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1.
Vet Immunol Immunopathol ; 213: 109887, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31307668

RESUMO

Chlamydia abortus produces ovine enzootic abortion (OEA). Symptoms are not observed until the organism colonises the placenta, eventually causing abortion. Infected animals become carriers and will shed the organism in the following oestruses. This process suggests that sex hormones might play an important role in the physiopathology of OEA, affecting the success of chlamydial clearance and also jeopardising the effectiveness of vaccination. However, the mechanisms through which sex hormones are involved in chlamydial pathogenicity remain unclear. The aim of this study, therefore, was to determine the effect of progesterone on the immune response against C. abortus and on the protection conferred by an experimental inactivated vaccine in sheep. Eighteen sheep were ovariectomised and divided into four groups: vaccinated and progesterone-treated (V-PG), vaccinated and non-treated (V-NT), non-vaccinated and non-treated (NV-NT) and non-vaccinated and progesterone-treated sheep (NV-PG). Animals from both PG groups were treated with commercial medroxyprogesterone acetate impregnated intravaginal sponges before and during the vaccination (V-PG) or just before challenge (NV-PG). The animals from both V groups were subcutaneously immunised with an experimental inactivated vaccine, which was seen to confer high protection in previous studies. All sheep were challenged intratracheally with C. abortus strain AB7 and were sacrificed on day 8 post-infection. Morbidity was measured as the variation in rectal temperature and samples of sera were collected for antibody and cytokine (IFN-γ and IL-10) analysis by commercial ELISA. In addition, lung and lymph node samples were collected for chlamydial detection by qPCR and for histopathological and immunohistochemical analyses. Sheep from the V-PG group showed less severe or no lesions and lower morbidity than the other groups. They also had the highest abundance of regulatory T-cells. The sheep from V-NT also manifested high antibody levels against C. abortus and less severe lesions than those observed in non-vaccinated sheep, which showed high morbidity, low antibody levels and severe lesions, especially in NV-NT. These results confirm the effectiveness of the experimental vaccine employed and suggest that progesterone could enhance the effect.


Assuntos
Vacinas Bacterianas/uso terapêutico , Infecções por Chlamydia/veterinária , Imunidade Humoral , Progesterona/administração & dosagem , Doenças dos Ovinos/imunologia , Aborto Animal/imunologia , Aborto Animal/prevenção & controle , Animais , Anticorpos Antibacterianos/sangue , Vacinas Bacterianas/imunologia , Chlamydia/imunologia , Infecções por Chlamydia/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Ovinos , Doenças dos Ovinos/microbiologia , Vacinas de Produtos Inativados/imunologia , Vacinas de Produtos Inativados/uso terapêutico
2.
BMC Vet Res ; 15(1): 223, 2019 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-31266499

RESUMO

BACKGROUND: The role played by the humoral immune response in animals vaccinated against a mycobacterial disease such as paratuberculosis, is not well understood. Sheep vaccinated against Mycobacterium avium subsp. paratuberculosis (MAP) can still become infected and in some cases succumb to clinical disease. The strength and location of the humoral immune response following vaccination could contribute to the ability of sheep to clear MAP infection. We examined the peripheral antibody response along with the localised humoral response at the site of paratuberculosis infection, the ileum, to better understand how this contributes to MAP infection of sheep following vaccination and exposure. RESULTS: Through assessing MAP specific serum IgG1 and IgG levels we show that the timing and strength of the humoral immune response directly relates to prevention of infection following vaccination. Vaccinated sheep that subsequently became infected had significantly reduced levels of MAP specific serum IgG1 early after vaccination. In contrast, vaccinated sheep that did not subsequently become infected had significantly elevated MAP specific serum IgG1 following vaccination. Furthermore, at 12 months post MAP exposure, vaccinated and subsequently uninfected sheep had downregulated expression of genes related to the humoral response in contrast to vaccinated infected sheep where expression levels were upregulated. CONCLUSIONS: The timing and strength of the humoral immune response following vaccination against paratuberculosis in sheep directly relates to subsequent infection status. An initial strong IgG1 response following vaccination was crucial to prevent infection. Additionally, vaccinated uninfected sheep were able to modulate that response following apparent MAP clearance, unlike vaccinated infected animals where there was apparent dysregulation of the humoral response, which is associated with progression to clinical disease.


