Bacterial communities and antibiotic resistance genes in seawater adjacent to inhabited and uninhabited xisha coral reef islands: Insights from 16S rRNA and metagenomic sequencing

作者：Yang X, Wu P, Li C, Zheng Q, Shi X, Su H, Wang T, Xiong X, Liu Y, Xiao Y, Xu S, Zou J, Liu Y · 发表于：Marine environmental research · 年份：2026 · DOI：10.1016/j.marenvres.2026.108197 · 研究领域：Coral Reefs、Bacteria、Seawater、Microbiota、Drug Resistance, Microbial、RNA, Ribosomal, 16S、China、Metagenomics、Environmental Monitoring、Metagenome、Genes, Bacterial

The Xisha coral reefs are highly biodiverse ecosystems in the South China Sea, China. Bacterial communities drive energy flow and biogeochemical cycling in coral-reef ecosystems, and serve as indicators of reef health. Yet the composition and dynamics of both bacterial assemblages and ARGs within the Xisha coral reefs remain poorly resolved. This study used 16S rRNA amplicon and metagenomic sequencing to compare bacterial community structure across surface and bottom waters, and surface-water ARGs profiles, in Beijiao Reef (BJ; an uninhabited reef) and Qilianyu Islands (QLY; an inhabited island) of the Xisha Islands. The results revealed bacterial community composition, bacterial co-occurrence network structure, and ARGs profiles differed markedly between the two reef areas. Dominant genera-Prochlorococcus_MIT9313, Salinimonas, Synechococcus_CC9902, Vibrio, and Alteromonas-were significantly more abundant in BJ (p < 0.05), whereas QLY showed higher abundances of Planococcus, Psychrobacter, Jeotgalibacillus, Salinicoccus, and Marinococcus (p < 0.05). The QLY bacterial co-occurrence network exhibited greater complexity (higher clustering coefficients and modularity), whereas the BJ network was simpler but displayed significantly higher closeness-centrality values (p < 0.001). Surface waters of the Xisha Islands were dominated by tetracycline, aminoglycoside, and macrolide resistance genes, whereas sulfonamide and multidrug resistance genes were less abundant. In addition, ARGs ...