What if all our antibiotics stopped working?
Bacteria are waging war on our drugs, and defeat is not an option
Until the 1940s, one in 20 children died before their first birthday. Tuberculosis and pneumonia had no cure, and a simple cut could turn a limb gangrenous, resulting in amputation. Antibiotics stop bacteria dividing, slow their growth or burst them open, helping our immune cells to clear infections. They eliminate deadly diseases, allow us to open the body up for surgery and protect cancer patients from infection. They make it possible to farm animals and fish on an industrial scale, and their presence in cleaning products stops the spread of disease. But bacteria are fighting back. In 2016, 700,000 people died as a result of antibiotic-resistant infections, and by 2050, 10 million lives a year could be at risk. Like us, every individual bacterium is slightly different, so when a colony of bacteria encounter antibiotics Darwin’s survival of the fittest kicks in. Some individuals do better than others, living longer and passing on their genes. This makes the next generation a little bit better at resisting the effects of drugs. That next generation also accumulates random mutations, making them each a bit different from one another again. Some get even better at resisting antibiotics and the cycle repeats. These small improvements start to add up, and eventually, we end up with bacteria that we just can’t kill.
We are in an arms race with these microscopic organisms. They are evolving molecules that ignore antibiotics, inactivate them, or even pump them out of their cells. What’s more, thanks to a quirk of bacterial biology, once one species has developed a way to resist a drug, it can donate its genetic code to another species, passing the resistance on. If our drugs stop working, treatable infections could once again become deadly, the risk of infection after surgery could rise, and industrial farming could become impossible. It’s a race against time to find new ways to fend them off, a race that we can ill afford to lose.
The rise of resistance
A mixed army
Each bacterium in a colony is slightly different – some are naturally a little harder to kill than others.
The strong remain
Antibiotics kill or inactivate the weakest bacteria first, thereby leaving the stronger bacteria behind.
Share to survive
The offspring of the surviving bacteria inherit the genes that make them harder to kill.
Bacteria can share genes, allowing them to pass antibiotic resistance to other species.
This article was originally published in How It Works issue 119, written by Laura Mears
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