Assuntos
Vacinas Bacterianas/imunologia , Paratuberculose/imunologia , Doenças dos Ovinos/imunologia , Animais , Anticorpos Antibacterianos/sangue , Vacinas Bacterianas/administração & dosagem , Imunidade Humoral , Imunoglobulina G/sangue , Masculino , Mycobacterium avium subsp. paratuberculosis/imunologia , Paratuberculose/prevenção & controle , Ovinos , Doenças dos Ovinos/microbiologia , Carneiro Doméstico , Vacinação/veterinária
3.
Vet Parasitol ; 270: 31-39, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31213239

RESUMO

Breeding for resistance to gastrointestinal nematodes (GIN) in sheep relies largely on the use of worm egg counts (WEC) to identify animals that are able to resist infection. As an alternative to such measures of parasite load we aimed to develop a method to identify animals showing resistance to GIN infection based on the impact of the infection on blood parameters. We hypothesized that blood parameters may provide a measure of infection level with a blood-feeding parasite through perturbation of red blood cell parameters due to feeding behaviour of the parasite, and white blood cell parameters through the mounting of an immune response in the host animal. We measured a set of blood parameters in 390 sheep that had been exposed to an artificial regime of repeated challenges with Trichostrongylus colubriformis followed by Haemonchus contortus. A simple analysis revealed strong relationships between single blood parameters and WECs with correlation coefficients -0.54 to -0.60. We then used more complex multi-variate methods based on supervised classifier models (including Bayesian Network) as well as regression models (Lasso and Elastic Net) to study the relationships between WECs and blood parameters, and derived algorithms describing the relationships. The ability of these algorithms to classify sheep GIN resistance status was tested using the WEC and blood parameters collected from a different group of 418 sheep that had acquired natural infections of H. contortus from pasture. We identified the most resistant and most susceptible animals (10% percentiles) of this group based on WECs, and then compared the identities of these animals to the identities of animals that were predicted to be most resistant and most susceptible by our algorithms. The models showed varying abilities to predict susceptible and resistant sheep, with up to 65% of the most susceptible animals and 30% of the most resistant animals identified by the Elastic Net model algorithms. The prediction algorithms derived from female sheep data performed better than those for male sheep in some cases, with the predicted animals accounting for up to 50-60% of the actual resistant and susceptible female animals. Heritability values were calculated for blood parameters and the aggregate trait descriptions defined by the novel prediction algorithms. The aggregate trait descriptions were moderately heritable and may therefore be suitable for use in genetic selection strategies. The present study indicates that multivariate models based on blood parameter data showed some ability to predict the resistance status of sheep to infection with H. contortus.


Assuntos
Resistência à Doença , Modelos Biológicos , Infecções por Nematoides/veterinária , Doenças dos Ovinos/sangue , Doenças dos Ovinos/parasitologia , Algoritmos , Animais , Análise Química do Sangue , Cruzamento , Feminino , Masculino , Nematoides , Infecções por Nematoides/sangue , Infecções por Nematoides/imunologia , Ovinos , Doenças dos Ovinos/imunologia
4.
Vet Parasitol ; 270: 49-55, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31213241

RESUMO

Variation in the timing of development of immunity to gastro-intestinal nematode parasites was assessed in resistant and resilient Romney selection lines exposed to mixed natural infection. From weaning, at mean 92 days-of-age, animals (n = 53) were sampled for faecal egg count (FEC) expressed as eggs per gram of faeces (epg), saliva for immunoglobulin (IgG and IgA) determination and fasted live weight (LW) every 10 days until 351 days-of-age. Overall, mean back-transformed FEC were consistently low for resistant animals (<200 epg) whereas resilient counterparts' FEC increased with time to reach a peak of 1400 epg at day 230 for females and 1800 epg for males at day 280 before declining to less than 500 epg by day 300, respectively (P < 0.001). Resistant lambs reached a threshold for Trichostrongylus colubriformis L3-specific IgG which was indicative of the presence of immunity earlier at 220.6 ± 8.8 days-of-age compared with resilient-line animals which reach this threshold 40 days later at 263.4 ± 6.9 days-of-age (P < 0.001). In addition, resistant females reached sexual maturity earlier compared with their resilient counterparts viz. 263.5 ± 3.7 c.f. 274.4 ± 3.4 days-of-age, respectively, (P = 0.048). Mean fasted live weight (LW) showed a selection line by time interaction (P < 0.001) which reflected greater LW in the early phase of the study in resilient males but increasing for all groups until day 280 before declining and being similar for all groups from day 330. In summary, differences appear to exist in the timing of immune development between these Romney lines, with resistant animals developing immunity earlier and these resistant-line animals also appear to be more physiologically mature at the same chronological age than resilient animals. These observations have implications on the timing of identification and selection of resistant animals.


Assuntos
Cruzamento , Resistência à Doença/imunologia , Doenças dos Ovinos/imunologia , Tricostrongilose/veterinária , Animais , Feminino , Masculino , Seleção Genética , Maturidade Sexual , Ovinos , Tricostrongilose/imunologia
5.
Parasitol Res ; 118(8): 2383-2388, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203449

RESUMO

In this study, we evaluated in two trials a protocol designed to protect hair sheep using Barbervax®, a vaccine containing Haemonchus contortus gut membrane glycoprotein antigens. Results indicated that naturally infected vaccinated sheep had significant egg count reductions (90.2 ± 4.03%) compared with controls, although blood parameters remained relatively unchanged probably because the level of challenge was low. Vaccination prevented the periparturient rise in egg shedding of ewes, as well as egg shedding in lambs (37.1%). In the second trial, sheep which were experimentally exposed to higher artificial challenge also showed an efficient response to the vaccine as confirmed by high antibody levels and reduced egg counts and worm burdens (87 ± 5.4% and 79%) respectively. Thus, we believe that the vaccine should be integrated with other management practices for meat hair sheep as it has the advantages of adequate efficacy, reducing anthelmintic utilization and avoiding milk and environmental contamination with chemical residues.


