Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.470
Filtrar
1.
Arch Virol ; 165(3): 609-618, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31950289

RESUMO

Porcine epidemic diarrhea virus (PEDV) targets the intestinal mucosa in pigs. To protect against PEDV invasion, a mucosal vaccine is utilized effectively. In this study, we generated a recombinant adenovirus vaccine encoding the heat-labile enterotoxin B (LTB) and the core neutralizing epitope (COE) of PEDV (rAd-LTB-COE). The fusion protein LTB-COE was successfully expressed by the recombinant adenovirus in HEK293 cells, and the immunogenicity of the vaccine candidate was assessed in BALB/c mice and piglets. Three intramuscular or oral vaccinations with rAd-LTB-COE at two-week intervals induced robust humoral and mucosal immune responses. Moreover, a cell-mediated immune response was promoted in immunized mice, and the neutralizing antibody inhibited both the vaccine strain and the emerging PEDV isolate. Immunization experiments in piglets revealed that rAd-LTB-COE was immunogenic and induced good immune responses in piglets. Further studies are required to evaluate the efficacy of rAd-LTB-COE against a highly virulent PEDV challenge.


Assuntos
Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/veterinária , Vírus da Diarreia Epidêmica Suína/imunologia , Doenças dos Suínos/prevenção & controle , Vacinas Virais/imunologia , Adenoviridae/genética , Adenoviridae/imunologia , Animais , Linhagem Celular , Infecções por Coronavirus/imunologia , Enterotoxinas/genética , Enterotoxinas/imunologia , Epitopos/genética , Epitopos/imunologia , Escherichia coli/imunologia , Escherichia coli/patogenicidade , Feminino , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Vírus da Diarreia Epidêmica Suína/genética , Proteínas Recombinantes de Fusão/imunologia , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/virologia , Vacinas Virais/administração & dosagem , Vacinas Virais/uso terapêutico
2.
Vet J ; 254: 105406, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31836167

RESUMO

The tail biting management tool 'SchwIP' was developed to analyse estimated farm individual risk for tail biting and to support farmers to reduce risk. The risk factors included in SchwIP had been weighted by 61 experts regarding their strength of influence on tail biting. SchwIP was applied on 21 conventional farms throughout Germany that kept weaner pigs in closed barns. All farms were assessed with the SchwIP questionnaire and received farm-individual feedback and advice on how to reduce tail biting risk. There were no control farms with assessment only, because asking questions could raise awareness thus triggering improvements. Each farm was visited three times at 6 monthly intervals. Risk factor data collected on farms were replaced with the corresponding expert weighting, and weightings were then standardised to a range of 0 - 1 across all farms and visits. All standardised risks were summarised per farm and visit. From this, within-farm differences in farm risk sums between visit 1 and 2 (ΔRS12), 2 and 3 (ΔRS23) and 1 and 3 (ΔRS13), and the association between changes in single risk factors with ΔRS, were calculated. Farm risk sums significantly decreased from visit 1 to visit 2 and 3, respectively, but not from visit 2 to visit 3. Change in farm risk sums between visit 1 and 2 was significantly correlated with 59 factors; ΔRS23 with 54 factors; and ΔRS13 with 57 factors. Eighteen factors were significantly associated with all three ΔRS. The management tool SchwIP contributed to a reduction in estimated risk for tail biting in weaners after the first visit. There was no apparent pattern of changes in risk factors on the farms, which underlines the multifactorial nature of tail biting. Further on-farm research on tail biting risk factors and tail lesions is needed to better understand the complex relationship.


Assuntos
Criação de Animais Domésticos , Comportamento Animal , Mordeduras e Picadas/veterinária , Doenças dos Suínos/prevenção & controle , Cauda , Bem-Estar do Animal , Animais , Alemanha , Fatores de Risco , Comportamento de Redução do Risco , Comportamento Autodestrutivo/prevenção & controle , Suínos , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/psicologia , Cauda/lesões , Desmame
3.
Pol J Vet Sci ; 22(4): 639-645, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31867931

RESUMO

Since late 2011, porcine infections with highly virulent and antigenic variant of pseudorabies virus (PRV) cause great economic loss in the swine industry in China, and its emergence leads to variable protection efficacy of the commercially available PRV vaccine. In the present study, the potential cross-protective efficacy of two live virus vaccines, includ- ing a commercial vaccine, and an attenuated low pathogenic PRV variant (rPRVTJ-delTK/gE/gI) against a PRV variant Tianjing (TJ) was evaluated in piglets. Vaccination of piglets with the live vaccine Bartha-K61 could not reduce the clinical signs, and was partially efficacious in the reduc- tion of viral loads upon PRV variant TJ challenge, indicating that this live vaccine provided limited cross-protection efficacy against the PRV variant infection. Additionally, rPRVTJ-delTK/gE/gI appeared to exert some beneficial efficiency in shortening the period of clinical fever and improv- ing the growth performance of the challenged pigs. Our findings give a valuable guidance for the choice and use of PRV vaccines to control PRV variant infection in the field.


