Characterization of immunostimulatory components of orf virus (parapoxvirus ovis).

Inactivated orf virus (ORFV, parapoxvirus ovis) induces antiviral activity in animal models of acute and chronic viral infections and exerts strong effects on human immune cells. ORFV activates antigen presenting cells (APC) via CD14 and, probably, Toll-like receptor signalling, and triggers the release of IFN-γ that has been identified as the key mediator of the antiviral activity. After delineating virus proteins as being the most likely active constituent, we aimed to characterize the ORFV proteins responsible for the therapeutic effect.

Longitudinal prevalence study of diarrheagenic Escherichia coli in dairy calves.

A longitudinal study (cohort study) elaborating 1,224 rectal swabs from 221 calves aging between 1 and 12 weeks was conducted on 11 dairy farms (i) to ascertain associations between diarrhea and shedding of diarrheagenic E. coli and (ii) to facilitate the zoonotic potential assessment of E. coli strains shed by young calves.

Immunization with an alphatoxin variant 121A/91-R212H protects mice against Clostridium perfringens alphatoxin.

As shown previously, a recombinant alphatoxin variant (rAT121A/91) constructed from the naturally occurring Clostridium perfringens mutant strain 121A/91, was devoid of enzymatic (PLC), hemolytic and lethal activity (18). In the present study, the recombinant variant was altered by an oligonucleotide-directed reversion of an arginine in position 212 for a histidine residue, corresponding to the sequence of the wild-type alphatoxin. The new variant rAT121A/91R212H proved to be negative in enzymatic, hemolytic and lethal activity as well.

DNA-loaded bacterial ghosts efficiently mediate reporter gene transfer and expression in macrophages.

There is a demand for efficient and safe DNA delivery vehicles mediating gene transfer and expression. We present bacterial ghosts as a novel platform technology for DNA delivery and targeting of macrophages. Bacterial ghosts are cell envelopes of gram-negative bacteria that are devoid of the cytoplasmic content.

Reinfection with Chlamydophila abortus by uterine and indirect cohort routes reduces fertility in cattle preexposed to Chlamydophila.

This study investigated the effects of controlled reinfection on fertility of cattle naturally preexposed to Chlamydophila abortus. All animals had high prechallenge levels of immunoglobulin M (IgM), IgG, IgG1, and IgG2 serum antibodies against ruminant C. abortus in a chemiluminescent enzyme-linked immunosorbent assay.

Induction of an antigen-specific immune response and partial protection of cattle against challenge infection with foot-and-mouth disease virus (FMDV) after lipopeptide vaccination with FMDV-specific B-cell epitopes.

To evaluate the potential of chemically synthesized lipopeptides for vaccination against foot-and-mouth disease (FMD), seven lipopeptides containing the immunostimulating principle of bacterial lipoproteins and linear B-cell epitopes of FMDV strain O(1)Kaufbeuren (O(1)K) were used to immunize cattle (n=7). Animals were vaccinated once and 21 days after immunization animals were infected with the homologous virus. Four animals were protected.

Pasteurella multocida- and Pasteurella haemolytica-ghosts: new vaccine candidates.

Pasteurella multocida is an important animal pathogen. Bacterial ghosts produced by the expression of phage PhiX174 lysis gene E are empty cells devoid of cytoplasmic and genomic material. Lysis of P.

Identification of foot-and-mouth disease virus-specific linear B-cell epitopes to differentiate between infected and vaccinated cattle.

Foot-and-mouth disease (FMD) is a highly contagious viral disease of cloven-hoofed animals. For several years, vaccination of animals, which had proven to be successful for the eradication of the disease, has been forbidden in the United States and the European Community because of the difficulty of differentiating between vaccinated and infected animals. In this study, detailed investigations of the bovine humoral immune response against FMD virus (FMDV) were performed with the aim of identifying viral epitopes recognized specifically by sera derived from FMDV-infected animals.

Inactivated parapoxvirus ovis (Orf virus) has antiviral activity against hepatitis B virus and herpes simplex virus.

