Fish are poor sentinels for surveillance of riverine AMR

This study investigates the potential of fish as sentinels for monitoring antimicrobial resistance (AMR) pollution in rivers impacted by wastewater treatment plants (WWTPs). Two riverine fish species, Brown trout and European bullhead, were sampled up- and downstream a German WWTP. The fish’s microbiomes mirrored changes in river water and sediment, with significant shifts in bacterial community composition. However, fish-associated resistomes were less responsive to ARG abundances, suggesting that other species are better suited for surveillance efforts. The study underscores the complexity of using wildlife as indicators for environmental AMR pollution.