The high Arctic resistome: stress-response genes, virulence determinants, and microbial populations in human-impacted environments of Spitsbergen.

The high Arctic, particularly Spitsbergen, faces the combined challenges of climate change and other anthropogenic pressures - including waste and contaminant release from human activity - that influence microbial populations and the spread of antimicrobial resistance (AMR). This study presents a snapshot analysis of metagenomes from various environments across Spitsbergen, including untreated and treated wastewater outflows, fjords, and glacial ice cores, to explore the abundance of stress-response genes, including antibiotic resistance genes (ARGs), biocide resistance genes (BRGs), metal resistance genes (MRGs), and virulence genes (VGs), alongside the compositions of the associated bacterial populations. We reveal varying levels of stress-response genes and VGs in environments exposed to differing levels of human influence. ARGs and MRGs dominate in raw sewage, while VGs are more prevalent in fjord waters receiving both raw sewage and effluent, indicating that specific environmental conditions favor different resistance and virulence traits. We detect high abundance of ARGs and VGs downstream of both untreated and treated wastewater. Our analyses indicate the presence of bacterial populations with resistance and virulence traits - including Enterobacteriaceae, Enterococcaceae, Bacillaceae, and Staphylococcaceae - in downstream ecosystems. While we do not directly assess effects on human health or ecosystem function, these observations point to potential ecological impacts in Arctic environments and highlight the importance of continued monitoring to understand and manage the possible effects of human activities and climate change.