University of Adelaide researchers teamed up with Professor John Moses from New York's Cold Spring Harbor Laboratory for the study.

Prof Moses and his team used "click chemistry" to modify the antibiotic vancomycin, often used as a last resort for serious bacterial infections.

They connected two molecules of vancomycin with a flexible, shape-shifting core, meaning the new molecules could adapt how they interact with bacteria.

"(We) then tested these molecules and showed they were a stronger antibiotic that was able to kill bacteria that was initially resistant to vancomycin," co-author Jessica Wyllie from the University of Adelaide said.

"We found the bacteria were less likely to develop resistance to those molecules, so we should be able to use this antibiotic for longer to treat bacterial infections."

Antimicrobial resistance, including drug-resistant bacteria, is believed to be responsible for hundreds of deaths a year in Australia.

Drug-resistant bacteria are predicted to cause more than 10 million deaths per year worldwide by 2050, with the World Health Organisation declaring the problem a major public health threat.

"We have all been prescribed an antibiotic at some time in our lives, whether it be to treat a sinus infection or a skin infection," co-author Dr Tatiana Soares da Costa from the University of Adelaide said.

"The problem is overuse of antibiotics has allowed bacteria to develop resistance to the effects of our current antibiotics.

"If we don't act now, we will soon run out of antibiotic options to treat even the simplest infections."

Researchers say although re-engineering has been a longstanding approach to developing new antibiotics, it is the first time a shape-shifting core has been used.

It marked a major step forward in the battle against superbugs, they said.

"This study shows re-engineering our current arsenal of antibiotics is a viable approach to fast track the development of better antibiotics to the market," Dr Soares da Costa said.

The study was published in the journal Proceedings of the National Academy of Sciences.

Australian Associated Press