RT-LAMP assay for rapid detection of the R203M mutation in SARS-CoV-2 Delta variant. Issue 1 (31st December 2022)

• Record Type: Journal Article
• Authors: Yang, Jianing; Hu, Xuejiao; Wang, Wenzhuo; Yang, Yujing; Zhang, Xinqiang; Fang, Wei; Zhang, Lei; Li, Shan; Gu, Bing
• Is Part Of: Emerging microbes & infections. Volume 11:Issue 1(2022)
• Page Start: 978
• Page End: 987
• Publication Date: 2022-12-31
• Subjects: SARS-CoV-2 -- Delta variant -- R203M mutation -- RT-LAMP -- rapid diagnosis; Medical microbiology -- Periodicals; Communicable diseases -- Periodicals; Infection -- Periodicals; 616.9041
• DOI: 10.1080/22221751.2022.2054368
• Languages: English
• ISSNs: 2222-1751

Abstract

ABSTRACT: The highly infectious Delta variant strain of SARS-CoV-2 remains globally dominant and undermines COVID-19 vaccines. Rapid detection of the Delta variant is crucial for the identification and quarantine of infected individuals. In this study, our aim was to design and validate a genotyping RT-LAMP method to detect Delta variants specifically. R203M in the N gene of SARS-CoV-2 was chosen as the Delta variant-specific mutation for genotyping. To target the R203M-harboring region and the conserved sequence of the N gene, two sets of primers were designed, and a Cq (quantification cycle) ratio-based RT-LAMP for SARS-CoV-2 and R203M detection was developed by analyzing the significant discrepancy in amplification efficiency of the two sets of primers. We validated the RT-LAMP method on 498 clinical specimens in parallel with RT-qPCR, and 84 Delta variants from 198 positive samples were determined by sequencing. Compared with traditional RT-qPCR analyses, RT-LAMP appears to be 100% accurate in detecting SARS-CoV-2 clinical samples. RT-LAMP has a good ability to distinguish between Delta and non-Delta variants under a Cq ratio threshold of 1.80. Furthermore, the AUC (area under the curve) of this method was 1.00; the sensitivity, specificity and accuracy were all 100%. In summary, we have proposed a rapid, accurate and cost-effective RT-LAMP method to detect SARS-CoV-2 and Delta variants, which may facilitate the surveillance of COVID-19.