Colistin use in animal feed increasing antibiotic resistance in humans

A new study has found that although use of the antibiotic colistin has been banned in farming by many high-income nations, including China and the European Union, it is still being exported to low and middle-income countries, such as Pakistan, Nigeria and Bangladesh.

Lack of regulations & trade on national levels

International research led by scientists at the University of Oxford and the University of Agriculture, Faisalabad, Pakistan, found that despite agreements on limiting the use of antibiotics in farming, the lack of regulation at trade and national levels, has meant the drug is being used extensively in countries where other treatment alternatives are either expensive or inaccessible. The study also identified a range of colistin products manufactured to be used in paediatrics and marketed as “Antibiotic – Anti diarrhoeal.”

The use of human antibiotics in animal feeds is one of the largest drivers on antibiotic resistance globally.

Colistin-resistant E.coli

Researchers have identified a growing prevalence of colistin-resistant E.coli isolated from the environment and food animals in Pakistan, in 7% of samples compared to a global average of 4.7%. The resistance was also observed in human isolates.

For ban to be successful – alternations are needed

Professor Timothy Walsh, research director at the Ineos Oxford Institute for Antimicrobial Research and co-author of the study, said:

“The use of human antibiotics in animal feeds is one of the largest drivers on antibiotic resistance globally. While many high-income countries have reduced their use of antibiotics in farming, paradoxically, they are still exporting drugs like colistin to low-income and middle-income countries.

“We need to stop using human antibiotics for animal feeds. However, such a ban without alternative solutions will lead to a decrease in meat production, increase in prices and loss of income for farmers.

“One of our key areas of focus at the Ineos Oxford Institute is to develop new drugs that can be used exclusively in animal feed. In the meantime, we need to support farmers to improve farm hygiene and protect animal welfare with the aim of decreasing reliance on human antibiotics.”

Limited understanding of the consequences of colistin usage

The study, published in the Lancet Microbe, found that farmers using the drugs had limited understanding of the consequences of colistin usage and highlights the importance of supporting farmers to make sustainable improvements of their farming practices.

Dr Mashkoor Mohsin, fellow co-author from the University of Agriculture, Faisalabad, Pakistan, said there needed to be a change in the way antibiotics were manufactured, traded, licensed, and used for veterinary purposes. At the same time, animal and farmer welfare could not be ignored.

“Such a global shift will require considerable commitment from national governments, financial institutions, pharmaceutical companies and international trade regulators,” added Mohsin.

The report can be found here