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1.
J Parasitol ; 106(3): 392-394, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32556162

RESUMO

The objective of the study was to identify the seroprevalence of anti-Toxoplasma gondii antibodies in sheep herds from 3 municipalities from Jalisco, Mexico, as well as estimate the association between seroprevalence and certain factors presents in the farms. In total, 12 sheep farms that maintain only hair breeds were included in the work. From these farms, 336 blood samples were collected, corresponding 324 to ewes and 12 rams. Serum samples were subjected to ELISA test, and the association between the frequency of antibodies and some potential risk factors was estimated. The overall seroprevalence to anti-T. gondii antibodies in the population studied was 17.8% (60/336; 95% confidence interval [C.I.] 14-22), all farms had positive animals, and the seroprevalence of antibodies ranged between 7 to 32%. Seroprevalence in specific municipalities was 18.7% in Lagos de Moreno, 17.8% in Encarnación de Díaz, and 16.9% in San Juan de los Lagos. Seroprevalence in ewes was 17.5% (57/324; 95% C.I. 13-22), and seroprevalence in rams was 25% (3/12; 95% C.I. 6-57), while among breeds it was 17.8% in Pelibuey (20/112; 95% C.I. 11-26), 16.6% in Kathadin (14/84; 95% C.I. 9-26), 15.4% in Blackbelly (13/84; 95% C.I. 8-25), and 23.2% in Dorper (13/56; 95% C.I. 13-36); no differences were observed among breeds (p < 0.05). The presence of cats on the farms was associated with seroprevalence (odds ratio [OR] 2.8; 95% C.I. 1.8-7.3, p < 0.001), as was the absence of a rodent-control program (OR 1.5; 95% C.I. 0.8-3.2, p < 0.05). No other factors were identified as associated with seroprevalence.


Assuntos
Anticorpos Antiprotozoários/sangue , Doenças dos Ovinos/parasitologia , Toxoplasma/imunologia , Toxoplasmose Animal/epidemiologia , Animais , Gatos , Feminino , Masculino , México/epidemiologia , Controle de Pragas/estatística & dados numéricos , Ratos , Estudos Soroepidemiológicos , Ovinos , Doenças dos Ovinos/epidemiologia , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/transmissão , Inquéritos e Questionários , Toxoplasmose Animal/imunologia , Toxoplasmose Animal/parasitologia , Toxoplasmose Animal/transmissão
2.
Vet Clin North Am Food Anim Pract ; 36(1): 159-171, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32029181

RESUMO

This article summarizes the state of the art in vaccine research against parasitic helminths in sheep and cattle. Optimization of antigen production (eg, recombinant expression) and antigen delivery, followed by extensive field testing, is still required for further development of vaccines. Helminth vaccines should sufficiently reduce parasite transmission to protect vaccinated animals against parasite-induced disorders and production loss. Vaccine efficacy requirements depend on the parasite's epidemiology and farm management, both of which vary in different geographic regions and are influenced by climate. Vaccination is likely to be part of integrated worm control, together with other worm control measures.


Assuntos
Doenças dos Bovinos/prevenção & controle , Doenças das Cabras/prevenção & controle , Helmintos/imunologia , Doenças dos Ovinos/prevenção & controle , Vacinas/administração & dosagem , Animais , Bovinos , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/parasitologia , Doenças das Cabras/imunologia , Doenças das Cabras/parasitologia , Cabras , Ovinos , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/parasitologia , Vacinação/veterinária , Vacinas/imunologia
3.
J Immunoassay Immunochem ; 41(2): 152-157, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32028862

RESUMO

Q fever, caused by Coxiella burnetii, is an important zoonosis worldwide. Q fever is documented in many parts of the world; however, information on the disease in Ghana is scanty. This study was therefore conducted to provide evidence of exposure of sheep and goats slaughtered at the Kumasi Abattoir to Coxiella burnetii. A total of 350 serum samples collected from 175 sheep and 175 goats were analyzed for the presence of C. burnetii antibodies using a commercial ELISA kit (ID Vet). Results of the study established a seroprevalence of 28.57% in goats, 16.57% in sheep and an overall seroprevalence of 22.29% in sheep and goats; 20.57% for male sheep, 23.86% for female sheep, 26.44% for male goats and 30.68% for female goats. Results showed that goats are more at risk to the infection than sheep however sex is not a risk factor. This study confirms the existence of Q fever in sheep and goats in Ghana hence, the disease should be considered as a public health risk to workers at the abattoir and other stakeholders in the sheep and goat production chain.


