Antibiotic with no resistance discovered

Researchers from Northeastern University have discovered an antibiotic which eliminates pathogens without encountering any detectable resistance - a promising weapon in the war against superbugs such as methicillin-resistant Staphylococcus aureus (MRSA).

Writing in the journal Nature, the study authors stated, “Most antibiotics were produced by screening soil microorganisms, but this limited resource of cultivable bacteria was overmined by the 1960s. Synthetic approaches to produce antibiotics have been unable to replace this platform.” Professors Kim Lewis and Slava Epstein thus sought to tap into a new source of antibiotics: uncultured bacteria, which make up 99% of all species in external environments.

Through the creation of the iChip - a miniature device that can isolate and help grow single cells in their natural environment - Lewis and Epstein founded biotechnology company NovoBiotic Pharmaceuticals, which has gone on to assemble about 50,000 strains of uncultured bacteria and discover 25 new antibiotics. During a recent screening for antimicrobial material, the team discovered their latest antibiotic (termed teixobactin), which they said “inhibits cell wall synthesis by binding to a highly conserved motif of lipid II (precursor of peptidoglycan) and lipid III (precursor of cell wall teichoic acid)”.

The compound showed potent killing against a broad panel of bacterial pathogens - including MRSA and Mycobacterium tuberculosis - while encountering no resistance. Lewis said this marks the first discovery of an antibiotic to which resistance by mutations of pathogens have not been identified, suggesting that the compound “evolved to be free of resistance”.

“Teixobactin’s dual mode of action and binding to non-peptidic regions suggest that resistance will be very difficult to develop,” he said.

“This challenges the dogma that we’ve operated under that bacteria will always develop resistance.”

Lewis said the research lays new ground to advance his work on treating MRSA and other chronic infections, with the team hoping to eventually develop teixobactin into a drug. They concluded, “The properties of this compound suggest a path towards developing antibiotics that are likely to avoid development of resistance.”

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