scholarly journals Highly sensitive and specific detection of the SARS-CoV-2 Delta variant by double-mismatch allele-specific PCR

2021 ◽  
Author(s):  
Jeremy A Garson ◽  
Samuel Badru ◽  
Eleanor L Parker ◽  
Richard S Tedder ◽  
Myra O McClure
Keyword(s):  
Influenza A ◽  
Gene Mutations ◽  
Clinical Samples ◽  
Rt Pcr ◽  
Screening Assay ◽  
Spike Gene ◽  
Specific Pcr ◽  
The World ◽  
Allele Specific ◽  
Syncytial Virus

The highly transmissible Delta variant of SARS-CoV-2 (B.1.617.2), first identified in India, is currently replacing pre-existing variants in Europe, the USA, and many other parts of the world. It is essential to monitor efficiently its spread to help guide public health policies. Genome sequencing is the gold standard for identification of Delta, but is time-consuming, expensive, and unavailable in many regions. We describe here a rapid and relatively inexpensive alternative to sequencing for specific identification of the Delta variant, by application of double-mismatch allele-specific RT-PCR (DMAS-RT-PCR). The technique exploits forward and reverse allele-specific primers, targeting two spike gene mutations, L452R and T478K, within the same amplicon. The discriminatory power of each primer is enhanced by the presence of an additional mismatch located at the fourth nucleotide from the 3' end. Amplicons are detected in real-time by means of a conventional fluorescently-labelled hydrolysis probe. Specificity was assessed by testing a range of well characterised cell culture-derived viral isolates and clinical samples, most of which had previously been fully sequenced. In all cases the results of viral genotyping by DMAS-RT-PCR were entirely concordant with the results of sequencing, and the assay was shown to discriminate reliably between the Delta variant and other variants of concern (Alpha, B.1.1.7 and Beta, B.1.351), and 'wild-type' SARS-CoV-2. Other respiratory viruses, including influenza A and respiratory syncytial virus, were non-reactive in the assay. The sensitivity of DMAS-RT-PCR matched that of the diagnostic SARS-CoV-2 RT-qPCR screening assay, which targets the E gene. Several samples that could not be sequenced due to insufficient virus could successfully be genotyped by DMAS-RT-PCR. The method we describe would be simple to establish in any laboratory that has the ability to conduct PCR assays and should greatly facilitate monitoring of the spread of the Delta variant throughout the world, and its proportional representation in any SARS-CoV-2-infected population.

scholarly journals Multiplex PCR for Typing and Subtyping Influenza and Respiratory Syncytial Viruses

1998 ◽  
Vol 36 (10) ◽  
pp. 2990-2995 ◽  
Author(s):  
J. Stockton ◽  
J. S. Ellis ◽  
M. Saville ◽  
J. P. Clewley ◽  
M. C. Zambon
Keyword(s):  
Influenza A ◽  
Clinical Samples ◽  
Surveillance Program ◽  
Rt Pcr ◽  
Parainfluenza Viruses ◽  
Influenza A H1n1 ◽  
Pcr Method ◽  
Syncytial Virus ◽  
Primer Sets ◽  
Simplex Virus

A multiplex reverse transcription (RT)-PCR method that has been developed is capable of detecting and subtyping influenza A (H1N1 and H3N2) and B viruses as well as respiratory syncytial virus (RSV) types A and B in respiratory clinical samples taken as part of a national community-based surveillance program of influenza-like illness in England and Wales. The detection of each different pathogen depended on distinguishing five amplification products of different sizes on agarose gels following RT-PCR with multiple primer sets. The multiplex RT-PCR was tested with 65 nasopharyngeal apirates from which RSV had been isolated and 237 combined nose and throat swabs from which influenza A (H1N1 and H3N2) or B virus had been detected by virus isolation, as well as 40 respiratory samples from which other viruses including cytomegalovirus, herpes simplex virus, enteroviruses, and parainfluenza viruses had been grown. For the typing and subtyping of influenza A and B viruses and RSV types A and B, the multiplex RT-PCR gave an excellent (100%) correlation with the results of conventional typing and subtyping with specific antisera. Multiplex RT-PCR can also be used to accurately detect more than one viral template in the same reaction mixture, allowing viral coinfections to be identified with the same respiratory specimen.

