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.

海水养殖沉积物已被认为是环境抗生素抗性基因（ARG）的主要贡献者，这对全世界感染的治疗提出了挑战。水产养殖中同时使用了抗生素和鱼粉，每种都具有促进ARG传播的潜力，但是它们对沉积物抗药性组的综合影响及其相对贡献仍不清楚。在这项研究中，微观世界暴露于有或没有鱼粉（0.1％wt / wt）的不同浓度的四环素中14天。使用高通量定量PCR和16S rRNA基因扩增子序列分析了沉积物基因组DNA，以比较鱼粉和四环素对海水养殖沉积物中抗生素抗药性和细菌群落的贡献。检测到67种ARGs可能与几种主要抗生素的耐药性相关。鱼粉而不是四环素的剂量导致沉积物中ARG丰度和多样性的显着增加。基于原理坐标分析和层次聚类，根据是否添加鱼粉将ARG分为两组。当使用鱼粉时，氨基糖苷，大环内酯-林可酰胺-链霉菌素b（MLSb）和四环素抗性基因最丰富，同时还检测到流动遗传元素（MGE）的丰度显着增加（根据是否添加鱼粉，将ARGs分为两组。当使用鱼粉时，氨基糖苷，大环内酯-林可酰胺-链霉菌素b（MLSb）和四环素抗性基因最丰富，同时还检测到流动遗传元素（MGE）的丰度显着增加（根据是否添加鱼粉，将ARGs分为两组。当使用鱼粉时，氨基糖苷，大环内酯-林可酰胺-链霉菌素b（MLSb）和四环素抗性基因最丰富，同时还检测到流动遗传元素（MGE）的丰度显着增加（P  <0.05）。同时，两组之间的细菌群落结构具有明显的差异（Adonis，P  <0.05）。使用Mantel检验和偏最小二乘路径模型，我们确定了沉积物抵抗力与微生物群落结构显着相关（P  <0.05），微生物群落结构主要由鱼粉中的养分驱动。我们的研究结果共同表明，鱼粉在海水养殖沉积物中ARGs的增殖中比四环素更重要。这项研究可能为减轻海水养殖操作中ARG的传播提供新的见解。