Super antibiotics hidden in the wallaby genome

Wallaby pouches aren’t the most hygienic of places. They’re haven to not only the wallaby’s tiny young, but also to a host of microbes, some of which resemble the ‘superbugs’ cropping up in hospitals around the world.

Meanwhile, wallabies are born without an adaptive immunity, meaning they can’t produce antibodies until they’re around 100 days old. Yet they’re able to resist infection from the pouch microbes.

It’s in uncovering the mechanisms behind this curious phenomenon that researchers like Professor Ben Cocks from the Animal Genetics and Genomics at La Trobe University hope they can find new agents that might be effective against the growing number of fierce multi-resistance bacteria.

Professor Cocks and his team dug into the recently published wallaby genome in the hope of uncovering some of the tricks that wallabies have to fight infection, and they struck gold with some genes that appear to date back around 60 million years.

They found a number of genes that code for 14 peptides that appear to help protect the newborn infant marsupials against infection while residing in the pouch.

They then used bioinformatics modelling to work backwards and recreate the ancestral marsupial gene that codes for these peptides, which might be developed into new antibiotic treatments to combat the so-called ‘superbugs.’

One of the peptides they’re interested in exists in the highly rich wallaby milk in the early stages of lactation. According to Cocks it is “very potent against multi-drug-resistant bacteria and, in fact, up to ten times more potent than drugs like tetracycline and ampicillin.”

“We've actually tested the clinical isolates from Australian and American hospitals, which are actually resistant to all available antibiotics, and the peptides were very effective against those particular bacteria,” he said in a La Trobe podcast.

His team has also identified eight candidate genes in platypus. “Marsupial and monotreme young are protected by antimicrobial peptides that are potent, broad spectrum and salt resistant. Hence the genomes of our distant relatives may hold the key for the development of novel drugs to combat multidrug-resistant pathogens,” he said.

Cocks and his team collaborated with Associate Professor Kathy Belov at the University of Sydney, who also works with marsupials, such as the platypus.

“At the moment we're actually working on some of the modern-day peptides, as they appear to be very effective,” he said. “And then incorporating some of the advantages of some of the computationally predicted peptides in proving what we have as potential therapies.”

The paper was published in the journal PLoS ONE.