Scientists unlock frogs’ antibacterial secrets to combat superbugs
The lab of César de la Fuente has created synthetic peptides, a class of antibiotics, derived from the secretions of a frog commonly found in South Asia.
2 min. read
Frogs have evolved and thrived for hundreds of millions of years, developing remarkable defenses—including previously unreported antibiotics—against the hordes of bacteria that thrive in their moist environments.
The researchers extracted a peptide from Odorrana andersonii, a frog found in South Asia, and used it to derive new antibiotics.
(Image: De la Fuente Lab)
The paper builds on previous work from de la Fuente’s lab, which has discovered novel antibiotics in a range of unlikely places: the DNA of extinct organisms, including the wooly mammoth; the DNA of Neanderthals; and the human gut microbiome.
“Each study is motivated by imagining environments where evolution would spur the creation of antibiotics,” says de la Fuente. “Amphibians live in very microbe-rich environments. They very rarely get infected despite being surrounded by microbes, so they must produce antimicrobial compounds.”
In the new paper, de la Fuente and his co-authors demonstrate how “structure-guided design,” a process involving minute changes to the peptide’s chemical structure, yields multiple antibiotic candidates without the drawbacks of the unmodified peptide.
“With structure-guided design, we change the sequence of the molecule,” says Marcelo Torres, a research associate in the de la Fuente lab and co-author of the paper, “and then we see how those mutations affect the function that we are trying to improve.”
After going through two rounds of structure-guided design, the researchers then tested the resulting synthetic peptides against a range of bacteria. In preclinical models, the team found that the new compounds were as effective as last-resort antibiotics like polymyxin B in targeting harmful bacteria, without affecting human cells or beneficial gut bacteria.
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