A model has been developed to help the Food Standards Agency (FSA) assess the risk for consumers from AMR associated bacteria in food.

Antimicrobial resistance (AMR) is where microorganisms survive antimicrobial treatments such as antibiotics and make infections more difficult to treat.

To test the tool on various pathogens and different food production chains, E. coli and Campylobacter and the chicken and lettuce supply chains were used. Model outputs were consistent with the existing scientific literature and provided reliable results. Their use will allow better prioritization of risk management interventions.

Production chains were investigated by a literature review and stakeholder workshop with UK poultry and lettuce industry representatives led by project partners Ausvet Europe and SAFOSO.

The presence of antimicrobial resistant genes (ARGs) in food can amplify the burden of foodborne AMR in the UK population.

Produce and meat sector focus
Leafy greens might be contaminated with AMR bacteria at pre-harvest through contaminated manure, soil or wildlife vectors and at post-harvest during processing or food preparation. Meat is one of the main carriers of AMR bacteria. Contamination might occur at the slaughterhouse through cross-contamination or at consumer level from inappropriate food handling.

The challenge was to develop flexible modules that can be used off the shelf and adapted depending on the bacteria and supply chain.

Two combinations of microorganisms and ARGs were selected to test and validate the models, which were based on existing approaches. Four modules included all critical production steps and the most popular intervention used in the food chain.

The model allows new microorganisms and genes to be tested plus attributes and steps in the supply chain to be changed. New information from whole genome sequencing can also be added as well as specific interventions such as rapid surface chilling.

For some variables used in the tool there was scarce availability of data, especially for a number of AMR-related parameters.

“Data availability is likely to be a major limitation for using the modelling framework to assess the risk of consumer exposure to specific AMR genes,” said the report.

The model also assumes the bacterial load on a contaminated product is homogeneously distributed which may not be the case. Researchers said the choice to not include a parameter related to “part of carcass” aimed to simplify the data collection process for future users.

Ongoing AMR survey
The FSA has also commissioned an AMR survey in chicken and turkey meat collected at retail in the UK from January to December 2022. This work involves collecting 300 chicken and 300 turkey meat samples with planned completion by March 2023.

It will fill evidence gaps, provide continued monitoring for E. coli and Campylobacter as well as a baseline for Salmonella surveillance. This will help determine if these meats pose a risk to public health in relation to AMR and allow monitoring of trends over time.

Analysis will require isolation and enrichment of E. coli from all meat samples, prior to testing for AMR, specifically Extended Spectrum Beta Lactamases (ESBLs), AmpC and Carbapenemase-producing E. coli. Analysis for colistin resistance and the colistin resistant mcr genes will also be included.

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