Antibiotics are now failing to work in a fifth of patients who suffer an infection after hospital surgery, according to the first major study investigating the crisis.

The global research, published by the Lancet, found that one in eight patients undergoing common procedures such as appendix removal developed an infection while recovering. And 22 per cent of cases were found to be resistant to the antibiotics which should have protected them.

The study, led by the University of Edinburgh, tracked more than 13,000 patients in 66 countries, including those in the UK, who were undergoing gastrointestinal surgery.

Researchers said the findings were “extremely worrying,” with potentially “catastrophic” consequences.

Prof Dame Sally Davies, the chief medical officer for England, has warned that antibiotic resistance proves as great a threat to the nation as terrorism.

The new research - the first such detailed study to track the subject on such a scale - found levels of antibiotic resistance were highest in the poorest countries, where they were most frequently doled out.