Environmental antibiotic resistance is a major threat to human and veterinary health and a key issue addressed by the European One Health Action Plan Against Antimicrobial Resistance. City sewers shelter rich and diverse bacterial communities that are continuously exposed to antibiotic residues from human excreta, thus becoming a reservoir of resistance. Predicting the risk of antibiotic resistance evolution in city sewers requires a comprehensive understanding of the dynamics and evolution of wastewater bacterial communities faced to such exposition. However, sewers are complex environments and contain multiple abiotic factors, which may act in nonadditive ways. In addition, interactions between species within communities affect growth and consequently competition, through both density- and frequency-dependent processes. By changing the competitive ability of variants, such as antibiotic resistant phenotypes, interspecies interactions also change evolutionary processes.

DEAR-Waste aims at understanding the dynamics of communities and

antibiotic resistance evolution in city sewers,

together with establishing wastewater as a model system

for fundamental studies on community dynamics and evolution.