Abstract

Bacteria communicate with one another via the production and detection of secreted signal molecules called autoinducers. This cell-to-cell communication process, called “Quorum Sensing”, allows bacteria to synchronize behavior on a population-wide scale. We showed that behaviors controlled by quorum sensing are ones that are unproductive when undertaken by an individual bacterium acting alone but become effective when undertaken in unison by the group. For example, quorum sensing controls virulence factor production and biofilm formation. We found that eukaryotes that harbor quorum-sensing bacteria participate in these chemical conversations by providing the substrates bacteria need to make autoinducers. We also discovered that quorum-sensing autoinducer information can be hijacked by viruses that infect and kill bacteria. Thus, interactions across the eukaryotic, bacterial, and viral domains all rely on quorum sensing. Presumably, each entity in these combined beneficial and parasitic partnerships is garnering the information encoded in quorum-sensing autoinducers to optimize its survival and reproduction. Using what we have learned, we have built quorum-sensing disruption strategies for development into new anti-microbials. We have also engineered viruses to respond to user-defined inputs, rather than the bacterial autoinducers, to make phage therapies that kill particular bacterial pathogens on demand.