Persistence and risk of antibiotic residues and antibiotic resistance genes

　　Antibiotics arewidely used in mariculture industry, and this study attempts to determine the extent ofwater and sediment pollution by antibiotic residues in 13majormariculture sites in China. Through chemical and molecular biology analysis, the results showed that the total concentrations of sulfonamides and tetracyclines were in the range 62.0–373.8 ng L−1 and 0.2–259.1 ng L−1 respectively in water samples, and in the range 0.19–1.59 ng g−1 dry weight and 3.45–74.84 ng g−1 dry weight respectively, in sediments samples. The occurrence of antibiotic resistance genes (ARGs) was detected in all sites. Compared with the tetracyclines resistance genes, the absolute copy number and relative abundance of the sulfonamides resistance genes were 4.3 times and 2.3 times higher in water and sediment from the mariculture sites, with the dominant resistance genes being sul2. The abundance of sul3 in thewater phasewas significantly correlated with the concentrations of sulfamerazine, while the abundance of sul2 in the sediment phase was significantly with sulfadiazine concentrations. The abundance of tetM in the sediment phase was significantly correlated with the concentrations of oxytetracycline. The findings demonstrate the persistence of antibiotic residues and ARGs in major mariculture sites in Southeast China.
Figure (a): The sampling locations of the major mariculture sites in China. There are site 1 (Tianjin), site 2 (Qingdao), site 3 (Lianyungang), site 4 (Zhoushan), site 5 (Ninghai), site 6 (Wenzhou), site 7 (Ningde), site 8 (Quanzhou), site 9 (Shantou), site 10 (Shenzhen), site 11 (Fangchenggang), site 12 (Haikou) and site 13 (Sanya). (b): Spatial distribution of total antibiotic concentrations in water and sediment samples.
List of relate publications: