scholarly journals True Measles Cases Undetected by Reverse Transcription-PCR (RT-PCR): Effect of Genetic Variability on Assay Sensitivity Needs To Be Regularly Surveyed

2019 ◽  
Vol 57 (8) ◽  
Author(s):  
Julia Dina ◽  
Jordane Omnes ◽  
Christelle Vauloup-Fellous ◽  
Louis Collet ◽  
Justine Hamel ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Reverse Transcription ◽  
Rt Pcr ◽  
Assay Sensitivity ◽  
Reverse Transcription Pcr

scholarly journals Environmental Detection of Genogroup I, II, and IV Noroviruses by Using a Generic Real-Time Reverse Transcription-PCR Assay

2013 ◽  
Vol 79 (21) ◽  
pp. 6585-6592 ◽  
Author(s):  
Takayuki Miura ◽  
Sylvain Parnaudeau ◽  
Marco Grodzki ◽  
Satoshi Okabe ◽  
Robert L. Atmar ◽  
...  
Keyword(s):  
Real Time ◽  
Reverse Transcription ◽  
Environmental Samples ◽  
Sewage Sample ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Assay Sensitivity ◽  
Reverse Transcription Pcr ◽  
Specificity And Sensitivity ◽  
Samples Selection

ABSTRACTNorovirus is the most common agent implicated in food-borne outbreaks and is frequently detected in environmental samples. These viruses are highly diverse, and three genogroups (genogroup I [GI], GII, and GIV) infect humans. Being noncultivable viruses, real-time reverse transcription-PCR (RT-PCR) is the only sensitive method available for their detection in food or environmental samples. Selection of consensus sequences for the design of sensitive assays has been challenging due to sequence diversity and has led to the development of specific real-time RT-PCR assays for each genogroup. Thus, sample screening can require several replicates for amplification of each genogroup (without considering positive and negative controls or standard curves). This study reports the development of a generic assay that detects all three human norovirus genogroups on a qualitative basis using a one-step real-time RT-PCR assay. The generic assay achieved good specificity and sensitivity for all three genogroups, detected separately or in combination. At variance with multiplex assays, the choice of the same fluorescent dye for all three probes specific to each genogroup allows the levels of fluorescence to be added and may increase assay sensitivity when multiple strains from different genogroups are present. When it was applied to sewage sample extracts, this generic assay successfully detected norovirus in all samples found to be positive by the genogroup-specific RT-PCRs. The generic assay also identified all norovirus-positive samples among 157 archived nucleic acid shellfish extracts, including samples contaminated by all three genogroups.

Comet and cup genes in Drosophila spermatogenesis: the first demonstration of post-meiotic transcription

2008 ◽  
Vol 36 (3) ◽  
pp. 540-542 ◽  
Author(s):  
Carine Barreau ◽  
Elizabeth Benson ◽  
Helen White-Cooper
Keyword(s):  
In Situ Hybridization ◽  
Expression Pattern ◽  
Reverse Transcription ◽  
Protein Product ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Single Cyst ◽  
Reverse Transcription Pcr

Post-meiotic transcription is widespread in mammalian spermatogenesis, but is generally believed to be absent from Drosophila spermatogenesis. Genes required during meiosis, in early spermatids or later in spermiogenesis are typically transcribed in primary spermatocytes in Drosophila. Their mRNAs are then stored in the cytoplasm until the protein product is needed. Recently, using in situ hybridization, we identified 17 Drosophila genes, collectively named ‘comets’ and ‘cups’, whose mRNAs are most abundant in, and localize to the distal ends of, elongating spermatids. Using a single-cyst quantitative RT–PCR (reverse transcription–PCR) assay, we confirmed this unusual expression pattern and conclusively demonstrate the existence of post-meiotic transcription in Drosophila spermatids. We found that transcription of comets and cups occurs just before protamines can be detected in spermatid nuclei.

scholarly journals Verification and diagnostic evaluation of the RealStar® Middle East respiratory syndrome coronavirus (N gene) reverse transcription-PCR kit 1.0

2019 ◽  
Vol 14 (11) ◽  
pp. 941-948 ◽  
Author(s):  
Leonie-Sophie Hecht ◽  
Angeles Jurado-Jimenez ◽  
Markus Hess ◽  
Hussein El Halas ◽  
Gregor Bochenek ◽  
...  
Keyword(s):  
Middle East ◽  
Reverse Transcription ◽  
Diagnostic Procedure ◽  
Middle East Respiratory Syndrome ◽  
Diagnostic Evaluation ◽  
N Gene ◽  
Rt Pcr ◽  
Reverse Transcription Pcr ◽  
Confirmatory Assay ◽  
Pcr Targeting

