Predicting Bacterial Warfare

Another week has come and passed, and delivered more news from the frontlines of microbial warfare. Although, instead of viruses and bacteria doing biological battle, a new publication in Nature Communications details how scientists pitted competing bacterial groups against each other and predicted how the conflict would unfold using previously existing physics equations.


As you’re likely aware, microbes are constantly on the hunt for free space and sources of metabolites and proteins to sustain their dense communities. Using that knowledge, Georgia Institute of Technology researchers combined two different strains of cholera bacteria and followed the subsequent skirmish for resources. If you didn’t know, Vibrio cholerae, the type of bacteria used in this experiment, have poisonous, harpoon-like parts to kill competitors, like other bacteria. The poison used to kill is known as Type VI secretion, and it’s common in the bacterial world. Cholera harpoon all bacteria they touch – even bacteria that are the same strain. However, Vibrio cholerae that have immunity to the poison aren’t affected by each other’s barbs. As such, the colonies of cholera with immunity to the Type VI secretion end up killing other bacteria, including non-immune strains of cholera, but do not harm themselves.


As the publication explains, the researchers borrowed some equations from physics to predict how a bacterial battle between one cholera strain with immunity to the poison and one without immunity would play out. The results found that the physics equations forecasted accurately the timing of an important part of the battle, known as phase separation, which is when the different strains of bacteria separate from each other, like oil and water. You can imagine the implications of such a discovery when you think of how effective a military force would be if it could mathematically predict how a human conflict would unfold. This concept is no less powerful when applied to the targeting of harmful bacteria in the human gut. Such therapies are admittedly nowhere near existence at this point, however as the history of antibiotics has shown, understanding and harnessing the biological processes of bacteria can change the course of humankind. So, physics, today the life sciences salute you. Oh, and you too, Georgie Tech researchers!