Simple Nano-Luciferase-Based Assay for the Rapid and High-Throughput Detection of SARS-CoV-2 3C-Like Protease.

In this study, we described an easy-to-perform nano-luciferase (nLuc) sensor for the rapid detection of 3-chymotrypsin-like protease (3CLpro) encoded by SARS-CoV-2. The technology is based on the cleavage reaction of recombinant-nLuc via 3CLpro. The nLuc-based assay is a general, one-step method and is naturally specific in detection. The stability, sensitivity, detection range, and response time are fully characterized. The application of 3CLpro detection in artificial and human saliva as well as antiviral drug screening demonstrates that the method can quantify 3CLpro with high sensitivity in one step. With its unique features, the nLuc-based assay may find broad applications in the auxiliary diagnosis of SARS-CoV-2, as well as other types of coronavirus infection.

Aptamer/antibody sandwich method for digital detection of SARS-CoV2 nucleocapsid protein.

Nucleocapsid protein (N protein) is the most abundant protein in SARS-CoV2 and is highly conserved, and there are no homologous proteins in the human body, making it an ideal biomarker for the early diagnosis of SARS-CoV2. However, early detection of clinical specimens for SARS-CoV2 remains a challenge due to false-negative results with viral RNA and host antibodies based testing. In this manuscript, a microfluidic chip with femtoliter-sized wells was fabricated for the sensitive digital detection of N protein. Briefly, ß-galactosidase (ß-Gal)-linked antibody/N protein/aptamer immunocomplexes were formed on magnetic beads (MBs). Afterwards, the MBs and ß-Gal substrate fluorescein-di-ß-d-galactopyranoside (FDG) were injected into the chip together. Each well of the chip would only hold one MB as confined by the diameter of the wells. The MBs in the wells were sealed by fluorocarbon oil, which confines the fluorescent (FL) product generated from the reaction between ß-Gal and FDG in the individual femtoliter-sized well and creates a locally high concentration of the FL product. The FL images of the wells were acquired using a conventional inverted FL microscope. The number of FL wells with MBs (FL wells number) and the number of wells with MBs (MBs wells number) were counted, respectively. The percentage of FL wells was calculated by dividing (FL wells number) by (MBs wells number). The higher the percentage of FL wells, the higher the N protein concentration. The detection limit of this digital method for N protein was 33.28 pg/mL, which was 300 times lower than traditional double-antibody sandwich based enzyme-linked immunosorbent assay (ELISA).

Molecular detections of coronavirus: current and emerging methodologies.

INTRODUCTION: Seven coronavirus species have been identified that can infect humans. While human coronavirus infections had been historically associated with only mild respiratory symptoms similar to the common cold, three coronaviruses identified since 2003, Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV), Middle East Respiratory Syndrome Coronavirus (MERS-CoV), and SARS-CoV-2, cause life-threatening severe respiratory syndromes. The coronavirus disease 2019 (COVID-19) caused by the highly transmissible SARS-CoV-2 has triggered a worldwide health emergency. Due to the lack of effective drugs and vaccination, rapid and reliable detection is of vital importance to control coronavirus epidemics/pandemics. AREA COVERED: A literature search was performed in Pubmed covering the detections and diagnostics of SARS, MERS and SARS-CoV-2. This review summarized the current knowledge of established and emerging methods for coronavirus detection. The characteristics of different diagnostic approaches were described, and the strengths and weaknesses of each method were analyzed and compared. In addition, future trends in the field of coronavirus detection were also discussed. EXPERT OPINION: Nucleic acid-based RT-PCR is the current golden-standard of coronavirus detection, while immunoassays provide history of coronavirus infection besides diagnostic information. Integrated high-throughput system holds the great potential and is the trend of future detection and diagnosis of virus infection.

A critical COVID-19 patient managed with timely evaluation, early prone positioning ventilation, and a multi-pronged pharmacotherapy

There is not yet a standard drug regimen for the treatment of coronavirus disease 2019 (COVID-19) patients. Here, we summarize our experience and successful treatment plan with a critical COVID-19 patient who required mechanical ventilation (MV). A 56-year-old man presented with a fever, cough, and dyspnea. He had not been to a medium/high risk epidemic area in the past year and had no family history of a disease cluster. COVID-19 was suspected based on clinical symptoms and radiologically detected ground-glass lung changes in the context of a normal white blood cell count (WBCC) and lymphocyte fraction (L%). A diagnosis of COVID-19 was confirmed by nucleic acid testing. Initially, he was started on noninvasive ventilation (NIV). Because his respiratory distress worsened over the following 2 h, he was transitioned to mechanical ventilation (MV), placed in prone positioning 12 h/day, and given a multi-pronged pharmacotherapy regimen that included an antiviral cocktail (lopinavir/ritonavir plus α-interferon), an immunity enhancer (thymosin α1), an anti-coagulant to prevent thrombosis (heparin). He was given an antibiotic to treat an opportunistic nosocomial infection. The patient has recovered well. The regimen applied in this case of timely evaluation, early prone positioning with MV, and a multi-pronged pharmacotherapy may be an effective strategy for patients with critical COVID-19, particularly with respect to preventing life-threatening worsening of the illness. [ABSTRACT FROM AUTHOR] Copyright of European Journal of Inflammation (Sage Publications, Ltd.) is the property of Sage Publications, Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)