Assuntos
Hemoncose/veterinária , Haemonchus/imunologia , Doenças dos Ovinos/prevenção & controle , Vacinação/métodos , Vacinas/administração & dosagem , Animais , Anticorpos Anti-Helmínticos/imunologia , Feminino , Hemoncose/imunologia , Hemoncose/parasitologia , Hemoncose/prevenção & controle , Haemonchus/genética , Contagem de Ovos de Parasitas/veterinária , Ovinos , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/parasitologia , Vacinas/imunologia
6.
Vet Parasitol ; 269: 16-20, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31079822

RESUMO

Teladorsagia circumcincta is the dominant nematode of sheep in cool, temperate climates. Faecal nematode egg counts (FEC) are widely used to identify the intensity of infection and as a measure of host resistance to nematodes. However due to density-dependent effects on worm fecundity the relationship between FEC and worm burden is not linear. In addition collecting FEC data is challenging on a practical level and there is a need for more reliable markers of resistance. There are two major known mechanisms of immunity to T. circumcincta: IgE against third stage larvae (L3) and IgA against fourth stage larvae (L4), which inhibits parasite growth. In this study salivary IgA responses were measured in over 5000 animals against L3 antigen by Enzyme Linked Immunosorbent Assay (ELISA). Antigen-specific IgA levels were negatively correlated with FEC (r=-0.26, SE = 0.02) and were heritable (h2 = 0.16, SE = 0.04) indicating that they can be used to identify resistant animals suitable for inclusion in selective breeding programs. Antigen-specific IgA responses were not negatively correlated with muscle depth. Our analyses indicate that selection for T. circumcincta L3 antigen-specific IgA is possible without impacting on the production traits for the Lleyn breed.


Assuntos
Anticorpos Anti-Helmínticos/imunologia , Imunoglobulina A/imunologia , Ostertagia/imunologia , Doenças dos Ovinos/imunologia , Animais , Biomarcadores/análise , Cruzamento , Ensaio de Imunoadsorção Enzimática/veterinária , Fezes/parasitologia , Feminino , Contagem de Ovos de Parasitas/veterinária , Fenótipo , Saliva/imunologia , Ovinos , Doenças dos Ovinos/parasitologia
7.
Parasit Vectors ; 12(1): 182, 2019 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31023355

RESUMO

BACKGROUND: Pattern recognition receptors (PRRs) can recognize pathogen-associated molecular patterns and activate downstream signalling pathways, resulting in modulation of host immunity against pathogens. Here, we investigated whether PRR-mediated recognition is involved in host immune responses to the blood-feeding nematode Haemonchus contortus. METHODS: During blood-feeding, H. contortus secretes immune-modulating antigens into host blood. Therefore, we stimulated sheep peripheral blood mononuclear cells (PBMCs) with H. contortus soluble extract (HcAg) and performed transcriptional profiling. RESULTS: HcAg upregulated two genetically linked CLRs (CLEC2L and KLRG2), two NLRs attenuating inflammation (NLRP12 and NLRC3) and one G protein-coupled receptor with potent anti-inflammatory effects (HCAR2). Furthermore, several Th2-related transcription factors (ATF3, IRF4, BCL3 and NFATC) were also upregulated, which may confer anti-inflammatory type 2 immune responses to HcAg. CONCLUSIONS: Together, our preliminary studies provide new insights into how the host innate immune system controls type 2 immunity to H. contortus. Further work will be needed to identify H. contortus products recognized by the host innate immune system and determine the Th2 polarization ability of these putative PRR ligands.


Assuntos
Hemoncose/veterinária , Haemonchus/química , Proteínas de Helminto/farmacologia , Imunidade Inata , Leucócitos Mononucleares/imunologia , Extratos de Tecidos/farmacologia , Animais , Antígenos de Helmintos/imunologia , Perfilação da Expressão Gênica , Hemoncose/sangue , Proteínas de Helminto/imunologia , Interações Hospedeiro-Patógeno , Leucócitos Mononucleares/parasitologia , Proteínas NLR/genética , Receptores de Reconhecimento de Padrão/genética , Receptores de Reconhecimento de Padrão/imunologia , Ovinos , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/parasitologia , Fatores de Transcrição/genética
9.
Onderstepoort J Vet Res ; 86(1): e1-e6, 2019 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-30843407

