RESUMO
The ovine maedi-visna virus (MVV) and caprine arthritis-encephalitis virus (CAEV) are small ruminant lentiviruses (SRLVs) with striking genetic and structural similarities. The presence of SRLV in Mongolian sheep and goats was serologically demonstrated more than a decade ago; however, the viral genotype remains unknown. In total, 329 blood samples were collected from two sheep breeds (i.e., Khalkha and Sumber) in Tov, Govisumber, Arkhangay, Dornogovi, Zavkhan, and Sukhbaatar provinces, Mongolia. Serological and phylogenetic analyses were performed regardless of any apparent clinical signs, although most of the animals appeared healthy. All sheep in three of the six provinces were seronegative, whereas the seroprevalence in the Tov, Govisumber, and Zavkhan provinces averaged 7.9%. Genomic DNA from seropositive animals was tested using hemi-nested polymerase chain reaction, and sub-genomic SRLV sequences were determined from nine samples. Mongolian SRLV sequences clustered within the divergent subtype A22, which was previously found only in Fertile Crescent regions, including Lebanon, Jordan, and Iran, where the first sheep-domestication (Ovis aries) occurred. According to the phylogenetic analysis, genotype A has two ancestors from the ancient Fertile Crescent: (1) Turkish strains and (2) Iranian, Jordanian, and Lebanese strains. The first ancestor spread westward, whereas the second spread eastward, ultimately reaching Mongolia.
Assuntos
Genótipo , Infecções por Lentivirus , Filogenia , Doenças dos Ovinos , Animais , Ovinos/virologia , Mongólia/epidemiologia , Infecções por Lentivirus/veterinária , Infecções por Lentivirus/virologia , Infecções por Lentivirus/epidemiologia , Doenças dos Ovinos/virologia , Doenças dos Ovinos/epidemiologia , Vírus Visna-Maedi/genética , Vírus Visna-Maedi/classificação , Vírus Visna-Maedi/isolamento & purificação , Vírus da Artrite-Encefalite Caprina/genética , Vírus da Artrite-Encefalite Caprina/classificação , Vírus da Artrite-Encefalite Caprina/isolamento & purificação , Estudos SoroepidemiológicosRESUMO
Acute demyelinating leucoencephalomyelitis was the most conspicuous microscopic change in the brain and spinal cord of kids infected with caprine arthritis encephalitis virus (CAEV). TUNEL positivity and labelling of anti-bax and anti-caspases-3, -8 and -9 were found in a distinct population of glial cells, mainly at the edges of the demyelinated plaques and perivascular areas and, to a lesser extent, in neurons. Double labelling revealed that most of these apoptotic cells in the demyelinated plaques were astrocytes and a few were oligodendroglia. In contrast, expression of bcl-2, an anti-apoptotic protein, was found mainly in neurons of the brainstem and cerebellum and motor neurons of the spinal cord, but was restricted in glial cells. These results suggest that apoptosis plays an important role in the pathogenesis of CAE demyelinating encephalitis.
Assuntos
Vírus da Artrite-Encefalite Caprina , Encefalite , Infecções por Lentivirus , Animais , Vírus da Artrite-Encefalite Caprina/fisiologia , Encéfalo/patologia , Encefalite/veterinária , Apoptose , Neuroglia/patologia , Infecções por Lentivirus/patologia , Infecções por Lentivirus/veterináriaRESUMO
Jaagsiekte retrovirus (JSRV)-induced ovine pulmonary adenocarcinoma (OPA) is an important ovine respiratory disease in Switzerland. Furthermore, ovine lungs with OPA frequently exhibited lesions suggestive of maedi-visna virus (MVV) or caprine arthritis encephalitis virus (CAEV) infection, indicating that co-morbidities might occur. Lungs and pulmonary lymph nodes were sampled from suspected OPA cases, inflammatory lung lesions and control lungs (total of 110 cases). Tissues were (a) processed for histology and immunohistochemistry (IHC), and (b) underwent DNA extraction and real-time PCR for JSRV, MVV and CAEV. Peptide sequences were used to generate virus-specific customized polyclonal antibodies. PCR-positive OPA cases and formalin-fixed and paraffin-embedded MVV- and CAEV-infected synovial cell pellets served as positive controls. Fifty-two lungs were histologically diagnosed with OPA. Histological evidence of MVV/CAEV infection was detected in 25 lungs. JSRV was detected by PCR in 84% of the suspected OPA cases; six were co-infected with MVV and one with CAEV. MVV was detected by PCR in 14 cases, and four lungs were positive for CAEV. Three lungs had MVV/CAEV co-infection. In IHC, JSRV was detected in 91% of the PCR-positive cases, whereas MVV and CAEV immunoreactivity was seen in all PCR-positive lungs. Although PCR showed a higher sensitivity compared to IHC, the combined approach allows for investigations on viral cell tropism and pathogenic processes in co-morbidities, including their potential interdependency. Furthermore, an immunohistochemical tool for specific differentiation of MVV and/or CAEV infection was implemented.
