Overuse of antibiotics has spawned strains of bacteria whose cell walls are impervious to the crippling blows once delivered by penicillin and its derivatives. One such so-called superbug, methicillin-resistant staphylococcus aureus, although found primarily in prisons and hospitals, has now spread beyond those confines. Despite the controlled use of the drug vancomycin, a last line of defense against MRSA, the latest threat comes from vancomycin-resistant bacteria, which mutate by deleting a key hydrogen bond that allows the drug to bind and inhibit cell wall growth, thereby mechanically weakening the bacteria. Rachel McKendry at University College London and her collaborators recently demonstrated a nanoscale cantilever system that is sensitive enough to detect the difference between the native drug-sensitive bacteria and the mutated resistant form with the missing hydrogen bond. The researchers coated silicon cantilevers with vancomycin-resistant (Lac in the schematic) and vancomycin-sensitive (AIa) bacterial cell-wall analogues, then...

You do not currently have access to this content.