Assuntos
Infecções Bacterianas/imunologia , Coxiella burnetii/imunologia , Doenças das Cabras/imunologia , Doenças dos Ovinos/imunologia , Animais , Infecções Bacterianas/sangue , Infecções Bacterianas/microbiologia , Estudos Transversais , Ensaio de Imunoadsorção Enzimática , Feminino , Gana , Doenças das Cabras/sangue , Doenças das Cabras/microbiologia , Cabras , Masculino , Fatores de Risco , Ovinos , Doenças dos Ovinos/sangue , Doenças dos Ovinos/microbiologia
4.
Benef Microbes ; 11(2): 175-181, 2020 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-31990221

RESUMO

Studies aiming at the development and evaluation of alternative methods to minimise losses caused by the gastrointestinal nematode Haemonchus contortus are extremely important. Such research is essential, given the high morbidity rates among sheep and the significant mortality rates of lambs, allied to the low efficacy of commercial products for the control of this parasite. The purpose of this study was to evaluate the effect of the Saccharomyces cerevisiae (YT001 - YEASTECH) on the control of H. contortus and its modulation of the immune response in experimentally infected sheep. Eighteen sheep were divided into two groups. Group 1, the control group, comprised animals infected with H. contortus and supplemented with distilled water, while Group 2, the treated group, consisted of animals infected and supplemented with S. cerevisiae (400 million cfu/day of suspension for 49 days). The following parasitological parameters were evaluated: number of eggs per gram of faeces, number of infective larvae (L3) recovered per faecal culture, and parasitic load of the abomasum. The following immunological parameters were quantified: immunoglobulin (Ig)A in the mucous secretions and serum IgG; cytokines interleukin (IL)-4, IL-5 and IL-10; number of eosinophils in the abomasal mucosa and groups of cells positive for the markers: MHCII, CD4+CD25+, CD5+CD8+, WC4, CD5+CD4+, CD8+CD11b+ and CD5+WC1 by whole blood flow cytometry. The results revealed a significant decrease (P<0.05) in the number of larvae and significantly higher serum IgG levels (P<0.05) in the group supplemented with S. cerevisiae. The supplemented animals showed significantly larger numbers of eosinophils (P<0.05), as well as more cells positive for MHCII, CD4+CD25+, CD5+CD8+ than the control animals. This study confirmed the beneficial action of S. cerevisiae on the host immune response to H. contortus, as evidenced mainly by the smaller number of L3 recovered from the faeces of sheep supplemented with S. cerevisiae.


Assuntos
Suplementos Nutricionais/microbiologia , Hemoncose/veterinária , Probióticos/administração & dosagem , Saccharomyces cerevisiae/imunologia , Doenças dos Ovinos/terapia , Ovinos/imunologia , Administração Oral , Animais , Anticorpos Anti-Helmínticos/sangue , Citocinas/imunologia , Eosinófilos/imunologia , Fezes/parasitologia , Hemoncose/imunologia , Hemoncose/terapia , Haemonchus , Interações entre Hospedeiro e Microrganismos/imunologia , Imunoglobulina A/análise , Imunoglobulina G/sangue , Contagem de Leucócitos , Masculino , Contagem de Ovos de Parasitas , Ovinos/parasitologia , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/parasitologia
5.
Parasite Immunol ; 42(5): e12697, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31958344

RESUMO

Mechanisms of immune activation in effector cells during Haemonchus contortus infection in sheep are currently unknown. Microarray experiments have been performed on tissues of H contortus infected sheep of varying parasite resistance during early and late points of infection, but not in immune effector cells. The purpose of this study was to compare early gene activation in peripheral blood mononuclear cells (PBMC) from primed parasite susceptible (Suffolk) and resistant (St. Croix) sheep in response to H contortus larval antigen (HcLA). Peripheral blood mononuclear cells were cultured for 6 hours with HcLA, and RNA-sequencing was performed. St. Croix PBMC upregulated 499 unique genes in response to HcLA while Suffolk PBMC upregulated 130 unique genes and 25 genes were shared between the two breeds. St. Croix PBMC had increased expression of genes associated with immune function, signal transduction, response to stress and others. In addition, while mechanisms of innate recognition of H contortus are unknown, multiple pattern recognition receptors were found to be upregulated in St. Croix PBMC cultured with HcLA and none were found to be upregulated in Suffolk PBMC. These patterns of immune gene activation may contribute to St. Croix's rapid response and ability to resist H contortus infection.


Assuntos
Hemoncose/veterinária , Haemonchus/imunologia , Leucócitos Mononucleares/imunologia , RNA de Helmintos/genética , Doenças dos Ovinos/parasitologia , Animais , Cruzamento , Hemoncose/genética , Hemoncose/imunologia , Haemonchus/fisiologia , Larva/imunologia , Larva/fisiologia , Leucócitos Mononucleares/parasitologia , RNA de Helmintos/metabolismo , RNA-Seq , Ovinos , Doenças dos Ovinos/genética , Doenças dos Ovinos/imunologia , Carneiro Doméstico
6.
J Vet Sci ; 21(1): e5, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31940684

RESUMO

The major glycoproteins of bovine gammaherpesvirus 4 (BoHV-4) are gB, gH, gM, gL, and gp180 with gB, gH, and gp180 being the most glycosylated. These glycoproteins participate in cell binding while some act as neutralization targets. Glycosylation of these envelope proteins may be involved in virion protection against neutralization by antibodies. In infected cattle, BoHV-4 induces an immune response characterized by low neutralizing antibody levels or an absence of such antibodies. Therefore, virus seroneutralization in vitro cannot always be easily demonstrated. The aim of this study was to evaluate the neutralizing capacity of 2 Argentine BoHV-4 strains and to associate those findings with the gene expression profiles of the major envelope glycoproteins. Expression of genes coding for the envelope glycoproteins occurred earlier in cells infected with isolate 10/154 than in cells infected with strain 07/435, demonstrating a distinct difference between the strains. Differences in serological response can be attributed to differences in the expression of antigenic proteins or to post-translational modifications that mask neutralizing epitopes. Strain 07/435 induced significantly high titers of neutralizing antibodies in several animal species in addition to bovines. The most relevant serological differences were observed in adult animals. This is the first comprehensive analysis of the expression kinetics of genes coding for BoHV-4 glycoproteins in 2 Argentine strains (genotypes 1 and 2). The results further elucidate the BoHV-4 life cycle and may also help determine the genetic variability of the strains circulating in Argentina.


