scholarly journals Development of a Novel, Genome Subtraction-Derived, SARS-CoV-2-Specific COVID-19-nsp2 Real-Time RT-PCR Assay and Its Evaluation Using Clinical Specimens

2020 ◽  
Vol 21 (7) ◽  
pp. 2574 ◽  
Author(s):  
Cyril Chik-Yan Yip ◽  
Chi-Chun Ho ◽  
Jasper Fuk-Woo Chan ◽  
Kelvin Kai-Wang To ◽  
Helen Shuk-Ying Chan ◽  
...  

The pandemic novel coronavirus infection, Coronavirus Disease 2019 (COVID-19), has affected at least 190 countries or territories, with 465,915 confirmed cases and 21,031 deaths. In a containment-based strategy, rapid, sensitive and specific testing is important in epidemiological control and clinical management. Using 96 SARS-CoV-2 and 104 non-SARS-CoV-2 coronavirus genomes and our in-house program, GolayMetaMiner, four specific regions longer than 50 nucleotides in the SARS-CoV-2 genome were identified. Primers were designed to target the longest and previously untargeted nsp2 region and optimized as a probe-free real-time reverse transcription-polymerase chain reaction (RT-PCR) assay. The new COVID-19-nsp2 assay had a limit of detection (LOD) of 1.8 TCID50/mL and did not amplify other human-pathogenic coronaviruses and respiratory viruses. Assay reproducibility in terms of cycle threshold (Cp) values was satisfactory, with the total imprecision (% CV) values well below 5%. Evaluation of the new assay using 59 clinical specimens from 14 confirmed cases showed 100% concordance with our previously developed COVID-19-RdRp/Hel reference assay. A rapid, sensitive, SARS-CoV-2-specific real-time RT-PCR assay, COVID-19-nsp2, was developed.

2003 ◽  
Vol 112 (3) ◽  
pp. 252-257 ◽  
Author(s):  
Toshio Ishibashi ◽  
Hiroko Monobe ◽  
Masanobu Shinogami ◽  
Yuka Nomura ◽  
Jun Yano

Because respiratory viruses play an important role in the causation and pathogenesis of acute otitis media (AOM), determining which virus has infected a child is important with respect to vaccines and antiviral drugs. In some instances, this information might be used to prevent the occurrence of AOM. We used a rapid, economical, and sensitive diagnostic system involving a multiplex nested reverse transcription–polymerase chain reaction (RT-PCR) assay to detect various respiratory viruses in clinical specimens of middle ear fluid (MEF) from children with AOM in our hospital. Multiplex RT-PCR was completed on 40 MEF samples from 28 infants and children less than 6 years old with AOM. Viral RNA was detected in 17 MEF samples (43%). Respiratory syncytial virus type A was present in 12 samples, adenovirus in 3, rhinovirus in 2, and influenza A (H3N2) in 1. The multiplex RT-PCR assay is recommended to clinical laboratories that are considering adoption of a molecular technique for viral diagnosis.


2006 ◽  
Vol 89 (5) ◽  
pp. 1335-1340
Author(s):  
Amir Abdulmawjood ◽  
Holger Schnenbrcher ◽  
Michael BÜlte

Abstract A collaborative trial was conducted to evaluate a real-time reverse transcriptase-polymerase chain reaction (RT-PCR) assay for detection of central nervous system (CNS) tissues in meat products (e.g., sausages). The method is based on the detection of ruminant glial fibrillary acidic protein (GFAP) mRNA by applying real-time RT-PCR. The assay was evaluated through a multicenter trial involving 12 participating laboratories that received coded cDNA obtained from 3 different types of sausages. The participants used 5 different real-time detection systems. The results obtained in this validation revealed that this real-time RT-PCR assay performed well in the different laboratories with a detection limit of at least 0.1% CNS in those test materials that contained strongly heat-treated samples (sausages cooked at 120C) and the medium heat-treated samples (sausages cooked at 80C). The detection limit of liver sausages was determined to be 0.2% of CNS. Neither the samples with no CNS additive nor the bovine DNA and the negative control containing 100% swine brain gave any positive signals. The presented results indicate that the real-time RT-PCR assay was just as reproducible between laboratories, as repeatable within a laboratory, could reliably be used for detection of bovine spongiform encephalopathy risk material in meat and meat products, and signify that it may be used with confidence in any laboratory.


2004 ◽  
Vol 72 (3) ◽  
pp. 496-501 ◽  
Author(s):  
Xiaoli L. Pang ◽  
Bonita Lee ◽  
Nasim Boroumand ◽  
Barbara Leblanc ◽  
Jutta K. Preiksaitis ◽  
...  

