title: High-throughput quantification of antibiotic resistance genes from an urban wastewater treatment plant.
abstract: Antibiotic resistance among bacteria is a growing problem worldwide, and wastewater treatment plants have been considered as one of the major contributors to the dissemination of antibiotic resistance to the environment. There is a lack of comprehensive quantitative molecular data on extensive numbers of antibiotic resistance genes (ARGs) in different seasons with a sampling strategy that would cover both incoming and outgoing water together with the excess sludge that is removed from the process. In order to fill that gap we present a highly parallel quantitative analysis of ARGs and horizontal gene transfer potential over four seasons at an urban wastewater treatment plant using a high-throughput qPCR array. All analysed transposases and two-thirds of primer sets targeting ARGs were detected in the wastewater. The relative abundance of most of the genes was highest in influent and lower in effluent water and sludge. The resistance profiles of the samples cluster by sample location with a shift from raw influent through the final effluents and dried sludge to the sediments. Wastewater discharge enriched only a few genes, namely Tn25 type transposase gene and clinical class 1 integrons, in the sediment near the discharge pipe, but those enriched genes may indicate a potential for horizontal gene transfer.
authors.affiliation: Department of Food and Environmental Sciences, University of Helsinki, Finland antti.karkman@helsinki.fi.
authors.forename: Antti
authors.initials: A
authors.lastname: Karkman
authors.affiliation: Center for Microbial Ecology, Michigan State University, East Lansing, MI, USA.
authors.forename: Timothy A
authors.initials: TA
authors.lastname: Johnson
authors.affiliation: Department of Food and Environmental Sciences, University of Helsinki, Finland.
authors.forename: Christina
authors.initials: C
authors.lastname: Lyra
authors.affiliation: Center for Microbial Ecology, Michigan State University, East Lansing, MI, USA.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Stedtfeld
authors.affiliation: Department of Food and Environmental Sciences, University of Helsinki, Finland.
authors.forename: Manu
authors.initials: M
authors.lastname: Tamminen
authors.affiliation: Center for Microbial Ecology, Michigan State University, East Lansing, MI, USA.
authors.forename: James M
authors.initials: JM
authors.lastname: Tiedje
authors.affiliation: Department of Food and Environmental Sciences, University of Helsinki, Finland.
authors.forename: Marko
authors.initials: M
authors.lastname: Virta
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification*; D001426:Bacterial Proteins / Q000235:genetics*; D024881:Drug Resistance, Bacterial; D022761:Gene Transfer, Horizontal; D032023:Integrons; D012722:Sewage / Q000382:microbiology; D062065:Wastewater / Q000382:microbiology*; D018508:Water Purification / Q000295:instrumentation*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D012722:Sewage; D062065:Wastewater
keywords: qPCR; sewage; sludge