Health experts from around the world yesterday tested how they would cope if there was a global pandemic of an antibiotic-resistant superbug.
Leaders from the G20 countries gathered in Argentina for a simulation which checked their ability to deal with a crisis caused by a fast-spreading infection.
A fictional outbreak of E. coli, a nasty bug that often causes diarrhoea, challenged the governments.
The exercise was run following warnings earlier in the year that countries around the world aren't prepared for an global pandemic.
The UK and Argentinian governments ran the experiment, which involved members of the all G20 countries.
The other G20 members are Australia, Brazil, Canada, China, France, Germany, India, Indonesia, Italy, Japan, Mexico, Russia, Saudi Arabia, South Africa, South Korea, Turkey, the US and the EU.
During the simulation, countries were tested on their ability to act quickly to contain an infection which couldn't be treated with normal medications.Health systems would be put under pressure, the infection would spread across borders, and members of the public and livestock's lives would be put at risk.
Government experts decided how their fictional countries would act to contain the infection in an exercise meant to train them in the global fight against drug-resistant bugs.
Dame Sally Davies, chief medical officer for England, ran the exercise and said: 'Antimicrobial resistance is an escalating global threat that demands action from all countries.
It was hoped the day would help countries understand how they can fight back against the threat of antibiotic resistance, also known as antimicrobial resistance (AMR).
Public health minister Steve Brine added: 'The UK is at the forefront of global action on AMR and while some progress has been made both at home and internationally, we cannot afford to lose ground.
'Superbugs do not recognise borders and our response must not be constrained by them either.'
Experts have warned more than once this year about the looming threat of the spread of an infection which will be resistant to common medicine.
We would be 'powerless' to stop a killer flu virus and a global pandemic could end up killing 900 million people if it started to spread tomorrow, it is claimed.
A similar event held in the US in May found it would take decades for scientists to produce a new vaccine if a previously-unknown virus were to break out.
Dr Eric Toner from Johns Hopkins University in Baltimore said at the time: 'We don’t have the ability to produce vaccines to a novel pathogen within months rather than decades.
'And we don’t have the global public health capabilities that would allow us to rapidly identify and control an outbreak before it becomes a pandemic.
'It will happen, but I don’t know when.'