RESUMO

Malignant ovine theileriosis is caused by Theileria lestoquardi, which is highly pathogenic in sheep. Theileriosis involves different organs in ruminants. Little is known about the role of proinflammatory cytokines in the pathogenesis of T. lestoquardi infection. The aim of this study was to measure concentration changes of proinflammatory cytokines and immunoglobulin G (IgG) during an ovine experimental theileriosis and correlate it with clinical and haematological parameters. During an experimental study, seven healthy Baluchi sheep (four females and three males) about 6-8 months old were infected with T. lestoquardi by feeding of infected unfed ticks on the sheep's ears. The infected sheep were clinically examined during the study and blood samples were collected on days 0, 2, 5, 7, 10, 12, 14, 17 and 21. The haematological parameters were analysed by an automatic veterinary haematology cell counter and the inflammatory cytokines interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α), interferon-γ (IFN-γ) and IgG were measured by enzyme-linked immunosorbent assay. All infected sheep had temperatures above 40 °C on days 3-4 post infection (PI). The maximum temperature was noted on day 7, and it remained high until day 21. The parasitaemia of T. lestoquardi infection increased from 0.01% (day 7 PI) to 3.3% (day 21 PI). The mean white blood cell (WBC), red blood cell (RBC), lymphocyte, neutrophil and platelet values slightly increased on day 2 PI and decreased by day 17 and day 21 PI. The percentage parasitaemia and fever had a negative correlation with the numbers of WBCs, RBCs, lymphocytes, neutrophils and platelets. The serum concentration of IL-6, TNF-α and IFN-γ cytokines increased and peaked on day 12 and thereafter decreased to levels lower than 0. Out of all tested cytokines, the concentration of IL-6 was significantly higher, as early as day 2 PI. No significant changes were observed for the IgG levels during the course of disease. A significant and strong correlation was observed between IL-6, TNF-α and IFN-γ values and a moderate correlation between IL-6 and the numbers of lymphocytes in the present study. A strong correlation was determined between the percentage parasitaemia and haematological parameters in T. lestoquardi-infected sheep. In addition, preliminary results indicate that the measurement of the serum concentrations of IL-6 in combination with haematological parameters could be considered a good marker to estimate the pathogenicity of T. lestoquardi strain.


Assuntos
Doenças dos Ovinos/sangue , Doenças dos Ovinos/imunologia , Theileriose/sangue , Theileriose/imunologia , Animais , Citocinas , Feminino , Imunoglobulina G , Masculino , Ovinos , Doenças dos Ovinos/parasitologia , Carneiro Doméstico , Theileria , Theileriose/parasitologia
10.
Animal ; 13(9): 1788-1796, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30700340

RESUMO

Breeding for resistance against nematodes has become the need of the hour due to emergence of anthelmintic resistant strains of major pathogenic nematodes of economic importance and rising demand for chemical residue free food by consumers. ICAR-Central Sheep and Wool Research Institute Avikanagar (Rajasthan) has developed Haemonchus contortus resistant lines of sheep in Avikalin and Malpura breeds by harvesting benefits of over-dispersion in fecal egg counts (FEC) through executing a breeding program since year 2004. Aim of the present study was to assess the genetic parameters for nematode resistance in these lines and also to develop suitable criteria for selection targeting resistance as well as growth improvement in these two lines. The data on 1240 Avikalin and 2172 Malpura sheep generated over 13 years (2004-16) for FEC along with deep pedigree and growth records for live weight at 6 (6WT) and 12 month were used for study. Data were analyzed using Average Information Restricted Maximum Likelihood (AIREML) approach. Results revealed moderate heritability (h2) for pre-drench log transformed fecal egg count (LFEC) in Avikalin (0.21±0.06) and Malpura (0.18±0.04) sheep. The post-drench h2 for LFEC was low in Avikalin (0.04±0.03) and Malpura (0.11±0.03) sheep. Effective selection program can be carried out for further improving the resistance against H. contortus in both the breeds using pre-drench LFEC estimates. The genetic correlation between the pre-drench LFEC and growth traits was not in the desired direction. Existence of substantial genotype × environment (G×E) interaction was seen in Malpura sheep, where major shift in ranks of sheep based on pre-drench LFEC as that of post-drench LFEC was observed owing to genetic correlation of 0.65±0.15. The G×E was absent in Avikalin sheep. Unreliable genetic correlation between growth and LFEC does not warrant a multi trait selection index development and its utilization in breeding program. The independent selection for LFEC followed by corrected 6WT can precisely help in achieving the goal of improving growth in nematode resistant sheep.