Assuntos
Vírus da Artrite-Encefalite Caprina , Coinfecção , Retrovirus Jaagsiekte de Ovinos , Infecções por Retroviridae , Ovinos , Animais , Retroviridae , Coinfecção/veterinária , Ruminantes , Anticorpos , Reação em Cadeia da Polimerase em Tempo RealRESUMO
Serum samples (n = 1532) were collected between May 2011 to April 2012 from goats from 76 herds (49 from dairy farms and 27 herds for genetic improvement) from three geographical regions from the state of Pernambuco, Brazil: Zona da Mata, Agreste, and Sertão. Samples were processed using agar gel immunodiffusion test, with p28 CAEV antigen. The objective was to determine the risk factors for small ruminant lentivirus (SRLV) in dairy goats and goats with high genetic value. Overall, seroprevalence was 13.7% (210/1532) [95% CI: 12-15.4%] in animals and 67.1% (51/76) [95% CI: 56.5%- 77.7%] in herds. In dairy farms the seroprevalence was 73.5% (36/49) [95% CI: 61.1%- 85.8%], and in properties with animals of high genetic value it was 55.6% (15/27) [95% CI: 36.8%- 74.3%]. Robust Poisson regression analysis adjusted by the random effect of the herd showed that risk factors were: importing bucks from another Brazilian state (prevalence ratio [PR] = 4.73 [95% CI: 2.05; 10.88]), not isolating sick animals (PR = 3.27 [95% CI: 2.24; 4.76]), and participating in fairs/animal crowding (PR = 1.52 [95% CI: 1.09; 2.11]). Prevalence results show that SRLV is present in caprine herds in the state of Pernambuco and identified risk factors are strongly related to animal transit. Considering the epidemiological situation, the first step for mitigating the consequences of this disease would be controlling animal transit.
Assuntos
Vírus da Artrite-Encefalite Caprina , Doenças das Cabras , Infecções por Lentivirus , Animais , Cabras , Brasil/epidemiologia , Estudos Soroepidemiológicos , Infecções por Lentivirus/epidemiologia , Infecções por Lentivirus/veterináriaRESUMO
South Tyrol has implemented, in 2007, a mandatory eradication program against Caprine Arthritis Encephalitis Virus (CAEV), a virus known to cause economic losses related to decreases in milk production and milk quality in goats, along with poor animal welfare and premature death. After a great initial decrease in the seroprevalence, the program has reached a tailing phase with scattered positivities. Potential risk factors associated with the multispecies farming system, a traditional approach in South Tyrol, are evaluated in this study, in order to better understand some of the potential causes leading to the tailing phenomenon. A statistically significant number of farms was selected for the present study, based on the risk factors evaluated. Even though there is no statistically significant association between the practices evaluated and the incidence of infection, the authors believe that it is important to highlight potential risks that may threaten the outcome of this eradication program.
Assuntos
Agricultura/normas , Vírus da Artrite-Encefalite Caprina/patogenicidade , Erradicação de Doenças/normas , Doenças das Cabras/epidemiologia , Infecções por Lentivirus/epidemiologia , Infecções por Lentivirus/veterinária , Agricultura/métodos , Animais , Erradicação de Doenças/métodos , Doenças das Cabras/etiologia , Cabras/virologia , Incidência , Itália/epidemiologia , Infecções por Lentivirus/etiologia , Fatores de Risco , Estudos SoroepidemiológicosRESUMO
Small ruminant lentiviruses (SRLV) are economically important viral pathogens of sheep and goats. SRLV infection may interfere in the innate and adaptive immunity of the host, and genes associated with resistance or susceptibility to infection with SRLV have not been fully recognized. The presence of animals with relatively high and low proviral load suggests that some host factors are involved in the control of virus replication. To better understand the role of the genes involved in the host response to SRLV infection, RNA sequencing (RNA-seq) method was used to compare whole gene expression profiles in goats carrying both a high (HPL) and low (LPL) proviral load of SRLV and uninfected animals. Data enabled the identification of 1130 significant differentially expressed genes (DEGs) between control and LPL groups: 411 between control and HPL groups and 1434 DEGs between HPL and LPL groups. DEGs detected between the control group and groups with a proviral load were found to be significantly enriched in several gene ontology (GO) terms, including an integral component of membrane, extracellular region, response to growth factor, inflammatory and innate immune response, transmembrane signaling receptor activity, myeloid differentiation primary response gene 88 (MyD88)-dependent toll-like receptor signaling pathway as well as regulation of cytokine secretion. Our results also demonstrated significant deregulation of selected pathways in response to viral infection. The presence of SRLV proviral load in blood resulted in the modification of gene expression belonging to the toll-like receptor signaling pathway, the tumor necrosis factor (TNF) signaling pathway, the cytokine-cytokine receptor interaction, the phagosome, the Ras signaling pathway, the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) (PI3K-Akt) signaling pathway and rheumatoid arthritis. It is worth mentioning that the most predominant in all pathways were genes represented by toll-like