Assuntos
Antígenos Virais/análise , Infecções por Herpesviridae/veterinária , Herpesvirus Bovino 4/genética , Infecções Tumorais por Vírus/veterinária , Proteínas Virais/análise , Animais , Argentina , Bovinos , Doenças dos Bovinos/imunologia , Cervos , Feminino , Doenças das Cabras/imunologia , Doenças das Cabras/virologia , Cabras , Infecções por Herpesviridae/imunologia , Infecções por Herpesviridae/virologia , Herpesvirus Bovino 4/imunologia , Masculino , Ovinos , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/virologia , Transcrição Genética , Infecções Tumorais por Vírus/imunologia , Infecções Tumorais por Vírus/virologia
7.
Vet Microbiol ; 241: 108544, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31928696

RESUMO

Cattle, goats and sheep are dominant livestock species in sub-Saharan Africa, with sometimes limited information on the prevalence of major infectious diseases. Restrictions due to notifiable epizootics complicate the exchange of samples in surveillance studies and suggest that laboratory capacities should be established domestically. Bovine Coronavirus (BCoV) causes mainly enteric disease in cattle. Spillover to small ruminants is possible. Here we established BCoV serology based on a recombinant immunofluorescence assay for cattle, goats and sheep, and studied the seroprevalence of BCoV in these species in four different locations in the Greater Accra, Volta, Upper East, and Northern provinces of Ghana. The whole sampling and testing was organized and conducted by a veterinary school in Kumasi, Ashanti Region of Ghana. Among sampled sheep (n = 102), goats (n = 66), and cattle (n = 1495), the seroprevalence rates were 25.8 %, 43.1 % and 55.8 %. For cattle, seroprevalence was significantly higher on larger farms (82.2 % vs 17.8 %, comparing farms with >50 or <50 animals; p = 0.027). Highest prevalence was seen in the Northern province with dry climate, but no significant trend following the north-south gradient of sampling sites was detected. Our study identifies a considerable seroprevalence for BCoV in Ghana and provides further support for the spillover of BCoV to small ruminants in settings with mixed husbandry and limited separation between species.


Assuntos
Doenças dos Bovinos/epidemiologia , Infecções por Coronavirus/veterinária , Coronavirus Bovino/imunologia , Doenças das Cabras/epidemiologia , Doenças dos Ovinos/epidemiologia , Distribuição por Idade , Animais , Bovinos , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/transmissão , Doenças dos Bovinos/virologia , Análise por Conglomerados , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/transmissão , Estudos Transversais , Feminino , Gana/epidemiologia , Doenças das Cabras/imunologia , Doenças das Cabras/transmissão , Doenças das Cabras/virologia , Cabras , Lactação , Masculino , Análise Multivariada , Fatores de Risco , Estudos Soroepidemiológicos , Distribuição por Sexo , Ovinos , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/transmissão , Doenças dos Ovinos/virologia
8.
Parasite Immunol ; 42(1): e12679, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31630404

RESUMO

Host protective immunity to Haemonchus contortus (Hc) infection in parasite-resistant St. Croix (STC) sheep is initiated early and characterized by an influx of innate cells and robust interleukin-4 (IL-4) production, resulting in T-helper type 2 immune (Th2) responses. The purpose of these studies was to elucidate the source of early IL-4 production. Neutrophils were isolated from whole blood, and populations >98% purity were cultured with larval or adult antigen to access cytokine production. Interleukin-4 and IL-13 were measured in sample supernatant using an ovine-specific enzyme-linked immunosorbent assay (ELISA). Neutrophils exposed to HcLA peaked in IL-4 production at 30 minutes (STC, 3153.65 pg/mL and SUF, 4665.22 pg/mL). A similar trend was observed in IL-13 production by 6 hours (STC, 391.02 pg/mL and SUF, 419.6 pg/mL). Adult antigen stimulation resulted in low cytokine production when compared to HcLA stimulation (STC IL-4, 6.04 pg/mL and SUF, 8.05 pg/mL, respectively; STC IL-13, 10 pg/mL and 12.5 pg/mL; P < .001), and no breed differences were observed. Mixed immune cell assays revealed an ability of neutrophils to induce IL-4 production in peripheral blood mononuclear cell (PBMC). Taken together, these data implicate neutrophils as a potential effector cell responsible for Th2 initiation.


