1
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Boxman ILA, Molin R, Persson S, Juréus A, Jansen CCC, Sosef NP, Le Guyader SF, Ollivier J, Summa M, Hautaniemi M, Suffredini E, Di Pasquale S, Myrmel M, Khatri M, Jamnikar-Ciglenecki U, Kusar D, Moor D, Butticaz L, Lowther JA, Walker DI, Stapleton T, Simonsson M, Dirks RAM. An international inter-laboratory study to compare digital PCR with ISO standardized qPCR assays for the detection of norovirus GI and GII in oyster tissue. Food Microbiol 2024; 120:104478. [PMID: 38431324 DOI: 10.1016/j.fm.2024.104478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 01/10/2024] [Accepted: 01/10/2024] [Indexed: 03/05/2024]
Abstract
An optimized digital RT-PCR (RT-dPCR) assay for the detection of human norovirus GI and GII RNA was compared with ISO 15216-conform quantitative real-time RT-PCR (RT-qPCR) assays in an interlaboratory study (ILS) among eight laboratories. A duplex GI/GII RT-dPCR assay, based on the ISO 15216-oligonucleotides, was used on a Bio-Rad QX200 platform by six laboratories. Adapted assays for Qiagen Qiacuity or ThermoFisher QuantStudio 3D were used by one laboratory each. The ILS comprised quantification of norovirus RNA in the absence of matrix and in oyster tissue samples. On average, results of the RT-dPCR assays were very similar to those obtained by RT-qPCR assays. The coefficient of variation (CV%) of norovirus GI results was, however, much lower for RT-dPCR than for RT-qPCR in intra-laboratory replicates (eight runs) and between the eight laboratories. The CV% of norovirus GII results was in the same range for both detection formats. Had in-house prepared dsDNA standards been used, the CV% of norovirus GII could have been in favor of the RT-dPCR assay. The ratio between RT-dPCR and RT-qPCR results varied per laboratory, despite using the distributed RT-qPCR dsDNA standards. The study indicates that the RT-dPCR assay is likely to increase uniformity of quantitative results between laboratories.
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Affiliation(s)
- Ingeborg L A Boxman
- Wageningen Food Safety Research (WFSR), Wageningen University and Research, Wageningen, the Netherlands.
| | - Ramia Molin
- European Union Reference Laboratory for Foodborne Viruses, Swedish Food Agency, Uppsala, Sweden.
| | - Sofia Persson
- European Union Reference Laboratory for Foodborne Viruses, Swedish Food Agency, Uppsala, Sweden.
| | - Anna Juréus
- European Union Reference Laboratory for Foodborne Viruses, Swedish Food Agency, Uppsala, Sweden.
| | - Claudia C C Jansen
- Wageningen Food Safety Research (WFSR), Wageningen University and Research, Wageningen, the Netherlands.
| | - Nils P Sosef
- Wageningen Food Safety Research (WFSR), Wageningen University and Research, Wageningen, the Netherlands.
| | - Soizick F Le Guyader
- French Research Institute for Exploitation of the Sea (Ifremer) - Laboratoire de Santé, Environnement et Microbiologie, Nantes, France.
| | - Joanna Ollivier
- French Research Institute for Exploitation of the Sea (Ifremer) - Laboratoire de Santé, Environnement et Microbiologie, Nantes, France.
| | | | | | - Elisabetta Suffredini
- Istituto Superiore di Sanità, Department of Food Safety, Nutrition and Veterinary Public Health, Rome, Italy.
| | - Simona Di Pasquale
- Istituto Superiore di Sanità, Department of Food Safety, Nutrition and Veterinary Public Health, Rome, Italy.
| | - Mette Myrmel
- Norwegian University of Life Sciences (NMBU), Faculty of Veterinary Medicine, Virology Unit, Ås, Norway.
| | - Mamata Khatri
- Norwegian University of Life Sciences (NMBU), Faculty of Veterinary Medicine, Virology Unit, Ås, Norway.
| | - Urska Jamnikar-Ciglenecki
- University of Ljubljana Veterinary Faculty, Institute of Food Safety, Feed and Environment, Ljubljana, Slovenia.
