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Watch E.coli Evolve Before Your Eyes

This is how antibiotic resistance happens

smithsonian.com

It's well known that bacteria can evolve to be more resistant to antibiotics. But how quickly does it morph? More quickly than you might think. As Margaret Rhodes reports for WIRED, it takes no time at all for E. coli gut bacterium to become more resistant to antibiotics—and scientists captured it all on camera.

The video you see above is a strain of E. coli filmed over the course of 11 days. Think of it as an illustration of evolution in action—bacteria was placed on a huge petri dish, given doses of trimethoprim, an antibiotic, and left to morph. The experiment is described in a new paper in the journal Science, and it illustrates just how terrified we should probably be of antibiotic resistance.

As Rhodes reports, it also demonstrates the power of really huge petri dishes. The film was made on a so-called MEGA-plate (short for Microbial Evolution and Growth Arena plate), a petri dish on steroids that was inspired by an ad for the movie Contagion. Since the plate dish is so big—two feet by four feet—it’s the ideal place to observe evolution in action.

As Susan Scutti writes for CNN, scientists chose E.coli for the demonstration because it can swim, unlike many other microscopic organisms. The bacteria was placed on the plate and fed increasing doses of trimethoprim, which is used to treat some types of pneumonia and urinary tract infections. The outer area of the plate was kept antibiotic-free, but inside the plate the dosage was increased 1,000 times over.

What happened was all captured on camera. “Multiple coexisting lineages diversified both phenotypically and genotypically,” write the paper’s authors. This means that the strains of E. coli that survived the antibiotic morphed, evolved and went on to colonize the entire area treated with the same dose of antibiotic. With each generation, the bacteria became increasingly drug resistant.

The visualization isn’t just a cool science experiment—it’s a chilling reminder that antibiotic use can breed savvier, more resistant bugs. Antibiotic resistance, which could soon diminish the ability to treat long-managed diseases like gonorrhea, can make conditions that once were under control dangerous again as bacteria get smarter and stronger. It’s such a pressing issue internationally that the UN is holding a summit on the topic this month. Perhaps armed with visualizations like the one above, it will be easier for scientists and policymakers to garner support and curb antibiotic use before it's too late.

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