NEW MOLECULE WHICH KILLS DRUG-  RESISTANT BACTERIA DISCOVERED!

                               Lariocidin. Credit: Clouds Hil Imaging Ltd/ Science Photo Library

Scientists have discovered a new antibiotic that kills bacteria resistant to commercial drugs that are not toxic to humans! This molecule was discovered in soil samples at a laboratory technician's garden. How was this molecule exactly discovered? How does it kill bacteria? What does this discovery mean for us? Let's find out together!

How was this molecule discovered?

Gerry Wright, a chemical biologist at McMaster University in Canada, and his colleagues were determined to find out other ways that microbes eliminate pathogens. They gathered soil samples in Petri dishes with growth medium and stored them for a year. Afterward, they exposed the microbes from these samples to E. coli. E. coli is a bacterium that infects the Gastrointestinal (GI) tract and can cause diarrhea. 

One sample, a species belonging to the genus Paenibacillus, proved to be potent in killing bacteria. This bacterial species produces a peptide that forms a lasso-shaped knot. 

How does it kill bacteria?

This peptide, named lariocidin by Wright and his colleagues, binds to the ribosome and tRNA in the target bacterium. tRNA supplies the ribosome, a peptide factory, with the amino-acid building blocks needed to construct peptides. By binding to both ribosomes and tRNA, the ribosome produces incorrect peptides, some of which could be detrimental to the target bacterium and kill it. Since lariocidin uses a different way of killing bacteria compared to other antibiotics, pathogens have not yet developed resistance to it. 

What does this discovery mean for us?

Cell studies have been conducted using lariocidin. Findings did not find any evidence of toxicity against human cells. Moreover, lariocidin has proven to slow the growth of a range of common bacterial pathogens, including many multidrug-resistant strains. Many more studies are needed to determine whether the antibiotic could be safe enough to be consumed by humans, including work on how it accumulates in the body and how it is excreted.

If this antibiotic successfully becomes a consumable drug, it would be a useful addition to our arsenal against drug-resistant bacteria. 

References

1. Mallapaty, S. (2025, March 26). New antibiotic that kills drug-resistant bacteria discovered in technician’s garden. Nature News. https://www.nature.com/articles/d41586-025-00945-z