scholarly journals Detection of SARS Coronavirus in Patients with Severe Acute Respiratory Syndrome by Conventional and Real-Time Quantitative Reverse Transcription-PCR Assays

2004 ◽  
Vol 50 (1) ◽  
pp. 67-72 ◽  
Author(s):  
Leo L M Poon ◽  
Kwok Hung Chan ◽  
On Kei Wong ◽  
Timothy K W Cheung ◽  
Iris Ng ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Real Time ◽  
N Gene ◽  
Clinical Samples ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Reverse Transcription Pcr ◽  
Copy Numbers ◽  
Stool Samples ◽  
Pcr Assays

Abstract Background: A novel coronavirus (CoV) was recently identified as the agent for severe acute respiratory syndrome (SARS). We compared the abilities of conventional and real-time reverse transcription-PCR (RT-PCR) assays to detect SARS CoV in clinical specimens. Methods: RNA samples isolated from nasopharyngeal aspirate (NPA; n = 170) and stool (n = 44) were reverse-transcribed and tested by our in-house conventional RT-PCR assay. We selected 98 NPA and 37 stool samples collected at different times after the onset of disease and tested them in a real-time quantitative RT-PCR specific for the open reading frame (ORF) 1b region of SARS CoV. Detection rates for the conventional and real-time quantitative RT-PCR assays were compared. To investigate the nature of viral RNA molecules in these clinical samples, we determined copy numbers of ORF 1b and nucleocapsid (N) gene sequences of SARS CoV. Results: The quantitative real-time RT-PCR assay was more sensitive than the conventional RT-PCR assay for detecting SARS CoV in samples collected early in the course of the disease. Real-time assays targeted at the ORF 1b region and the N gene revealed that copy numbers of ORF 1b and N gene sequences in clinical samples were similar. Conclusions: NPA and stool samples can be used for early diagnosis of SARS. The real-time quantitative RT-PCR assay for SARS CoV is potentially useful for early detection of SARS CoV. Our results suggest that genomic RNA is the predominant viral RNA species in clinical samples.

Investigations on the Frequency of Norovirus Contamination of Ready-to-Eat Food Items in Istanbul, Turkey, by Using Real-Time Reverse Transcription PCR

2011 ◽  
Vol 74 (5) ◽  
pp. 840-843 ◽  
Author(s):  
AYSUN YILMAZ ◽  
KAMIL BOSTAN ◽  
EDA ALTAN ◽  
KARLO MURATOGLU ◽  
NURI TURAN ◽  
...  
Keyword(s):  
Real Time ◽  
Reverse Transcription ◽  
Epidemiological Studies ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Food Items ◽  
Reverse Transcription Pcr ◽  
Significant Difference ◽  
Tomato Sample ◽  
Pcr Assays

Investigation of norovirus (NoV) contamination of food items is important because many outbreaks occur after consumption of contaminated shellfish, vegetables, fruits, and water. The frequency of NoV contamination in food items has not previously been investigated in Turkey. The aim of this study was to investigate the frequency of human NoV genogroups (G) I and II in ready-to-eat tomatoes, parsley, green onion, lettuce, mixed salads, and cracked wheat balls. RNA was extracted with the RNeasy Mini Kit, and a real-time reverse transcription (RT) PCR assay was performed using primers specific for NoV GI and GII. Among the 525 samples analyzed, NoV GII was detected in 1 green onion sample and 1 tomato sample by both SYBR Green and TaqMan real-time RT-PCR assays; no GI virus was detected. The Enterobactericaeae and Escherichia coli levels in the NoV-positive green onion were 6.56 and 1.28 log CFU/g, and those in the tomato were 5.55 and 1.30 log CFU/g, respectively. No significant difference in the bacterial levels was found between the NoV-positive and NoV-negative samples. This study is the first in which NoV GII was found in ready-to-eat food collected from Istanbul, Turkey; thus, these foods may be considered a risk to human health. Epidemiological studies and measures to prevent NoV infection should be considered.

scholarly journals SARS-CoV-2 N Gene G29195T Point Mutation May Affect Diagnostic Reverse Transcription-PCR Detection

2022 ◽  
Author(s):  
Karrie K. K. Ko ◽  
Nurdyana Binte Abdul Rahman ◽  
Shireen Yan Ling Tan ◽  
Kenneth X. L. Chan ◽  
Sui Sin Goh ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Large Scale ◽  
N Gene ◽  
Clinical Samples ◽  
Rt Pcr ◽  
Viral Genomes ◽  
Reverse Transcription Pcr ◽  
Pcr Assays ◽  
Diagnostic Detection ◽  
Complementary Binding

