Bacteria that are resistant to the last line of antibiotics have been detected in the U.K., the BBC reported. "Our assessment is that the public health risk posed by this gene is currently considered very low," Alan Johnson, head of the Department of Healthcare Associated Infection and Antibiotic Resistance at Public Health England, told the Daily Mail. He added that the situation is being reviewed.

However, other experts disagree. Dr. David Brown, director of Antibiotic Research U.K., believes it is "almost too late" to avoid a global crisis involving antibiotic-resistant bacteria. He blamed the problem on antibiotic misuse in agriculture.

"We needed to start research 10 years ago and we still have no global monitoring system in place," Brown told The Guardian. "The issue is people have tried to find new antibiotics but it is totally failing -- there has been no new chemical class of drug to treat gram-negative infections for more than 40 years."

When Chinese researchers announced last month that they detected a gene that makes bacteria resistant to colistin -- the antibiotic drug that is used when all other antibiotics fail -- researchers estimated that it would take at least three years for the superbugs to spread to U.K.

However, testing for colistin-resistant bacteria conducted by Public Health England and the Animal and Plant Health Agency revealed that 15 out of 24,000 bacterial samples had the mcr-1 gene. The samples were collected from 2012 to 2015 in the U.K.

The gene was detected in Salmonella that infected 10 people and in E. coli that infected two people. It was also present in bacterial samples collected from three pig farms and imported chicken meat.

The mcr-1 gene makes bacteria resistant to colistin, the antibiotic treatment that is normally used when all other antibiotics fail. It can be passed easily from one species of bacteria to another.

Dame Sally Davies, chief medical officer in Britain, called for the reduction of antibiotic use in agriculture.

'If we don't act now, any one of us could go into hospital in 20 years for minor surgery and die because of an ordinary infection that can't be treated by antibiotics," Davies said. "And routine operations like hip replacements or organ transplants could be deadly because of the risk of infection."

The mcr-1 gene has also been found in Denmark, the Netherlands, France, Malaysia and other Asian countries.