Recent Advances in Prion Inactivation by Plasma Sterilizer

Abstract

Prions, which cause transmissible spongiform encephalopathies (TSEs), are a notorious group of infectious agents with possibly the highest resistance to complete inactivation. Although various gas plasma instruments have been developed, studies on prion inactivation using gas plasma instruments are limited. Among them, the hydrogen peroxide gas plasma instrument, STERRAD® (Advanced Sterilization Products; ASP, Johnson & Johnson, Irvine, CA, USA), is recommended for prion inactivation of heat-sensitive medical devices. However, STERRAD® is not a plasma sterilizer but a hydrogen peroxide gas sterilizer. In STERRAD®, plasma generated by radio frequency (RF) discharge removes excess hydrogen peroxide gas and does not contribute to sterilization. This is also supported by evidence that the instrument was not affected by the presence or absence of RF gas plasma. However, recent studies have shown that other gas plasma instruments derived from air, nitrogen, oxygen, Ar, and a mixture of gases using corona, dielectric barrier, microwave, and pulse discharges can inactivate scrapie prions. As inactivation studies on prions other than scrapie are limited, further accumulation of evidence on the effectiveness of gas plasma using human-derived prion samples is warranted for practical purposes.

Medical Device-Associated Healthcare Infections: Sterilization and the Potential of Novel Biological Approaches to Ensure Patient Safety

“…Prions are more resistant to sterilization than bacterial spores. Therefore, the SAL sterility testing does not guarantee the removal of prions from treated devices [ 62 ]. The findings of Sakudo et al (2022) show that a vaporized mix of hydrogen peroxide and peracetic acid (VHPPA) inactivates prions as determined in mice infectivity assays [ 62 ].…”

“…Therefore, the SAL sterility testing does not guarantee the removal of prions from treated devices [ 62 ]. The findings of Sakudo et al (2022) show that a vaporized mix of hydrogen peroxide and peracetic acid (VHPPA) inactivates prions as determined in mice infectivity assays [ 62 ]. Studies have demonstrated the increased efficacy of this combination of oxidizing agents as bactericidal and sporicidal solutions [ 63 ].…”

New Advances in Viral and Microorganism Disinfectants

“…Therefore, environmentally friendly and non-harmful disinfectants for viruses and microorganisms are still under development. Numerous types of virucidal measures, such as cold gas plasma [4], chemical disinfectants [5], 222 nm UV [6], and photocatalysis [6], have been actively studied and are reported in this collection.…”

Disinfection, Sterilization, and Decontamination of Pathogens in Medicine

“…There are five generally recognized categories in the hierarchy of resistance as follows: (i) extremely resistant (prions), (ii) significantly resistant (bacterial spores, protozoan oocysts, and helminth eggs), (iii) resistant (mycobacteria, protozoan cysts, small nonenveloped viruses, and fungal spores), (iv) susceptible (vegetative bacteria, protozoa, helminths, fungi, algae, and large non-enveloped viruses), and (v) highly susceptible (enveloped viruses) [16][17][18]. Therefore, an in depth understanding of the susceptibility of microorganisms to various inactivation procedures, such as disinfection or sterilization, is necessary.…”