Editorial: The Environmental Dimension of Antibiotic Resistance

Editors: Tong Zhang, Keiji Fukuda, Edward Topp, Yong-Guan Zhu, Kornelia Smalla, James Tiedje and D. G. Joakim Larsson This Thematic Topic on the Environmental Dimension of Antibiotic Resistance was launched after the 5th International Symposium on the Environmental Dimension of Antibiotic Resistance (EDAR5). The symposium was organized by The University of Hong Kong (HKU) and held on its campus from June 9 to 14, 2019. Antibiotic resistance is an increasingly recognized global challenge that is threatening human and animal health, food security, and the global economy. The magnitude and fundamental importance of this challenge has been widely recognized from academic scientists, the health, agriculture and food sectors, the pharmaceutical industry, and governments to the general public. Effective policies and actions to combat antibiotic resistance depend on better understanding this problem. This includes factors driving the development of antibiotic resistance, such as current antibiotic usage practices in different sectors, the global scope and nature of the problem, and the most effective mitigation and stewardship practices. The role of the environment in antimicrobial resistance (AMR) has been listed by the United Nations Environment Program report ‘Frontiers 2017: Emerging Issues of Environmental Concern’ as the first of six emerging issues of concern. EDAR1 was held in Canada in 2012 and catalyzed international efforts to address the environmental aspect of this problem. This momentum continued and grew with EDAR2, 3, and 4 held in China, Germany and the United States, respectively. Over these conferences, the scope and depth of discussion has grown and become more comprehensive, encompassing all critical environmental aspects. In particular, environmental aspects are now embedded firmly in the One Health continuum of human health, animal health and the environment. In general, international and national guidance on AMR action plans have embraced the One Health Framework. EDAR5 reflected global concern over the emergence and spread of antibiotic-resistant human pathogens, and recognition that the environment is a major reservoir and source for resistance genes. There were 350 registrants from 30 countries, who contributed 229 posters and 70 oral presentations. Participants also joined one of three roundtable discussion sessions related to the theme of ‘Standardized Procedures for Large Surveys and Prioritising Action’. The three discussion topics were: (i) Standardized procedures for large surveys of antibiotic residues, ARGs and their transferability in the agro-ecosystem, (ii) Standardized procedures for large surveys of antibiotics and ARGs in the aquatic environment; and (iii) Prioritising action on environmental AMR (co-organized by HKU and Wellcome Trust Foundation). Each EDAR meeting has revealed considerable progress in this broad field and led to rapid dissemination of new findings, ideas, needs and mitigation strategies to international researchers, practitioners and regulators. The following summarizes the themes of the 17 research articles in this issue and gives a sense of the breadth of EDAR5. Themes included water/sediment (Di Cesare et al. 2020), biofilm (Jorge et al. 2019), soil (Dungan et al. 2019), human fecal microbiota (Scaccia et al. 2020) and human gut (Gutierrez et al. 2020) as major habitats. Two papers concerned the microbiota of flies (Ourry et al. 2020; Poudel et al. 2020) and one was about changes to the resistome during anaerobic co-digestion (Kanger et al. 2020). Four papers concerned pathogenic bacterial isolates (Camiade et al. 2020; Henriot et al. (2019); Jeamsripong et al. 2020; Silva et al. 2020; Ullmann et al. 2020). A total of two papers studied horizontal antibiotic resistance gene transfer, one studied HGT in biofilm (Abe et al. 2020) and one covered phages (Stekel et al. 2020). One paper focused on an online ARG search platform (Zhang et al. 2020). Similar to the observations in the Thematic Issue of EDAR4 (https://academic.oup.com/femsec/pages/edar_2018), these papers assessed antibiotic resistance genes of pathogens isolated from environment, which are more directly related to human risk. However, there still is a relative lack of papers on quantitative risk assessment based on the knowledge of ecological dimensions of antibiotic resistance, and this is hindering a much needed shift from the description of resistance genes in the environment to determination of the processes contributing most to risk, what is feasible to reduce risk and thus what actions are of highest priority to reduce environmental risk. We are confident that important scientific developments, including more research about risk assessment, will occur in the years to come, and much of this ongoing development will be presented at EDAR6, to be held in Gothenburg, Sweden from May 29 to June 3, 2022. We thank the special editors who were appointed to oversee the review of all submitted papers along with some of the regular FEMS Microbiology Ecology editors. The EDAR-5 meeting received financial support from the Environment and Conservation Fund of Hong Kong, Center for Water Technology and Policy (The University of Hong Kong), WYNG Foundation, Wellcome Trust Foundation, and Resistomap Oy. None declared. Search for other works by this author on: Oxford Academic, PubMed, Google Scholar