摘要
      农业地区的河流是畜禽养殖场径流、化肥径流和农村生活污水的重要汇点，可能会带来抗生素抗性基因（ARGs）污染。然而，在受农业影响的河流中，ARGs的多样性和分布并没有得到很好的记录。本文测定了嘉陵江某农业区及其五个农村支流地表水中ARGs的多样性及其与生化因子的关系。使用高通量定量PCR检测到218种编码对八种主要抗生素类耐药性的独特ARGs。支流的ARG丰度明显高于主流。与主流相比，氨基糖苷类、β内酰胺酶、MLSB和多药耐药基因在分支中显著富集。与主流相比，分支中的ARGs剖面表现出明显更高的空间变异性。观察到ARGs谱与细菌群落结构之间的显著相关性，网络分析进一步表明ARGs与其潜在宿主（如Ottowia和Novosphingobium）有关。冗余判别分析表明，Cu含量对河流中ARGs的增加有显著贡献。微生物多样性指数与ARGs的丰度呈负相关。这些结果为受农业影响的河流和支流中ARGs的富集提供了证据，这是由于化学和微生物变量的共同影响。
Abstract
Rivers in agricultural regions serve as an important sink for livestock and poultry farm runoff, fertilizer runoff, and country living sewage, which could bring antibiotic resistance genes (ARGs) contaminations. However, the diversity and distribution of ARGs has not been well documented in the agricultural influenced river. Here, the diversity of ARGs, and their relationship with biochemical factors were determined in the surface water in an agricultural region of the Jialing River and its five rural branches. The 218 unique ARGs encoding resistance to eight major antibiotic classes have been detected using high-throughput quantitative PCR. The branches of the river had a remarkably higher abundance of ARGs than the mainstream. The aminoglycoside, beta_Lactamase, MLSB, and Multidrug resistance genes were significantly enriched in the branches compared to the mainstream. Compared with the mainstream, the ARGs profiles in the branches showed obvious higher spatial variability. Significant correlation between ARGs profiles and bacterial community structures were observed, and network analysis further showed that the ARGs were associated with their potential hosts, such as Ottowia and Novosphingobium. Redundancy discrimination analysis revealed that Cu content has a significant contribution to the increase of ARGs in the river. The microbial diversity index was negatively correlated with the abundance of the ARGs. These results provide evidence for the enrichment of ARGs in the agricultural influenced river and branches due to the joint influence of chemical and microbial variables.

https://www.sciencedirect.com/science/article/abs/pii/S0048969722018320