The increase in antimicrobial resistance is of worldwide concern. Surrogate tracers attempt to simulate microbial transmission by avoiding the infectious risks associated with live organisms. We evaluated silica nanoparticles with encapsulated DNA (SPED) as a new promising surrogate tracer in healthcare. SPED and Escherichia coli were used to implement three experiments in simulation rooms and a microbiology laboratory in 2017–2018. Experiment 1 investigated the transmission behaviour of SPED in a predefined simulated patient-care scenario. SPED marked with 3 different DNA sequences (SPED1-SPED3) were introduced at 3 different points of the consecutive 13 touch sites of a patient-care scenario that was repeated 3 times, resulting in a total of 288 values. Experiment 2 evaluated SPED behaviour following hand cleaning with water and soap and alcohol-based handrub. Experiment 3 compared transfer dynamics of SPED versus E. coli in a laboratory using a gloved finger touching two consecutive sites on a laminate surface after a first purposefully contaminated site. Experiment 1: SPED adhesiveness on bare skin after a hand-to-surface exposure was high, leading to a dissemination of SPED1–3 on all consecutive surface materials with a trend of decreasing recovery rates, also reflecting touching patterns in concordance with contaminated fingers versus palms. Experiment 2: Hand washing with soap and water resulted in a SPED reduction of 96%, whereas hand disinfection led to dispersal of SPED from the palm to the back of the hand. Experiment 3: SPED and E. coli concentration decreased in parallel with each transmission step – with SPED showing a trend for less reduction and variability. SPED represent a convenient and safe instrument to simulate pathogen spread by contact transmission simultaneously from an infinite number of sites. They can be further developed as a central asset for successful infection prevention in healthcare.

中文翻译：

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带有封装 DNA (SPED) 的二氧化硅纳米粒子——一种用于医疗保健中微生物传播的新型替代示踪剂。

抗菌素耐药性的增加引起了全世界的关注。替代示踪剂试图通过避免与活生物体相关的感染风险来模拟微生物传播。我们评估了带有封装 DNA (SPED) 的二氧化硅纳米粒子作为医疗保健中一种新的有前途的替代示踪剂。2017-2018 年，使用 SPED 和大肠杆菌在模拟室和微生物实验室进行了三个实验。实验 1 在预定义的模拟病人护理场景中研究了 SPED 的传输行为。在重复 3 次的患者护理场景的连续 13 个接触点的 3 个不同点引入标有 3 个不同 DNA 序列（SPED1-SPED3）的 SPED，共产生 288 个值。实验 2 评估了用水、肥皂和含酒精的洗手液洗手后的 SPED 行为。实验 3 在实验室中比较了 SPED 与大肠杆菌的转移动力学，使用戴手套的手指在第一个故意污染的部位后触摸层压板表面上的两个连续部位。实验 1：手接触表面后，裸露皮肤上的 SPED 粘附性很高，导致 SPED1-3 在所有连续的表面材料上传播，恢复率呈下降趋势，这也反映了与受污染手指相一致的触摸模式手掌。实验 2：用肥皂和水洗手导致 SPED 降低 96%，而手部消毒导致 SPED 从手掌扩散到手背。实验 3：SPED 和 E。大肠杆菌浓度与每个传播步骤同时下降——SPED 显示出减少和变异性减少的趋势。SPED 代表了一种方便且安全的工具，可以模拟通过接触传播同时从无限数量的地点传播的病原体。它们可以进一步发展为医疗保健中成功预防感染的核心资产。