Komodo Dragon Blood Could Fight Antibiotic-Resistant Bacteria

On five small islands in Indonesia, survival is precarious. Yet Komodo dragons, the world’s largest lizards, thrive despite being exposed to tons of bacteria that would kill less hardy creatures. Now, in a study published in the Journal of Proteome Research, researchers report that they have detected antimicrobial protein fragments in the lizards’ blood that appear to help them resist deadly infections. The discovery could lead to the development of new drugs capable of combating bacteria that have become resistant to antibiotics.

Komodo dragon saliva contains at least 57 species of bacteria, which are believed to contribute to the demise of the lizard’s prey. Not only does the lizard appear to be resistant to these bacteria, but Komodo dragon serum has been shown to have antibacterial activity. Compounds known as cationic antimicrobial peptides (CAMPs) are produced by nearly all living creatures and are essential parts of the innate immune system.

Barney Bishop, Monique van Hoek, and colleagues at the College of Science at George Mason University wondered whether they could isolate CAMPs from Komodo dragon blood to expand the library of known CAMPs for therapeutic studies.

The team used an approach known as bioprospecting. They incubated Komodo dragon blood with negatively-charged hydrogel particles that they developed to capture the positively-charged peptides. Using this method, they identified and sequenced 48 potential CAMPs with mass spectrometry. All but one was derived from histone proteins, which are known to have antimicrobial activities. Eight CAMPs were synthesized and tested against Pseudomonas aeruginosa and Staphylococcus aureus. Seven of the peptides showed significant potency against both bacteria. The eighth was only effective against P. aeruginosa.

The researchers conclude that Komodo dragon blood plasma contains a host of potentially viable antimicrobial peptides that could help lead to new therapeutics.

The researchers acknowledge funding from the Defense Threat Reduction Agency (DTRA).

Read more about the research: Discovery of Novel Antimicrobial Peptides from Varanus komodoensis (Komodo Dragon) by Large-Scale Analyses and De-Novo-Assisted Sequencing Using Electron-Transfer Dissociation Mass Spectrometry, J. Proteome Res., 2017, Article ASAP.