Aim: We report the diagnostic evaluation of a confirmatory reverse transcription-PCR (RT-PCR) kit targeting the Middle East respiratory syndrome coronavirus (MERS-CoV) N gene. Material & methods: 33 patient samples from two collections sites in Riyadh, Saudi Arabia, which were pre-characterized via real-time RT-PCR targeting MERS-CoV orf1a and upE, and were tested using the MERS-CoV N gene, as a confirmatory assay. This diagnostic procedure follows a two-step diagnostics scheme, recommended by the WHO. Results: 18/33 samples tested positive, 11/33 tested negative for MERS-CoV RNA and 2/33 showed uncertain results. Conclusion: The results suggest, that the RealStar® MERS-CoV (N gene) RT-PCR kit 1.0 can be considered a suitable and reliable confirmatory assay in combination with the RealStar MERS-CoV RT-PCR kit 1.0 according to the diagnostic scheme recommended by WHO.

scholarly journals Detection of mRNA by Reverse Transcription-PCR as an Indicator of Viability in Escherichia coliCells

1998 ◽  
Vol 64 (4) ◽  
pp. 1313-1318 ◽  
Author(s):  
G. E. C. Sheridan ◽  
C. I. Masters ◽  
J. A. Shallcross ◽  
B. M. Mackey
Keyword(s):  
Reverse Transcription ◽  
Room Temperature ◽  
Cellular Viability ◽  
Ethanol Treatment ◽  
Rt Pcr ◽  
Promising Candidate ◽  
Mrna Targets ◽  
Reverse Transcription Pcr ◽  
Different Types ◽  
The Relationship

ABSTRACT The relationship between the detection of mRNA and cellular viability in Escherichia coli was investigated in cells killed by heat or ethanol. Reverse transcription-PCR (RT-PCR) methods were developed for detecting mRNA from rpoH,groEL, and tufA genes. mRNA from all three genes was detected immediately after the cells had been killed by heat or ethanol but gradually disappeared with time when dead cells were held at room temperature. In heat-killed cells, some mRNA targets became undetectable after 2 to 16 h, whereas after ethanol treatment, mRNA was still detected after 16 h. In contrast, 16S rRNA was detected by RT-PCR in all samples containing dead cells and did not disappear during a subsequent incubation of 16 h at room temperature. Of the different types of nucleic acid, mRNA is the most promising candidate for an indicator of viability in bacteria, but its persistence in dead cells depends on the inactivating treatment and subsequent holding conditions.

scholarly journals Quantification of Hepatitis A Virus in Shellfish by Competitive Reverse Transcription-PCR with Coextraction of Standard RNA

1999 ◽  
Vol 65 (1) ◽  
pp. 322-326 ◽  
Author(s):  
Charlotte Arnal ◽  
Virginie Ferre-Aubineau ◽  
Berangere Mignotte ◽  
Berthe Marie Imbert-Marcille ◽  
Sylviane Billaudel
Keyword(s):  
Tissue Culture ◽  
Reverse Transcription ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Internal Standard ◽  
Wild Type ◽  
Rt Pcr ◽  
Reverse Transcription Pcr ◽  
Reproducible Method ◽  
Dna Enzyme Immunoassay

ABSTRACT To quantify hepatitis A virus (HAV) in experimentally contaminated mussels, we developed an internal standard RNA with a 7-nucleotide deletion for competitive reverse transcription (RT)-PCR. Deposited directly into the sample, this standard was used both as extraction control and as quantification tool. After coextraction and competitive RT-PCR, standard and wild-type products were detected by differential hybridization with specific probes and a DNA enzyme immunoassay. The quantifiable range with this reproducible method was 104 to 107 copies of HAV/gram or 400 to 106 50% tissue culture infective doses/ml.

scholarly journals Evaluation of the PAX8/PPARG Translocation in Follicular Thyroid Cancer with a 4-Color Reverse-Transcription PCR Assay and Automated High-Resolution Fragment Analysis

2010 ◽  
Vol 56 (3) ◽  
pp. 391-398 ◽  
Author(s):  
Alicia Algeciras-Schimnich ◽  
Dragana Milosevic ◽  
Bryan McIver ◽  
Heather Flynn ◽  
Honey V Reddi ◽  
...  
Keyword(s):  
Thyroid Cancer ◽  
High Resolution ◽  
Reverse Transcription ◽  
Thyroid Tissue ◽  
Molecular Testing ◽  
Analytical Sensitivity ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Fragment Analysis ◽  
Reverse Transcription Pcr

Abstract Background: Molecular testing of thyroid malignancies, in combination with cytologic and histologic examination, is becoming increasingly attractive as a tool for refining traditional morphologic diagnosis. The molecular changes associated with follicular thyroid carcinoma (FTC) are point mutations in RAS oncogenes or the presence of PAX8/PPARG (paired box 8/peroxisome proliferator-activated receptor gamma) rearrangement. Methods: We developed and validated a clinical assay for the detection of PAX8/PPARG rearrangements that uses a 4-color reverse-transcription PCR (RT-PCR) assay and high-resolution fragment analysis. Results: The RT-PCR assay is applicable for detecting the various described fusion transcripts of PAX8/PPARG in formalin-fixed, paraffin-embedded thyroid tissue and in fine-needle aspirate biopsy washes from thyroid nodules. The analytical sensitivity of the assay is 1 abnormal cell in a background of 100–10 000 translocation-negative cells. A comparison of the RT-PCR assay with dual-fusion fluorescence in situ hybridization showed an overall concordance of 95%. With this assay, we obtained a prevalence for the PAX8/PPARG rearrangement in FTC of 62% (13 of 21 cases), compared with a 5% prevalence (3 of 55) for other follicular cell–derived neoplasms. Conclusions: The introduction of this assay into clinical practice could provide useful information for the diagnosis and possibly for the prognosis and treatment of thyroid cancer in the future.

