But with increasing numbers of people embarking on so-called  'health tourism' trips to India and Pakistan for cheaper treatment the superbug could quickly spread, the scientists warned.

"At a global level, this is a real concern," Timothy Walsh, who led the study, said.

"Because of medical tourism and international travel in general, resistance to these types of bacteria has the potential to spread around the world very, very quickly. And there is nothing in the [drug development] pipeline to tackle it."

Positive samples

Multi drug-resistant bacteria are already a growing problem in hospitals across the world, marked by the rise of superbug infections like methicillin-resistant Staphyloccus aureus [MRSA].
   
Walsh and his international team collected bacteria samples from hospital patients in two places in India - Chennai and Haryana - and from patients referred to Britain's national reference laboratory between 2007 and 2009.

They found 44 NDM-1-positive bacteria in Chennai, 26 in Haryana, 37 in Britain, and 73 in other sites in Bangladesh, India, and Pakistan.
   
Several of the British NDM-1 positive patients had recently travelled to India or Pakistan for hospital treatment, including cosmetic surgery, they said.

Experts commenting on Walsh's findings said it was important to be alert to the new bug and start screening for it early.

"We are potentially at the beginning of another wave of antibiotic resistance, though we still have the power to stop it," Christopher Thomas, a professor of molecular genetics at the University of Birmingham who was not linked to the study, said.

Thomas said better surveillance and infection control procedures might halt the gene's spread.

He said while people checking into British hospitals were unlikely to encounter the superbug gene, they should remain vigilant about standard hygiene measures like properly washing their hands.