摘要

抗生素抗性基因（ARG）在海水养殖沉积物中是全球普遍存在的，并且它们的存在是抗生素使用背景中关注的问题。虽然大量的鱼粉已经释放到沉积物中，但是鱼粉在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吞吐量ARG曲线以及鱼粉对沉积物胶体组成的影响。在五种鱼粉产品中共检测到132种独特的ARGs和4种移动遗传因子（MGEs）。加入鱼粉后，海水养殖微量沉积物ARG丰度和多样性显着增加，ARG模式趋势与沉积物中常驻细菌群落相关（P <0.05）。在DNase处理鱼粉去除总ARGs的84.3％之后，鱼粉中剩余的营养物增加了相对丰度，但并不增加微型沉积物中ARG的多样性。我们的研究首次发现鱼粉本身是ARGs的主要储存器，并且由鱼粉营养素诱导的细菌群落的变化是形成海水养殖微观世界沉积物中的抗体组的主要驱动因素。我们的研究结果提醒注意以前在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