Investigation of antibiotic-resistant bacteria in seafood products and risk of exposure to these by consumers in the UK

A large amount of seafood consumed in the UK are imported from countries outside the EU, where the use of antibiotics is often poorly regulated. In the UK -similarly to other EU countries-, there is no national surveillance of AMR in seafood products; the extent of AMR in seafood is currently unknown. This could be a public health risk as seafood often is consumed undercooked or raw. This study aims to investigate the occurrence of ARGs in seafood and assess the risk of exposure of British consumers.
Our objectives are: 1) to determine the prevalence of ARGs at retail level; 2) to investigate the level of similarity between ARGs from seafood and human clinical isolates to generate hypothesis for potential AMR exposure of consumers through seafood; and, 3) to assess the persistence of ARGs from harvest until the moment of consumption.
Methods. A systematic review will be conducted by the PhD candidate to explore ARGs isolated from seafood products in the food chain in different countries. A probabilistic sampling of a variety of domestic and imported seafood items at retail level will performed in the south of England. Fifty samples of each of seafood product (e.g., imported versus domestically produced, frozen versus fresh items, 'ready-to-eat' products of fish and shellfish) will be obtained at post-harvest level to estimate a prevalence of 50% of ARGs, with a precision of 14% and a 95% confidence level. Multiplex PCR will be used to investigate the presence of ARGs. Isolates will be catalogued and stored for further sequencing (i.e., WGS) if ARGs of public health interest are detected. Similarities between ARGs from seafood (and potentially other food sources) and human clinical isolates will be explored. Human isolates data will be obtained through publicly available foodborne disease surveillance data (i.e. Public Health England and/or European Food Safety Authority's surveillance annual reports in zoonotic and indicator bacteria from humans, animals and food) and Whole Genome Sequencing (WGS) databases. This assessment will be used to generate hypothesis on potential exposure and burden of foodborne disease. Probabilistic models will be used to simulate the impact of conservation and preparation methods in the survival of bacterial strains and persistence of ARGs in seafood products from post-harvest onwards and likely exposure of British consumers. The findings of this project will help to inform the discussion of policy-makers regarding the potential food safety risks associated with AMR in seafood.