Assuntos
Herpesvirus Suídeo 1/classificação , Vacinas contra Pseudorraiva/imunologia , Pseudorraiva/prevenção & controle , Doenças dos Suínos/prevenção & controle , Animais , Linhagem Celular , Pseudorraiva/virologia , Suínos
4.
Res Vet Sci ; 127: 47-56, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31677416

RESUMO

Recent studies have questioned the effect of maternal derived antibodies (MDAs) to protect piglets against infection with influenza A virus (IAV). The lack of protection against IAV infections provided by MDAs has encouraged alternative vaccination strategies targeting young piglets in an attempt to stimulate an early antibody response. There is a lack of studies documenting the efficacy of piglet vaccination. In the present study, we monitored a group of vaccinated and non-vaccinated piglets in a Danish sow herd that initiated piglet vaccination with » dose of an inactivated swine influenza vaccine at the time of castration (day 3-4). A total of 160 piglets from 11 sows were included and either vaccinated with 0.5 mL inactivated swine influenza vaccine or sham-vaccinated. From week 0 until week 6, all included piglets were clinically examined and nasal swapped once per week and weighed at weeks 0, 3 and 6. Blood samples were collected from sows at week 0 and from piglets at week 3. Vaccination of piglets had limited effect on clinical signs, body weight, antibody development and viral shedding, within the first 6 weeks of life. At least 50% of all pigs of each treatment group tested positive for IAV at week 2, and very early onset of IAV shedding was observed. In total, 18 pigs were IAV positive in nasal swabs for more than one consecutive sampling time indicating prolonged shedding and 14 pigs were IAV positive with negative samplings in between indicating re-infection with the same IAV strain.


Assuntos
Vírus da Influenza A/efeitos dos fármacos , Vacinas contra Influenza/farmacologia , Infecções por Orthomyxoviridae/veterinária , Doenças dos Suínos/prevenção & controle , Vacinação/veterinária , Animais , Anticorpos Antivirais/sangue , Formação de Anticorpos , Dinamarca , Vírus da Influenza A/fisiologia , Vacinas contra Influenza/administração & dosagem , Infecções por Orthomyxoviridae/prevenção & controle , Infecções por Orthomyxoviridae/virologia , Suínos , Doenças dos Suínos/virologia , Vacinas de Produtos Inativados/administração & dosagem , Vacinas de Produtos Inativados/farmacologia , Eliminação de Partículas Virais
5.
Vet Microbiol ; 239: 108492, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31767065

RESUMO

Swine influenza A virus (IAV-S) infections are a major cause of economic losses for the swine industry. The vast genetic and antigenic diversity often results in mismatch between the vaccine and field strains, necessitating frequent updates of vaccines. Inactivated IAV-S vaccines are of questionable efficacy. Intra-nasally administered live vaccines are more effective but are associated with safety concerns. The objective of this study was to develop a first-generation vaccine which combines the safety and efficacy advantages of inactivated and attenuated vaccines respectively. The approach targeted fragmentation of viral nucleic acids while preserving structure. Hence, cultures of influenza A/CA/04/09 H1N1 were exposed to 44 °C for 10 min. to reversibly denature the capsid, followed by RNase treatment to digest the genomic RNA and then refolded at lower temperatures. As targeted, treated virions retained an intact structure and were not detected in the first passage in infected cells. To improve intra-nasal delivery of the vaccine antigen, the vaccine antigen was delivered in porcine lung surfactant. Both the treated vaccine alone or vaccine in combination with the surfactant elicited strong anti-HA and virus neutralizing antibodies, protection against viral shedding and lung lesions in 3-week-old piglets. There were no significant differences between the groups. Vaccine viral replication was not detected in the vaccinated pigs. The described approach can advance current immunization practices against swine influenza viruses due to the relative simplicity, high efficacy and safety and ease of adaptation to newly emerging field strains.


Assuntos
Vírus da Influenza A/imunologia , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/imunologia , Infecções por Orthomyxoviridae/veterinária , Tensoativos/administração & dosagem , Vacinas Atenuadas/imunologia , Vacinas de Produtos Inativados/imunologia , Administração Intranasal/veterinária , Animais , Anticorpos Antivirais/sangue , Temperatura Alta , Infecções por Orthomyxoviridae/prevenção & controle , Infecções por Orthomyxoviridae/virologia , Suínos , Doenças dos Suínos/prevenção & controle , Doenças dos Suínos/virologia , Vacinas Atenuadas/administração & dosagem , Vacinas de Produtos Inativados/administração & dosagem
6.
Vet Microbiol ; 237: 108401, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31585639