receptors, tubulins, growth factors as well as interferon gamma receptors. DEGs detected between LPL and HPL groups were found to have significantly enriched regulation of signaling receptor activity, the response to toxic substances, nicotinamide adenine dinucleotide (NADH) dehydrogenase complex assembly, cytokine production, vesicle, and vacuole organization. In turn, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway tool classified DEGs that enrich molecular processes such as B and T-cell receptor signaling pathways, natural killer cell-mediated cytotoxicity, Fc gamma R-mediated phagocytosis, toll-like receptor signaling pathways, TNF, mammalian target of rapamycin (mTOR) signaling and forkhead box O (Foxo) signaling pathways, etc. Our data indicate that changes in SRLV proviral load induced altered expression of genes related to different biological processes such as immune response, inflammation, cell locomotion, and cytokine production. These findings provide significant insights into defense mechanisms against SRLV infection. Furthermore, these data can be useful to develop strategies against SRLV infection by selection of animals with reduced SRLV proviral concentration that may lead to a reduction in the spread of the virus.
Assuntos
Vírus da Artrite-Encefalite Caprina/genética , Cabras/virologia , Vírus Visna-Maedi/genética , Imunidade Adaptativa/genética , Animais , Expressão Gênica/genética , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica/genética , Doenças das Cabras/virologia , Cabras/genética , Interações entre Hospedeiro e Microrganismos/genética , Imunidade Inata/genética , Infecções por Lentivirus/veterinária , Lentivirus Ovinos-Caprinos/genética , Provírus/genética , Análise de Sequência de RNA , Transcriptoma/genética , Carga Viral/métodos , Replicação ViralRESUMO
Maedi-Visna-like genotype A strains and Caprine arthritis encephaltis-like genotype B strains are small ruminant lentiviruses (SRLV) which, for incompletely understood reasons, appear to be more virulent in sheep and goats, respectively. A 9-month in vivo infection experiment using Belgian genotype A and B SRLV strains showed that almost all homologous (genotype A in sheep; genotype B in goats) and heterologous (genotype A in goats; genotype B in sheep) intratracheal inoculations resulted in productive infection. No differences in viremia and time to seroconversion were observed between homologous and heterologous infections. Higher viral loads and more severe lesions in the mammary gland and lung were however detected at 9 months post homologous compared to heterologous infection which coincided with strongly increased IFN-γ mRNA expression levels upon homologous infection. Pepscan analysis revealed a strong antibody response against immune-dominant regions of the capsid and surface proteins upon homologous infection, which was absent after heterologous infection. These results inversely correlated with protection against virus replication in target organs and observed histopathological lesions, and thus require an in-depth evaluation of a potential role of antibody dependent enhancement in SRLV infection. Finally, no horizontal intra- and cross-species SRLV transmission to contact animals was detected.
Assuntos
Vírus da Artrite-Encefalite Caprina/fisiologia , Genótipo , Doenças das Cabras/imunologia , Cabras , Imunidade Humoral , Pneumonia Intersticial Progressiva dos Ovinos/imunologia , Ovinos , Replicação Viral/imunologia , Vírus Visna-Maedi/fisiologia , Animais , Anticorpos Antivirais/imunologia , Feminino , Doenças das Cabras/genética , Doenças das Cabras/patologia , Doenças das Cabras/virologia , Cabras/imunologia , Cabras/virologia , Pulmão/imunologia , Pulmão/patologia , Pulmão/virologia , Glândulas Mamárias Animais/imunologia , Glândulas Mamárias Animais/patologia , Glândulas Mamárias Animais/virologia , Pneumonia Intersticial Progressiva dos Ovinos/genética , Pneumonia Intersticial Progressiva dos Ovinos/patologia , Pneumonia Intersticial Progressiva dos Ovinos/virologia , Ovinos/imunologia , Ovinos/virologia , Especificidade da Espécie , Carga Viral/imunologiaRESUMO
Small ruminant lentiviruses (SRLVs) infections lead to chronic diseases and remarkable economic losses undermining health and welfare of animals and the sustainability of farms. Early and definite diagnosis of SRLVs infections is the cornerstone for any control and eradication efforts; however, a "gold standard" test and/or diagnostic protocols with extensive applicability have yet to be developed. The main challenges preventing the development of a universally accepted diagnostic tool with sufficient sensitivity, specificity, and accuracy to be integrated in SRLVs control programs are the genetic variability of SRLVs associated with mutations, recombination, and cross-species transmission and the peculiarities of small ruminants' humoral immune response regarding late seroconversion, as well as intermittent and epitope-specific antibody production. The objectives of this review paper were to summarize the available serological and molecular assays for the diagnosis of SRLVs, to highlight their diagnostic performance emphasizing on advantages and drawbacks of their application, and to discuss current and future perspectives, challenges, limitations and impacts regarding the development of reliable and efficient tools for the diagnosis of SRLVs infections.
