Prion and Prionoid Research Unit, Division Proteomics and Spectroscopy, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Berlin, Germany; Division Hospital Hygiene, Infection Prevention and Control, Department of Infectious Diseases, Robert Koch Institute, Berlin, Germany.
Prion and Prionoid Research Unit, Division Proteomics and Spectroscopy, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Berlin, Germany.
J Hosp Infect. 2023 Feb;132:125-132. doi: 10.1016/j.jhin.2022.08.014. Epub 2022 Oct 7.
Prions are renowned for their distinct resistance to chemical or physical inactivation, including steam sterilization. Impaired efficacy of inactivation poses a risk to patients for iatrogenic transmission of Creutzfeldt-Jakob disease (CJD) via contaminated surgical instruments.
Most established prion inactivation methods were validated against scrapie agents, although those were found to be generally less thermostable than human prions. Thus, knowledge gaps regarding steam-sterilization kinetics of CJD prions should be filled and current guidelines reviewed accordingly.
Prion inactivation through widely recommended steam sterilization at 134°C was assessed for several holding times by analysing the residual prion seeding activity using protein misfolding cyclic amplification (PMCA).
Scrapie 263K was found to be the least thermoresistant prion strain showing no seeding activity after 1.5 min at 134°C, while variant CJD was the most stable one demonstrating some seeding activity even after 18 min of steam sterilization. Sporadic CJD subtype VV2 exhibited residual seeding activity after 3 min, but no detectable activity after 5 min at 134°C.
Validated steam sterilization for 5 min at 134°C as previously recommended for the routine reprocessing of surgical instruments in contact with high-risk tissues is able to substantially reduce the seeding activity of CJD agents, provided that no fixating chemical disinfection has been performed prior to sterilization and that thorough cleaning has reduced the protein load on the surface to less than 100 μg per instrument.
朊病毒以其对化学或物理失活的独特抗性而闻名，包括蒸汽灭菌。失活效果受损会使患者面临通过受污染的手术器械医源性传播克雅氏病（CJD）的风险。
大多数已建立的朊病毒失活方法都是针对瘙痒剂进行验证的，尽管这些方法通常比人类朊病毒的热稳定性差。因此，应该填补有关 CJD 朊病毒蒸汽灭菌动力学的知识空白，并相应地审查当前指南。
通过广泛推荐的 134°C 蒸汽灭菌，使用蛋白质错误折叠循环扩增（PMCA）分析残留朊病毒接种活性，评估了几种保持时间的朊病毒失活情况。
瘙痒 263K 是最耐热性较差的朊病毒株，在 134°C 下 1.5 分钟后没有接种活性，而变异 CJD 是最稳定的，即使在 18 分钟的蒸汽灭菌后仍具有一些接种活性。散发性 CJD 亚型 VV2 在 3 分钟后仍具有残留的接种活性，但在 134°C 下 5 分钟后则没有可检测到的活性。
如先前推荐的那样，对于接触高危组织的手术器械的常规再处理，验证的 5 分钟 134°C 蒸汽灭菌能够显著降低 CJD 剂的接种活性，前提是在灭菌前没有进行固定化学消毒，并且彻底清洁将表面的蛋白质负载减少到每个器械少于 100μg。