RESUMO

Influenza results in significant economic loss in the swine industry each year. A broadly protective swine influenza vaccine would have the dual benefit of protecting pigs from influenza A viruses (IAVs) and limiting their possible zoonotic transmission to humans. In this study, we developed polyanhydride nanoparticles-based swine influenza vaccine (KAg + CpG-nanovaccine) co-encapsulating inacticated/killed soluble antigen (KAg) and Toll-like receptor (TLR)-9 agonist (CpG-ODN). The immunogenicity and protective efficacy of KAg + CpG-nanovaccine was compared with KAg vaccine containing five-times greater quantity of antigens following heterologous virus challenge. Prime-boost intranasally delivered KAg + CpG-nanovaccine induced significantly higher levels of cross-reactive antigen-specific IgA antibody responses in the nasal cavity, greater lymphoproliferative response in peripheral blood mononuclear cells (PBMCs), and higher IFN-γ secretion during antigen-induced recall responses of PBMCs and tracheobronchial lymph nodes cells compared to those immunized with KAg alone. Importantly, KAg + CpG-nanovaccine provided better protective efficacy through a significant reduction in influenza-induced fever, 16-fold reduction of nasal virus shedding and 80-fold reduction in lung virus titers compared to those immunized with soluble KAg. Our results indicated that CpG-ODN-adjuvanted polyanhydride nanovaccine can induce higher mucosal antibody and cellular immune responses in pigs; and provide better protection as compared with intranasally delivered soluble KAg.


Assuntos
Vacinas contra Influenza/imunologia , Oligodesoxirribonucleotídeos/farmacologia , Infecções por Orthomyxoviridae/veterinária , Doenças dos Suínos/prevenção & controle , Adjuvantes Imunológicos , Administração Intranasal , Animais , Anticorpos Antivirais , Antígenos Virais/imunologia , Feminino , Imunidade nas Mucosas , Imunoglobulina A/imunologia , Interferon gama/metabolismo , Leucócitos Mononucleares , Masculino , Nanoestruturas , Oligodesoxirribonucleotídeos/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Polianidridos , Suínos , Vacinas de Produtos Inativados/imunologia
7.
BMC Vet Res ; 15(1): 342, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31619295

RESUMO

BACKGROUND: The objective of this study was to assess the efficacy of a trivalent vaccine mixture and compare it to the respective monovalent vaccines against Mycoplasma hyopneumoniae, porcine circovirus type 2 (PCV2), and porcine reproductive and respiratory syndrome virus (PRRSV). RESULTS: Pigs that were triple challenged with M. hyopneumoniae, PCV2, and PRRSV following vaccination with the trivalent vaccine mixture exhibited a significantly better growth performance when compared to unvaccinated and challenged pigs. A statistical difference was not found when comparing pig populations which were vaccinated with the trivalent vaccine followed by a triple challenge and pigs vaccinated with monovalent M hyopneumoniae vaccine followed by mycoplasmal single challenge in the following areas: M. hyopneumoniae nasal shedding, the number of M. hyopneumoniae-specific interferon-γ secreting cells (IFN-γ-SC), and mycoplasmal lung lesion scores. Pigs vaccinated with the trivalent vaccine mixture followed by a triple challenge resulted in a similar reduction of PCV2 viremia, an increase in the number of PCV2-specific IFN-γ-SC and reduction in interstitial lung lesion scores when compared to pigs vaccinated with a PCV-2 vaccine and challenged with PCV2 only. Lastly, there was a significant difference in the reduction of PRRSV viremia, an increase in PRRSV-specific IFN-γ-SC and a reduction of interstitial lung lesion scores between pigs vaccinated with the trivalent vaccine mixture followed by a triple challenge and pigs vaccinated with a monovalent PRRSV vaccine followed by PRRSV challenge only. CONCLUSION: The trivalent vaccine mixture was efficacious against a triple challenge of M. hyopneumoniae, PCV2, and PRRSV. The trivalent vaccine mixture, however, did not result in equal protection when compared against each respective monovalent vaccine, with the largest vaccine occurring within PRRSV.


Assuntos
Circovirus/imunologia , Mycoplasma hyopneumoniae/imunologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , Doenças dos Suínos/prevenção & controle , Vacinação/veterinária , Animais , Vacinas Bacterianas/imunologia , Infecções por Circoviridae/imunologia , Infecções por Circoviridae/prevenção & controle , Feminino , Masculino , Pneumonia Suína Micoplasmática/imunologia , Pneumonia Suína Micoplasmática/prevenção & controle , Síndrome Respiratória e Reprodutiva Suína/imunologia , Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Sus scrofa , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/microbiologia , Doenças dos Suínos/virologia , Vacinas Combinadas/administração & dosagem , Vacinas Combinadas/imunologia , Vacinas Virais/imunologia
8.
Infect Immun ; 87(12)2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31548316

RESUMO

Swine erysipelas is caused by the Gram-positive pathogen Erysipelothrix rhusiopathiae The swine erysipelas live vaccine in Japan, the E. rhusiopathiae Koganei 65-0.15 strain (Koganei), has been reported to cause arthritis and endocarditis. To develop a vaccine with increased safety, we used a virulent Fujisawa strain to construct transposon mutants for a total of 651 genes, which covered 38% of the coding sequence of the genome. We screened the mutants for attenuation by inoculating mice with 108 CFU of each mutant and subsequently assessed protective capability by challenging the surviving mice with 103 CFU (102 times the 50% lethal dose) of the Fujisawa strain. Of the 23 attenuated mutants obtained, 6 mutants were selected and evaluated for protective capability in pigs by comparison to that of the Koganei strain. A mutant in the ERH_0432 (tagF) gene encoding a putative CDP-glycerol glycerophosphotransferase was found to be highly attenuated and to induce humoral and cell-mediated immune responses in conventional pigs. An in-frame deletion mutant of the gene, the Δ432 mutant, was constructed, and attenuation was further confirmed in germfree piglets; three of four piglets subcutaneously inoculated with 109 CFU of the Δ432 mutant showed no apparent clinical symptoms, whereas all four of the Koganei-inoculated piglets died 3 days after inoculation. It was confirmed that conventional pigs inoculated orally or subcutaneously with the Δ432 strain were almost completely protected against lethal challenge infection. Thus, the tagF homolog mutant of E. rhusiopathiae represents a safe vaccine candidate that can be administered via the oral and subcutaneous routes.