Assuntos
Infecções por Lentivirus/diagnóstico , Infecções por Lentivirus/imunologia , Lentivirus/genética , Lentivirus/imunologia , Ruminantes/virologia , Testes Sorológicos/veterinária , Animais , Vírus da Artrite-Encefalite Caprina/genética , Vírus da Artrite-Encefalite Caprina/imunologia , Doenças das Cabras/diagnóstico , Doenças das Cabras/virologia , Cabras/virologia , Lentivirus/classificação , Lentivirus/isolamento & purificação , Soroconversão , Testes Sorológicos/métodos , Ovinos/virologia , Doenças dos Ovinos/diagnóstico , Doenças dos Ovinos/virologia , Virologia/métodos , Vírus Visna-Maedi/genética , Vírus Visna-Maedi/imunologiaRESUMO
Caprine arthritis encephalitis virus (CAEV) is a monocyte/macrophage-tropic lentivirus that primarily infects goats resulting in a well-recognized set of chronic inflammatory syndromes focused on the joint synovium, tissues of the central nervous system, pulmonary interstitium and mammary gland. Clinically affected animals generally manifest with one or more of these classic CAEV-associated tissue lesions; however, CAEV-associated renal inflammation in goats has not been reported in the peer-reviewed literature. Here we describe six goats with chronic, multisystemic CAEV infections in conjunction with CAEV-associated renal lesions. One of the animals had CAEV antigen-associated thrombotic arteritis resulting in infarction of both the kidney and heart. These goats had microscopic evidence of inflammatory renal injury (interstitial nephritis) with detectable renal immunolabeling for CAEV antigen in three of six animals and amplifiable proviral sequences consistent with CAEV in all six animals. Cardiac lesions (vascular, myocardial or endocardial) were also identified in four of six animals. Within the viral promoter (U3) region, known transcription factor binding sites (TFBSs) were generally conserved, although one viral isolate had a duplication of the U3 A region encoding a second gamma-activated site (GAS). Despite the TFBS conservation, the isolates demonstrated a degree of phylogenetic diversity. At present, the clinical consequence of CAEV-associated renal injury is not clear.
Assuntos
Vírus da Artrite-Encefalite Caprina/patogenicidade , Rim/patologia , Rim/virologia , Infecções por Lentivirus/complicações , Infecções por Lentivirus/veterinária , Nefrite Intersticial/veterinária , Nefrite Intersticial/virologia , Animais , Vírus da Artrite-Encefalite Caprina/classificação , Vírus da Artrite-Encefalite Caprina/genética , Doenças das Cabras/sangue , Doenças das Cabras/virologia , Cabras/virologia , Inflamação/virologia , Rim/imunologia , Infecções por Lentivirus/sangue , Filogenia , Regiões Promotoras Genéticas , Provírus/genéticaRESUMO
Objetivou-se avaliar um programa de controle da artrite encefalite caprina (AEC), por meio de testes diagnósticos sensíveis, separação de mãe e cria após o parto e medidas de manejo, com o intuito de formar rebanho livre do vírus. Utilizou-se um total de 47 cabritos da raça Saanen, mantidos isoladamente até o resultado dos primeiros testes de reação em cadeia de polimerase nested (PCR nested) e Western Blotting (WB), com base na coleta de sangue no momento do nascimento (M0). No PCR nested, quatro animais foram positivos, no M0, e foram eutanasiados. Posteriormente, os demais 43 cabritos foram submetidos à coleta de sangue aos 60 (M60) e 270 (M270) dias de vida para realização de novos testes de WB e PCR nested, que não detectaram animais positivos. Pode-se afirmar que a metodologia adotada neste estudo foi efetiva no controle da doença, nas fases de aleitamento e pós-aleitamento, e que a combinação do sistema de manejo, a fim de propiciar diminuição de risco de transmissão horizontal, com técnicas de diagnóstico mais apuradas, como o WB e a PCR nested, é relevante para elaboração de plano estratégico de controle da enfermidade.(AU)
