An inactivated whole-virus porcine parvovirus vaccine protects pigs against disease but does not prevent virus shedding even after homologous virus challenge.

Inactivated whole-virus vaccines against porcine parvovirus (PPV) can prevent disease but not infection and virus shedding after heterologous virus challenge. Here, we showed that the same is true for a homologous challenge. Pregnant sows were vaccinated with an experimental inactivated vaccine based on PPV strain 27a. They were challenged on day 40 of gestation with the virulent porcine parvovirus PPV-27a from which the vaccine was prepared (homologous challenge). On day 90 of gestation, the fetuses from vaccinated sows were protected against disease, while the fetuses of the non-vaccinated sows (control group) exhibited signs of parvovirus disease. All gilts, whether vaccinated or not vaccinated, showed a boost of PPV-specific antibodies indicative of virus infection and replication. Low DNA copy numbers, but not infectious virus, could be demonstrated in nasal or rectal swabs of immunized sows, but high copy numbers of challenge virus DNA as well as infectious virus could both be demonstrated in non-vaccinated sows.

Implementation of a vaccine against Shigatoxin 2e in a piglet producing farm with problems of Oedema disease: case study.

Oedema disease is one of the major diseases in pigs during the nursery period. It is caused by Shigatoxin 2e producing strains of Escherichia coli. In order to combat the disease, the metaphylactic use of colistin sulphate and zinc oxide is widely spread. Additionally, special feeding regimens such as the reduction of the amount of crude protein and the increase of the amount of crude fibre are applied. The goal of this study was to test the efficacy of a vaccine against Oedema disease caused by Shigatoxin 2e in a field trial on a farm with a history of Oedema disease in nursery pigs. The study was carried out on a Dutch farm with 600 sows and a one-week farrowing rhythm and lasted for the time of one year. During this time all piglets were vaccinated with 1 ml ECOPORC SHIGA at the average age of 4 days. The parameters Overall mortality, use of antimicrobials in general, calculated as defined daily dose per animal, use of colistin sulphate and the weight gain were evaluated for all nursery pigs and compared to historical data of animals from the same period of time directly prior to the study serving as a historical control group. The previous mortality in the nursery of 7.7% was significantly reduced to 1.3% after vaccination. The metaphylactic use of colistin sulphate during the nursery period was stopped during the study because no deaths due to Oedema disease had occurred anymore after beginning of vaccination. The defined daily dose per animal per month was significantly reduced from a mean of 1.050 in the year 2012 to a mean of 0.215 in the year 2013. The defined daily dose per animal per year was therefore relevantly reduced from 12.6 in 2012 to 2.6 in 2013. These results show that on this farm Oedema disease can not only be controlled successfully by vaccination but also that vaccination can significantly reduce the use of antimicrobials in the nursery period.

Reassortants of the pandemic (H1N1) 2009 virus and establishment of a novel porcine H1N2 influenza virus, lineage in Germany.

The incursion of pandemic (H1N1) 2009 virus (pdmH1N1) into the German pig population was investigated in a serosurvey and by virological means between June 2009 and December 2012. Analysis of 23,116 pig sera from a total of 2,666 herds revealed 224 herds that reacted with pdmH1N1 but not with the prevalent avian-like H1N1 swine influenza virus. Sixty-six pdmH1N1 strains and their reassortant derivatives (pdmH1huN2, huH3pdmN1) have been collected since November 2009. Sequencing of three pdmH1N1, 20 pdmH1huN2 and one huH3pdmN1 strains with conventional and next generation sequencing techniques and subsequent phylogenetic analyses with available sequence data revealed the emergence of five distinct reassortant genotypes in Europe. The most frequent genotype emerged at least three times independently, one of which (Papenburg lineage) established a stable infection chain and became more prevalent in pigs than pdmH1N1 in Germany.

Duration of immunity induced in chickens by an attenuated live Salmonella enteritidis vaccine and an inactivated Salmonella enteritidis/typhimurium vaccine.

