Survival and Transfer of Murine Norovirus 1, a Surrogate for Human Noroviruses, during the Production Process of Deep-Frozen Onions and Spinach

2008 ◽  
Vol 71 (8) ◽  
pp. 1590-1597 ◽  
Author(s):  
LEEN BAERT ◽  
MIEKE UYTTENDAELE ◽  
MATTIAS VERMEERSCH ◽  
ELS VAN COILLIE ◽  
JOHAN DEBEVERE
Keyword(s):  
Plaque Assay ◽  
Wash Water ◽  
Murine Norovirus ◽  
Pcr Assay ◽  
Log Reduction ◽  
Onion Bulbs ◽  
Reverse Transcription Pcr ◽  
Demineralized Water ◽  
Water Ph ◽  
Spinach Leaves

The reduction of murine norovirus 1 (MNV-1) on onions and spinach by washing was investigated as was the risk of contamination during the washing procedure. To decontaminate wash water, the industrial sanitizer peracetic acid (PAA) was added to the water, and the survival of MNV-1 was determined. In contrast to onions, spinach undergoes a heat treatment before freezing. Therefore, the resistance of MNV-1 to blanching of spinach was examined. MNV-1 genomic copies were detected with a real-time reverse transcription PCR assay in PAA-treated water and blanched spinach, and PFUs (representing infectious MNV-1 units) were determined with a plaque assay. A ≤1-log reduction in MNV-1 PFUs was achieved by washing onion bulbs and spinach leaves. More than 3 log PFU of MNV-1 was transmitted to onion bulbs and spinach leaves when these vegetables were washed in water containing approximately 5 log PFU/ml. No decline of MNV-1 occurred in used industrial spinach wash water after 6 days at room temperature. A concentration of 20 ppm of PAA in demineralized water (pH 4.13) and in potable water (pH 7.70) resulted in reductions of 2.88 ± 0.25 and 2.41 ± 0.18 log PFU, respectively, after 5 min of exposure, but no decrease in number of genomic copies was observed. No reduction of MNV-1 PFUs was observed on frozen onions or spinach during storage for 6 months. Blanching spinach (80°C for 1 min) resulted in at least 2.44-log reductions of infectious MNV-1, but many genomic copies were still present.

scholarly journals Effect of Grape Seed Extract on Human Norovirus GII.4 and Murine Norovirus 1 in Viral Suspensions, on Stainless Steel Discs, and in Lettuce Wash Water

2012 ◽  
Vol 78 (21) ◽  
pp. 7572-7578 ◽  
Author(s):  
Dan Li ◽  
Leen Baert ◽  
Dongsheng Zhang ◽  
Ming Xia ◽  
Weiming Zhong ◽  
...  
Keyword(s):  
Specific Binding ◽  
Plaque Assay ◽  
Oxygen Demand ◽  
Grape Seed Extract ◽  
Grape Seed ◽  
Seed Extract ◽  
Wash Water ◽  
Enzyme Linked Immunosorbent Assay ◽  
Murine Norovirus ◽  
Reverse Transcription Pcr

ABSTRACTThe anti-norovirus (anti-NoV) effect of grape seed extract (GSE) was examined by plaque assay for murine norovirus 1 (MNV-1), cell-binding reverse transcription-PCR for human NoV GII.4, and saliva-binding enzyme-linked immunosorbent assay for human NoV GII.4 P particles, with or without the presence of interfering substances (dried milk and lettuce extract). GSE at 0.2 and 2 mg/ml was shown to reduce the infectivity of MNV-1 (>3-log PFU/ml) and the specific binding ability of NoV GII.4 to Caco-2 cells (>1-log genomic copies/ml), as well as of its P particles to salivary human histo-blood group antigen receptors (optical density at 450 nm of >0.8). These effects were decreased as increasing concentrations of dried milk (0.02 and 0.2%) or lettuce extract were added. Under an electron microscope, human NoV GII.4 virus-like particles showed inflation and deformation after treatment with GSE. Under conditions that simulated applications in the food industry, the anti-NoV effect of GSE using MNV-1 as a target organism was shown to be limited in surface disinfection (<1-log PFU/ml, analyzed in accordance with EN 13697:2001). However, a 1.5- to 2-log PFU/ml reduction in MNV-1 infectivity was noted when 2 mg of GSE/ml was used to sanitize water in the washing bath of fresh-cut lettuce, and this occurred regardless of the chemical oxygen demand (0 to 1,500 mg/ml) of the processing water.