Assuntos
Antígenos de Helmintos/imunologia , Hemoncose/veterinária , Interleucina-13/imunologia , Interleucina-4/imunologia , Neutrófilos/imunologia , Doenças dos Ovinos/imunologia , Animais , Cruzamento , Ensaio de Imunoadsorção Enzimática , Hemoncose/imunologia , Hemoncose/parasitologia , Haemonchus/crescimento & desenvolvimento , Haemonchus/imunologia , Interleucina-13/biossíntese , Interleucina-4/biossíntese , Larva/imunologia , Leucócitos Mononucleares/imunologia , Ovinos , Doenças dos Ovinos/parasitologia , Carneiro Doméstico , Células Th2/imunologia
9.
Parasite Immunol ; 42(1): e12680, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31631347

RESUMO

Eosinophils are prominent effector cells in immune responses against gastrointestinal nematode infections in ruminants, but their in vivo role has been hard to establish in large animals. Interleukin-5 is a key cytokine in the induction and stimulation of anti-parasitic eosinophil responses. This study attempted to modulate the eosinophil response in sheep through vaccination with recombinant interleukin-5 (rIL-5) and determine the effect on subsequent Haemonchus contortus infection. Nematode-resistant Canaria Hair Breed (CHB) sheep vaccinated with rIL-5 in Quil-A adjuvant, had lower blood eosinophil counts and higher mean worm burdens than control sheep vaccinated with Quil-A adjuvant alone. In addition, adult worms in IL-5-vaccinated sheep were significantly longer with higher eggs in utero in female worms, supporting an active role of eosinophils against adult parasites in CHB sheep. These results confirm that eosinophils can play a direct role in effective control of H contortus infection in sheep and offer a new approach to study immune responses in ruminants.


Assuntos
Eosinófilos/imunologia , Hemoncose/veterinária , Haemonchus/imunologia , Doenças dos Ovinos/imunologia , Adjuvantes Imunológicos , Animais , Gastroenteropatias/parasitologia , Hemoncose/imunologia , Interleucina-5 , Masculino , Contagem de Ovos de Parasitas , Saponinas de Quilaia , Ovinos , Doenças dos Ovinos/parasitologia , Carneiro Doméstico , Vacinação
10.
J Immunol Res ; 2019: 3562672, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31815153

RESUMO

The immune response against Haemonchus contortus infections is primarily associated with the Th2 profile. However, the exact mechanisms associated with increased sheep resistance against this parasite remains poorly elucidated. The present study is aimed at evaluating mediators from the innate immune response in lambs of the Morada Nova Brazilian breed with contrasting H. contortus resistance phenotypes. Briefly, 287 lambs were characterized through fecal egg counts (FEC) and packed cell volume (PCV) after two independent experimental parasitic challenges with 4,000 H. contortus L3. 20 extreme resistance phenotypes (10 most resistant and 10 most susceptible) were selected, subjected to a third artificial infection with 4,000 L3, and euthanized 7 days later. Tissue samples were collected from abomasal fundic and pyloric mucosa and abomasal lymph nodes. Blood samples were collected at days 0 and 7 of the third parasitic challenge. RNA was extracted from tissue and blood samples for relative quantification of innate immune-related genes by RT-qPCR. For the abomasal fundic mucosa, increased TNFα and IL1ß expression levels (P < 0.05) were found in the susceptible animals, while resistant animals had IL33 superiorly expressed (P < 0.05). Higher levels (P < 0.05) of TLR2 and CFI were found in the abomasal pyloric mucosa of resistant animals. TNFα was at higher levels (P < 0.05) in the blood of susceptible lambs, at day 0 of the third artificial infection. The exacerbated proinflammatory response observed in susceptible animals, at both local and systemic levels, may be a consequence of high H. contortus parasitism. This hypothesis is corroborated by the higher blood levels of TNFα before the onset of infection, which probably remained elevated from the previous parasitic challenges. On the other hand, resistant lambs had an enhanced response mediated by TLR recognition and complement activation. Nevertheless, this is the first study to directly associate sheep parasitic resistance with IL33, an innate trigger of the Th2-polarized response.


Assuntos
Aminopeptidases/genética , Resistência à Doença/genética , Hemoncose/imunologia , Imunidade Inata , Doenças dos Ovinos/imunologia , Receptor 2 Toll-Like/genética , Aminopeptidases/imunologia , Animais , Fezes/parasitologia , Feminino , Mucosa Gástrica/imunologia , Mucosa Gástrica/patologia , Expressão Gênica , Hemoncose/genética , Hemoncose/parasitologia , Hemoncose/patologia , Haemonchus/imunologia , Haemonchus/patogenicidade , Interleucina-1beta/genética , Interleucina-1beta/imunologia , Interleucina-33/genética , Interleucina-33/imunologia , Linfonodos/imunologia , Linfonodos/patologia , Contagem de Ovos de Parasitas , Fenótipo , Ovinos , Doenças dos Ovinos/genética , Doenças dos Ovinos/parasitologia , Doenças dos Ovinos/patologia , Células Th2/imunologia , Células Th2/parasitologia , Células Th2/patologia , Receptor 2 Toll-Like/imunologia , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia
11.
Vet Res ; 50(1): 104, 2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31783921

