All plant and animal species are subject to their sometimes-deadly attention. Not all bacteria are harmful to humans however. The human body has evolved its own defensive strategy to fight serious bacterial infection - for most of the time our immune system is brilliant at coping with these microbes. Sometimes however, our immune system is overwhelmed in a ferocious bacterial attack. At these times, modern medicine turns to antibiotics - naturally occurring chemical compounds that kill bacteria.
Most people think of antibiotics as powerful drugs that quickly wipe out nuisance infections.
Increasingly however, resistant strains of deadly bacteria are emerging that are challenging our ability to kill them and so threaten virtually all modern surgical techniques. Bacteria have fought back and again look set to out-manoeuvre our attempts at control. The AS Guru TV Question - top tips on how to structure your answer For more about antibiotics on AS Guru TV, click where you see a text link under the TV icon on the right. Then note down the TV timecode to find the exact spot in the programme.