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1.
Food Environ Virol ; 11(2): 178-183, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30747345

RESUMO

Although the effects of heavy metals on the behavior, including infectivity, of bacteria have been studied, little information is available about their effects on enteric viruses. We report an investigation of effects on the biosynthesis of human adenoviruses (HAdV) and hepatitis A (HAV) of waters contaminated with mineral waste following an environmental disaster in Mariana City, Minas Gerais State, Brazil. The study area was affected on November 5, 2015, by 60 million m3 of mud (containing very high concentrations of iron salts) from a mining reservoir (Fundão), reaching the Gualaxo do Norte River (sites evaluated in this study), the "Rio Doce" River and finally the Atlantic Ocean. We found substantial counts of infectious HAdV and HAV (by qPCR) in all sampled sites from Gualaxo do Norte River, indicating poor basic sanitation in this area. The effects of iron on viral infection processes were evaluated using HAdV-2 and HAV-175, as DNA and RNA enteric virus models, respectively, propagated in the laboratory and exposed to this contaminated water. Experiments in field and laboratory scales found that the numbers of plaque forming units (PFU) of HAdV and HAV were significantly higher in contaminated water with high iron concentrations than in waters with low iron concentration (< 20 µg/L of iron). These findings indicate that iron can potentiate enteric virus infectivity, posing a potential risk to human and animal health, particularly during pollution disasters such as that described here in Mariana, Brazil.


Assuntos
Adenovírus Humanos/crescimento & desenvolvimento , Vírus da Hepatite A/crescimento & desenvolvimento , Ferro/análise , Minerais/análise , Rios/virologia , Infecções por Adenovirus Humanos/virologia , Adenovírus Humanos/genética , Adenovírus Humanos/isolamento & purificação , Adenovírus Humanos/metabolismo , Brasil , Enterovirus/genética , Enterovirus/crescimento & desenvolvimento , Enterovirus/isolamento & purificação , Enterovirus/metabolismo , Monitoramento Ambiental , Hepatite A/virologia , Vírus da Hepatite A/genética , Vírus da Hepatite A/isolamento & purificação , Vírus da Hepatite A/metabolismo , Humanos , Ferro/metabolismo , Mineração , Rios/química , Poluição da Água
2.
Artigo em Inglês | MEDLINE | ID: mdl-30319992

RESUMO

Hepatitis A virus (HAV) is one of the most common agents causing acute liver disease worldwide. HAV has been increasingly reported as the cause of foodborne disease outbreaks. The standard method currently available for detection of the genome of HAV in vulnerable foodstuffs is by RT-qPCR (ISO 15216). Despite its usefulness in the investigation of foodborne viruses, the use of RT-qPCR in food virology has been shown to overestimate the quantity of infectious virus or to highly underestimate the effect of the treatment on virus inactivation. The gold standard methods currently used for evaluating the efficacy of inactivation treatments on the adapted strain of HAV (HM175/18f) are either the plaque assay or the end-point dilution assay (TCID50). However, both assays are labor-intensive and time-consuming. The aim of this study was to evaluate the use of the xCELLigence real-time cell analysis (RTCA) system for detecting the infectivity of the adapted strain of HAV. Kinetics of cell impedance showed that HAV induced a decrease in cell index (CI) correlated with the onset of HAV-induced cell death. In addition, the time to which the HAV-induced CI drop occurred was dependent on the viral concentration. An inverse linear relation could be established over a range of 5 log10 between the concentration of HAV and the time to reach 50% of CI decrease (TCI50), showing that the RTCA assay could be used as a titration method for HAV. In addition, the RTCA-based assay could be performed in less than 6 days instead of 12 to 14 days with the gold standard methods. Therefore, the RTCA-based titration method is a powerful and suitable tool for high-throughput screening of anti-viral treatments. Its usefulness in HAV inactivation studies will improve the assessment of viral risk in food virology, as controlling transmission of viruses through their removal from foodstuffs is also an important challenge in reducing the burden of viral foodborne illnesses.


Assuntos
Técnicas Citológicas/métodos , Impedância Elétrica , Microbiologia de Alimentos/métodos , Vírus da Hepatite A/crescimento & desenvolvimento , Vírus da Hepatite A/isolamento & purificação , Animais , Linhagem Celular , Sobrevivência Celular , Ensaios de Triagem em Larga Escala/métodos , Macaca mulatta , Fatores de Tempo , Carga Viral
3.
Food Environ Virol ; 10(3): 316-326, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29696605

