Treated wastewater irrigation promotes the spread of antibiotic resistance into subsoil pore-water

In the present study, we investigated impact of treated wastewater (TWW) irrigation on prevalence antibiotic resistance genes (ARGs) in subsoil pore-water, a so-far under-appreciated matrix. We hypothesized that TWW increases ARG pore-water. This hypothesis was tested using multiphase approach, which consisted sampling percolated pore-water from lysimeter-wells real-scale TWW-irrigated field, operated for commercial farming practices, and controlled, laboratory microcosms irrigated with freshwater or TWW. monitored abundance six selected ARGs (sul1, blaOXA-58, tetM, qnrS, blaCTX-M-32 blaTEM), intI1 gene associated mobile genetic elements an indicator anthropogenic pollution bacterial (16S rRNA gene) by qPCR. The load pore water independent both, intensity field study type microcosms. Among sul1 exhibited constantly higher relative abundances. Their further positively correlated increasing intensity. Controlled microcosm experiments verified observed results: several genes, including intI1, increased significantly when irrigating compared to irrigation. Overall, promoted spread while maintained. combined results agricultural controlled lab indicate dissemination various subsurface environments needs be taken into account during scenarios.