| | - Darja Kusar
- University of Ljubljana Veterinary Faculty, Institute of Microbiology and Parasitology, Ljubljana, Slovenia.
| | - Dominik Moor
- Federal Institute of Metrology METAS, Biological Analysis and References Laboratory, Bern, Switzerland.
| | - Lisa Butticaz
- Federal Institute of Metrology METAS, Biological Analysis and References Laboratory, Bern, Switzerland.
| | - James A Lowther
- Centre for Environment, Fisheries and Aquaculture Science, Weymouth, United Kingdom.
| | - David I Walker
- Centre for Environment, Fisheries and Aquaculture Science, Weymouth, United Kingdom.
| | - Tina Stapleton
- Centre for Environment, Fisheries and Aquaculture Science, Weymouth, United Kingdom.
| | - Magnus Simonsson
- European Union Reference Laboratory for Foodborne Viruses, Swedish Food Agency, Uppsala, Sweden.
| | - René A M Dirks
- Wageningen Food Safety Research (WFSR), Wageningen University and Research, Wageningen, the Netherlands.
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2
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Armenta-Leyva B, Munguía-Ramírez B, Cheng TY, Ye F, Henao-Díaz A, Giménez-Lirola LG, Zimmerman J. Normalizing real-time PCR results in routine testing. J Vet Diagn Invest 2024; 36:78-85. [PMID: 37919959 PMCID: PMC10734596 DOI: 10.1177/10406387231206080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2023] Open
Abstract
Normalization, the process of controlling for normal variation in sampling and testing, can be achieved in real-time PCR assays by converting sample quantification cycles (Cqs) to "efficiency standardized Cqs" (ECqs). We calculated ECqs as E-ΔCq, where E is amplification efficiency and ΔCq is the difference between sample and reference standard Cqs. To apply this approach to a commercial porcine reproductive and respiratory syndrome virus (PRRSV) RT-qPCR assay, we created reference standards by rehydrating and then diluting (1 × 10-4) a PRRSV modified-live vaccine (PRRS MLV; Ingelvac) with serum or oral fluid (OF) to match the sample matrix to be tested. Sample ECqs were calculated using the mean E and reference standard Cq calculated from the 4 reference standards on each plate. Serum (n = 132) and OF (n = 130) samples were collected from each of 12 pigs vaccinated with a PRRSV MLV from -7 to 42 d post-vaccination, tested, and sample Cqs converted to ECqs. Mean plate Es were 1.75-2.6 for serum and 1.7-2.3 for OF. Mean plate reference standard Cqs were 29.1-31.3 for serum and 29.2-31.5 for OFs. Receiver operating characteristic analysis calculated the area under the curve for serum and OF sample ECqs as 0.999 (95% CI: 0.997, 1.000) and 0.947 (0.890, 1.000), respectively. For serum, diagnostic sensitivity and specificity of the commercial PRRSV RT-qPCR assay were estimated as 97.9% and 100% at an ECq cutoff ≥ 0.20, and for OF, 82.6% and 100%, respectively, at an ECq cutoff ≥ 0.45.
