Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China.
Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China.
Environ Pollut. 2018 Nov;242(Pt B):1711-1719. doi: 10.1016/j.envpol.2018.07.101. Epub 2018 Jul 30.
Mariculture sediment has been recognized as a major contributor of environmental antibiotic resistance genes (ARGs), which are challenging the treatment of infections worldwide. Both antibiotics and fishmeal are used in aquaculture, and each has the potential to facilitate ARG dissemination, however their combined impact on the sediment resistome and their relative contribution remain unclear. In this study, microcosms were exposed to varying concentrations of tetracycline with or without fishmeal (0.1% wt/wt) for 14 days. Sediment genomic DNA was analyzed using high throughput quantitative PCR and 16S rRNA gene amplicon sequencing to compare the contribution of fishmeal and tetracycline to antibiotic resistomes and bacterial communities in mariculture sediment. Sixty-seven ARGs were detected potentially correlating to resistance for several major antibiotics. Fishmeal, but not the dose of tetracycline, contributed to the significant increase of both ARG abundance and diversity in the sediment. Based on principle coordinate analysis and hierarchical clustering, ARGs were clustered into two groups depending on whether fishmeal was added. Aminoglycoside, macrolide-lincosamide-streptogramin b (MLSb) and tetracycline resistance genes were the most abundant when fishmeal was used, while a significant increase in mobile genetic element (MGE) abundance was also detected (P < 0.05). Meanwhile, bacterial community structures were detected with distinct patterns between the two groups (Adonis, P < 0.05). Using the Mantel test and partial least squares path modeling, we identified that sediment resistomes were significantly correlated with microbial community structures (P < 0.05) which were mainly driven by nutrients in fishmeal. Together our findings suggested that fishmeal plays a more important role than tetracycline in proliferation of ARGs in mariculture sediment. This study may provide new insights into the mitigation of ARG propagation in mariculture operations.
水产养殖沉积物已被认为是环境抗生素抗性基因（ARGs）的主要贡献者，这些基因对全球的感染治疗构成了挑战。抗生素和鱼粉都用于水产养殖，每一种都有可能促进 ARG 的传播，然而，它们对沉积物抗性组的综合影响及其相对贡献尚不清楚。在这项研究中，微宇宙暴露于不同浓度的四环素，或添加或不添加鱼粉（0.1%wt/wt），持续 14 天。使用高通量定量 PCR 和 16S rRNA 基因扩增子测序分析沉积物基因组 DNA，以比较鱼粉和四环素对水产养殖沉积物中抗生素抗性组和细菌群落的贡献。检测到 67 个 ARG 可能与几种主要抗生素的抗性相关。鱼粉而不是四环素的剂量，导致沉积物中 ARG 丰度和多样性的显著增加。基于主坐标分析和层次聚类，根据是否添加鱼粉，将 ARG 聚类成两组。当使用鱼粉时，氨基糖苷类、大环内酯-林可酰胺-链霉菌 B（MLSb）和四环素抗性基因最为丰富，同时也检测到移动遗传元件（MGE）丰度的显著增加（P<0.05）。同时，两组之间检测到细菌群落结构存在明显差异（Adonis，P<0.05）。使用 Mantel 检验和偏最小二乘路径模型，我们确定沉积物抗性组与微生物群落结构显著相关（P<0.05），这主要是由鱼粉中的营养物质驱动的。总之，我们的研究结果表明，鱼粉在水产养殖沉积物中 ARG 增殖方面比四环素发挥更重要的作用。本研究可为水产养殖操作中 ARG 传播的缓解提供新的思路。