RESUMO

Understanding the immunological basis of resistance to gastrointestinal nematode infections in livestock is important in order to develop novel methods of parasite control such as vaccination or genetic selection for parasite resistance. The present study aimed to investigate differences in immune response between parasite resistant Santa Ines and susceptible Ile de France sheep breeds to natural Haemonchus contortus infection. Parasitological parameters, humoral immunity, local and circulating cellular immune responses were evaluated in 19 Santa Ines and 19 Ile de France lambs undergoing different anthelmintic treatments regimens: suppressive treatments (SUP) or targeted selective treatments (TST) over a 5-month grazing period. Santa Ines lambs had significantly lower Haemonchus faecal egg count and worm burden compared to Ile de France regardless of treatment regime. In addition, circulating blood eosinophils count and parasite-specific IgG levels were significantly higher and more rapidly induced in Santa Ines lambs. Abomasal immune responses were generally greater in the resistant breed, which had significantly higher levels of parasite-specific IgA in mucus, and elevated number of globule leukocytes and CD3+ T cells within the abomasal mucosal. Furthermore, numbers of POU2F3+ epithelial cells, a tuft-cell specific transcription factor, were also elevated in the Santa Ines breed, suggesting that this breed is better able to initiate T-helper type 2 immune responses within the abomasum. In conclusion, the differential immunological responses detailed here are relevant to understanding resistance to gastrointestinal nematodes in other host breeds, as well as to resistance breeding as a sustainable control approach for parasitic infections.


Assuntos
Imunidade Adaptativa , Suscetibilidade a Doenças/veterinária , Gastroenteropatias/veterinária , Hemoncose/veterinária , Haemonchus/fisiologia , Imunidade Inata , Doenças dos Ovinos/imunologia , Animais , Brasil , Gastroenteropatias/imunologia , Gastroenteropatias/parasitologia , Hemoncose/imunologia , Hemoncose/parasitologia , Imunidade Celular , Imunidade Humoral , Ovinos , Doenças dos Ovinos/parasitologia , Carneiro Doméstico
12.
Sci Rep ; 9(1): 19579, 2019 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-31862904

RESUMO

Gastrointestinal nematode infections, including Haemonchus contortus, are one of the main causes of economic losses to ovine farmers worldwide. In order to contribute to the control of nematode infections and avoid parasite spreading we generated divergent resistant and susceptible sheep breeds and evaluated the adaptive immunity of these animals developed upon experimental infection against H. contortus. The selection of resistant or susceptible animals from the Corriedale Breed has been based on Expected Progeny Differences for faecal egg counts per gram. Furthermore, animals from the resistant Corriedale line were inseminated with imported semen from Australian Rylington Merino rams. Thus, the objective of this work was to analyze the adaptive immune response in both susceptible and resistant obtained lambs. Our results indicate that there is a potent parasite-specific local and systemic immune response in resistant animals and that although susceptible lambs can produce high levels of IgA antibodies during the infection, their antibody response is delayed which, together with an impaired specific-Th2 response, does not contribute to initial parasite elimination. Our results shed light into the immune mechanisms that mediate resistance to H. contortus and could constitute important assets to sheep farmers, not only as a means to detect resistance, but also to enhance the efficiency of selection in stud flocks.


Assuntos
Haemonchus/patogenicidade , Imunidade Adaptativa/fisiologia , Animais , Formação de Anticorpos/fisiologia , Feminino , Haemonchus/imunologia , Imunoglobulina A/metabolismo , Masculino , Ovinos , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/microbiologia , Células Th2/metabolismo
13.
Vet Parasitol ; 276: 108994, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31778941

RESUMO

Neospora caninum is a protozoan parasite (Phylum Apicomplexa) that has been recently suggested as a relevant cause of reproductive disorders in small ruminants. The aim of the present study is to develop and validate a new serological test based on time resolved fluorescency using N. caninum GRA7 recombinant antigen (GRA7-TRFIA) for the detection of N. caninum antibodies in sheep. A total of 346 serum samples (208 from experimentally infected sheep, 117 from a dairy farm with a previous history of Neospora-associated abortion, and 21 negative sera) were used. The validation of the new assay was performed by the evaluation of assay precision, analytical sensitivity (Se), accuracy and cross reactivity. In the experimentally infected sheep, antibody kinetics was compared between GRA7-TRFIA and an in house N. caninum tachyzoite soluble extract-based ELISA (NcSALUVET ELISA) by Wilcoxon matched-pairs signed rank test. The cut-off and diagnostic Se and specificity (Sp) of GRA7-TRFIA was estimated by ROC analysis with field samples. In addition, concordance and correlation between GRA7-TRFIA and a commercial ELISA and NcSALUVET ELISA were assessed by kappa value and Spearman correlation coefficient, respectively. Overall, GRA7-TRFIA showed an adequate precision, analytical Se and accuracy to detect anti-N. caninum antibodies in ovine serum, and no cross reactivity with the closely related protozoan Toxoplasma gondii. In naturally infected sheep, 100% Se and 95.35% Sp were obtained for a cut-off point of 62.68 Units of Fluorometry for N. caninum (UFN). Moreover, GRA7-TRFIA allowed earlier detection of N. caninum infection than NcSALUVET ELISA in experimentally infected sheep.