scholarly journals Metagenomic Sequencing To Detect Respiratory Viruses in Persons under Investigation for COVID-19

2020 ◽  
Vol 59 (1) ◽  
pp. e02142-20
Author(s):  
Ahmed Babiker ◽  
Heath L. Bradley ◽  
Victoria D. Stittleburg ◽  
Jessica M. Ingersoll ◽  
Autum Key ◽  
...  
Keyword(s):  
Influenza A ◽  
Viral Infections ◽  
Respiratory Viruses ◽  
Human Metapneumovirus ◽  
Molecular Testing ◽  
Metagenomic Sequencing ◽  
Rt Pcr ◽  
Human Coronavirus ◽  
Testing Algorithms ◽  
Syncytial Virus

ABSTRACTBroad testing for respiratory viruses among persons under investigation (PUIs) for SARS-CoV-2 has been performed inconsistently, limiting our understanding of alternative viral infections and coinfections in these patients. RNA metagenomic next-generation sequencing (mNGS) offers an agnostic tool for the detection of both SARS-CoV-2 and other RNA respiratory viruses in PUIs. Here, we used RNA mNGS to assess the frequencies of alternative viral infections in SARS-CoV-2 RT-PCR-negative PUIs (n = 30) and viral coinfections in SARS-CoV-2 RT-PCR-positive PUIs (n = 45). mNGS identified all viruses detected by routine clinical testing (influenza A [n = 3], human metapneumovirus [n = 2], and human coronavirus OC43 [n = 2], and human coronavirus HKU1 [n = 1]). mNGS also identified both coinfections (1, 2.2%) and alternative viral infections (4, 13.3%) that were not detected by routine clinical workup (respiratory syncytial virus [n = 3], human metapneumovirus [n = 1], and human coronavirus NL63 [n = 1]). Among SARS-CoV-2 RT-PCR-positive PUIs, lower cycle threshold (CT) values correlated with greater SARS-CoV-2 read recovery by mNGS (R2, 0.65; P < 0.001). Our results suggest that current broad-spectrum molecular testing algorithms identify most respiratory viral infections among SARS-CoV-2 PUIs, when available and implemented consistently.

scholarly journals Simultaneous Detection and Identification of Human Parainfluenza Viruses 1, 2, and 3 from Clinical Samples by Multiplex PCR

1998 ◽  
Vol 36 (5) ◽  
pp. 1388-1391 ◽  
Author(s):  
Juan E. Echevarría ◽  
Dean D. Erdman ◽  
Ella M. Swierkosz ◽  
Brian P. Holloway ◽  
Larry J. Anderson
Keyword(s):  
Simultaneous Detection ◽  
Clinical Samples ◽  
Rt Pcr ◽  
Negative Results ◽  
Parainfluenza Viruses ◽  
Detection And Identification ◽  
Serotype 1 ◽  
Pcr Assays ◽  
Syncytial Virus ◽  
Human Parainfluenza Viruses

