Scientists from Harvard Medical School (HMS) and Technion-Israel Institute of Technology recently conducted an experiment to show how bacteria can become resistant to increasingly higher doses of antibiotics and survive in them. 

In a time-lapse video published by HMS, one can see the movement of bacteria and how they adapt to the increasingly higher concentration of drugs on a 2-by-4 foot petri dish over the course of 11 days. 

Bacteria, which are sensitive to antibiotics, eventually mutate and develop resistance to it over a short period of time. 

How the experiment was done

An HMS report on the experiment described the procedure as such:

"To do so, the team constructed a 2-by-4-foot petri dish and filled it with 14 liters of agar, a seaweed-derived jellylike substance commonly used in labs to nourish organisms as they grow."

"To observe how the bacterium Escherichia coli adapts to increasingly higher doses of antibiotics, researchers divided the dish into sections and saturated them with various doses of medication. The outermost rims of the dish were free of any drug.  The next section contained a small amount of antibiotic—just above the minimum needed to kill the bacteria—and each subsequent section represented a 10-fold increase in dose, with the center of the dish containing 1,000 times as much antibiotic as the area with the lowest dose.

Michael Baym, research fellow in systems biology at HMS, said “We know quite a bit about the internal defense mechanisms bacteria use to evade antibiotics but we don’t really know much about their physical movements across space as they adapt to survive in different environments.” 

The researchers however said that this experiment does not perfectly mirror how bacteria moves and adapts in the real world.  

"The researchers caution that their giant petri dish is not intended to perfectly mirror how bacteria adapt and thrive in the real world and in hospital settings, but it does mimic more closely the real-world environments bacteria encounter than traditional lab cultures," the HMS report adds. 

Interestingly, the researchers, who wanted to teach students evolution through a visually captivating way, adapted the idea for the experiment from Hollywood.

To know more about the experiment, read Bugs on Screen.

Watch the video here: