摘要

       淡水中的微生物群落引起了人们对生态系统和人类健康的担忧。城市河流由于不合理的利用和长期的废水排放，已经发现了许多生态环境问题。在这项研究中，我们探索了中国西安巴河的 7 个水样和 7 个沉积物样品中的细菌群落组成、14 种抗生素和 21 种抗生素抗性基因 (ARG) 的丰度以及水环境特征。结果表明，所有样品中变形菌门和拟杆菌门是优势门，沉积物样品的细菌多样性和丰富度高于水中。与来自其他样本的其余站点的细菌群落相比，站点 5 和 6 的细菌群落以不同的模式聚集。它可能受到营养素、重金属和抗生素的影响。水样中抗生素浓度范围为 1.26 至 1.61 × 103 ng L-1，沉积物样品中抗生素浓度范围为 1.55 至 4.05 × 102 μg kg-1。磺胺美嗪（SM1）和红霉素（ERY）是水样中的主要抗生素，而沉积物中土霉素（OTC）和头孢唑啉（CFZ）的含量较高。 典型对应分析表明甲氧苄啶（TMP）在W6与不动杆菌呈显着相关，SM1和OTC在W5与Arcobacter呈正相关。 在所有样本中，tetC、blaTEM、ermF 和 sul1 具有更高的污染丰度，范围从 10-4 到 100 拷贝/16S rRNA 基因拷贝。 在 ARGs 和匹配的抗生素之间观察到显着的相关性，表明抗生素可以对这条河流中的 ARGs 产生选择压力。 总而言之，这些发现可能为中国城市河流中细菌群落特征、抗生素丰度和 ARGs 的有限信息提供一些新数据。 .

       The microbial communities in freshwater have caused concerns about ecosystems and human health. Due to unreasonable utilization of urban rivers and long-term waste water discharge, many ecological and environmental problems have been discovered. In this study, we explored the bacterial community composition, the abundance of 14 antibiotics and 21 antibiotic resistance genes (ARG), and the characteristics of the water environment in 7 water samples and 7 sediment samples from the Bahe River in Xi’an, China . The results showed that the Proteobacteria and Bacteroides were the dominant phyla in all samples, and the bacterial diversity and abundance of sediment samples were higher than that of water. Compared with the bacterial communities at the remaining sites from other samples, the bacterial communities at sites 5 and 6 aggregated in a different pattern. It may be affected by nutrients, heavy metals and antibiotics. The concentration of antibiotics in water samples ranged from 1.26 to 1.61 × 103 ng L-1, and the concentration of antibiotics in sediment samples ranged from 1.55 to 4.05 × 102 μg kg-1. Sulfamethazine (SM1) and erythromycin (ERY) are the main antibiotics in water samples, while the sediments contain higher levels of oxytetracycline (OTC) and cefazolin (CFZ). Typical correspondence analysis showed that trimethoprim (TMP) was significantly correlated with Acinetobacter at W6, and SM1 and OTC were positively correlated with Arcobacter at W5. In all samples, tetC, blaTEM, ermF and sul1 have higher contamination abundance, ranging from 10-4 to 100 copies/16S rRNA gene copies. A significant correlation was observed between ARGs and matched antibiotics, indicating that antibiotics can exert selective pressure on ARGs in this river. All in all, these findings may provide some new data for the limited information on bacterial community characteristics, antibiotic abundance, and ARGs in urban rivers in China. .

https://www.frontiersin.org/articles/10.3389/fmicb.2018.03191/full