Biology subjects

Zhen, W.

Publications and source records attributed to Zhen, W..

3 recordsLinked to original sources

bioRxiv2020

Design of a Novel Multiplex Real Time RT-PCR Assay for SARS-CoV-2 Detection

Coronavirus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in more than 386,000 deaths globally as of June 4, 2020. In this study, we developed a novel multiplex real time reverse transcription (RT)-PCR test for detection of SARS-CoV-2, with primers designed to amplify a 108 bp target on the spike surface glycoprotein (S gene) of SARS-CoV-2 and a hydrolysis Taqman probe designed to specifically detect SARS-CoV-2. Following our design, we evaluated the Limit of detection (LOD) and clinical performance of this laboratory-developed test (LDT). A LOD study with inactivated whole virus exhibited equal performance to that seen in the modified CDC assay with a final LOD of 1,301 ± 13 genome equivalents/ml for our assay vs 1,249 ± 14 genome equivalents/ml for the modified CDC assay. In addition, a clinical evaluation with 270 nasopharyngeal (NP) swab specimens exhibited 98.5% positive percent agreement and 99.3% negative percent agreement with the modified CDC assay. The multiplex design of this assay allows the testing of 91 patients per plate, versus a maximum of 29 patients per plate on the modified CDC assay, providing the benefit of testing significantly more patients per run and saving reagents during a time when both of these parameters have been critical. Our results demonstrate that our multiplex assay performs as well as the modified CDC assay, but is more efficient and cost effective and is therefore adequate for use as a diagnostic assay and for epidemiological surveillance and clinical management of SARS-CoV-2.View Full Text

pathology↗

bioRxiv2020

Analytical and Clinical Comparison of Three Nucleic Acid Amplification Tests for SARS-CoV-2 Detection

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) was first identified in December 2019 and has quickly become a worldwide pandemic. In response, many diagnostic manufacturers have developed molecular assays for SARS-CoV-2 under the Food and Drug Administration (FDA) Emergency Use Authorization (EUA) pathway. This study compared three of these assays: the Hologic Panther Fusion SARS-CoV-2 assay (Fusion), the Hologic Aptima SARS-CoV-2 assay (Aptima) and the BioFire Diagnostics COVID-19 test (BioFire), to determine analytical and clinical performance, as well as workflow. All three assays showed a similar limit of detection (LOD) using inactivated virus, with 100% detection ranging from 500-1,000 genome equivalents/ml, whereas use of a quantified RNA transcript standard showed the same trend, but had values ranging from 62.5 to 125 copies/ml, confirming variability in absolute quantification of reference standards. The clinical correlation found that the Fusion and BioFire assays had a positive percent agreement (PPA) of 98.7%, followed by the Aptima assay at 94.7% when compared to the consensus result. All three assays exhibited 100% negative percent agreement (NPA). Analysis of discordant results revealed that all four samples missed by the Aptima assay had Ct values >37 on the Fusion assay. In conclusion, while all three assays showed similar relative LODs, we showed differences in absolute LODs depending on which standard was employed. In addition, the Fusion and BioFire assays showed better clinical performance, while the Aptima assay showed a modest decrease in overall PPA. These findings should be kept in mind when making platform testing decisions.

microbiology↗

bioRxiv2020

The Pathogenicity of 2019 Novel Coronavirus in hACE2 Transgenic Mice

Severe acute respiratory syndrome CoV-2 (SARS-CoV-2) caused the Corona Virus Disease 2019 (COVID-19) cases in China has become a public health emergency of international concern (PHEIC). Based on angiotensin converting enzyme 2 (ACE2) as cell entry receptor of SARS-CoV, we used the hACE2 transgenic mice infected with SARS-CoV-2 to study the pathogenicity of the virus. Weight loss and virus replication in lung were observed in hACE2 mice infected with SARS-CoV-2. The typical histopathology was interstitial pneumonia with infiltration of significant lymphocytes and monocytes in alveolar interstitium, and accumulation of macrophages in alveolar cavities. Viral antigens were observed in the bronchial epithelial cells, alveolar macrophages and alveolar epithelia. The phenomenon was not found in wild type mice with SARS-CoV-2 infection. The pathogenicity of SARS-CoV-2 in hACE2 mice was clarified and the Kochs postulates were fulfilled as well, and the mouse model may facilitate the development of therapeutics and vaccines against SARS-CoV-2.

microbiology↗