Archaea on human skin: AOA as integral members of the human skin microbiome

[includes the data of cohort C archaea specific] Ammonia oxidizing archaea (AOA) have been repeatedly detected in the human skin microbiome through molecular and biochemical analyses, yet their persistence, physiology, and adaptations remain poorly understood. Here, we describe two cultivated strains, Candidatus Nitrosocosmicus epidermidis and Nitrosocosmicus unguis, isolated from human skin samples. These strains grow on ammonia and urea as sole energy sources. Genomic islands and expanded gene families in their genomes testify to the capacity of colonizing skin, based on specific interactions with host proteins and signalling cascades and distinct them from their close relatives from soil. Molecular signatures of Nitrosocosmicus ssp. were consistently identified on individuals in cross-sectional and longitudinal cohorts (n=47) with a higher prevalence in sebaceous areas. Co-occurrence network patterns with specific bacteria reinforce the observation that AOA of the genus Nitrosocosmicus form a stable component of the healthy skin and represent emerging commensals in the human microbiome.

[包含特定C队列古菌相关数据] 氨氧化古菌（Ammonia oxidizing archaea, AOA）已通过分子与生化分析手段在人类皮肤微生物组中被多次检出，但其定植持久性、生理特性与适应机制仍有待深入阐明。本研究报道两株从人类皮肤样本中分离获得的可培养菌株：*Candidatus Nitrosocosmicus epidermidis* 与 *Nitrosocosmicus unguis*。该两株菌能够以氨与尿素作为唯一能源物质进行生长。其基因组中存在的基因组岛与扩张基因家族，证实了它们具备皮肤定植能力：这类菌株通过与宿主蛋白及信号级联反应的特异性相互作用，与土壤来源的近缘菌株形成显著分化。在横断面与纵向队列（n=47）的受试者中，我们持续检测到*Nitrosocosmicus* 亚种的分子标记特征，且该类群在皮脂腺丰富区域的检出率更高。与特定细菌的共现网络模式进一步佐证了上述结论：*Nitrosocosmicus* 属的氨氧化古菌是健康皮肤微生物组的稳定组成部分，同时也是人类微生物组中一类新兴的共生类群。