RESUMO

The virological quality of surface marine and running water samples collected from Igoumenitsa gulf and Kalamas river (NW Greece) was assessed from October 2012 to September 2013. Sampling sites were exposed to different land and/or anthropogenic effects. Seawater samples were collected monthly from five sampling stations (new harbor, old harbor, wastewater treatment plant outlet, protected Natura area, Drepano beach). Viral targets included human adenoviruses (hAdVs), as index human viruses, while noroviruses (NoVs) and hepatitis A virus (HAV) were also studied. Kalamas river samples were collected seasonally, from three sampling stations (Soulopoulo, Dam, Sagiada-estuaries), while viral targets included also porcine adenoviruses (pAdVs) and bovine polyoma viruses (bPyVs), as additional index viruses. All water samples were analyzed for standard bacterial indicators, as well. Physicochemical and meteorological data were also collected. Based on the standard bacterial indices, both sea and river water samples did not exceed the limits set according to Directive 2006/7/EU. However, positive samples for hAdVs were found occasionally in all sampling sites in Igoumenitsa gulf (23.3%, 14/60) showing fecal contamination of human origin. Moreover, HAV was detected once, in the sampling site of the old port (at 510 GC/L). Most of the Kalamas water samples were found positive for hAdVs (58.3%, 7/12), while human noroviruses GI (NoVGI) (8.3%, 1/12) and GII (NoVGII) (16.7%, 2/12) were also detected. HAV, pAdVs, and bovine polyomaviruses (bPyVs) were not detected in any of the analyzed samples. No statistically significant correlations were found between classic bacterial indicators and viral targets, nor between viruses and meteorological data. Overall, the present study contributed to the collection of useful data for the biomonitoring of the region, and the assessment of the overall impact of anthropogenic activities. It provided also valuable information for the evaluation of the risk of waterborne viral infections and the protection of public health. It was the first virological study in the area and one of the few in Greece.


Assuntos
Água Doce/virologia , Água do Mar/virologia , Vírus/crescimento & desenvolvimento , Microbiologia da Água , Qualidade da Água , Adenoviridae/crescimento & desenvolvimento , Adenovírus Humanos/crescimento & desenvolvimento , Adenovirus Suínos/crescimento & desenvolvimento , Animais , Bovinos , Monitoramento Ambiental , Grécia , Vírus da Hepatite A/crescimento & desenvolvimento , Humanos , Norovirus/crescimento & desenvolvimento , Polyomavirus/crescimento & desenvolvimento , Suínos
4.
J Appl Microbiol ; 124(4): 965-976, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28833965

RESUMO

AIM: To assess the potential of a viability dye and an enzymatic reverse transcription quantitative PCR (RT-qPCR) pretreatment to discriminate between infectious and noninfectious enteric viruses. METHODS AND RESULTS: Enterovirus (EntV), norovirus (NoV) GII.4 and hepatitis A virus (HAV) were inactivated at 95°C for 10 min, and four methods were used to compare the efficiency of inactivation: (i) cell culture plaque assay for HAV and EntV, (ii) RT-qPCR alone, (iii) RT-qPCR assay preceded by RNase treatment, and (iv) pretreatment with a viability dye (reagent D (RD)) followed by RT-qPCR. In addition, heat-inactivated NoV was treated with RD coupled with surfactants to increase the efficiency of the viability dye. No treatment was able to completely discriminate infectious from noninfectious viruses. RD-RT-qPCR reduced more efficiently the detection of noninfectious viruses with little to no removal observed with RNase. RD-RT-qPCR method was the closest to cell culture assay. The combination of surfactants and RD did not show relevant improvements on the removal of inactivated viruses signal compared with viability RT-qPCR, with the exception of Triton X-100. CONCLUSION: The use of surfactant/RD-RT-qPCR, although not being able to completely remove the signal from noninfectious viral particles, yielded a better estimation of viral infectivity. SIGNIFICANCE AND IMPACT OF THE STUDY: Surfactant/RD-RT-qPCR may be an advantageous tool for a better detection of infectious viruses with potential significant impact in the risk assessment of the presence of enteric viruses.


Assuntos
Enterovirus/química , Vírus da Hepatite A/química , Norovirus/química , Reação em Cadeia da Polimerase em Tempo Real/métodos , Infecções por Caliciviridae/virologia , Enterovirus/genética , Enterovirus/crescimento & desenvolvimento , Enterovirus/isolamento & purificação , Infecções por Enterovirus/virologia , Hepatite A/virologia , Vírus da Hepatite A/genética , Vírus da Hepatite A/crescimento & desenvolvimento , Vírus da Hepatite A/fisiologia , Temperatura Alta , Humanos , Norovirus/genética , Norovirus/crescimento & desenvolvimento , Norovirus/fisiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ribonucleases/química , Inativação de Vírus
5.
Food Environ Virol ; 8(2): 125-32, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27008344

RESUMO

Cinnamaldehyde (CNMA), an organic compound that gives cinnamon its flavor and odor, was investigated for its virucidal activity on norovirus surrogates, murine norovirus (MNV) and feline calicivirus (FCV), and hepatitis A virus (HAV). Initially, different concentrations of CNMA (0.1, 0.5 and 1 %) were individually mixed with each virus at titers of ca. 6-7 log10 TCID50/ml and incubated 2 h at 4 and 37 °C. CNMA was effective in reducing the titers of norovirus surrogates in a dose-dependent manner after 2 h at 37 °C, while HAV titers were reduced by 1 log10 after treatment with 1 % of CNMA. When incubation time was extended, HAV titers were reduced by 3.4 and 2.7 log10 after overnight incubation at 37 °C with 1 and 0.5 % of CNMA, respectively. Moreover, this paper analyzed, for the first time, the antiviral activity of adding an active electrospun interlayer based on zein and CNMA to a polyhydroxybutyrate packaging material (PHB) in a multilayer form. Biodegradable multilayer systems prepared with 2.60 mg/cm(2) (~9.7 %) of CNMA completely inactivated FCV according to ISO 22196:2011, while MNV titers were reduced by 2.75 log10. When the developed multilayer films were evaluated after one month of preparation or at 25 °C, the antiviral activity was reduced as compared to freshly prepared multilayer films evaluated at 37 °C. The results show the excellent potential of this system for food contact applications as well as for active packaging technologies in order to maintain or extend food quality and safety.


Assuntos
Acroleína/análogos & derivados , Calicivirus Felino/efeitos dos fármacos , Embalagem de Alimentos/instrumentação , Vírus da Hepatite A/efeitos dos fármacos , Norovirus/efeitos dos fármacos , Acroleína/farmacologia , Animais , Calicivirus Felino/crescimento & desenvolvimento , Gatos , Desinfetantes/farmacologia , Contaminação de Alimentos/prevenção & controle , Vírus da Hepatite A/crescimento & desenvolvimento , Humanos , Camundongos , Norovirus/crescimento & desenvolvimento , Papel , Inativação de Vírus/efeitos dos fármacos
6.
Int J Food Microbiol ; 211: 73-8, 2015 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-26184763

RESUMO

In this study, the effects of 10-300 mWs/cm(2) of ultraviolet radiation (UV-C) at 260 nm were investigated for the inactivation of two foodborne viruses: murine norovirus-1 (MNV-1; a human norovirus [NoV] surrogate) and hepatitis A virus (HAV). We used an experimentally contaminated stainless steel surface, a common food-contact surface, to examine the effects of low doses of UV-C radiation on MNV-1 and HAV titers. The modified Gompertz equation was used to generate non-linear survival curves and calculate dR-values as the UV-C dose of 90% reduction for MNV-1 (R(2)=0.95, RMSE=0.038) and HAV (R(2)=0.97, RMSE=0.016). Total MNV-1 and HAV titers significantly decreased (p<0.05) with higher doses of UV-C. MNV-1 and HAV were reduced to 0.0-4.4 and 0.0-2.6 log10PFU/ml, respectively, on the stainless steel surfaces by low-dose UV-C treatment. The dR-value, 33.3 mWs/cm(2) for MNV-1 was significantly (p<0.05) lower than 55.4 mWs/cm(2) of HAV. Therefore, the present study shows that HAV is more resistant to UV-C radiation than MNV-1. These data suggest that low doses of UV-C light on food contact surfaces could be effective to inactivate human NoV and HAV in restaurant, institutional, and industrial kitchens and facilities.


Assuntos
Vírus da Hepatite A/efeitos da radiação , Norovirus/efeitos da radiação , Aço Inoxidável/análise , Esterilização/métodos , Animais , Manipulação de Alimentos/instrumentação , Vírus da Hepatite A/crescimento & desenvolvimento , Humanos , Camundongos , Norovirus/crescimento & desenvolvimento , Células RAW 264.7 , Raios Ultravioleta
7.
Food Environ Virol ; 7(4): 366-73, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26143492

RESUMO

Hibiscus sabdariffa extract is known to have antioxidant, anti-diabetic, and antimicrobial properties. However, their effects against foodborne viruses are currently unknown. The objective of this study was to determine the antiviral effects of aqueous extracts of H. sabdariffa against human norovirus surrogates (feline calicivirus (FCV-F9) and murine norovirus (MNV-1)) and hepatitis A virus (HAV) at 37 °C over 24 h. Individual viruses (~5 log PFU/ml) were incubated with 40 or 100 mg/ml of aqueous hibiscus extract (HE; pH 3.6), protocatechuic acid (PCA; 3 or 6 mg/ml, pH 3.6), ferulic acid (FA; 0.5 or 1 mg/ml; pH 4.0), malic acid (10 mM; pH 3.0), or phosphate buffered saline (pH 7.2 as control) at 37 °C over 24 h. Each treatment was replicated thrice and plaque assayed in duplicate. FCV-F9 titers were reduced to undetectable levels after 15 min with both 40 and 100 mg/ml HE. MNV-1 was reduced by 1.77 ± 0.10 and 1.88 ± 0.12 log PFU/ml after 6 h with 40 and 100 mg/ml HE, respectively, and to undetectable levels after 24 h by both concentrations. HAV was reduced to undetectable levels by both HE concentrations after 24 h. PCA at 3 mg/ml reduced FCV-F9 titers to undetectable levels after 6 h, MNV-1 by 0.53 ± 0.01 log PFU/ml after 6 h, and caused no significant change in HAV titers. FA reduced FCV-F9 to undetectable levels after 3 h and MNV-1 and HAV after 24 h. Transmission electron microscopy showed no conclusive results. The findings suggest that H. sabdariffa extracts have potential to prevent foodborne viral transmission.


Assuntos
Antivirais/metabolismo , Calicivirus Felino/fisiologia , Aditivos Alimentares/metabolismo , Hibiscus/química , Modelos Biológicos , Norovirus/fisiologia , Extratos Vegetais/metabolismo , Animais , Antivirais/química , Bebidas , Infecções por Caliciviridae/prevenção & controle , Infecções por Caliciviridae/virologia , Calicivirus Felino/crescimento & desenvolvimento , Calicivirus Felino/isolamento & purificação , Calicivirus Felino/ultraestrutura , Linhagem Celular , Flores/química , Aditivos Alimentares/química , Doenças Transmitidas por Alimentos/prevenção & controle , Doenças Transmitidas por Alimentos/virologia , Alimento Funcional , Gastroenterite/prevenção & controle , Gastroenterite/virologia , Hepatite A/prevenção & controle , Hepatite A/virologia , Vírus da Hepatite A/crescimento & desenvolvimento , Vírus da Hepatite A/isolamento & purificação , Vírus da Hepatite A/fisiologia , Vírus da Hepatite A/ultraestrutura , Humanos , Microscopia Eletrônica de Transmissão , Norovirus/crescimento & desenvolvimento , Norovirus/isolamento & purificação , Norovirus/ultraestrutura , Extratos Vegetais/química , Fenômenos Fisiológicos Virais
8.
J Food Prot ; 78(8): 1597-617, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26219377

RESUMO

Foodborne viruses, in particular human norovirus and hepatitis A virus, are the most common causes of food-associated infections and foodborne illness outbreaks around the world. Since it is currently not possible to cultivate human noroviruses and the wild-type strain of hepatitis A virus in vitro, the use of a variety of viral surrogates is essential to determine appropriate thermal processing conditions to reduce the risk associated with their contamination of food. Therefore, the objectives of this review are to (i) present pertinent characteristics of enteric foodborne viruses and their viral surrogates, (ii) discuss the viral surrogates currently used in thermal inactivation studies and their significance and value, (iii) summarize available data on thermal inactivation kinetics of enteric viruses, (iv) discuss factors affecting the efficacy of thermal treatment, (v) discuss suggested mechanisms of thermal inactivation, and (vi) provide insights on foodborne enteric viruses and viral surrogates for future studies and industrial applications. The overall goal of this review is to contribute to the development of appropriate thermal processing protocols to ensure safe food for human consumption.


Assuntos
Enterovirus/crescimento & desenvolvimento , Contaminação de Alimentos/análise , Doenças Transmitidas por Alimentos/prevenção & controle , Temperatura Alta , Inativação de Vírus , Laticínios/virologia , Enterovirus/isolamento & purificação , Manipulação de Alimentos , Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/virologia , Frutas/virologia , Vírus da Hepatite A/crescimento & desenvolvimento , Vírus da Hepatite A/isolamento & purificação , Humanos , Produtos da Carne/virologia , Norovirus/crescimento & desenvolvimento , Norovirus/isolamento & purificação , Alimentos Marinhos/virologia , Verduras/virologia
9.
J Appl Microbiol ; 119(3): 834-44, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26184406

RESUMO

AIMS: Epidemiological evidence suggests that hepatitis A virus (HAV) is the most common pathogen transmitted by bivalve molluscs such as clams, cockles, mussels and oysters. This study aimed to generate thermal inactivation kinetics for HAV as a first step to design adequate thermal processes to control clam-associated HAV outbreaks. METHODS AND RESULTS: Survivor curves and thermal death curves were generated for different treatment times (0-6 min) at different temperatures (50-72°C) and Weibull and first-order models were compared. D-values for HAV ranged from 47·37 ± 1·23 to 1·55 ± 0·12 min for the first-order model and 64·43 ± 3·47 to 1·25 ± 0·45 min for the Weibull model at temperatures from 50 to 72°C. z-Values for HAV in clams were 12·97 ± 0·59°C and 14·83 ± 0·0·28°C using the Weibull and first-order model respectively. The calculated activation energies for the first-order and Weibull model were 145 and 170 kJ mole(-1) respectively. CONCLUSION: The Weibull model described the thermal inactivation behaviour of HAV better than the first-order model. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides novel and precise information on thermal inactivation kinetics of HAV in homogenized clams. This will enable reliable thermal process calculations for HAV inactivation in clams and closely related seafood.


