scholarly journals Performance evaluation of the BD SARS-CoV-2 reagents for the BD MAX™ system

2021 ◽  
Author(s):  
Karen Yanson ◽  
William LaViers ◽  
Lori Neely ◽  
Elizabeth Lockamy ◽  
Luis Carlos Castillo-Hernandez ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Clinical Study ◽  
Sensitivity And Specificity ◽  
Clinical Performance ◽  
Qpcr Assay ◽  
Analytical Sensitivity ◽  
Post Market ◽  
Analytical Sensitivities ◽  
High Analytical Sensitivity ◽  
Roche Cobas

Background The RT-qPCR assay for detecting SARS-CoV-2 virus is the favorable approach to test suspected COVID-19 cases. However, discordant results can occur when two or more assays are compared. Variability in analytical sensitivities between assays, among other factors, may account for these differences in reporting. Methods The limits of detection (LOD) for the BD SARS-CoV-2 Reagents for BD MAXTM System ('MAX SARS-CoV-2 assay'), the Biomerieux BioFire® Respiratory Panel 2.1 ('BioFire SARS-CoV-2 assay'), the Roche cobas SARS-CoV-2 assay ('cobas SARS-CoV-2 assay'), and the Hologic Aptima® SARS-CoV-2 assay Panther® ('Aptima SARS-CoV-2 assay') RT-qPCR systems were determined using a total of 84 contrived nasopharyngeal specimens with seven target levels for each comparator. The positive and negative percent agreement (PPA and NPA, respectively) for the MAX SARS-CoV-2 assay were compared to the Aptima SARS-CoV-2 assay in a post-market clinical study utilizing 708 paired nasopharyngeal specimens collected from suspected COVID-19 cases. Discordant results were further tested by the cobas and BioFire SARS-CoV-2 assays. Results The measured LOD for the MAX SARS-CoV-2 assay (251 copies/mL) was comparable to the cobas SARS-CoV-2 assay (298 copies/mL) and the BioFire SARS-CoV-2 assay (302 copies/mL); the Aptima SARS-CoV-2 assay had a LOD of 612 copies/mL. The MAX SARS-CoV-2 assay had a PPA of 100% (95%CI: [97.3%-100.0%]) and a NPA of 96.7% (95%CI: [94.9%-97.9%]) when compared to the Aptima SARS-CoV-2 assay. Conclusions The MAX SARS-CoV-2 assay exhibited a high analytical sensitivity and specificity for SARS-CoV-2 detection. The clinical performance of the MAX SARS-CoV-2 assay agreed with another sensitive EUA cleared assay.

scholarly journals Performance evaluation of the BD SARS-CoV-2 reagents for the BD MAX™ system

2021 ◽  
Author(s):  
Karen Yanson ◽  
William Laviers ◽  
Lori Neely ◽  
Elizabeth Lockamy ◽  
Luis Carlos Castillo-Hernandez ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Clinical Study ◽  
Nucleic Acid ◽  
Clinical Performance ◽  
Nucleic Acid Amplification ◽  
Standard Approach ◽  
Limits Of Detection ◽  
Percent Agreement ◽  
Post Market ◽  
Roche Cobas

Background Nucleic acid amplification testing (NAAT) for SARS-CoV-2 is the standard approach for confirming COVID-19 cases. This study compared results between two Emergency Use Authorization (EUA) NAATs, with two additional EUA NAATs utilized for discrepant testing. Methods The limits of detection (LOD) for the BD SARS-CoV-2 Reagents for BD MAX™ System (“MAX SARS-CoV-2 assay”), the Biomerieux BioFire® Respiratory Panel 2.1 (“BioFire SARS-CoV-2 assay”), the Roche cobas SARS-CoV-2 assay (“cobas SARS-CoV-2 assay”), and the Hologic Aptima® SARS-CoV-2 assay Panther® (“Aptima SARS-CoV-2 assay”) NAAT systems were determined using a total of 84 contrived nasopharyngeal specimens with seven target levels for each comparator. The positive and negative percent agreement (PPA and NPA, respectively) of the MAX SARS-CoV-2 assay, compared to the Aptima SARS-CoV-2 assay, was evaluated in a post-market clinical study utilizing 708 nasopharyngeal specimens collected from suspected COVID-19 cases. Discordant testing was achieved using cobas and BioFire SARS-CoV-2 NAATs. Results In this study, the measured LOD for the MAX SARS-CoV-2 assay (251 copies/mL; [95%CI: 186, 427]) was comparable to the cobas SARS-CoV-2 assay (298 copies/mL; [95%CI: 225, 509]) and the BioFire SARS-CoV-2 assay (302 copies/mL; [95%CI: 219, 565]); the Aptima SARS-CoV-2 assay had a LOD of 612 copies/mL; [95%CI: 474, 918]. The MAX SARS-CoV-2 assay had a PPA of 100% (95%CI: [97.3%-100.0%]) and a NPA of 96.7% (95%CI: [94.9%-97.9%]) when compared to the Aptima SARS-CoV-2 assay. Conclusions The clinical performance of the MAX SARS-CoV-2 assay agreed with another sensitive EUA assay.

scholarly journals Development of a Genus-Specific Brucella Real-Time PCR Assay Targeting the 16S-23S rDNA Internal Transcribed Spacer from Different Specimen Types

2020 ◽  
Vol 7 (4) ◽  
pp. 175
Author(s):  
Rejoice Nyarku ◽  
Ayesha Hassim ◽  
Annelize Jonker ◽  
Melvyn Quan
Keyword(s):  
Sensitivity And Specificity ◽  
Internal Transcribed Spacer ◽  
Bacterial Culture ◽  
Limit Of Detection ◽  
Quantitative Polymerase Chain Reaction ◽  
Surface Protein ◽  
Qpcr Assay ◽  
Rapid Screening ◽  
Analytical Sensitivity ◽  
Tissue Samples

The aim of this study was to develop a 16S-23S ribosomal deoxyribonucleic acid internal transcribed spacer (ITS) quantitative polymerase chain reaction (qPCR) assay for the early diagnosis and rapid screening of brucellosis. Blood, milk, and tissue samples were spiked with B. abortus biovar 1 (B01988-18 strain) to determine the analytical sensitivity and specificity of the assay. The 95% limit of detection of the ITS qPCR assay was highest in tissue, followed by blood, then milk, i.e., 0.48, 4.43, and 15.18 bacteria/PCR reaction, respectively. The diagnostic performance of the assay was compared to the Brucella cell surface protein (BCSP) 31 qPCR assay and bacterial culture. Out of 56 aborted foetal tissue samples from bovine, ovine, and caprine, 33% (19/56) were positive for Brucella spp. The sensitivity and specificity of the ITS qPCR assay was 87% and 95% respectively, compared to 92% and 89% for the BCSP31 qPCR assay and 47% and 55% for bacterial culture, respectively. The assay was efficient, sensitive, and specific, making it a valuable tool in the early detection of the Brucella pathogen.

scholarly journals Clinical Validation of Automated and Rapid mariPOC SARS-CoV-2 Antigen Test

2021 ◽  
Author(s):  
Juha M. Koskinen ◽  
Petri Antikainen ◽  
Kristina Hotakainen ◽  
Anu Haveri ◽  
Niina Ikonen ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Limit Of Detection ◽  
Clinical Performance ◽  
High Capacity ◽  
Nasopharyngeal Swab ◽  
Analytical Sensitivity ◽  
Clinical Sensitivity ◽  
Qrt Pcr ◽  
Antigen Tests ◽  
Novel Coronavirus

