Virus inactivation

Animal by-products (ABP) Category 3 includes hatchery waste, and also slaughterhouse waste and manure, aimed for use in biogas production. In order to be used as fertilisers, they must be sanitised to reduce pathogenic microorganisms. The initial European regulations regarding processing standards for ABP intended for use in e.g. biogas plants (EC No. 1774/2002) stipulated thermal treatment at 70°C for 60 min. A subsequent amendment (EC No. 208/2006) stated that a validated treatment process may be used if it can show a reduction in thermo-resistant viruses of at least 3 log10, whenever deamed a risk. Thermal treatments of biogas substrate at 70°C and at 55°C, using porcine parvovirus and swine vesicular disease virus, were performed. As a chemical sanitisation process regarding hatchery waste, ammonia inactivation was tested using the highly pathogenic avian influenza virus H7N1 and the low pathogenic avian influenza virus H5N3. Models for other avian pathogenic ssRNA viruses were bovine parainfluenza virus 3, feline calicivirus and feline coronavirus. As possible indicators for monitoring virus inactivation, bacteriophages MS2, ΦX174, and 28b were evaluated. Thermal treatment at 70°C for 60 min inactivated porcine parvovirus by 2.6 log10, while phage 28b was unaffected. Swine vesicular disease virus was undetectable after 30 min. Using too thermostable viruses as models for sufficient virus reduction in thermal treatments regarding Category 3 ABP materials and manure intended for biogas or composting plants, according to EU regulations, would make demands on other time-temperature combinations very strict. All viruses tested were efficiently inactivated by ammonia treatment in hatchery waste, while phage ΦX174 proved too conservative to be used as indicator. Using phage MS2 as a stable indicator to monitor a 3 log10 reduction of ssRNA virus showed that addition of 0.5% w/w ammonia is required, followed by storage for at least 31 h at ≥14°C. In case of an outbreak of e.g. avian influenza, storage for two days at the same conditions was estimated

Virus inactivation - evaluation of treatment processes for food and biowaste

Animal by-products and manure contain valuable plant nutrients that could be recycled onto arable land, as fertiliser. If these materials contain pathogenic microorganisms, such as viruses, transmission to domestic animals, wildlife and the food chain could occur. Virus contamination of food may further occur during all production phases, from slaughter to packaging and distribution. To reduce virus hazards, control measures such as physical and chemical treatments could be applied. As many important food-borne viruses are non-culturable, model viruses are often used to evaluate the effect of virus inactivation methods. As models for swine hepatitis E virus (HEV) in food treatments, feline calicivirus, murine norovirus and bacteriophages were evaluated. MS2 and ø6 were used as models for highly pathogenic avian influenza virus (HPAIV) in ammonia inactivation and composting of animal by-products, respectively. In laboratory scale, controlling the factors considered to be the most important for virus inactivation, reduction of relevant and model viruses was assessed as a function of these factors. Recommendations regarding continuously measurable process conditions that should be kept over a certain time to reach sufficient viral reductions could be given, both for normal conditions and in an out-break situation. Bacteriophages could further be used as potential indicators for verification or validation in pilot or full scale processes. Regimes to assure a 3 log10 reduction for Category 3 materials (2011/142/EC) for ammonia and heat treatment were determined. Further protocols based on pH and temperature to be kept during a certain time for management of HPAIV in outbreak situations were provided based on statistical evaluations of the laboratory results. In high pressure treatment of pork products, pressure and time were defined as critical control points for feline calicivirus and murine norovirus, used as models for HEV. MS2 and ø6 were successfully used for verification of ammonia treatment and composting, respectively, in larger scale. In food treatments, MS2 was the most conservative indicator of noro and calicivirus inactivation in high pressure and intense light pulse treatments, and øX174 in lactic acid treatments, with potential as models for these types of viruses for verification in production scale

Swine influenza viruses isolated in 1983, 2002 and 2009 in Sweden exemplify different lineages

Swine influenza virus isolates originating from outbreaks in Sweden from 1983, 2002 and 2009 were subjected to nucleotide sequencing and phylogenetic analysis. The aim of the studies was to obtain an overview on their potential relatedness as well as to provide data for broader scale studies on swine influenza epidemiology. Nonetheless, analyzing archive isolates is justified by the efforts directed to the comprehension of the appearance of pandemic H1N1 influenza virus. Interestingly, this study illustrates the evolution of swine influenza viruses in Europe, because the earliest isolate belonged to 'classical' swine H1N1, the subsequent ones to Eurasian 'avian-like' swine H1N1 and reassortant 'avian-like' swine H1N2 lineages, respectively. The latter two showed close genetic relatedness regarding their PB2, HA, NP, and NS genes, suggesting common ancestry. The study substantiates the importance of molecular surveillance for swine influenza viruses