Assuntos
Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/imunologia , Coccidiose/veterinária , Neospora/imunologia , Doenças dos Ovinos/imunologia , Animais , Coccidiose/imunologia , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Imunoensaio de Fluorescência por Polarização , Fluorometria/veterinária , Imunoglobulina G/sangue , Sensibilidade e Especificidade , Ovinos , Doenças dos Ovinos/parasitologia
14.
BMC Vet Res ; 15(1): 426, 2019 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-31779623

RESUMO

BACKGROUND: Schmallenberg virus (SBV) is a midge borne virus of cattle and sheep. Infection is typically asymptomatic in adult sheep but fetal infection during pregnancy can result in abortion, stillbirth, neurological disorders and malformations of variable severity in newborn animals. It was first identified in Germany and the Netherlands in 2011 and then circulated throughout Europe in 2012 and 2013. Circulation in subsequent years was low or non-existent until summer and autumn 2016, leading to an increased incidence of deformed newborn lambs and calves in 2016-17. This study reports SBV circulation in October 2016 within a group of 24 ewes and 13 rams. The ewes were monitored at 3 times points over an 11 week period (September to December 2016). RESULTS: Most ewes displayed an increase in SBV VNT with antibody titre increases greater in older, previously exposed ewes. Two ewes had SBV RNA detectable by RT-qPCR, one on 30/09/16 and one on 04/11/16. Of these ewes, one had detectable serum SBV RNA (indicating viraemia) despite pre-existing antibody. The rams had been previously vaccinated with a commercial inactivated SBV vaccine, they showed minimal neutralising antibody titres against SBV 8 months post-vaccination and all displayed increased titre in October 2016. CONCLUSION: This data suggests that SBV circulated for a minimum period of 5 weeks in September to October 2016 in central England. Ewes previously exposed to virus showed an enhanced antibody response compared to naïve animals. Pre-existing antibody titre did not prevent re-infection in at least one animal, implying immunity to SBV upon natural exposure may not be life-long. In addition, data suggests that immunity provided by killed adjuvanted SBV vaccines only provides short term protection (< 8 months) from virus.


Assuntos
Infecções por Bunyaviridae/veterinária , Orthobunyavirus/imunologia , Doenças dos Ovinos/imunologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Infecções por Bunyaviridae/sangue , Infecções por Bunyaviridae/imunologia , Inglaterra/epidemiologia , Feminino , Masculino , RNA Viral/sangue , Ovinos , Doenças dos Ovinos/virologia , Carneiro Doméstico , Vacinação
15.
BMC Vet Res ; 15(1): 399, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31694666

RESUMO

BACKGROUND: TBE is an important tick-borne viral zoonosis in Europe and some parts of Asia. Humans can become infected by tick bite and in some cases also by consumption of nonpasteurized raw milk and raw milk products from ruminants. Serological investigations of milking flocks can help to assess the risk of TBEV infection for humans. 735 blood samples from 50 goat flocks from four federal states of Germany were tested by TBEV-VNT to assess a potential risk for TBEV infection. There are some gaps in the knowledge about immunity in animals, for example with regard to the longevity of TBEV immunity. Two goats and two sheep were immunized and TBEV antibody titers could be detected for up to 7 years. Furthermore, nothing is known about a possible long-lasting immunological memory that could quickly be reactivated by an additional contact to TBEV. Seven years after the first immunization two goats and two sheep as well as two naïve goats and two sheep were boostered and TBEV antibody titers followed. RESULTS: Only one sample in each of the three states was TBEV-antibody positive (VNT), albeit with low titers. However, in Baden-Württemberg seven samples were positive, among them four goats of the same flock. TBEV-antibody positive titers were detected in goats for up to 6 years and 10 months, in sheep for up to 4 years and 7 months. Seven years after immunization a clear immunological recall occurred in response to administration of one dose of vaccine in two goats and two sheep. CONCLUSION: It can be concluded that in the tested flocks the risk of an alimentary TBEV infection was low. However, in one single flock a considerably higher risk must be assumed. Antibody titers in goats and sheep can last very long after contact to TBEV, albeit at a low level. This should be taken into consideration in cases where the risk of an alimentary infection is assessed in a flock by serological investigations. The immunological recall gives rise to the suspicion that the immunological memory after a first contact to TBEV lasts for many years, probably lifelong.


Assuntos
Anticorpos Antivirais/sangue , Vírus da Encefalite Transmitidos por Carrapatos/imunologia , Encefalite Transmitida por Carrapatos/veterinária , Doenças das Cabras/virologia , Doenças dos Ovinos/virologia , Animais , Vírus da Encefalite Transmitidos por Carrapatos/isolamento & purificação , Encefalite Transmitida por Carrapatos/imunologia , Feminino , Alemanha/epidemiologia , Doenças das Cabras/imunologia , Cabras , Ovinos , Doenças dos Ovinos/imunologia , Vacinas/farmacologia
16.
Vet Immunol Immunopathol ; 218: 109936, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31590072