Reverse transcription (RT)-PCR assays have been widely described for use in the diagnosis of human parainfluenza viruses (HPIVs) and other respiratory virus pathogens. However, these assays are mostly monospecific, requiring separate amplifications for each HPIV type. In the present work, we describe multiplex RT-PCR assays that detect and differentiate HPIV serotypes 1, 2, and 3 in a combined reaction. Specifically, a mixture of three pairs of primers to conserved regions of the hemagglutinin-neuraminidase gene of each HPIV serotype was used for primary amplification, yielding amplicons with similar sizes. For typing, a second amplification was performed with a mixture of nested primers, yielding amplicons with sizes easily differentiated by agarose gel electrophoresis. A modified single-amplification RT-PCR assay with fluorescence-labeled nested primers, followed by analysis of the labeled products on an automated sequencing gel, was also evaluated. Fifteen temporally and geographically diverse HPIV isolates from the Centers for Disease Control and Prevention archives and 26 of 30 (87%) previously positive nasopharyngeal specimens (8 of 10 positive for HPIV serotype 1 [HPIV1], 9 of 10 positive for HPIV2, and 9 of 10 positive for HPIV3) were positive and were correctly typed by both assays. Negative results were obtained with naso- or oropharyngeal specimens and/or culture isolates of 33 unrelated respiratory tract pathogens, including HPIV4, enterovirus, rhinovirus, respiratory syncytial virus, adenovirus, influenza virus, and Streptococcus pneumoniae. Our multiplex RT-PCR assays provide sensitive, specific, and simplified tools for the rapid diagnosis of HPIV infections.

scholarly journals A Rapid and Consistent Method To Identify SARS-CoV-2 Variants By RT-PCR

2021 ◽  
Author(s):  
Marco Fabiani ◽  
Katia Margiotti ◽  
Manuela Sabatino ◽  
Antonella Viola ◽  
Alvaro Mesoraca ◽  
...  
Keyword(s):  
Defense Mechanisms ◽  
Immune Escape ◽  
Low Cost ◽  
Gene Mutations ◽  
Nucleotide Polymorphisms ◽  
Rt Pcr ◽  
Spike Gene ◽  
Natural Defense ◽  
The Uk ◽  
Next Generation Sequencing Ngs

Abstract Background Since 2020, the COVID-19 pandemic spread worldwide causing health, economic, and social distresses. Containment strategy relay on rapid and consistent methodology for molecular detection and characterization. The emerging variants of concern (VOCs) are currently associated with increased infectivity, and immune escape (natural defense mechanisms as well as a vaccine). Several VOCs has been detected and include lineage B.1.1.7 first identified in the UK, linage B.1.351 in South Africa, and lineage P.1 (B.1.1.28.1) in Brazil. Here we validated a rapid and low-cost technique to distinguish B.1.1.7, B.1.351 and P.1 SARS-CoV-2 variants by detecting Spike gene mutations using RT-PCR methodology. Results We recruited 77 positive patients affected by Coronavirus Disease-19 (COVID-19). Specific Real-time reverse transcription-polymerase chain reaction (RT-PCR) was employed targeting single nucleotide polymorphisms (SNPs) to screen Spike protein mutations. All data were validated by next generation sequencing (NGS) methodology and using sequence from a public database.Among 77 COVID-19 positive samples we could discriminate with 100% of concordance all the investigated SARS-CoV-2 variants when comparing with NGS method. Conclusions PCR-based assays for identification of circulating VOCs of SARS-CoV-2 resulted in a rapid method to identify the specific SARS-CoV-2 variants allowing a better survey of the spread of the virus and its transmissibility in the pandemic phase.

scholarly journals A quite sensitive fluorescent loop-mediated isothermal amplification for rapid detection of respiratory syncytial virus

2019 ◽  
Vol 13 (12) ◽  
pp. 1135-1141 ◽  
Author(s):  
Yihong Hu ◽  
Zhenzhou Wan ◽  
Yonglin Mu ◽  
Yi Zhou ◽  
Jia Liu ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Rapid Detection ◽  
Limit Of Detection ◽  
Isothermal Amplification ◽  
Clinical Samples ◽  
High Morbidity ◽  
Rt Pcr ◽  
Loop Mediated Isothermal Amplification ◽  
Syncytial Virus ◽  
Syto 9

