Star weapons the key to killing superbugs Tuesday, 13 September 2016

Australian engineers may have come up with a new method for killing antibiotic-resistant bacteria (also known as superbugs).

The team from the University of Melbourne created tiny star-shaped molecules called ‘peptide polymers’ which are extremely effective at killing Gram-negative bacteria – a major class of bacteria known to be highly prone to antibiotic resistance – while being non-toxic to the body.

Professor Greg Qiao from the Department of Chemical and Biomolecular Engineering said that currently the only treatment for infections caused by bacteria is antibiotics. However, over time bacteria mutate to protect themselves against antibiotics, making treatment no longer effective.

“It is estimated that the rise of superbugs will cause up to ten million deaths a year by 2050. In addition, there have only been one or two new antibiotics developed in the last 30 years,” Qiao said.

His team has been working with peptide polymers for the past few years. He said they are also effective in killing superbugs when tested in animal models and, so far, the superbugs have shown no signs of resistance against the peptide polymers.

The team discovered that their star-shaped peptide polymers can kill bacteria with multiple pathways, unlike most antibiotics which kill with a single pathway.

They believe that this accounts for the superior performance of the star-shaped peptide polymers over antibiotics. One of these pathways includes ‘ripping apart’ the bacteria cell wall. (see image).

Qiao said other tests undertaken on red blood cells showed that the star-shaped polymer dosage rate would need to be increased by a factor of greater than 100 to become toxic.

While more research is needed, Professor Qiao and his team believe that their discovery is the beginning of unlocking a new treatment for antibiotic-resistant pathogens.

[Images of bacteria cell walls before (left) treatment with the star-shaped polymers and after (right). Photos: University of Melbourne]