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2.
BMC Vet Res ; 17(1): 168, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33858420

RESUMO

BACKGROUND: Equine infectious anemia (EIA) is a viral disease, caused by the Equine Infectious Anemia virus (EIAV) belonging to the Retroviridae family, genus Lentivirus. Horses (or equids) infected with EIAV are lifelong carriers and they remain contagious for other horses even in the absence of clinical signs. So far, EIAV infection has been reported among horses in North and South America, France, Germany, Italy, Hungary and Romania, with no publication regarding the presence of EIAV in horses in Serbia. To determine the circulation of EIAV among, approximately, the 5000 horses of the Vojvodina region, northern part of Serbia, 316 serum undergone serological testing for EIA. Then, identification and full genome sequencing using next generation sequencing was performed from one EIA positive horse. RESULTS: the 316 sera were tested with 3 different commercial agar gel immunodiffusion (AGID) tests and two different commercial enzyme-linked immunosorbent assay (ELISA). With the three AGID kits, 311 (98.4%) among the 316 tested sera were negative and only five (1.6%) sera were positive for EIA. Some discrepancies were seen for the two ELISA kits tested since one exhibited the same results as AGID test and the second gave 295 sera with negative results, five with a positive result and 16 with doubtful outcome. Phylogenetic analysis performed using the full genome sequence showed that EIAV characterized from a horse in Serbia is different from those identify so fare around the world and form a distinct and separate group together with another EIAV strain. CONCLUSIONS: This study demonstrate for the first time that EIAV is circulating at a low level in the horse population from the Northern part of Serbia. Interestingly, phylogenetic data indicates that this EIAV from the western Balkan region of Europe belongs to a new cluster.


Assuntos
Anemia Infecciosa Equina/epidemiologia , Vírus da Anemia Infecciosa Equina/genética , Vírus da Anemia Infecciosa Equina/isolamento & purificação , Animais , Ensaio de Imunoadsorção Enzimática/veterinária , Anemia Infecciosa Equina/virologia , Genoma Viral , Cavalos , Vírus da Anemia Infecciosa Equina/classificação , Filogenia , Sérvia/epidemiologia , Estudos Soroepidemiológicos
3.
J Vet Diagn Invest ; 33(4): 758-761, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33797316

RESUMO

Equine infectious anemia (EIA) is a highly infectious disease in members of the Equidae family, caused by equine infectious anemia virus (EIAV). The disease severity ranges from subclinical to acute or chronic, and causes significant economic losses in the equine industry worldwide. Serologic tests for detection of EIAV infection have some concerns given the prolonged seroconversion time. Therefore, molecular methods are needed to improve surveillance programs for this disease. We attempted detection of EIAV in 6 clinical and 42 non-clinical horses in Nuevo Leon State, Mexico, using the agar gel immunodiffusion (AGID) test for antibody detection, and nested and hemi-nested PCR for detection of proviral DNA. We found that 6 of 6, 5 of 6, and 6 of 6 clinical horses were positive by AGID, nested PCR, and hemi-nested PCR, respectively, whereas 0 of 42, 1 of 42, and 9 of 42 non-clinical horses were positive by these tests, respectively. BLAST analysis of the 203-bp 5'-LTR/tat segment of PCR product revealed 83-93% identity with EIAV isolates in GenBank and reference strains from other countries. By phylogenetic analysis, our Mexican samples were grouped in a different clade than other sequences reported worldwide, indicating that the LRT/tat region represents an important target for the detection of non-clinical horses.


Assuntos
Anemia Infecciosa Equina/diagnóstico , Vírus da Anemia Infecciosa Equina/isolamento & purificação , Animais , Anemia Infecciosa Equina/epidemiologia , Anemia Infecciosa Equina/virologia , Feminino , Cavalos , Masculino , México/epidemiologia , Filogenia , Reação em Cadeia da Polimerase/veterinária , Prevalência , Testes Sorológicos/veterinária
4.
J Equine Vet Sci ; 98: 103372, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33663722

RESUMO

Equine infectious anemia is a worldwide distributed disease that affects the Equide family. Commercial effective vaccine is not available, for that reason control of the disease depends on diagnostic tools. To improve the efficiency of the diagnostic program in Cuba, LABIOFAM Group, developed an indirect enzyme-linked immunosorbent assay (ELISA), ELISA kit, to complement the diagnostic system that currently uses the agar gel immunodiffusion (AGID) kit. The ELISA AIE-LAB Kit was evaluated in a Mexican context, compared with the gold standard test Agar gel immunodiffusion, AGID AIE-LABIOFAM, and commercial AGID kit. The analytical sensitivity was determined using serial dilutions twofold of the positive control serum to establish the range of detected antibodies in relation to the cutoff value of the plate (OD 0.300). A precision study was carried out to evaluate repeatability, intermediate precision, and reproducibility by estimating the standard deviation and coefficient of variation. The precision results were satisfactory and the values of the coefficient of variation were considered adequate to guarantee an excellent consistency of the ELISA AIE-LAB. The diagnostic performance of the ELISA AIE-LAB involved the evaluation of specificity, sensitivity, and concordance in comparison with both AGID tests. The diagnostic sensitivity was 100% and the specificity 97.6%, with a very good degree of concordance (Kappa = 0.9). The results suggest that the ELISA AIE-LAB test could be used in Mexico as a diagnostic system for the detection of specific antibodies against the equine infectious anemia virus, as per current international norms.


