The role of Mac-1 as a receptor for Bordetella bronchiseptica infection of alveolar macrophages (AMphi) was examined using 6 strains (2 ATCC and 4 pathogenic field isolates) to assess B. bronchiseptica binding, uptake and replication in primary porcine AMphi. All B. bronchiseptica strains were rapidly killed by porcine serum in a dose- and time-dependent manner. However, heat-inactivated porcine serum (HIS) did not demonstrate any bacterial-killing activity, suggesting that complement may have a direct killing activity. All field isolates were more resistant to direct complement-mediated B. bronchiseptica killing. The uptake of B. bronchiseptica into AMphi was inhibited approximately 50% by antiMac-1 monoclonal antibodies in the medium. However, B. bronchiseptica phagocytosed in the presence of serum or HIS was not altered by anti-Mac-1 antibodies although more bacteria were internalized by addition of serum or HIS. These data suggest that Mac-1 is a target for direct uptake of B. bronchiseptica via opsoninindependent binding. The phagocytosed B. bronchiseptica, either via direct or serum-mediated binding, were efficiently killed by AMphi within 10 hr postinfection. This demonstrates that Mac-1-mediated B. bronchiseptica uptake is a bacterial killing pathway not leading to productive infections in AMphi.
Animals ; Antibodies, Bacterial/blood/immunology ; Bordetella bronchiseptica/*immunology ; Macrophage-1 Antigen/*immunology ; Macrophages, Alveolar/*immunology ; Phagocytosis ; Protein Binding ; Swine/*immunology/*microbiology

Actinobacillus pleuropneumoniae (A. pleuropneumoniae), the causative agent of porcine contagious pleuropneumonia (PCP), is a significant pathogen of the world pig industry, vaccination is potentially an effective tool for the prevention of PCP. The purpose of present study was to enhance the immunogenicity of A. pleuropneumoniae live vaccine strain HB04C- (serovar 7), which was unable to express ApxIA, and to develop effective multivalent vaccines for the respiratory pathogens based on the attenuated A. pleuropneumoniae. We introduced a shuttle vector containing intact apxIA gene into HB04C-, generating HB04C2, an A. pleuropneumoniae serovar 7 live attenuated vaccine strain co-expressing ApxIA. Then we investigated the biological characteristics of HB04C2. We found that the shuttle vector expressing ApxIA was stable in HB04C2, and the growth ability of HB04C2 was not affected by the shuttle vector. We observed that HB04C2 elicited detectable antibodies against ApxIA and ApxIIA when it was administrated intratracheally as a live vaccine in pigs, and all immunized pigs were protected from heterologous virulent A. pleuropneumoniae (serovar 1) challenge. In conclusion, we demonstrated that A. pleuropneumoniae live vaccine could be used as a vector for expression of heterologous antigens.
Actinobacillus Infections ; prevention & control ; veterinary ; Actinobacillus pleuropneumoniae ; classification ; immunology ; Animals ; Bacterial Proteins ; biosynthesis ; genetics ; Bacterial Vaccines ; biosynthesis ; immunology ; Hemolysin Proteins ; biosynthesis ; genetics ; Pleuropneumonia ; microbiology ; prevention & control ; Swine ; Swine Diseases ; microbiology ; prevention & control ; Vaccines, Attenuated ; biosynthesis ; immunology

