Global action on antimicrobial resistance
Last year a UK-China research collaboration took an unexpected turn following the discovery of resistance to the ‘last resort’ antibiotic: colistin. Here Professor Timothy Walsh, Professor of Medical Microbiology at Cardiff University, describes how the global community can learn from the positive steps taken by the Chinese Government.
Antibiotic resistance is really all about people and society. We often blame antimicrobial resistance on the bug and how resistance can travel from one bug to another. But different sectors, for example farming, hospitals and communities, are all critically linked.
Stopping the spread
This month the Chinese Government took a hugely positive step towards tackling the spread of antibiotic resistance. As of 1 November, the Chinese Ministry of Agriculture banned the use of the antibiotic colistin as a feed additive for animals. The results of our UK-China research collaboration were critical to informing this decision.
We discovered a gene called MCR-1 that confers resistance to colistin. MCR-1 is what we call a ‘mobile gene’ meaning it can be easily transferred to other bacteria, making them resistant too. Last year we found this gene in animals and humans in China.
Colistin is an important ‘last resort’ antibiotic, used to treat serious bacterial infections in humans resistant to other antibiotics. It is also used in animal feeds to help rear healthy animals.
But widespread use of the antibiotic means large-scale exposure to the surrounding environment, including humans and bacteria. The knock-on effect is the development, and spread, of resistance genes. These genes render bugs resistant to potentially life-saving drugs.
An unexpected discovery
I started working on an antimicrobial surveillance project of farm animals in China, thanks to an exceptional young scientist from Beijing called Yang Wang. He encouraged me to work with Professor Jianzhong Shen’s group at the China Agricultural University. My research focuses on the impact of antimicrobial resistance in clinical infections in humans. But when Yang told me about the problem of colisitin-resistance in China at a conference two years ago we decided to collaborate.
It was through this project that we made our unexpected discovery of the colistin-resistance gene, MCR-1*. It came from a strain of bacteria called Escherichia coli that was found in pigs.
Our discovery had international significance as the first example of a mobile colistin-resistance gene. The colistin resistance could be transferred between bacteria via a plasmid – a small, circular, DNA molecule that can replicate independently. Since then, the MCR-1 resistance gene has spread to more than 30 countries or regions, spanning four continents.
Our findings emphasised an urgent need for action in the fight against this type of resistance. So as soon as we knew our data we consulted with Chinese Government officials.
We met with ministers from the Ministry of Agriculture and the Ministry of Health to discuss the data and the possible consequences. We exchanged ideas on the risks and impact of MCR-1 on both colistin use in animals and humans in China. Thanks to Newton Funding secured in July we were able to continue these discussions.
A phase III clinical trial, testing whether colistin is effective in a large population, was also underway at the time in China. The outcome of this trial was a big influencing factor in the discussions. The results concluded that colistin is effective for the treatment of serious infections in humans. Using the antibiotic in both health and agricultural sectors would therefore have been counterproductive.
On 26 July the Ministry of Agriculture announced it would withdraw colistin from animal feeds from 1 November. This decision will lead to removal of more than 8000 tonnes of colistin as a growth promoter from the Chinese veterinary sector.
This unprecedented action shows China taking the lead in antimicrobial stewardship with respect to the animal sector. I hope that, by being very open and honest, their decision puts pressure on other countries. The European Medicines Agency has also taken a positive step to update its advice on reducing the use of colistin in European veterinary practices.
We really do need a radical plan for antimicrobial resistance.
Our work highlights the value of international collaboration and the importance of working in partnership with policy-makers. Above everything else we need international accountability and a commitment to implement realistic action plans.
I hope that other countries will follow China’s lead, so that we can try to prolong the effectiveness of colistin as a vital treatment option for highly resistant bacteria.
As told to Isabel Baker
*This research was funded by the National Key Basic Research Program of China and the National Natural Science Foundation of China, with additional support from the MRC (G1100135).
Tim’s Newton funding (MR/P007295/1) was awarded through the Newton Fund AMR-China Partnership Initiative, supported by the MRC, ESRC, BBSRC and the National Natural Science Foundation of China. The Newton Fund is managed by the Department for Business, Energy and Industrial Strategy (BEIS). The fund forms part of the UK government’s official development assistance (ODA).