Assuntos
Anti-Helmínticos/farmacologia , Resistência à Doença/genética , Hemoncose/veterinária , Nematoides/crescimento & desenvolvimento , Doenças dos Ovinos/imunologia , Animais , Cruzamento , Fezes/parasitologia , Feminino , Hemoncose/imunologia , Hemoncose/parasitologia , Haemonchus/crescimento & desenvolvimento , Masculino , Nematoides/efeitos dos fármacos , Contagem de Ovos de Parasitas/veterinária , Linhagem , Fenótipo , Ovinos , Doenças dos Ovinos/parasitologia
11.
Transbound Emerg Dis ; 66(1): 505-516, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30375177

RESUMO

Brucellosis is a worldwide zoonosis causing important economic loss and a public health problem. Small ruminants are the preferred hosts of Brucella melitensis and thus the main source of human infections. Effective control of sheep and goat brucellosis has been achieved in several countries through vaccination with the live-attenuated B. melitensis Rev1 vaccine. However, Rev1 induces a long-lasting serological response that hinders the differentiation between infected and vaccinated animals. A Rev1::gfp strain expressing constitutively the Green Fluorescent Protein (GFP) was built by stable insertion of a mini-Tn7-gfp in the glmS-recG non-codifying chromosomal region. An associated indirect ELISA-GFP was developed to identify anti-GFP antibodies in vaccinated animals. The resulting Rev1::gfp kept the biological properties of the Rev1 reference strain, including residual virulence and efficacy in mice, and was readily distinguished from Rev1 and other Brucella field strains by direct visualization under ultraviolet illumination, fluorescence microscopy and a multiplex PCR-GFP. The Rev1::gfp strain did not elicit anti-GFP antibodies itself in lambs but when applied in combination with recombinant GFP induced an intense and long-lasting (>9 months) anti-GFP serological response readily detectable by the ELISA-GFP. Overall, our results confirm that Rev1 GFP-tagging can be a suitable alternative for identifying vaccinated sheep in infected contexts.


Assuntos
Vacina contra Brucelose/administração & dosagem , Brucella melitensis/imunologia , Brucelose/veterinária , Proteínas de Fluorescência Verde/imunologia , Imunoglobulina G/sangue , Doenças dos Ovinos/prevenção & controle , Vacinação/veterinária , Animais , Vacina contra Brucelose/imunologia , Brucelose/imunologia , Brucelose/prevenção & controle , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Substâncias Luminescentes , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Microscopia de Fluorescência/veterinária , Ovinos , Doenças dos Ovinos/diagnóstico , Doenças dos Ovinos/imunologia , Vacinas Atenuadas/imunologia
12.
Transbound Emerg Dis ; 66(1): 537-545, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30394662

RESUMO

Competitive-ELISA (c-ELISA) is the most widely used serological test for the detection of Bluetongue virus (BTV) viral protein 7 (VP7) antibodies (Ab). However, these BTV c-ELISAs cannot to distinguish between IgG and IgM. IgM Ab are generated shortly after the primary immune response against an infectious agent, indicating a recent infection or exposure to antigens, such as after vaccination. Because the BTV genome or anti-VP7 Ab can be detected in ruminant blood months after infection, BTV diagnostic tools cannot discriminate between recent and old infections. In this study, we evaluated an IgM-capture ELISA prototype to detect ruminant anti-BTV VP7 IgM on 1,650 serum samples from cattle, sheep, or goats. Animals were BTV-naive, infected, or/and vaccinated with BTV-1, -2, -4, -8, -9, -16, or -27, and we also included 30 sera from cattle infected with the Epizootic haemorrhagic disease virus (EHDV) serotype 6. Results demonstrated that this ELISA kit is specific and can detect the presence of IgM with satisfactory diagnostic specificity and sensitivity from 1 to 5 weeks after BTV infection in domestic ruminants (for goats and cattle; for sheep, at least up to 24 days). The peak of anti-VP7 IgM was reached when the level of infectious viruses and BTV RNA in blood were the highest. The possibility of detecting BTV-RNA in IgM-positive sera allows the amplification and sequencing of the partial RNA segment 2 (encoding the serotype specific to VP2) to determine the causative BTV serotype/strain. Therefore, BTV IgM ELISA can detect the introduction of BTV (or EHDV) in an area with BTV-seropositive domestic animals regardless of their serological BTV status. This approach may also be of particular interest for retrospective epidemiological studies on frozen serum samples.


Assuntos
Animais Domésticos/virologia , Anticorpos Antivirais/sangue , Vírus Bluetongue/imunologia , Bluetongue/diagnóstico , Ensaio de Imunoadsorção Enzimática/veterinária , Imunoglobulina M/sangue , Proteínas do Core Viral/imunologia , Animais , Bluetongue/imunologia , Bluetongue/virologia , Bovinos , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/virologia , Diagnóstico Precoce , Doenças das Cabras/diagnóstico , Doenças das Cabras/imunologia , Doenças das Cabras/virologia , Cabras , Estudos Retrospectivos , Ruminantes , Sorogrupo , Testes Sorológicos/métodos , Ovinos , Doenças dos Ovinos/diagnóstico , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/virologia
13.
J Vet Diagn Invest ; 31(1): 78-82, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30541409

RESUMO

Seven colostrum-deprived, 3-4-wk-old Rambouillet-Hampshire lambs were inoculated via the mucous membranes with deer adenovirus (DAdV) and monitored for clinical signs for 21 d post-inoculation at which time animals were euthanized and postmortem examinations were performed. Pre-inoculation and post-inoculation serum samples were tested for antibodies to DAdV, ovine adenovirus 7, bovine adenovirus 7, and goat adenovirus 1. Evidence for DAdV infection was determined by virus isolation, PCR tests, and histopathology with immunohistochemistry tests for DAdV. No clinical signs or lesions consistent with adenoviral hemorrhagic disease (AHD) in deer were seen in the lambs, and the lambs did not seroconvert to DAdV. DAdV was not detected by PCR, virus isolation, or immunohistochemistry in any of the samples tested from the lambs. A positive control deer similarly inoculated with DAdV developed fatal AHD 1 wk post-inoculation. Our colostrum-deprived lambs did not become infected when inoculated with DAdV.