Accurate diagnostic detection of SARS-CoV-2 currently depends on the large-scale deployment of RT-PCR assays. SARS-CoV-2 RT-PCR assays target predetermined regions in the viral genomes by complementary binding of primers and probes to nucleic acid sequences in the clinical samples.

scholarly journals Reverse transcription-PCR using a Primer Set Targeting the 3D Region Detects Foot-and-Mouth Disease Virus with High Sensitivity

2018 ◽  
Author(s):  
Tatsuya Nishi ◽  
Toru Kanno ◽  
Nobuaki Shimada ◽  
Kazuki Morioka ◽  
Makoto Yamakawa ◽  
...  
Keyword(s):  
Reverse Transcription ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Clinical Samples ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Reverse Transcription Pcr ◽  
Mouth Disease Virus ◽  
Foot And Mouth ◽  
Pcr Assays

AbstractBecause foot-and-mouth disease (FMD) has the potential to spread extensively, methods used for its diagnosis must be rapid and accurate. Therefore, reverse transcription-PCR (RT-PCR) plays an important diagnostic role. Here we designed the primer set FM8/9 to amplify 644 bases of the conserved 3D region of all seven serotypes of FMD virus (FMDV). We compared the performance of RT-PCR assays using FM8/9 with that using the primer set 1F/R targeting the 5’-UTR described in the manual of the World Organization for Animal Health. The detection limits of the RT-PCR assays were determined for 14 strains representing all serotypes. Compared with the sensitivities of the RT-PCR assay using 1F/R, those using FM8/9 were 101-to 104-fold higher for eight strains. To assess the validity of the methods for analyzing clinical samples, sera and saliva samples from pigs and cows infected with FMDV were collected daily and analyzed using the two PCR assays. The FM8/9 assay detected FMDV from all infected pigs and cows for longer times compared with the 1F/R assay, therefore revealing higher sensitivity for the clinical samples. Our results suggest that the FM8/9 RT-PCR assay is highly sensitive and is therefore suitable for the diagnosis of FMD.

scholarly journals Development of TaqMan-based real-time RT-PCR assay based on N gene for the quantitative detection of feline morbillivirus

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Siti Tasnim Makhtar ◽  
Sheau Wei Tan ◽  
Nur Amalina Nasruddin ◽  
Nor Azlina Abdul Aziz ◽  
Abdul Rahman Omar ◽  
...  
Keyword(s):  
Real Time ◽  
Measles Virus ◽  
Clinical Sample ◽  
N Gene ◽  
Clinical Samples ◽  
Quantitative Detection ◽  
High Morbidity ◽  
Canine Distemper ◽  
Rt Pcr ◽  
Pcr Assay

Abstract Background Morbilliviruses are categorized under the family of Paramyxoviridae and have been associated with severe diseases, such as Peste des petits ruminants, canine distemper and measles with evidence of high morbidity and/or could cause major economic loss in production of livestock animals, such as goats and sheep. Feline morbillivirus (FeMV) is one of the members of Morbilliviruses that has been speculated to cause chronic kidney disease in cats even though a definite relationship is still unclear. To date, FeMV has been detected in several continents, such as Asia (Japan, China, Thailand, Malaysia), Europe (Italy, German, Turkey), Africa (South Africa), and South and North America (Brazil, Unites States). This study aims to develop a TaqMan real-time RT-PCR (qRT-PCR) assay targeting the N gene of FeMV in clinical samples to detect early phase of FeMV infection. Results A specific assay was developed, since no amplification was observed in viral strains from the same family of Paramyxoviridae, such as canine distemper virus (CDV), Newcastle disease virus (NDV), and measles virus (MeV), and other feline viruses, such as feline coronavirus (FCoV) and feline leukemia virus (FeLV). The lower detection limit of the assay was 1.74 × 104 copies/μL with Cq value of 34.32 ± 0.5 based on the cRNA copy number. The coefficient of variations (CV) values calculated for both intra- and inter-assay were low, ranging from 0.34–0.53% and 1.38–2.03%, respectively. In addition, the clinical sample evaluation using this assay showed a higher detection rate, with 25 (35.2%) clinical samples being FeMV-positive compared to 11 (15.5%) using conventional RT-PCR, proving a more sensitive assay compared to the conventional RT-PCR. Conclusions The TaqMan-based real-time RT-PCR assay targeting the N gene described in this study is more sensitive, specific, rapid, and reproducible compared to the conventional RT-PCR assay targeting the N gene, which could be used to detect early infection in cats.

scholarly journals A Multiallelic Molecular Beacon-Based Real-Time RT-PCR Assay for the Detection of SARS-CoV-2

