Komodo dragons, the world’s largest lizards, are not animals you’d want to meet in a dark alleyway—or anywhere else, for that matter. They grow up to 10 feet long, and, although they have weaker jaws than house cats, they kill whatever they’re going to eat by biting them with sharp teeth that inject venom that stops blood from clotting. Additionally, though, these bites contaminate prey with whatever other potentially harmful bacteria are in the dragon’s mouth.
You’d think Komodo dragons would also get sick biting each other—which large lizards are wont to do—but they don’t.
The answer could be their blood. Researchers from the George Mason University in Virginia found 48 separate protein-like compounds in the blood of Komodo dragons that ward off bacteria. In lab tests, eight of these were able to fight off strains of bacteria that frequently cause drug-resistant hospital infections, suggesting that Komodo dragon’s blood could be a source of inspiration for future antibiotics for people. Their work was published (paywall) in February in The Journal of Proteome Research.
Most animals (including us) have compounds, called cationic antimicrobial peptides, floating around in our blood as part of our immune system. Even when we don’t feel sick, these compounds are beating back potentially harmful microbes. When we do fall ill as a result of a bacteria, we need extra help from antibiotics. But since we started using antibiotics like penicillin around the 1930s, bacteria have evolved to develop new tricks to thrive despite them. Now, the World Health Organization considers 12 of these so-called superbugs to be major threats to human health. Scientists are looking everywhere for alternative treatments.
Because of Komodo dragons’ apparent resistance to their own poisonous bacteria, scientists thought they may be a good source of inspiration. The team identified the dragon’s antimicrobial peptides, and then isolated eight that looked like they’d be able to fight pathogens that make people sick. They exposed these eight chemicals to two types of bacteria, Pseudomonas aeruginosa and Staphylococcus aureus, both of which can cause resistant infections and are on the WHO’s list. In seven cases, the peptides killed off large portions of both types of bacteria; the eighth could only kill P. aeruginosa.
Scientists still need to figure out how to make antibiotics from these compounds, but the fact that they’ve been able to keep dragons alive suggest they may be worth the work.