Bacteria like E.coli have mutated to be resistant to our last-line antibiotics and untreateable bugs may already be circulating, scientists have warned. Health experts have warned for years that antibiotic resistance could send medicine back to the dark ages, with even the smallest infections proving lethal.Currently, when all other drugs fail, doctors use polymyxins - such as colistin - as a last resort to treat bacterial infections like E.coli and those which cause pneumonia.But British scientists have discovered that meat from pigs slaughtered in China is infected with bacteria carrying a new gene that makes them resistant to these rearguard antibiotics.The MCR-1 gene is in a part of the DNA which can be easily copied and transferred between bacteria, leading experts to conclude that "pandemic resistance is inevitable".The mutated forms were also found in 1322 hospitalised patients in China and are thought to have already spread to Laos and Malaysia. ..