Life ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1146
Author(s):  
Andreas C. Chrysostomou ◽  
Johana Hezka Rodosthenous ◽  
Cicek Topcu ◽  
Christina Papa ◽  
Antonia Aristokleous ◽  
...  
Keyword(s):  
Real Time ◽  
Molecular Beacon ◽  
Infectious Agent ◽  
Clinical Samples ◽  
Detection Accuracy ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Multiple Introductions ◽  
Detection Techniques ◽  
Reverse Transcription Pcr

Emerging infectious viruses have led to global advances in the development of specific and sensitive detection techniques. Viruses have an inherent potential to easily mutate, presenting major hurdles for diagnostics and requiring methods capable of detecting genetically diverse viral strains. One such infectious agent is severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which emerged in December 2019 and has resulted in the global coronavirus disease 2019 (COVID-19) pandemic. This study presents a real-time reverse transcription PCR (RT-PCR) detection assay for SARS-CoV-2, taking into account its intrinsic polymorphic nature that arises due to genetic drift and recombination, as well as the possibility of continuous and multiple introductions of genetically nonidentical strains into the human population. This advance was achieved by using mismatch-tolerant molecular beacons designed to specifically detect the SARS-CoV-2 S, E, M, and N genes. These were applied to create a simple and reproducible real-time RT-PCR assay, which was validated using external quality control panels (QCMD: CVOP20, WHO: SARS-CoV-2-EQAP-01) and clinical samples. This assay was designed for high target detection accuracy and specificity and can also be readily adapted for the detection of other emerging and rapidly mutating pathogens.

scholarly journals Development of Taqman-Based Real-Time RT-PCR Assay Based on N Gene for The Quantitative Detection of Feline Morbillivirus

2020 ◽  
Author(s):  
Siti Tasnim Makhtar ◽  
Sheau Wei Tan ◽  
Nur Amalina Nasruddin ◽  
Nor Azlina Abdul Aziz ◽  
Abdul Rahman Omar ◽  
...  
Keyword(s):  
Real Time ◽  
Measles Virus ◽  
Clinical Sample ◽  
Feline Leukemia Virus ◽  
N Gene ◽  
Clinical Samples ◽  
Quantitative Detection ◽  
Canine Distemper ◽  
Rt Pcr ◽  
Pcr Assay

Abstract Background: Feline morbillivirus (FeMV) is a member of genus Morbillivirus which has been associated with the chronic kidney disease in cats even though a definite relationship is still unclear. Morbilliviruses are associated with severe diseases such as Peste des petits ruminants, canine distemper and measles. FeMV has been detected in many countries including Malaysia. This study aims to develop a Taqman real-time RT-PCR (qRT-PCR) assay targeting the N gene of FeMV in clinical samples to detect early phase of FeMV infection.Results: A specific assay was developed since no amplification was observed in viral strains from the same Paramyxoviridae family, such as canine distemper virus (CDV), Newcastle disease virus (NDV) and measles virus (MeV), and other feline viruses, such as feline coronavirus (FCoV) and feline leukemia virus (FeLV). The lower detection limit of the assay was 1.74 x 104 copies/L with Cq value of 34.32 0.5 based on the cRNA copy number. The coefficient of variations (CV) values calculated for both intra- and inter-assay were low, ranging from 0.34% - 0.53% and 1.38% - 2.03%, respectively. Besides that, the clinical sample evaluation using this assay showed a higher detection rate, with 26 (37%) clinical samples being FeMV-positive compared to 11 (15.5%) using conventional RT-PCR, proving a more sensitive assay compared to the conventional RT-PCR.Conclusions: The Taqman-based real-time RT PCR assay targeting the N gene described here is more sensitive, specific, rapid and reproducible compared to the conventional RT-PCR assay targeting the N gene and it could be used to detect early infection in cats.

scholarly journals Detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its first variants in fourplex real-time quantitative reverse transcription-PCR assays

2022 ◽  
Vol 9 (1) ◽  
pp. 1-20
Author(s):  
Mathieu Durand ◽  
Philippe Thibault ◽  
Simon Lévesque ◽  
Ariane Brault ◽  
Alex Carignan ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Real Time ◽  
Internal Control ◽  
Reverse Transcription ◽  
Locked Nucleic Acid ◽  
Clinical Samples ◽  
Quantitative Detection ◽  
Respiratory Pathogens ◽  
Pcr Assay ◽  
Reverse Transcription Pcr

