Highly efficient sterilization of biogenic FeS2 nanoparticles: Mechanism and inhibition of antibiotic resistance

As antibiotic-resistant bacteria rapidly render antibiotics ineffective, the development of antibacterial nanomaterials that can replace antibiotics is extremely urgent. Here, novel biogenic FeS 2 (bio-FeS 2 ) nanomaterials with broad-spectrum antibacterial activity were synthesized using biogenic FeS as a precursor, which can delay the onset of bacterial resistance. Both S. aureus and E. coli were completely inactivated by bio-FeS 2 under nutritional conditions. Mechanism studies revealed that bio-FeS 2 exhibited superior antibacterial performance than other iron sulfides attributed to the stronger release of iron and sulfur ions and crystal structure. The antibacterial potency of bio-FeS 2 active components follows the order as below: Fe 2+ >S 2 2- >S 2 2- disproportionation to generate S 2- >washed bio-FeS 2 precipitate. These components synergistically killed bacteria by membrane rupture, glutathione consumption, and lipid peroxidation accumulation. Six strains of antibiotic-resistant E. coli were found in the real municipal wastewater. Bio-FeS 2 kept the initial antibacterial activity against the resistant E. coli after ten passages, demonstrating the ability to impede bacterial resistance, whereas tetracycline induced bacterial resistance within four passages. Furthermore, bio-FeS 2 showed biocompatibility with mammalian cells and aquatic plants. This study proposes an efficient antibacterial agent and offers a promising strategy for the treatment of resistant bacteria.