Assuntos
Vírus da Hepatite A/química , Vírus da Hepatite A/crescimento & desenvolvimento , Produtos da Carne/microbiologia , Mercenaria/virologia , Frutos do Mar/virologia , Animais , Temperatura Alta , Cinética , Temperatura , Inativação de Vírus
10.
Food Microbiol ; 49: 220-5, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25846934

RESUMO

Enteric virus depuration from shellfish is a complex biological process that may be influenced by biological properties of the mollusc and/or virus species. On the basis of previous experimental data, a mathematical model was developed to characterize the kinetics of viral elimination during the depuration process. The experimental data consisted on twenty depuration trials, each with 60 kg of Manila clams (Venerupis philippinarum) and mediterranean mussels (Mytilus galloprovincialis) previously subjected to bioaccumulation with HAV or MNV-1 (as a surrogate for human norovirus), that were performed in an experimental depuration system during 7 days. It was observed that although viral loads decay along depuration, a residual viral load remains at the end of the process suggesting a decomposition of viral load in a diluted load (susceptible of depuration) and a non-diluted load (unavailable to depurate). The model yielded a general equation, which can predict the viral load at any depuration time knowing the specific filtration rate, dependent on the bivalve species, and specific viral properties. The mathematical model can be combined with quantitative risk assessment calculations to determine the safety of the depurated shellfish, which can be very helpful not only for shellfish producers but also to public health authorities.


Assuntos
Bivalves/virologia , Vírus da Hepatite A/crescimento & desenvolvimento , Modelos Teóricos , Mytilus/virologia , Norovirus/crescimento & desenvolvimento , Frutos do Mar/virologia , Animais , Qualidade de Produtos para o Consumidor , Manipulação de Alimentos , Vírus da Hepatite A/química , Vírus da Hepatite A/isolamento & purificação , Cinética , Norovirus/química , Norovirus/isolamento & purificação
11.
Food Environ Virol ; 7(1): 76-85, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25344058

RESUMO

Consumption of raw or insufficiently cooked mussels contaminated with hepatitis A virus (HAV) is a major cause of infection to humans. The origin of mussels commonly used for the preparation of marinated seafood salads is often unknown, since different producers worldwide undergo a precooking treatment at the original collection site with methods and parameters not always indicated. These treatments could be insufficient for the inactivation of HAV, which is characterized by a high temperature resistance. Both high hydrostatic pressure (HHP) and marinade treatments have been shown to affect HAV vitality. In this study, two treatments (HHP and marinating) were combined in order to assess a potential synergistic effect on the virus vitality. A kinetic test was conducted by subjecting the experimentally-contaminated mussels (HAV titre: 10(6)/ml TCID50) to marinating, and to different HHP treatment (4,000; 5,000; and 6,000 bar for 1, 5, and 9 min). Virus post-treatment vitality was assessed by its ability to grow on cell cultures and by quantitative real-time RT-PCR to evaluate virus resistance under such conditions. Marinating treatment alone (final pH 4.3, and NaCl 2 %) did not inactivate the virus. On the other hand, the use of HHP treatment alone on non-marinated HAV-contaminated mussels was effective only above 5,000 bar for 5 min. The results of the present study elucidate the synergistic effect of a combination between marination and HHP treatments on the inactivation of the virus.


Assuntos
Bivalves/virologia , Conservação de Alimentos/métodos , Vírus da Hepatite A/química , Frutos do Mar/virologia , Animais , Contaminação de Alimentos/análise , Conservação de Alimentos/instrumentação , Vírus da Hepatite A/crescimento & desenvolvimento , Temperatura Alta , Pressão Hidrostática
12.
Food Microbiol ; 42: 212-7, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24929739

RESUMO

Human noroviruses and hepatitis A virus (HAV) are considered as epidemiologically significant causes of foodborne disease. Therefore, studies are needed to bridge existing data gaps and determine appropriate parameters for thermal inactivation of human noroviruses and HAV. The objectives of this research were to compare the thermal inactivation kinetics of human norovirus surrogates (murine norovirus (MNV-1), and feline calicivirus (FCV-F9)) and HAV in buffered medium (2-ml vials), compare first-order and Weibull models to describe the data, calculate Arrhenius activation energy for each model, and evaluate model efficiency using selected statistical criteria. The D-values calculated from the first-order model (50-72 °C) ranged from 0.21-19.75 min for FCV-F9, 0.25-36.28 min for MNV-1, and 0.88-56.22 min for HAV. Using the Weibull model, the tD = 1 (time to destroy 1 log) for FCV-F9, MNV-1 and HAV at the same temperatures ranged from 0.10-13.27, 0.09-26.78, and 1.03-39.91 min, respectively. The z-values for FCV-F9, MNV-1, and HAV were 9.66 °C, 9.16 °C, and 14.50 °C, respectively, using the Weibull model. For the first order model, z-values were 9.36 °C, 9.32 °C, and 12.49 °C for FCV-F9, MNV-1, and HAV, respectively. For the Weibull model, estimated activation energies for FCV-F9, MNV-1, and HAV were 225, 278, and 182 kJ/mol, respectively, while the calculated activation energies for the first order model were 195, 202, and 171 kJ/mol, respectively. Knowledge of the thermal inactivation kinetics of norovirus surrogates and HAV will allow the development of processes that produce safer food products and improve consumer safety.