Comparative Efficacy of Seven Hand Sanitizers against Murine Norovirus, Feline Calicivirus, and GII.4 Norovirus†

2010 ◽  
Vol 73 (12) ◽  
pp. 2232-2238 ◽  
Author(s):  
GEUN WOO PARK ◽  
LESLIE BARCLAY ◽  
DAVID MACINGA ◽  
DUANE CHARBONNEAU ◽  
CHARLES A. PETTIGREW ◽  
...  
Keyword(s):  
Plaque Assay ◽  
Feline Calicivirus ◽  
Murine Norovirus ◽  
Comparative Efficacy ◽  
Pcr Assay ◽  
Reverse Transcription Pcr ◽  
Source Of Infection ◽  
Fecal Extract ◽  
Virucidal Efficacy

Contaminated hands or inanimate surfaces can act as a source of infection during outbreaks of human norovirus infection. We evaluated the virucidal efficacy of seven hand sanitizers containing various active ingredients, such as ethanol, triclosan, and chlorhexidine, and compared their effectiveness against feline calicivirus (FCV), murine norovirus (MNV), and a GII.4 norovirus fecal extract. We also tested the efficacy of 50, 70, and 90% of ethanol and isopropanol. Reduction of viral infectivity was measured by plaque assay, and the number of genomic copies was determined with a TaqMan real-time reverse transcription PCR assay. Based on the results of a quantitative suspension test, only one ethanol-based product (72% ethanol, pH 2.9) and one triclosan-based product (0.1% triclosan, pH 3.0) reduced the infectivity of both MNV and FCV (by &gt;2.6 and ≥3.4 log units, respectively). Four of the seven products were effective against either MNV or FCV, whereas chlorhexidine was ineffective against both viruses. For these hand sanitizers, no correlation was found between reduced infectivity and decline of viral RNA. Ethanol and isopropanol concentrations ≥70% reduced the infectivity of MNV by ≥2.6 log units, whereas 50 and 70% ethanol reduced the infectivity of FCV by ≥2.2 log units after exposure for 5 min. The susceptibility of FCV to low pH and the relative high susceptibility of MNV to alcohols suggest that both surrogate viruses should be considered for in vitro testing of hand sanitizers.

Attachment of Noroviruses to Stainless Steel and Their Inactivation, Using Household Disinfectants

2010 ◽  
Vol 73 (2) ◽  
pp. 400-404 ◽  
Author(s):  
MARYLINE GIRARD ◽  
SOLANGE NGAZOA ◽  
KIRSTEN MATTISON ◽  
JULIE JEAN
Keyword(s):  
Stainless Steel ◽  
Relative Humidity ◽  
Real Time ◽  
Reverse Transcription ◽  
Plaque Assay ◽  
Pcr Assay ◽  
Log Reduction ◽  
Reverse Transcription Pcr ◽  
Elution Buffer ◽  
The Impact

The aims of this study were (i) to evaluate the impact of pH and relative humidity on the attachment of norovirus (NoV) to fomites and (ii) to evaluate the effectiveness of different household disinfectants on NoV attached to fomites. Plaque assay and/or real-time reverse transcription PCR assay were used to determine the amount of murine and human NoV attached to stainless steel disks, i.e., the amount removed by sonication in elution buffer but not by surface rinses with water only. An enzymatic pretreatment was used for both human and murine NoV before the real-time reverse transcription PCR assay to avoid detection of RNA associated with inactivated virus. For both murine and human NoV, maximum attachment was obtained after a contact time of 10 min. Attachment of NoV to stainless steel does not appear to be affected by pH, although murine NoV was less attached (&lt;2 log units) at pH 9 and at low relative humidity (25%) than was human NoV (3 log units). Sodium hypochlorite (3%) was the most effective disinfectant, producing a greater than 3-log reduction after 10 min compared with less than a 1-log reduction after treatment with quaternary ammonium compounds and ethoxylated alcohols. Murine NoV was more sensitive than human NoV to disinfectants by approximately 1 to 2 log units. These results will help improve strategies for decontaminating surfaces harboring NoV and thus reduce the incidence of illness caused by these pathogens in the food sector and domestic environments.

