Bacteria Killing Their Competitors by Following ‘Divide and Conquer’

In a new study led by the research group from Imperial College London, researchers have experimented to see the result of bacteria provoking their competitors.

Some bacterial strain releases a toxin agent which evoke other bacteria in their surroundings to attack. Scientist hopes that this tactic can be used against the infectious disease.

The conflict for the food resources between the natural gut flora or the infection causing bacteria to lead to ‘warfare’ in which the bacteria release toxin to kill or harm the other bacterial communities.

Moreover, to kill the competitors they also release provoking toxins which increase the aggression of opposite community by enhancing their toxin response.

During their research, scientist found that when bacteria were provoked against single competitors, provoked strains respond by producing an even stronger toxin which in turn harms the provoking strains.

But when they experimented with 3 or more bacterial strains they found that provocation causes the other competing strains to increase their violent behavior and attack more on each other. This can lead to the competitors wiping each other out, especially when the provoking strain is shielded from, or resistant to, their toxins.

Senior author Dr. Despoina Mavridou, from the Department of Life Sciences at Imperial, said: “This behavior is strongly reminiscent of the human ‘divide and conquer’ strategy, famously delineated by Niccolò Machiavelli in his book The Art of War and shows that bacteria are capable of very elaborate warfare tactics.”

The researchers suggest that the strategy could be exploited to manipulate microbial communities. Lead author Dr. Diego Gonzalez, from the University of Lausanne, said: “We could envisage exploiting provocation in alternative antimicrobial approaches. For example, exposing established bacterial communities to low levels of known antimicrobials could promote warfare and cross-elimination of different strains.”

This approach could be particularly useful to help eradicate resistant biofilms – layers of bacteria that form for example in industrial water pipes and are hard to remove. It could also be used to treat some bacterial infections if the composition of the bacterial community responsible for the infection is well known.

Dr. Mavridou added: “By provoking other strains to attack each other, the toxin of the provoker is more effective than what would be expected based on its real toxicity. Using toxin-mimicking chemicals, we could potentially manipulate microbial aggression to our own benefit.”