Metagenomic analysis reveals microbiome and resistome in the seawater and sediments of Kongsfjorden (Svalbard, High Arctic)

Kongsfjorden in the high Arctic, a typical Arctic fjord, experienced long-time input of nutrients and pollutants from the remote and local resources, providing a platform for characterizing the diversity and distribution of antibiotic resistance genes (ARGs). However, the microbiome and antibiotic resistome in this pristine marine system have not been well documented. The present study aimed to identify the diversity and distribution of bacterial communities and associated ARGs in seawater (12 samples) and sediments (13 samples) of Kongsfjorden via metagenomic analysis. In terms of both bacterial community compositions and ARGs profiles, the seawater was significantly distinct from sediment. Only 29 ARG subtypes were detected in the Arctic seawater and sediments. Furthermore, three geochemical factors (i.e., longitude, depth, and PO43-) greatly influenced the bacterial communities in sediment samples, while longitude, depth, and latitude were crucial geochemical factors influencing the ARGs profiles in sediment samples. Procrustes analysis revealed a significant correlation between bacterial community compositions and ARG profiles in seawater and sediment samples. Network analysis further revealed the co-occurrence of metagenome-assembled genomes (MAGs) with ARG subtypes. Overall, our study provides insights into the microbiome and resistome in a pristine Arctic fjord, thereby providing vital information for environmental management.