The aim of this study was to examine the duration of immunity of different vaccination schemes using the S. enteritidis live vaccine Gallivac Se and the S. enteritidis-S. typhimurium inactivated vaccine Gallimune Se+St. Three groups of Lohman Brown chickens were used. Group one was vaccinated three times orally with Gallivac Se at weeks one, seven and 13 of age. Group two was vaccinated twice orally with Gallivac Se in weeks one and seven and once i.m. with Gallimune Se+St in week 14 of age. A third group was not vaccinated and served as the control group. Eight randomly selected chickens from each of the three groups were challenged with a nalidixic acid resistant S. enteritidis PT4 strain in weeks 24, 51 and 71 of age and the same number of animals were challenged with a S. typhimurium DT 104 strain in weeks 26, 54 and 73 (75) of age.The chickens were euthanised seven days post challenge and the number of challenge strain organisms (log10 cfu) in the liver and on caecal mucosa was determined.The quantitative investigation of the challenge strain in the liver and caecal mucosa revealed a statistically significant (p < 0.05) lower challenge strain burden in the vaccinated groups compared with the non-vaccinated control group up to week 71 (73) of age. The protective effects were demonstrated for both challenge strains.

[Analysis of the situation of swine influenza in the districts Upper Bavaria, Swabia, Freiburg and Tübingen based on antibody profiles of piglets from Bavarian breeding farms]. / Analyse der Situation der Schweine- influenza in den Bezirken Oberbayern, Schwaben, Freiburg und Tübingen anhand von Antikörperprofilen bayerischer Ferkelaufzuchtbetriebe.

A total of 1026 serum samples from 388 pigs from three Bavarian rearing farms in the region of Swabia were investigated in the course of investigations into the development of antibodies against Influenza A virus subtypes H1N1, H1N2 and H3N2 by haemagglutination inhibition test during the period from November 2002 to February 2004. There were no signs of respiratory disease during this period. The antibody titres decreased steadily in this period which corresponds to the kinetics of maternally-derived antibodies. Therefore the antibodies reflect the situation of influenza in the farms of origin from which the piglets were purchased. These farms were located in Bavaria and Baden-Wuerttemberg. There was a high activity of H1N1 influenza A viruses in this region whereas the antibody profiles against H1N2 and H3N2 varied between the different farms, which can be attributed to past vaccinations and infections. Thus there was a uniform immunological situation within the regions against H1N1 whereas that against H1N2 and H3N2 differed. The analysis of the antibody profiles allows conclusions to be drawn about the epidemiological situation and means of immunoprophylaxis.

[Antibody response after immunization with a Salmonella Typhimurium live vaccine in dependence on the way of application]. / Antikörperantwort nach Impfung von Mastschweinen mit einem Salmonella-Typhimurium-Lebendimpfstoff in Abhängigkeit von der Applikationsform.

In Germany now, the recognition of Salmonella infections in pig herds is based on three different commercial tests detecting antibodies against Salmonella-derived lipopolysaccharide (LPS). However, a serious disadvantage of these tests, used so far, is the restricted detection of antibodies belonging predominantly to the immunoglobulin class g (IgG). Therefore, a new test was developed to detect three Ig classes (IgM, IgG and IgA). Different constellations between the three Ig classes allow the evaluation of the current infection status of each pig. Under field conditions, this was proved in three different vaccination trials using a commercial Salmonella Typhimurium live vaccine.

[Study of the virulence of Actinobacillus pleuropneumoniae in finishing pigs as a basis for vaccination development]. / Studie zur Virulenz von Actinobacillus pleuropneumoniae bei schweren Mastschweinen als Grundlage für die Entwicklung von Impfstoffen.

For vaccine licensing data about efficiency and duration of protection are essential. Within the scope of the developement of a new subunit vaccine against Actinobacillus pleuropneumoniae (A.pp.) the protective efficiency over the whole length of the fattening period must be proven. This required infection experiments in finishing pigs. Eight pigs in the age of six months were infected experimentally into the trachea with an A.pp. serotyp 2 strain. To our knowledge data about the susceptibility of pigs of this age do not exist, so that the infectious dose for pigs of this age and this route of infection had to be determined. Two pigs each were infected with different doses of 10(10), 6 x 10(5), 8 x 10(3) and 2 x 10(3) CFU (colony forming units). The aim of the study was to produce a typical pleuropneumonia with fever and severe respiratory symptoms as well as characteristic pathomorphological lung alterations without loss of animals during the acute stage of infection. The pathogen should be cultivated from lung tissue. The recommended dose for testing the efficiency of vaccines turned out to be approximately 10(3) CFU A.pp. serotyp 2.

