Komodo dragons inhabit small islands in Indonesia and are currently the largest living lizards. They feed on smaller animals with the help of their toxic saliva, thought to contain over 50 species of bacterial pathogens. The dragons exhibit immunity to wounds inflicted by other dragons that would have been lethal towards animals without an innate immune resistance to such bacteria.
Barney Bishop, Monique van Hoek, and scientists at George Mason university have begun conducting research on identifying exactly what constitutes the antibacterial activity of Komodo dragon blood.
The team employed a technique known as bioprospecting where samples of Komodo dragon blood were mixed with a negative hydrogel that separated the positively charged peptides they believed were responsible for the antibacterial resistance. By combining peptide sequencing with transcriptome assembly, they identified 48 cationic antimicrobial peptides (CAMPs) from the Komodo dragon that could potentially have antimicrobial properties.
They tested the proteins with Pseudomonas aeruginosa and Staphylococcus aureus, two bacterial strains known for their antibiotic resistance and serious effects on human health. 7 of the 48 CAMPs showed effectiveness against both of the microbes.
These findings demonstrate evidence that histone-derived proteins are essential to fighting pathogens. However, the study has not provided information regarding the mechanism by which the histone-derived antimicrobial peptides are created or how they prevent infection.
Further studies will attempt to identify the origin of such proteins in Komodo dragons. Identifying whether the proteins exist as an innate part of the immune system or are created as a response to pathogen detection will allow scientists to better understand the activity of CAMPs in fighting pathogens in Komodo dragons, other animals, and possibly humans.
Sources: Antimicrobial substances identified in Komodo dragon blood. ACS News Service Weekly PressPac. February 22, 2017.