Educational facilities serve as community hubs and consequently hotspots for exposure to pathogenic microorganisms. Therefore, it is of critical importance to understand processes shaping the indoor microbiomes in educational facilities to protect public health by reducing potential exposure risks of students and the broader community. In this study, the indoor surface bacterial microbiomes were characterized in two multifunctional university buildings with contrasting levels of human occupancy, of which one was recently constructed with minimal human occupancy while the other had been in full operation for six years. Higher levels of human occupancy in the older building were shown to result in greater microbial abundance in the indoor environment and greater proportion of the indoor surface bacterial microbiomes contributed from human-associated microbiota, particularly the skin microbiota. It was further revealed that human-associated microbiota had greater influence on the indoor surface bacterial microbiomes in areas of high occupancy than areas of low occupancy. Consistent with minimal impact from human occupancy in a new construction, the indoor microbiomes in the new building exhibited significantly lower influence from human-associated microbiota than in the older building, with microbial taxa originating from soil and plants representing the dominant constituents of the indoor surface bacterial microbiomes. In contrast, microbial taxa in the older building with extensive human occupancy were represented by constituents of the human microbiota, likely from occupants. These findings provide insights into processes shaping the indoor microbiomes which will aid the development of effective strategies to control microbial exposure risks of occupants in educational facilities.

教育设施是社区中心，因此也是接触病原微生物的热点。因此，了解塑造教育设施室内微生物组的过程对于通过减少学生和更广泛社区的潜在接触风险来保护公众健康至关重要。在这项研究中，室内表面细菌微生物群落在两座多功能大学建筑中进行了表征，这些建筑具有对比鲜明的人类居住水平，其中一座是最近建造的，人类占用最少，而另一座已经全面运营六年。研究表明，老建筑中较高的人类入住率会导致室内环境中微生物的丰度增加，并且室内表面细菌微生物群的比例更大，这些微生物群来自与人类相关的微生物群，尤其是皮肤微生物群。进一步表明，与人相关的微生物群在高占用率区域比低占用率区域对室内表面细菌微生物组的影响更大。与新建筑中人类入住的影响最小相一致，新建筑中的室内微生物群受到人类相关微生物群的影响明显低于旧建筑，微生物类群来自土壤和植物，代表了室内表面的主要成分细菌微生物组。相比之下，在人类广泛居住的旧建筑中，微生物类群由人类微生物群的成分代表，可能来自居住者。这些发现提供了对塑造室内微生物组的过程的深入了解，这将有助于制定有效的策略来控制教育设施中居住者的微生物暴露风险。