Efficient Degradation of Intracellular Antibiotic Resistance Genes by Photosensitized Erythrosine-Produced ¹O₂

Abstract

Intracellular antibiotic resistance genes (iARGs) constitute the important part of wastewater ARGs and need to be efficiently removed. However, due to the dual protection of intracellular DNA by bacterial membranes and the cytoplasm, present disinfection technologies are largely inefficient in iARG degradation. Herein, we for the first time found that erythrosine (ERY, an edible dye) could efficiently degrade iARGs by producing abundant 1 O 2 under visible light. Seven log antibiotic-resistant bacteria were inactivated within only 1.5 min, and 6 log iARGs were completely degraded within 40 min by photosensitized ERY (5.0 mg/L). A linear relationship was established between ARG degradation rate constants and 1 O 2 concentrations in the ERY photosensitizing system. Surprisingly, a 3.2-fold faster degradation of iARGs than extracellular ARGs was observed, which was attributed to the unique indirect oxidation of iARGs induced by 1 O 2 . Furthermore, ERY photosensitizing was effective for iARG degradation in real wastewater and other photosensitizers (including Rose Bengal and Phloxine B) of high 1 O 2 yields could also achieve efficient iARG degradation. The findings increase our knowledge of the iARG degradation preference by 1 O 2 and provide a new strategy of developing technologies with high 1 O 2 yield, like ERY photosensitizing, for efficient iARG removal.