ABSTRACTNovel SARS coronavirus causing COVID-19 was recognized in late 2019. Diagnostics was quickly ramped up worldwide based on the detection of viral RNA. Based on the scientific knowledge for pre-existing coronaviruses, it was expected that the RNA of this novel coronavirus will be detected at significant rates from symptomatic and asymptomatic individuals due to existence of non-infectious RNA. To increase the efficacy of diagnostics, surveillance, screening and pandemic control, rapid methods, such as antigen tests, are needed for decentralized testing and to assess infectiousness. The objectives were to verify analytical sensitivity and specificity, and assess the clinical sensitivity, specificity and usability of a novel automated mariPOC SARS-CoV-2 test based on sophisticated optical laser technology detecting viral structure proteins. Analytical performance was verified using bacterial and viral preparations. Clinical performance of the test was evaluated against qRT-PCR in a retrospective study with nasopharyngeal swab specimens (N=211) collected from symptomatic patients suspected of acute SARS-CoV-2 infections. Sensitivity and specificity of the mariPOC test were 92.3% (12/13) and 100.0% (198/198), respectively. The test’s limit of detection was 22 PFU/test and it had no cross-reactions with the tested respiratory microbes. Our study shows that the mariPOC can detect infectious individuals already in 20 minutes while clinical sensitivity close to qRT-PCR is achieved in two hours or less. The test targets conserved epitopes of SARS-CoV-2 nucleoprotein, making it robust against strain variations. The new test is a promising and versatile tool for syndromic testing of symptomatic cases and for high capacity infection control screening.

scholarly journals Analytical validation of a real-time hydrolysis probe PCR assay for quantifying Plasmodium falciparum parasites in experimentally infected human adults

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Claire Y. T. Wang ◽  
Emma L. Ballard ◽  
Zuleima Pava ◽  
Louise Marquart ◽  
Jane Gaydon ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Plasmodium Falciparum ◽  
18S Rrna ◽  
Drug Efficacy ◽  
18S Rrna Gene ◽  
Molecular Techniques ◽  
Qpcr Assay ◽  
Rrna Gene ◽  
Analytical Sensitivity ◽  
Blood Samples

Abstract Background Volunteer infection studies have become a standard model for evaluating drug efficacy against Plasmodium infections. Molecular techniques such as qPCR are used in these studies due to their ability to provide robust and accurate estimates of parasitaemia at increased sensitivity compared to microscopy. The validity and reliability of assays need to be ensured when used to evaluate the efficacy of candidate drugs in clinical trials. Methods A previously described 18S rRNA gene qPCR assay for quantifying Plasmodium falciparum in blood samples was evaluated. Assay performance characteristics including analytical sensitivity, reportable range, precision, accuracy and specificity were assessed using experimental data and data compiled from phase 1 volunteer infection studies conducted between 2013 and 2019. Guidelines for validation of laboratory-developed molecular assays were followed. Results The reportable range was 1.50 to 6.50 log10 parasites/mL with a limit of detection of 2.045 log10 parasites/mL of whole blood based on a parasite diluted standard series over this range. The assay was highly reproducible with minimal intra-assay (SD = 0.456 quantification cycle (Cq) units [0.137 log10 parasites/mL] over 21 replicates) and inter-assay (SD = 0.604 Cq units [0.182 log10 parasites/mL] over 786 qPCR runs) variability. Through an external quality assurance program, the QIMR assay was shown to generate accurate results (quantitative bias + 0.019 log10 parasites/mL against nominal values). Specificity was 100% after assessing 164 parasite-free human blood samples. Conclusions The 18S rRNA gene qPCR assay is specific and highly reproducible and can provide reliable and accurate parasite quantification. The assay is considered fit for use in evaluating drug efficacy in malaria clinical trials.

scholarly journals Evaluation of the New BD Max GC Real-Time PCR Assay, Analytically and Clinically as a Supplementary Test for the BD ProbeTec GC Qx Amplified DNA Assay, for Molecular Detection of Neisseria gonorrhoeae

2015 ◽  
Vol 53 (12) ◽  
pp. 3935-3937 ◽  
Author(s):  
Daniel Golparian ◽  
Stina Boräng ◽  
Martin Sundqvist ◽  
Magnus Unemo
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Real Time ◽  
Sensitivity And Specificity ◽  
Real Time Pcr ◽  
Molecular Detection ◽  
Analytical Sensitivity ◽  
Pcr Assay ◽  
Content Type ◽  
Dna Assay ◽  
Supplementary Test

The new BD Max GC real-time PCR assay showed high clinical and analytical sensitivity and specificity. It can be an effective and accurate supplementary test for the BD ProbeTec GC Qx amplified DNA assay, which had suboptimal specificity, and might also be used for initial detection ofNeisseria gonorrhoeae.

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