In this video, you can literally see evolution happening over the course of just days.
Researchers at Harvard and the Technion–Israel Institute of Technology have set up what’s essentially a giant rectangular petri dish, called the "microbial evolution growth arena plate" (MEGA plate for short).
Bacteria are then introduced at each end of the table and do what they do best: spread and multiply.
At each end of the MEGA plate, there are no antibiotics. But every several centimeters in toward the center, the scientists paint bands of antibiotics of increasing potency. Each increase of antibiotic concentration is a stressor that the bacteria (they’re just regular E. coli) have to cope with. That is, the bands of increasingly powerful antibiotics (either trimethoprim or ciprofloxacin) are provoking the bacteria to evolve, outsmarting the medicines that are designed to kill them.
It’s both beautiful and terrifying to see antibiotics be powerless against almighty evolution. You can see the bacteria (shown in milky white) all stopped at the first band of antibiotic.
But then a small group of bacteria, containing a mutation that allows them to survive the chemical assault, break through. Those mutant bacteria become the dominant type in the population. This process repeats for each more powerful band of antibiotics, until the bacteria achieve total resistance at the center.
(The video is a time lapse of the bacteria’s progress over 12 days.)
The researchers — who published this visualization method in the journal Science in September — hope this technique will help them better understand the complicated patterns underlying antimicrobial resistance, which is a growing concern in hospitals around the world.
The MEGA plate also provides us non-scientists a great way to visually understand how antibiotic resistance occurs.
Thirty percent of all antibiotic prescriptions are unnecessary, a recent report in JAMA concluded. When doctors prescribe antibiotics needlessly for things like colds, they increase the opportunities for bacteria become resistant to them. The Centers for Disease Control and Prevention estimates that 23,000 people died from resistant infections in 2013. It's been estimated that by 2050, antimicrobial-resistant diseases will kill more people than cancer.
We need to think of better solutions to this overuse of antibiotics. As the video above clearly shows, the answer isn’t using more of them.
Further reading:
- Check out Julia Belluz’s explainer on how the problem of antibiotic resistance got so bad and what can be done to stop it.