We aimed to evaluate a program to control Caprine Arthritis Encephalitis (CAE), using diagnostic tests, separation of the mother and postpartum and other management measures, in order to form a free flock of the virus. We used a total of 47 Saanengoats in isolation until the results of the first nested Polymerase Chain Reaction (nested PCR) and Western Blotting (WB) tests, based on blood collection at the time of birth (M0). In the nested PCR, 4 animals were positive, at M0, and were eliminated. Later, the other 43goats were submitted to blood collection at 60 (M60) and 270 (M270) days of life to perform new tests of WB and nested PCR, which did not detect positive animals. We can affirm that the methodology adopted in this study was effective in the control of the disease, in the phase of breastfeeding and post-breastfeeding, and that the combination of the management system, which allows a reduction of risk of horizontal transmission, with more accurate diagnostic techniques, such as WB and nested PCR, is relevant for the elaboration of a strategic plan for the disease control.(AU)
Assuntos
Animais , Cabras/virologia , Infecções por Lentivirus/prevenção & controle , Vírus da Artrite-Encefalite Caprina/isolamento & purificação , Reação em Cadeia da Polimerase/veterináriaRESUMO
Aluminum (Al)-based salts are widely used adjuvants in ruminants and other species to strengthen the immune response elicited against vaccine antigen(s). However, they can lead to the formation of long-lasting granulomas composed of abundant activated macrophages. Small ruminant lentiviruses (SRLV) are widely distributed macrophage-tropic retroviruses that cause persistent infections in sheep and goats. Infected monocytes/macrophages and dendritic cells establish an inflammatory microenvironment that eventually leads to clinical manifestations. The aim of this work was to study the effect of Al-induced granulomas in the replication and pathogenesis of SRLV. Eleven adult, naturally SRLV-infected sheep showing clinical arthritis were distributed in vaccine (n = 6), adjuvant-only (n = 3), and control (n = 2) groups and inoculated with commercial Al-based vaccines, Al hydroxide adjuvant alone, or phosphate-buffered saline, respectively. In vitro studies demonstrated viral replication in Al-induced granulomas in 5 out of 10 sheep. Immunohistochemistry (IHC) evinced granular, intracytoplasmic SRLV presence in macrophages within granulomas. Viral sequences obtained from granulomas, blood monocytes, and other tissues were highly similar in most animals, suggesting virus circulation among body compartments. However, notable differences between isolated strains in granulomas and other tissues in specific animals were also noted. Interestingly, the B2 subtype was the most commonly found SRLV genotype, reaching a wider body distribution than previously described. Recombination events between genotypes B2 and A3 along the gag region were identified in two sheep. Our results indicate that Al-hydroxide-derived granulomas may represent an ideal compartment for SRLV replication, perhaps altering natural SRLV infection by providing a new, suitable target tissue.IMPORTANCE Granulomas are inflammation-derived structures elicited by foreign bodies or certain infections. Aluminum adjuvants included in vaccines induce granulomas in many species. In sheep, these are persistent and consist of activated macrophages. Small ruminant lentiviruses (SRLV), which are macrophage-tropic lentiviruses, cause a chronic wasting disease affecting animal welfare and production. Here, we studied the occurrence of SRLV in postvaccination granulomas retrieved from naturally infected ewes after vaccination or inoculation with aluminum only. SRLV infection was confirmed in granulomas by identification of viral proteins, genomic fragments, and enzymatic activity. The infecting SRLV strain, previously found exclusively in carpal joints, reached the central nervous system, suggesting that occurrence of SRLV in postvaccination granulomas may broaden tissue tropism. SRLV recombination was detected in inoculated animals, a rare event in sheep lentiviruses. Potentially, virus-host interactions within granulomas may modify viral pathogenesis and lead to more widespread infection.
