One Health Drivers of Antibacterial Resistance in Thailand Antibacterial Resistance (ABR) is a significant source of excess mortality in Overseas Development Assistance (ODA) countries and constitutes a major, increasing threat to wellbeing and economic development. Antimicrobial Resistance (AMR), predominantly ABR, is estimated to have caused 38,000 deaths and an economic loss of 1.2 billion US$ in Thailand in 2010. Because of good record keeping and surveillance, Thailand has been used as an exemplar for characteristics of ABR in ODA countries. ABR is common in human, environmental and animal bacterial isolates. However, ABR has mostly been studied separately in discrete sectors (e.g. hospital patients or poultry). The key drivers of ABR relevant to human health cannot be pinpointed in this way because the selection and transmission of ABR results from interactions between humans, animals, and the environment. A "One Health" approach to the problem is required.  During this consortium project, we will study the Enterobacteriaceae family bacteria Klebsiella pneumoniae (Kp) and Escherichia coli (Ec), which reside in the human and animal gut, are common in environments contaminated with faeces, are are considered a significant threat to human health in Thailand. They are commonly carbapenem- and/or 3rd-generation cephalosporin-resistant (3GCR), which are drugs commonly used for serious infections. Carbapenem-resistant Enterobacteriaceae (CRE) are also recognised by WHO as one of the highest priority pathogens globally for which new ABs are urgently needed. Ec and Kp cause a range of infections in hospitalized patients (e.g. surgical site, intra-abdominal, pneumonia, sepsis) and serious community-acquired infections (e.g. complicated urinary tract infection, pyogenic liver abscess, meningitis). The prevalence of 3GCR Kp and Ec in human infections in Thailand has been increasing from less than 10% in 1999 to 50% in 2016, and of carbapenem-resistant Kp from none prior to 2010 to 10%-20% in 2016.  Our consortium's vision is to build a holistic picture of the drivers of ABR in Thailand and to use this information to benefit the Thai people, and as an exemplar for other ODA countries.  The term "driver" may refer to: 1) a material condition or substance, such as a chemical (e.g. an Antibiotic), which, at a particular concentration, selects for the increased prevalence of ABR bacteria; 2) an action, such as exposing bacteria to that chemical by taking an antibiotic; or 3) a socioeconomic condition or circumstance which accounts for that action (e.g. the economic necessity to keep working in the face of illness). A full understanding of ABR drivers at every level is important for the design of effective and appropriate interventions to limit ABR. Hence, this interdisciplinary consortium will investigate them all.  Our study area will be the Mae Klong-Ta Chin Basin, which covers an area of 80x80 km in the central and western part of Thailand. This is the area where the Mae Klong and Ta Chin rivers run from their mountain sources along the Thai-Myanmar border (Mae Klong river) and upper central Thailand (Ta Chin river) down to the Gulf of Thailand. The study area includes districts spread over five provinces (Karnchanaburi, Ratchaburi, Samut Songkram, Samut Sakorn and Nakornprathom). Both rivers enter the study site and run through areas where there are numerous factories, animal farms, rice fields, fruit orchards and communities, allowing multiple possible drivers to be considered in our work.  Our work will run alongside Thailand's National Strategic Plan on AMR, giving us a perfect opportunity to embed our findings in annual reviews of the Strategic Plan, influencing policy and having a relatively short term and direct impact on human health in Thailand. Our engagement and stakeholder activities will also facilitate dissemination of our findings into other countries within the same global region, and comparisons with other projects across the globe will yield added value. The Global Challenges Research Fund (GCRF) supports cutting-edge research to address challenges faced by developing countries. The fund addresses the UN sustainable development goals. It aims to maximise the impact of research and innovation to improve lives and opportunity in the developing world.