Surface microbiome

Background. Antimicrobial surfaces incorporated to high-touch public areas are used as a passive intervention to reduce surface microbial load and reduce the spread of infections. However, usually such surfaces lack a proof on their antimicrobial activity in real use conditions and against a wider variety of microbes. This study evaluated the real-world performance of copper, TiO2-, silver- and quaternary ammonium compound (SiQAC)-based surfaces, which are commercially available and have proven antibacterial activity in lab tests. The surfaces were introduced to five study sites in diverse environments to collect data on bacterial load, community structure and taxonomical profile over several months.Results. Copper surfaces introduced to shopping basket handles consistently exhibited the strongest antimicrobial performance, with significant reductions in aerobic bacterial counts and bacterial DNA, accompanied by clear shifts in microbial community composition. These shifts included reduction of several human-associated and opportunistic taxa and relative enrichment of environmentally resilient, stress-tolerant genera. TiO2-based photocatalytic coating reduced bacterial load in kindergarten tables under field conditions but did not significantly alter overall community structure. Silver-based surfaces on university campus tables showed minimal effects on microbial load and composition despite confirmed antibacterial activity in laboratory testing. Analogously to silver, SiQAC-based coating despite being active in lab conditions showed no decrease in bacterial load in real use conditions. When applied onto cafeteria and animal clinic tables SiQAC coating displayed context-dependent effects, with modest, genus-specific changes and increased richness in a high-contact cafeteria environment, but no significant impact in a low-biomass animal clinic setting. Viability based analysis revealed that on most of the surfaces a notable fraction of detected microbial DNA originated from non-viable cells. Conclusions. This multisite field study demonstrates that the real-world performance of antimicrobially coated surfaces is strongly context dependent and cannot be reliably predicted from laboratory testing alone. Moreover, to understand the effect of antimicrobial coatings on surface microbial communities, real-use monitoring is needed.

将抗菌表面应用于高频接触的公共区域，作为被动干预手段以降低表面微生物负载并减少感染传播。然而，此类表面通常尚未验证其在实际使用场景下以及针对更多种类微生物的抗菌活性。本研究评估了铜基、二氧化钛（TiO₂）基、银基以及季铵化合物（quaternary ammonium compound, SiQAC）基抗菌表面的实际使用性能，这类表面均已实现商业化，且在实验室测试中被证实具有抗菌活性。研究将这些表面部署于5个不同环境的研究点位，在数月内收集其表面细菌负载、群落结构及分类学特征相关数据。
部署于购物篮把手的铜基表面始终表现出最强的抗菌性能：需氧细菌计数与细菌DNA量均显著降低，同时微生物群落组成发生明显改变。此类改变包括多种与人类相关的机会性分类群丰度下降，以及环境适应性强、耐胁迫的菌属相对富集。二氧化钛（TiO₂）基光催化涂层在实地场景中可降低幼儿园课桌椅表面的细菌负载，但未显著改变整体群落结构。尽管实验室测试已证实银基表面具有抗菌活性，但部署于大学校园课桌椅的银基表面对微生物负载与群落组成仅产生极微弱的影响。与银基表面类似，尽管SiQAC基涂层在实验室条件下具有抗菌活性，但在实际使用场景中未使细菌负载出现降低。当将SiQAC基涂层应用于食堂与动物诊所的课桌椅表面时，其效果呈现环境依赖性：在高接触频率的食堂环境中，仅引发属水平的小幅变化并使群落丰富度提升，但在低生物量的动物诊所场景中未产生显著影响。基于细胞活性的分析显示，在大多数测试表面上，检测到的微生物DNA中有相当一部分来自无活性的细胞。
本多点位实地研究表明，抗菌涂层表面的实际使用性能具有极强的环境依赖性，无法仅通过实验室测试可靠预测。此外，若要阐明抗菌涂层对表面微生物群落的影响，需开展实际使用场景下的监测工作。