There have always been bacteria resistant to antibiotics! however the over use and non correct use of antibiotics has caused many more bacteria to be resistant. but how does this work? Well have you ever heard what doesn't kill you makes you stronger? As the diagram illustrates when we kill bacteria that are susceptible to antibiotics it only leaves resistant ones behind. These bacteria then multiply and pass on there genetic information which allows them to be resistant to other bacteria. The selective pressure from the antibiotics have created populations of super bugs which cannot be killed. How do you stop the spread of super bugs? Well its actually really simple don't over use antibiotics! and when you actually have to take antibiotics take all of them! If you don't finish off your prescription you may not kill all the bacteria. This means you've only left the strongest bacteria which will then multiple and pass on their DNA!