|The research group prepared|
two types of media to test phage
Well we took a bit of a break these past couple of weeks, but we are back for the new year! Welcome to the Prophage blog 2017! The year has actually been off to a good start, with a lot of interesting papers being published this January. This week I want to kick things off by covering a very cool 2017 study by Erez et al that described an new and interesting mechanism by which bacteriophages communicate using their bacterial hosts. This really is a well written and elegant study that I highly suggest you read. In this post, I want us to cover the highlights of the study, and then discuss what this will mean for future research endeavors.
The research group led by Erez et al began their work by testing the hypothesis that "bacteria secrete communication molecules to alert other bacteria of phage infection", but what they ended up finding was arguably much more interesting. They began their series of experiments by simply growing bacteria in liquid media with and without bacteriophages (see the figure to the right). They let the mixture sit long enough for the phages to infect their bacterial hosts for a couple of replication cycles (3 hours), and then removed all of the bacteria and phages from the liquid by filtration. At this point, if there was a signaling molecule released during the infection, it would still be in the media even though the phages and bacteria were removed. Additionally, if there was a signaling molecule released during the phage infection period, repeating an infection in that same media would result in altered growth patterns (for example, less bacteria killed when the molecule is present). As it turns out, this is exactly what they observed.