摘要

       沉积物中的硫酸盐还原原核生物 (SRPs) 和抗生素抗性基因 (ARGs) 可能是评估人类活动对环境影响的生物标志物，尽管控制它们分布的因素尚不清楚。本研究采用宏基因组学方法调查了从香港 12 个不同沿海地点收集的海洋沉积物中 SRP 和 ARG 的分布，这些沉积物表现出不同的污染水平，并根据沉积物参数分为两组。我们的结果表明，在污染较严重的沉积物中，主要 SRP 属与总原核生物的相对丰度始终较低（20 个属中的 13 个 P 值 < 0.05），表明 SRP 的相对丰度是评估人类的负相关生物标志物。影响。此外，观察到 SRP 的单模型分布模式以及污染梯度。虽然总 ARGs 在污染地点的沉积物中富集，但单一主要 ARG 类型的分布既不能用单独的沉积物参数也不能用相应的抗生素浓度来解释。它支持这样一种假设，即沉积物中 ARG 的持久性可能不需要选择抗生素。总之，我们的研究为海洋沿海沉积物中 SRP 的生态位分化和 ARG 的行为提供了重要提示。

       Sulfate-reducing prokaryotes (SRPs) and antibiotic resistance genes (ARGs) in sediments could be biomarkers for evaluating the environmental impacts of human activities, although factors governing their distribution are not clear yet. By using metagenomic approach, this study investigated the distributions of SRPs and ARGs in marine sediments collected from 12 different coastal locations of Hong Kong, which exhibited different pollution levels and were classified into two groups based on sediment parameters. Our results showed that relative abundances of major SRP genera to total prokaryotes were consistently lower in the more seriously polluted sediments (P-value < 0.05 in 13 of 20 genera), indicating that the relative abundance of SRPs is a negatively correlated biomarker for evaluating human impacts. Moreover, a unimodel distribution pattern for SRPs along with the pollution gradient was observed. Although total ARGs were enriched in sediments from the polluted sites, distribution of single major ARG types could be explained neither by individual sediment parameters nor by corresponding concentration of antibiotics. It supports the hypothesis that the persistence of ARGs in sediments may not need the selection of antibiotics. In summary, our study provided important hints of the niche differentiation of SRPs and behavior of ARGs in marine coastal sediment.

https://academic.oup.com/femsec/article/92/9/fiw128/2197721?login=true