厦门市近岸海域水环境抗生素抗性基因污染分布特征

Profiles of Antibiotic Resistance Genes in the Coastal Aquatic Environment of Xiamen City

海岸带及毗连海岛是人类经济社会发展的热点区域,城市化、工业化和农业活动等人类活动对近岸海域水环境生态环境产生了深刻的影响.抗生素抗性基因(ARGs)作为一种新污染物,是当前水生态安全研究和公共关注的热点,但是近岸海域水环境ARGs污染研究比较匮乏.基于厦门市近岸海域地理环境特征,采用高通量定量PCR技术,深入研究了近岸海域水环境中抗生素抗性基因的种类丰度水平和分布格局.并结合16S rDNA基因扩增子测序方法,探究了水体环境微生物群落结构与组成,深入阐释了近岸海域抗生素抗性基因的影响因素和赋存变化机制.结果表明,近岸海域水体环境总共检测出187种抗生素抗性基因,丰度水平高达1.29×10^(10) copies·L^(-1),多重耐药类、氨基糖苷类和β内酰胺类是厦门市近岸海域水体环境最主要的3大类抗生素抗性基因,整体上呈现出丰度较高、种类多样以及普遍共存的特点,近岸海域水环境是抗生素抗性基因分布的重要热区和储存库;Nautella、Candidatus、Tenacibaculum、Rubripirellula和Woeseia等22种微生物是相应16种抗生素抗性基因的潜在携带者,可移动遗传元件(MGEs)和微生物群落结构对近岸海域水体环境抗性基因变化的综合解释量达到了93.9%,说明微生物群落及其可移动遗传元件是近岸海域水体抗生素抗性基因赋存和演化最重要的驱动力.以上研究结果说明,厦门市近岸海域水体环境抗生素抗性基因具有潜在的水生态安全及人类健康风险,能够为近岸海域水体环境微生物及ARGs污染控制提供科学支撑.

The coastal areas and the adjacent islands are the hotspots of human economic and social activities,including urbanization,industrialization,and agricultural practices,which have profound impacts on the ecological environment of the coastal environment.Antibiotic resistance genes(ARGs),as emerging contaminants,have become hot topics in water ecological security and public concern.However,the profiles of antibiotic resistome in the costal water remain largely unknown,impeding resistome risk assessment associated with coastal environments.In this study,the high-throughput quantitative PCR technique was used to investigate the abundance and distribution of ARGs in the coastal environment of Xiamen City.Combined with the 16S rDNA gene amplicon sequencing method,the structure and composition of the microbial community in a water environment were investigated,and the influencing factors and associated mechanism of ARGs in seawater were deeply explained.The results of this study showed that a total of 187 ARGs were detected in the coastal water environment,and the abundance level was up to 1.29×10^(10) copies·L^(−1).Multidrug resistance,aminoglycosides,andβlactamase resistance genes were the three main classes of antibiotic resistance genes in the water environment of the Xiamen coastal zone.On the whole,the profile of ARGs was of high abundance,great diversity,and common co-existence,and the coastal water environment was an important hot area and reservoir for antibiotic resistance genes.Twenty-two microbes,including Nautella,Candidatus,Tenacibaculum,Rubripirellula,and Woeseia,were potential carriers of the corresponding 16 antibiotic resistance genes.The mobile genetic elements(MGEs)and microbial community structure accounted for 93.9%of the variation in environmental resistance genes in water.Therefore,microbial community and its mobile genetic elements were the most important driving forces for the occurrence and evolution of ARGs in coastal waters.Based on the results,it is implied that the environmental antibiotic resistance genes in the waters near Xiamen Island have potential risks to water ecological security and human health and highlight the necessity for comprehensive surveillance of ARGs associated with microbial contamination in the coastal aquatic environment.