Vilket inflytande har den äldre över sin tillvaro vid hjälp- och stödinsatser

Validerat; 20101217 (root

Inactivation of viruses and bacteriophages as models for swine hepatitis E virus in food matrices

Hepatitis E virus has been recognised as a food-borne virus hazard in pork products, due to its zoonotic properties. This risk can be reduced by adequate treatment of the food to inactivate food-borne viruses. We used a spectrum of viruses and bacteriophages to evaluate the effect of three food treatments: high pressure processing (HPP), lactic acid (LA) and intense light pulse (ILP) treatments. On swine liver at 400 MPa for 10 min, HPP gave log(10) reductions of ae4.2, ae5.0 and 3.4 for feline calicivirus (FCV) 2280, FCV wildtype (wt) and murine norovirus 1 (MNV 1), respectively. Escherichia coli coliphage I center dot X174 displayed a lower reduction of 1.1, while Escherichia coli coliphage MS2 was unaffected. For ham at 600 MPa, the corresponding reductions were 4.1, 4.4, 2.9, 1.7 and 1.3 log(10). LA treatment at 2.2 M gave log(10) reductions in the viral spectrum of 0.29-2.1 for swine liver and 0.87-3.1 for ham, with I center dot X174 and MNV 1, respectively, as the most stable microorganisms. The ILP treatment gave log(10) reductions of 1.6-2.8 for swine liver, 0.97-2.2 for ham and 1.3-2.3 for sausage, at 15-60 J cm(-2), with MS2 as the most stable microorganism. The HPP treatment gave significantly (p < 0.05) greater virus reduction on swine liver than ham for the viruses at equivalent pressure/time combinations. For ILP treatment, reductions on swine liver were significantly (p < 0.05) greater than on ham for all microorganisms. The results presented here could be used in assessments of different strategies to protect consumers against virus contamination and in advice to food producers. Conservative model indicators for the pathogenic viruses could be suggested

Cross-Protection of Chicken Immunoglobulin Y Antibodies against H5N1 and H1N1 Viruses Passively Administered in Mice

Influenza viruses remain a major threat to global health due to their ability to undergo change through antigenic drift and antigenic shift. We postulated that avian IgY antibodies represent a low-cost, effective, and well-tolerated approach that can easily be scaled up to produce enormous quantities of protective antibodies. These IgY antibodies can be administered passively in humans (orally and intranasally) and can be used quickly and safely to help in the fight against an influenza pandemic. In this study, we raised IgY antibodies against H1N1, H3N2, and H5N1 influenza viruses. We demonstrated that, using whole inactivated viruses alone and in combination to immunize hens, we were able to induce a high level of anti-influenza virus IgY in the sera and eggs, which lasted for at least 2 months after two immunizations. Furthermore, we found that by use of in vitro assays to test for the ability of IgY to inhibit hemagglutination (HI test) and virus infectivity (serum neutralization test), IgYs inhibited the homologous as well as in some cases heterologous clades and strains of viruses. Using an in vivo mouse model system, we found that, when administered intranasally 1 h prior to infection, IgY to H5N1 protected 100% of the mice against lethal challenge with H5N1. Of particular interest was the finding that IgY to H5N1 cross-protected against A/Puerto Rico/8/34 (H1N1) both in vitro and in vivo. Based on our results, we conclude that anti-influenza virus IgY can be used to help prevent influenza virus infection

Cross-Protection of Chicken Immunoglobulin Y Antibodies against H5N1 and H1N1 Viruses Passively Administered in Mice▿

Influenza viruses remain a major threat to global health due to their ability to undergo change through antigenic drift and antigenic shift. We postulated that avian IgY antibodies represent a low-cost, effective, and well-tolerated approach that can easily be scaled up to produce enormous quantities of protective antibodies. These IgY antibodies can be administered passively in humans (orally and intranasally) and can be used quickly and safely to help in the fight against an influenza pandemic. In this study, we raised IgY antibodies against H1N1, H3N2, and H5N1 influenza viruses. We demonstrated that, using whole inactivated viruses alone and in combination to immunize hens, we were able to induce a high level of anti-influenza virus IgY in the sera and eggs, which lasted for at least 2 months after two immunizations. Furthermore, we found that by use of in vitro assays to test for the ability of IgY to inhibit hemagglutination (HI test) and virus infectivity (serum neutralization test), IgYs inhibited the homologous as well as in some cases heterologous clades and strains of viruses. Using an in vivo mouse model system, we found that, when administered intranasally 1 h prior to infection, IgY to H5N1 protected 100% of the mice against lethal challenge with H5N1. Of particular interest was the finding that IgY to H5N1 cross-protected against A/Puerto Rico/8/34 (H1N1) both in vitro and in vivo. Based on our results, we conclude that anti-influenza virus IgY can be used to help prevent influenza virus infection