Warnings about the approaching post-antibiotics apocalypse have been sounding for years. There are now strains of deadly bacteria that are resistant to all antibiotics. This means that doctors are faced with patients who have completely untreatable infections. Hundreds of thousands of people worldwide are dying due to antibiotic resistance - and this number is set to rise rapidly. If we carry on like this, scientists predict we will return to a pre-antibiotic era, where organ transplants, chemotherapy and C-sections are impossible. We have come a long way since 1928, when the famous chance discovery of penicillin led to a golden age in which antibiotics were seen as wonder drugs, heralding in an age of huge medical advances and increased human life spans. But by the 1990s we were running out of new antibiotics and infections were again a killer. How did this happen? Our expert witnesses are medic and historian, Dr Eric Sidebottom, Dr Scott Podolsky of Harvard Medical School, journalist Maryn McKenna and infectious disease specialist Brad Spellberg. (Photo: A depiction EHEC bacteria. Credit: HZI/Getty Images)