Introduction: Human respiratory syncytial virus (hRSV) is a common respiratory virus closely related to respiratory tract infection (RTI). Rapid and accurate detection of hRSV is urgently needed to reduce the high morbidity and mortality due to hRSV infection. Methodology: Here, we established a highly sensitive and specific reverse-transcription loop-mediated isothermal amplification (RT-LAMP) assay for the rapid detection of A and B group hRSV simultaneously. The specific primer sets for hRSV A and B groups were designed in the M and M2-2 gene, respectively. SYTO 9 was used as the fluorescent dye for real-time monitoring of the amplification of hRSV RNA without cross reaction between hRSV A and B. Results: The limit of detection (LOD) of our new method was 281.17 50% tissue culture infective doses (TCID50)/mL for hRSV A and 1.58 TCID50/mL for hRSV B. Using 90 clinical samples, a comparison to traditional RT-PCR was performed to validate this assay. The positivity rate of RT-LAMP and RT-PCR were 67.8% and 55.6%, respectively, and the positivity rate of RT-LAMP was significantly higher than RT-PCR (χ2 test, P < 0.01). Conclusions: Compared with traditional RT-PCR method, the newly developed fluorescent RT-LAMP combined with well-designed primers and SYTO 9 is quite sensitive, specific, rapid and well applicable to hRSV clinical diagnosis.

scholarly journals Surveillance of SARS-CoV-2 lineage B.1.1.7 in Slovakia using a novel, multiplexed RT-qPCR assay

2021 ◽  
Author(s):  
Viera Kováčová ◽  
Kristína Boršová ◽  
Evan D Paul ◽  
Monika Radvánszka ◽  
Roman Hajdu ◽  
...  
Keyword(s):  
Vaccine Efficacy ◽  
Qpcr Assay ◽  
Clinical Samples ◽  
Modified Nucleotides ◽  
Clinical Sensitivity ◽  
Specific Pcr ◽  
High Prevalence ◽  
Surveillance Programs ◽  
Allele Specific ◽  
Allele Specific Pcr

AbstractBackgroundThe emergence of a novel SARS-CoV-2 variant of concern called B.1.1.7 lineage sparked global alarm due to evidence of increased transmissibility, mortality, and uncertainty about vaccine efficacy, thus accelerating efforts to detect and track the variant. Current approaches to detect lineage B.1.1.7 include sequencing and RT-qPCR tests containing a target assay that fails or results in reduced sensitivity towards the B.1.1.7 variant.AimSince many countries lack robust genomic surveillance programs and failed assays detect multiple unrelated variants containing similar mutations as B.1.1.7, we sought to develop an RT-qPCR test that can accurately and rapidly differentiate the B.1.1.7 variant from other SARS-CoV-2 variants.MethodsWe used bioinformatics, allele-specific PCR, and judicious placement of LNA-modified nucleotides to develop a test that differentiates B.1.1.7 from other SARS-CoV-2 variants. We validated the test on 106 clinical samples with lineage status confirmed by sequencing and conducted a surveillance study of B.1.1.7 lineage prevalence in Slovakia.ResultsOur multiplexed RT-qPCR test showed 97% clinical sensitivity at detecting lineage B.1.1.7. The assay was used in a country-wide surveillance of B.1.1.7 lineage spread in Slovakia. Retesting nearly 7,000 SARS-CoV-2 positive samples obtained during three campaigns performed within a one month period, revealed pervasive spread of B.1.1.7 with an average prevalence of 82%.ConclusionLabs can easily implement this test to rapidly scale B.1.1.7 surveillance efforts and it is particularly useful in countries with high prevalence of variants possessing only the ΔH69/ΔV70 deletion because current strategies using target failure assays incorrectly identify these as putative B.1.1.7 variants.

scholarly journals Rapid Identification of Nine Microorganisms Causing Acute Respiratory Tract Infections by Single-Tube Multiplex Reverse Transcription-PCR: Feasibility Study

