OBJECTIVETo investigate the seroprevalence of HEV infection in human population, swine and chicken in Beijing region.

METHODSEIA was used for detecting anti-HEV IgG of the serum samples. All samples were collected in 2006-2007 in Beijing areas.

RESULTSThe anti-HEV IgG was detected positive in 21.52% of human (260/1208), 46.88 % (15/32) of swine, but was negative in chickens (0/24). The positive rate of human at different age group, was 5.60% (14/250) of 11-20 year, 20% (42/210) of 21-30 year, 24.03% (62/258) of 31-40 year, 26.44% (78/295) of 41-50 year, 32.82% (64/195) of 51-60 year. The male (29.51%) was higher than the female (21.70%).

CONCLUSIONThe HEV infection was correlation with age and sex significantly. The infection rate was increased with age, the positive rate in swine was more double than the human population.

Adolescent ; Adult ; Animals ; Chickens ; Child ; China ; Female ; Hepatitis Antibodies ; blood ; Hepatitis E ; immunology ; veterinary ; virology ; Hepatitis E virus ; immunology ; Humans ; Immunoglobulin G ; blood ; Male ; Middle Aged ; Poultry Diseases ; immunology ; virology ; Swine ; Swine Diseases ; immunology ; virology ; Young Adult

OBJECTIVETo investigate hepatitis E virus (HEV) infection among pigs in Henan province.

METHODSA total of 623 swine sera, collected from 5 districts, were divided into two groups, under 3-month of age and over 3-month of age. They were tested for HEV antigen and antibody by using ELISAs, respectively. The sera positive for HEV antigen were tested for HEV RNA with RT-PCR. The positive products of RT-PCR were cloned and sequenced.

RESULTSThe positive rates of anti-HEV antibody of the groups under 3-month and over 3-month of age were 90.27% and 92.55%, respectively, without statistical difference, while those of HEV antigen were 15.93% and 5.69%, respectively, with significant difference. The positive rates of anti-HEV antibody and HEV antigen were significantly different among different districts. HEV RNA was detectable in 5 of 47 HEV antigen positive samples. The sequence analysis showed that in 4 of 5 specimens the sequence belonged to genotype 4 while in the remaining one the sequence was genotype 1.

CONCLUSIONThe prevalence rate of HEV infection in pigs was high in Henan province and the rate differed in different districts.

Animals ; Antibodies, Viral ; analysis ; immunology ; Antigens, Viral ; analysis ; immunology ; China ; Genotype ; Hepatitis E ; epidemiology ; immunology ; veterinary ; virology ; Hepatitis E virus ; genetics ; immunology ; isolation & purification ; Phylogeny ; RNA, Viral ; analysis ; genetics ; Sequence Analysis, DNA ; Swine ; virology ; Swine Diseases ; epidemiology ; immunology ; virology

The Japanese encephalitis virus (JEV) is one of causative agents of reproductive failure in pregnant sows. An indirect enzyme-linked immunosorbent assay (I-ELISA) was examined for its potential use in the rapid monitoring of the JEV, and the results were compared with those from the hemagglutination inhibition (HI) and serum neutralization (SN) tests. The comparative analysis showed that the results of I-ELISA showed a significant correlation with the conventional HI (r = 0.867) and SN tests (r = 0.804), respectively. When the I-ELISA results were compared with the traditional diagnostic assays, the sensitivity of the I-ELISA was 94.3% with the HI test and 93.7% with the SN test, respectively. The specificity was found to be 81.4% and 80.0% with the HI and SN tests, respectively. To determine the applicability of I-ELISA in the field, the serum samples from 720 pigs were collected from 4 regions in Korea between July and August 2004. The results indicated that 21.7% of screened pigs were seropositive for the JEV. The seropositive rates of JEV in the 4 provinces were 12.6% in Gyeonggi, 45.0% in Gyeongnam, 16.7% in Jeonbuk, and 12.2% in Jeju. The I-ELISA methodology developed in this study was shown to have considerable sensitivity and specificity through a comparison with HI and the SN tests. Therefore, it might be one of convenient methods for screening a large number of samples in various fields.
Animals ; Antibodies, Viral/blood ; Antigens, Viral/immunology ; Encephalitis Virus, Japanese/immunology/*isolation&purification ; Encephalitis, Japanese/blood/immunology/*veterinary/virology ; Enzyme-Linked Immunosorbent Assay/methods/*veterinary ; Female ; Hemagglutination Inhibition Tests/veterinary ; Korea ; Neutralization Tests/veterinary ; Swine ; Swine Diseases/blood/immunology/*virology

