Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Sci Rep. 2022 Jan 11;12(1):505. doi: 10.1038/s41598-021-04538-4.
Current methods used for diagnosis of acute infection of pathogens rely on detection of nucleic acids, antigens, or certain classes of antibodies such as IgM. Here we report a virus enzyme assay as an alternative to these methods for detection of acute viral infection. In this method, we used a luciferin derivative as the substrate for detection of the enzyme activity of influenza viral neuraminidase as a means for diagnosis of influenza. The resulting commercial test, the qFLU Dx Test, uses a different supply chain that does not compete with those for the current tests. The assay reagents were formulated as a master mix that accommodated both the neuraminidase and luciferase reactions, thereby enabling rapid and prolonged production of stable light signal in the presence of influenza virus in the sample. The assay was evaluated using depository throat swab specimens. As expected, the assay exhibited similar detection rates for all influenza types and subtypes except for A(H7N9), which exhibited lower detection rate due to lower viral titer in the specimens. When throat swab specimens were diluted with the sample buffer of the test kit and tested with the qFLU Dx Test. The sensitivity and specificity were 82.41% (95% confidence interval: 79.66-85.84%) and 95.39% (95% confidence interval: 94.32-96.46%), respectively, for these diluted specimens in comparison to a real-time polymerase chain reaction assay. The uniqueness of the qFLU Dx Test as an enzymatic assay makes it highly complementary with currently available methods.
目前用于诊断病原体急性感染的方法依赖于核酸、抗原或某些类别的抗体（如 IgM）的检测。在这里，我们报告了一种病毒酶测定法，作为这些方法的替代方法，用于检测急性病毒感染。在这种方法中，我们使用荧光素衍生物作为流感病毒神经氨酸酶的酶活性检测的底物，作为诊断流感的一种手段。由此产生的商业测试，即 qFLU Dx 测试，使用了不同的供应链，不会与当前测试竞争。该测定试剂被配制为一个主混合物，容纳神经氨酸酶和荧光酶反应，从而在样本中存在流感病毒的情况下，能够快速且长时间产生稳定的光信号。该测定法使用储库咽喉拭子标本进行评估。正如预期的那样，该测定法对所有流感类型和亚型的检测率都相似，除了 A(H7N9)，由于标本中病毒滴度较低，其检测率较低。当咽喉拭子标本用试剂盒的样品缓冲液稀释并与 qFLU Dx 测试一起测试时，与实时聚合酶链反应测定法相比，这些稀释标本的灵敏度和特异性分别为 82.41%（95%置信区间：79.66-85.84%）和 95.39%（95%置信区间：94.32-96.46%）。qFLU Dx 测试作为一种酶测定法的独特性使其与当前可用的方法高度互补。