Assuntos
Calicivirus Felino/crescimento & desenvolvimento , Meios de Cultura/química , Vírus da Hepatite A/crescimento & desenvolvimento , Norovirus/crescimento & desenvolvimento , Esterilização/métodos , Inativação de Vírus , Animais , Calicivirus Felino/química , Vírus da Hepatite A/química , Humanos , Cinética , Norovirus/química , Norovirus/classificação , Esterilização/instrumentação , Temperatura
13.
Appl Environ Microbiol ; 80(10): 3191-7, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24632250

RESUMO

Hepatitis A virus (HAV) is a food-borne enteric virus responsible for outbreaks of hepatitis associated with shellfish consumption. The objectives of this study were to determine the thermal inactivation behavior of HAV in blue mussels, to compare the first-order and Weibull models to describe the data, to calculate Arrhenius activation energy for each model, and to evaluate model efficiency by using selected statistical criteria. The times required to reduce the population by 1 log cycle (D-values) calculated from the first-order model (50 to 72°C) ranged from 1.07 to 54.17 min for HAV. Using the Weibull model, the times required to destroy 1 log unit (tD = 1) of HAV at the same temperatures were 1.57 to 37.91 min. At 72°C, the treatment times required to achieve a 6-log reduction were 7.49 min for the first-order model and 8.47 min for the Weibull model. The z-values (changes in temperature required for a 90% change in the log D-values) calculated for HAV were 15.88 ± 3.97°C (R(2), 0.94) with the Weibull model and 12.97 ± 0.59°C (R(2), 0.93) with the first-order model. The calculated activation energies for the first-order model and the Weibull model were 165 and 153 kJ/mol, respectively. The results revealed that the Weibull model was more appropriate for representing the thermal inactivation behavior of HAV in blue mussels. Correct understanding of the thermal inactivation behavior of HAV could allow precise determination of the thermal process conditions to prevent food-borne viral outbreaks associated with the consumption of contaminated mussels.


Assuntos
Culinária/métodos , Contaminação de Alimentos/análise , Vírus da Hepatite A/crescimento & desenvolvimento , Mytilus edulis/virologia , Frutos do Mar/virologia , Inativação de Vírus , Animais , Vírus da Hepatite A/química , Vírus da Hepatite A/fisiologia , Temperatura Alta , Cinética
14.
Food Microbiol ; 39: 103-7, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24387859

RESUMO

The efficacy and dynamic of depuration for the removal of hepatitis A virus (HAV) contamination were evaluated under experimental conditions using Manila clams previously subjected to bioaccumulation with this virus. Five independent trials were assayed in a closed experimental system with a total volume of approximately 1750 l, using clam batches of 60 Kg. The reverse transcriptase-real time PCR (RT-qPCR) technique was utilized for viral quantification. Infectivity assays were conducted at the end of depuration. Although the final viral loads in shellfish after 7 days remained relatively high and still infectious, an average reduction in HAV levels of 1.44 log units (approx. 93.1%) was observed. This reduction showed a two-phase removal kinetic, with an initial rapid reduction of viruses during the first 72 h of depuration, with a 0.6 log units (69%) of average decrease in HAV RNA copies/g digestive tissue, and a subsequent stabilization with a slower depuration rate in the remaining days.


Assuntos
Bivalves/virologia , Contaminação de Alimentos/análise , Vírus da Hepatite A/crescimento & desenvolvimento , Frutos do Mar/virologia , Animais , Descontaminação , Contaminação de Alimentos/prevenção & controle , Vírus da Hepatite A/química , Vírus da Hepatite A/genética , Vírus da Hepatite A/isolamento & purificação , Cinética
15.
Mol Gen Mikrobiol Virusol ; (3): 12-21, 2013.
Artigo em Russo | MEDLINE | ID: mdl-24364140

RESUMO

The analysis of recently published data on hepatitis A virus (HAV) genome clinical features, molecular diagnostic value and cell culture propagation are reviewed. The growing need in the study of the genetic diversity of HAV isolates and the search of its possible new antigenic variants are underlined. The results of the cultivation of different HAV strains are analyzed for possible application in vaccine and diagnostic kit production.


