PDF(Pubmed)
Abstract：
Background: Metagenomic sequencing has the potential to identify a wide range of pathogens in human tissue samples. Sarcoidosis is a complex disorder whose etiology remains unknown and for which a variety of infectious causes have been hypothesized. We sought to conduct metagenomic sequencing on cases of ocular and periocular sarcoidosis, none of them with previously identified infectious causes. Methods: Archival tissue specimens of 16 subjects with biopsies of ocular and periocular tissues that were positive for non-caseating granulomas were used as cases. Four archival tissue specimens that did not demonstrate non-caseating granulomas were also included as controls. Genomic DNA was extracted from tissue sections. DNA libraries were generated from the extracted genomic DNA and the libraries underwent next-generation sequencing. Results: We generated between 4.8 and 20.7 million reads for each of the 16 cases plus four control samples. For eight of the cases, we identified microbial pathogens that were present well above the background, with one potential pathogen identified for seven of the cases and two possible pathogens for one of the cases. Five of the eight cases were associated with bacteria ( Campylobacter concisus, Neisseria elongata, Streptococcus salivarius, Pseudopropionibacterium propionicum, and Paracoccus yeei), two cases with fungi ( Exophiala oligosperma, Lomentospora prolificans and Aspergillus versicolor) and one case with a virus (Mupapillomavirus 1). Interestingly, four of the five bacterial species are also part of the human oral microbiome. Conclusions: Using a metagenomic sequencing we identified possible infectious causes in half of the ocular and periocular sarcoidosis cases analyzed. Our findings support the proposition that sarcoidosis could be an etiologically heterogenous disease. Because these are previously banked samples, direct follow-up in the respective patients is impossible, but these results suggest that sequencing may be a valuable tool in better understanding the etiopathogenesis of sarcoidosis and in diagnosing and treating this disease.
摘要：
背景：宏基因组测序具有鉴定人体组织样本中多种病原体的潜力。结节病是一种复杂的疾病，其病因仍然未知，并且已经假设了多种感染原因。我们试图对眼部和眼周结节病病例进行宏基因组测序，他们都没有先前确定的传染性原因。方法：以16例受试者的档案组织标本为病例，对非干酪性肉芽肿阳性的眼部和眼周组织进行活检。还包括四个未显示非干酪样肉芽肿的档案组织标本作为对照。从组织切片中提取基因组DNA。从提取的基因组DNA产生DNA文库,并对文库进行下一代测序。结果:对于16个病例加4个对照样品中的每一个,我们产生了4.8到2070万个读数。对于八个案例，我们确定了微生物病原体存在于背景之上，其中7例确定了一种潜在病原体，其中1例确定了两种可能的病原体。8例中有5例与细菌有关（弯曲菌，长隆奈瑟菌,唾液链球菌，丙酸假丙酸杆菌,和Paracocusyeei)，2例真菌（Exophiala少精，长龙孢菌和杂色曲霉）和1例病毒（Mupapillomavirus1）。有趣的是,五种细菌中的四种也是人类口腔微生物组的一部分。结论：使用宏基因组测序，我们在分析的一半眼部和眼周结节病病例中确定了可能的感染原因。我们的发现支持结节病可能是病因异质性疾病的主张。因为这些是以前库存的样本，对各自的患者进行直接随访是不可能的，但这些结果表明，测序可能是一个有价值的工具，在更好地了解结节病的病因和诊断和治疗这种疾病。
