National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, State Key Laboratory of Infectious Disease Prevention and Control, Beijing, China.
Institute for Infectious Disease and Endemic Disease Control, Beijing Center for Disease Prevention and Control, Beijing Research Center for Preventive Medicine, Beijing Key Laboratory of Diagnostic and Traceability Technologies for Food Poisoning, Beijing, China.
Microbiol Spectr. 2021 Dec 22;9(3):e0126721. doi: 10.1128/Spectrum.01267-21. Epub 2021 Nov 17.
The objective of this study was to construct a novel strategy for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants using multiplex PCR-mass spectrometry minisequencing technique (mPCR-MS minisequencing). Using the nucleic acid sequence of a SARS-CoV-2 nonvariant and a synthetic SARS-CoV-2 variant-carrying plasmid, a matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) method based on the single-base mass probe extension of multiplex PCR amplification products was established to detect 9 mutation types in 7 mutated sites (HV6970del, N501Y, K417N, P681H, D614G, E484K, L452R, E484Q, and P681R) in the receptor-binding domain of the spike protein of SARS-CoV-2 variants. Twenty-one respiratory tract pathogens (9 bacteria and 12 respiratory viruses) and nucleic acid samples from non-COVID-19 patients were selected for specific validation. Twenty samples from COVID-19 patients were used to verify the accuracy of this method. The 9 mutation types could be detected simultaneously by triple PCR amplification coupled with MALDI-TOF MS. SARS-CoV-2 and six variants, B.1.1.7 (Alpha), B.1.351 (Beta), B.1.429 (Epsilon), B.1.526 (Iota), P.1 (Gamma) and B.1.617.2 (Delta), could be identified. The detection limit for all 9 sites was 1.5 × 10 copies. The specificity of this method was 100%, and the accuracy of real-time PCR cycle threshold () values less than 27 among positive samples was 100%. This method is open and extensible, and can be used in a high-throughput manner, easily allowing the addition of new mutation sites as needed to identify and track new SARS-CoV-2 variants as they emerge. mPCR-MS minisequencing provides a new detection option with practical application value for SARS-CoV-2 and its variant infection. The emergence of SARS-CoV-2 variants is the key factor in the second wave of the COVID-19 pandemic. An all-in-one SARS-CoV-2 variant identification method based on a multiplex PCR-mass spectrometry minisequencing system was developed in this study. Six SARS-CoV-2 variants (Alpha, Beta, Epsilon, Iota, Gamma, and Delta) can be identified simultaneously. This method can not only achieve the multisite simultaneous detection that cannot be realized by PCR coupled with first-generation sequencing technology and quantitative PCR (qPCR) technology but also avoid the shortcomings of time-consuming, high-cost, and high technical requirements of whole-genome sequencing technology. As a simple screening assay for monitoring the emergence and spread of SARS-CoV-2 and variants, mPCR-MS minisequencing is expected to play an important role in the detection and monitoring of SARS-CoV-2 infection as a supplementary technology.
本研究旨在构建一种用于检测严重急性呼吸综合征冠状病毒 2 型(SARS-CoV-2)变体的新策略,采用多重 PCR-质谱小测序技术(mPCR-MS minisequencing)。使用 SARS-CoV-2 非变体的核酸序列和合成的携带 SARS-CoV-2 变体的质粒,建立了一种基于基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)的方法,基于多重 PCR 扩增产物的单碱基质量探针延伸,用于检测 Spike 蛋白受体结合域中 7 个突变位点(HV6970del、N501Y、K417N、P681H、D614G、E484K、L452R、E484Q 和 P681R)中的 9 种突变类型。选择 21 种呼吸道病原体(9 种细菌和 12 种呼吸道病毒)和非 COVID-19 患者的核酸样本进行特异性验证。用 20 份 COVID-19 患者样本验证了该方法的准确性。通过三重 PCR 扩增与 MALDI-TOF MS 可同时检测 9 种突变类型。可以识别 SARS-CoV-2 和 6 种变体,B.1.1.7(Alpha)、B.1.351(Beta)、B.1.429(Epsilon)、B.1.526(Iota)、P.1(Gamma)和 B.1.617.2(Delta)。所有 9 个位点的检测限为 1.5×10 拷贝。该方法的特异性为 100%,实时 PCR 循环阈值(Ct)值小于 27 的阳性样本的准确性为 100%。该方法是开放和可扩展的,可采用高通量方式,可根据需要轻松添加新的突变位点,以识别和跟踪新出现的 SARS-CoV-2 变体。mPCR-MS minisequencing 为 SARS-CoV-2 及其变体感染提供了一种具有实用价值的新检测方法。SARS-CoV-2 变体的出现是 COVID-19 大流行第二波的关键因素。本研究建立了一种基于多重 PCR-质谱小测序系统的 SARS-CoV-2 变体一体化鉴定方法,可同时鉴定 6 种 SARS-CoV-2 变体(Alpha、Beta、Epsilon、Iota、Gamma 和 Delta)。该方法不仅可以实现 PCR 与第一代测序技术和定量 PCR(qPCR)技术无法实现的多靶点同时检测,而且还可以避免全基因组测序技术耗时、成本高、技术要求高的缺点。作为一种用于监测 SARS-CoV-2 及其变体出现和传播的简单筛选检测方法,mPCR-MS minisequencing有望作为一种补充技术,在 SARS-CoV-2 感染的检测和监测中发挥重要作用。