Metal complexes can be used as antimicrobials

European scientists have found that novel classes of compounds, such as metal complexes, can be used as alternatives to or to supplement traditional antibiotics, which have become ineffective due to antimicrobial resistance. Their research into these novel antimicrobials has been published in the journal PLOS ONE.

Antimicrobial resistance is a growing threat, with 700,000 people around the world each year dying due to drug-resistant infections including tuberculosis, HIV and malaria. A review of antimicrobial resistance has predicted that if no action is taken, drug-resistant infections will kill 10 million people a year by 2050.

Now, researchers from the Universities of Surrey, Sheffield and Würzburg have discovered that the antibacterial activity of the licensed antibiotic colistin is significantly enhanced when used in combination with a novel tryptophan manganese(I) carbonyl complex (Trypto-CORM) against Neisseria gonorrohoeae, which in recent years has shown increasing antibiotic resistance. The combination was said to be far more effective in killing multidrug-resistant bacteria than colistin alone.

The activity was also confirmed in an insect model of infection, where survival rates of 87% were observed in those treated with the combination. In comparison, the rate of survival for those given colistin alone was just 50%.

“Antimicrobial resistance is a constant threat, as bacteria continue to evolve at a rapid pace,” said lead author Dr Jonathan Betts, from the University of Surrey. “This makes it very difficult for us to treat bacterial diseases, as many antibiotics are becoming redundant, limiting the treatments available to people and animals.

“However, by combining these drugs, in our case with a novel metal complex, we could extend their lifespan and effectiveness, helping us tackle this growing threat. Antibiotics which are no longer effective could potentially be reactivated when used with this compound, providing medical professionals greater options in treating diseases.”