Bacteria rampage

Ever read about the Brazilian model who died from bacteria infection? It would be very rare, at least for an adult to die from it. So what actually happened? The doctors were fighting against drug resistance bacteria. If that is the case, how did the bacteria become so strong. It all boils down to misues of drugs. People everywhere are using drugs on everything minor. Or when doctor gives the drug to a patient, the patient did not finish the drug, which would in turn give the bacteria a chance to mutate against the drugs. So this could be man's undoing if such a day where bugs started to infect people and drugs are useless. The science seems to be slower in developing than the mutating of bacteria.