scholarly journals Quantitative Reverse Transcription-PCR Assay with an Internal Standard for the Detection of Prostate-specific Antigen mRNA

1999 ◽  
Vol 45 (9) ◽  
pp. 1397-1407 ◽  
Author(s):  
Alice Ylikoski ◽  
Minna Sjöroos ◽  
Åke Lundwall ◽  
Matti Karp ◽  
Timo Lövgren ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Detection Limit ◽  
Prostate Specific Antigen ◽  
Reverse Transcription ◽  
Specific Antigen ◽  
Internal Standard ◽  
Quantitative Detection ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Reverse Transcription Pcr

Abstract Background: Circulating prostate cells can be detected with a reverse transcription-PCR (RT-PCR) assay for prostate-specific antigen (PSA) mRNA. We have developed a new quantitative RT-PCR method for measuring PSA mRNA. Methods: The method uses a PSA-like internal standard (IS) mRNA that is added into the sample at the beginning of the RNA extraction and coamplified by RT-PCR with the PSA in the sample. After PCR amplification, the IS and PSA products are selectively detected by hybridization in a microtitration plate using probes labeled with fluorescent europium chelates. Results: The method was validated with PSA and IS mRNAs and PSA-expressing cells to obtain a detection limit of 50 PSA mRNA copies (i.e., signal 2 times the mean of zero signal), linearity up to 106 copies, and detection of a single PSA-expressing cell. In preliminary evaluations, 60% (n = 10) of the prostate cancer patients with skeletal metastases gave results above the detection limit (500 PSA mRNA copies in 5 mL of blood). The total number of PSA copies ranged from 900 ± 200 to 44 100 ± 4900 (mean ± SD) in the samples, corresponding to ∼1–100 PSA-expressing cells in 5 mL of blood. In the controls (n = 34), none of the healthy females and 2 of 19 healthy males had detectable PSA mRNA [700 ± 100 and 2000 ± 900 (mean ± SD) PSA mRNA copies in 5 mL of blood for the 2 males]. Conclusions: The assay provides sensitive and quantitative detection of PSA mRNA expression from blood samples and can be used to establish the clinically significant number of PSA mRNA copies in prostate cancer.

scholarly journals Reference Human Rotavirus A Genome Sequence from a Previously Vaccinated Child with Diarrhea in Nigeria

2020 ◽  
Vol 9 (5) ◽  
Author(s):  
T. O. C. Faleye ◽  
U. E. George ◽  
C. Simsek ◽  
O. A. Arowolo ◽  
O. M. Adewumi ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Reverse Transcription ◽  
Rapid Test ◽  
Etiologic Agent ◽  
Rt Pcr ◽  
Rotavirus A ◽  
Reverse Transcription Pcr ◽  
Human Rotavirus ◽  
A Genome ◽  
Genotype Constellation

In 2018, a 26-month-old girl, fully vaccinated with Rotarix in 2016, presented with fever, diarrhea, and vomiting. A rapid test showed that her feces contained rotavirus A (RVA). VP7 reverse transcription-PCR (RT-PCR) and Illumina sequencing showed that a G1P[8] strain with a Wa-like genotype constellation was the etiologic agent. This is the first near-complete RVA genome sequence from Nigeria.

scholarly journals A Multiplex Reverse Transcription-PCR Method for Detection of Human Enteric Viruses in Groundwater

2003 ◽  
Vol 69 (6) ◽  
pp. 3158-3164 ◽  
Author(s):  
G. Shay Fout ◽  
Beth C. Martinson ◽  
Michael W. N. Moyer ◽  
Daniel R. Dahling
Keyword(s):  
Reverse Transcription ◽  
Hepatitis A Virus ◽  
Disease Outbreaks ◽  
Enteric Viruses ◽  
The United States ◽  
Norwalk Virus ◽  
Rt Pcr ◽  
Reverse Transcription Pcr ◽  
Groundwater Samples ◽  
Human Enteric Viruses

ABSTRACT Untreated groundwater is responsible for about half of the waterborne disease outbreaks in the United States. Human enteric viruses are thought to be leading etiological agents of many of these outbreaks, but there is relatively little information on the types and levels of viruses found in groundwater. To address this problem, monthly samples from 29 groundwater sites were analyzed for 1 year for enteroviruses, hepatitis A virus, Norwalk virus, reoviruses, and rotaviruses by multiplex reverse transcription-PCR (RT-PCR). A procedure with which to remove environmental RT-PCR inhibitors from groundwater samples was developed. The procedure allowed an average of 71 liters of the original groundwater to be assayed per RT-PCR, with an average virus recovery rate of 74%, based on seeded samples. Human enteric viruses were detected in 16% of the groundwater samples analyzed, with reoviruses being the most frequently detected virus group.

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