Antibiotics are natural compounds produced by certain bacteria and fungi. We use them to target parts of bacterial cells that aren’t found in human cells. Over the years, we have harnessed their power as drugs, to fight bacterial infections, but till date, antibiotics don’t work against viruses like colds and flu.

Different kinds of antibiotics work in different ways. Many target the bacterium’s cell wall, a tough outer coating that gives the bacteria strength and support. Without a cell walls, the bacteria burst open and die. Other antibiotics don’t kill the bacterial directly, but stop them from reproducing, which slows down their growth.

But there’s a problem. Some bacteria are becoming resistant to antibiotics, meaning our drugs are no longer effective against them.

This is very bad news. A world without antibiotics would be like going back to the dark ages. Simple operations or mild infections could kill. A big part of the problem is caused by the overuse of antibiotics. Antibiotics don’t last forever, and bacteria do eventually develop resistance to our drugs.

But by overusing antibiotics and overexposing bacteria to them, we’ve greatly accelerated this process. For example, over time, bacteria can evolve ways to pump antibiotics out of a cell, like bailing water from a sinking ship, or they can produce chemicals that target and neutralize antibiotic molecules.

To make things worse, bacteria can also transfer genes for resistance between each other, and even to other species. This means that once resistance develops, it can spread very quickly. If you are infected by resistant bacteria, the only option is to give you different antibiotics in the hope that they will treat the infection.

But some bacteria like MRSA are known as superbugs, because they’re resistant to multiple types of antibiotics. These bacteria are particularly dangerous because they are so difficult to treat, if they can be treated at all.

But there are things we can do to slow down the emergence of resistance. We shouldn’t demand antibiotics from doctors for viral infections like flu, because that won’t work. We should only prescribe antibiotics when necessary.

Sometimes it can be better to let the body fight off an infection on its own, and if you are prescribed antibiotics, you should finish the dosage even if start feeling better. This is to make sure the treatment kills all the bacteria and doesn’t leave any behind that could turn resistant.