title: Conjugative multi-resistant plasmids in Haihe River and their impacts on the abundance and spatial distribution of antibiotic resistance genes.
abstract: In this study, five classes of antibiotic resistance genes (ARGs) were quantified in sediment samples of Haihe River, China, with abundance ranging from 1.39 × 104to 1.58 × 1010copies/g dry weight. Meanwhile, antibiotic resistant conjugative plasmids were also isolated from these samples through filter mating assays. In total, 202 transconjugants were isolated and tested for their antibiotic resistance phenotypes, among which 26 different types of conjugative plasmids were observed. The majority of these plasmids showed a multi-resistant phenotype and the most prevalent resistance was tetracycline resistance and sulfonamide resistance. Furthermore, we tested the transfer frequencies of these plasmids, determined their genotypes and then compared the plasmid-borne ARGs with their corresponding abundance in Haihe River. Most of the isolated plasmids exhibited high transfer frequencies to the recipient strain Escherichia coli J53. Plasmids isolated from the urban areas of Haihe River have higher transfer frequencies than the rural areas. Results from comprehensive analysis of plasmid genotypes, ARG abundance and plasmid sequencing confirmed that most of the plasmid-borne ARGs were the dominant genes in the Haihe River. Therefore, conjugative plasmids isolated from the Haihe River plays a crucial role in the dissemination, abundance and spatial distribution of ARGs in Haihe River, especially some unfrequent ARGs like blaGES-1. This study will help to increase the knowledge on the conjugative plasmid-mediated ARG propagation in the environment.
authors.affiliation: Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, China; School of Environmental Science and Engineering, Tianjin University, Tianjin, China.
authors.forename: Bingjun
authors.initials: B
authors.lastname: Dang
authors.affiliation: School of Environmental Science and Engineering, Tianjin University, Tianjin, China. Electronic address: mao@tju.edu.cn.
authors.forename: Daqing
authors.initials: D
authors.lastname: Mao
authors.affiliation: Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, China; School of Environmental Science and Engineering, Tianjin University, Tianjin, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, China. Electronic address: luoy@nankai.edu.cn.
authors.forename: Yi
authors.initials: Y
authors.lastname: Luo
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004352:Drug Resistance, Microbial / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects; D010957:Plasmids / Q000187:drug effects; D045483:Rivers
chemical_list: D000900:Anti-Bacterial Agents
keywords: Antibiotic resistance genes; Conjugative plasmids; Genotypes; Phenotypes; Transfer frequencies