In the present study, Staphylococcus (S.) hyicus strains isolated in Russia (n = 23) and Germany (n = 17) were investigated for the prevalence of the previously described genes sheta and shetb. Sheta was detected in 16 S. hyicus strains. Sheta-positive strains were mainly found among strains isolated from exudative epidermitis, and frequently together with the exfoliative toxin-encoding genes exhD and exhC. Partial sequencing of sheta in a single S. hyicus strain revealed an almost complete match with the sheta sequence obtained from GenBank. None of the S. hyicus strains displayed a positive reaction with the shetb-specific oligonucleotide primer used in the present study. According to the present results, the exotoxin encoding gene sheta seems to be distributed among S. hyicus strains in Russia and Germany. The toxigenic potential of this exotoxin, which does not have the classical structure of a staphylococcal exfoliative toxin, remains to be elucidated.
Animals ; Cattle ; Cattle Diseases/epidemiology/microbiology ; DNA Primers ; Dog Diseases/epidemiology/microbiology ; Dogs ; Epidermitis, Exudative, of Swine/epidemiology ; Exfoliatins/*genetics/immunology ; Germany ; Pneumonia/epidemiology/veterinary ; Russia ; Staphylococcal Infections/immunology/veterinary ; Staphylococcus aureus/genetics/*pathogenicity ; Swine ; Swine Diseases/epidemiology ; Virulence/*genetics ; Virulence Factors/genetics/immunology

In order to obtain an attenuated vaccine candidate for enteropathogenic Escherichia coli (EPEC) O45, a ler deletion mutant of pig enteropathogenic E. coli (PEPEC) O45 was constructed by using the suicide vector pCVD442, termed as PEPEC O45(deltaler). The culture supernatant of PEPEC O45(deltaler) deletion mutant was inoculated in vero cell culture. PEPEC O45(deltaler) deletion mutant lost the toxigenicity to vero cell. Test group and control group of mice were orogstrically inoculated with the PEPEC O45(deltaler) deletion mutant and the virulent strain O45 respectively. Mice were observed daily for clinical signs and weight changes. Test group of mice inoculated with PEPEC O45(deltaler) gained weight normally and experienced no clinical signs. In contrast, control group of mice inoculated with virulent strain O45 exhibited weight loss and all died in four days. In another experiment, pregnant mice and pig were orally vaccinated by PEPEC O45(deltaler) twice at interval of 14 days respectively. Subsequently, the suckling mice and pig were orally challenged with O45 at 7 days of age respectively. The results showed that 80% of the sucking mice born by vaccinated mice and 75% of the sucking pig born by vaccinated pig were survival; 15% of the sucking mice born by non-vaccinated mice and 10% of the sucking pig born by non-vaccinated pig were survival. This study demonstrated that PEPEC O45(deltaler) deletion mutant lost the toxigenicity to vero cell and to be safety to mice and pig. Oral immunization can induce specific immune responses in mice and pig, and this mutant strain could be used as an attenuated vaccine candidate against PEPEC O45.
Animals ; Enteropathogenic Escherichia coli ; genetics ; immunology ; Escherichia coli Infections ; microbiology ; prevention & control ; Escherichia coli Proteins ; genetics ; Escherichia coli Vaccines ; biosynthesis ; genetics ; immunology ; Gene Deletion ; Mice ; Mutagenesis, Site-Directed ; Swine ; microbiology ; Swine Diseases ; microbiology ; prevention & control ; Trans-Activators ; genetics ; Vaccines, Attenuated ; biosynthesis ; genetics ; immunology

Five monoclonal antibodies (MAbs) and chicken immunoglobulin (IgY) were developed by immunizing with flagella purified from Listeria monocytogenes 4b and the five MAbs have been confirmed to be specific against three different epitopes of flagellin. The antibodies showed specific reaction to Listeria genus and no cross-reactivity with other bacteria tested in this experiment including E.coli O157:H7 and Salmonella enteritidis. Sandwich enzyme-linked immunosorbent assays (ELISA) using the MAbs and IgY were developed to detect Listeria species and the sensitivity and specificity of the developed ELISA have been analyzed. The detection limit of ELISA using MAb 2B1 and HRP labeled IgY was 1 x105cells/0.1 ml at 22degrees C and 1x106 cells/0.1 ml at 30degrees C. ELISA using the pair of MAbs (MAbs 2B1 and HRP labeled MAbs 7A3) detected up to 104cells/0.1 ml at 22degrees C and 30degrees C. Detection limit of sandwich ELISA using IgY was 10 times lower than MAb pair. Using the developed ELISA, we could detect several Listeria contaminated in food samples after 48 h-culturing. In conclusion, both MAbs and IgY have been proved to be highly specific to detect Listeria flagella and the developed sandwich ELISA using these antibodies would be useful tool for screening Listeria spp. in food.
Animals ; Antibodies, Bacterial/*chemistry ; Antibodies, Monoclonal ; Antibody Specificity ; Antigens, Bacterial/analysis ; Enzyme-Linked Immunosorbent Assay/*methods ; Flagella/*genetics ; Food Microbiology ; Immunoglobulins/analysis ; Listeria/*classification/immunology/*isolation&purification ; Meat/microbiology ; Milk/microbiology ; Sensitivity and Specificity ; Swine

