Study: 'Invincible' bacteria threatens global epidemic

Medicine's final line of defense against deadly disease has been breached, raising the specter of a global epidemic, scientists say, after finding bacteria resistant to last-resort antibiotics.

The discovery could herald a return to the Dark Ages, with doctors unable to control common germs like E. coli, rolling back centuries of medical progress.

"These are extremely worryingly results," said Liu Jianhua, a professor at China's Southern Agricultural University and co-author of a new study.