Midwives' experiences of care provision in refugee camps under the guidelines of the ORAMMA project: a qualitative study.

Livestock manure represents a major component of agricultural waste streams in the UK, with over 72 million tonnes collected annually for land application and a further 73 million tonnes deposited directly onto land in England and Wales (). While manure is widely used as an organic fertilizer for arable land due to its high nutrient content (), it is also recognized as a reservoir of antimicrobial-resistant (AMR) bacteria, antimicrobial resistance genes (ARGs), and mobile genetic elements (MGEs) (, ). The land application of untreated or partially treated manure, therefore, represents a potential pathway for the dissemination of AMR into soil ecosystems, surface waters, and the food chain (). A range of manure management strategies is employed to mitigate these risks, including long-term storage in slurry lagoons, composting, and anaerobic digestion (AD) (). These processes can substantially alter microbial community structure and function through physicochemical changes, such as temperature shifts, redox conditions, nutrient availability, and microbial competition (, ). In particular, AD is widely implemented as a waste-to-energy technology and has been shown to restructure microbial communities toward anaerobic consortia dominated by fermentative and methanogenic taxa (, ). However, its impact on ARG dynamics is less clear (). Longitudinal studies of UK dairy slurry systems have demonstrated that manure stores can act as dynamic reservoirs of ARGs and antimicrobial-resistant bacteria, with population stability maintained through continuous input of fresh waste (). Previous studies have produced mixed findings, with some demonstrating reductions in ARG abundance following treatment, particularly with extended storage or thermophilic conditions, while others report persistence or enrichment of specific ARG classes despite reductions in microbial load. For instance, a UK study on dairy slurry storage demonstrated that storing slurry without additional input for at least 60 days reduced the abundance of ARGs before land application (). In contrast, a study in China reported that anaerobic digestion of pig manure did not significantly reduce the ARG burden (). Furthermore, UK-based studies investigating the impact of AD on ARG abundance have focused on human sewage rather than agricultural waste (, ). These inconsistencies are likely driven by differences in feedstock composition, operational parameters (e.g., temperature, retention time, and substrate composition), and the distinction between absolute and relative abundance measures (). Furthermore, ARGs associated with MGEs may persist independently of shifts in taxonomic composition, reflecting the role of horizontal gene transfer and MGE-mediated dissemination in maintaining ARGs across changing microbial communities (). Changes in ARG abundance have also been linked to shifts in microbial community composition, with evidence that bacterial succession during treatment processes can influence ARG profiles through changes in host taxa ().