Polymyxins – a group of drugs classed as critical to human medicine – were until now the only group of antibiotics that worked when all others had failed.
But experts have identified the first germs to become resistant to the drugs. They warned of the inevitable spread of uncontrollable superbugs that attack the blood and lungs.
The discovery was made by Chinese doctors working with UK experts from Bristol and Cardiff universities.
Writing in the medical journal Lancet Infectious Diseases, they said they had found a gene which enables infectious bacteria such as E.coli to become untreatable. The alarming findings show that the mobile gene can easily be transferred to other types of bacteria.
Bugs such as Klebsiella, which causes pneumonia and blood infections, could become resistant to treatment as a result, the team found.
A major problem is that polymyxins are widely used in farming. If bugs in animals become resistant to the drugs, they could be transferred to humans who eat the meat.
Professor Nigel Brown, president of the Microbiology Society, said: ‘Another line of defence against infection is in danger of being breached.’
Chief Medical Officer Dame Sally Davies fears patients will soon die from cuts and routine operations as a result.