Antibiotics and resistance genes in wastewater treatment plants

Abstract

Antibiotics have been discharged into wastewater treatment plants (WWTPs) for decades. As a result, multiple classes of antibiotics have been widely detected in different WWTPs worldwide. The widely applied biological treatment process creates favourable conditions for antibiotic resistance gene (ARG) development and horizontal gene transfer under the sub-inhibitory antibiotic concentrations. So far, six classes of antibiotics, i.e., β-lactams, sulfonamides, quinolones (fluoroquinolones), tetracyclines, macrolides and others have been detected in the influents and effluents from WWTPs worldwide. A big portion of ARGs in natural environments and faecal samples could be detected in WWTPs and the levels of ARGs in WWTPs are comparable to the faecal sources. These results demonstrated that the role of WWTPs as hot spots for the spread of ARGs requires further comprehensive study to develop an integrated strategy to fight the resistance.