Abstract
As the SARS-CoV-2 virus evolves, mutations may result in diminished sensitivity to qRT-PCR diagnostic assays. We investigated four polymorphisms circulating in the SARS-CoV-2 Delta lineage that result in N gene target failure (NGTF) on the TaqPath COVID-19 Combo Kit. These mutations were detected from the SARS-CoV-2 genome sequences that matched with the diagnostic assay results of saliva specimens. Full length N genes from the samples displaying NGTF were cloned into plasmids and assayed using three SARS-CoV-2 qRT-PCR assays. These constructs resulted in reduced sensitivity to the TaqPath COVID-19 Combo Kit compared to the controls (mean C t differences of 3.06, 7.70, 12.46, and 14.12), but were detected equivalently on the TaqPath COVID-19 Fast PCR Combo 2.0 or CDC 2019_nCoV_N2 assays. This work highlights the importance of genomic sequencing to monitor circulating mutations and provide guidance in improving diagnostic assays.
Keywords: COVID-19; N gene dropout; SARS-CoV-2; delta variant; qRT-PCR.
【저자키워드】 COVID-19, SARS-CoV-2, delta variant, qRT-PCR., N gene dropout, 【초록키워드】 Mutation, qRT-PCR, polymorphism, diagnostic, Delta, SARS-CoV-2 virus, delta variant, sensitivity, PCR, CDC, Lineage, Control, N gene, PCR assays, Guidance, genomic sequencing, TaqPath, Plasmid, SARS-CoV-2 genome sequences, sequence, circulating, N genes, plasmids, MONITOR, saliva specimens, SARS-CoV-2 qRT-PCR, highlight, cloned, assays, investigated, reduced, displaying, the SARS-CoV-2, the SARS-CoV-2 genome, the SARS-CoV-2 virus, 【제목키워드】 Delta,