Most antibiotics are natural products of bacteria and other microorganisms from the environment. They are part of a silent chemical warfare among microorganisms in soils, rivers and seas right now. The fact that they are natural products that have been around for millions of years means that even as we discover new antibiotics, there are probably already microorganisms that are resistant to them.
One of the most effective ways that scientists combat antibiotic resistance is by making semi-synthetic antibiotics. They change the structure of the antibiotic molecules so that they still kill the bacteria and the resistance that the bacteria have against them doesn’t work – at least for a while.
