The population growth associated with urbanization and climate change, increase pressures on regional water resources and the need for the (re)use of wastewater for irrigation of agricultural lands worldwide. At the same time, the spread and evolution of antibiotic resistant bacteria in the environment, animals and people is one of the most important threats to global human health. It is estimated that more than 800 million farmers are involved in urban peri-urban agriculture in the world, out of which 200 million rely on raw or diluted wastewater for irrigation. Vegetable crops, because of their higher yield potential, low cost of production, higher nutritional value, and high prices in urban market owing to the increasing population in urban cities, are the most commonly irrigated crops with wastewater in low and middle-income countries. In this project, we used metagenomics to investigate microbial patterns, the presence of pathogenic bacteria, plasmids and antibiotic resistance genes in wastewater used for urban agriculture in two African countries (Burkina-Faso and Cameroon). The aim was to evaluate the epidemiological risks associated with the use of wastewater for urban agriculture in these countries, in terms of spreading bacterial drug resistance.
• The first objective was to conduct representative sampling of wastewaters and
soils with samples that represented all the investigated areas.
• The second objective was to assess physical-chemical characteristics of collected
samples, and pollution by selected antibiotics. This was to evaluate the influence of abiotic factors and antibiotic pressure on the dynamics of antibiotic-resistant bacteria and antibiotic-resistance genes.
• The third objective was to identify the underlying commonalities / similarities in
antibiotic resistant bacteria community structures in wastewaters and soils. This information was to further allow understanding of the influence of wastewater irrigation on the potential establishment of bacterial phyla, which are known to include strains that can act as facultative or opportunistic human pathogen.
• The fourth objective was to identify antibiotic resistant genes and evaluate their
abundance in wastewaters and soils. That was to allow a description of antibiotic resistant genes of medical interest, their taxonomic position, and development under continuous pollution.
• The fifth objective was to identify plasmid amplicons of clinical relevance. This was to give a broader insight into mobile genetic elements involved in the dissemination of transmissible antibiotic resistance genes.