It is known that some viruses are able to induce vigorous immune reactions. This study shows that inactivated parapoxvirus ovis (Orf virus), strain D1701 (PPVO), induces an autoregulatory cytokine response that involves the upregulation of IL-12, IL-18, IFN-gamma and other T helper 1-type cytokines and their subsequent downregulation, which is accompanied by induction of IL-4. An increase in IL-10 expression was also found in the livers of PPVO-treated mice.

Quantitative detection of Chlamydia psittaci and C. pecorum by high-sensitivity real-time PCR reveals high prevalence of vaginal infection in cattle.

Bovine vaginal cytobrush specimens were analyzed for the presence of Chlamydia spp. by a high-sensitivity, high-specificity quantitative PCR. The 53% prevalence of low-level Chlamydia psittaci and C.

Protective immunity against pasteurellosis in cattle, induced by Pasteurella haemolytica ghosts.

Pasteurella haemolytica is a cattle pathogen of significant economic impact. An effective vaccine against bovine pneumonic pasteurellosis is therefore of high importance. Apart from economic concerns, pasteurellosis caused by P.

The quantity of nitric oxide released by macrophages regulates Chlamydia-induced disease.

Intracellular bacteria of the genus Chlamydia cause numerous typically chronic diseases, frequently with debilitating sequelae. Genetic determinants of disease susceptibility after infection with Chlamydia bacteria are unknown. C57BL/6 mice develop severe pneumonia and poor immunity against Chlamydia after moderate respiratory infection whereas BALB/c mice are protected from disease and develop vigorous Th1 immunity.

Naturally occurring Clostridium perfringens nontoxic alpha-toxin variant as a potential vaccine candidate against alpha-toxin-associated diseases.

Clostridium perfringens mutant strain 121A/91 shows neither enzymatic (phospholipase C) nor hemolytic activity. Nevertheless, the cpa gene and the corresponding alpha-toxin variant are detectable. Vaccination with this genetically constructed alpha-toxin variant, rAT121/91, induces antibodies capable of significantly reducing activities induced by wild-type toxin.

Expression of a VEGF-like protein from Parapoxvirus ovis in the yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe.

We report on the expression of a VEGF-like protein encoded by Parapoxvirus ovis in the yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe. We show that a lysine residue at amino acid position 2 (K2) is an important determinant for the stability of this protein in S. cerevisiae.

Quantitative detection of Chlamydia spp. by fluorescent PCR in the LightCycler.

Quantitative detection of intracellular bacteria of the genus Chlamydia by the standard cell culture method is cumbersome and operator dependent. As an alternative, we adapted hot-start PCR to the glass capillary quantitative PCR format of the LightCycler. The optimized PCR was consistently more efficient than commercially available pre-assembled PCRs.

Recombinant bovine adenovirus type 3 expressing bovine viral diarrhea virus glycoprotein E2 induces an immune response in cotton rats.

Recombinant bovine adenovirus is being developed as a live vector for animal vaccination and for human gene therapy. In this study, two replication-competent bovine adenovirus 3 (BAV-3) recombinants (BAV331 and BAV338) expressing bovine viral diarrhea virus (BVDV) glycoprotein E2 in the early region 3 (E3) of BAV-3 were constructed. Recombinant BAV331 contains chemically synthesized E2 gene (nucleotides modified to remove internal cryptic splice sites) under the control of BAV-3 E3/major late promoter (MLP), while recombinant BAV338 contains original E2 gene under the control of human cytomegalovirus immediate early promoter.

Evidence for a parapox ovis virus-associated superantigen.

As shown in a number of species, susceptibility to infectious diseases can be efficiently reduced following application of inactivated parapox ovis viruses (iPPOV). However, the basic mechanism for this stimulating capacity of iPPOV remains unclear. When analyzed, the interaction of iPPOV with porcine peripheral blood mononuclear cells was seen to involve T helper cells as the main target cell population responding to iPPOV.

