摘要
      河口环境中的抗生素抗性基因（ARG）污染引起了人们的高度关注，目前尚不清楚盐度、总有机碳、总氮、总磷和抗生素等物理和化学参数是否会影响ARG的分布。在此，我们使用基于高通量测序的宏基因组学分析，破译了中国九龙江口（JRE）和岷江口（MRE）沉积物中的ARG图谱和微生物群落组成。此外，我们还探讨了盐度对细菌群落和ARG谱的影响。结果表明，变形菌门、绿弯菌门和酸杆菌门是这两个河口的优势门。在所有沉积物样本中，每拷贝16S rRNA基因的ARG丰度为1.05×10−1至2.93×。多药耐药基因是两个河口的主要ARG类型，每个16S rRNA基因拷贝的ARG总丰度为2.39×10−2–1.07×10−1拷贝，其次是对杆菌肽和大环内酯林可酰胺链脲菌素产生耐药性的基因。盐度是细菌群落的一个重要影响因素，但对ARG谱没有影响。相反，随机过程对ARGs的分布产生了主要影响。河口沉积物、海洋沉积物和人为污染环境样品之间ARG剖面的比较表明，河口沉积物样品和城市污水处理厂样品之间的ARG剖面具有显著的相似性。这些结果表明，人为污染的复杂排放可能导致ARGs的随机生态模式。
Abstract
Antibiotic resistance gene (ARG) pollution in estuarine environment has drawn great attention, and it is not clear if the physical and chemical parameters such as salinity, total organic carbon, total nitrogen, total phosphorus and antibiotics affects the distribution of ARGs. Herein, we deciphered the ARG profiles and microbial community compositions in sediments from Jiulong River Estuary (JRE) and Min River Estuary (MRE) of China using high-throughput sequencing-based metagenomics analysis. Furthermore, we explored the influence of salinity on bacterial community and ARG profiles. The results showed that Proteobacteria, Chloroflexi, and Acidobacteria were the dominant phyla in these two estuaries. The abundance of ARGs ranged from 1.05 × 10−1 to 2.93 × 10−1 copy of ARG per copy of 16S rRNA gene in all the sediment samples and the profiles of ARGs presented similar patterns in two estuaries. Multidrug resistance genes were the dominant ARG types in both estuaries, with an overall abundance of 2.39 × 10−2–1.07 × 10−1 copy of ARG per copy of 16S rRNA gene, followed by genes conferring resistance to bacitracin and macrolide-lincosamide-streptogramin. Salinity was an important influencing factor on the bacterial community but not on the ARG profiles. Instead, stochastic processes exerted the main influence on the distribution of ARGs. The comparison of ARG profiles among estuary sediments, marine sediments, and samples from anthropogenic pollution environments revealed remarkable similarity of ARG profiles between samples from estuary sediments and those from municipal wastewater treatment plants. These results suggested that the complex emission of anthropogenic pollution could cause the stochastic ecological pattern of ARGs.

https://www.sciencedirect.com/science/article/abs/pii/S0048969721064688