Assuntos
Infecções por Adenoviridae/veterinária , Atadenovirus/isolamento & purificação , Colostro/imunologia , Doenças dos Ovinos/virologia , Infecções por Adenoviridae/imunologia , Animais , Animais Domésticos , Animais Recém-Nascidos , Animais Lactentes , Atadenovirus/imunologia , Feminino , Imuno-Histoquímica/veterinária , Reação em Cadeia da Polimerase/veterinária , Gravidez , Ovinos , Doenças dos Ovinos/imunologia
14.
Vet Immunol Immunopathol ; 207: 1-9, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30593344

RESUMO

Since CD8+ T cells play an important role in resistance to infection with heartwater, effective vaccines against this disease will likely require identification of antigens that contain CD8+ T cell epitopes responsible for cytotoxic T lymphocyte (CTL) responses. With the use of the fluorescent antigen-transfected target cell (FATT)-CTL assay, IFN-γ ELISPOT and flow cytometry, peptides that induce CTL, proliferation of CD8 + T cells and IFN-γ production were identified as possible target antigens for vaccine development. Of particular relevance was the finding that different peptides from different antigens were able to elicit varied cytotoxic activities by immune peripheral blood mononuclear cells (PBMC) from heartwater immune tick-infected sheep. Several peptides derived from Erum0660, Erum2330, Erum2540, Erum2580 and Erum5000 induced CTL in immune sheep PBMC. Peptide Erum2540-6 was the only peptide that induced significant CTL, CD8+CD45RO+ and CD8+IFN-γ+ by PBMC from all three sheep, and Erum2540 and p2540-20 induced the highest % CTL response in all three outbred sheep. These results suggest that these epitopes may be of major importance in heartwater recombinant vaccine development.


Assuntos
Antígenos de Bactérias/imunologia , Ehrlichia ruminantium/imunologia , Peptídeos/imunologia , Linfócitos T Citotóxicos/imunologia , Animais , Vacinas Bacterianas/imunologia , Epitopos/imunologia , Feminino , Imunofluorescência/veterinária , Hidropericárdio/imunologia , Hidropericárdio/microbiologia , Hidropericárdio/prevenção & controle , Técnicas In Vitro , Ativação Linfocitária/imunologia , Masculino , Reação em Cadeia da Polimerase/veterinária , Ovinos/imunologia , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/microbiologia , Doenças dos Ovinos/prevenção & controle
15.
Vet Immunol Immunopathol ; 206: 1-8, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30502907

RESUMO

The immunomodulatory functions mediated by melatonin support its use as vaccine adjuvant. Previously, we have demonstrated that melatonin enhances antibody responses in sheep vaccinated against Dichelobacter nodosus. Here, we analyze the effect of melatonin on T and B lymphocyte subsets in peripheral blood of sheep vaccinated against D. nodosus. We also compare the use of melatonin in implants and in injections. Melatonin administration either as implants or by injection produced higher antibody titers against A1 and C serotypes compared to those animals that received only the vaccine. These results support the use of melatonin as an adjuvant in vaccination against D. nodosus. Firstly, melatonin induces higher antibody titer than the vaccine alone, secondly, melatonin increase IgG+ B lymphocytes and CD4+ T lymphocytes in vaccinated sheep. These results suggest that melatonin enhances T CD4 cell activation and subsequently secondary humoral immune responses. Further studies are required to determine the mechanism underlining the immunomodulatory role of melatonin in the context of vaccination.


Assuntos
Linfócitos B/imunologia , Vacinas Bacterianas/imunologia , Linfócitos T CD4-Positivos/imunologia , Dichelobacter nodosus/imunologia , Infecções por Bactérias Gram-Negativas/veterinária , Melatonina/uso terapêutico , Doenças dos Ovinos/imunologia , Adjuvantes Imunológicos/uso terapêutico , Administração Cutânea , Animais , Anticorpos Antibacterianos/sangue , Vacinas Bacterianas/administração & dosagem , Implantes de Medicamento , Feminino , Citometria de Fluxo/veterinária , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/prevenção & controle , Imunogenicidade da Vacina/efeitos dos fármacos , Imunoglobulina G/sangue , Melatonina/administração & dosagem , Distribuição Aleatória , Ovinos , Doenças dos Ovinos/prevenção & controle
16.
Vet Parasitol ; 264: 52-57, 2018 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-30503092