Assuntos
Vacinas Bacterianas/imunologia , Infecções por Erysipelothrix/prevenção & controle , Erysipelothrix/genética , Erysipelothrix/imunologia , Doenças dos Suínos/prevenção & controle , Transferases (Outros Grupos de Fosfato Substituídos)/genética , Animais , Elementos de DNA Transponíveis/genética , Erysipelothrix/patogenicidade , Infecções por Erysipelothrix/imunologia , Feminino , Camundongos , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/microbiologia , Vacinas Atenuadas/imunologia
9.
J Anim Sci ; 97(10): 4152-4159, 2019 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-31504579

RESUMO

In pig production, efficiency is benefiting from uniform growth in pens resulting in single deliveries from a pen of possibly all animals in the targeted weight range. Abnormalities, like pneumonia or aberrant growth, reduce production efficiency as it reduces the uniformity and might cause multiple deliveries per batch and pigs delivered with a low meat yield or outside the targeted weight range. Early identification of pigs prone to develop these abnormalities, for example, at the onset of the growing-finishing phase, would help to prevent heterogeneous pens through management interventions. Data about previous production cycles at the farm combined with data from the piglet's own history may help in identifying these abnormalities. The aim of this study, therefore, was to predict at the onset of the growing-finishing phase, that is, at 3 mo in advance, deviant pigs at slaughter with a machine-learning technique called boosted trees. The dataset used was extracted from the farm management system of a research center. It contained over 70,000 records of individual pigs born between 2004 and 2016, including information on, for example, offspring, litter size, transfer dates between production stages, their respective locations within the barns, and individual live-weights at several production stages. Results obtained on an independent test set showed that at a 90% specificity rate, the sensitivity was 16% for low meat percentage, 20% for pneumonia and 36% for low lifetime growth rate. For low lifetime growth rate, this meant an almost three times increase in positive predictive value compared to the current situation. From these results, it was concluded that routine performance information available at the onset of the growing-finishing phase combined with data about previous production cycles formed a moderate base to identify pigs prone to develop pneumonia (AUC > 0.60) and a good base to identify pigs prone to develop growth aberrations (AUC > 0.70) during the growing-finishing phase. The mentioned information, however, was not a sufficient base to identify pigs prone to develop low meat percentage (AUC < 0.60). The shown ability to identify growth aberrations and pneumonia can be considered a good first step towards the development of an early warning system for pigs in the growing-finishing phase.


Assuntos
Ração Animal/análise , Abrigo para Animais/normas , Pneumonia/veterinária , Carne Vermelha/análise , Doenças dos Suínos/prevenção & controle , Criação de Animais Domésticos , Animais , Composição Corporal , Meio Ambiente , Feminino , Aprendizado de Máquina , Masculino , Pneumonia/prevenção & controle , Suínos , Árvores
10.
Aust Vet J ; 97(11): 447-451, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31475336

RESUMO

OBJECTIVE: Australia is currently regarded as free of classical swine fever (CSF), a highly contagious disease of pigs caused by a pestivirus. This study aimed to provide additional evidence that the Victorian domestic pig population is free of CSF. DESIGN: A structured representative sero-prevalence survey of Victorian domestic pigs at slaughter. METHOD: Three-hundred and ninety-one pigs from 23 holdings were sampled at the time of slaughter between March 2016 and October 2017. RESULTS: All samples were negative for CSF virus Ab on ELISA. Because of uncertainty in the sensitivity of the CSF Ab ELISA, estimates of the true prevalence of CSF were calculated using Bayesian methods. The median and upper bound of the 95% credible intervals for the true prevalence of CSF was zero when the diagnostic sensitivity of the CSF Ab ELISA was assumed to range from 0.75 to 0.95. CONCLUSION: These results provide evidence that the population of domestic pigs in Victoria in 2016-2017 was free of CSF.


