Diagnosis with Metagenomic Next-Generation Sequencing (mNGS) technology and real-time PCR for SARS-CoV-2 Omicron detection using various nasopharyngeal swabs in SARS-CoV-2 Omicron.

The SARS-CoV-2 Omicron variant, with the main subtypes BA.5.2 and BF.7 in China, led to off-target effects on the S and N genes from December 1, 2022, to January 31, 2023. The kits used for studying and developing these agents were not adequately and independently evaluated. It is important to verify the performance of commercial Real-Time quantitative PCR (RT-qPCR) tests. We conducted a clinical evaluation of two Real Time SARS-CoV-2 Omicron assays to verify their performance using various detection reagents and clinical specimens. We performed clinical evaluations of two existing Chinese SARS-CoV-2 Omicron RT-qPCR kits 2019-nCoV nucleic acid diagnostic kits (Fosun Biotechnology, National instrument registration 20203400299, Shanghai, China) and COVID-19 nucleic acid detection kits (eDiagnosis Biomedicine, National instrument registration 20203400212, Wuhan, China) and using BSD (Bondson) (Guangzhou Bondson Biotechnology Co. Ltd, batch number 2022101), quality controls provided by the inspection center and a large number of clinically confirmed specimens. The concordance rates for the Fosun and eDiagnosis kits were 95% and 100%, respectively. The detection limit for the Fosun and eDiagnosis kits was verified to be 300 copies/mL and 500 copies/mL. The Fosun assay exhibited the largest coefficient of variation (CV) for ORF1ab and N gene at the detection limit concentration (4.80%, 3.49%), whereas eDiagnosis showed a smaller CV (0.93%, 1.10%). In the reference product from the Hangzhou Clinical Laboratory Center test, it was found that Fosun had the lowest sensitivity of 93.47% and a specificity of 100%, while eDiagnosis exhibited 100% for both sensitivity and specificity. The lowest single target gene detection rate of Fosun reagents was 68.7% for the ORF1ab gene and 87.5% for the N gene, while eDiagnosis detection rate was 100%. Among the clinical group S specimens, the missed detection rate of the Fosun reagent was 10.9%, which was higher than the 3.9% of eDiagnosis. However, there was no significant difference in the clinical diagnostic efficiency of the two reagents. The ORF1ab and N assays of SARS-CoV-2 Omicron on the eDiagnosis platform yielded higher values compared to those on the Fosun platform. Consequently, the eDiagnosis kit has also been used as standard detection reagents. Considering that the Fosun reagent has a relatively low detection limit and targets three single genes, it is more advantageous as a confirmatory reagent for the new museum.

Li S ，Zhang Y ，Tong P ，Yang W ... -  《PLoS One》

Performance verification of five commercial RT-qPCR diagnostic kits for SARS-CoV-2.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has caused a global pandemic beginning in 2020, can be detected by reverse-transcription polymerase chain reaction (RT-PCR). However, owing to the urgent need for a large number of detection kits, the time spent researching and developing these kits has been shortened during the pandemic, and the kits that are being used commercially have not undergone full and independent evaluation. To ensure the accuracy of SARS-CoV-2 test results, performance verification of commercial Real-Time quantitative PCR (RT-qPCR) kits is required. The performance of five commercial RT-qPCR diagnostic kits for SARS-CoV-2 used in China was evaluated using a coronavirus disease 2019 (COVID-19) RNA liquid performance verification reference product-manufactured by Guangzhou Bondson (BDS) Biotechnology Co., Ltd.,Guangzhou, China-that uses droplet digital RT-PCR technology combined with fluorescence quantitative PCR. The five kits of Novel Coronavirus 2019-nCoV nucleic acid detection kit (RT-qPCR method) evaluated were Da An (Da An Gene Co., Ltd. of Sun Yat-sen University), Liferiver (Shanghai ZJ Bio-Tech Co., Ltd.), Kinghawk (Beijing Kinghawk Pharmaceutical Co., Ltd.), eDiagnosis (Wuhan Easy Diagnosis Biomedicine Co., Ltd.), and Maccura (Maccura Biotechnology Co., Ltd.). Performance verification criteria included the coincidence rate, limit of detection (LoD), cross-reactivity, precision, and anti-interference. Finally, through the BDS performance verification reference product kit, clinical samples are used to verify its clinical diagnostic efficacy. The coincidence rate was 100% for all kits except for Kinghawk, which was 95%. The LoD for Da An, eDiagnosis and Maccura was 250copies/mL, and it was 1000 copies/ml for Liferiver. Kinghawk was not able to detect its advertised LoD of 500 copies/ml. The cross-reactivity test results were all negative. Moreover, all kits had a coefficient of variation less than 5%; however, Liferiver showed the best precision. Da An, Liferiver, and eDiagnosis showed higher sensitivity to the nucleocapsid (N) gene than they did to the open reading frame (ORF) 1ab genes. Anti-interference results for all five kits were positive. The results of clinical diagnostic efficacy were that the specificity of the four kits was 1.000 (0.877-1.000), the sensitivity of Da An was 1.000 (0.850-1.000), Liferiver was 0.964 (0.798-0.998), Maccura was 0.893 (0.706-0.972), and eDiagnosis was 0.857 (0.664-0.953). All commercial RT-qPCR diagnostic kits for SARS-CoV-2 passed the BDS performance verification, except for Kinghawk (batch No:20200608113) which failed to detect the LoD of 500 copies/mL. Da An and Liferiver have excellent clinical diagnostic specificity and sensitivity. This study can provide guidance for the selection or optimization of RT-qPCR diagnostic test kits for SARS-CoV-2.

