Testing for Human Norovirus and Recovery of Process Control in Outbreak-Associated Produce Items

2017 ◽  
Vol 81 (1) ◽  
pp. 105-114 ◽  
Author(s):  
Kaoru Hida ◽  
Efstathia Papafragkou ◽  
Michael Kulka

ABSTRACT The development of rapid and sensitive detection methods for human noroviruses (HuNoV) in produce items is critical, especially with the recent rise in outbreaks associated with this food commodity. In this study, 50-g portions of various produce items linked to a norovirus outbreak (celery, cucumber, lettuce, grapes, and radish) were artificially inoculated with murine norovirus (MNV-1) and concentrated either by ultracentrifugation or polyethylene glycol (PEG) precipitation after elution with an alkaline Tris–glycine–beef extract buffer supplemented with pectinase. As a viral concentration step following virus elution and clarification, ultracentrifugation yielded a faster method (<8 h, including reverse transcription quantitative PCR), with MNV-1 recoveries similar to or better, than those obtained with PEG precipitation. The addition of polyvinylpyrrolidone to the elution buffer, to remove polyphenolic inhibitors, improved MNV-1 recoveries by over two- and fivefold for cucumber and grapes, respectively. However, despite MNV-1 recoveries ranging from 10 to 38% as calculated with 10-fold diluted RNA, contaminating HuNoV was not detected in any of the outbreak-associated samples tested. For store-bought produce samples, the limit of detection for artificially seeded HuNoV GII.4 was determined to be 103 copies per 50 g, with reproducible detection achieved in grapes, radish, and celery. The results support the use of ultracentrifugation as an alternative approach to PEG precipitation to concentrate norovirus from a variety of produce items.

2014 ◽  
Vol 80 (18) ◽  
pp. 5743-5751 ◽  
Author(s):  
Theresa Cromeans ◽  
Geun Woo Park ◽  
Veronica Costantini ◽  
David Lee ◽  
Qiuhong Wang ◽  
...  

ABSTRACTHuman norovirus is the leading cause of epidemic and sporadic acute gastroenteritis. Since no cell culture method for human norovirus exists, cultivable surrogate viruses (CSV), including feline calicivirus (FCV), murine norovirus (MNV), porcine enteric calicivirus (PEC), and Tulane virus (TuV), have been used to study responses to inactivation and disinfection methods. We compared the levels of reduction in infectivities of CSV and Aichi virus (AiV) after exposure to extreme pHs, 56°C heating, alcohols, chlorine on surfaces, and high hydrostatic pressure (HHP), using the same matrix and identical test parameters for all viruses, as well as the reduction of human norovirus RNA levels under these conditions. At pH 2, FCV was inactivated by 6 log10units, whereas MNV, TuV, and AiV were resistant. All CSV were completely inactivated at 56°C within 20 min. MNV was inactivated 5 log10units by alcohols, in contrast to 2 and 3 log10units for FCV and PEC, respectively. TuV and AiV were relatively insensitive to alcohols. FCV was reduced 5 log10units by 1,000 ppm chlorine, in contrast to 1 log10unit for the other CSV. All CSV except FCV, when dried on stainless steel surfaces, were insensitive to 200 ppm chlorine. HHP completely inactivated FCV, MNV, and PEC at ≥300 MPa, and TuV at 600 MPa, while AiV was completely resistant to HHP up to 800 MPa. By reverse transcription-quantitative PCR (RT-qPCR), genogroup I (GI) noroviruses were more sensitive than GII noroviruses to alcohols, chlorine, and HHP. Although inactivation profiles were variable for each treatment, TuV and MNV were the most resistant CSV overall and therefore are the best candidates for studying the public health outcomes of norovirus infections.


