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The China Forum seminar on Wednesday 21 February 2024 was delivered by Professor (Director of Biology, , and Professor of Medical Microbiology, , ).

Professor Walsh’s research is focused on elucidating the mechanism by which microbes become immune to antibiotics (i.e. ‘anti-microbial resistance’). His research attempts to identify new animal-only antibiotics, develop compounds for new classes of human-only antibiotics, map the burden of AMR globally and influence public policy towards AMR. China is one of the world’s largest consumers of antimicrobials for humans and the largest user for animals. As incomes improve in developing countries, the proportion of meat in the average diet increases and this will drive tremendous growth in the animal husbandry industry. Professor Walsh explained his discovery of the gene MCR-1, which confers resistance to colistin, a last-resort antibiotic for multi-drug resistant gram-negative infections, including pneumonia. Prior to his discovery of MCR-1 in 2015, China used 8,000 tonnes of colistin annually in agricultural settings. Shortly after this discovery, China banned the domestic use of colistin in animals, leading to a measurable reduction in the presence of the MCR-1 resistance gene in chicken and pig populations by 2017.

Professor Walsh then explained his research into transfer mechanisms of AMR, which was undertaken jointly by Oxford and Fuzhou Universities in a hospital setting in Fuzhou. AMR can develop out of a pool of microbes after the susceptible strains are destroyed and resistant strains survive and replicate. AMR can also spread through the exchange (‘conjugation’) of plasmids, which are small ring-shaped double-stranded molecular structures of genetic material that can be transferred between microbes. Professor Walsh’s research in Fuzhou showed that plasmids that cause AMR can be transferred across a spectrum of microbial species and therefore a range of diseases. For example, it was discovered that resistance to carbapenem, a broad-based antibiotic used in cases of severe infection in humans, can spread from e-coli to enterococcus bacteria, thus rendering the problem of AMR to be much more wide-ranging than previously thought. Further research into the effects of pollution and climate change on AMR also revealed unsettling results, particularly with respect to waste plastics, where a mechanism has been discovered that appears to increase significantly the transfer of AMR in bacteria exposed to water-based waste plastic. Professor Walsh concluded his lecture by elucidating the importance of proper diagnosis in the prescription of antibiotics and control of AMR, and the economic factors at play. Diagnostic equipment is currently produced by a global duopoly, which results in high prices for consumables and analysis kits. Competition from Chinese firms could help to lower the price of diagnostics in lower income countries.

The Q&A session included the following issues: the extent to which plastics contribute to the spread of AMR; market failure in the development of new antibiotics and the role that China might play in resolving this problem; the spread of AMR across different species of microbes and what this means for disease; the influence of Western IP protection on the supply of antibiotics; the extent of deaths attributable to AMR; how the impact of mortality from AMR can be better communicated to policy makers and the general public.

Professor Tim Walsh has been studying antimicrobial resistance (AMR) mechanisms for over 25 years, and publishes regularly in Nature and Lancet journals. Notably, in his career he has discovered and named two of the most notorious antibiotic resistant genes – NDM-1 and MCR-1. His work also helped discover the mobile tigecycline gene (tetX variant).   

Professor Walsh is director of BARNARDS, a Gates Foundation project on AMR, prospectively examining the burden of neonatal sepsis in Pakistan, India, Bangladesh, Rwanda, South Africa, Nigeria (Abuja and Kano) and Ethiopia. Follow up programs include assessing the risks of still- born infants and maternal care in sub-Sahara Africa and assessing the impact of access to affordable antibiotics. Studies in Pakistan include the role of insects in post-surgical infections and the unfortunate global trade of colistin in agriculture. Walsh was PI of DETER-XDR-CHINA, a study examining the spread and burden of AMR in public health sectors and hospitals in 30 provinces in China. He was also PI of CUT-SEC, a ‘one-health” project in China and Thailand. In addition to the above, he heads up a Wellcome Trust study examining the international impact of COVID on AMR.

In 2020 he moved to University of Oxford and co-established the Ineos Oxford Institute of Antimicrobial Research (£100M gift from Ineos) where he is Director of Biology. As part of the Institute his key interests are: (1) The use of antimicrobials in animals and its impact of human clinical failures; (2) The drivers of AMR across all “one-health” sectors; (3) Causes and management of AMR neonatal sepsis and stillbirths in low- and middle-income countries (LMICs) and (4) The clinical and economic burden of AMR in LMICs.

Professor Walsh has been appointed to the Fleming Fund expert advisory panel – a rolling UK government AMR capacity building program in LMICs. He is also advisor to the Foundation Merieux AMR teaching program and is a member of the WHO Strategic and Technical Advisory Group for Antimicrobial Resistance (STAG-AMR).

In addition to the above he holds an honorary chair at the China Agricultural University in veterinary microbiology and is advisor to the ENABLE 2 program on drug discovery. In 2020, he was awarded an OBE for “Microbiology and International Development” and in 2022 was awarded his DSc (University of Bristol).