Environmental Healthcare Unit, School of Biological Sciences, University of Southampton, Southampton, UK.
Center for Bioelectrics, Old Dominion University, Norfolk, VA, USA.
J Hosp Infect. 2023 Jun;136:100-109. doi: 10.1016/j.jhin.2023.03.013. Epub 2023 Mar 23.
Despite adherence to standard protocols, residues including live micro-organisms may remain on the various surfaces of reprocessed flexible endoscopes. Prions are infectious proteins that are notoriously difficult to eliminate.
To test the potential of cold atmospheric plasma (CAP) for the decontamination of various surfaces of flexible endoscopes, measuring total proteins and prion residual infectivity as indicators of efficacy.
New PTFE endoscope channels and metal test surfaces spiked with test soil or prion-infected tissues were treated using different CAP-generating prototypes. Surfaces were examined for the presence of residues using very sensitive fluorescence epimicroscopy. Prion residual infectivity was determined using the wire implant animal model and a more sensitive cell infectivity assay.
A CAP jet applied perpendicularly at close range on flat test surfaces removed soil within 3 min, but left microscopic residues and failed to eliminate prion infectivity according to the wire implant animal assay. The longitudinal gas flow from CAP prototypes developed for the treatment of long channels led to the displacement and sedimentation of residual soil towards the distal end, when applied alone. Observations of the plasma inside glass tubes showed temporal and spatial heterogeneity within a limited range. After the standard enzymatic manual pre-wash, 'CAP-activated' gas effluents prevented prion transmission from treated endoscope channels according to the prion infectivity cell assay.
CAP shows promising results as a final step for decontamination of surgical surfaces. Optimizing CAP delivery could further enhance CAP efficacy, offering a safe, chemical-free alternative for the reprocessing of all luminal flexible endoscope surfaces.
尽管遵循了标准协议，但重新处理的软性内镜的各种表面仍可能残留活微生物。朊病毒是一种具有传染性的蛋白质，极难消除。
测试冷等离子体 (CAP) 对软性内镜各种表面消毒的潜力，以总蛋白和朊病毒残留感染性作为功效的指标。
使用不同的 CAP 产生原型处理新的聚四氟乙烯（PTFE）内镜通道和金属测试表面，这些表面沾有测试土壤或朊病毒感染组织。使用非常灵敏的荧光体视显微镜检查表面是否存在残留物。使用金属丝植入动物模型和更灵敏的细胞感染性测定法来确定朊病毒残留感染性。
在平面测试表面上垂直近距离应用 CAP 射流可在 3 分钟内清除土壤，但会留下微观残留物，并且根据金属丝植入动物试验未能消除朊病毒感染性。单独应用时，用于处理长通道的 CAP 原型产生的纵向气流会导致残留土壤向远端移动和沉淀。在玻璃管内观察等离子体显示出在有限范围内的时间和空间异质性。在标准酶手动预清洗后，“CAP 激活”气体流出物根据细胞朊病毒感染性测定法阻止了从处理过的内镜通道中朊病毒的传播。
CAP 作为外科表面消毒的最后步骤显示出有希望的结果。优化 CAP 输送可以进一步增强 CAP 的功效，为所有内腔软性内镜表面的再处理提供一种安全、无化学物质的替代方法。
