Double-edged sword of FeS oxidation in estuarine and coastal sediments: accelerating elemental cycling yet enhancing antibiotic resistance enrichment.

FeS oxidation in estuarine and coastal sediments significantly increases ARG enrichment and dissemination, with a notable rise in Proteobacteria associated with metabolic pathways.

• Why it matters: Understanding how biogeochemical processes influence antibiotic resistance gene spread is crucial for environmental risk assessment and management of coastal ecosystems.
• What they did: Microcosm experiments and field investigations examined the effects of FeS amendment on microbial communities, elemental cycling, and ARG abundance, revealing aerobic-dependent ARG enrichment linked to Proteobacteria.
• The result: FeS oxidation enhances ARG enrichment through metabolic coupling of sulfur, nitrogen, and carbon cycles, but may also suppress ARG proliferation depending on oxygen conditions, emphasizing the role of redox dynamics in ARG dissemination.