2010 ◽  
Vol 73 (9) ◽  
pp. 1651-1657 ◽  
Author(s):  
HYEONJIN PARK ◽  
MINJUNG KIM ◽  
GWANGPYO KO

We evaluated and optimized each step in an analytical method for detecting norovirus from various foods. We characterized the buffers needed for eluting norovirus from foods such as ham and lettuce. Two different concentration methods, polyethylene glycol (PEG) precipitation and hollow fiber ultrafiltration (HUF), were compared using both murine norovirus (MNV) and human norovirus (HuNoV). For PEG precipitation, an elution buffer containing 3% beef extract (pH 7.1) was more suitable than 0.05 M glycine plus 0.14 M NaCl (pH 7.5), and the recovery efficiency increased with increasing molecular weight of PEG. To determine the optimal buffer for concentrating norovirus by HUF, glycine buffers with different pH values and ionic strengths were examined as elution buffers. Overall, HUF was more efficient for norovirus recovery than was PEG precipitation. Because there was a significant positive correlation between MNV and HuNoV results, MNV could be a useful surrogate for detecting HuNoV in foods.


2018 ◽  
Vol 81 (9) ◽  
pp. 1432-1438 ◽  
Author(s):  
ADRIENNE E. H. SHEARER ◽  
KALMIA E. KNIEL

ABSTRACTViral contamination can compromise the safety of water utilized for direct consumption, produce irrigation, and postharvest washing of produce. Zero-valent iron (ZVI) is used commercially for chemical remediation of water and has been demonstrated to remove some biological contaminants from water in laboratory and field studies. This study investigated the efficacy of ZVI to remove human norovirus surrogates, Tulane virus (TV) and murine norovirus (MNV), from water and to characterize the reversibility and nature of viral association with ZVI. Genomic material of TV and MNV recovered from the effluent of inoculated water treatment columns containing a 1:1 mixture of ZVI and sand was 2 and 3 log, respectively, less than that recovered from the effluent of treatment columns containing only sand. Elution buffers (citrate buffers, pH 4 and 7, and virus elution buffer, pH 9.5, with and without added 1 M NaCl) did not increase recovery of infectious TV and MNV from ZVI as compared with elution with water alone. TV-inoculated lettuce washed with water in the presence of ZVI yielded 1.5 to 2 log fewer infectious TV from washwater as compared with lettuce washed with water alone or in the presence of sand. These data demonstrate the enhanced removal of human norovirus surrogates, TV and MNV, from water by ZVI and provide indications that unrecovered viruses are not readily disassociated from ZVI by buffers of various pH and ionic strength. These findings warrant further investigation into larger-scale simulations of water remediation of viral contaminants for potential application in the treatment of water used for drinking, irrigation, and food processing.


2015 ◽  
Vol 78 (10) ◽  
pp. 1842-1850 ◽  
Author(s):  
THOMAS YEARGIN ◽  
ANGELA FRASER ◽  
GUOHUI HUANG ◽  
XIUPING JIANG

Human norovirus is a leading cause of foodborne disease and can be transmitted through many routes, including environmental exposure to fomites. In this study, both the recovery and inactivation of two human norovirus surrogates, feline calicivirus (FCV) and murine norovirus (MNV), on hard nonporous surfaces (glass) and soft porous surfaces (polyester and cotton) were evaluated by both plaque assay and reverse transcription quantitative PCR method. Two disinfectants, sodium hypochlorite (8.25%) and accelerated hydrogen peroxide (AHP, at 4.25%) were evaluated for disinfection efficacy. Five coupons per surface type were used to evaluate the recovery of FCV and MNV by sonication and stomaching and the disinfection of each surface type by using 5 ml of disinfectant for a contact time of 5 min. FCV at an initial titer of ca. 7 log PFU/ml was recovered from glass, cotton, and polyester at 6.2, 5.4, and 3.8 log PFU/ml, respectively, compared with 5.5, 5.2, and 4.1 log PFU/ml, respectively, for MNV with an initial titer of ca. 6 log PFU/ml. The use of sodium hypochlorite (5,000 ppm) was able to inactivate both FCV and MNV (3.1 to 5.5 log PFU/ml) below the limit of detection on all three surface types. AHP (2,656 ppm) inactivated FCV (3.1 to 5.5 log PFU/ml) below the limit of detection for all three surface types but achieved minimal inactivation of MNV (0.17 to 1.37 log PFU/ml). Reduction of viral RNA by sodium hypochlorite corresponded to 2.72 to 4.06 log reduction for FCV and 2.07 to 3.04 log reduction for MNV on all three surface types. Reduction of viral RNA by AHP corresponded to 1.89 to 3.4 log reduction for FCV and 0.54 to 0.85 log reduction for MNV. Our results clearly indicate that both virus and surface types significantly influence recovery efficiency and disinfection efficacy. Based on the performance of our proposed testing method, an improvement in virus recovery will be needed to effectively validate virus disinfection of soft porous surfaces.


Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 3985
Author(s):  
Nan Wan ◽  
Yu Jiang ◽  
Jiamei Huang ◽  
Rania Oueslati ◽  
Shigetoshi Eda ◽  
...  

A sensitive and efficient method for microRNAs (miRNAs) detection is strongly desired by clinicians and, in recent years, the search for such a method has drawn much attention. There has been significant interest in using miRNA as biomarkers for multiple diseases and conditions in clinical diagnostics. Presently, most miRNA detection methods suffer from drawbacks, e.g., low sensitivity, long assay time, expensive equipment, trained personnel, or unsuitability for point-of-care. New methodologies are needed to overcome these limitations to allow rapid, sensitive, low-cost, easy-to-use, and portable methods for miRNA detection at the point of care. In this work, to overcome these shortcomings, we integrated capacitive sensing and alternating current electrokinetic effects to detect specific miRNA-16b molecules, as a model, with the limit of detection reaching 1.0 femto molar (fM) levels. The specificity of the sensor was verified by testing miRNA-25, which has the same length as miRNA-16b. The sensor we developed demonstrated significant improvements in sensitivity, response time and cost over other miRNA detection methods, and has application potential at point-of-care.


Biosensors ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 85
Author(s):  
Wassa Waiwinya ◽  
Thitirat Putnin ◽  
Dechnarong Pimalai ◽  
Wireeya Chawjiraphan ◽  
Nuankanya Sathirapongsasuti ◽  
...  

An immobilization-free electrochemical sensor coupled with a graphene oxide (GO)-based aptasensor was developed for glycated human serum albumin (GHSA) detection. The concentration of GHSA was monitored by measuring the electrochemical response of free GO and aptamer-bound GO in the presence of glycated albumin; their currents served as the analytical signals. The electrochemical aptasensor exhibited good performance with a base-10 logarithmic scale. The calibration curve was achieved in the range of 0.01–50 µg/mL. The limit of detection (LOD) was 8.70 ng/mL. The developed method was considered a one-drop measurement process because a fabrication step and the probe-immobilization process were not required. This simple sensor offers a cost-effective, rapid, and sensitive detection method, and could be an alternative approach for determination of GHSA levels.


1987 ◽  
Vol 70 (5) ◽  
pp. 874-878 ◽  
Author(s):  
James Fleeker

Abstract Two solid-phase enzyme immunoassays were developed to measure 2,4-dichlorophenoxyacetic acid (2,4-D), using 2 sets of structurally distinct immunogens and enzyme ligands. The 2,4-D analog, 2-methyl- 4-chlorophenoxyacetic acid (MCPA), gave a similar response with both methods, whereas other phenoxy herbicides cross-reacted differently. In method A, the aromatic moiety of 2,4-D was distal from the carrier protein and labeled enzyme, whereas in method B, the acetic acid portion of the herbicide was distal. The use of both methods to screen for this herbicide in ground water and municipal and river water reduced the number of false-positive responses. Water sources having a low background response could be monitored with either method alone. When a concentration step, with disposable C18 extraction columns, was used, the limit of sensitivity was 5 ng/L,. Method A was the more sensitive of the 2 methods with a limit of detection of 10 j*g/L without the concentration step


Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 416
Author(s):  
Robert Creutznacher ◽  
Thorben Maass ◽  
Patrick Ogrissek ◽  
Georg Wallmann ◽  
Clara Feldmann ◽  
...  