Assuntos
Variação Genética , Genoma Viral , Vírus da Hepatite A , Hepatite A , Kit de Reagentes para Diagnóstico , Animais , Hepatite A/diagnóstico , Hepatite A/genética , Hepatite A/metabolismo , Antígenos da Hepatite A/genética , Antígenos da Hepatite A/metabolismo , Vírus da Hepatite A/genética , Vírus da Hepatite A/crescimento & desenvolvimento , Vírus da Hepatite A/metabolismo , Humanos
16.
Appl Environ Microbiol ; 79(22): 7021-7, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24014537

RESUMO

Human norovirus (huNoV) and hepatitis A virus (HAV) have been involved in several produce-associated outbreaks and identified as major food-borne viral etiologies. In this study, the survival of huNoV surrogates (murine norovirus [MNV] and Tulane virus [TV]) and HAV was investigated on alfalfa seeds during storage and postgermination. Alfalfa seeds were inoculated with MNV, TV, or HAV with titers of 6.46 ± 0.06 log PFU/g, 3.87 ± 0.38 log PFU/g, or 7.01 ± 0.07 log 50% tissue culture infectious doses (TCID50)/g, respectively. Inoculated seeds were stored for up to 50 days at 22°C and sampled during that storage period on days 0, 2, 5, 10, and 15. Following storage, virus presence was monitored over a 1-week germination period. Viruses remained infectious after 50 days, with titers of 1.61 ± 0.19 log PFU/g, 0.85 ± 0.21 log PFU/g, and 3.43 ± 0.21 log TCID50/g for MNV, TV, and HAV, respectively. HAV demonstrated greater persistence than MNV and TV, without a statistically significant reduction over 20 days (<1 log TCID50/g); however, relatively high levels of genomic copies of all viruses persisted over the testing time period. Low titers of viruses were found on sprouts and were located in all tissues as well as in sprout-spent water sampled on days 1, 3, and 6 following seed planting. Results revealed the persistence of viruses in seeds for a prolonged period of time, and perhaps of greater importance these data suggest the ease of which virus may transfer from seeds to sprouts and spent water during germination. These findings highlight the importance of sanitation and prevention procedures before and during germination.


Assuntos
Contaminação de Alimentos/análise , Vírus da Hepatite A/crescimento & desenvolvimento , Norovirus/crescimento & desenvolvimento , Sementes/virologia , Animais , Manipulação de Alimentos/métodos , Microbiologia de Alimentos , Armazenamento de Alimentos , Doenças Transmitidas por Alimentos/virologia , Germinação , Vírus da Hepatite A/isolamento & purificação , Medicago sativa/virologia , Camundongos , Norovirus/isolamento & purificação
17.
J Food Sci ; 78(9): M1412-5, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23931146

RESUMO

Red ginseng has a variety of bioactive functions and is widely used as an oriental medicinal herb and food ingredient. The aim of this study was to investigate the antiviral effect of red ginseng extract and ginsenosides against hepatitis A virus (HAV). To examine the antiviral effect against HAV, 0 to 10 µg/mL of red ginseng and purified ginsenoside Rb1 and Rg1 were pre-treated or co-treated on FRhK-4 cells. The HAV titer decreased significantly in all groups pretreated with red ginseng or purified ginsenosides. The reduction of HAV was significant in FRhK-4 cells pre-treated only with red ginseng. Our results showed that red ginseng and ginsenoside Rg1 and Rb1 could decrease HAV titers.


Assuntos
Antivirais/farmacologia , Ginsenosídeos/farmacologia , Vírus da Hepatite A/efeitos dos fármacos , Panax/química , Extratos Vegetais/farmacologia , Animais , Linhagem Celular , Contaminação de Alimentos/prevenção & controle , Microbiologia de Alimentos , Vírus da Hepatite A/crescimento & desenvolvimento , Macaca mulatta , Plantas Medicinais/química
18.
Food Microbiol ; 35(1): 1-9, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23628607

RESUMO

Food-borne viruses such as human Noroviruses (NoVs), hepatitis A virus (HAV), Rotaviruses (RoVs) are a public health concern worldwide. Biochemical substances, which occur naturally in plants, animals or microorganisms, might possess considerable antimicrobial properties. In this study, the reported effects of biochemical substances on food-borne viruses are reviewed. The biochemical substances are grouped into several categories including (i) polyphenols and proanthocyanins, (ii) saponin, (iii) polysaccharides, (iv) organic acids, (v) proteins and polypeptides, (vi) essential oils. Although not fully understood, the mechanism of action for the antiviral activity of the natural compounds is presented. Generally, it is thought to be the prevention of the viral attachment to host cells, either by causing damage on the viral capsids or change of the receptors on the cell membranes. It is recommended that further studies are undertaken not only on the wide-range screening for novel antiviral substances, but also on the mechanism in-depth as well as the exploration for their potential application in controlling virus contamination in foods or food processing.