Assuntos
Adjuvantes Imunológicos/efeitos adversos , Hidróxido de Alumínio/efeitos adversos , Vírus da Artrite-Encefalite Caprina/fisiologia , Granuloma/veterinária , Infecções por Lentivirus/veterinária , Doenças dos Ovinos/virologia , Replicação Viral/efeitos dos fármacos , Animais , Vírus da Artrite-Encefalite Caprina/classificação , Vírus da Artrite-Encefalite Caprina/efeitos dos fármacos , Vírus da Artrite-Encefalite Caprina/isolamento & purificação , Genótipo , Granuloma/induzido quimicamente , Granuloma/virologia , Infecções por Lentivirus/virologia , Macrófagos/efeitos dos fármacos , Macrófagos/virologia , Filogenia , Recombinação Genética , Ovinos , Doenças dos Ovinos/induzido quimicamente , Tropismo ViralRESUMO
Caprine arthritis-encephalitis virus (CAEV), a lentivirus, relies on the action of the Rev protein for its replication. The CAEV Rev fulfills its function by allowing the nuclear exportation of partially spliced or unspliced viral mRNAs. In this study, we characterized the nuclear and nucleolar localization signals (NLS and NoLS, respectively) and the nuclear export signal (NES) of the CAEV Rev protein. These signals are key actors in the nucleocytoplasmic shuttling of a lentiviral Rev protein. Several deletion and alanine substitution mutants were generated from a plasmid encoding the CAEV Rev wild-type protein that was fused to the enhanced green fluorescent protein (EGFP). Following cell transfection, images were captured by confocal microscopy and the fluorescence was quantified in the different cell compartments. The results showed that the NLS region is localized between amino acids (aa) 59 to 75, has a monopartite-like structure and is exclusively composed of arginine residues. The NoLS was found to be partially associated with the NLS. Finally, the CAEV Rev protein's NES mapped between aa 89 to 101, with an aa spacing between the hydrophobic residues that was found to be unconventional as compared to that of other retroviral Rev/Rev-like proteins.
Assuntos
Vírus da Artrite-Encefalite Caprina/genética , Núcleo Celular/metabolismo , Produtos do Gene rev/genética , Sinais Direcionadores de Proteínas , Transporte Ativo do Núcleo Celular , Sequência de Aminoácidos , Animais , Vírus da Artrite-Encefalite Caprina/metabolismo , Bovinos , Núcleo Celular/virologia , Produtos do Gene rev/metabolismo , Proteínas de Fluorescência Verde , Células HeLa , Humanos , Macrófagos/virologia , Sinais de Exportação Nuclear , Sinais de Localização Nuclear/metabolismoRESUMO
Since 2007, the Autonomous Province of Bolzano-South Tyrol (Italy) has carried out a compulsory eradication program against caprine arthritis encephalitis virus (CAEV) in goats. A drastic seroprevalence reduction was achieved during the initial phase (2007-2011); however, a tailing phenomenon has been observed during the latest years, hampering the achievement of the final goal. CAEV belongs to a group of lentiviruses, called small ruminant lentiviruses (SRLVs), which are antigenically related and can infect both goats and sheep. We investigated the possible link between the tailing phenomenon in goats and the role of sheep as a virus reservoir by comparing serologic results between multispecies farms (where goats and sheep coexist) and monospecies farms (goats only). Goats on multispecies farms had a higher prevalence and seroconversion rate (even if to a rather moderate extent), higher antibody titers, and a higher probability of conclusive results in the genotyping analysis, with more frequent identification of SRLV genotype A (sheep-related) infections. Sheep can serve as a SRLV reservoir, thus contributing to scattered positive tests in goats, causing the tailing phenomenon.
Assuntos
Vírus da Artrite-Encefalite Caprina/fisiologia , Erradicação de Doenças , Reservatórios de Doenças/veterinária , Doenças das Cabras/prevenção & controle , Infecções por Lentivirus/veterinária , Carneiro Doméstico/virologia , Animais , Doenças das Cabras/virologia , Cabras , Itália , Infecções por Lentivirus/prevenção & controle , Infecções por Lentivirus/virologia , Prevalência , SoroconversãoRESUMO
Caprine arthritis-encephalitis (CAE) is a chronic progressive infectious disease caused by caprine arthritis-encephalitis virus (CAEV) that seriously threatens the goat industry. Chronic infection and life-long multi-tissue inflammation are the typical features of the disease. Innate antiviral immunity is essential for the host defense system that rapidly recognizes and eliminates invading viruses. Interferon ß (IFN-ß) is important for innate immunity and regulates immunity against a broad spectrum of viruses. To investigate the details of the IFN-ß response to CAEV infection, the effects of six viral proteins and the molecular mechanisms by which they affect IFN-ß production were analyzed. Overexpression of DU and Vif promote virus proliferation and inhibit the production of IFN-ß. qRT-PCR and luciferase reporter assays showed that overexpression of Vif inhibits the expression of luciferase under the control of the ISRE, NF-κB or IFN-ß promoter but does not affect the expression of IFN-ß activated by IRF3, indicating that Vif negatively regulates IFN-ß production by affecting upstream signal transduction of IRF3. Amino acids 149-164 of Vif were found to be necessary for the inhibitory effect of IFN-ß production. Our results indicate that CAEV evades surveillance and clearance by intracellular innate immunity by downregulating IFN-ß production.