RESUMO

Anaplasma phagocytophilum is a tick borne bacterium, causing disease in sheep and other mammals, including humans. The bacterium has great economic and animal welfare implications for sheep husbandry in Northern Europe. With the prospect of a warmer and more humid climate, the vector availability will likely increase, resulting in a higher prevalence of A. phagocytophilum. The current preventive measures, as pyrethroids acting on ticks or long acting antibiotics controlling bacterial infection, are suboptimal for prevention of the disease in sheep. Recently, the increased awareness on antibiotic- and pyrethorid resistance, is driving the search for a new prophylactic approach in sheep against A. phagocytophilum. Previous studies have used an attenuated vaccine, which gave insufficient protection from challenge with live bacteria. Other studies have focused on bacterial membrane surface proteins like Asp14 and OmpA. An animal study using homologous proteins to Asp14 and OmpA of A. marginale, showed no protective effect in heifers. In the current study, recombinant proteins of Asp14 (rAsp14) and OmpA (rOmpA) of A. phagocytophilum were produced and prepared as a vaccine for sheep. Ten lambs were vaccinated twice with an adjuvant emulsified with rAsp14 or rOmpA, three weeks apart and challenged with a live strain of A. phagocytophilum (GenBank acc.nr M73220) on day 42. The control group consisted of five lambs injected twice with PBS and adjuvant. Hematology, real time qPCR, immunodiagnostics and flow cytometric analyses of peripheral blood mononuclear cells were performed. Vaccinated lambs responded with clinical signs of A.phagocytophilum infection after challenge and bacterial load in the vaccinated group was not reduced compared to the control group. rAsp14 vaccinated lambs generated an antibody response against the vaccine, but a clear specificity for rAsp14 could not be established. rOmpA-vaccinated lambs developed a strong specific antibody response on days 28 after vaccination and 14 days post-challenge. Immunofluorescent staining and flow cytometric analysis of peripheral blood mononuclear monocytes revealed no difference between the three groups, but the percentage of CD4+, CD8+, γδ TcR+, λ-Light chain+, CD11b+, CD14+ and MHC II+ cells, within the groups changed during the study, most likely due to the adjuvant or challenge with the bacterium. Although an antigen specific antibody response could be detected against rOmpA and possibly rAsp14, the vaccines seemed to be ineffective in reducing clinical signs and bacterial load caused by A. phagocytophilum. This is the first animal study with recombinant Asp14 and OmpA aimed at obtaining clinical protection against A. phagocytophilum in sheep.


Assuntos
Anticorpos Antibacterianos/sangue , Proteínas da Membrana Bacteriana Externa/imunologia , Proteínas de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Ehrlichiose/veterinária , Doenças dos Ovinos/prevenção & controle , Anaplasma phagocytophilum , Animais , Proteínas da Membrana Bacteriana Externa/genética , Proteínas de Bactérias/genética , Vacinas Bacterianas/genética , Ehrlichiose/imunologia , Ehrlichiose/prevenção & controle , Ovinos , Doenças dos Ovinos/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia
17.
Science ; 365(6459): 1296-1298, 2019 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-31604239

RESUMO

Our understanding of the deterioration in immune function in old age-immunosenescence-derives principally from studies of modern human populations and laboratory animals. The generality and significance of this process for systems experiencing complex, natural infections and environmental challenges are unknown. Here, we show that late-life declines in an important immune marker of resistance to helminth parasites in wild Soay sheep predict overwinter mortality. We found senescence in circulating antibody levels against a highly prevalent nematode worm, which was associated with reduced adult survival probability, independent of changes in body weight. These findings establish a role for immunosenescence in the ecology and evolution of natural populations.


Assuntos
Envelhecimento/imunologia , Resistência à Doença/imunologia , Helmintíase Animal/imunologia , Imunossenescência , Ovinos/imunologia , Ovinos/parasitologia , Animais , Anticorpos Anti-Helmínticos/sangue , Peso Corporal , Feminino , Imunoglobulina G/sangue , Modelos Lineares , Masculino , Contagem de Ovos de Parasitas , Carga Parasitária , Escócia , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/parasitologia , Análise de Sobrevida
18.
Int J Parasitol ; 49(12): 901-910, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31585121

RESUMO

Global livestock production is facing serious new challenges, including climate-driven changes in parasite epidemiology, and anthelmintic resistance, driving a need for non-chemotherapeutic methods of parasite control. Selecting for genetic resistance to gastrointestinal nematode infection could reduce reliance on chemical intervention and mitigate increases in parasite challenge due to climate change. Ewes of the composite Exlana breed with a range of estimated breeding values (EBVs) based on nematode faecal egg counts (FECs) were monitored during the peri-parturient period on two farms in southwestern England. Ewes with low EBVs ("resistant") had lower FECs during the peri-parturient period than those with high EBVs ("susceptible"): the mean FEC was reduced by 23% and 34% on Farms 1 and 2, respectively, while the peak FEC was reduced by 30% and 37%, respectively. Neither EBV nor FEC were correlated with key performance indicators (estimated milk yield, measured indirectly using 8 week lamb weight, and ewe weight loss during lactation). Simulations predict that the reduced FECs of resistant ewes would result in a comparable reduction in infection pressure (arising from eggs shed by ewes) for their lambs. Furthermore, although the reduced FECs observed were modest, simulations predicted that selecting for nematode resistance in ewes could largely offset predicted future climate-driven increases in pasture infectivity arising from eggs contributed by these ewes. Selective breeding of the maternal line for nematode resistance therefore has potential epidemiological benefits by reducing pasture infectivity early in the grazing season and alleviating the need for anthelmintic treatment of ewes during the peri-parturient period, thus reducing selection pressure for anthelmintic resistance. These benefits are magnified under predicted future climate change. The maternal line warrants more attention in selective breeding programmes for nematode resistance.


