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2020-12
2020年11月09日,nature medicine 杂志(if:36.13)发表《rapid pathogen detection by metagenomic next - generation sequencing of infected body fluids》研究文章,探讨新一代宏基因组测序对感染体液快速进行病原检测的应用,该研究入组160名急性病患者,并收集了182种体液进行mngs检测,并与培养法、pcr、纳米孔测序等方法进行微生物学测试的对比。
我们使用体液中的无细胞dna进行了mngs测试,以鉴定病原体。使用两种测序平台对160名急性病患者的182种体液的mngs测试性能进行了评估,并与使用培养物、16s细菌pcr和/或28s-内部转录核糖体基因间隔子(28s-its)真菌pcr的微生物学测试进行对比。通过illumina测序,细菌的检测灵敏度和检测特异性分别为79%和91%,真菌为91%和89%;通过纳米孔测序,细菌分别为75%和81%,真菌为91%和100%。在12例培养/ pcr阴性体液但最终被确诊为感染的患者中,有7例(58%)是mngs阳性。实时计算分析可通过中值50分钟测序和6小时样品到应答时间的纳米孔测序实现病原体鉴定。快速的mngs测试是诊断体液未知感染的潜在工具。
图a:mngs体液分析工作流程示意图
a, schematic of mngs body fluid analysis workflow. the clinical gold standard consisted of aggregated results from cultures, bacterial 16s pcr and/or fungal 28s–its pcr, while the composite standard also included confirmatory digital pcr with sanger sequencing and clinical adjudication. for nanopore sequencing in <6 h, 40–60 min are needed for nucleic acid extraction, 2–2.5 h for mngs library preparation, 1 h for nanopore 1d library preparation and 1 h for nanopore sequencing and analysis.
(临床金标准由培养物、细菌16spcr和/或真菌28s-itspcr的共同结果,而复核标准还包括与sanger的验证性数字pcr测序和临床诊断。 对于< 6 h的纳米孔测序,核酸提取需40~60 min,mngs文库制备需2~ 2.5 h,纳米孔1d 建库需1 h,纳米孔测序分析需1 h。)
图b:研究中包括的182例体液样本的分析工作流程
b, analysis workflow for the 182 body fluid samples included in the study. 170 samples were included in the accuracy assessment while 12 samples collected from patients with a clinical diagnosis of infection but negative microbiological testing were included for mngs analysis. the pie chart displays the body fluid sample types analyzed in the study.
(在准确性评估中包括170个样本,从临床诊断感染的患者中收集的12个样本,但对阴性微生物样本进行了mngs检测。饼图显示研究中分析的体液样本类型。)
图c:相对于培养的mngs测试的时机
c, timing for mngs testing relative to culture. whereas culture-based pathogen identification can take days to weeks, mngs testing using nanopore or illumina sequencing platforms has an overall turnaround time of 5–24 h.
(基于培养的病原体鉴定可能需要几天到几周,而使用纳米孔或illumina测序平台进行mngs测试的总体运行时间为5-24小时。)
参考文献:[1]. rapid pathogen detection by metagenomic next-generation sequencing of infected body fluids.[j]. nature medicine,2020.