Assuntos
Vírus da Artrite-Encefalite Caprina/imunologia , Produtos do Gene vif/imunologia , Doenças das Cabras/imunologia , Interferon beta/imunologia , Infecções por Lentivirus/veterinária , Animais , Vírus da Artrite-Encefalite Caprina/genética , Produtos do Gene vif/genética , Doenças das Cabras/genética , Doenças das Cabras/virologia , Cabras , Interações Hospedeiro-Patógeno , Imunidade Inata , Interferon beta/genética , Infecções por Lentivirus/genética , Infecções por Lentivirus/imunologia , Infecções por Lentivirus/virologia , NF-kappa B/genética , NF-kappa B/imunologiaRESUMO
Caprine arthritis encephalitis (CAE) is a chronic disease caused by a retrovirus from the Lentivirus genus. No effective vaccines or treatments exist, and therefore genetic selection for CAE resistance might be a feasible alternative. To our best knowledge, no other studies have investigated the genetic architecture of CAE resistance in dairy goats. In this context, this study was designed to estimate genetic parameters for CAE infection in Alpine and Saanen goats using a Bayesian threshold model. A total of 542 adult goats (and >3-generation pedigree), which were group-housed in a population with high CAE prevalence, were tested based on a serological infection assessment test (negative = 1 or positive = 2) and used for this study. Genetic parameters were estimated using the BLUPF90 family programs. There was considerable genetic variability for CAE resistance, and pedigree-based heritability was significantly different from zero (0.026 < heritability < 0.128). Our findings indicate that the prevalence of CAE in goat herds can be reduced or eliminated through direct genetic selection for CAE resistance in addition to proper management strategies.
Assuntos
Vírus da Artrite-Encefalite Caprina , Predisposição Genética para Doença , Doenças das Cabras/virologia , Infecções por Lentivirus/veterinária , Animais , Teorema de Bayes , Doenças das Cabras/epidemiologia , Cabras , Infecções por Lentivirus/genética , Infecções por Lentivirus/virologiaRESUMO
Small ruminant lentiviruses (SRLV) are widespread amongst domesticated sheep and goats worldwide. Infection of wild ruminants in close contact with affected domesticated small ruminants has been proposed as an actor in SRLV epidemiology, but studies are limited. The aim of this study was to estimate the apparent (AP) and estimated prevalence (EP) of exposure to SRLV infection in wild ruminants from Poland. Samples originating from 198 free-living cervids comprising 142 European red deer and 56 roe deer were serologically tested using a multi-epitope recombinant antigen ELISA representing subtypes A1, A13, B1, and B2 of SRLV and a commercial ELISA test. The estimated prevalence of SRLV infection was estimated using the Bayesian approach with models that adjusted for the misclassification of animals because of a small population and lack of sampling method, the imperfect performance of the ELISAs and because sera of different species were tested. The calculated estimated prevalence ranged from 5.3 % (95 % CI 0.3, 12.5) to 24.6 % (95 % CI 3.3, 38.5) for the ELISA with multi-epitope antigens while estimated prevalence using the commercial ELISA was 2.5 % (95 % CI 0.2, 6.6). These results may suggest the existence of a new SRLV reservoir in Poland and highlight the importance of surveilling and controlling SRLV infection in domestic and wild ruminants sharing pasture areas.
Assuntos
Anticorpos Antivirais/sangue , Vírus da Artrite-Encefalite Caprina/fisiologia , Cervos , Infecções por Lentivirus/veterinária , Animais , Feminino , Infecções por Lentivirus/sangue , Infecções por Lentivirus/epidemiologia , Infecções por Lentivirus/virologia , Masculino , Polônia/epidemiologia , Prevalência , Estudos SoroepidemiológicosRESUMO
Contagious agalactia is a disease caused by Mycoplasma agalactiae that leads to a reduction or complete stop of milk production. Caprine arthritis encephalitis (CAE) is an infectious disease caused by a lentivirus of the Retroviridae family, member of the small ruminant lentivirus (SRLV) group. Although these diseases are caused by distinct pathogens, the clinical presentation is similar. Hence, this study aimed to perform a serological investigation, as well as to assess correlation between both diseases and risk factors associated in two mesoregions of Rio Grande do Norte, Brazil. Enzyme-linked immunosorbent assay (ELISA) was used for contagious agalactia and western blot for CAE. A total of 538 serum samples were used in this study that were collected from goats and sorted from a blood bank of the Brazilian Agricultural Research Corporation. Seroprevalence of M. agalactiae in flocks from Rio Grande do Norte was 7.8% (42/538). In both regions that were investigated, 25.9% (14/54) of farms had positive animals. CAE results revealed that 3.9% (21/538) of animals and 42.6% (23/54) of farms had this disease. Concerning risk factors, only sex and animal category presented significant relevance (P < 0.05) for contagious agalactia, in which females presented higher frequency of seropositive individuals (10.1%; 39/387). In the animal category, 4.3% (14/326) and 11.1% (36/323) of female breeders were positive for CAE and contagious agalactia, respectively, and significance was identified only in the latter (P < 0.05). In conclusion, there was no correlation between the investigated diseases, considering that no animal demonstrated antibodies for both pathogens.
