Degradation and inactivation of Shiga toxins by nitrogen gas plasma

Abstract

Shiga toxin (Stx)-producing Escherichia coli (STEC) leads to food poisoning by causing hemorrhagic colitis and hemolytic uremic syndrome. Some STEC produce Shiga toxin 1 (Stx1) and/or Shiga toxin 2 (Stx2), a relatively stable protein toxin, necessitating the development of an efficient inactivation method. Here we applied a nitrogen gas plasma apparatus to the inactivation of Stx. Samples of Stx1 and Stx2 were treated with a nitrogen gas plasma generated by a plasma device using a short high-voltage pulse applied by a static induction thyristor power supply at 1.5 kpps (kilo pulse per second). The recovered Stx samples were then analyzed for immunological and biological activities. Immunochromatography demonstrated that Stx1 and Stx2 were degraded by the gas plasma. Quantification by enzyme-linked immunosorbent assay (ELISA) showed that both toxins were efficiently degraded to less than 1/10th of their original concentration within 5 min of treatment. Western blotting further showed the gas plasma treatment degraded the A subunit, which mediates the toxicity of Stx. Moreover, an assay using HEp-2 cells as an index of cytotoxicity showed that gas plasma treatment reduced the toxic activity of Stx. Therefore, nitrogen gas plasma might be an efficient method for the inactivation of Stx.

Disinfection and Sterilization Using Plasma Technology: Fundamentals and Future Perspectives for Biological Applications

“…Differences where ** p < 0.01 versus control (0 min) were considered significant. ( a ) and ( b ) are cited from Sakudo et al [57] with permission from Elsevier, while ( c ) and ( d ) are cited from Sakudo et al [74] under the terms of the Creative Commons Attribution 4.0 International license.…”

Degradation of Toxins Derived from Foodborne Pathogens by Atmospheric-Pressure Dielectric-Barrier Discharge

“…For example, a review article written by Kutasi et al [ 44 ] highlighted the challenges and approaches towards inactivating aflatoxins using UV radiation and pulsed light treatment, ammoniation, ozonation, and gas plasma. Sakudo et al demonstrated the effectiveness of nitrogen gas plasma against aflatoxin B 1 [ 25 ] and Shiga toxins [ 26 ]. Our findings build upon these studies, showcasing the broader applicability and effectiveness of APDBD plasma against a range of foodborne toxins.…”

“…Based on these considerations, we have developed an advanced technique designed to efficiently degrade foodborne toxins whilst preserving the intrinsic characteristics of the food during the decontamination phase. Our previous studies revealed that nitrogen gas plasma treatment can degrade aflatoxin B 1 [ 25 ] and Shiga toxins [ 26 ]. In addition, a broad range of degradation activity against various toxins by plasma has been reported by other research groups [ 27 , 28 ].…”

Cold atmospheric pressure plasmas applications in dentistry

“…Plasma is a novel advanced disinfection/sterilization system that can simultaneously inactivate pathogens, viruses, and their associated toxins. [22,92,97,98] In the late 1960s, plasma was beginning applied to decontaminate surfaces, and in some aspects demonstrated to be more effective than conventional sterilization. [99] What's more, the treatment of plasma exerts relatively little impact on the structural integrity of sterilized samples.…”