MELBOURNE, Oct. 28 (Xinhua) -- Chemists in Australia and Britain have discovered a promising new antibiotic capable of killing drug-resistant bacterial pathogens, including MRSA and VRE.
The newly discovered antibiotic, called pre-methylenomycin C lactone, was found "hiding in plain sight" as an intermediate chemical in the natural process that produces the well-known antibiotic methylenomycin A, according to a Monash University press release on Tuesday.
"Methylenomycin A was originally discovered 50 years ago and while it has been synthesized several times, no one appears to have tested the synthetic intermediates for antimicrobial activity," said study co-lead author Professor Greg Challis from Australia's Monash University and Britain's University of Warwick.
"By deleting biosynthetic genes, we discovered two previously unknown biosynthetic intermediates, both of which are much more potent antibiotics than methylenomycin A itself," said Challis who conducted the study under the Monash Warwick Alliance Combatting Emerging Superbug Threats Initiative, established in 2012.
When tested for antimicrobial activity, one of the intermediates, pre-methylenomycin C lactone, was shown to be over 100 times more active against diverse Gram-positive bacteria than the original antibiotic methylenomycin A, according to the study published in the Journal of the American Chemical Society.
Specifically, it was shown to be effective against S. aureus and E. faecium, the bacterial species behind MRSA and VRE, respectively, it said, adding this finding is especially promising for VRE, a World Health Organization (WHO) High Priority Pathogen.
"This discovery suggests a new paradigm for antibiotic discovery. By identifying and testing intermediates in the pathways to diverse natural compounds, we may find potent new antibiotics with more resilience to resistance that will aid us in the fight against AMR (antimicrobial resistance)," Challis said.
With its simple structure, potent activity, difficult-to-resist profile, and scalable synthesis, pre-methylenomycin C lactone represents a promising new candidate that could potentially help save some of the 1.1 million people worldwide who are victims of AMR every year, researchers said.
A WHO report released earlier this month showed there are "too few antibacterials in the pipeline." However, most of the "low-hanging fruit" has already been found, and limited commercial incentives deter investment in antibiotic discovery, the Monash release said. ■