海州湾近岸海域的微生物群落结构和抗生素抗性基因时空变化

【背景】近岸海域抗生素抗性基因(antibiotic resistance genes, ARGs)的污染和累积将直接影响海产品质量和安全，海州湾作为江苏省的四大渔场之一，是江苏渔业发展的主要载体，有多条大小河流注入，沿岸为重要农业区，对公众健康产生重大影响。【目的】对海州湾夏秋季的水样及沉积物展开微生物及ARGs检测。【方法】基于宏基因组测序技术开展海州湾夏秋两季近岸6个站点中水体和沉积物中ARGs种类和相对丰度以及微生物群落的组成研究。【结果】变形菌门(Proteobacteria)和放线菌门(Actinobacteria)是夏秋季度两种介质中最优势的门类，水样中优势的科级细菌为红细菌科(Rhodobacteraceae)，沉积物样品中为脱硫杆菌科(Desulfobacteraceae)；夏季水样中的ARGs相对丰度要明显高于秋季，但沉积物中不同季节的ARGs相对丰度未表现出明显的变化趋势；在水样中主要门级微生物群落的抗性机制主要是抗生素靶位替换和抗生素靶位保护，沉积物样品则以抗生素灭活机制为主，而主要科级微生物群落的抗性机制更加多样；冗余分析(redundancyanalysis...

Spatial and temporal changes of microbial community structure and antibiotic resistance genes in the coastal waters of Haizhou Bay

Background] The pollution and accumulation of antibiotic resistance genes (ARGs) in coastal waters directly affect the quality and safety of seafood. As one of the four major fishing grounds, Haizhou Bay is the main carrier of fishery development in Jiangsu province, with multiple rivers injected. The coast is an important agricultural area with a significant impact on public health. Objective] To study the microorganisms and ARGs in the water and sediment samples collected from six points of Haizhou Bay in summer and autumn. Methods] Metagenomic sequencing was employed to determine the composition and relative abundance of microorganisms and ARGs. Results] Proteobacteria and Actinobacteria were the most dominant phyla in the two media in summer and autumn. The dominant families in water and sediment samples were Rhodobacteraceae and Desulfobacteraceae, respectively. The relative abundance of ARGs in water samples in summer was significantly higher than that in autumn, while the relative abundance of ARGs in sediments did not show a significant trend in different seasons. The resistance mechanisms of the main phyla in water samples were mainly antibiotic target replacement and antibiotic target protection, while that in the sediment samples was mainly antibiotic inactivation. The main families had more diverse resistance mechanisms. Redundancy analysis (RDA) and canonical correspondence analysis (CCA) showed that environmental factors such as nitrate and salinity were significantly correlated with the changes of ARGs.Conclusion] The microbial community and ARGs in the coastal area of Haizhou Bay varied in different media in summer and autumn, and the main microbial communities in different media adopt different resistance mechanisms. The relative abundance and distribution of ARGs were regulated by environmental factors such as salinity and nitrate. The findings provide a theoretical basis for public safety monitoring and environment protection in Haizhou Bay.