摘要
      抗生素耐药性基因（ARGs）成为一种新兴的污染物，并被发现在自然和人为环境中积累。全面了解原始环境中ARG的多样性和丰度对于确定环境ARG的基线水平至关重要。然而，关于原始环境，特别是浅海热液喷口生态系统的ARG剖面，现有信息有限。在此，我们将16S rRNA基因全长扩增子测序和高通量定量PCR（HT-qPCR）相结合，研究了龟山岛浅海热液喷口生态系统中的细菌群落、ARG丰度和多样性。16S rRNA基因扩增子测序结果表明，几个与硫循环相关的细菌属，包括硫微弹菌属、硫还原菌属、硫酸杆菌属、硫单胞菌属和Lebetimonas，在浅海系统的水柱中占主导地位。温度是形成细菌群落的重要因素。HT-qPCR分析结果表明，与其他原始（即西藏湖泊沉积物、海水和沉积物）和人为干扰（即饮用水库、城市池塘和污水处理厂）相比，龟山涛浅海系统的ARG多样性（平均10个ARG亚型）和丰度（平均每个细菌细胞1.0 10−3个拷贝）最低环境。Procrustes分析表明，在浅海系统中，细菌群落的组成和ARGs之间存在一致的模式，而变异划分分析表明，物理化学和细菌群落的共同作用解释了ARGs组成80%以上的变异。这些结果表明，喷口细菌群落和当地环境因素在形成ARG分布中发挥了重要作用。我们的研究首次全面概述了浅海热液喷口生态系统中ARGs的背景水平。
Abstract
Antibiotic resistance genes (ARGs) became an emerging contaminant, and were found to accumulate in natural and man-made environments. A comprehensive understanding of the diversity and abundance of ARGs in pristine environments is critical for defining the baseline levels of environmental ARGs. However, there is limited information available on the ARG profiles of pristine environments, especially for shallow-sea hydrothermal vents ecosystems. Here, we combined 16S rRNA gene full-length amplicon sequencing and high-throughput quantitative PCR (HT-qPCR) to study the bacterial communities, and ARG abundance and diversity in the shallow-sea hydrothermal vent ecosystem of the Kueishantao Islet. The results of the 16S rRNA gene amplicon sequencing showed that several sulfur-cycling related bacterial genera, including Thiomicrorhabdus, Thioreductor, Sulfurovum, Sulfurimonas and Lebetimonas, dominated in the water column of the shallow-sea system. Temperature was the significant factor shaping the bacterial communities. The results of HT-qPCR analysis showed that the Kueishantao shallow-sea system harbored the lowest diversity (average 10 ARG subtypes) and abundance (average 1.0 10−3 copy per bacterial cell) of ARGs compared with other pristine (i.e., Tibet lake sediments, marine water and sediments) and anthropogenic-disturbed (i.e., drinking water reservoirs, urban ponds and wastewater treatment plants) environments. Procrustes analysis demonstrated a concordant pattern between the compositions of bacterial communities and ARGs in the shallow-sea system, while variation partition analysis revealed that the shared effects of physicochemical and bacterial communities explained >80% of the variation in the composition of ARGs. These results suggest that the vent bacterial communities and local environmental factors played an important role in shaping the distribution of the ARG profiles. Our study provides the first comprehensive overview of the background level of ARGs in a shallow-sea hydrothermal vent ecosystem.

https://www.mdpi.com/2071-1050/14/3/1776