The Science

Farm antibiotics and human resistance

The contribution of farm antibiotic use to human resistance is widely recognised, including by the 2016 O’Neill AMR report, the World Health Organisation and the European Food Safety Authority.

The routine overuse of antibiotics in farm animals creates perfect conditions for the emergence of resistant bacteria, killing off susceptible bacteria while allowing stronger resistant bacteria to survive.

These bacteria can then spread to people: through handling meat, through direct contact with animals, or through the environment. Sometimes, resistant bacteria that have come from animals can ‘colonise’ a human, but not cause an infection until years later.

This presents a big risk to human health, as many of the antibiotics used in farming belong to the same class as those used to treat serious human infections.

What we know

  • For some human infections such as Campylobacter or Salmonella, farm antibiotics use is the main cause of resistance in human infections
  • Farm antibiotic use is has significantly contributed to the rise of a new and almost untreatable type of E.coli, which is causing large numbers of deaths in the UK and elsewhere
  • The high use of certain antibiotics in farming has caused the emergence of a new strain of MRSA in animals, which is spreading rapidly and transferring to humans
  • Humans are increasingly becoming resistant to the ‘critically important’ antibiotics. This is driven in part by inappropriate use of antibiotics in veterinary medicine

In late 2015, resistance to the ‘last-resort’ antibiotic colistin was discovered in people and pigs in China, strongly linked to the overuse of colistin in farm animals.

Colistin resistant bacteria was then rapidly discovered in a number of countries worldwide. In December 2015, the Alliance to Save our Antibiotics revealed the presence of the colistin-resistant gene in the UK. This development represents the breach of our last defence against infection, and serves as a frightening indication of what is to come.

We are approaching a post-antibiotic age, where standard medical treatments will fail, and simple procedures and operations could once again kill.

Read our reports