Bonnie Bassler has managed to eavesdrop on the ‘conversations’ bacteria hold with one another that enable them to act cooperatively, as if part of a single organism. By decoding the chemical signals that bacteria exchange, she has been able to suggest alternatives to conventional antibiotics that might avoid the problem of resistance.

The phenomenon Bonnie studies, called quorum sensing, tells bacteria whether they are alone or in a crowd. Both harmless and pathogenic bacteria use this system to coordinate activities such as bioluminescence or virulence that are effective only when they act as a group.

Bonnie discovered a signalling molecule called autoinducer-2 (AI-2) that serves as a ‘common language’ used by several species. Her group is working to develop molecules similar to AI-2 that might ‘deafen’ dangerous pathogens and so function as antimicrobial agents. This idea led to her being selected as a MacArthur Fellow in 2002, citing her extraordinary creativity.