2021 ◽  
Author(s):  
Emmanuel Oladipo Babafemi

Abstract Background: COVID-19 has spread globally since its discovery in Hubei province, China in December 2019 and became pandemic in 2020. COVID-19 is a new betacoronavirus and a variant of severe acute respiratory syndrome coronavirus 2 (SARA- CoV-2). Rapid, accurate and reliable diagnosis of COVID-19 will prevent the spread and allow for appropriate management. The main objective of this systematic review is to identify, appraise and summarise the published evidence on the diagnostic performance and effectiveness of SARS-CoV-2 virus in the diagnosis of current or previous COVID-19 using real-time polymerase chain reaction (RT-PCR) assay in low-and middle-income countries (LMICs). Methods: We will search MEDLINE/PubMed, EMBASE, BIOSIS, LILACS, Cochrane Infectious Diseases Group Specialised Register (CIDG SR), Global Health, and CINAHL for published studies for the diagnosis of COVID-19 using real-time polymerase chain reaction assay in LMICs There will be no restriction regarding the language, date of publication, and publication status. We will include retrospective, cross-sectional and cohort observational studies will be included in the review. Selection of studies, data extraction and management, assessment of risk of bias, and quality of evidence will be performed by two independent reviewers (EB and BC). A third researcher (GM) will be consulted in case of discrepancies. Depending on the availability and quality of the data, a meta-analysis will be performed. Otherwise, findings will be qualitatively reported. Discussion: To our knowledge, this is the first systematic review and meta-analysis to assess the uptake of RT-PCR assay for SARS-CoV-2 detection from clinical samples in human in LMICs. This review will make available evidence on the uptake, accuracy, approach, and interpretation of results of this assay in the context of COVID-19 diagnosis which will meet an urgent need, considering the diagnostic challenges of RT-PCR assay for COVID-19 diagnosis in humans. Systematic review registration: PROSPERO CRD42021271894


2020 ◽  
Author(s):  
Abhijeet Singh ◽  
Ayush Gupta ◽  
Kamanashish Das

Abstract Background: The ongoing pandemic of novel coronavirus disease 2019 (COVID-19) has received worldwide attention by becoming a major global health threat. We encountered one case with COVID-19 and tuberculosis (TB) coinfection which has not been frequently reported. Case presentation: A 76 year old female presented with acute respiratory symptoms superimposed on chronic symptoms, suggestive to have pneumonia. Oropharyngeal throat swab sample for COVID-19 was positive as detected by real-time reverse-transcriptase–polymerase-chain-reaction (RT-PCR) assay. GeneXpert Ultra detected Mycobacterium tuberculosis complex with Rifampicin resistance indeterminate. Patient was treated with appropriate management. Conclusion: Clinicians should suspect coinfection with TB during ongoing pandemic of COVID-19 as therapeutic strategies need to be determined timely to improve outcome and prevent transmission in community.


2019 ◽  
Vol 152 (6) ◽  
pp. 799-807 ◽  
Author(s):  
Andrew P Norgan ◽  
Lynne M Sloan ◽  
Bobbi S Pritt

Abstract Objectives Pathogenic free-living amebae (FLAs) cause skin, ocular, and central nervous system (CNS) infections with significant morbidity and mortality. Diagnosis of FLA infections by pathologic examination of tissue sections can be aided using molecular assays. This study investigated the performance characteristics of a multiplex real-time polymerase chain reaction (PCR) assay (FLA-PCR) for detection and differentiation of FLAs in clinical specimens. Methods FLA-PCR was performed on 39 human specimens comprising one cutaneous, 14 corneal, and 24 CNS formalin-fixed, paraffin-embedded (FFPE) tissues with a histopathologic diagnosis of FLA infection and four CNS FFPE tissues with inflammation but no evidence of FLAs. In addition, clinical specificity and assay limit of detection were determined. Results FLA detection sensitivities ranged from 79% to 84% in FFPE tissues. No cross-reactivity was observed. Conclusions While sensitivity is limited, FLA-PCR assay may serve as a useful adjunct for detection or confirmation of FLA infections in FFPE tissues.


2020 ◽  
pp. 1-2
Author(s):  
Mittal S ◽  
Tomar R ◽  
Garg A

This study aimed to assess the isolation of novel coronavirus in tears and conjunctival secretions by reverse transcriptase polymerase chain reaction (RT-PCR) assay from novel coronavirus disease 2019 (COVID-19) patients presenting with keratoconjunctivitis.


2009 ◽  
Vol 21 (3) ◽  
pp. 321-330 ◽  
Author(s):  
Scott M. Reid ◽  
Katja Ebert ◽  
Katarzyna Bachanek-Bankowska ◽  
Carrie Batten ◽  
Anna Sanders ◽  
...  

