Throughout the course of history, countless rivalries, varying in size, duration, and intensity, have been developed and resolved. But one of the oldest and most intense is the evolutionary-spurred conflict between bacteria and bacteriophages (or phages, which are viruses that target bacteria). Despite the longevity of this biological relationship (and because of it), scientists are continuing to discover the mechanisms bacteria use to defend themselves from phage attacks, and those that have evolved in phages to overcome bacterial defenses. It was in the course of studying this interplay that Dr. Rotem Sorek and his colleagues discovered recently a mechanism by which viruses can communicate.
Originally designed as a study of the communication mechanism used by a certain type of bacteria, known as B. subtilis, Dr. Sorek and his team wanted to put the bacteria in conflict with viruses to try to pin down exactly how the bacteria communicate. As you may know, bacteria can, in certain situations, coordinate their gene expression according to the number of other local bacteria. So, Dr. Sorek and his team put B. subtilis bacteria and a virus called phi3T together in a flask, and, as expected, the viruses killed the bacteria.
Then, to see if any signaling had taken place on a molecular level, Dr. Sorek removed the viruses and bacteria from the mixture and added the remaining mixture to a new batch of B. subtilis. Here’s where it gets interesting – when more phi3T viruses were added to this new mixture with the bacteria, the viruses changed how they attacked the bacteria; opting to inject their genomes into the bacteria and wait for signs to multiply rather than hijacking the cellular machinery immediately and killing the bacterial population. This means that the viruses were communicating. Upon further research, Dr. Sorek and his team have been able to identify just how.
It turns out, according to the study, the phages are able to communicate via a protein that was released during the first interaction between the bacteria and viruses. It seems the protein was able to instruct the viruses on the wisest course of action to extend their survival. This protein has been identified, and named arbitrium. What’s more, scientists believe there are many more types of these proteins that viruses can use to communicate. For researchers and drug makers, these findings have presented an exciting new mechanism of which antivirals can take advantage. While rivalries can have tragic consequences, here’s one humanity just may continue to benefit from.