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Affiliation(s)
- Betsy Armenta-Leyva
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Lloyd Veterinary Medical Center, Iowa State University, Ames, IA, USA
| | - Berenice Munguía-Ramírez
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Lloyd Veterinary Medical Center, Iowa State University, Ames, IA, USA
| | - Ting-Yu Cheng
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, the Ohio State University, Columbus, OH, USA
| | - Fangshu Ye
- Department of Statistics, College of Liberal Arts and Sciences, Iowa State University, Ames, IA, USA
| | | | - Luis G. Giménez-Lirola
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Lloyd Veterinary Medical Center, Iowa State University, Ames, IA, USA
| | - Jeffrey Zimmerman
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Lloyd Veterinary Medical Center, Iowa State University, Ames, IA, USA
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3
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de la Cruz Barron M, Kneis D, Geissler M, Dumke R, Dalpke A, Berendonk TU. Evaluating the sensitivity of droplet digital PCR for the quantification of SARS-CoV-2 in wastewater. Front Public Health 2023; 11:1271594. [PMID: 38425410 PMCID: PMC10903512 DOI: 10.3389/fpubh.2023.1271594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 11/27/2023] [Indexed: 03/02/2024] Open
Abstract
Wastewater surveillance for SARS-CoV-2 has been demonstrated to be a valuable tool in monitoring community-level virus circulation and assessing new outbreaks. It may become a useful tool in the early detection and response to future pandemics, enabling public health authorities to implement timely interventions and mitigate the spread of infectious diseases with the fecal excretion of their agents. It also offers a chance for cost-effective surveillance. Reverse transcription-quantitative polymerase chain reaction (RTqPCR) is the most commonly used method for viral RNA detection in wastewater due to its sensitivity, reliability, and widespread availability. However, recent studies have indicated that reverse transcription droplet digital PCR (RTddPCR) has the potential to offer improved sensitivity and accuracy for quantifying SARS-CoV-2 RNA in wastewater samples. In this study, we compared the performance of RTqPCR and RTddPCR approaches for SARS-CoV-2 detection and quantification on wastewater samples collected during the third epidemic wave in Saxony, Germany, characterized by low-incidence infection periods. The determined limits of detection (LOD) and quantification (LOQ) were within the same order of magnitude, and no significant differences were observed between the PCR approaches with respect to the number of positive or quantifiable samples. Our results indicate that both RTqPCR and RTddPCR are highly sensitive methods for detecting SARS-CoV-2. Consequently, the actual gain in sensitivity associated with ddPCR lags behind theoretical expectations. Hence, the choice between the two PCR methods in further environmental surveillance programs is rather a matter of available resources and throughput requirements.
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Affiliation(s)
| | - David Kneis
- Institute of Hydrobiology, Technische Universität Dresden, Dresden, Germany
| | - Michael Geissler
- Institute of Medical Microbiology and Virology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Roger Dumke
- Institute of Medical Microbiology and Virology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Alexander Dalpke
- Institute of Medical Microbiology and Virology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- Department of Infectious Diseases, Medical Microbiology and Hygiene, University Heidelberg, Heidelberg, Germany
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4
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Aravind Kumar N, Aradhana S, Harleen, Vishnuraj MR. SARS-CoV-2 in digital era: Diagnostic techniques and importance of nucleic acid quantification with digital PCRs. Rev Med Virol 2023; 33:e2471. [PMID: 37529971 DOI: 10.1002/rmv.2471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 07/04/2023] [Accepted: 07/12/2023] [Indexed: 08/03/2023]
Abstract
Studies related to clinical diagnosis and research of SARS-CoV-2 are important in the current pandemic era. Although molecular biology has emphasised the importance of qualitative analysis, quantitative analysis with nucleic acids in relation to SARS-CoV-2 needs to be clearly emphasised, which can provide perspective for viral dynamic studies of SARS-CoV-2. In this regard, the requirement and utilization of digital PCR in COVID-19 research has substantially increased during the pandemic, necessitating the aggregation of its cardinal applications and future scopes. Hence, this meta-review comprehensively addresses and emphasises the importance of nucleic acid quantification of SARS-CoV-2 RNA with digital PCR (dPCR). Various quantitative techniques of clinical significance like immunological, proteomic and nucleic acid-based diagnosis and quantification, have been comparatively discussed. Furthermore, the core part of the article focusses on the working principle and advantages of digital PCR, along with its applications in COVID-19 research. Several important applications like viral load quantitation, environmental surveillance and assay validation have been extensively investigated and discussed. Certain key future scopes of clinical importance, like mortality prediction, viral/variant-symbiosis, and antiviral studies were also identified, suggesting several possible digital PCR applications in COVID-19 research.