Assuntos
Peste Suína Clássica/epidemiologia , Peste Suína Clássica/prevenção & controle , Erradicação de Doenças , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/prevenção & controle , Animais , Peste Suína Clássica/sangue , Vírus da Febre Suína Clássica/isolamento & purificação , Ensaio de Imunoadsorção Enzimática/veterinária , Prevalência , Sus scrofa , Suínos , Doenças dos Suínos/sangue , Doenças dos Suínos/virologia , Vitória/epidemiologia
11.
Animal ; 13(12): 3031-3040, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31475656

RESUMO

On many Australian commercial pig farms, groups of growing pigs are mass-medicated through their drinking water with selected antimicrobials for short periods to manage herd health. However, delivery of medication in drinking water cannot be assumed to deliver an equal dose to all animals in a group. There is substantial between-animal variability in systemic exposure to an antimicrobial (i.e. the antimicrobial concentration in plasma), resulting in under-dosing or over-dosing of many pigs. Three sources of this between-animal variability during a water medication dosing event are differences in: (1) concentration of the active constituent of the antimicrobial product in water available to pigs at drinking appliances in each pen over time, (2) medicated water consumption patterns of pigs in each pen over time, and (3) pharmacokinetics (i.e. oral bioavailability, volume of distribution and clearance between pigs and within pigs over time). It is essential that factors operating on each farm that influence the range of systemic exposures of pigs to an antimicrobial are factored into antimicrobial administration regimens to reduce under-dosing and over-dosing.


Assuntos
Antibacterianos/administração & dosagem , Água Potável , Doenças dos Suínos/prevenção & controle , Animais , Suínos
12.
Vet Microbiol ; 236: 108374, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31500734

RESUMO

Foot-and-mouth disease (FMD) is a highly contagious disease and causes economic damage at a national level. In particular, the type O FMD virus (FMDV) is a serotype that causes FMD outbreaks most frequently in the world. In recent years, Southeast Asia (SEA), Middle East-South Asia (ME-SA), and Cathay topotype-mediated FMD are prevalent in Asia, among which the SEA and ME-SA topotypes cause a majority of the outbreaks. The SEA topotype virus is more likely to infect both cattle and pigs simultaneously, thereby resulting in more severe damages; thus, it is necessary to study the protection ability of the candidate vaccines of this topotype after immunization. In this study, an experimental vaccine for pigs was produced using a vaccine strain that contains the structural protein of the O Taiwan97 strain, which was derived from the Cathay topotype, and its effect was evaluated. In the immunization test in pigs and cattle, the antibody titers were found to be elevated two weeks after immunization and very high titers of neutralizing antibodies were formed after four weeks. After the second inoculation, very high titers of neutralizing antibodies were produced in both species in the fourth week after immunization, and the antibodies maintained for up to six months and three months in cattle and pigs, respectively. No significant immunological difference in antibody production was observed in cattle and pigs. This study confirmed that complete protection from the challenge of the SEA topotype virus (O/Jincheon/SKR/2014), although the antibody titers against O/Jincheon/SKR/2014 strain were not that high, was achieved through immunization with the newly developed Cathay topotype vaccine in pigs.


Assuntos
Vírus da Febre Aftosa/classificação , Febre Aftosa/prevenção & controle , Doenças dos Suínos/prevenção & controle , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/sangue , Febre Aftosa/epidemiologia , Febre Aftosa/virologia , Camundongos , Camundongos Endogâmicos ICR , República da Coreia/epidemiologia , Suínos , Doenças dos Suínos/virologia , Eliminação de Partículas Virais
13.
Vet Microbiol ; 235: 270-279, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31383312

RESUMO

Lawsonia intracellularis is an obligate intracellular microorganism and the causative agent of porcine proliferative enteropathy. Due to its obligate intracellular nature, characterization of antigens and proteins involved in host-pathogen interaction and immune recognition have been difficult to achieve using conventional microbiological techniques. In this work, we used 2-dimensional gel electrophoresis coupled with Western-immunoblotting, mass spectrometry and bioinformatics to identify bacterial proteins that interact in vitro with pig intestinal cells (IPEC-1), have immunogenic properties and the potential to be used as subunit vaccine antigens. We detected eleven immunogenic bacterial proteins from which fliC (LI0710), LI1153 (annotated by NCBI as Putative protein N), and LI0649 (annotated as autotransporter) were predicted to be expressed on the outer membrane while LI0169 (oppA; annotated as ABC dipeptide transport system) was predicted to be periplasmic with a transmembrane domain forming a central pore through the plasma membrane. Genes coding for these four proteins were cloned and expressed in Escherichia coli and the corresponding recombinant proteins were purified using affinity chromatography. Porcine hyperimmune serum against whole Lawsonia lysate established that all four recombinant proteins were immunogenic. Further, rabbit hyperimmune sera generated against the vaccine strain of L. intracellularis and rabbit serum specific for each recombinant protein showed an inhibitory effect on the attachment and penetration of live, avirulent L. intracellularis, thus indicating that each protein is a potential neutralizing antibody target and a candidate for subunit vaccine formulation.


