Photo: flickr/Chen Wu
When it comes to finding novel chemical compounds that act as antibiotics, scientists have to look in increasingly unusual places. Like sloth hair. And now, according to this study, Tasmanian devil milk. Apparently, this milk contains a class of antimicrobial peptides called "cathelicidins" that can even kill the dreaded superbug MRSA. Tasmanian devil milkshake, anyone?
Cathelicidins in the Tasmanian devil (Sarcophilus harrisii) "Tasmanian devil joeys, like other marsupials, are born at a very early stage of development, prior to the development of their adaptive immune system, yet survive in a pathogen-laden pouch and burrow. Antimicrobial peptides, called cathelicidins, which provide innate immune protection during early life, are expressed in the pouch lining, skin and milk of devil dams. These peptides are active against pathogens identified in the pouch microbiome. Of the six characterised cathelicidins, Saha-CATH5 and 6 have broad-spectrum antibacterial activity and are capable of killing problematic human pathogens including methicillin-resistant S. aureus and vancomycin-resistant E. faecalis, while Saha-CATH3 is active against fungi. Saha-CATH5 and 6 were toxic to human A549 cells at 500 μg/mL, which is over seven times the concentration required to kill pathogens. The remaining devil cathelicidins were not active against tested bacterial or fungal strains, but are widely expressed throughout the body, such as in immune tissues, in digestive, respiratory and reproductive tracts, and in the milk and pouch, which indicates that they are likely also important components of the devil immune system. Our results suggest cathelicidins play a role in protecting naive young during pouch life by passive immune transfer in the milk and may modulate pouch microbe populations to reduce potential pathogens." Related content: Flashback Friday: Could the next all-natural insect repellent be made out of earwax?Sloth hair: source of the new wonder drug?Drinking too much milk could kill you.