Clinical Comparative Evaluation of the LabTurboTM AIO® Reverse Transcription-Polymerase Chain Reaction and World Health Organization-Recommended Assays for the Detection of Emerging SARS-CoV-2 Variants of Concern

Abstract

Purpose: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent behind coronavirus disease-2019 (COVID-19). Single-plex reverse transcription-polymerase chain reaction (RT-PCR)-based assays are widely used for COVID-19 detection but exhibit decreased sensitivity and specificity in detecting the rapidly spreading SARS-CoV-2 variants; in contrast, multiplex RT-PCR reportedly yields better results. Here, we aimed at comparatively analyzing the clinical performance of the LabTurbo^TM AIO COVID-19 RNA testing kit, a multiplex quantitative RT-PCR kit, including a three-target (E, N1, and RNase P), single-reaction, triplex assay used for SARS-CoV-2 detection, with that of the WHO-recommended RT-PCR assay.

Materials and methods: Residual, natural, nasopharyngeal swabs obtained from universal transport medium specimens at SARS-CoV-2 testing centers (n = 414) were collected from May to October 2021. For SARS-CoV-2 qRT-PCR, total viral nucleic acid was extracted. The limit of detection (LOD) and the comparative clinical performances of the LabTurbo^TM AIO COVID-19 RNA kit and the WHO-recommended RT-PCR assay were assessed. Statistical analysis of the correlation was performed and results with R² values >0.9 were considered to be highly correlated.

Results: The LOD of the LabTurbo^TM AIO COVID-19 RNA kit was 9.4 copies/reaction for the target genes N1 and E. The results obtained from 102 SARS-CoV-2-positive and 312 SARS-CoV-2-negative samples showed 100% correlation with previous WHO-recommended RT-PCR assay results.

Conclusion: Multiplex qRT-PCR is a critical tool for detecting unknown pathogens and employs multiple target genes. The LabTurbo^TM AIO COVID-19 RNA testing kit provides an effective and efficient assay for SARS-CoV-2 detection and is highly compatible with SARS-CoV-2 variants.

Keywords: COVID-19; COVID-19 RNA testing kit; SARS-CoV-2; multiplex qRT-PCR; variants of concern.

Figure 1

Correlation between results obtained using LabTurbo^TM AIO COVID-19 RNA testing assay and WHO-recommended assay with the Rotor-Gene-Q real-time PCR instrument. (A) SARS-CoV-2 N1 versus RdRp screening results. (B) SARS-CoV-2 E screening results; correlation between results obtained using LabTurbo^TM AIO COVID-19 RNA testing assay and WHO-recommended assay with the Roche LightCycler96 instrument. (C) Shows SARS-CoV-2 N1 versus RdRp gene results. (D) Shows SARS-CoV-2 E gene results.