Transition of antimicrobial resistome in wastewater treatment plants: impact of process configuration, geographical location and season

Antimicrobial resistome in wastewater treatment plants was investigated via shotgun metagenomic analysis over a variety of geographical locations, seasons, and biological treatment configurations. The results revealed that the transition of the antimicrobial resistome occurred at two locations during wastewater treatment, which resulted in a distinctive antimicrobial resistome in influent wastewater, activated sludge, and treated effluent. The antimicrobial resistome in influent wastewater was characterized by a high abundance of antibiotic resistance genes (ARGs) on clinically important drugs, whereas sludge retained a higher abundance of multidrug ARGs associated with efflux pump. Seasonality was the primary factor affecting antimicrobial resistome in influent wastewater, which partially succeeded to the subsequent resistome of activated sludge and treated effluent. Importantly, some ARGs on clinically important drugs in influent wastewater passed through the biological treatment to be discharged in the treated effluent, except in the membrane bioreactor process.

Automated summary

The study investigated the antimicrobial resistome in wastewater treatment plants using shotgun metagenomic analysis. The results showed that there were two locations where the transition of the resistome occurred during wastewater treatment, resulting in a distinctive resistome in influent wastewater, activated sludge, and treated effluent. The resistome in influent wastewater was characterized by a high abundance of antibiotic resistance genes (ARGs) on clinically important drugs, while sludge retained a higher abundance of multidrug ARGs associated with efflux pump. Seasonality was the primary factor affecting the resistome in influent wastewater, which partially influenced the subsequent resistome of activated sludge and treated effluent. Importantly, some ARGs on clinically important drugs in influent wastewater passed through the biological treatment to be discharged in the treated effluent, except in the membrane bioreactor process.