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Affiliation(s)
- N Aravind Kumar
- Meat Species Identification Laboratory, ICAR - National Meat Research Institute, Hyderabad, Telangana, India
| | - S Aradhana
- Department of Biotechnology, School of Bio Sciences & Technology (SBST), Vellore Institute of Technology, Vellore, Tamil Nadu, India
| | - Harleen
- Department of Biotechnology, Indian Institute of Technology Hyderabad, Kandi, Telangana, India
| | - M R Vishnuraj
- Meat Species Identification Laboratory, ICAR - National Meat Research Institute, Hyderabad, Telangana, India
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5
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Wagner K, Fox P, Gordon E, Hahn W, Olsen K, Markham A, Buglewicz D, Selemenakis P, Lessard A, Goldstein D, Threatt A, Davis L, Miller-Dawson J, Stockett H, Sanders H, Rugh K, Turner H, Remias M, Williams M, Chavez J, Galindo G, Cialek C, Koch A, Fout A, Fosdick B, Broeckling B, Zabel MD. A multiplexed, paired-pooled droplet digital PCR assay for detection of SARS-CoV-2 in saliva. Sci Rep 2023; 13:3075. [PMID: 36813822 PMCID: PMC9944410 DOI: 10.1038/s41598-023-29858-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 02/11/2023] [Indexed: 02/24/2023] Open
Abstract
In response to the SARS-CoV-2 pandemic, we developed a multiplexed, paired-pool droplet digital PCR (MP4) screening assay. Key features of our assay are the use of minimally processed saliva, 8-sample paired pools, and reverse-transcription droplet digital PCR (RT-ddPCR) targeting the SARS-CoV-2 nucleocapsid gene. The limit of detection was determined to be 2 and 12 copies per µl for individual and pooled samples, respectively. Using the MP4 assay, we routinely processed over 1,000 samples a day with a 24-h turnaround time and over the course of 17 months, screened over 250,000 saliva samples. Modeling studies showed that the efficiency of 8-sample pools was reduced with increased viral prevalence and that this could be mitigated by using 4-sample pools. We also present a strategy for, and modeling data supporting, the creation of a third paired pool as an additional strategy to employ under high viral prevalence.
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Affiliation(s)
- Kaitlyn Wagner
- Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, USA
- Colorado State University, Fort Collins, CO, 80523, USA
| | - Phil Fox
- Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, USA
- Colorado State University, Fort Collins, CO, 80523, USA
| | - Elizabeth Gordon
- Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, USA
- Colorado State University, Fort Collins, CO, 80523, USA
| | - Westen Hahn
- Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, USA
- Colorado State University, Fort Collins, CO, 80523, USA
| | - Kenzie Olsen
- Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, USA
- Colorado State University, Fort Collins, CO, 80523, USA
| | - Alex Markham
- Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, USA
- Colorado State University, Fort Collins, CO, 80523, USA
| | - Dylan Buglewicz
- Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, USA
- Colorado State University, Fort Collins, CO, 80523, USA
| | - Platon Selemenakis
- Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, USA
- Colorado State University, Fort Collins, CO, 80523, USA
| | - Avery Lessard
- Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, USA
- Colorado State University, Fort Collins, CO, 80523, USA
| | - Daniella Goldstein
- Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, USA
- Colorado State University, Fort Collins, CO, 80523, USA
| | - Alissa Threatt
- Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, USA
- Colorado State University, Fort Collins, CO, 80523, USA
| | - Luke Davis
- Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, USA
- Colorado State University, Fort Collins, CO, 80523, USA
| | - Jake Miller-Dawson
- Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, USA
- Colorado State University, Fort Collins, CO, 80523, USA
| | - Halie Stockett
- Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, USA
- Colorado State University, Fort Collins, CO, 80523, USA
| | | | - Kristin Rugh
- Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, USA
- Colorado State University, Fort Collins, CO, 80523, USA
| | - Houston Turner
- Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, USA
- Colorado State University, Fort Collins, CO, 80523, USA
| | - Michelle Remias
- Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, USA
- Colorado State University, Fort Collins, CO, 80523, USA
| | - Maggie Williams
- Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, USA
- Colorado State University, Fort Collins, CO, 80523, USA
| | - Jorge Chavez
- Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, USA
- Colorado State University, Fort Collins, CO, 80523, USA
| | - Gabriel Galindo
- Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, USA
- Colorado State University, Fort Collins, CO, 80523, USA
| | - Charlotte Cialek
- Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, USA
- Colorado State University, Fort Collins, CO, 80523, USA
| | - Amanda Koch
- Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, USA
- Colorado State University, Fort Collins, CO, 80523, USA
| | - Alex Fout
- Department of Statistics, Colorado State University, Fort Collins, CO, 80523, USA
- Colorado State University, Fort Collins, CO, 80523, USA
| | - Bailey Fosdick
- Colorado School of Public Health, University of Colorado Anschutz Medical Campus, Aurora, USA
| | - Bettina Broeckling
- Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, USA
- Colorado State University, Fort Collins, CO, 80523, USA
| | - Mark D Zabel
- Prion Research Center, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Fort Collins, USA.