scholarly journals Evaluation of the Porcine Gastric Mucin Binding Assay for High-Pressure-Inactivation Studies Using Murine Norovirus and Tulane Virus

2014 ◽  
Vol 81 (2) ◽  
pp. 515-521 ◽  
Author(s):  
Xinhui Li ◽  
Haiqiang Chen
Keyword(s):  
Culture Medium ◽  
Binding Assay ◽  
Plaque Assay ◽  
Treatment Temperature ◽  
Gastric Mucin ◽  
Murine Norovirus ◽  
Pcr Assay ◽  
Log Reduction ◽  
Porcine Gastric Mucin ◽  
Tulane Virus

ABSTRACTWe compared the results of high-hydrostatic-pressure (HHP) inactivation of murine norovirus type 1 (MNV-1) and Tulane virus (TV) obtained by a porcine gastric mucin binding assay followed by quantitative reverse transcription-PCR (referred to here as the PGM-MB/PCR assay) and a plaque assay and evaluated HHP inactivation of a human norovirus (HuNoV) genogroup I genotype 1 (GI.1) strain and a HuNoV GII.4 strain by using the PGM-MB/PCR assay. Viruses were treated at different pressure levels for 2 min at 4 or 21°C in culture medium of neutral pH and in culture medium of pH 4 at 21°C. The log reductions of infectious MNV-1 and TV particles caused by HHP were assessed using the PGM-MB/PCR and plaque assays, while the log reductions of HuNoVs were assessed by the PGM-MB/PCR assay only. For TV and MNV-1, the two pressure inactivation curves obtained using the plaque and PGM-MB/PCR assays were almost identical at ≤2-log-reduction levels regardless of the treatment temperature and pH. Further increasing the pressure over the 2-log-reduction level resulted in higher log reductions of TV and MNV-1, as assessed by the plaque assay, but did not increase the log reductions, as assessed by the PGM-MB/PCR assay. HHP treatments could achieve maximum reductions of ∼3 and 3.5 log units for GI.1 and GII.4, respectively, as assessed by the PGM-MB/PCR assay. On the basis of these results, it can reasonably be concluded that the PGM-MB/PCR assay would very likely be able to estimate HHP inactivation of HuNoV at ≤2-log-reduction levels. It would also likely conservatively quantify HHP inactivation of the GI.1 strain at 2- to 3-log-reduction levels and the GII.4 strain at 2- to 3.5-log-reduction levels.

scholarly journals Study of kerosene caustic wash process for jet fuel production

2021 ◽  
Vol 68 (1) ◽  
Author(s):  
Ahmed Mohamed Selim Abdelhamid ◽  
Hamdy Abdel-Aziz Mustafa
Keyword(s):  
Treatment Process ◽  
Naphthenic Acid ◽  
Naphthenic Acids ◽  
Jet Fuel ◽  
Wash Water ◽  
Water Volume ◽  
Water Type ◽  
Noticeable Effect ◽  
Demineralized Water ◽  
Water Ph

AbstractCaustic wash is one of many industrial processes that are used to produce jet fuel. In this study, an analysis of the key parameters of the kerosene caustic wash process was conducted to improve the total performance of the treatment process. The investigated parameters are caustic concentration (from 0.03 to 3.0 wt%), caustic volume (from 110% of theoretical to 250%), number of treatment stages (one and two stages), wash water type (demineralized water and alkaline soft water), and wash water volume (10% and 30% of kerosene feed volume). Results revealed that the reaction between sodium hydroxide and naphthenic acids is a diffusion-controlled chemical reaction. The diluted caustic solutions (0.5 wt%) are better than the concentrated ones (3 wt%). Higher excess caustic volume has a slight effect on kerosene acidity. Performing the caustic treatment process in one stage is sufficient, and the two-stage process has no effect on acidity. Washing caustic-treated kerosene with demineralized water (pH=7) has a slight adverse effect on kerosene acidity. Increasing the demineralized water volume results in a slight increase in the acidity of the treated kerosene. Wash water should be slightly alkaline (pH 7.5–8) to prevent the reverse reaction of sodium naphthenates back into naphthenic acid. Increasing wash water volume (more than 10 vol% of kerosene feed) has no noticeable effect on the water content of treated kerosene.

