Antibiotic-resistant superbugs threaten to plunge the world back to the "dark ages" of medicine, according to David Cameron, who pledged that the UK will lead a global effort to develop new drugs. The prime minister went on to call for a coordinated global response to the emergence of untreatable bacteria, which he decribed as one of the biggest health threats facing the world today.

"This is not some distant threat, but something happening right now," Cameron told the Times. "If we fail to act, we are looking at an almost unthinkable scenario where antibiotics no longer work and we are cast back into the dark ages of medicine, where treatable infections and injuries will kill once again. That simply cannot be allowed to happen and I want to see a stronger, more coherent global response."

The prime minister is to announce an independent review led by Jim O'Neill, the former chief economist at Goldman Sachs, to identify why new drugs have failed to emerge on the international market. The review is expected to focus on the development and regulatory environment around antibiotics.

Cameron, who said earlier this month that immediate action is needed to accelerate the development of drugs for dementia and oversaw a push during the UK's G8 presidency last year to set a global ambition of finding a cure by 2025, is said to have raised the issue of antibiotic-resistant superbugs during last year's G7 summit.

He went on: "When we've had these problems in the past, whether it is how we tackle HIV and Aids, how it is possible to lead the world and get rid of diseases like polio, Britain has taken a lead and I think it is right we take a lead again."

Scientists estimate that there are 5,000 deaths a year in the UK due to strains of bacteria that have evolved resistance to antibiotics. There have been warnings that the continuing rise in resistance could have wider repercussions in the future. Surgery, and treatment for diseases such as leukaemia, would be hard to carry out if there were no means to kill off random infections in patients.

The pharmaceutical industry has produced three generations of antibiotics in the past 60 years. The first included natural penicillins. However, this group fell by the wayside as bacteria evolved enzymes that broke the drugs apart. The second were synthetic penicillins, modified in the lab to resist the bugs' enzymes. Bugs gained resistance to these too. The third generation, carbapenems, have been further modified. In 2003, the first microbes arrived in Britain that are immune to even these.