- Colorado State University, Fort Collins, CO, 80523, USA.
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Marchini A, Petrillo M, Parrish A, Buttinger G, Tavazzi S, Querci M, Betsou F, Elsinga G, Medema G, Abdelrahman T, Gawlik B, Corbisier P. New RT-PCR Assay for the Detection of Current and Future SARS-CoV-2 Variants. Viruses 2023; 15:206. [PMID: 36680246 PMCID: PMC9863853 DOI: 10.3390/v15010206] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 12/05/2022] [Accepted: 01/04/2023] [Indexed: 01/13/2023] Open
Abstract
Multiple lineages of SARS-CoV-2 have been identified featuring distinct sets of genetic changes that confer to the virus higher transmissibility and ability to evade existing immunity. The continuous evolution of SARS-CoV-2 may pose challenges for current treatment options and diagnostic tools. In this study, we have first evaluated the performance of the 14 WHO-recommended real-time reverse transcription (RT)-PCR assays currently in use for the detection of SARS-CoV-2 and found that only one assay has reduced performance against Omicron. We then developed a new duplex real-time RT-PCR assay based on the amplification of two ultra-conserved elements present within the SARS-CoV-2 genome. The new duplex assay successfully detects all of the tested SARS-CoV-2 variants of concern (including Omicron sub-lineages BA.4 and BA.5) from both clinical and wastewater samples with high sensitivity and specificity. The assay also functions as a one-step droplet digital RT-PCR assay. This new assay, in addition to clinical testing, could be adopted in surveillance programs for the routine monitoring of SARS-CoV-2's presence in a population in wastewater samples. Positive results with our assay in conjunction with negative results from an Omicron-specific assay may provide timely indication of the emergence of a novel SARS-CoV-2 variant in a certain community and thereby aid public health interventions.
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Affiliation(s)
- Antonio Marchini
- European Commission, Joint Research Centre (JRC), 2440 Geel, Belgium
| | | | - Amy Parrish
- Department of Microbiology, Laboratoire National de Santé, 3583 Dudelange, Luxembourg
| | - Gerhard Buttinger
- European Commission, Joint Research Centre (JRC), 2440 Geel, Belgium
| | - Simona Tavazzi
- European Commission, Joint Research Centre (JRC), 21027 Ispra, Italy
| | - Maddalena Querci
- European Commission, Joint Research Centre (JRC), 21027 Ispra, Italy
| | - Fay Betsou
- Department of Microbiology, Laboratoire National de Santé, 3583 Dudelange, Luxembourg
- Biological Resource Center of Institut Pasteur, Université Paris Cité, 75015 Paris, France
| | - Goffe Elsinga
- KWR Water Research Institute, 3433 PE Nieuwegein, The Netherlands
| | - Gertjan Medema
- KWR Water Research Institute, 3433 PE Nieuwegein, The Netherlands
| | - Tamir Abdelrahman
- Department of Microbiology, Laboratoire National de Santé, 3583 Dudelange, Luxembourg
| | - Bernd Gawlik
- European Commission, Joint Research Centre (JRC), 21027 Ispra, Italy
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7
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Artika IM, Dewi YP, Nainggolan IM, Siregar JE, Antonjaya U. Real-Time Polymerase Chain Reaction: Current Techniques, Applications, and Role in COVID-19 Diagnosis. Genes (Basel) 2022; 13:genes13122387. [PMID: 36553654 PMCID: PMC9778061 DOI: 10.3390/genes13122387] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 12/01/2022] [Accepted: 12/07/2022] [Indexed: 12/23/2022] Open
Abstract
Successful detection of the first SARS-CoV-2 cases using the real-time polymerase chain reaction (real-time PCR) method reflects the power and usefulness of this technique. Real-time PCR is a variation of the PCR assay to allow monitoring of the PCR progress in actual time. PCR itself is a molecular process used to enzymatically synthesize copies in multiple amounts of a selected DNA region for various purposes. Real-time PCR is currently one of the most powerful molecular approaches and is widely used in biological sciences and medicine because it is quantitative, accurate, sensitive, and rapid. Current applications of real-time PCR include gene expression analysis, mutation detection, detection and quantification of pathogens, detection of genetically modified organisms, detection of allergens, monitoring of microbial degradation, species identification, and determination of parasite fitness. The technique has been used as a gold standard for COVID-19 diagnosis. Modifications of the standard real-time PCR methods have also been developed for particular applications. This review aims to provide an overview of the current applications of the real-time PCR technique, including its role in detecting emerging viruses such as SARS-CoV-2.
