Scientists find plasmids may be key to antibiotic resistance

Scientists find plasmids may be key to antibiotic resistance

Scientists may have found one of the key routes that bacteria use to transfer antibiotic resistance to each other, a breakthrough that could have a significant and positive effect on healthcare around the world.

A team at the University of Montreal knew that one of the ways in which antibiotic resistance spreads in hospitals is via genes coded on bacterial plasmids - fragments of DNA that carry information useful for the microbes.

They used X-ray crystallography to screen a library of small chemical molecules, looking specifically for those that bind to a protein called TRaE. This is a vital component of the plasmid transfer machinery.

In doing this, the team was able to locate the exact binding site of the molecules with the TraE. Once they had done this, they could design more potent binding molecules that blocked the transfer of the antibiotic-resistant gene-carrying plasmids.

Writing in the journal Scientific Reports, lead study author Christian Baron said he hopes the strategy can be used to develop more inhibitors of the transfer of resistant genes.

"Other plasmids have similar proteins, some have different proteins, but I think the value of our study on TraE is that by knowing the molecular structure of these proteins we can devise methods to inhibit their function," he commented.

The team is now working with medicinal chemists to develop the molecules into inhibitors that could one day be applied in hospitals that have problems with antibiotic resistance.

Antibiotic resistance is one of the most significant issues in medicine that the world faces today, with England's chief medical officer Dame Sally Davies calling it "an antibiotic apocalypse".

Currently, around 700,000 people a year die worldwide from drug-resistant infections, but this figure could reach ten million by 2050.

Eventually, routine surgery, joint replacements, Caesarean sections and chemotherapy could all be at risk, with common infections having the potential to kill again as they did hundreds of years ago.