Rapid and accurate diagnosis is essential for effective control of foot-and-mouth disease (FMD). The present report describes the practical steps undertaken to deploy a real-time reverse transcription polymerase chain reaction (real-time RT-PCR) to process the samples received during the outbreaks of FMD in the United Kingdom in 2007. Two independent real-time RT-PCR assays targeting different regions (5′UTR and 3D) of the FMD virus (FMDV) genome were used to confirm the presence of FMDV in clinical samples collected from the first infected premises. Once the FMDV strain responsible had been sequenced, a single real-time RT-PCR assay (3D) was selected to test a total of 3,216 samples, including material from all 8 infected premises. Using a 96-well automated system to prepare nucleic acid template, up to 84 samples could be processed within 5 hr of submission, and up to 269 samples were tested per working day. A conservative cut-off was used to designate positive samples, giving rise to an assay specificity of 99.9% or 100% for negative control material or samples collected from negative premises, respectively. For the first time, real-time RT-PCR results were used to recognize preclinical FMD in a cattle herd. Furthermore, during the later stages of the outbreaks, the real-time RT-PCR assay supported an active surveillance program within high-risk cattle herds. To the authors' knowledge, this is the first documented use of real-time RT-PCR as a principal laboratory diagnostic tool following introduction of FMD into a country that was FMD-free (without vaccination) and highlights the advantages of this assay to support control decisions during disease outbreaks.


2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 9553-9553
Author(s):  
J. Liu ◽  
K. Qu ◽  
C. Chai ◽  
H. Li ◽  
A. Sferruzza ◽  
...  

9553 Background: Synovial sarcoma is the most common non-rhabdomyosarcomatous soft tissue sarcoma in children and adolescents. A specific translocation, t(X;18), induces fusion of the SYT gene on chromosome 18 to an SSX gene on chromosome X. The resulting fusion gene consists of at least 2 subtypes with different breakpoints: SYT-SSX1(X;18)(p11.23;q11.2) and SYT-SSX2 (X;18)(p11.21;q11.2). Because t(X;18) transcripts occur in >90% of synovial sarcoma subtypes, this marker may be useful for diagnosis. We evaluated the accuracy of a multiplex real-time reverse transcription-polymerase chain reaction (RT-PCR) assay for detection of the primary SYT-SSX fusion transcript types in formalin-fixed, paraffin-embedded (FFPE) tissues and frozen tissues. Methods: 17 tumors (7 synovial sarcomas, 4 Ewing’s sarcomas, 5 rhabdomyosarcomas, 1 small round blue-cell tumor), 4 normal tissues, and 4 control samples were tested for SYT-SSX translocations using real-time RT-PCR. Results were compared to those obtained with gel electrophoresis detection of amplified transcripts; discrepant results were confirmed by sequencing. Results: Concordance between real time RT-PCR and gel electrophoresis was 100% (25/25) for internal control genes and SYT-SSX1, and 92% (23/25) for SYT-SSX2. Of the 2 samples with discordant SYT-SSX2 results, 1 was positive by real-time RT-PCR but not gel electrophoresis and 1 was positive by electrophoresis but not real-time RT-PCR; in both cases, DNA sequencing confirmed the real-time RT-PCR results. The minimum percentage of tumor to normal cells required for detection of SYT-SSX fusion transcripts by real-time RT-PCR was 6.25%. Conclusions: This real-time RT-PCR assay appears to provide greater accuracy than gel electrophoresis for identification of SYT-SSX translocation and fusion types. No significant financial relationships to disclose.


2020 ◽  
Author(s):  
Abhijeet Singh ◽  
Ayush Gupta ◽  
Kamanashish Das

Abstract The ongoing pandemic of novel coronavirus disease 2019 (COVID-19) has received worldwide attention by becoming a major global health threat. We encountered one case of COVID-19 and pulmonary tuberculosis (TB) coinfection which has not been frequently reported. A 76 year old female presented with acute respiratory symptoms superimposed on chronic symptoms, suggestive to have pneumonia. Oropharyngeal throat swab sample for COVID-19 was positive as detected by real-time reverse-transcriptase–polymerase-chain-reaction (RT-PCR) assay. GeneXpert Ultra detected Mycobacterium tuberculosis complex with Rifampicin resistance indeterminate. Patient was conservatively treated with appropriate management. Clinicians should suspect COVID-19 coinfection with pulmonary TB while treating during ongoing pandemic as therapeutic strategies need to be determined accordingly to improve outcome and prevent transmission in community.


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