Bacteria are everywhere on the planet: on and in other living beings, but also in the air, the water and the soil. They are not all relevant for humans and animals – but without bacteria there would be no life on earth. Antibiotic-resistant bacteria (both those that cause disease and those that don’t) can be found in the most remote corners of the planet, because microbes and fungi have been producing antibiotics themselves for billions of years to protect themselves. However, various forms of bacterial resistance have also evolved since humans started to use antibiotics in order to treat themselves and their pets or farm animals.