Horiba Kazuhiro, Torii Yuka, Okumura Toshihiko, Takeuchi Suguru, Suzuki Takako, Kawada Jun-Ichi, Muramatsu Hideki, Takahashi Yoshiyuki, Ogi Tomoo, Ito Yoshinori
Department of Genetics, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan.
Department of Human Genetics and Molecular Biology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Open Forum Infect Dis. 2021 May 4;8(11):ofab223. doi: 10.1093/ofid/ofab223. eCollection 2021 Nov.
Febrile neutropenia (FN) is a frequent complication in immunocompromised patients. However, causative microorganisms are detected in only 10% of patients. This study aimed to detect the microorganisms that cause FN using next-generation sequencing (NGS) to identify the genome derived from pathogenic microorganisms in the bloodstream. Here, we implemented a metagenomic approach to comprehensively analyze microorganisms present in clinical samples from patients with FN.
FN is defined as a neutrophil count <500 cells/µL and fever ≥37.5°C. Plasma/serum samples of 112 pediatric patients with FN and 10 patients with neutropenia without fever (NE) were sequenced by NGS and analyzed by a metagenomic pipeline, PATHDET.
The putative pathogens were detected by NGS in 5 of 10 FN patients with positive blood culture results, 15 of 87 FN patients (17%) with negative blood culture results, and 3 of 8 NE patients. Several bacteria that were common in the oral, skin, and gut flora were commonly detected in blood samples, suggesting translocation of the human microbiota to the bloodstream in the setting of neutropenia. The cluster analysis of the microbiota in blood samples using NGS demonstrated that the representative bacteria of each cluster were mostly consistent with the pathogens in each patient.
NGS technique has great potential for detecting causative pathogens in patients with FN. Cluster analysis, which extracts characteristic microorganisms from a complex microbial population, may be effective to detect pathogens in minute quantities of microbiota, such as those from the bloodstream.
发热性中性粒细胞减少症（FN）是免疫功能低下患者常见的并发症。然而，仅10%的患者能检测到致病微生物。本研究旨在使用下一代测序（NGS）检测导致FN的微生物，以识别血液中致病微生物的基因组。在此，我们采用宏基因组学方法全面分析FN患者临床样本中存在的微生物。
FN定义为中性粒细胞计数<500个细胞/μL且发热≥37.5°C。对112例儿童FN患者和10例无发热的中性粒细胞减少症（NE）患者的血浆/血清样本进行NGS测序，并通过宏基因组学流程PATHDET进行分析。
在血培养结果阳性的10例FN患者中有5例通过NGS检测到推定病原体，血培养结果阴性的87例FN患者中有15例（17%）检测到，8例NE患者中有3例检测到。血液样本中常见检测到口腔、皮肤和肠道菌群中常见的几种细菌，提示在中性粒细胞减少的情况下人类微生物群易位至血液。使用NGS对血液样本中的微生物群进行聚类分析表明，每个聚类的代表性细菌大多与各患者的病原体一致。
NGS技术在检测FN患者的致病病原体方面具有巨大潜力。从复杂微生物群体中提取特征微生物的聚类分析可能有效检测微量微生物群中的病原体，如血液中的病原体。
