Metals could be link to new antibiotics

Photo: Centre for Superbug Solutions, Institute for Molecular Bioscience, University of Queensland.

Compounds containing metals could hold the key to the next generation of antibiotics to combat the growing threat of global antibiotic resistance, according to University of Queensland researchers (UQ).

“This is promising research because the scientific community is struggling to keep up with the pace of bacterial resistance,” Dr Mark Blaskovich said.

“There are around 40 new antibiotics in clinical trials, which sounds encouraging until you compare this to the more than 1000 medicines and vaccines in clinical trials for cancer treatments.”

The research team was led by Dr Mark Blaskovich, Dr Angelo Frei and Dr Johannes Zuegg at UQ’s Centre for Superbug Solutions at the Institute for Molecular Bioscience, working with a network of international collaborators.

Their research team has discovered 23 previously unexplored compounds containing metals such as silver, manganese, zinc, ruthenium and iridium that have antibacterial and antifungal activity. They found that many of the compounds selectively kill bacteria cells, but not human cells.

“Finding completely new types of antibiotics in these metal-containing compounds offers promise to outwit bacterial resistance, because they likely use different mechanisms which the bacteria have not encountered previously,” Frei said.

Almost 75 per cent of the antimicrobial medicines under development were derivatives of known and used antibiotics, making them potentially susceptible to existing bacterial resistance.

“We embarked on a quest to tap into the millions of compounds sitting unused on laboratory shelves, discarded because they don’t fit the mould for common drug design,” Blaskovich said.

“We test these compounds to see if they have an effect on bacterial and fungal pathogens. So far we have received and screened 300,000 compounds, including nearly 1000 metal-containing compounds, from over 300 academic groups across 47 countries.”

The research team hopes the findings will bring prompt new investment in antimicrobial research.

“Many pharmaceutical companies are bowing out of antibiotic research as there is little return on investment,” Frei said.

“So it is vital to raise awareness that metal complexes are a prospective source of truly novel antibiotics with potential for combatting antimicrobial resistance.”