Inactivation of Norovirus Surrogates on Surfaces and Raspberries by Steam-Ultrasound Treatment

2012 ◽  
Vol 75 (2) ◽  
pp. 376-381 ◽  
Author(s):  
ANNA CHARLOTTE SCHULTZ ◽  
KATRINE UHRBRAND ◽  
BIRGIT NØRRUNG ◽  
ANDERS DALSGAARD
Keyword(s):  
Treatment Time ◽  
Plaque Assay ◽  
Disease Outbreaks ◽  
Ultrasound Treatment ◽  
Murine Norovirus ◽  
Power Ultrasound ◽  
Real Time Quantitative Pcr ◽  
Log Reduction ◽  
High Power Ultrasound ◽  
Plastic Surfaces

Human disease outbreaks caused by norovirus (NoV) following consumption of contaminated raspberries are an increasing problem. An efficient method to decontaminate the fragile raspberries and the equipment used for processing would be an important step in ensuring food safety. A potential surface treatment that combines pressurized steam and high-power ultrasound (steam-ultrasound) was assessed for its efficacy to inactivate human NoV surrogates: coliphage (MS2), feline calicivirus (FCV), and murine norovirus (MNV) inoculated on plastic surfaces and MS2 inoculated on fresh raspberries. The amounts of infectious virus and viral genomes were determined by plaque assay and reverse transcription–real time quantitative PCR (RT-qPCR), respectively. On plastic surfaces, an inactivation of &gt;99.99% was obtained for both MS2 and FCV, corresponding to a 9.1-log and &gt;4.8-log reduction after 1 or 3 s of treatment, respectively; while a 3.7-log (99.97%) reduction of MNV was reached after 3 s of treatment. However, on fresh raspberries only a 1-log reduction (~89%) of MS2 could be achieved after 1 s of treatment, at which point damage to the texture of the fresh raspberries was evident. Increasing treatment time (0 to 3 s) resulted in negligible reductions of viral genome titers of MS2, FCV, and MNV on plastic surfaces as well as of MS2 inoculated on raspberries. Steam-ultrasound treatment in its current format does not appear to be an appropriate method to achieve sufficient decontamination of NoV-contaminated raspberries. However, steam-ultrasound may be used to decontaminate smooth surface areas and utensils in food production and processing environments.

scholarly journals Inactivation and UV Disinfection of Murine Norovirus with TiO2 under Various Environmental Conditions

2008 ◽  
Vol 74 (7) ◽  
pp. 2111-2117 ◽  
Author(s):  
JungEun Lee ◽  
KyungDuk Zoh ◽  
GwangPyo Ko
Keyword(s):  
Real Time ◽  
Salt Concentration ◽  
Environmental Conditions ◽  
Plaque Assay ◽  
Surface Characteristics ◽  
Uv Disinfection ◽  
Murine Norovirus ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Stool Suspension

