Determination of antibiotic resistance genes in a WWTP-impacted river in surface water, sediment, and biofilm: Influence of seasonality and water quality

Many pathogenic bacteria are adapted to live in aquatic habitats, which makes rivers possible sources and spread pathways of antibiotic resistance, since they usually receive effluents from wastewater treatment plants (WWTP), possibly containing residues also antibiotic-resistant bacteria. This study investigates different monitoring strategies identify the occurrence rivers. We analyzed presence 13 resistance genes (ARGs) seven gene markers for facultative (FPB) with qPCR sampling sites upstream downstream a small WWTP Southern Germany. Five campaigns were conducted February June 2019. Surface water, sediment, biofilm samples analyzed. The was collected an artificial sampler placed river. blaTEM, ermB, tetM, sul1 detected all results showed there previous background river, but water quality river influenced concentration ARGs FPB. Genes representing against strong or last-resort antibiotics, such as mecA, blaCMY-2, blaKPC-3, mcr-1, multidrug detected, mainly WWTP. Downstream WWTP, ARG FPB correlated ammoniacal nitrogen, while turbidity, suspended solids, seasonal factors UVA radiation macrophytes. Biofilm presented higher abundances efficient allowed collect biofilms specific periods, helped patterns.