The early diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections is required to identify and isolate contagious patients to prevent further transmission of SARS-CoV-2. In this study, we present a multitarget real-time TaqMan reverse transcription PCR (rRT-PCR) assay for the quantitative detection of SARS-CoV-2 and some of its circulating variants harboring mutations that give the virus a selective advantage. Seven different primer-probe sets that included probes containing locked nucleic acid (LNA) nucleotides were designed to amplify specific wild-type and mutant sequences in Orf1ab, Envelope (E), Spike (S), and Nucleocapsid (N) genes. Furthermore, a newly developed primer-probe set targeted human β2-microglobulin (B2M) as a highly sensitive internal control for RT efficacy. All singleplex and fourplex assays detected £ 14 copies/reaction of quantified synthetic RNA transcripts, with a linear amplification range of nine logarithmic orders. Primer-probe sets for detection of SARS-CoV-2 exhibited no false-positive amplifications with other common respiratory pathogens, including human coronaviruses NL63, 229E, OC43, and HKU-1. Fourplex assays were evaluated using 160 clinical samples positive for SARS-CoV-2. Results showed that SARS-CoV-2 viral RNA was detected in all samples, including viral strains harboring mutations in the Spike coding sequence that became dominant in the pandemic. Given the emergence of SARS-CoV-2 variants and their rapid spread in some populations, fourplex rRT-PCR assay containing four primer-probe sets represents a reliable approach to allow quicker detection of circulating relevant variants in a single reaction.

scholarly journals Monitoring Shedding of Five Genotypes of RotaTeq Vaccine Viruses by Genotype-Specific Real-Time Reverse Transcription-PCR Assays

2018 ◽  
Vol 56 (6) ◽  
Author(s):  
Yuki Higashimoto ◽  
Masaru Ihira ◽  
Yu Miyazaki ◽  
Ayumi Kuboshiki ◽  
Sayaka Yoshinaga ◽  
...  
Keyword(s):  
Real Time ◽  
Reverse Transcription ◽  
Cross Reactivity ◽  
Rt Pcr ◽  
Fecal Shedding ◽  
Reverse Transcription Pcr ◽  
Coefficients Of Variation ◽  
Long Time ◽  
Stool Samples ◽  
Pcr Assays

ABSTRACTRotaTeq (RV5) is a widely used live attenuated pentavalent rotavirus (RV) vaccine. Although fecal shedding of RV vaccine strains persists for long time periods, it is unclear how each vaccine strain replicates in intestinal tissue and is excreted in stool. To examine this issue, we established RV5 genotype-specific real-time reverse transcription-PCR (RT-PCR) assays. Five real-time RT-PCR assays were designed for the VP7 gene in genotypes G1, G2, G3, G4, and G6. All assays exhibited excellent linearity, and the detection limit was 1 infectious unit (IU)/reaction for G2, G4, and G6 and 10 IUs/reaction for G1 and G3. No cross-reactivity was observed among G genotypes. The inter- and intra-assay coefficients of variation were less than 3%. The assays were used to examine 129 stool samples collected from eight infants who received RV5. In cases 1 and 2, who received three rounds of vaccination, RV shedding decreased gradually with the number of vaccinations. G1 and G6 shedding appeared to be predominant in comparison to shedding of the other genotypes. Patterns of fecal shedding of the five genotypes of vaccine viruses differed between the eight vaccine recipients. RV5 genotype-specific real-time RT-PCR assays will be useful to study the molecular biology of RV5 replication in infants and experimental animals.

Detection of a novel bunyavirus associated with fever, thrombocytopenia and leukopenia syndrome in Henan Province, China, using real-time reverse transcription PCR

2013 ◽  
Vol 62 (7) ◽  
pp. 1060-1064 ◽  
Author(s):  
Xueyong Huang ◽  
Licheng Liu ◽  
Yanhua Du ◽  
Hongxia Ma ◽  
Yujiao Mu ◽  
...  
Keyword(s):  
Real Time ◽  
Reverse Transcription ◽  
High Sensitivity ◽  
Cross Reactivity ◽  
Henan Province ◽  
Clinical Samples ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Serum Samples ◽  
Reverse Transcription Pcr

A novel bunyavirus associated with fever, thrombocytopenia and leukopenia syndrome (FTLS) was discovered in Henan Province, China. Here, we report the development of an assay for this novel bunyavirus based on real-time reverse transcription PCR (RT-PCR). The assay exhibited high sensitivity and specificity without cross-reactivity towards 13 other viruses that cause similar symptoms. To evaluate the performance of this assay in detecting clinical samples, we analysed 261 serum samples from patients in Henan Province between 2007 and 2010. Of these samples, 91.95 % were bunyavirus positive. Compared with serological assays, the real-time PCR assay was much more sensitive in identifying infected patients 1 to 7 days after the onset of symptoms.

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