Assuntos
Anticorpos Antibacterianos/imunologia , Anticorpos Neutralizantes/imunologia , Proteínas de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Infecções por Desulfovibrionaceae/veterinária , Lawsonia (Bactéria)/imunologia , Animais , Proteínas de Bactérias/genética , Western Blotting , Linhagem Celular , Biologia Computacional , Infecções por Desulfovibrionaceae/imunologia , Infecções por Desulfovibrionaceae/prevenção & controle , Feminino , Intestinos/citologia , Intestinos/microbiologia , Espectrometria de Massas , Proteômica , Coelhos , Proteínas Recombinantes/imunologia , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/microbiologia , Doenças dos Suínos/prevenção & controle , Vacinas de Subunidades/imunologia
14.
Food Funct ; 10(8): 5152-5165, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31373594

RESUMO

The aim of this study was to investigate the effects of dietary ß-hydroxy-ß-methylbutyrate (HMB) on lipopolysaccharide (LPS)-induced muscle atrophy and to investigate the mechanisms involved. Sixty pigs (21 ± 2 days old, 5.86 ± 0.18 kg body weight) were used in a 2 × 3 factorial design and the main factors included diet (0, 0.60%, or 1.20% HMB) and immunological challenge (LPS or saline). After 15 d of treatment with LPS and/or HMB, growth performance, blood parameters, and muscle protein degradation rate were measured. The results showed that in LPS-injected pigs, 0.60% HMB supplementation increased the average daily gain and average daily feed intake and decreased the feed : gain ratio (P < 0.05), with a concurrent increase of lean percentage. Moreover, 0.60% HMB supplementation decreased the serum concentrations of blood urea nitrogen, IL-1ß, and TNF-α and the rate of protein degradation as well as cell apoptosis in selected muscles (P < 0.05). In addition, dietary HMB supplementation (0.60%) regulated the expression of genes involved in mitochondrial biogenesis and increased the phosphorylation of Akt and Forkhead Box O3a (FoxO3a) in selected muscles, accompanied by decreased protein expression of muscle RING finger 1 and muscle atrophy F-box. These results indicate that HMB may exert protective effects against LPS-induced muscle atrophy by normalizing the Akt/FoxO3a axis that regulates ubiquitin proteolysis and by improving mitochondrial biogenesis.


Assuntos
Proteína Forkhead Box O3/metabolismo , Mitocôndrias/efeitos dos fármacos , Proteínas Musculares/metabolismo , Atrofia Muscular/veterinária , Proteínas Proto-Oncogênicas c-akt/metabolismo , Doenças dos Suínos/prevenção & controle , Valeratos/administração & dosagem , Ração Animal/análise , Animais , Feminino , Proteína Forkhead Box O3/genética , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Lipopolissacarídeos/efeitos adversos , Masculino , Mitocôndrias/metabolismo , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Atrofia Muscular/induzido quimicamente , Atrofia Muscular/metabolismo , Atrofia Muscular/prevenção & controle , Biogênese de Organelas , Proteólise/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/genética , Transdução de Sinais/efeitos dos fármacos , Suínos , Doenças dos Suínos/induzido quimicamente , Doenças dos Suínos/genética , Doenças dos Suínos/metabolismo
15.
J Vet Sci ; 20(4): e32, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31364317

RESUMO

The recent emergence and re-emergence of porcine epidemic diarrhea virus (PEDV) underscore the urgent need for the development of novel, safe, and effective vaccines against the prevailing strain. In this study, we generated a cold-adapted live attenuated vaccine candidate (Aram-P29-CA) by short-term passage of a virulent PEDV isolate at successively lower temperatures in Vero cells. Whole genome sequencing identified 12 amino acid changes in the cold-adapted strain with no insertions and deletions throughout the genome. Animal inoculation experiments confirmed the attenuated phenotype of Aram-P29-CA virus in the natural host. Pregnant sows were orally administered P29-CA live vaccines two doses at 2-week intervals prior to parturition, and the newborn piglets were challenged with the parental virus. The oral homologous prime-boost vaccination of P29-CA significantly improved the survival rate of the piglets and notably mitigated the severity of diarrhea and PEDV fecal shedding after the challenge. Furthermore, strong antibody responses to PEDV were detected in the sera and colostrum of immunized sows and in the sera of their offspring. These results demonstrated that the cold-adapted attenuated virus can be used as a live vaccine in maternal vaccination strategies to provide durable lactogenic immunity and confer passive protection to litters against PEDV.


Assuntos
Infecções por Coronavirus/veterinária , Vírus da Diarreia Epidêmica Suína/imunologia , Doenças dos Suínos/prevenção & controle , Vacinas Virais/farmacologia , Animais , Animais Recém-Nascidos , Temperatura Baixa , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/virologia , Feminino , Genótipo , Vírus da Diarreia Epidêmica Suína/genética , Gravidez , Distribuição Aleatória , Sus scrofa , Suínos , Doenças dos Suínos/virologia , Vacinas Atenuadas/farmacologia , Células Vero
16.
J Vet Sci ; 20(4): e35, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31364320