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Affiliation(s)
- I Made Artika
- Department of Biochemistry, Faculty of Mathematics and Natural Sciences, Bogor Agricultural University, Bogor 16680, Indonesia
- Eijkman Research Center for Molecular Biology, National Research and Innovation Agency, Bogor 16911, Indonesia
- Correspondence:
| | - Yora Permata Dewi
- Emerging Virus Research Unit, Eijkman Institute for Molecular Biology, Jalan Diponegoro 69, Jakarta 10430, Indonesia
| | - Ita Margaretha Nainggolan
- Eijkman Research Center for Molecular Biology, National Research and Innovation Agency, Bogor 16911, Indonesia
| | - Josephine Elizabeth Siregar
- Eijkman Research Center for Molecular Biology, National Research and Innovation Agency, Bogor 16911, Indonesia
| | - Ungke Antonjaya
- Eijkman Oxford Clinical Research Unit, Eijkman Institute for Molecular Biology, Jalan Diponegoro 69, Jakarta 10430, Indonesia
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8
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Hou Y, Chen S, Zheng Y, Zheng X, Lin JM. Droplet-based digital PCR (ddPCR) and its applications. Trends Analyt Chem 2022. [DOI: 10.1016/j.trac.2022.116897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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9
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Ahmed W, Smith WJM, Metcalfe S, Jackson G, Choi PM, Morrison M, Field D, Gyawali P, Bivins A, Bibby K, Simpson SL. Comparison of RT-qPCR and RT-dPCR Platforms for the Trace Detection of SARS-CoV-2 RNA in Wastewater. ACS ES&T WATER 2022; 2:1871-1880. [PMID: 36380768 PMCID: PMC8848507 DOI: 10.1021/acsestwater.1c00387] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
We compared reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and RT digital PCR (RT-dPCR) platforms for the trace detection of SARS-CoV-2 RNA in low-prevalence COVID-19 locations in Queensland, Australia, using CDC N1 and CDC N2 assays. The assay limit of detection (ALOD), PCR inhibition rates, and performance characteristics of each assay, along with the positivity rates with the RT-qPCR and RT-dPCR platforms, were evaluated by seeding known concentrations of exogenous SARS-CoV-2 in wastewater. The ALODs using RT-dPCR were approximately 2-5 times lower than those using RT-qPCR. During sample processing, the endogenous (n = 96) and exogenous (n = 24) SARS-CoV-2 wastewater samples were separated, and RNA was extracted from both wastewater eluates and pellets (solids). The RT-dPCR platform demonstrated a detection rate significantly greater than that of RT-qPCR for the CDC N1 and CDC N2 assays in the eluate (N1, p = 0.0029; N2, p = 0.0003) and pellet (N1, p = 0.0015; N2, p = 0.0067) samples. The positivity results also indicated that for the analysis of SARS-CoV-2 RNA in wastewater, including the eluate and pellet samples may further increase the detection sensitivity using RT-dPCR.