Yang M ，Cao S ，Liu Y ，Zhang Z ，Zheng R ，Li Y ，Zhou J ，Zong C ，Cao D ，Qin X ... -  《-》

Clinical Performance and Analytical Sensitivity of Three SARS-CoV-2 Nucleic Acid Diagnostic Tests.

Freire-Paspuel B ，Garcia-Bereguiain MA 《-》

Evaluation of seven commercial RT-PCR kits for COVID-19 testing in pooled clinical specimens.

There are more than 350 real-time polymerase chain reaction (RT-PCR) coronavirus disease-2019 (COVID-19) testing kits commercially available but these kits have not been evaluated for pooled sample testing. Thus, this study was planned to compare and evaluate seven commercially available kits for pooled samples testing. Diagnostic accuracy of (1) TRUPCR SARS-CoV-2 Kit (Black Bio), (2) TaqPath RT-PCR COVID-19 Kit (Thermo Fisher Scientific), (3) Allplex 2019-nCOV Assay (Seegene), (4) Patho detect COVID-19 PCR kit (My Lab), (5) LabGun COVID-19 RT-PCR Kit (Lab Genomics, Korea), (6) Fosun COVID-19 RT-PCR detection kit (Fosun Ltd.), (7) Real-time Fluorescent RT-PCR kit for SARS CoV-2 (BGI) was evaluated on precharacterised 40 positive and 10 negative COVID-19 sample pools. All seven kits detected all sample pools with low Ct values (<30); while testing weak positive pooled samples with high Ct value (>30); the TRUPCR Kit, TaqPath Kit, Allplex Assay, and BGI RT-PCR kit showed 100% sensitivity, specificity, and accuracy. However, the Fosun kit, LabGun Kit, and Patho detect kit could detect only 90%, 85%, and 75% of weakly positive samples, respectively. We conclude that all seven commercially available RT-PCR kits included in this study can be used for routine molecular diagnosis of COVID-19. However, regarding performing pooled sample testing, it might be advisable to use those kits that performed best regarding positive identification in samples' pool, that is TRUPCR SARS-CoV-2 Kit, TaqPath RT-PCR COVID-19 Kit, Allplex 2019-nCOV Assay, and BGI Real-time RT-PCR kit for detecting SARS CoV-2.

Garg A ，Ghoshal U ，Patel SS ，Singh DV ，Arya AK ，Vasanth S ，Pandey A ，Srivastava N ... -  《-》

Comparative evaluation of six nucleic acid amplification kits for SARS-CoV-2 RNA detection.

Wu S ，Shi X ，Chen Q ，Jiang Y ，Zuo L ，Wang L ，Jiang M ，Lin Y ，Fang S ，Peng B ，Wu W ，Liu H ，Zhang R ，Kwan PSL ，Hu Q ... -  《Annals of Clinical Microbiology and Antimicrobials》