摘要
      沿海滩涂是陆地和海洋环境的交汇区，被认为是人类活动（如渔业和水产养殖）污染物的储存地。具体而言，抗生素和抗生素抗性基因（ARGs）在沿海水产养殖环境中的流行对河口生态系统构成了严重威胁。然而，在滩涂区，水产养殖对ARGs和群落聚集的发生和丰度的贡献尚未得到充分探讨。因此，我们使用宏基因组组装方法研究了中国江苏东台和射阳滩涂养殖区的ARGs图谱、携带ARG的宿主细菌及其相关微生物群落。沉积物样品中的抗生素浓度在nd-35.50 ng/g dw之间，东台滩涂的抗生素污染比射阳滩涂更严重。宏基因组组装表明，在所有样本中，共有247种与ARG 33型相关的ARG亚型被表征，它们在东台地区的丰度超过了射阳地区。同时，滩涂养殖中的21种细菌被鉴定为携带ARG的病原体，包括大肠杆菌、流感弧菌和金黄色葡萄球菌。使用中性和零建模分析来确定群落生态过程，结果表明细菌和ARG群落通常分别由随机和确定性过程主导。上述结果表明，水产养殖污染是形成滩涂ARG剖面的原因之一。在滩涂水产养殖中观察到的影响ARG群落的确定性过程也为通过减少水产养殖抗生素的使用来控制环境抗生素耐药性的风险提供了有效的基础。
Abstract
Coastal tidal flats are intersection zones between terrestrial and marine environments and are considered repositories of pollutants from anthropogenic activities (e.g., fishery and aquaculture). Specifically, the prevalence of antibiotics and antibiotic resistance genes (ARGs) in coastal aquaculture environments pose critical threats to estuarine ecosystems. However, the contribution of aquaculture to the occurrence and abundance of ARGs and community assemblies has not been fully explored in tidal flat zones. Thus, we investigated ARGs profiles, ARG-carrying host bacteria, and their associate microbial community in the Dongtai and Sheyang tidal flat aquaculture regions of Jiangsu, China using metagenomic assembly methods. The antibiotic concentrations in the sediment samples ranged from nd to 35.50 ng/g dw, and the antibiotic pollution in the Dongtai tidal flat was more severe than in the Sheyang tidal flats. Metagenomic assembly indicated that a total of 247 ARG subtypes associated with ARG 33 types were characterized across all samples and their abundance in the Dongtai region exceeded that in the Sheyang region. Meanwhile, 21 bacteria in the tidal flat aquaculture were identified as ARG-carrying pathogens, including Escherichia coli, Vibrio fluvialis, and Staphylococcus aureus. Using neutral and null modeling analysis to determine the community ecological processes, the results revealed bacterial and ARG communities were generally dominated by stochastic and deterministic processes, respectively. The above results suggested that aquaculture pollution was contributed to shape ARG profiles in tidal flats. The observed deterministic processes affecting the ARG community in tidal flat aquaculture also provides an effective foundation to control the risks of environmental antibiotic resistance through reducing aquaculture antibiotic usage.

https://www.sciencedirect.com/science/article/abs/pii/S0048969722022999