Fungus molecule shows promise against drug-resistant bacteria
The World Health Organization say a post-antibiotic era - in which common infections and minor injuries can kill - is a "very real possibility for the 21st century," emphasizing the need for strategies that can combat drug resistance. Now, a new study details the discovery of a fungus in Canadian soil that may do just that.
The research team, including Gerry Wright of the Institute for Infectious Disease Research at McMaster University in Canada, says a molecule in the fungus, known as aspergillomarasmine A (AMA), is particularly effective against New Delhi Metallo-beta-Lactamase-1 (NDM-1) - a gene that makes bacteria drug resistant.
The World Health Organization (WHO) have deemed NDM-1 a global threat to public health. It is resistant to almost all antibiotics, including carbapenems - known as "last resort" antibiotics - that are used to treat bacterial infections such as Escherichia coli and Klebsiella.
"This (NDM-1) is public enemy number one," says Wright. "It came out of nowhere, it has spread everywhere and has basically killed our last resource of antibiotics, the last pill on the shelf, used to treat serious infections."
Wright adds that this particular gene is of major concern. Not only is it targeting the last remaining drugs we have available, but it is carried by organisms that are already multi-drug resistant and that carry an array of diseases.
"It has been found not only in clinics, but in the environment - in contaminated water in South Asia - which has contributed to its spread over the globe," he explains.
The team hypothesized that if they could find a molecule that could disarm NDM-1, then already-existing antibiotics would be able to fight off infections once again.
AMA molecule 'rescues the activity of carbapenem antibiotics'
According to the researchers, NDM-1 needs zinc in order to survive. They set out to find a way to remove zinc from the gene without triggering a toxic effect, and it seems the newly discovered AMA molecule can do just that.
Researchers found that a fungus-derived molecule - called AMA - works with carbapenem antibiotics to block the activity of the NDM-1 gene that causes drug resistance in certain bacteria, such as E. coli.
To reach their findings, recently published in the journal Nature, Wright and his colleagues at McMaster University - in collaboration with researchers from the University of British Columbia in Canada and Cardiff University in the UK - infected mice with bacteria that had the NDM-1 gene.
The team the gave the mice either a combination of the AMA molecule and a carbapenem antibiotic, the antibiotic alone or AMA alone.
They found that the mice who received the combination of the AMA molecule and a carbapenem antibiotic survived, while the other mice did not, suggesting that the molecule works with the antibiotics to block the function of NDM-1.
"This [process] will solve one aspect of a daunting problem," says Wright. "AMA rescues the activity of carbapenem antibiotics, so instead of having no antibiotics, there will be some. This is a made-in-Canada solution for a global problem."
Dr. John Kelton, vice president of the Faculty of Health Sciences at McMaster University who was not involved in the study, says the teams findings offer new hope in the fight against drug resistance:
"Antibiotic resistance may be the most urgent and perplexing challenge facing health care researchers today. This research provides new hope by showing us a completely new way to approach this problem, and none too soon, given the growing risk that superbugs pose to all of us."
Medical News Today recently reported on a study, also published in Nature, which detailed another discovery that could help fight drug resistance.
The researchers of that study, including Prof. Changjang Dong of the Norwich Medical School at the University of East Anglia in the UK, discovered how the defensive barriers of drug-resistant bacteria are built, which they say could lead to the development of new drugs to which bacteria are unable to develop resistance.
Written by Honor Whiteman
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