scholarly journals Inactivation of Hepatitis A Virus and Human Norovirus in Clams Subjected to Heat Treatment

2021 ◽  
Vol 11 ◽  
Author(s):  
Cristina Fuentes ◽  
Francisco J. Pérez-Rodríguez ◽  
Aurora Sabrià ◽  
Nerea Beguiristain ◽  
Rosa M. Pintó ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Food Product ◽  
Performance Criterion ◽  
Performance Criteria ◽  
Economic Implications ◽  
Log Reduction ◽  
A Cell ◽  
A Performance

Bivalve mollusk contamination by enteric viruses, especially human noroviruses (HuNoV) and hepatitis A virus (HAV), is a problem with health and economic implications. The aim of the study was the evaluation of the effect of heat treatment in clams (Tawera gayi) experimentally contaminated with HuNoV using a PMA-viability RTqPCR assay to minimize measurement of non-infectious viruses, and used HAV as a model to estimate infectivity loss. Spiked clams were immersed in water at 90°C to ensure that internal meat temperature was maintained above 90°C for at least 5 min. The treatment resulted in >3.89 ± 0.24 log10 TCID50/g reduction of infectious HAV, confirming inactivation. For HuNoV, RTqPCR assays showed log10 reductions of 2.96 ± 0.79 and 2.56 ± 0.56, for GI and GII, respectively, and the use of PMA resulted in an additional log10 reduction for GII, providing a better correlation with risk reduction. In the absence of a cell culture system which could be used to determine HuNoV infectivity reduction, a performance criteria based on PMA-RTqPCR log reduction could be used to evaluate food product safety. According to data from this study, heat treatments of clams which cause reductions >3.5 log10 for GII as measured by PMA-RTqPCR assay may be regarded as an acceptable inactivation treatment, and could be set as a performance criterion to test the effectiveness of other time-temperature inactivation processes.

“In vitro” and in Animal Model Studies on a Double Virus- Inactivated Factor VIII Concentrate

1995 ◽  
Vol 74 (03) ◽  
pp. 868-873 ◽  
Author(s):  
Silvana Arrighi ◽  
Roberta Rossi ◽  
Maria Giuseppina Borri ◽  
Vladimir Lesnikov ◽  
Marina Lesnikov ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Animal Model ◽  
Factor Viii ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Virus Inactivation ◽  
Enveloped Viruses ◽  
Model Studies ◽  
Heat Treated

SummaryTo improve the safety of plasma derived factor VIII (FVIII) concentrate, we introduced a final super heat treatment (100° C for 30 min) as additional virus inactivation step applied to a lyophilized, highly purified FVIII concentrate (100 IU/mg of proteins) already virus inactivated using the solvent/detergent (SID) method during the manufacturing process.The efficiency of the super heat treatment was demonstrated in inactivating two non-lipid enveloped viruses (Hepatitis A virus and Poliovirus 1). The loss of FVIII procoagulant activity during the super heat treatment was of about 15%, estimated both by clotting and chromogenic assays. No substantial changes were observed in physical, biochemical and immunological characteristics of the heat treated FVIII concentrate in comparison with those of the FVIII before heat treatment.

A performance criterion for glass heat treatment

1991 ◽  
Vol 48 (5) ◽  
pp. 201-204
Author(s):  
G. M. Legoshin
Keyword(s):  
Heat Treatment ◽  
Performance Criterion ◽  
Glass Heat ◽  
A Performance

Survival of Hepatitis A Virus on Two-month Stored Freeze-dried Berries

2021 ◽  
Author(s):  
Yan Zhang ◽  
Xueyan Wang ◽  
Y. Carol Shieh
Keyword(s):  
Freeze Drying ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Reduction Rate ◽  
Radiant Heating ◽  
Minimal Processing ◽  
Log Reduction ◽  
C Storage ◽  
Freeze Dried ◽  
Heating Up

Imported berries have contributed to U.S. hepatitis A virus (HAV) infections. Minimal processing by freeze-drying is preferred by industry for preserving food quality, but virus inactivation by this process may be limited. This study investigated HAV survival on strawberries during 24-h freeze-drying followed by 22 ° C-storage. The outer surfaces of strawberry slices were prepared and each inoculated with 5 to 6 log 10 PFU HAV, air-dried 20 min, frozen 1 h at -80 °C, and freeze-dried 24 h with radiant heating up to 36 °C. Infectious HAV levels eluted from berry slices were quantified on FRhK-4 cells grown onto 6-well dishes. Freeze-drying trials (n = 17) with radiant heating inactivated ≤1 log 10 PFU per trial, although HAV-inactivation was significantly greater at 36 ºC than 15 ºC heating ( p < 0.01). Average HAV reduction rate on dried berries continuously decreased as storage time increased, 0.2, 0.09, 0.08, 0.04, 0.04 and 0.03 log-reduction/day at day 2, 7, 14, 28, 42, and 56, respectively, with the cumulated log-reduction divided by storage days. Therefore, the best fit regression for the total/cumulative virus reduction (Y) at any given day (X) is Y= 0.2882X 0.4503 (r² = 0.97), with maximum 2.7 log-reduction on berries throughout the drying and subsequent 2-month storage. HAV showed the greatest decline within the first 14-days of storage of dried berries (approximately 70% weekly reduction from its previous week levels), but the HAV reduction rates were still lower than that occurring on fresh produce.