RESUMO

Haemonchus contortus is an economic problem in sheep farms worldwide, mainly in the tropics and subtropics. A vaccine against haemonchosis, called Barbervax®, was evaluated in ewes under two nutritional status, naturally infected with gastrointestinal nematodes. Ewes were divided into four groups: Supplemented Diet - Vaccine; Supplemented Diet - No vaccine; Basal Diet - Vaccine and Basal Diet - No vaccine. Their lambs were divided in Vaccinated and No vaccine. Ewes were immunised six times starting about 1 month of pregnancy with the first three doses at 3 week intervals and the last three shots at 4 week intervals. Supplemented ewes had higher body weight, body score and packed cell volume compared with those fed a basal diet. Both groups of vaccinated ewes showed a similar response in circulating anti-vaccine antibodies but the vaccine had no discernible effect on either body weight, body score and packed cell volume. There was a marked group difference in the number of ewes that received precautionary treatments with anthelmintic. All 14 Basal Diet - No vaccine ewes required treatment. In contrast only 7 ewes, in the Supplemented Diet - Vaccine group required anthelmintic treatment. In the Basal Diet - Vaccine and in the Supplemented Diet - No Vaccine groups, 12 and 13 ewes needed anthelmintic treatment, respectively. Vaccinated lambs showed much higher antibody titres resulting in 80% less Haemonchus spp. egg counts comparing with no vaccine lambs. Taken together these results clearly suggest that in pregnant and lactating ewes a combined protective effect between vaccination and improved nutrition resulted in fewer precautionary anthelmintic treatments. Thus, it was possible to achieve a more sustainable level of control of the haemonchosis, less dependent on anthelmintic drugs.


Assuntos
Suplementos Nutricionais , Hemoncose/veterinária , Nutrientes/imunologia , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/prevenção & controle , Vacinas/imunologia , Animais , Anticorpos Anti-Helmínticos/sangue , Feminino , Hemoncose/imunologia , Hemoncose/prevenção & controle , Haemonchus/imunologia , Nutrientes/administração & dosagem , Gravidez , Ovinos , Clima Tropical , Vacinas/administração & dosagem , Ganho de Peso/imunologia
17.
Vet Microbiol ; 227: 97-102, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30473359

RESUMO

Batai virus (BATV), a mosquito-transmitted Orthobunyavirus, was first detected in Southwest Germany in anopheline and culicine mosquitoes in 2009. However, little is known about the exposure to BATV infections for farm animals and humans in Germany as almost no systematic surveillance or infection studies have been carried out to date. This may explain why clinical symptoms in animals or humans have not been reported so far. Therefore and since BATV has meanwhile been detected repeatedly in different mosquito species in several regions of Germany, we performed a surveillance study by assaying more than 1300 blood samples from ruminants (goats, bovines, sheep) from six different federal states covering the years 2013 to 2016. Samples were investigated by BATV-specific real-time polymerase chain reaction as well as by virus neutralisation test. BATV-specific RNA was not detected, whereas BATV-specific antibodies were found in livestock from various geographic regions. We have determined the seroprevalence of 38.8% for goats, 44.7% for sheep and 36.4% for bovines in Saxony-Anhalt. The seroprevalence of goats from Brandenburg was 38.6% and of goats from Saxony 28.4%. These results confirm the levels of seroprevalence to BATV, suggesting endemic circulation, in different regions and indicate that ruminants are potential hosts of BATV in East Germany. Furthermore, the role of BATV as segment donor in disease emergence events should not be overlooked.


Assuntos
Vírus Bunyamwera/genética , Vírus Bunyamwera/imunologia , Infecções por Bunyaviridae/veterinária , Monitoramento Epidemiológico/veterinária , Ruminantes/virologia , Animais , Vírus Bunyamwera/isolamento & purificação , Infecções por Bunyaviridae/epidemiologia , Infecções por Bunyaviridae/imunologia , Infecções por Bunyaviridae/transmissão , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/transmissão , Doenças dos Bovinos/virologia , Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/transmissão , Doenças Transmissíveis Emergentes/virologia , Culicidae/virologia , Alemanha/epidemiologia , Doenças das Cabras/epidemiologia , Doenças das Cabras/imunologia , Doenças das Cabras/transmissão , Doenças das Cabras/virologia , Cabras , Mosquitos Vetores/virologia , Filogenia , RNA Viral/sangue , Estudos Soroepidemiológicos , Ovinos , Doenças dos Ovinos/epidemiologia , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/transmissão , Doenças dos Ovinos/virologia
18.
Am Nat ; 192(6): 745-760, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30444657