Assuntos
Vírus da Artrite-Encefalite Caprina/isolamento & purificação , Doenças das Cabras/epidemiologia , Infecções por Lentivirus/veterinária , Infecções por Mycoplasma/veterinária , Mycoplasma agalactiae/isolamento & purificação , Animais , Brasil/epidemiologia , Coinfecção , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Doenças das Cabras/microbiologia , Cabras , Infecções por Lentivirus/complicações , Infecções por Lentivirus/epidemiologia , Masculino , Infecções por Mycoplasma/complicações , Infecções por Mycoplasma/epidemiologia , Fatores de Risco , Estudos SoroepidemiológicosRESUMO
Visna/Maedi is a disease of sheep caused by small ruminant lentivirus (SRLV) infection that is widespread throughout the world and that has been recognized to be present in the Basque Country (Spain) since the early 1980's. Nearly seven decades of studies have improved the knowledge on its clinical signs and epidemiology. However, its slow progressive nature, subclinical most of the time, makes difficult to assess its real impact on productive traits, a question of critical importance to balance out the economic costs it causes and the benefits of designing and deploying an eradication program. Development of a dairy breeding program since the 90 s in the local Latxa sheep population has provided data on milk productivity in several flocks where SRLV infection prevalence has been continuously monitored. This study analyses retrospectively the association between SRLV prevalence and production variables during ten yearly lactations in three Latxa dairy flocks with medium-high SRLV seroprevalence. Our results indicate that average standard lactation of seropositive sheep was 6.7 % lower than controls. The largest differences (p < 0.001) were observed at the ewe lifetime peak of production between second and fourth lactations. Lifelong milk and lamb production data indicated even a higher impact, with costs rising up to nearly 50 /ewe/year. This substantial production decrease associated with subclinical SRLV infection in Latxa dairy sheep supports the benefit of establishing a SRLV control program. A rough cost-benefit analysis indicated that even in a medium-yielding breed, testing expenses would be largely covered by milk production improvement.
Assuntos
Vírus da Artrite-Encefalite Caprina/fisiologia , Indústria de Laticínios/economia , Infecções por Lentivirus/veterinária , Leite/economia , Doenças dos Ovinos/economia , Animais , Infecções por Lentivirus/economia , Infecções por Lentivirus/epidemiologia , Infecções por Lentivirus/virologia , Modelos Lineares , Prevalência , Estudos Retrospectivos , Estudos Soroepidemiológicos , Ovinos , Doenças dos Ovinos/epidemiologia , Doenças dos Ovinos/virologia , Carneiro Doméstico , Espanha/epidemiologiaRESUMO
BACKGROUND: The small ruminant lentiviruses (SRLVs) are a heterogeneous group of viruses that includes caprine arthritis encephalitis virus (CAEV) and Maedi-Visna virus (MVV). SRLVs affect the production and welfare of sheep and goats worldwide. There is currently no effective treatment. Their high mutation rate precludes vaccine development, making innovative control measures necessary. A variant of the chemokine (C-C motif) receptor 5 (CCR5) gene is reportedly involved in resistance to human immunodeficiency (HIV) infection in humans and to SRLV in sheep. The aim of this study was to analyse the genetic structure and variability of the CCR5 gene in goats and to carry out a cross-sectional study to investigate the role of CCR5 genetic variants in controlling susceptibility/resistance to CAEV. RESULTS: The variant g.1059 T located in the promoter region revealed an interesting association with high proviral loads (a 2.8-fold increased risk). A possible explanation could be an alteration of the transcriptional level. Overexpression of the CCR5 receptor on the cell surface may increase virus internalization and proviral load as a consequence. CONCLUSIONS: Our findings could be advantageously used to reduce the susceptibility of goat herds to CAEV by negatively selecting animals carrying the g.1059 T mutation. Eliminating animals predisposed to high proviral loads could also limit the development of clinical signs and the spread of the virus, since these animals are also highly efficient in shedding the virus.