Toxic effects of long-term dual or single exposure to oxytetracycline and arsenic on Xenopus tropicalis living in duck wastewater

作     者：Jianbin Zhao Xinyan Li Yanbin Xu Yuxin Li Li Zheng Tiangang Luan Jianbin Zhao;Xinyan Li;Yanbin Xu;Yuxin Li;Li Zheng;Tiangang Luan

作者机构：Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for WatershedsInstitute of Environmental and Ecological EngineeringGuangdong University of TechnologyGuangzhou 510006China School of Environmental Science and EngineeringGuangdong University of TechnologyGuangzhou 510006China Analysis and Test CenterGuangdong University of TechnologyGuangzhou 510006China 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2023年第127卷第5期

页      面：431-440页

核心收录：

学科分类：0710[理学-生物学] 082803[工学-农业生物环境与能源工程] 1002[医学-临床医学] 07[理学] 1001[医学-基础医学(可授医学、理学学位)] 08[工学] 0828[工学-农业工程] 0713[理学-生态学] 

基　　金：supported by the National Natural Science Foundation of China(No.41977340) the Key-Area Research and Development Program of Guangdong Province(No.2020B1111350003). 

主　　题：Duck wastewater Xenopus tropicalis Inhibition Hepatotoxicity Gut microbiota 

摘      要：Direct discharge of aquaculture wastewater may have toxic effects,due to the presence of heavy metals,antibiotics,and even resistant pathogens,but little attention has been given.Here,tanks simulating a wild ecosystem were built to study the effects of long-term exposure to duckwastewater containing oxytetracycline(OTC)and/or arsenic(As)on the growth,physiological function,and gut microbiota evolution of Xenopus tropicalis.The results showed that duck wastewater had no apparent impact on X.tropicalis,but the impact increased significantly(P0.05)with exposure to OTC and/or As,especially the impact on body weight and growth rate.Biochemical indicators revealed varying degrees of oxidative stress damage,hepatotoxicity(inflammation,necrosis,and sinusoids),and collagen fibrosis of X.tropicalis in all treated groups after 72 days of exposure,which indirectly inhibited X.tropicalis growth.Moreover,16S rDNA amplicon sequencing results showed that the gut microbiota structure and metabolic function were perturbed after chronic exposure,which might be the leading cause of growth inhibition.Interestingly,the abundance of intestinal resistance genes(RGs)increased with exposure time owing to the combined direct and indirect effects of stress factors in duck wastewater.Moreover,once the RGs were expressed,the resistance persisted for at least 24 days,especially that conferred by tetA.These results provide evidence of the toxic effects of DW containing OTC(0.1–4.0 mg/L)and/or As(0.3–3.5μg/L)on amphibians and indicate that it is vital to limit the usage of heavy metals and antibiotics on farms to control the biotoxicity of wastewater.