Assuntos
Antivirais/farmacologia , Produtos Biológicos/farmacologia , Contaminação de Alimentos/prevenção & controle , Vírus da Hepatite A/efeitos dos fármacos , Norovirus/efeitos dos fármacos , Rotavirus/efeitos dos fármacos , Antocianinas/farmacologia , Microbiologia de Alimentos/métodos , Vírus da Hepatite A/crescimento & desenvolvimento , Norovirus/crescimento & desenvolvimento , Óleos Voláteis/farmacologia , Polifenóis/farmacologia , Polissacarídeos/farmacologia , Rotavirus/crescimento & desenvolvimento , Saponinas/farmacologia
19.
Nature ; 496(7445): 367-71, 2013 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-23542590

RESUMO

Animal viruses are broadly categorized structurally by the presence or absence of an envelope composed of a lipid-bilayer membrane, attributes that profoundly affect stability, transmission and immune recognition. Among those lacking an envelope, the Picornaviridae are a large and diverse family of positive-strand RNA viruses that includes hepatitis A virus (HAV), an ancient human pathogen that remains a common cause of enterically transmitted hepatitis. HAV infects in a stealth-like manner and replicates efficiently in the liver. Virus-specific antibodies appear only after 3-4 weeks of infection, and typically herald its resolution. Although unexplained mechanistically, both anti-HAV antibody and inactivated whole-virus vaccines prevent disease when administered as late as 2 weeks after exposure, when virus replication is well established in the liver. Here we show that HAV released from cells is cloaked in host-derived membranes, thereby protecting the virion from antibody-mediated neutralization. These enveloped viruses ('eHAV') resemble exosomes, small vesicles that are increasingly recognized to be important in intercellular communications. They are fully infectious, sensitive to extraction with chloroform, and circulate in the blood of infected humans. Their biogenesis is dependent on host proteins associated with endosomal-sorting complexes required for transport (ESCRT), namely VPS4B and ALIX. Whereas the hijacking of membranes by HAV facilitates escape from neutralizing antibodies and probably promotes virus spread within the liver, anti-capsid antibodies restrict replication after infection with eHAV, suggesting a possible explanation for prophylaxis after exposure. Membrane hijacking by HAV blurs the classic distinction between 'enveloped' and 'non-enveloped' viruses and has broad implications for mechanisms of viral egress from infected cells as well as host immune responses.


Assuntos
Membrana Celular/metabolismo , Vírus da Hepatite A/metabolismo , Interações Hospedeiro-Patógeno , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/uso terapêutico , Linhagem Celular , Chlorocebus aethiops , Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Hepatite A/sangue , Hepatite A/imunologia , Hepatite A/prevenção & controle , Hepatite A/virologia , Vírus da Hepatite A/química , Vírus da Hepatite A/crescimento & desenvolvimento , Vírus da Hepatite A/imunologia , Humanos , Fígado/virologia , Macaca mulatta , Dados de Sequência Molecular , Testes de Neutralização , Pan troglodytes , Proteínas do Envelope Viral
20.
Food Environ Virol ; 5(1): 24-34, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23412715

RESUMO

Root uptake of enteric pathogens and subsequent internalization has been a produce safety concern and is being investigated as a potential route of pre-harvest contamination. The objective of this study was to determine the ability of hepatitis A virus (HAV) and the human norovirus surrogate, murine norovirus (MNV), to internalize in spinach and green onions through root uptake in both soil and hydroponic systems. HAV or MNV was inoculated into soil matrices or into two hydroponic systems, floating and nutrient film technique systems. Viruses present within spinach and green onions were detected by RT-qPCR or infectivity assays after inactivating externally present viruses with Virkon(®). HAV and MNV were not detected in green onion plants grown up to 20 days and HAV was detected in only 1 of 64 spinach plants grown in contaminated soil substrate systems up to 20 days. Compared to soil systems, a drastic difference in virus internalization was observed in hydroponic systems; HAV or pressure-treated HAV and MNV were internalized up to 4 log RT-qPCR units and internalized MNV was shown to remain infectious. Understanding the interactions of human enteric viruses on produce can aid in the elucidation of the mechanisms of attachment and internalization, and aid in understanding risks associated with contamination events.


Assuntos
Contaminação de Alimentos/análise , Cebolas/virologia , Spinacia oleracea/virologia , Enterovirus/crescimento & desenvolvimento , Enterovirus/isolamento & purificação , Enterovirus/patogenicidade , Microbiologia de Alimentos , Vírus da Hepatite A/crescimento & desenvolvimento , Vírus da Hepatite A/isolamento & purificação , Vírus da Hepatite A/patogenicidade , Hidroponia , Norovirus/crescimento & desenvolvimento , Norovirus/isolamento & purificação , Norovirus/patogenicidade , Raízes de Plantas/virologia , Reação em Cadeia da Polimerase , Microbiologia do Solo
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