We've over-used antibiotics for a long time, and this has encouraged bacteria to evolve. Some have become 'resistant' - antibiotics don't have an effect on them any more. Today's easily treated infections could be fatal in the future if we don't come up with new medicines.
To help focus global efforts against antibiotic resistance, the World Health Organization has published a list of 12 bacteria we urgently need new drugs for. It includes the 'hospital bug' MRSA and food poisoning bacteria such as E. coli.
A future where common infections become untreatable worries me - we need to do everything we can to avert it.