Immunity induced with a Salmonella enterica serovar Enteritidis live vaccine is regulated by Th1-cell-dependent cellular and humoral effector mechanisms in susceptible BALB/c mice.

The objective of this study was to characterize the immune response induced by a live attenuated Salmonella Enteritidis (SE; ade(-)/his(-)) vaccine using an intraperitoneal immunization/challenge model in susceptible wild-type and cytokine-deficient BALB/c mice. In wild-type mice, inoculation of the SE live vaccine induced a protective immune response characterized by both cellular (production of interleukin(IL)-12 and interferon(IFN)-gamma, granuloma formation in liver and spleen, DTH response) and humoral effector mechanisms (high antigen-specific IgG2a titers). IL-12- and IL-4-deficient mice were immunized to study the individual roles of Th1 and Th2 cells, respectively. Protective immunity in wild-type mice required inoculation of >5 x 10(3)CFU of the attenuated live SE vaccine strain used. While IL-4-deficient mice developed a protective immune response similar to that found in wild-type mice, it was not possible to induce protective immunity in the highly susceptible IL-12-deficient mice due to severe disease symptoms and death following inoculation of the SE vaccine strain (doses >or=5 x 10(2)CFU were lethal for IL-12-deficient mice). Interestingly, persistence of the vaccine strain was observed in IL-4-deficient mice, indicating a role of IL-4 for clearance which, however, did not interfere with protective immunity. Together, the data indicate that the SE live vaccine activates a cellular and a humoral immune response, which are both regulated by Th1 cells via the secretion of IFN-gamma, whereas Th2 cells did not contribute essentially to the SE live-vaccine-induced immunity.

Real-time PCR protocol for the detection of porcine parvovirus in field samples.

This report describes a real-time polymerase chain reaction assay with SYBR Green for detection of a broad range of porcine parvoviruses (PPV) and accurate virus quantification in porcine tissues. The assay targets the VP2 gene of PPV and the porcine genomic c-myc gene for normalization. The detection limit of the SYBR Green reaction was shown to be equivalent to 6 x 10(0) to 6 x 10(1) PPV copies/reaction and the overall detection limit equivalent to 0.1 TCID(50)/100 microl. The assay was linear over a 10(7) dilution range of template concentrations. Other porcine pathogens involved in reproductive disorders such as porcine circovirus 2 (PCV-2), porcine reproductive and respiratory virus (PRRSV), Aujeszky's disease virus (PRV) and other parvoviruses such as feline parvovirus (FPV), canine parvovirus (CPV), minute virus of canines (MVC) and a human parvovirus (B19) were not detected by this assay.

[The humeral immune response of swine after experimental infection with Salmonella typhimurium]. / Untersuchungen zur humoralen Immunantwort des Schweines nach experimenteller Infektion mit Salmonella Typhimurium.

LPS antibody reaction of S. Typhimurium was detected in a total of 111 two- to ten-week-old pigs, which had been exposed to experimental oral infection with this serovar in 16 separate experiments. The total antibody level was determined according to the meat juice ELISA provided for the Salmonella control programme and the antibody concentrations of the isotopes IgG1, IgG2, IgA and IgM. Although there were significant differences between the individual experiments with respect to the reaction intensity and proportion of the individual immune globulin isotypes, the following general statements on the dynamics of the antibody reaction can be made: Clearly elevated antibody levels could be observed one week after the onset of infection. After one and two weeks, respectively, 22.5 and 52.9% of the infected animals showed antibody levels which were to be evaluated as positive in the sense of the Salmonella control programme (> or = 40%). While the concentration of the IgM-related antibodies decreased again during the second week already, the antibody concentration of IgG1 and IgG2 continued to increase until the end of the experiment after 3 weeks. The clear differences in the reactions between the experiments cannot be explained solely by defined conditions of infection such as strain of infection, infective dose or age of the pigs. Obviously, other non-defined or non-recognized factors may have a decisive influence on the dynamics of the antibody reaction in the animal groups.