Swine respiratory diseases induce severe economic losses in the swine industry worldwide. Several methods have been developed and applied to control these diseases. However, there are still problems of disease control in the swine industry. Recently, egg yolk antibodies have been found to offer several advantages for disease control in animals and humans. In a previous study (24), antibodies to several causative pathogens of swine respiratory diseases were developed. However, several problems remained, especially in terms of reduced laying rates. Therefore, experimental vaccines were reformulated with various bacterial antigens of the swine respiratory diseases. After immunizing hens with the antigens, antibody profiles and other effects including laying rates were investigated and compared to those of the previous study. Profiles of antibody titers were very similar with those of the previous study. However, side effects, such as depression, weakness, reduction of laying rates and mortality, were dramatically lowered and laying rates were increased in hens injected with certain experimental vaccines. In particular, laying rates of hens injected with vaccines against atrophic rhinitis were increased up to 84% by injecting a vaccine composed of only the DNTs of B. bronchiseptica and P. multocida D:4. Efficacies of the vaccines against swine pneumonic pasteurellosis and pleuropneumonia were very similar with those of the previous study. These results suggest that new vaccines could be effective in the production of egg yolk antibodies against the causative agents of swine respiratory diseases.
Actinobacillus pleuropneumoniae/classification/genetics/*immunology ; Animals ; Antibodies, Bacterial ; Antibody Formation ; Bacterial Outer Membrane Proteins/genetics/isolation & purification ; Bordetella bronchiseptica/classification/genetics/*immunology ; Egg Yolk/microbiology ; Female ; Immunoglobulins/*genetics ; Oviposition ; Pasteurella multocida/classification/genetics/*immunology ; Serotyping ; Swine

Verocytotoxic Escherichia (E.) coli strains are responsible for swine oedema disease, which is an enterotoxaemia that causes economic losses in the pig industry. The production of a vaccine for oral administration in transgenic seeds could be an efficient system to stimulate local immunity. This study was conducted to transform tobacco plants for the seed-specific expression of antigenic proteins from a porcine verocytotoxic E. coli strain. Parameters related to an immunological response and possible adverse effects on the oral administration of obtained tobacco seeds were evaluated in a mouse model. Tobacco was transformed via Agrobacteium tumefaciens with chimeric constructs containing structural parts of the major subunit FedA of the F18 adhesive fimbriae and VT2e B-subunit genes under control of a seed specific GLOB promoter. We showed that the foreign Vt2e-B and F18 genes were stably accumulated in storage tissue by the immunostaining method. In addition, Balb-C mice receiving transgenic tobacco seeds via the oral route showed a significant increase in IgA-positive plasma cell presence in tunica propria when compared to the control group with no observed adverse effects. Our findings encourage future studies focusing on swine for evaluation of the protective effects of transformed tobacco seeds against E. coli infection.
Administration, Oral ; Agrobacterium tumefaciens ; Animals ; Antigens, Bacterial/genetics/metabolism ; Bacterial Vaccines/administration & dosage/adverse effects/*pharmacology ; Edema Disease of Swine/*immunology/microbiology ; Escherichia coli Infections/immunology/microbiology/*veterinary ; Escherichia coli Proteins/*genetics/metabolism ; Female ; Fimbriae Proteins/genetics/metabolism ; Genetic Engineering ; Intestines/immunology/microbiology/pathology ; Mice ; Mice, Inbred BALB C ; Models, Animal ; Plants, Genetically Modified/*genetics/metabolism ; Seeds/genetics/metabolism ; Shiga Toxin 2/genetics/metabolism ; Shiga-Toxigenic Escherichia coli/genetics/immunology/*pathogenicity ; Swine ; Tobacco/*genetics/metabolism ; Virulence Factors/genetics/metabolism

