Platypus milk: How it could combat super bugs

Platypus milk could help combat one of humanities looming problems, antibiotic resistance, scientists say.

Australian scientists discovered in 2010 that the semi-aquatic animals milk contains a protein able to fight superbugs. They have now been able to identify why and say it could lead to the creation of a new type of antibiotic. Platypus are monotremes - a tiny group of mammals able to both lay eggs and produce milk. They don't have teats, instead they concentrate milk to their belly and feed their young by sweating it out.

This feeding system is thought to be linked to its antibacterial properties, according to the scientists.

"Platypus are such weird animals that it would make sense for them to have weird biochemistry," Dr Janet Newman, from Australia's national science agency CSIRO, said.

It's believed mammals evolved teats or nipples because it was a sterile way to deliver milk to their young. But platypus milk being exposed to the outside leaves their babies in danger of being in contact with harmful bacteria.

The unique antibacterial protein their milk contains might be the animal's defence against that, Deakin University's Dr Julie Sharp believes.

"We were interested to examine the protein's structure and characteristics to find out exactly what part of the protein was doing what," she said.

The researchers found a quirk they say has never been seen in more than 100,000 different protein structures known to biologists.

Dr Newman said the find will "go on to inform other drug discovery work".