Killing Mechanism

When an antibiotic-resistant superbug strikes, doctors must scramble to find alternative medicines. In the case of skin and soft-tissue infections resulting from methicillin-resistant Staphylococcus aureus (MRSA) bacteria, for example, they can turn to a remaining weapon in their arsenal, daptomycin. Despite this antibiotic having been in clinical use for almost two decades, the drug’s precise mechanism of action was unclear. Now, researchers have shown that the drug (green) accumulates in the membrane of S. aureus (pictured) at the region where the new cell wall is built (the band across each newly divided cell). The drug binds two important building blocks for wall formation, preventing further construction, and eventually leading to cell death (resulting in the disordered staining pattern seen in the bottom row). By identifying these target molecules essential for daptomycin’s deadly effect, researchers may be able to design much-needed new medicines for the continuing war against antibiotic resistance.

Written by Ruth Williams

Ruth Williams

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Ruth is a freelance science journalist based in the US. She's a regular correspondent for The Scientist, and her work has appeared in The Lancet, Nature, Scientific American Mind, BBC Focus and elsewhere. Twitter @rooph

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• Image from work by Fabian Grein, Anna Müller and Katharina M. Scherer, and colleagues
• Institute for Pharmaceutical Microbiology and Institute for Physical and Theoretical Chemistry, University of Bonn, Bonn, Germany
• Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Published in Nature Communications, March 2020