The current linear economic model of production and consumption leads to significant resource depletion and waste accumulation, highlighting the urgent need to transition toward a circular economy. In this context, recovering resources by using treated organic waste and reclaimed water in agriculture offers great potential for recycling nutrients and water. However, these practices also carry risks by potentially spreading antibiotic-resistant pathogens, and their associated virulence genes and antibiotic resistance genes, which worsen the global health crisis. While efforts exist to control antimicrobial resistance, the role and fate of virulence genes remain largely unexplored. This project aims to address critical knowledge gaps about how new resource recovery technologies affect the dissemination and mitigation of virulence genes and antibiotic resistance genes. Specifically, the project pursued the following objectives:
1) Characterize the presence, co-occurrence, and persistence of virulence and antibiotic resistance genes throughout wastewater treatment plants, examining how different treatment processes influence their removal or dissemination.
2) Evaluate the effectiveness of solid waste treatment technologies (e.g. composting and anaerobic digestion) in reducing virulence and antibiotic resistance genes, and study the risks linked to their presence and transfer after applying treated biosolids to agricultural soils.
3) Investigate the horizontal gene transfer processes that allow virulence and antibiotic resistance genes to move from microbial communities in treatment systems to environmental bacteria.
By understanding the fate of these genes during waste and wastewater treatment and their potential impact on ecosystems, this project has helped to develop safer and more effective strategies to manage health risks while promoting sustainable resource recovery.