Porcine proliferative enteropathy(PPE) is an enteric disease been caused by Lawsonia intracellularis. It has become one of the critical problems in the pig industry. To investigate the prevalence of PPE in Korea, serum samples of 828 pigs from 65 herds were tested using indirect immunofluorescence antibody technique(IFA). The infection rate in individual pigs varied from 44 to 69%, whereas 100% in pig farms. The infection frequency was 57, 44.9, and 59.4% according to age respectively. Administration of tylosin in feed at a concentration of 110 ppm for 14 days reduced the infection rate of the farms. These data indicated that the high prevalence of PPE may be controlled by tylosin.
Administration, Oral ; Animal Feed ; Animals ; Anti-Bacterial Agents/*therapeutic use ; Antibodies, Bacterial/blood ; Enteritis/epidemiology/prevention&control/*veterinary ; Fluorescent Antibody Technique, Indirect/veterinary ; Gram-Negative Bacterial Infections/prevention&control/*veterinary ; Korea/epidemiology ; *Lawsonia Bacteria/drug effects/growth&development/immunology ; Seroepidemiologic Studies ; Swine ; Swine Diseases/*epidemiology/microbiology/prevention&control ; Tylosin/*therapeutic use

OBJECTIVETo develop a safe and novel immunoadjuvant to enhance the immunity and resistance of animals against E. coli infection.

METHODSAn 88-base immunostimulatory oligodeoxynuleotide containing eleven CpG motifs (CpG ODN) was synthesized and amplified by PCR. The chitosan nanoparticle (CNP) was prepared by ion linking method to entrap the CpG ODN that significantly promotes the proliferation of lymphocytes of pig in vitro. Then the CpG-CNP was inoculated into 21-day old Kunming mice, which were orally challenged with virulent K88/K99 E. Coli 35 days after inoculation. Blood was collected from the tail vein of mice on days 0, 7, 14, 21, 28, 35, 42, and 49 after inoculation to detect the changes and content of immunoglobulins, cytokines and immune cells by ELISA, such as IgG, IgA, IgM, IL-2, IL-4, and IL-6.

RESULTSThe CpG provoked remarkable proliferation of lymphocytes of pig in vitro in comparison with that of control group (P < 0.05). The inoculation with CpG-CNP significantly raised the content of IgG, IgM, and IgA in the sera of immunized mice (P < 0.05). The levels of IL-2, IL-4, and IL-6 in the mice significantly increased in comparison with those in controls (P < 0.05), so was the number of white blood cells and lymphocytes in immunized mice. The humoral and cellular immunities were significantly enhanced in immunized mice, which resisted the infection of E. coli and survived, while the control mice manifested evident symptoms and lesions of infection.

CONCLUSIONSCpG-CNP can significantly promote cellular and humoral immunity and resistance of mice against E. coil infection, and can be utilized as an effective adjuvant to improve the immunoprotection and resistance of porcine against infectious disease.

Adjuvants, Immunologic ; administration & dosage ; Animals ; Antibodies, Bacterial ; blood ; Biocompatible Materials ; administration & dosage ; Chitosan ; administration & dosage ; CpG Islands ; Escherichia coli ; pathogenicity ; Escherichia coli Infections ; immunology ; microbiology ; prevention & control ; Female ; Immunity, Cellular ; Interleukins ; biosynthesis ; Lymphocyte Activation ; Mice ; Nanoparticles ; Oligodeoxyribonucleotides ; administration & dosage ; Swine ; Vaccination