Porcine circovirus type 2 (PCV2) is the primary causative agent for post-weaning, multisystemic, wasting syndrome. Consequently, serologic detection of and vaccination against PCV2 are important for the swine industry. Among several serological tests, the enzyme-linked immunosorbent assay (ELISA) is commonly used to measure anti-PCV2 antibody levels. In the present study, we used two commercial ELISA systems to comparatively evaluate anti-PCV2 antibodies in field pigs treated with three different PCV2 vaccines. Among a total of 517 serum samples, the results of the two ELISAs were fully concordant for 365 positive and 42 negative samples, indicating 78.7% agreement. In addition, the Pearson coefficient (0.636) indicated a moderate correlation between data from the two ELISAs. Results from the farms with pigs vaccinated with the three different PCV2 vaccines demonstrated that most of the vaccinated animals underwent seroconversion. However, the increase and duration of antibody titers varied depending on the vaccine, the presence of maternal antibodies, and the vaccination program. PCV2 serologic status and anti-PCV2 antibody levels of herds from this study could be utilized to determine the best timing for vaccination and assessing vaccination compliance.
Aging ; Animals ; Antibodies, Viral/*blood ; Circovirus/*classification/immunology ; Enzyme-Linked Immunosorbent Assay/methods/*veterinary ; Female ; Porcine Postweaning Multisystemic Wasting Syndrome/blood/immunology/*prevention & control ; Republic of Korea/epidemiology ; Swine ; Swine Diseases/*prevention & control/virology ; Viral Vaccines/*immunology

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

To construct secretory expression vector of PPV NS1 gene, the fragment of PPV NS1 gene coding for major antigen region of the NS1 protein was amplified by PCR and inserted into multiple clone site of eukaryotic expression vector pPICZalpha-A. The recombinant pPICZalpha-A-NS1 plasmid was transferred into P. pastoris strain GS115 mediated by electro transform. Recombinant P. pastoris strain GS115 was induced to express the fusion protein by methanol. The expressed and purified protein was analyzed by SDS-PAGE and Western Blot. The recombinant protein was highly-expressed and showed a good immunoreactivity. The indirect ELISA method was developed for detecting antibodies against PPV by checkerboard titration assay. The result showed that the optimal concentration of coated antigen was 3.2 microg/mL and the best dilution of serum was 1 : 80. The positive cut-off value of the ELISA assay was OD450 > 0.4 and OD450 positive serum/OD450 negative serum > 2.0. Compared with HI and commercial ELISA kits, the assay revealed 94.2% and 92.1% agreement respectively. The assay demonstrates good specificity and sensitivity, and can be applied in the detection of porcine parvovirus.
Animals ; Antibodies, Viral ; immunology ; Antigens, Viral ; genetics ; immunology ; Enzyme-Linked Immunosorbent Assay ; methods ; Escherichia coli ; genetics ; metabolism ; Gene Expression ; Parvoviridae Infections ; diagnosis ; immunology ; veterinary ; virology ; Parvovirus, Porcine ; genetics ; immunology ; isolation & purification ; Recombinant Proteins ; genetics ; immunology ; Swine ; Swine Diseases ; diagnosis ; immunology ; virology ; Viral Nonstructural Proteins ; genetics ; immunology

BACKGROUNDTo investigate the prevalence of anti-HEV among swine, sheep and chickens.

METHODSTotally 498 sera of swine, sheep and chickens collected from Xingjiang, Guangxi, Guangdong, Beijing and Hebei were detected for the anti-HEV by an enzyme linked immunoassay.

RESULTSThe anti-HEV positive rate of swine was 67.53%(104/154), in pigs between 4-5 months of age the rate was 100.00%(9/9) from Xingjiang. The rate in pigs under 3 months of age from Guangxi was 36.00%(9/25) and in pigs older than six months of age was 71.67% (86/120), respectively. The 108 sera of sheep collected from Xingjiang were all negative. The positive rate of chickens was only 1.27% (3/236). The anti-HEV prevalence rates of chickens from Luoding, Shenzhen, Liuzhou, Beijing and Hebei were 4.00%, 1.49%, 1.49%, 0, 0 respectively.

CONCLUSIONHEV infection does exist among swine and chickens. The anti-HEV prevalence of swine was the highest among domestic animals. The role of swine and chickens in transmission of HEV needs to be further studied.

Animals ; Antibodies, Viral ; Chickens ; China ; epidemiology ; Hepatitis Antibodies ; blood ; Hepatitis E ; epidemiology ; veterinary ; Hepatitis E virus ; immunology ; Poultry Diseases ; epidemiology ; virology ; Prevalence ; Sheep ; Sheep Diseases ; epidemiology ; virology ; Swine ; Swine Diseases ; epidemiology ; virology

Virus-like particles (VLPs) composed of the truncated capsid protein of swine hepatitis E virus (HEV) were developed and immune responses of mice immunized with the VLPs were evaluated. IgG titers specific for the capsid protein of swine HEV were significantly higher for all groups of mice immunized with the VLPs than those of the negative control mice. Splenocytes from mice immunized with the VLPs also produced significantly greater quantities of interferon (IFN)-gamma than interleukin (IL)-4 and IL-10. These newly developed swine HEV VLPs have the capacity to induce antigen-specific antibody and IFN-gamma production in immunized mice.
Animals ; Antibodies, Viral/blood ; Capsid Proteins/immunology ; Female ; Hepatitis E/immunology/*veterinary/virology ; Hepatitis E virus/*immunology ; Immunization/*veterinary ; Interferon-gamma/blood ; Mice ; Mice, Inbred BALB C ; Swine ; Swine Diseases/*immunology/virology ; Vaccines, Virus-Like Particle/immunology ; Viral Hepatitis Vaccines/*immunology

In order to develop a combined live vaccine that will be used to prevent against porcine parvovirus (PPV) and Pseudorabies virus (PRV) infection, the VP2 gene of PPV was inserted into the transfer vector plasmid pG to produce the recombinant plasmid pGVP2. The plasmid pGVP2 and the genome of PRV HB98 attenuated vaccine were transfected by using lipofectamine into swine testis cells for the homologous recombination. The recombinant virus rPRV-VP2 was purified by selection of green fluorescence plaques for five cycles. 6-week-old female Kunming mice were immunized intramuscularly with attenuated PRV parent HB98 strain, commercial inactivated vaccine against PPV, recombinant virus, DMEM culture solution. The injections were repeated with an equivalent dose after 2 weeks in all of the groups, and then challenged with the virulent PRV NY strain at 7 weeks after the first immunization. The recombinant virus rPRV-VP2 was successfully generated, and the recombinant virus could effectively elicite anti-PPV and PRV antibody and significant cellular immune response as indicated by anti-PPV ELISA and HI, PRV-neutralizing assay and flow cytometry. The challenge assay indicated that recombinant virus could protect the mice against the virulent PRV challenge. These results demonstrated that the recombinant virus can be a candidate recombinant vaccine strain for the prevention of PRV and PPV.
Animals ; Antibodies, Viral ; immunology ; Antigens, Viral ; administration & dosage ; genetics ; immunology ; Capsid Proteins ; administration & dosage ; genetics ; immunology ; Female ; Gene Expression ; Genetic Vectors ; genetics ; metabolism ; Herpesvirus 1, Suid ; genetics ; metabolism ; Mice ; Parvovirus, Porcine ; genetics ; immunology ; Swine ; Swine Diseases ; immunology ; prevention & control ; virology ; Viral Vaccines ; administration & dosage ; genetics ; immunology