RESUMO

An effective immune response is expected to confer fitness benefits through improved resistance to parasites but also incur energetic costs that negatively impact fitness-related traits, such as reproduction. The fitness costs and benefits of an immune response are likely to depend on host age, sex, and levels of parasite exposure. Few studies have examined the full extent to which patterns of natural selection on immune phenotypes vary across demographic groups and environments in the wild. Here, we assessed natural selection on plasma levels of three functionally distinct isotypes (IgA, IgE, and IgG) of antibodies against a prevalent nematode parasite measured in a wild Soay sheep population over 26 years. We found little support for environment-dependent selection or reproductive costs. However, antibody levels were negatively associated with parasite egg counts and positively associated with subsequent survival, albeit in a highly age- and isotype-dependent manner. Raised levels of antiparasite IgA best predicted reduced egg counts, but this did not predict survival in lambs. In adults increased antiparasite IgG predicted reduced egg counts, and in adult females IgG levels also positively predicted overwinter survival. Our results highlight the potential importance of age- and sex-dependent selection on immune phenotypes in nature and show that patterns of selection can vary even among functionally related immune markers.


Assuntos
Anticorpos Anti-Helmínticos/genética , Seleção Genética , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/parasitologia , Carneiro Doméstico/genética , Animais , Fezes/parasitologia , Feminino , Isotipos de Imunoglobulinas/sangue , Masculino , Contagem de Ovos de Parasitas , Escócia , Ovinos , Análise de Sobrevida , Trichostrongyloidea/imunologia , Tricostrongiloidíase/imunologia , Tricostrongiloidíase/veterinária
19.
Front Immunol ; 9: 2592, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30483259

RESUMO

Oral vaccination with edible vaccines is one of the most promising approaches in modern vaccinology. Edible vaccines are an alternative to conventional vaccines, which are typically delivered by injection. Here, freeze-dried transgenic lettuce expressing the cysteine proteinase of the trematode Fasciola hepatica (CPFhW) was used to orally vaccinate cattle and sheep against fasciolosis, which is the most important trematode disease due to the parasite's global distribution, wide spectrum of host species and significant economic losses of farmers. In the study, goals such as reducing the intensity of infection, liver damage and F. hepatica fecundity were achieved. Moreover, we demonstrated that the host sex influenced the outcome of infection following vaccination, with female calves and male lambs showing better protection than their counterparts. Since differences occurred following vaccination and infection, different immunization strategies should be considered for different sexes and host species when developing new control methods. The results of the present study highlight the potential of oral vaccination with plant-made and plant-delivered vaccines for F. hepatica infection control.


Assuntos
Cisteína Proteases/imunologia , Fasciola hepatica/imunologia , Alface/imunologia , Gado/imunologia , Vacinas de Plantas Comestíveis/imunologia , Animais , Anticorpos Anti-Helmínticos/imunologia , Antígenos de Helmintos/imunologia , Bovinos , Doenças dos Bovinos/imunologia , Fasciolíase/imunologia , Fasciolíase/veterinária , Feminino , Fertilidade/imunologia , Masculino , Ovinos/imunologia , Doenças dos Ovinos/imunologia , Vacinação/veterinária
20.
Vet Microbiol ; 225: 31-33, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30322529

RESUMO

Chlamydia abortus is responsible for enzootic abortion (known as ovine enzootic abortion (OEA) and enzootic abortion of ewes (EAE)) in both sheep and goats and has major economic implications for the farming industry worldwide. A virulence-attenuated mutant strain of C. abortus (strain 1B) is currently commercially available as a live attenuated vaccine for immunization of sheep and goats in several European countries. Following an abortion storm in a French flock of 200 ewes that occurred two years after vaccination of 36 replacement ewes with the commercial 1B vaccine strain, the vaginal swabs of 3 vaccinated and 7 unvaccinated aborted ewes and 12 of the 13 dead fetuses were found to be positive for C. abortus by real-time PCR. Genotyping of the samples, using vaccine-specific SNP markers, identified all as positive for the vaccine-type strain. The recent vaccination of this flock with the attenuated commercial vaccine strain, the large number of abortion cases observed in ewes irrespective of vaccination status, the high C. abortus load detected in vaginal swabs or abortion tissues and the identification of specific vaccine-type markers in these samples strongly suggest that the 1B strain has been transmitted from vaccinated to naïve animals, thus mimicking a natural wild-type infection.


Assuntos
Feto Abortado/microbiologia , Aborto Animal/epidemiologia , Vacinas Bacterianas/efeitos adversos , Infecções por Chlamydophila/veterinária , Vacinação/efeitos adversos , Aborto Animal/microbiologia , Aborto Animal/prevenção & controle , Animais , Vacinas Bacterianas/administração & dosagem , Chlamydophila/genética , Infecções por Chlamydophila/microbiologia , Infecções por Chlamydophila/mortalidade , Infecções por Chlamydophila/prevenção & controle , Feminino , França/epidemiologia , Mutação , Reação em Cadeia da Polimerase , Gravidez , Reação em Cadeia da Polimerase em Tempo Real , Ovinos/imunologia , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/prevenção & controle , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/efeitos adversos , Vacinas Atenuadas/imunologia , Vagina/microbiologia , Sequenciamento Completo do Genoma
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