title: Long-Term Nickel Contamination Increases the Occurrence of Antibiotic Resistance Genes in Agricultural Soils.
abstract: Heavy metal contamination is assumed to be a selection pressure on antibiotic resistance, but to our knowledge, evidence of the heavy metal-induced changes of antibiotic resistance is lacking on a long-term basis. Using quantitative PCR array and Illumina sequencing, we investigated the changes of a wide spectrum of soil antibiotic resistance genes (ARGs) following 4-5 year nickel exposure (0-800 mg kg-1) in two long-term experimental sites. A total of 149 unique ARGs were detected, with multidrug and β-lactam resistance as the most prevailing ARG types. The frequencies and abundance of ARGs tended to increase along the gradient of increasing nickel concentrations, with the highest values recorded in the treatments amended with 400 mg nickel kg-1soil. The abundance of mobile genetic elements (MGEs) was significantly associated with ARGs, suggesting that nickel exposure might enhance the potential for horizontal transfer of ARGs. Network analysis demonstrated significant associations between ARGs and MGEs, with the integrase intI1 gene having the most frequent interactions with other co-occurring ARGs. The changes of ARGs were mainly driven by nickel bioavailability and MGEs as revealed by structural equation models. Taken together, long-term nickel exposure significantly increased the diversity, abundance, and horizontal transfer potential of soil ARGs.
authors.affiliation: State Key Laboratory of Urban and Regional Ecology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China Faculty of.|Veterinary and Agricultural Sciences, The University of Melbourne , Parkville, Victoria 3010, Australia.
authors.forename: Hang-Wei
authors.initials: HW
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Urban and Regional Ecology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China Faculty of.
authors.forename: Jun-Tao
authors.initials: JT
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Urban and Regional Ecology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China Faculty of.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: Veterinary and Agricultural Sciences, The University of Melbourne , Parkville, Victoria 3010, Australia.
authors.forename: Xiu-Zhen
authors.initials: XZ
authors.lastname: Shi
authors.affiliation: National Soil Fertility and Fertilizer Effects Long-term Monitoring Network, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences , Beijing 100081, China.
authors.forename: Yi-Bing
authors.initials: YB
authors.lastname: Ma
authors.affiliation: Veterinary and Agricultural Sciences, The University of Melbourne , Parkville, Victoria 3010, Australia.
authors.forename: Deli
authors.initials: D
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Urban and Regional Ecology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China Faculty of.|Veterinary and Agricultural Sciences, The University of Melbourne , Parkville, Victoria 3010, Australia.
authors.forename: Ji-Zheng
authors.identifier: 0000-0002-3294-102X
authors.initials: JZ
authors.lastname: He
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004352:Drug Resistance, Microbial / Q000235:genetics; D005798:Genes, Bacterial / Q000187:drug effects; D009532:Nickel; D012987:Soil
chemical_list: D000900:Anti-Bacterial Agents; D012987:Soil; D009532:Nickel