1999 ◽  
Vol 37 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Britta Gröndahl ◽  
Wolfram Puppe ◽  
Andrea Hoppe ◽  
Inka Kühne ◽  
Josef A. I. Weigl ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Reverse Transcription ◽  
Influenza A ◽  
Respiratory Tract Infections ◽  
Clinical Samples ◽  
Rt Pcr ◽  
Reverse Transcription Pcr ◽  
Tract Infections ◽  
Type 3

Acute respiratory tract infections (ARIs) are leading causes of morbidity and, in developing countries, mortality in children. A multiplex reverse transcription-PCR (RT-PCR) assay was developed to allow in one test the detection of nine different microorganisms (enterovirus, influenza A and B viruses, respiratory syncytial virus [RSV], parainfluenzaviruses type 1 and type 3, adenovirus,Mycoplasma pneumoniae, and Chlamydia pneumoniae) that do not usually colonize the respiratory tracts of humans but, if present, must be assumed to be the cause of respiratory disease. Clinical samples from 1,118 children admitted to the Department of Pediatrics because of an ARI between November 1995 and April 1998 were used for a first clinical evaluation. Detection of one of the microorganisms included in the assay was achieved for 395 of 1,118 (35%) clinical samples, of which 37.5% were RSV, 20% were influenza A virus, 12.9% were adenovirus, 10.6% were enterovirus, 8.1% were M. pneumoniae, 4.3% were parainfluenzavirus type 3, 3.5% were parainfluenzavirus type 1, 2.8% were influenza B virus, and 0.2% were C. pneumoniae. Seasonal variations in the rates of detection of the different organisms were observed, as was expected from the literature. The levels of concordance with the data obtained by commercially available enzyme immunoassays were 95% for RSV and 98% for influenza A. The results show that the multiplex RT-PCR–enzyme-linked immunosorbent assay is a useful and rapid diagnostic tool for the management of children with ARI. Studies of the overall benefit of this method with regard to the use of antibiotics, the use of diagnostic procedures including additional microbiological tests, and hospitalization rate and duration are warranted.

scholarly journals Comparison of a New Gold Immunochromatographic Assay for the Rapid Diagnosis of the Novel Influenza A (H7N9) Virus with Cell Culture and a Real-Time Reverse-Transcription PCR Assay

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Changzhong Jin ◽  
Nanping Wu ◽  
Xiaorong Peng ◽  
Hangping Yao ◽  
Xiangyun Lu ◽  
...  
Keyword(s):  
Reverse Transcription ◽  
Influenza A ◽  
High Specificity ◽  
High Viral Load ◽  
Immunochromatographic Assay ◽  
Clinical Samples ◽  
H7n9 Virus ◽  
Rt Pcr ◽  
Reverse Transcription Pcr ◽  
Viral Culture

We assessed a colloidal gold immunochromatographic assay (GICA) for rapid detection of influenza A (H7N9) and compared it with reverse-transcription-polymerase chain reaction (RT-PCR) and viral culture. Samples from 35 H7N9 infected patients were collected, including 45 throat swab samples, 56 sputum samples, and 39 feces samples. All samples were tested by GICA, viral culture, and RT-PCR. GICA specifically reacted with recombinant HA proteins, virus lysates, and clinical samples from H7 subtype viruses. Compared with RT-PCR, GICA demonstrated low sensitivity (33.33%) but high specificity (97.56%). The positive rate of GICA tests for samples collected in the period from 8 to 21 days after contact with poultry was much higher than those for samples collected before or after this period. Compared with viral culture, GICA showed sensitivity of 91.67% and specificity of 82.03%. Sputum specimens were more likely to test positive for H7N9 virus than samples from throat swabs and feces. The GICA-based H7 test is a reliable, rapid, and convenient method for the screening and diagnosis of influenza A (H7N9) disease, especially for the sputum specimens with high viral load. It may be helpful in managing H7N9 epidemics and preliminary diagnosis in early stages in resource-limited settings.

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