RESUMO

The major immunogenic protein capsid (Cap) of porcine circovirus type 2 (PCV2) is critical to induce neutralizing antibodies and protective immune response against PCV2 infection. This study was conducted to investigate the immune response of recombinant adenovirus expressing PCV2b Cap and C-terminal domain of Yersinia pseudotuberculosis invasin (Cap-InvC) fusion protein in pigs. The recombinant adenovirus rAd-Cap-InvC, rAd-Cap and rAd were generated and used to immunize pigs. The phosphate-buffered saline was used as negative control. The specific antibodies levels in rAd-Cap-InvC and ZJ/C-strain vaccine groups were higher than that of rAd-Cap group (p < 0.05), and the neutralization antibody titer in rAd-Cap-InvC group was significantly higher than those of other groups during 21-42 days post-immunization (DPI). Moreover, lymphocyte proliferative level, interferon-γ and interleukin-13 levels in rAd-Cap-InvC group were increased compared to rAd-Cap group (p < 0.05). After virulent challenge, viruses were not detected from the blood samples in rAd-Cap-InvC and ZJ/C-strain vaccine groups after 49 DPI. And the respiratory symptom, rectal temperature, lung lesion and lymph node lesion were minimal and similar in the ZJ/C-strain and rAd-Cap-InVC groups. In conclusion, our results demonstrated that rAd-Cap-InvC was more efficiently to stimulate the production of antibody and protect pigs from PCV2 infection. We inferred that InvC is a good candidate gene for further development and application of PCV2 genetic engineering vaccine.


Assuntos
Vacinas contra Adenovirus/administração & dosagem , Proteínas do Capsídeo/imunologia , Infecções por Circoviridae/veterinária , Circovirus/imunologia , Imunização/veterinária , Doenças dos Suínos/prevenção & controle , Adesinas Bacterianas/genética , Adesinas Bacterianas/imunologia , Animais , Infecções por Circoviridae/prevenção & controle , Infecções por Circoviridae/virologia , Feminino , Proteínas Recombinantes/imunologia , Sus scrofa , Suínos , Doenças dos Suínos/virologia , Vacinas Sintéticas/administração & dosagem , Yersinia pseudotuberculosis/genética
17.
J Vet Sci ; 20(4): e42, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31364326

RESUMO

Foot-and-mouth disease (FMD) is an acute epidemic that spreads rapidly among cattle and pigs. In 2014, in Korea, despite enforced vaccination, the type O Southeast Asia (SEA) topotype viruses (Mya-98 lineage) infected mainly cattle and pigs simultaneously, thereby causing enormous damage. If a vaccine that is completely protective against this FMD virus is developed and used, it can become a very important preventive measure in Asia, which is where this type of virus mainly circulates. The SEA topotype has been steadily evolving and transforming into new variations since it became epidemic in Asia. Therefore, it became necessary to develop a new vaccine that could provide protection against the FMD virus strain that was responsible for the 2014-2015 outbreak in Korea. This study aimed to develop a vaccine that would provide complete protection against the SEA topotype FMD virus to control sporadic FMD outbreaks, which occur despite the enforcement of vaccination, and to completely prevent virus shedding, thereby preventing the virus from spreading. The vaccine candidate virus developed in this study showed low pathogenicity and can be distinguished from the wild-type FMD virus strain. The developed vaccine was able to protect mice from SEA and Middle East-South Asia topotype virus strains and induced high titers of antibodies against both virus strains in pigs, thereby confirming the sufficiency of its protective function. In particular, the results of the SEA topotype virus challenge test in pigs revealed that perfect immunity was created in the vaccinated pigs, without virus shedding and viremia.


Assuntos
Vírus da Febre Aftosa/imunologia , Febre Aftosa/prevenção & controle , Doenças dos Suínos/prevenção & controle , Vacinas Virais/farmacologia , Animais , Febre Aftosa/imunologia , Febre Aftosa/virologia , República da Coreia , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/virologia
18.
Theriogenology ; 137: 82-87, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31285050

RESUMO

Protecting boar studs and their clients from emerging infectious disease first involves effective biosecurity measures to keep a disease out that was not present, and second, early identification and ceasing semen distribution prior to disseminating infectious disease. Experiences in the field can best guide us as to what has been effective. Circumstances in North America in the period of 1999-2004 resulted in numerous PRRS virus (Porcine Reproductive and Respiratory Syndrome) negative boar studs becoming infected and disseminating virus to sow farms. Earlier detection methods were needed, and withholding of semen pending negative test results became standard. To accomplish this, diagnostic labs complied with industry requests for same day testing. At the same time, research efforts helped clarify the major routes of PRRS virus introduction into the farms. The risk of fomites and aerosol spread became viewed as major risks. Addressing issues with people and supply entry alone did not eliminate new virus entry. The implementation of air filtration during 2005-2008 had a major impact on the rate of new virus introductions into boar studs after other measures alone were unsuccessful. Risks exposed with the introduction of PED virus (Porcine Epidemic Diarrhea) into North America further highlighted other risk factors such as feed ingredients, trailer sanitation, and the presence of clear physical barriers. The successful adaptation of testing procedures, combined with biosecurity procedures including air filtration, has made the incidence of infectious disease introduction extremely rare in North American boar studs over the last decade. While survivability of infectious disease agents can vary in different materials or in the air, successful protocols should be applied and adjusted as needed to accommodate new information or risks. Cleary defined physical barriers for people and animal entry and exit, sanitization and/or down time on incoming supplies, risk mitigation and testing of feed ingredients, and filtration have been keys to changing the incidence of emerging infectious disease introduction into boar studs.