Poxvirus-induced immunostimulating effects on porcine leukocytes.

The prophylactic application of inactivated parapox ovis viruses (Baypamun; Bayer AG, Leverkusen, Germany) has been shown to reduce efficiently the outbreak of stress-mediated diseases in different species. However, little is known about the basic mechanism behind this observed stimulatory property. We therefore tested eight inactivated poxvirus strains belonging to three different genera (Orthopoxvirus, Avipoxvirus, and Parapoxvirus) for their capacity to activate cells of the porcine innate and specific immune systems in vitro.

Shiga toxin 1 from Escherichia coli blocks activation and proliferation of bovine lymphocyte subpopulations in vitro.

Shiga toxin-producing Escherichia coli (STEC) is widespread in the cattle population, but the clinical significance of Shiga toxins (Stx's) for the bovine species remains obscure. Since Stx's exert immunomodulating effects in other species, we examined the effect of purified Stx1 on a bovine B lymphoma cell line (BL-3) and peripheral blood mononuclear cells (PBMC) isolated from adult bovine blood by viability assays and flow cytometry analysis. Stx1 markedly induced apoptosis in stimulated BL-3 cells.

Controlled multiplex PCR of enterotoxigenic Clostridium perfringens strains in food samples.

A controlled multiplex polymerase chain reaction (PCR) for the detection of Clostridium(C.) perfringens enterotoxin gene (cpe) was established and compared with an in vitro antigenic detection method. Thecpe PCR and the classical method of electric immunodiffusion gave identical results.

The use of Baypamun N in crowding associated infectious respiratory disease: efficacy of Baypamun N (freeze dried product) in 4-10 month old horses.

The efficacy of an immunomodulator, Baypamun N, was tested in 4-10-month-old horses which were exposed to stress by weaning, transport and commingling with yearlings from different breeders (crowding). Verum (n = 26) and placebo animals (n = 27) received three intramuscular injections of the investigational preparations (days 0, 2, 9) starting at the day of commingling in one stable. The incidence of acute respiratory disease was high during the first 4 weeks after commingling.

Neutralization of hemolytic and mouse lethal activities of C. perfringens alpha-toxin need simultaneous blockade of two epitopes by monoclonal antibodies.

Three murine monoclonal antibodies (MAbs 3B4, 1E8, 1F9) were produced by fusion of X63-Ag8.653 myeloma cells and splenocytes of mice immunized with glutaraldehyde-inactivated alpha-toxin of Clostridium perfringens. All MAbs belonged to the immunoglobulin G (IgG) class and possessed a kappa light chain.

Shiga toxin-producing Escherichia coli strains from bovines: association of adhesion with carriage of eae and other genes.

Out of 174 bovine Shiga toxin-producing Escherichia coli (STEC) strains isolated from diarrheic calves in Germany and Belgium, 122 strains (70.1%) were selected because of their reactivity with the eae (E. coli attaching and effacing gene) probe ECW1-ECW2.

The enterohemolysin phenotype of bovine Shiga-like toxin-producing Escherichia coli (SLTEC) is encoded by the EHEC-hemolysin gene.

Naturally occurring enterohemolysin negative variants were observed during studies on bovine Shiga-like toxin-producing E. coli (SLTEC). Examination of three strains (413/89-1 and 332, 026:H-, and 570/89, O111:H-) and their isogenic variants (413/89-6, 332-I and 570/89-I, respectively) showed, that in each strain loss of the enterohemolytic phenotype correlated with the loss of a large plasmid ranging from 94 to 104 kb in size.

The region between the M and S genes of porcine haemagglutinating encephalomyelitis virus is highly similar to human coronavirus OC43.

The nucleotide sequences of the regions between the membrane and spike protein genes of three strains of porcine haemagglutinating encephalomyelitis virus (HEV) were determined. A total of 739 (HEV strain 67N) and 751 (strains NT9 and VW572) nucleotides were sequenced. Two ORFs, potentially encoding proteins of 12.