Assuntos
Resistência à Doença , Fezes/parasitologia , Enteropatias Parasitárias/veterinária , Nematoides/crescimento & desenvolvimento , Infecções por Nematoides/veterinária , Doenças dos Ovinos/parasitologia , Ovinos/parasitologia , Animais , Mudança Climática , Inglaterra , Helmintíase/imunologia , Helmintíase/parasitologia , Enteropatias Parasitárias/imunologia , Enteropatias Parasitárias/parasitologia , Nematoides/imunologia , Infecções por Nematoides/imunologia , Infecções por Nematoides/parasitologia , Contagem de Ovos de Parasitas , Seleção Artificial , Doenças dos Ovinos/imunologia
19.
J Anim Sci ; 97(11): 4428-4444, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31541548

RESUMO

The aim of this study was to identify for the first time single nucleotide polymorphisms (SNPs) associated with Haemonchus contortus resistance in Florida Native sheep, using a targeted sequencing approach. One hundred and fifty-three lambs were evaluated in this study. At the start of the trial, phenotypic records for fecal egg count (FEC), FAMACHA score, body condition score (BCS), and weight were recorded and deworming of sheep with levamisole (18 mg/kg of body weight) was performed. Ten days post-deworming (baseline) and 28 d post-baseline, a full hematogram of each sheep was obtained and FEC, FAMACHA score, BCS, and weight were assessed. Average daily gain was calculated at the end of the trial. Out of 153 animals, 100 sheep were selected for genotyping using a targeted sequencing approach. Targeted sequencing panel included 100 candidate genes for immune response against H. contortus. SNPs were discarded if call rate <95% and minor allele frequency ≤0.05. A mixed model was used to analyze the response variables and included the identity by state matrix to control for population structure. A contemporary group (age, group, and sex) was included as fixed effect. Bonferroni correction was used to control for multiple testing. Eighteen SNPs on chromosomes 1, 2, 3, 4, 6, 7, 11, 15, 18, 20, 24, and 26 were significant for different traits. Our results suggest that loci related to Th17, Treg, and Th2 responses play an important role in the expression of resistant phenotypes. Several genes including ITGA4, MUC15, TLR3, PCDH7, CFI, CXCL10, TNF, CCL26, STAT3, GPX2, IL2RB, and STAT6 were identified as potential markers for resistance to natural H. contortus exposure. This is the first study that evaluates potential genetic markers for H. contortus resistance in Florida Native sheep.


Assuntos
Resistência à Doença/genética , Estudo de Associação Genômica Ampla/veterinária , Hemoncose/veterinária , Haemonchus/imunologia , Doenças dos Ovinos/imunologia , Animais , Peso Corporal , Fezes/parasitologia , Feminino , Florida , Técnicas de Genotipagem/veterinária , Hemoncose/imunologia , Hemoncose/parasitologia , Masculino , Contagem de Ovos de Parasitas/veterinária , Fenótipo , Ovinos , Doenças dos Ovinos/parasitologia , Linfócitos T Reguladores/imunologia
20.
Vet Immunol Immunopathol ; 217: 109941, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31550657

RESUMO

DNA vaccination in large animals has often been associated with poor immunogenicity, consequently several approaches have been evaluated to enhance its efficacy. Here, we tested a cDNA encoding a phosphoglycerate kinase from Fasciola hepatica (cDNA-FhPGK/pCMV) as a vaccine against ovine fasciolosis and investigated whether a DNA prime/protein boost regime or CTLA-4 (cytotoxic lymphocyte antigen 4) mediated targeting improved DNA vaccine efficacy. No statistically significant differences in the cellular responses were seen in either vaccine trial when compared with the respective control groups. However, specific antibody responses were considerably enhanced in DNA primed/protein boosted sheep, but not among CTLA-4 targeted cDNA-FhPGK/pCMV vaccinated animals. Nevertheless, increased titers of specific IgG1 did not contribute to protection against infection, with no differences in liver fluke recoveries reported. If DNA vaccines against fasciolosis in target species are to reach the market one day, more research in this area is needed.


Assuntos
Antígeno CTLA-4/imunologia , Fasciola hepatica/enzimologia , Fasciolíase/veterinária , Fosfoglicerato Quinase/imunologia , Vacinação/veterinária , Vacinas de DNA/imunologia , Animais , Fasciola hepatica/imunologia , Fasciolíase/prevenção & controle , Proteínas de Helminto/imunologia , Esquemas de Imunização , Masculino , Ovinos/parasitologia , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/prevenção & controle , Falha de Tratamento , Potência de Vacina
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