Assuntos
Criação de Animais Domésticos/métodos , Doenças Transmissíveis Emergentes/veterinária , Abrigo para Animais/normas , Doenças dos Suínos/prevenção & controle , Animais , Doenças Transmissíveis Emergentes/prevenção & controle , Feminino , Masculino , América do Norte , Sêmen/virologia , Suínos , Doenças dos Suínos/transmissão , Doenças dos Suínos/virologia
19.
Vet Microbiol ; 235: 1-9, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31282365

RESUMO

Oral immunization is a commonly employed route for inducing local immunity. However, the application of oral immunization is limited by the short-term persistence of immunity, particularly for inactivated viruses. The ultimate goal for mucosal vaccination is to stimulate protective immunological memory. In the intestine, long-term persistence of immunity is related to CD4+CD8+ memory T-cells. In this study, piglets were orally immunized with Bacillus subtilis spores (B.s) plus whole inactivated porcine epidemic diarrhea virus (PEDV WIV), followed by booster oral immunization. Initially, the results showed that B.s plus PEDV WIV enhanced the anti-PEDV capability on mucosal surfaces, as evidenced by plaque reduction neutralization tests in serum and intestinal fluid. Elevated antigen-specific IgG titers in the serum and IgA titers in saliva, feces and nasal washing liquid were also observed. Meanwhile, B.s plus PEDV WIV increased the area of Peyer's patches and the number of intraepithelial lymphocytes in the ileum of piglets. Similarly, the percentage of CD4+CD8+ memory T-cells were upregulated and proliferation ability of antigen-specific memory T-cell was strengthened in intestinal mucosal-associated lymphocytes, which was accompanied with increased expression of CCR9 after oral immunization with B.s plus PEDV WIV. In addition, the activation of memory T-cells is correlated with the increased mRNA expression of Toll-like receptor 2 and 4, as well as interleukin-6 and induced by B.s. Collectively, the study provided further insight into the potential immunopotentiator ability of B.s to assist PEDV WIV in the potentiation of immunity by upregulating memory CD4+CD8+ T cells via oral immunization.


Assuntos
Bacillus subtilis/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Memória Imunológica , Mucosa Intestinal/imunologia , Vírus da Diarreia Epidêmica Suína/imunologia , Administração Oral , Animais , Anticorpos Antivirais/sangue , Imunização/métodos , Imunização Secundária , Imunoglobulina G/sangue , Esporos/imunologia , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/prevenção & controle , Regulação para Cima , Vacinas de Produtos Inativados/imunologia
20.
Vet Microbiol ; 235: 86-92, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31282383

RESUMO

Although PCV2 infections generally cause mild disease in pigs, concurrent co-infections with other pathogens can damage the immune system and cause more severe diseases, collectively termed porcine circovirus associated diseases (PCVAD). Involvement of porcine parvovirus (PPV, a common cause of reproductive failure in naïve dams) in PCVAD caused by PCV2, has been reported. As this co-infection can be difficult to eliminate, there is a critical need to develop an effective vaccine to protect against PPV or synergistic effects of PCV2 and PPV under field conditions. In this study, we designed chimeric PCV2 virus-like particles (cVLPs) displaying a B-cell epitope derived from PPV1 structural protein around the surface of the 2-fold axes of PCV2 VLPs, based on 3D-structure analysis of the PCV2 capsid. The cVLPs were successfully prepared, verified by transmission electron microscopy and chromatography, with robust antibody titers against PCV2 and PPV1 produced in mice and guinea pigs. In addition, in guinea pigs challenged with 106 TCID50 PCV2, cVLPs conferred more effective immune protection (based on viral load) than a commercial PCV2 vaccine. Finally, antibody responses and immune protection against PPV were also evaluated. In guinea pigs vaccinated with cVLPs, although PPV antibodies detected by a hemagglutination inhibition (HI) assay appeared later after vaccination in the PCV2 cVLPs group than in the commercial PPV vaccine group, there were fewer PPV genomic DNA copies in the PCV2 cVLPs group than in a PBS group. In conclusion, guinea pigs vaccinated with cVLPs developed effective protective immunity against PCV2 challenge, with some protective immunity against PPV. This study provided valuable research data to pursue molecular design of chimeric epitopes PCV2 VLPs.


Assuntos
Infecções por Circoviridae/veterinária , Coinfecção/veterinária , Epitopos de Linfócito B/imunologia , Imunidade Humoral , Infecções por Parvoviridae/veterinária , Vacinas Virais/imunologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Linfócitos B/imunologia , Infecções por Circoviridae/imunologia , Infecções por Circoviridae/prevenção & controle , Circovirus/imunologia , Coinfecção/virologia , Feminino , Cobaias , Camundongos , Infecções por Parvoviridae/imunologia , Infecções por Parvoviridae/prevenção & controle , Parvovirus Suíno/imunologia , Suínos , Doenças dos Suínos/prevenção & controle , Doenças dos Suínos/virologia , Vacinas Atenuadas/imunologia , Vacinas de Partículas Semelhantes a Vírus/imunologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA