scholarly journals Combined Immunomagnetic Separation-Molecular Beacon-Reverse Transcription-PCR Assay for Detection of Hepatitis A Virus from Environmental Samples

2004 ◽  
Vol 70 (7) ◽  
pp. 4371-4374 ◽  
Author(s):  
Khaled H. Abd El Galil ◽  
M. A. El Sokkary ◽  
S. M. Kheira ◽  
Andre M. Salazar ◽  
Marylynn V. Yates ◽  
...  
Keyword(s):  
Real Time ◽  
Reverse Transcription ◽  
Environmental Samples ◽  
Hepatitis A ◽  
Molecular Beacon ◽  
Hepatitis A Virus ◽  
Immunomagnetic Separation ◽  
Rt Pcr ◽  
Pcr Assay ◽  
The Real

ABSTRACT In this study, a molecular-beacon-based real-time reverse transcription (RT)-PCR assay was developed to detect the presence of hepatitis A virus (HAV) in environmental samples. A 125-bp, highly conserved 5′ noncoding region of HAV was targeted. The sensitivity of the real-time RT-PCR assay was tested with 10-fold dilutions of viral RNA, and a detection limit of 1 PFU was obtained. The specificity of the assay was demonstrated by testing with other environmental pathogens and indicator microorganisms, and only HAV was positively identified. When combined with immunomagnetic separation, the real-time RT-PCR assay successfully detected as few as 20 PFU in seeded groundwater samples. Because of its simplicity and specificity, this assay has broad applications for the rapid detection of HAV in contaminated foods or water.

scholarly journals Real-Time Nucleic Acid Sequence-Based Amplification Assay for Detection of Hepatitis A Virus

2005 ◽  
Vol 71 (11) ◽  
pp. 7113-7116 ◽  
Author(s):  
Khaled H. Abd El Galil ◽  
M. A. El Sokkary ◽  
S. M. Kheira ◽  
Andre M. Salazar ◽  
Marylynn V. Yates ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Real Time ◽  
Hepatitis A ◽  
Molecular Beacon ◽  
Hepatitis A Virus ◽  
Immunomagnetic Separation ◽  
Nucleic Acid Sequence ◽  
The Real ◽  
Nasba Assay ◽  
Environmental Pathogens

ABSTRACT A nucleic acid sequence-based amplification (NASBA) assay in combination with a molecular beacon was developed for the real-time detection and quantification of hepatitis A virus (HAV). A 202-bp, highly conserved 5′ noncoding region of HAV was targeted. The sensitivity of the real-time NASBA assay was tested with 10-fold dilutions of viral RNA, and a detection limit of 1 PFU was obtained. The specificity of the assay was demonstrated by testing with other environmental pathogens and indicator microorganisms, with only HAV positively identified. When combined with immunomagnetic separation, the NASBA assay successfully detected as few as 10 PFU from seeded lake water samples. Due to its isothermal nature, its speed, and its similar sensitivity compared to the real-time RT-PCR assay, this newly reported real-time NASBA method will have broad applications for the rapid detection of HAV in contaminated food or water.

scholarly journals Development, Evaluation, and Standardization of a Real-Time TaqMan Reverse Transcription-PCR Assay for Quantification of Hepatitis A Virus in Clinical and Shellfish Samples

2006 ◽  
Vol 72 (6) ◽  
pp. 3846-3855 ◽  
Author(s):  
M. Isabel Costafreda ◽  
Albert Bosch ◽  
Rosa M. Pint�
Keyword(s):  
Real Time ◽  
Reverse Transcription ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Accurate Estimation ◽  
Acid Extraction ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Reverse Transcription Pcr ◽  
Development Evaluation

ABSTRACT A standardized real-time reverse transcription-PCR (RT-PCR) assay has been developed for an accurate estimation of the number of genome copies of hepatitis A virus (HAV) in clinical and shellfish samples. Real-time procedures were based on the amplification of a fragment of the highly conserved 5′ noncoding region and detection through an internal fluorescent probe, including TaqMan and beacon chemistries, in one- and two-step RT-PCR formats. The best performance in terms of sensitivity and reproducibility was achieved by a one-step TaqMan RT-PCR, with a sensitivity enabling the detection of 0.05 infectious unit and 10 copies of a single-stranded RNA (ssRNA) synthetic transcript. Standard reagents, such as a mengovirus strain and an ssRNA transcript, were employed as controls of nucleic acid extraction and RT-PCR, respectively. The test proved to be highly specific after a broad panel of enteric viruses was tested. Sequence alignment of target regions of the primers and probe proved them to be adequate for the quantification of all HAV genotypes. In addition, a quasispecies analysis of the mutant spectrum indicated that these regions are not prone to variability, thus confirming their robustness.

scholarly journals Rapid and Quantitative Detection of Hepatitis A Virus from Green Onion and Strawberry Rinses by Use of Real-Time Reverse Transcription-PCR

