title: Seasonal variation and removal efficiency of antibiotic resistance genes during wastewater treatment of swine farms.
abstract: The seasonal variation and removal efficiency of antibiotic resistance genes (ARGs), including tetracycline resistance genes (tetG, tetM, and tetX) and macrolide (ermB, ermF, ereA, and mefA), were investigated in two typical swine wastewater treatment systems in both winter and summer. ARGs, class 1 integron gene, and 16S rRNA gene were quantified using real-time polymerase chain reaction assays. There was a 0.31-3.52 log variation in ARGs in raw swine wastewater, and the abundance of ARGs in winter was higher than in summer. tetM, tetX, ermB, ermF, and mefA were highly abundant. The abundance of ARGs was effectively reduced by most individual treatment process and the removal efficiencies of ARGs were higher in winter than in summer. However, when examining relative abundance, the fate of ARGs was quite variable. Anaerobic digestion reduced the relative abundance of tetX, ermB, ermF, and mefA, while lagoon treatment decreased tetM, ermB, ermF, and mefA. Sequencing batch reactor (SBR) decreased tetM, ermB, and ermF, but biofilters and wetlands did not display consistent removal efficiency on ARGs in two sampling seasons. As far as the entire treatment system is concerned, ermB and mefA were effectively reduced in both winter and summer in both total and relative abundance. The relative abundances of tetG and ereA were significantly correlated with intI1 (p < 0.01), and both tetG and ereA increased after wastewater treatment. This may pose a great threat to public health.
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.|Department of Water Pollution Control Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
authors.forename: Qianwen
authors.initials: Q
authors.lastname: Sui
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.|Department of Water Pollution Control Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
authors.forename: Junya
authors.initials: J
authors.lastname: Zhang
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.|Department of Water Pollution Control Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Tong
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China. mxchen@rcees.ac.cn.|Department of Water Pollution Control Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China. mxchen@rcees.ac.cn.
authors.forename: Meixue
authors.initials: M
authors.lastname: Chen
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China. yswei@rcees.ac.cn.|Department of Water Pollution Control Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China. yswei@rcees.ac.cn.|Institute of Energy, Jiangxi Academy of Sciences, Nanchang, 330096, China. yswei@rcees.ac.cn.
authors.forename: Yuansong
authors.initials: Y
authors.lastname: Wei
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004352:Drug Resistance, Microbial / Q000235:genetics; D000072480:Farms; D005798:Genes, Bacterial; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012621:Seasons; D013552:Swine; D062065:Wastewater
chemical_list: D000900:Anti-Bacterial Agents; D012336:RNA, Ribosomal, 16S; D062065:Wastewater
keywords: Antibiotic resistance genes; Antibiotic resistant bacteria; Biological wastewater treatment; Class 1 integron; Real-time polymerase chain reaction; Swine wastewater