Bacteria that resist the most common antibiotic of last resort - colistin - have been discovered in the UK.Officials say the threat to human health is low, but is under ongoing review.

Scientists warned the world was on the cusp of a post-antibiotic era when such resistance was discovered in China last month.

Now checks have discovered the same resistance on three farms and in samples of human infections.When all other antibiotics fail then doctors turn to colistin - that’s why it is so important.

Doctors in the UK thought they had three years before colistin-resistance would spread from China to the UK.But Public Health England and the Animal and Plant Health Agency began testing for it.

Public Health England has gone through the 24,000 bacterial samples it keeps on record from cases between 2012 and 2015.

Colistin-resistance was discovered in fifteen of them, including samples of Salmonella and E. Coli.

The Animal and Plant Health Agency has discovered colistin-resistant bacteria on three pig farms.