a viral infection and also supporting farmers who do not use antibiotics unnecessarily on the animals they raise.