Learnings from the pilot Citizen Science and AMR project

Background Antimicrobial resistance (AMR) is a global societal challenge which can be characterised as a ‘One Health’ problem as it has implications not only for human health but also that of animals, the environment and, ultimately, the economy. Despite the significance of this threat, there remain substantial knowledge gaps in relation to transmission pathways for AMR within the food system, and home-growing is a particularly understudied space. Citizen Science and Antimicrobial Resistance (CSAMR) was a pilot project designed to collate data on the cultivation and food preparation practices of home-growers which could enrich existing knowledge on how AMR bacteria move through the food system. CSAMR sought equally to prove the efficacy of citizen science methodology to contribute to the evidence base in this research area. Methodology CSAMR adopted a collaborative citizen science approach, with participants being involved in multiple stages of the scientific process. Project methods comprised a preand post- project questionnaire, a Question & Answer (Q&A) series and swab collection exercise. The project Q&A series was designed to build participants’ understanding of AMR in order to empower them to co-design and refine the project’s central data collection instrument (swab questionnaire) which they subsequently completed as part of the swab collection exercise. Participants collected swab samples from the surface of home-grown lettuces and submitted them to the research team for analysis. To examine the effects of participants’ food-handling practices, each lettuce was swabbed twice (once before, and once after, preparation for consumption). Although the sampling protocol was stipulated by the team, we gave no instruction on ‘preparation for consumption’ in order to capture data on the diversity of preparation practice. Lettuces were selected for sampling both because their intrinsic qualities made them particularly interesting for this research (as a ‘ready-to-eat’ crop, many of the practices measures which might otherwise mitigate the risk of consuming pathogenic microorganisms do not apply) and for logistical reasons (since lettuces are a widely grown crop this broadened the pool of potential participants and their typical harvest period aligned well with the project timeline). Samples received (n=254) were tested for the presence of selected target bacteria (Escherichia coli, Salmonella and Listeria monocytogenes) which, if detected, were analysed for susceptibility against a range of antimicrobials. These methods were designed to answer the following core research questions: 1) How do people grow and prepare crops at home? 2) Are there home growing or food preparation practices which increase the likelihood of finding AMR bacteria? 3) Can citizen science methods provide quality data helping to fill evidence gaps in antimicrobial resistance research? Key Findings A total of 127 lettuces were swabbed by 84 participants, generating 254 samples for analysis (one sample each pre- and post- preparation for consumption). Target bacteria were detected on 38 (15.0%) of the 254 samples. The most common of our target bacteria was E. coli, which was detected 37 times. Listeria and Salmonella were both detected much less often (6 and 5 times respectively). Interestingly, E. coli was detected more frequently on samples collected after preparation for consumption (n=22) as compared with samples collected pre-preparation (n=15). Statistical analysis of available data yielded no insight into this pattern, with no statistically significant relationship between any of the processing measures undertaken (washing method or drying method) and the detection of E. coli. Out of the 48 instances where target bacteria were detected, 44 cultures (91.7%) were resistant to one or more of the antimicrobial agents tested, with multi-drug resistance (which we have classified as resistance to 3 or more antimicrobials) demonstrated in 28 (58.3%) instances. Statistical analysis provided limited insight into factors associated with the presence of bacteria exhibiting AMR, though possible links with wild/companion animal presence, and the effects the time for which water was standing (e.g. in water butts) were highlighted. This substantiates the importance of using a One Health lens when considering AMR. Factors affecting AMR prevalence suggested by the literature such as manure application were not supported by this study with our small sample size. This warrants further investigation in larger scale studies. Outcomes of and Reflections on Citizen Science The FSA and UKRI required grant recipients to partner and co-create projects with citizens. Some of our team have extensive experience of running citizen science projects, whilst for others it was their first time. All found it a very valuable learning experience, with interesting results. Challenges included the short time frame of the project and budget, along with low attendance at some of our Q&A sessions. Conclusions The FSA should consider running more projects using a citizen science approach as it proved a useful way of collecting data that would not otherwise be easily available, whilst improving participants’ knowledge about AMR. Larger scale projects could investigate different pathogens of interest or employ other techniques such as whole genome sequencing to enable analysis of the microbiome and resistome of samples, thereby improving the evidence base.