UVC Sterilizing Filter Eliminates and Inactivates Antibiotic-Resistant Bacteria and Genes in Post-rainfall Stream Water

UVC Sterilizing Filter Eliminates and Inactivates Antibiotic-Resistant Bacteria and Genes in Post-rainfall Stream Water Antibiotic resistance (AR), responsible for ~ 700,000 annual global deaths and projected to claim 10 million lives by 2050, is exacerbated by the environmental proliferation of antibiotic-resistant bacteria (ARBs) and antibiotic resistance genes (ARGs). Household activated carbon (AC) filters, while widely used for tap water purification, unfortunately foster microbial colonization and horizontal gene transfer (HGT) of ARGs. Here, we present a novel ultraviolet-C sterilizing filter (UVC-SF) that integrates an activated carbon block (ACB) with an embedded UVC Light Emitting Diode (UVC-LED) rod (265 nm emission) to address these challenges. Operating at 0.5 L/min (inside-to-outside flow), the UVC-SF eliminated > 99.86% of viable ARBs represented as total coliforms (TCF) and streptomycin-, ampicillin-, and levofloxacin-resistant TCF (AR-TCF) at a UV fluence of 64 mJ/cm². Critically, the system inactivated > 96.89% of functional ARGs quantified via transformed Escherichia coli DH5α through synergistic adsorption and UVC-induced DNA damage. In contrast, standalone ACB filtration removed < 36% of viable ARBs and < 37% of functional ARGs. A self-cleaning protocol combining 50°C pure water backwashing and UVC irradiation (64 mJ/cm²) eliminated > 99.99% (3.43-5.09-log reduction) of accumulated ARBs/ARGs on the inner surface of central flow channel of the ACB. This study provides an integrated approach for detection of horizontally transferable and functional ARGs and demonstrates the UVC-SF achieves real-time ARBs/ARGs removal with self-cleaning regeneration of the ACB filter—a critical advancement over household water purifiers.