ABSTRACT We studied inactivation and UV disinfection of murine norovirus (MNV) as a surrogate for human norovirus. We investigated the effects of different surface characteristics, temperatures, and NaCl concentrations on MNV survival using both a plaque assay and a real-time TaqMan reverse transcription (RT)-PCR assay. MNV survived more than 40 days on diaper material, on gauze, and in a stool suspension. Compared to inactivation at lower temperatures (−20 and 4°C), inactivation of MNV was greater at higher temperatures (18 and 30°C). On the surface of both gauze and diaper material, there was a <2-log10 reduction in the amount of infectious MNV in 40 days after incubation at both −20 and 4°C, compared to a >5-log10 reduction after incubation at 30°C in 24 days. MNV survived better in a stool suspension than on the surface of gauze or diaper material. A higher salt concentration increased the rate of inactivation of MNV. In 72 h, <0.3-, 1.5-, and 2.5-log10 reductions in the amount of infectious MNV occurred in distilled water and 0.5 and 1 M NaCl, respectively. We observed only minor reductions in the numbers of viral RNA copies as quantified by real-time TaqMan RT-PCR regardless of the temperature, the salt concentration, or the suspending medium. We also evaluated UV disinfection of infectious MNV with and without TiO2. The amount of MNV was significantly reduced by 254-nm UV with and without TiO2. When 25 mJ/cm2 UV was used, 3.3- and 3.6-log10 reductions in the amounts of infectious MNV occurred with and without TiO2, respectively. Our results demonstrate that MNV can persist in various environmental conditions and can be efficiently controlled by UV disinfection.

Evaluation of Murine Norovirus Persistence in Environments Relevant to Food Production and Processing

2011 ◽  
Vol 74 (11) ◽  
pp. 1847-1851 ◽  
Author(s):  
S. FALLAHI ◽  
K. MATTISON
Keyword(s):  
Stainless Steel ◽  
Food Production ◽  
Room Temperature ◽  
Potable Water ◽  
Plaque Assay ◽  
The Other ◽  
Murine Norovirus ◽  
Human Norovirus ◽  
Log Reduction ◽  
Virus Survival

Human norovirus (NoV) causes outbreaks of acute gastroenteritis associated with many ready-to-eat foods, including fresh produce. Effective inactivation procedures must consider virus survival under conditions of produce production and processing. This study aimed to investigate the persistence of NoV in a variety of environments, using murine NoV (MNV) as a surrogate for NoV. MNV was incubated for up to 42 days at room temperature on stainless steel disks, on lettuce, on soil, and in potable water and titers determined by plaque assay. A 1-log reduction of MNV infectivity was observed after 29 days in water, 4 days on lettuce, 12 days on soil, and 15 days on stainless steel disks. MNV survived longer in water than in any of the other environments, indicating that drying may contribute to NoV inactivation. MNV genomes were not significantly reduced for up to 42 days, suggesting that genomic detection is not a reliable indicator of viability. Overall, our findings provide valuable information regarding the potential for NoV transmission in the food supply.

scholarly journals Detection of Murine Norovirus 1 by Using Plaque Assay, Transfection Assay, and Real-Time Reverse Transcription-PCR before and after Heat Exposure

2007 ◽  
Vol 74 (2) ◽  
pp. 543-546 ◽  
Author(s):  
Leen Baert ◽  
Christiane E. Wobus ◽  
Els Van Coillie ◽  
Larissa B. Thackray ◽  
Johan Debevere ◽  
...  
Keyword(s):  
Real Time ◽  
Reverse Transcription ◽  
Detrimental Effect ◽  
Heat Exposure ◽  
Plaque Assay ◽  
Heat Inactivation ◽  
Virus Infectivity ◽  
Murine Norovirus ◽  
Reverse Transcription Pcr ◽  
Before And After

ABSTRACT The correlation between the detection of murine norovirus 1 RNA by real-time reverse transcription-PCR and the infectivity by plaque assay before and after heat exposure (80°C) was examined. No correlation was found in the current study. Moreover, heat inactivation had a much stronger detrimental effect on virus infectivity than on the integrity of the viral genome.

Recovery and Disinfection of Two Human Norovirus Surrogates, Feline Calicivirus and Murine Norovirus, from Hard Nonporous and Soft Porous Surfaces

2015 ◽  
Vol 78 (10) ◽  
pp. 1842-1850 ◽  
Author(s):  
THOMAS YEARGIN ◽  
ANGELA FRASER ◽  
GUOHUI HUANG ◽  
XIUPING JIANG
Keyword(s):  
Sodium Hypochlorite ◽  
Limit Of Detection ◽  
Plaque Assay ◽  
Viral Rna ◽  
Feline Calicivirus ◽  
Murine Norovirus ◽  
Human Norovirus ◽  
Surface Type ◽  
Log Reduction ◽  
Porous Surfaces

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.

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