Antibiotics have long been considered the 'silver bullet' against infection. Now, medical experts are concerned superbugs could render antibiotics useless, taking medicine back 70 years. The widespread use of the drugs means that resistant strains of bacteria are evolving in rich and poor countries alike. Without new antibiotics, even the simplest surgeries could become perilous. Discussions of what should be done were at the top of the agenda at a European conference on infectious diseases in Berlin.