摘要

       抗生素抗性基因 (ARG) 在全球海水养殖沉积物中普遍存在，它们的存在是抗生素使用背景下的一个问题。尽管大量鱼粉已被释放到沉积物中，但鱼粉在 ARG 传播中的作用仍不清楚。在这项研究中，研究了代表性鱼粉产品中的高通量 ARG 谱以及鱼粉对沉积物抵抗组的影响。在五种鱼粉产品中共检测到 132 种独特的 ARG 和 4 种移动遗传元件 (MGE)。添加鱼粉后海水养殖微观世界沉积物中的 ARG 丰度和多样性显着增加，并且 ARG 模式的趋势与沉积物中的常驻细菌群落相关（P < 0.05）。鱼粉DNase处理去除了总ARGs的84.3%后，鱼粉中剩余的营养物质增加了微观沉积物中ARGs的相对丰度，但没有增加其多样性。我们的研究首次揭示了鱼粉本身是 ARGs 的主要储存库，鱼粉中营养物质引起的细菌群落变化是形成海水养殖微观沉积物中抗性组的主要驱动力。我们的研究结果提醒人们注意以前未察觉到的鱼粉接收生态系统中 ARG 传播的风险。

       Antibiotic resistance genes (ARGs) are globally prevalent in mariculture sediment, and their presence is an issue of concern in the context of antibiotic use. Although large amounts of fishmeal have been released into the sediment, the role of fishmeal in ARG dissemination remains unclear. In this study, high-throughput ARG profiles in representative fishmeal products and the impact of fishmeal on the sediment resistome were investigated. A total of 132 unique ARGs and 4 mobile genetic elements (MGEs) were detected in five fishmeal products. ARG abundance and diversity in the mariculture microcosm sediment were significantly increased by the addition of fishmeal, and trends in ARG patterns correlated with the resident bacterial community in sediment (P < 0.05). After DNase treatment of fishmeal removed 84.3% of total ARGs, the remaining nutrients in fishmeal increased the relative abundance but not the diversity of ARGs in microcosm sediment. Our study has revealed for the first time that fishmeal itself is a major reservoir for ARGs, and the shift in the bacterial community induced by the nutrients in fishmeal is the main driver shaping the resistome in mariculture microcosm sediment. Our findings caution against the previously unperceived risk of ARG propagation in fishmeal-receiving ecosystems.

https://pubs.acs.org/doi/abs/10.1021/acs.est.7b02875