Glycan–protein interactions are highly specific yet transient, rendering glycans ideal recognition signals in a variety of biological processes. In human norovirus (HuNoV) infection, histo-blood group antigens (HBGAs) play an essential but poorly understood role. For murine norovirus infection (MNV), sialylated glycolipids or glycoproteins appear to be important. It has also been suggested that HuNoV capsid proteins bind to sialylated ganglioside head groups. Here, we study the binding of HBGAs and sialoglycans to HuNoV and MNV capsid proteins using NMR experiments. Surprisingly, the experiments show that none of the norovirus P-domains bind to sialoglycans. Notably, MNV P-domains do not bind to any of the glycans studied, and MNV-1 infection of cells deficient in surface sialoglycans shows no significant difference compared to cells expressing respective glycans. These findings redefine glycan recognition by noroviruses, challenging present models of infection.


2021 ◽  
Vol 368 (6) ◽  
Author(s):  
Liwen Zhang ◽  
Qingyu Lv ◽  
Yuling Zheng ◽  
Xuan Chen ◽  
Decong Kong ◽  
...  

ABSTRACT T-2 is a common mycotoxin contaminating cereal crops. Chronic consumption of food contaminated with T-2 toxin can lead to death, so simple and accurate detection methods in food and feed are necessary. In this paper, we establish a highly sensitive and accurate method for detecting T-2 toxin using AlphaLISA. The system consists of acceptor beads labeled with T-2-bovine serum albumin (BSA), streptavidin-labeled donor beads and biotinylated T-2 antibodies. T-2 in the sample matrix competes with T-2-BSA for antibodies. Adding biotinylated antibodies to the test well followed by T-2 and T-2-BSA acceptor beads yielded a detection range of 0.03–500 ng/mL. The half-maximal inhibitory concentration was 2.28 ng/mL and the coefficient of variation was <10%. In addition, this method had no cross-reaction with other related mycotoxins. This optimized method for extracting T-2 from food and feed samples achieved a recovery rate of approximately 90% in T-2 concentrations as low as 1 ng/mL, better than the performance of a commercial ELISA kit. This competitive AlphaLISA method offers high sensitivity, good specificity, good repeatability and simple operation for detecting T-2 toxin in food and feed.


2009 ◽  
Vol 72 (12) ◽  
pp. 2547-2552 ◽  
Author(s):  
HEE-YEON KIM ◽  
HYEUN-JIN PARK ◽  
GWANGPYO KO

We investigated the possibility of using hollow-fiber ultrafiltration (HUF) for the simultaneous recovery of multiple microorganisms in food samples. MS2 bacteriophage, E. coli, Bacillus subtilis spores, and murine norovirus (MNV) were each inoculated into 5 liters of either distilled water (DW) or glycine elution buffer and then concentrated using hollow-fiber polysulfone ultrafilters. The resulting concentrates were further analyzed by either cultivation or TaqMan real-time reverse transcription PCR assay. The overall average recovery rates were 7.1% in DW and 17.1% in glycine elution buffer. When the virus, vegetative bacteria, and bacterial spores were simultaneously inoculated into DW, glycine, or Tris-HCl elution buffers, on average 16.8% of inoculated microorganisms were recovered by HUF. The addition of 3% beef extract blocking buffer to HUF increased the total recovery rate to 46.1%, with incremental recovery rates increasing sharply for B. subtilis spores and MNV. Use of HUF resulted in E. coli recovery rates of 68.0% on lettuce and 66.2% on ham and MNV recovery rates of 1.5% on lettuce and 5.8% on ham. Our study demonstrates that HUF can be effective at simultaneously recovering and concentrating diverse bacterial and viral pathogens from foods.


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