Ernesto Liebana

The One Health (OH) approach recognizes the interconnectedness of the health of people, animals, plants/crops and ecosystems, and is central to addressing antimicrobial resistance (AMR). The 7th Environmental Dimension of Antimicrobial Resistance Conference (EDAR7), held in Montreal in May 2024, exemplified this approach by convening international experts and stakeholders to discuss AMR research and policy progress. EDAR7 workshop #8 focused on 1) barriers to establishing effective OH AMR research programs, 2) gaps in OH AMR research priorities, and 3) potential solutions/approaches or ‘tools’ to ensure programs develop in accordance with OH principles and generate insightful data that maximizes limited resources. Key workshop outcomes included identifying critical principles for OH AMR research programs and highlighting the pivotal role of sustainable data management strategies. Additionally, the importance of considering AMR policy and risk assessment needs when planning and designing research was emphasized. Discussions explored specific tools and approaches that support the standardized and harmonized collection and analysis of data, and associated challenges of integrating genomics data into current risk assessments and models. Synthesis of the workshop’s discussions outlined critical considerations that interdisciplinary OH AMR research programs and networks should prioritize to enhance the impact of their outputs.

The qualified presumption of safety (QPS) approach was developed to provide a regularly updated generic pre‐evaluation of the safety of microorganisms intended for use in the food or feed chains. Safety concerns identified for a taxonomic unit (TU) are, where possible, confirmed at the species/strain or product level and reflected by ‘qualifications’ which should be assessed at strain and/or product level by EFSA's Scientific Panels. The generic qualification ‘the strains should not harbour any acquired antimicrobial resistance (AMR) genes to clinically relevant antimicrobials’ applies to all QPS bacterial TUs. The different EFSA risk assessment areas use the same approach to assess the qualification related to AMR genes. In this statement, the terms ‘intrinsic’ and ‘acquired’ AMR genes were defined for the purpose of EFSA's risk assessments, and they apply to bacteria used in the food and feed chains. A bioinformatic approach is proposed for demonstrating the ‘intrinsic’/’acquired’ nature of an AMR gene. All AMR genes that confer resistance towards ‘critically important’, ‘highly important’ and ‘important’ antimicrobials, as defined by the World Health Organisation (WHO), found as hits, need to be considered as hazards (for humans, animals and environment) and need further assessment. Genes identified as responsible for ‘intrinsic’ resistance could be considered as being of no concern in the frame of the EFSA risk assessment. ‘Acquired’ AMR genes resulting in a resistant phenotype should be considered as a concern. If the presence of the ‘acquired’ AMR gene is not leading to phenotypic resistance, further case‐by‐case assessment is necessary.

Eurosurveillance.org is the online home of Eurosurveillance, Europe's journal on infectious disease surveillance, epidemiology, prevention and control.

SUMMARY: During 2007–2010, 13 545 confirmed human verocytotoxin (VT)-producingEscherichia coli(VTEC) infections were reported in the European Union, including 777 haemolytic uraemic syndrome (HUS) cases. Clinical manifestations were reported for 53% of cases, 64% of which presented with diarrhoea alone and 10% with HUS. Isolates from 85% of cases were not fully serotyped and could not be classified on the basis of the Karmali seropathotype concept. There is no single or combination of phenotypic or genetic marker(s) that fully define ‘pathogenic’ VTEC. Isolates which contain thevtx2(verocytotoxin 2) gene in combination with theeae(intimin-encoding) gene oraaiC(secreted protein of enteroaggregativeE. coli) andaggR(plasmid-encoded regulator) genes have been associated with a higher risk of more severe illness. A molecular approach targeting genes encoding VT and other virulence determinants is thus proposed to allow an assessment of the potential severity of disease that may be associated with a given VTEC isolate.

The blaESBL and blaAmpC genes in Enterobacteriaceae are spread by plasmid-mediated integrons, insertion sequences, and transposons, some of which are homologous in bacteria from food animals, foods, and humans. These genes have been frequently identified in Escherichia coli and Salmonella from food animals, the most common being blaCTX-M-1, blaCTX-M-14, and blaCMY-2. Identification of risk factors for their occurrence in food animals is complex. In addition to generic antimicrobial use, cephalosporin usage is an important risk factor for selection and spread of these genes. Extensive international trade of animals is a further risk factor. There are no data on the effectiveness of individual control options in reducing public health risks. A highly effective option would be to stop or restrict cephalosporin usage in food animals. Decreasing total antimicrobial use is also of high priority. Implementation of measures to limit strain dissemination (increasing farm biosecurity, controls in animal trade, and other general postharvest controls) are also important.