The World Health Organisation (WHO) is calling for more urgent action to deal with drug-resistant infections after a bacteria which resists almost all antibiotics was discovered.

WHO issued a stark warning that the world is on the brink of a post-antibiotic era when many common infections will no longer have a cure.

And there may be a new culprit in the crisis, after a gene which makes bugs resistant to drugs was discovered in the drinking water of one of the world's biggest cities, New Delhi.

It is a losing battle given top priority by WHO director-general Dr Margaret Chan.

She is using her World Health Day address to warn that bugs are overcoming drugs at a much faster rate than new drug development.

"The world is on the brink of losing these miracle cures," she said.

"The emergence and spread of drug-resistant pathogens has accelerated."

WHO says at least 440,000 new cases of multi-drug-resistant tuberculosis were detected last year.

The malaria parasite is acquiring resistance and resistance is also emerging to the antiretroviral medicines used to treat people with HIV.

Dr Chan says the implications are clear: the world is heading towards a post-antibiotic era where common infections will once again kill unabated.

For many years so-called superbugs have been largely confined to hospitals, but now they are becoming harder to contain.

'Major concern'

The Lancet Infectious Diseases journal reports that the people of New Delhi are continually being exposed to NDM-1-positive bacteria through the city's drinking water.

The gene NDM-1 has spread to germs that cause cholera and dysentery and it makes bacteria resistant to almost all antibiotics.

Dr Hatch Stokes, immediate past president of the Australian Society of Microbiology, says it is "a major concern".

"Antibiotic resistance as you say is a big problem in the clinical environment, but I think there's been evidence accumulating over several years now that antibiotic-resistant genes are starting to make their way into the general environment as well," he said.

"And certainly the findings that this particular resistance gene NDM-1 is broadly disseminated in a water supply is a great concern."

Dr Stokes has called the gene, discovered in India in 2008,"particularly nasty".

"It confers resistance to the very important family of drugs referred to as penicillins," he said.

"In the case of NDM-1 it confers resistance to virtually all of them - this family of drugs.

"So when it gets into a hospital such infections can be very difficult to treat and the fact that people are carrying it in the general environment means that it's likely to spread throughout the globe very quickly."

Australia not immune

Dr Stokes says it is a development which will eventually lead to more untreatable infections in Australia.

"I think that's inevitable. Certainly it's spread to Europe and other parts of the world very quickly," he said.

"So it is rapidly emerging as a global problem and I think it's inevitable that we're going to have the same problem here in Australia.

"It's a very big problem, as I said, because the penicillins have been used for many years to treat multi-drug-resistant infections.

"And really the presence of this particular gene virtually eliminates the efficacy of almost all penicillin."

While delivering her World Health Day message, Dr Chan urged each country to do more to combat drug resistance.

"In a time of multiple calamities in the world we cannot allow the loss of essential medicines, essential cures for many millions of people to become the next global crisis," she said.

Federal vice-president of the Australian Medical Association Steve Hambleton says it is a warning Australia should heed.

"We do need to monitor these things," he said.

"Every state's got public health units and their work has got to be coordinated so that these sort of things can be monitored and actually plans put in place to stop them spreading."

WHO says each country needs to strengthen surveillance of drug resistance and implement a national plan to combat it.