Efficient Degradation of Intracellular Antibiotic Resistance Genes by Photosensitized Erythrosine-Produced O-1(2)

Intracellularantibiotic resistance genes (iARGs) constitute theimportant part of wastewater ARGs and need to be efficiently removed.However, due to the dual protection of intracellular DNA by bacterialmembranes and the cytoplasm, present disinfection technologies arelargely inefficient in iARG degradation. Herein, we for the firsttime found that erythrosine (ERY, an edible dye) could efficientlydegrade iARGs by producing abundant O-1(2) undervisible light. Seven log antibiotic-resistant bacteria were inactivatedwithin only 1.5 min, and 6 log iARGs were completely degraded within40 min by photosensitized ERY (5.0 mg/L). A linear relationship wasestablished between ARG degradation rate constants and O-1(2) concentrations in the ERY photosensitizing system.Surprisingly, a 3.2-fold faster degradation of iARGs than extracellularARGs was observed, which was attributed to the unique indirect oxidationof iARGs induced by O-1(2). Furthermore, ERY photosensitizingwas effective for iARG degradation in real wastewater and other photosensitizers(including Rose Bengal and Phloxine B) of high O-1(2) yields could also achieve efficient iARG degradation. The findingsincrease our knowledge of the iARG degradation preference by O-1(2) and provide a new strategy of developing technologieswith high O-1(2) yield, like ERY photosensitizing,for efficient iARG removal. TheERY photosensitizing system can achieve efficient iARGdegradation through high O-1(2) production, whichis a cost-effective disinfection technology for simultaneous removalof ARB and iARGs.

Automated summary

In this study, it was found that erythrosine (ERY), an edible dye, can efficiently degrade intracellular antibiotic resistance genes (iARGs) by generating abundant O-1(2) under visible light. The degradation of 6 log iARGs was achieved within 40 minutes. The unique indirect oxidation of iARGs induced by O-1(2) resulted in a 3.2-fold faster degradation of intracellular ARGs compared to extracellular ARGs. Additionally, other photosensitizers with high O-1(2) yields, such as Rose Bengal and Phloxine B, also demonstrated efficient iARG degradation.