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Affiliation(s)
- Warish Ahmed
- CSIRO
Land and Water, Ecosciences Precinct, 41 Boggo Road, Dutton Park, QLD 4102, Australia
| | - Wendy J. M. Smith
- CSIRO
Land and Water, Ecosciences Precinct, 41 Boggo Road, Dutton Park, QLD 4102, Australia
| | - Suzanne Metcalfe
- CSIRO
Land and Water, Ecosciences Precinct, 41 Boggo Road, Dutton Park, QLD 4102, Australia
| | - Greg Jackson
- Water
Unit, Health Protection Branch, Prevention Division, Queensland Health, Brisbane, QLD 4001, Australia
| | - Phil M. Choi
- Water
Unit, Health Protection Branch, Prevention Division, Queensland Health, Brisbane, QLD 4001, Australia
| | - Mary Morrison
- Water
Unit, Health Protection Branch, Prevention Division, Queensland Health, Brisbane, QLD 4001, Australia
| | - Daniel Field
- Water
Unit, Health Protection Branch, Prevention Division, Queensland Health, Brisbane, QLD 4001, Australia
| | - Pradip Gyawali
- Institute
of Environmental Science and Research Ltd. (ESR), Porirua 5240, New Zealand
| | - Aaron Bivins
- Department
of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Kyle Bibby
- Department
of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana 46556, United States
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10
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Abstract
Monkeypox was declared a public health emergency of international concern by the World Health Organization (WHO) on 23 July 2022. Between 1 January and 23 July 2022, 16,016 laboratory confirmed cases of monkeypox and five deaths were reported to WHO from 75 countries on all continents. Public health authorities are proactively identifying cases and tracing their contacts to contain its spread. As with COVID-19, PCR is the only method capable of being deployed at sufficient speed to provide timely feedback on any public health interventions. However, at this point, there is little information on how those PCR assays are being standardised between laboratories. A likely reason is that testing is still limited on a global scale and that detection, not quantification, of monkeypox virus DNA is the main clinical requirement. Yet we should not be complacent about PCR performance. As testing requirements increase rapidly and specimens become more diverse, it would be prudent to ensure PCR accuracy from the outset to support harmonisation and ease regulatory conformance. Lessons from COVID-19 should aid implementation with appropriate material, documentary and methodological standards offering dynamic mechanisms to ensure testing that most accurately guides public health decisions.
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Affiliation(s)
- Jim F Huggett
- National Measurement Laboratory, LGC, Teddington, United Kingdom
- School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - David French
- National Measurement Laboratory, LGC, Teddington, United Kingdom
| | | | - Jacob Moran-Gilad
- Department of Health Policy and Management, School of Public Health, Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel
- Department of Clinical Microbiology and Infectious Diseases, Hadassah Medical Center, Jerusalem, Israel
| | - Alimuddin Zumla
- Centre for Clinical Microbiology, Division of Infection and Immunity, University College London, United Kingdom
- National Institutes of Health and Research Biomedical Research Centre, University College London Hospitals NHS Foundation Trust, London, United Kingdom
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11
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Abstract
The ongoing coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has led to a global public health disaster. The current gold standard for the diagnosis of infected patients is real-time reverse transcription-quantitative PCR (RT-qPCR). As effective as this method may be, it is subject to false-negative and -positive results, affecting its precision, especially for the detection of low viral loads in samples. In contrast, digital PCR (dPCR), the third generation of PCR, has been shown to be more effective than the gold standard, RT-qPCR, in detecting low viral loads in samples. In this review article, we selected publications to show the broad-spectrum applications of dPCR, including the development of assays and reference standards, environmental monitoring, mutation detection, and clinical diagnosis of SARS-CoV-2, while comparing it analytically to the gold standard, RT-qPCR. In summary, it is evident that the specificity, sensitivity, reproducibility, and detection limits of RT-dPCR are generally unaffected by common factors that may affect RT-qPCR. As this is the first time that dPCR is being tested in an outbreak of such a magnitude, knowledge of its applications will help chart a course for future diagnosis and monitoring of infectious disease outbreaks.