Inactivation of hepatitis a virus by heat treatment in aqueous solution

1993 ◽  
Vol 41 (1) ◽  
pp. 61-64 ◽  
Author(s):  
Paula Murphy ◽  
Thomas Nowak ◽  
Stanley M. Lemon ◽  
Joachim Hilfenhaus
Keyword(s):  
Heat Treatment ◽  
Aqueous Solution ◽  
Hepatitis A ◽  
Hepatitis A Virus

scholarly journals Utilization of Chimeras between Human (HM-175) and Simian (AGM-27) Strains of Hepatitis A Virus To Study the Molecular Basis of Virulence

1998 ◽  
Vol 72 (9) ◽  
pp. 7467-7475 ◽  
Author(s):  
Gopa Raychaudhuri ◽  
Sugantha Govindarajan ◽  
Max Shapiro ◽  
Robert H. Purcell ◽  
and Suzanne U. Emerson
Keyword(s):  
Cell Culture ◽  
Hepatitis A ◽  
Cultured Cells ◽  
Hepatitis A Virus ◽  
Kinetic Studies ◽  
Simian Virus ◽  
Saguinus Mystax ◽  
Amino Terminal ◽  
A Cell ◽  
Carboxy Terminal

ABSTRACT Chimeras between human (HM-175) and simian (AGM-27) strains of hepatitis A virus (HAV) were constructed to evaluate the effect of the 2C gene of AGM-27 on HAV replication in cell culture and virulence in tamarins (Saguinus mystax) and chimpanzees (Pan troglodytes). Kinetic studies and radioimmunofocus assays demonstrated that replacement of the 2C gene of HAV/7, a cell culture-adapted strain of HM-175, with that of AGM-27 drastically reduced the ability of the virus to replicate in cultured cells. Intragenic chimeras containing AGM-27 sequences in either the 5′ or 3′ half of the 2C gene replicated in cell culture at an intermediate level. Whereas HAV/7 is attenuated for tamarins, a chimera containing the simian virus 2C gene in the HAV/7 background was virulent in tamarins, demonstrating that the simian virus 2C gene alone can confer the phenotype of virulence to an otherwise attenuated virus. Clusters of AGM-27-specific residues near both ends of the 2C protein were required for virulence since a chimera containing AGM-27 sequences in the carboxy-terminal half of 2C was partially attenuated for tamarins while one containing AGM-27 sequences only in the amino-terminal half of 2C was even more attenuated. Chimeras containing either the entire or only the 3′ half of the simian virus 2C gene in the HAV/7 background were attenuated for chimpanzees.

Survival and Persistence of Norovirus, Hepatitis A Virus, and Feline Calicivirus in Marinated Mussels

2004 ◽  
Vol 67 (8) ◽  
pp. 1743-1750 ◽  
Author(s):  
JOANNE HEWITT ◽  
GAIL E. GREENING
Keyword(s):  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Enteric Viruses ◽  
Feline Calicivirus ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Potential Health ◽  
Infectious Dose ◽  
Log Reduction ◽  
Public Health Authorities

Noroviruses (NV) and hepatitis A virus (HAV) are foodborne enteric viruses associated with outbreaks of disease following consumption of raw or lightly cooked bivalve shellfish. Marinated mussels are a popular delicacy, but there is no published information on whether enteric viruses survive the marination process. The survival and persistence of HAV, NV, and a surrogate calicivirus, feline calicivirus (FCV), in marinated mussels over time was determined. NV, HAV, and FCV were inoculated into marinated mussels and marinade liquid and then held at 4°C for up to 4 weeks. Survival of HAV and FCV was quantified by determining the 50% tissue culture infectious dose (TCID50), and these results were correlated with those of the reverse transcription (RT)–PCR assay. The persistence of nonculturable NV was determined by RT–PCR assay only. Over 4 weeks, HAV survived exposure to acid marinade at pH 3.75. There was a 1.7-log reduction in HAV TCID50 titer but no reduction in NV or HAV RT-PCR titer after 4 weeks in marinated mussels. FCV was inactivated in acid conditions although it was still detectable by RT-PCR. To simulate preharvest virus contamination and commercial marination processing, experiments using fresh mussels infected with HAV and NV were performed. HAV and NV persistence was determined using semiquantitative real-time RT-PCR, and HAV infectivity was determined by the TCID50 assay. HAV retained infectivity following simulated commercial marination and exposure to acid conditions over 4 weeks. The survival of pathogenic enteric viruses in marinated mussels constitutes a potential health risk and so is of concern to public health authorities.

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