Researchers have identified a virus that is capable of “spying” on the molecular communications between bacteria – and now they've weaponized the ability so that the virus kills bacteria on command. This approach has been used by researchers to attack bacterial diseases like salmonella, cholera, and E. coli.

The work, published in the journal Cell, was conducted by Professor Bonnie Bassler and graduate student Justin Silpe from Princeton University. They discovered that the virus VP882 eavesdrops to make a binary choice: stay put or kill its bacterial host. Kill only happens if the virus knows that the bacteria is not alone, so that it can safely destroy the bacteria and move on to the next target.

“The idea that a virus is detecting a molecule that bacteria use for communication – that is brand-new,” explained Bassler in a statement. “Justin found this first naturally occurring case, and then he re-engineered that virus so that he can provide any sensory input he chooses, rather than the communication molecule, and then the virus kills on demand.”

Years ago, Bassler had discovered that bacteria can communicate using chemical signals to detect each other. These molecular messages serve to establish a quorum before bacteria act in unison. The discovery of a quorum-sensing virus was shocking.

“The bugs are getting bugged,” Bassler laughingly stated. “Plus, Justin’s work shows that these quorum-sensing molecules are conveying information across kingdom boundaries. They may not all be listening in to this quorum-sensing information, but it is clear that these viruses can listen in to their hosts’ information and then use that information to kill them.”

VP882 is the first known virus to use this trans-kingdom communication as an activation strategy. This could potentially be a great weapon in the fight against antibiotic resistance. The team just had to experiment on the virus until they found a way to communicate a “kill” order, which they then demonstrated in various pathogenic bacteria.

“Communication seems like such an evolved trait,” Silpe commented. “It was just mind-blowing that organisms you think of as so primitive could actually be capable of communication. And viruses are even simpler than bacteria. The one I studied, for example, only has about 70 genes. It’s really remarkable that it devotes one of those genes to quorum sensing. Communication is clearly not something higher organisms created.”

The team believes there are many viruses that act like VP882 and that this is the beginning of a whole new field.