Coelho Fabiana Fioravante, da Silva Miriam Aparecida, Lopes Thiciany Blener, Polatto Juliana Moutinho, de Castro Natália Salazar, Andrade Luis Adan Flores, Lourenço Karine Lima, Sato Hugo Itaru, de Carvalho Alex Fiorini, Coelho Helena Perez, Bagno Flávia Fonseca, Luz Daniela, Viala Vincent Louis, Cattony Pedro Queiroz, Melo Bruna de Sousa, Moro Ana Maria, Quintilio Wagner, Barbosa Ana Paula, Bomfim Camila Gasque, Soares Camila Pereira, Guzzo Cristiane Rodrigues, Fonseca Flavio Guimarães, Durigon Edison Luiz, Gazzinelli Ricardo Tostes, Ribeiro Teixeira Santuza M, Piazza Roxane Maria Fontes, Fernandes Ana Paula
Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Brazil.
Hospital da Polícia Militar de Minas Gerais, Polícia Militar de Minas Gerais, Belo Horizonte 30110-013, Brazil.
Microorganisms. 2023 Sep 28;11(10):2422. doi: 10.3390/microorganisms11102422.
SARS-CoV-2 diagnostic tests have become an important tool for pandemic control. Among the alternatives for COVID-19 diagnosis, antigen rapid diagnostic tests (Ag-RDT) are very convenient and widely used. However, as SARS-CoV-2 variants may continuously emerge, the replacement of tests and reagents may be required to maintain the sensitivity of Ag-RDTs. Here, we describe the development and validation of an Ag-RDT during an outbreak of the Omicron variant, including the characterization of a new monoclonal antibody (anti-DTC-N 1B3 mAb) that recognizes the Nucleocapsid protein (N). The anti-DTC-N 1B3 mAb recognized the sequence TFPPTEPKKDKKK located at the C-terminus of the N protein of main SARS-CoV-2 variants of concern. Accordingly, the Ag-RDT prototypes using the anti-DTC-N 1B3 mAB detected all the SARS-CoV-2 variants-Wuhan, Alpha, Gamma, Delta, P2 and Omicron. The performance of the best prototype (sensitivity of 95.2% for samples with Ct ≤ 25; specificity of 98.3% and overall accuracy of 85.0%) met the WHO recommendations. Moreover, results from a patients' follow-up study indicated that, if performed within the first three days after onset of symptoms, the Ag-RDT displayed 100% sensitivity. Thus, the new mAb and the Ag-RDT developed herein may constitute alternative tools for COVID-19 point-of-care diagnosis and epidemiological surveillance.
严重急性呼吸综合征冠状病毒2（SARS-CoV-2）诊断检测已成为疫情防控的重要工具。在2019冠状病毒病（COVID-19）诊断方法中，抗原快速诊断检测（Ag-RDT）非常便捷且应用广泛。然而，由于SARS-CoV-2变异株可能不断出现，可能需要更换检测方法和试剂以维持Ag-RDT的敏感性。在此，我们描述了在奥密克戎变异株疫情期间一种Ag-RDT的开发与验证，包括一种识别核衣壳蛋白（N）的新型单克隆抗体（抗-DTC-N 1B3 mAb）的特性鉴定。抗-DTC-N 1B3 mAb识别主要关注的SARS-CoV-2变异株N蛋白C端的序列TFPPTEPKKDKKK。因此，使用抗-DTC-N 1B3 mAb的Ag-RDT原型检测出了所有SARS-CoV-2变异株——武汉株、阿尔法株、伽马株、德尔塔株、P2株和奥密克戎株。最佳原型的性能（Ct≤25的样本敏感性为95.2%；特异性为98.3%，总体准确率为85.0%）符合世界卫生组织的建议。此外，一项患者随访研究结果表明，如果在症状出现后的前三天内进行检测，该Ag-RDT的敏感性为100%。因此，本文开发的新型单克隆抗体和Ag-RDT可能构成COVID-19即时诊断和流行病学监测的替代工具。
