摘要

       抗生素抗性基因 (ARG) 作为一种新出现的污染物，其独特之处在于它们通过环境中的水平基因转移进行传播。在本研究中，从珠江 (PR) 到珠江口 (PRE) 的水和沉积物样品中测量了 1 类整合子基因 (int1) 和各种 ARG（sul1、sul2、sul3、qnrS 和 ermB） ，其中人为影响存在明显的梯度。在所有样品中均检测到 int1、sul1 和 sul2 基因，它们的浓度表现出明显的下降趋势，与人为影响一致。 int1 和 sul 基因都在水和沉积物之间动态迁移。归一化为 16S rRNA 基因的 int1 基因的相对丰度与水和沉积物中抗生素的总浓度显着相关。在样本中 int1 的丰度和每种类型的 sul 基因之间也观察到了良好的相关性。然而，sul1 基因在不同季节与 int1 表现出更强的关系，可能是由于 sul1 存在于 1 类整合子的保守区域。我们的结果强烈支持整合子在 ARGs 在人类影响的水生环境中的传播中发挥重要作用。

       Antibiotic resistance genes (ARGs), as a newly emerging contaminant, are unique because they are disseminated through horizontal gene transfer in the environment. In the present study, a class 1 integron gene (int1) and various ARGs (sul1, sul2, sul3, qnrS, and ermB) were measured in water and sediment samples from the Pearl River (PR) to the Pearl River Estuary (PRE), where there is a distinct gradient in anthropogenic impact. The int1, sul1, and sul2 genes were detected in all samples, and their concentrations exhibited a clear trend of decline consistent with anthropogenic impact. Both the int1 and sul genes had dynamically migrated between water and sediments. The relative abundance of the int1 gene normalized to the 16S rRNA gene correlated significantly with the total concentrations of antibiotics in water and sediments. Good correlations were also observed between the abundance of int1 and each type of sul gene in the samples. However, the sul1 gene showed a much stronger relationship with int1 in different seasons, probably due to the presence of sul1 in the conserved region of class 1 integron. Our results strongly support that integrons play an important role in the dissemination of ARGs in human-impacted aquatic environments.
https://www.sciencedirect.com/science/article/abs/pii/S0304389414004671