Insight into the spatiotemporal distribution of antibiotic resistance genes in estuarine sediments during long-term ecological restoration

• Published in: Journal of environmental management Vol. 335; p. 117472
• Main Authors: Xu, Ming, Huang, Xing-hao, Gao, Peng, Chen, Hao-qiang, Yuan, Quan, Zhu, Yun-xiang, Shen, Xiao-xiao, Zhang, Yan-yan, Xue, Zhao-xia
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.06.2023
• Subjects: Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Anti-Bacterial Agents; Antibiotic resistance genes; Antibiotic-resistant bacteria; China; Drug Resistance, Microbial - genetics; Ecological restoration; Estuary sediment; Genes, Bacterial; Spatiotemporal distribution; China; Ecological restoration; Antibiotic-resistant bacteria; Antibiotic resistance genes; Estuary sediment; Spatiotemporal distribution
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2023.117472

In this study, we aimed to investigate the long-term spatiotemporal changes in hydrodynamics, antibiotics, nine typical subtypes of antibiotic resistance genes (ARGs), class 1 integron gene (intI1), and microbial communities in the sediments of a semi-enclosed estuary during ecological restoration with four treatment stages (influent (#1), effluent of the biological treatment area (#2), oxic area (#3), and plant treatment area (#4)). Ecological restoration of the estuary reduced common pollutants (nitrogen and phosphorus) in the water, whereas variations in ARGs showed noticeable seasonal and spatial features. The absolute abundance of ARGs at sampling site #2 considerably increased in autumn and winter, while it significantly increased at sampling site #3 in spring and summer. The strong intervention of biological treatment (from #1 to #2) and aerators (from #2 to #3) in the estuary substantially affected the distribution of ARGs and dominant antibiotic-resistant bacteria (ARB). The dominant ARB (Thiobacillus) in estuarine sediments may have low abundance but important dissemination roles. Meanwhile, redundancy and network analysis revealed that the microbial communities and intl1 were key factors related to ARG dissemination, which was affected by spatial and seasonal ecological restoration. A positive correlation between low flow velocity and certain ARGs (tetM, tetW, tetA, sul2, and ermC) was observed, implying that flow optimization should also be considered in future ecological restoration to remediate ARGs. Furthermore, the absolute abundance of ARGs can be utilized as an index to evaluate the removal capacity of ARGs by estuarine restoration. [Display omitted] •Effects of ecological restoration on ARG distribution in sediment were investigated.•The sul1, tetA, ermB, ermC and floR were dominant ARGs in the estuary sediments.•Microbial genera in Proteobacteria were dominant ARBs in the estuary sediments.•Microbial communities and intl1 were key factors related to the ARG dissemination.•ARGs dissemination was affected by ecological restoration spatially and seasonally.