scholarly journals Nucleic Acid Detection of Major Foodborne Viral Pathogens Human: Noroviruses and Hepatitis A Virus

10.5772/62112 ◽  
2016 ◽  
Author(s):  
Haifeng Chen
Keyword(s):  
Nucleic Acid ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Nucleic Acid Detection ◽  
Viral Pathogens ◽  
Human Noroviruses

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 A Chemical-Enhanced System for CRISPR-Based Nucleic Acid Detection

2021 ◽  
Author(s):  
Zihan Li ◽  
Wenchang Zhao ◽  
Shixin Ma ◽  
Zexu Li ◽  
Yingjia Yao ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Detection System ◽  
Point Of Care ◽  
Detection Sensitivity ◽  
Nucleic Acid Detection ◽  
Chemical Additives ◽  
Lateral Flow Strip ◽  
Viral Pathogens ◽  
Detection Systems ◽  
System Robustness

The CRISPR-based nucleic acid detection systems such as SHERLOCK, DETECTR and HOLMES have shown great potential for point-of-care testing of viral pathogens, especially in the context of COVID-19 pandemic. Here we optimize several key parameters of reaction chemistry and develop a Chemical Enhanced CRISPR Detection system for nucleic acid (termed CECRID). For the Cas12a/Cas13a-based signal detection phase, we determine buffer conditions and substrate range for optimal detection performance. By comparing several chemical additives, we find that addition of L-proline can secure or enhance Cas12a/Cas13a detection capability. For isothermal amplification phase with typical LAMP and RPA methods, inclusion of L-proline can also enhance specific target amplification as determined by CRISPR detection. Using SARS-CoV-2 pseudovirus, we demonstrate CECRID has enhanced detection sensitivity over chemical additive-null method with either fluorescence or lateral flow strip readout. Thus, CECRID provides an improved detection power and system robustness towards practical application of CRISPR-based diagnostics.

scholarly journals cDNA clone of hepatitis A virus encoding a virulent virus: induction of viral hepatitis by direct nucleic acid transfection of marmosets.

1992 ◽  
Vol 66 (11) ◽  
pp. 6649-6654 ◽  
Author(s):  
S U Emerson ◽  
M Lewis ◽  
S Govindarajan ◽  
M Shapiro ◽  
T Moskal ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Viral Hepatitis ◽  
Cdna Clone ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Virulent Virus

scholarly journals Detection of Hepatitis A Virus by the Nucleic Acid Sequence-Based Amplification Technique and Comparison with Reverse Transcription-PCR

2001 ◽  
Vol 67 (12) ◽  
pp. 5593-5600 ◽  
Author(s):  
Julie Jean ◽  
Burton Blais ◽  
André Darveau ◽  
Ismaı̈l Fliss
Keyword(s):  
Nucleic Acid ◽  
Reverse Transcription ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Nucleic Acid Sequence ◽  
Clinical Samples ◽  
Rt Pcr ◽  
Dot Blot ◽  
Reverse Transcription Pcr ◽  
Dot Blot Assay

ABSTRACT A nucleic acid sequence-based amplification (NASBA) technique for the detection of hepatitis A virus (HAV) in foods was developed and compared to the traditional reverse transcription (RT)-PCR technique. Oligonucleotide primers targeting the VP1 and VP2 genes encoding the major HAV capsid proteins were used for the amplification of viral RNA in an isothermal process resulting in the accumulation of RNA amplicons. Amplicons were detected by hybridization with a digoxigenin-labeled oligonucleotide probe in a dot blot assay format. Using the NASBA, as little as 0.4 ng of target RNA/ml was detected per comparison to 4 ng/ml for RT-PCR. When crude HAV viral lysate was used, a detection limit of 2 PFU (4 × 102 PFU/ml) was obtained with NASBA, compared to 50 PFU (1 × 104PFU/ml) obtained with RT-PCR. No interference was encountered in the amplification of HAV RNA in the presence of excess nontarget RNA or DNA. The NASBA system successfully detected HAV recovered from experimentally inoculated samples of waste water, lettuce, and blueberries. Compared to RT-PCR and other amplification techniques, the NASBA system offers several advantages in terms of sensitivity, rapidity, and simplicity. This technique should be readily adaptable for detection of other RNA viruses in both foods and clinical samples.

Disinfection of Human Enteric Viruses in Water by Copper: Silver and Reduced Levels of Chlorine

1993 ◽  
Vol 27 (3-4) ◽  
pp. 351-355 ◽  
Author(s):  
Albert Bosch ◽  
José M. Díez ◽  
F. Xavier Abad
Keyword(s):  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Tap Water ◽  
Silver Ions ◽  
Water Systems ◽  
Free Chlorine ◽  
Viral Pathogens ◽  
Human Rotavirus ◽  
Low Levels ◽  
Total Elimination

Electrolytically generated copper: silver ions were evaluated in combination with low levels of chlorine for their ability to reduce the infectivity of hepatitis A virus, human rotavirus, adenovirus and poliovirus seeded in well and tap water. Overall, hepatitis A virus and rotavirus showed less than 2.6 log10 titre reduction for concentrations of 1 mg/l of free chlorine. For free chlorine concentrations of 0.5 mg/l or lower, with or without copper: silver ions, both of these viral strains suffered little inactivation. Poliovirus showed more than 4 log10 titre reduction in the presence of copper: silver combined with 0.5 mg/l of free chlorine, or 1 mg/l of free chlorine alone. Copper: silver ions (700:70 µg/l) reduced the infectivity of poliovirus. Although adenovirus was more efficiently inactivated than rotavirus or hepatitis A virus, it persisted longer than poliovirus under the same treatments, and its infectivity was never completely removed. The addition of copper: silver ions to reduce the levels of free chlorine do not ensure the total elimination of viral pathogens from water systems.

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