Bacteria resistant to antibiotics have spread to every part of the world and might lead to a future where minor infections could kill, says a new report.
The World Health Organisation (WHO) described antibiotic resistance as a "major threat" to public health and warned that "the implications will be devastating".
"The world is headed for a post-antibiotic era, in which common infections and minor injuries which have been treatable for decades can once again kill," said Keiji Fukuda, the WHO’s assistant director-general for health security.
The WHO said it found very high rates of drug-resistant E. coli bacteria, with treatment for the bug useless in more than half of patients in some countries.
The report also found worrying rates of resistance in other bacteria, including common causes of pneumonia and gonorrhoea.
At least 10 countries - including Britain - now report having patients with gonorrhoea that is totally untreatable.
Drug resistance is driven by the misuse and overuse of antibiotics, which encourages bacteria to develop new ways of overcoming them.
The WHO said people should only use antibiotics when prescribed by a doctor, that they should complete the full prescription and never share antibiotics with others or use leftover prescriptions.