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12
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Van Poelvoorde LAE, Gand M, Fraiture MA, De Keersmaecker SCJ, Verhaegen B, Van Hoorde K, Cay AB, Balmelle N, Herman P, Roosens N. Strategy to Develop and Evaluate a Multiplex RT-ddPCR in Response to SARS-CoV-2 Genomic Evolution. Curr Issues Mol Biol 2021; 43:1937-1949. [PMID: 34889894 PMCID: PMC8928932 DOI: 10.3390/cimb43030134] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 10/08/2021] [Accepted: 11/02/2021] [Indexed: 12/12/2022] Open
Abstract
The worldwide emergence and spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) since 2019 has highlighted the importance of rapid and reliable diagnostic testing to prevent and control the viral transmission. However, inaccurate results may occur due to false negatives (FN) caused by polymorphisms or point mutations related to the virus evolution and compromise the accuracy of the diagnostic tests. Therefore, PCR-based SARS-CoV-2 diagnostics should be evaluated and evolve together with the rapidly increasing number of new variants appearing around the world. However, even by using a large collection of samples, laboratories are not able to test a representative collection of samples that deals with the same level of diversity that is continuously evolving worldwide. In the present study, we proposed a methodology based on an in silico and in vitro analysis. First, we used all information offered by available whole-genome sequencing data for SARS-CoV-2 for the selection of the two PCR assays targeting two different regions in the genome, and to monitor the possible impact of virus evolution on the specificity of the primers and probes of the PCR assays during and after the development of the assays. Besides this first essential in silico evaluation, a minimal set of testing was proposed to generate experimental evidence on the method performance, such as specificity, sensitivity and applicability. Therefore, a duplex reverse-transcription droplet digital PCR (RT-ddPCR) method was evaluated in silico by using 154 489 whole-genome sequences of SARS-CoV-2 strains that were representative for the circulating strains around the world. The RT-ddPCR platform was selected as it presented several advantages to detect and quantify SARS-CoV-2 RNA in clinical samples and wastewater. Next, the assays were successfully experimentally evaluated for their sensitivity and specificity. A preliminary evaluation of the applicability of the developed method was performed using both clinical and wastewater samples.
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Affiliation(s)
- Laura A. E. Van Poelvoorde
- Transversal Activities in Applied Genomics, Sciensano, 1050 Brussels, Belgium; (L.A.E.V.P.); (M.G.); (M.-A.F.); (S.C.J.D.K.)
| | - Mathieu Gand
- Transversal Activities in Applied Genomics, Sciensano, 1050 Brussels, Belgium; (L.A.E.V.P.); (M.G.); (M.-A.F.); (S.C.J.D.K.)
| | - Marie-Alice Fraiture
- Transversal Activities in Applied Genomics, Sciensano, 1050 Brussels, Belgium; (L.A.E.V.P.); (M.G.); (M.-A.F.); (S.C.J.D.K.)
| | - Sigrid C. J. De Keersmaecker
- Transversal Activities in Applied Genomics, Sciensano, 1050 Brussels, Belgium; (L.A.E.V.P.); (M.G.); (M.-A.F.); (S.C.J.D.K.)
| | - Bavo Verhaegen
- Food Pathogens, Sciensano, 1050 Brussels, Belgium; (B.V.); (K.V.H.)
| | | | - Ann Brigitte Cay
- Enzootic, Vector-Borne and Bee Diseases, Sciensano, 1180 Brussels, Belgium; (A.B.C.); (N.B.)
| | - Nadège Balmelle
- Enzootic, Vector-Borne and Bee Diseases, Sciensano, 1180 Brussels, Belgium; (A.B.C.); (N.B.)
| | - Philippe Herman
- Expertise and Service Provision, Sciensano, 1050 Brussels, Belgium;
| | - Nancy Roosens
- Transversal Activities in Applied Genomics, Sciensano, 1050 Brussels, Belgium; (L.A.E.V.P.); (M.G.); (M.-A.F.); (S.C.J.D.K.)
- Correspondence:
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13
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Long S. SARS-CoV-2 Subgenomic RNAs: Characterization, Utility, and Perspectives. Viruses 2021; 13:v13101923. [PMID: 34696353 PMCID: PMC8539008 DOI: 10.3390/v13101923] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Revised: 09/12/2021] [Accepted: 09/16/2021] [Indexed: 12/11/2022] Open
Abstract
SARS-CoV-2, the etiologic agent at the root of the ongoing COVID-19 pandemic, harbors a large RNA genome from which a tiered ensemble of subgenomic RNAs (sgRNAs) is generated. Comprehensive definition and investigation of these RNA products are important for understanding SARS-CoV-2 pathogenesis. This review summarizes the recent progress on SARS-CoV-2 sgRNA identification, characterization, and application as a viral replication marker. The significance of these findings and potential future research areas of interest are discussed.
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Affiliation(s)
- Samuel Long
- Independent Researcher, Clarksburg, MD 20871, USA
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