摘要

沿海地区是海洋和陆地之间的过渡区，细胞内抗生素抗性基因（iARGs）和细胞外抗生素抗性基因（eARGs）可以在海洋生物之间以及人类和海洋生物之间传播。然而，对海洋环境中的iARG和eARG的综合研究很少受到关注。在此背景下，我们收集了中国渤海湾沿岸地区的水和沉积物样本，并进行了分子和化学分析。定量实时荧光定量PCR（qPCR）结果显示，水样中eARGs的相对丰度高达4.3±1.3×10-1个基因拷贝/ 16S rRNA拷贝，2.6±0.3×10-3个基因拷贝/ 16S rRNA在沉积物样品中复制。此外，eARG的丰度显着高于iARG。此外，来自河口的水和沉积物样品中抗生素抗性基因（ARG，包括iARG和eARG）的平均丰度最高。液相色谱 - 质谱分析结果表明，海水养殖场附近地区的抗生素浓度高于其他地区。细胞内DNA中的1类整合子基因（int1）和sul1在水样中显着相关。此外，在沉积物样品中也发现细胞外DNA中int1和sul2之间的显着相关性。磺胺甲嘧啶和四环素的组合以及磺胺二甲嘧啶和溶解氧的组合都可以解释ARG的丰度，这意味着多种应激对ARG的综合影响。

Coastal areas are the transition zones between ocean and land where intracellular antibiotic resistance genes (iARGs) and extracellular antibiotic resistance genes (eARGs) could spread among marine organisms, and between humans and marine organisms. However, little attention has been paid to the combined research on iARGs and eARGs in marine environment. In this context, we collected water and sediment samples from the coastal areas of the Bohai Bay in China and performed molecular and chemical analyses. The results of quantitative real-time PCR (qPCR) showed that the relative abundance of eARGs was up to 4.3 ± 1.3 × 10-1 gene copies/16S rRNA copies in the water samples and 2.6 ± 0.3 × 10-3 gene copies/16S rRNA copies in the sediment samples. Also, the abundance of eARGs was significantly higher than that of iARGs. Furthermore, the average abundances of antibiotic resistance genes (ARGs, include iARGs and eARGs) were the highest in both the water and sediment samples from the estuaries. The results of liquid chromatography-mass spectrometry showed that the concentrations of antibiotics in estuaries and areas near the mariculture site were higher than that in the other sites. The class 1 integron gene (int1) and sul1 in the intracellular DNA were significantly correlated in the water samples. Moreover, significant correlation between int1 and sul2 in the extracellular DNA was also found in the sediment samples. The combination of sulfamerazine and tetracycline as well as the combination of sulfamethazine and dissolved oxygen can both explain the abundance of ARGs, implying the combined effects of multiple stresses on ARGs.

https://europepmc.org/abstract/med/29414333