Devil's milk has proved to be an unlikely weapon in the increasingly desperate global fight against superbugs. Australian researchers have discovered that peptides contained in the milk of Tasmanian devils can kill some of the most deadly bacterial and fungal infections, including golden staph.
Having scanned the devil's genome and discovered the six naturally occurring antimicrobial peptides, researchers from Sydney University set about replicating them artificially. They then tested the peptide's effectiveness at killing some of the most harmful bacteria known to humans.
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Is Tasmanian devil milk a superbug killer?
Australian researchers discover that peptides contained in the milk of Tasmanian devils can kill some of the most deadly bacterial and fungal infections. (Vision courtesy ABC News 24)
"It was really exciting," said PhD candidate Emma Peel.
Given the marsupial delivers highly under-developed young after just 21 days gestation, there was some expectation that mother's milk would play a role in the development of the joeys' immune system after birth. However Ms Peel, a biologist, said they weren't expecting to find what they did.
"We showed that these devil peptides kill multi-drug resistant bacteria, which is really cool," she said.
Among the drug resistant bacteria the devil peptides killed was golden staph, or methicillin-resistant Staphylococcus aureus. A potentially fatal bacterium carried by about 30 per cent of people in their nose or on their skin, it is mostly harmless. However if it gets into the bloodstream via a wound, it can be deadly.
The other problematic human pathogen tested was the bacteria enterococcus
, which is resistant to the mighty vancomycin antibiotic."Vancomycin is a pretty potent antibiotic and if a bug is resistant to that, then there aren't a lot of drug options available to you," Ms Peel said.
![Biologist Emma Peel with a young Tasmanian devil.](/web/20161019004258im_/http://www.smh.com.au/content/dam/images/g/s/2/a/u/m/image.related.articleLeadwide.620x349.gs29l5.png/1476690920490.jpg)
Three years in the making, the results, published in Scientific Reports, part of the Nature journal stable, could inspire the development of new drugs that would prove crucial in the global battle against the rise of the superbug.
Director-general of the World Health Organisation Margaret Chan recently described antimicrobial resistance as "a fundamental threat to human health, development and security".
![Tasmanian devil joeys build their immune system with peptides contained in mother's milk.](/web/20161019004258im_/http://www.smh.com.au/content/dam/images/g/r/x/g/m/0/image.related.articleLeadwide.620x349.gs29l5.png/1476690920490.jpg)
It is estimated that, if left unchecked, superbugs could kill more people than cancer within four decades. Results of a review of antimicrobial resistance released in London in May suggested that if left unchecked by 2050, superbugs could kill 10 million people a year.
The devil milk peptides hail from a family of antimicrobials called cathelicidins, which act as natural antibiotics. All animals have them. Devils have six varieties, while humans have just one.
![Four-month-old Tasmanian devil joeys in their mother's pouch at Devil Ark in the Barrington Tops.](/web/20161019004258im_/http://www.smh.com.au/content/dam/images/g/q/c/4/k/5/image.related.articleLeadwide.620x349.gs29l5.png/1476690920490.jpg)
Research by other scientists has previously established marsupials carry a diverse number of these peptides: opossums have 12 and the tammar wallaby carries eight.
The antimicrobial peptides assist marsupial joeys fight off any bacterial or fungal challenge experienced while developing in the pouch, which is a far from sterile environment.
![Geneticist Kathy Belov with a devil pup.](/web/20161019004258im_/http://www.smh.com.au/content/dam/images/g/p/2/l/k/0/image.related.articleLeadNarrow.300x0.gs29l5.png/1476690920490.jpg)
A 2015 study found there was a diverse range of bacteria living in the Tasmanian devil's pouch microbiome, an ecosystem of microorganisms including bacteria.
"There are potential pathogens present in the devil microbiome, so the fact that the under-developed young in the pouch don't get sick was a clue something interesting was going on," Ms Peel said. "That's what inspired our most recent study."
Sydney University geneticist Kathy Belov said a study was under way with koalas - with preliminary results showing similar peptides were present in koala milk.
"Australia has lots of marsupials which would have evolved to protect their joeys from different pathogens in different environments," Professor Belov said. "There has to be a treasure trove of amazing peptides out there to be discovered."