title: Variable effects of oxytetracycline on antibiotic resistance gene abundance and the bacterial community during aerobic composting of cow manure.
abstract: Livestock manure is often subjected to aerobic composting but little is known about the variation in antibiotic resistance genes (ARGs) during the composting process under different concentrations of antibiotics. This study compared the effects of three concentrations of oxytetracycline (OTC; 10, 60, and 200mg/kg) on ARGs and the succession of the bacterial community during composting. Very similar trends were observed in the relative abundances (RAs) of each ARG among the OTC treatments and the control during composting. After composting, the RAs of tetC, tetX, sul1, sul2, and intI1 increased 2-43 times, whereas those of tetQ, tetM, and tetW declined by 44-99%. OTC addition significantly increased the absolute abundances and RAs of tetC and intI1, while 200mg/kg OTC also enhanced those of tetM, tetQ, and drfA7. The bacterial community could be grouped according to the composting time under different treatments. The highest concentration of OTC had a more persistent effect on the bacterial community. In the present study, the succession of the bacterial community appeared to have a greater influence on the variation of ARGs during composting than the presence of antibiotics. Aerobic composting was not effective in reducing most of the ARGs, and thus the compost product should be considered as an important reservoir for ARGs.
authors.affiliation: College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Xun
authors.initials: X
authors.lastname: Qian
authors.affiliation: College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Sun
authors.affiliation: College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China; Research Center of Recycle Agricultural Engineering and Technology of Shaanxi Province, Northwest A&F University, Yangling, Shaanxi 712100, China. Electronic address: gujie205@sina.com.
authors.forename: Jie
authors.initials: J
authors.lastname: Gu
authors.affiliation: College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Xiao-Juan
authors.initials: XJ
authors.lastname: Wang
authors.affiliation: College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Jia-Jun
authors.initials: JJ
authors.lastname: Sun
authors.affiliation: College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Ya-Nan
authors.initials: YN
authors.lastname: Yin
authors.affiliation: College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Man-Li
authors.initials: ML
authors.lastname: Duan
mesh_terms: D000332:Aerobiosis; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000145:classification / Q000187:drug effects / Q000235:genetics; D002417:Cattle; D000076282:Composting; D004352:Drug Resistance, Microbial / Q000235:genetics*; D005798:Genes, Bacterial; D008372:Manure / Q000382:microbiology*; D010118:Oxytetracycline / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D008372:Manure; D010118:Oxytetracycline
keywords: Aerobic composting; Antibiotic resistance gene; Livestock manure; Oxytetracycline