2005 ◽  
Vol 71 (9) ◽  
pp. 5624-5626 ◽  
Author(s):  
X. C. Shan ◽  
P. Wolffs ◽  
M. W. Griffiths
Keyword(s):  
Real Time ◽  
Reverse Transcription ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Quantitative Detection ◽  
Pcr Assay ◽  
Reverse Transcription Pcr ◽  
Immunomagnetic Capture ◽  
Capture Method

ABSTRACT In this study, an immunomagnetic capture method and a real-time reverse transcription-PCR assay were used to quantify hepatitis A virus (HAV) in green onion and strawberry rinses. This combined protocol detected as low as 0.5 PFU HAV in produce rinses and concentrated HAV levels up to 20-fold.

scholarly journals New Subgenotyping and Consensus Real-Time Reverse Transcription-PCR Assays for Hepatitis A Outbreak Surveillance

2019 ◽  
Vol 57 (9) ◽  
Author(s):  
William S. Probert ◽  
Jill K. Hacker
Keyword(s):  
Real Time ◽  
Reverse Transcription ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Outbreak Detection ◽  
Molecular Diagnostic ◽  
Diagnostic Tools ◽  
Pcr Assay ◽  
Reverse Transcription Pcr ◽  
Laboratory Surveillance

ABSTRACTLaboratory surveillance plays an important role in the detection and control of hepatitis A outbreaks and requires the application of rapid and accurate molecular diagnostic tools for hepatitis A virus (HAV) RNA detection, subgenotype identification, and sequence-based genotyping. We describe the development and validation of a triplex real-time, reverse transcription-PCR (triplex rRT-PCR) assay for the identification and discrimination of HAV subgenotypes IA, IB, and IIIA and a singleplex rRT-PCR assay designed to detect all HAV genotypes infecting humans. Overall, the accuracy, sensitivity, and specificity of the new assays were >97% for serum and plasma specimens collected during unrelated outbreaks of HAV in California and Michigan compared to a nested RT-PCR genotyping assay and the ISO 15216-1 rRT-PCR method for HAV detection. The new assays will permit the rapid detection of HAV RNA and discrimination among subgenotypes IA, IB, and IIIA in serum and plasma specimens, which will strengthen public health surveillance efforts for HAV outbreak detection and response.

scholarly journals Development of a Reverse Transcription-PCR–DNA Enzyme Immunoassay for Detection of “Norwalk-Like” Viruses and Hepatitis A Virus in Stool and Shellfish

2001 ◽  
Vol 67 (2) ◽  
pp. 742-749 ◽  
Author(s):  
Kellogg J. Schwab ◽  
Frederick H. Neill ◽  
Françoise Le Guyader ◽  
Mary K. Estes ◽  
Robert L. Atmar
Keyword(s):  
Enzyme Immunoassay ◽  
Reverse Transcription ◽  
Environmental Samples ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Pcr Amplification ◽  
Rt Pcr ◽  
Reverse Transcription Pcr ◽  
Pcr Product ◽  
Dna Enzyme Immunoassay

ABSTRACT Outbreaks of food- and waterborne gastroenteritis are being increasingly reported throughout the world. The analysis of environmental samples by newer diagnostic techniques such as reverse transcription-PCR (RT-PCR) amplification of nucleic acid has begun to identify human enteric viruses (predominantly “Norwalk-like” viruses [NLVs]) as the cause of many of these outbreaks. To streamline NLV detection from environmental samples such as shellfish, we have developed an RT-PCR–oligoprobe amplification and detection method using several new procedures that enable confirmed RT-PCR amplification and product detection in 1 day. The new steps include replacing reverse transcriptase and Taq polymerase with rTth polymerase, a heat-stable enzyme that functions as both a reverse transcriptase and DNA polymerase, in a single-tube, single-buffer, elevated temperature reaction. An internal standard Norwalk virus (NV) RNA control is added to each RT-PCR to identify sample inhibition, and thermolabile uracil N-glycosylase is incorporated into the reaction to prevent PCR product carryover contamination. Finally, RT-PCR-generated amplicons are detected in microtiter wells using virus-specific biotinylated oligoprobes in an enzyme-linked immunosorbent assay-based format. The DNA enzyme immunoassay is based on the capture of PCR product by biotinylated probes fixed onto individual streptavidin-coated wells. Using this method, low levels of NV were detected in stool and both NLV and hepatitis A virus were detected in bivalve mollusks following bioaccumulation. The method also successfully detected NLV in oysters implicated in an outbreak of NLV gastroenteritis. This method dramatically decreases the time needed for analysis and is amenable to automation.

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.

Rapid and real-time detection of hepatitis A virus by reverse transcription loop-mediated isothermal amplification assay

2007 ◽  
Vol 145 (2) ◽  
pp. 162-168 ◽  
Author(s):  
Tetsuo Yoneyama ◽  
Tomoko Kiyohara ◽  
Noriko Shimasaki ◽  
Gen Kobayashi ◽  
Yoshinori Ota ◽  
...  
Keyword(s):  
Real Time ◽  
Reverse Transcription ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Isothermal Amplification ◽  
Loop Mediated Isothermal Amplification ◽  
Amplification Assay ◽  
Real Time Detection
Sign in / Sign up

Export Citation Format

Share Document