Assuntos
Anemia Infecciosa Equina , Doenças dos Cavalos , Vírus da Anemia Infecciosa Equina , Animais , Anticorpos Antivirais , Cuba , Ensaio de Imunoadsorção Enzimática/veterinária , Anemia Infecciosa Equina/diagnóstico , Cavalos , México , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
5.
Prev Vet Med ; 190: 105319, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33713963

RESUMO

Equine infectious anemia virus (EIAV) is a transboundary disease affecting a large number of equines worldwide. In this study, we assessed the transmission risk of EIAV in Rio Grande do Sul, Brazil. Serum samples from 1010 animals from 341 farms were initially analyzed using agar gel immunodiffusion to detect viral antibodies, and no antibody-positive animals were found. A risk assessment stochastic model was applied to generate the expected number of potential infections per month and to estimate the time to new infections. Our results estimated 6.5 months as the interval for new infections in the worst-case scenario. Among the variables evaluated, the number of transported animals and the test sensitivity influenced the model the most. These results were then used to revisit the impact of EIAV control regulations, which triggered a change in the diagnostic testing required for animal movement, in which the validity of a negative test for EIAV was extended from 60 to 180 days. Finally, revisiting the annual average of infected farms before and after the new regulation, the number of infected farms increased pre-implementation, and then, the number of culled animals increased, which should impact future EIAV incidence in this region. Our results demonstrated the importance of constant reviews of disease control programs and provided quantitative-based knowledge for decision-makers in official veterinary services.


Assuntos
Anemia Infecciosa Equina , Doenças dos Cavalos , Vírus da Anemia Infecciosa Equina , Animais , Anticorpos Antivirais , Brasil/epidemiologia , Anemia Infecciosa Equina/epidemiologia , Doenças dos Cavalos/epidemiologia , Doenças dos Cavalos/virologia , Cavalos , Medição de Risco , Transportes
6.
J Virol Methods ; 291: 114101, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33609629

RESUMO

Equine Infectious Anemia is a transmissible viral disease present worldwide, caused by an RNA virus. Viral transmission is mainly mechanical through blood or its products most frequently by blood-sucking arthropods and iatrogenesis as well. OIE recommends Coggins Test as the diagnostic method of choice. Some ELISA tests detect antibodies earlier than the Coggins test, but may produce false-positive results. Currently, new techniques for EIA diagnosis are being developed, such as fluorescence polarization assay which is a simple method for measuring antigen-antibody interaction. The aim of this study was to assess cELISA and Fluorescence Polarization Assay performance for the serological diagnosis of EIA by comparing their results with those of the Coggins test. Tests were performed on 91 workhorses from an endemic zone in the northeast region of Argentina. From the total samples analyzed, 42 tested negative and 49 tested positive in the Coggins test. Same results were obtained using FPA. Using the cELISA, 41 negative results and 50 positive results were obtained. The Receiver Operating Characteristic analysis showed that FPA performance was excellent. Therefore FPA is proposed as an outstanding EIA diagnostic test to be validated in the near future by its simplicity, speed, and objective interpretation of results.


Assuntos
Anemia Infecciosa Equina , Vírus da Anemia Infecciosa Equina , Animais , Anticorpos Antivirais , Argentina/epidemiologia , Ensaio de Imunoadsorção Enzimática , Anemia Infecciosa Equina/diagnóstico , Anemia Infecciosa Equina/epidemiologia , Cavalos , Sensibilidade e Especificidade
7.
Emerg Microbes Infect ; 9(1): 1309-1320, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32525460

RESUMO

Lentiviruses harbour high genetic variability for efficient evasion from host immunity. An attenuated equine infectious anaemia (EIA) vaccine was developed decades ago in China and presented remarkably robust protection against EIA. The vaccine was recently proven to have high genomic diversity, particular in env. However, how and to what extent the high env diversity relates to immune protection remains unclear. In this study, we compared immune protections and responses of three groups of horses stimulated by the high-diversity vaccine EIAV_HD, a single molecular clone of the vaccine EIAV_LD with low env diversity, as well as a constructed vaccine strain EIAV_MD with moderate env diversity. The disparity of virus-host interactions between three env diversity-varied groups (5 horses in each group) was evaluated using clinical manifestation, pathological scores, and env-specific antibody. We found the highest titres of env antibodies (Abs) or neutralizing Abs (nAbs) in the EIAV_HD group, followed by the EIAV_MD group, and the lowest titres in the EIAV_LD group (P<0.05). The occurrence of disease/death was different between EIAV_HD group (1/0), EIAV_MD (2/2), and EIAV_LD group (4/2). A similar env diversity-related linear relationship was observed in the clinical manifestations and pathological changes. This diversity-dependent disparity in changes between the three groups was more distinct after immunosuppression, suggesting that env diversity plays an important role in protection under low host immunocompetence. In summary, inoculation with vaccines with higher genetic diversity could present broader and more efficient protection. Our findings strongly suggest that an abundance of Env antigens are required for efficient protection against lentiviruses.


Assuntos
Anemia Infecciosa Equina/prevenção & controle , Produtos do Gene env/imunologia , Vírus da Anemia Infecciosa Equina/fisiologia , Polimorfismo de Nucleotídeo Único , Vacinas Virais/administração & dosagem , Animais , Anticorpos Neutralizantes/metabolismo , Anticorpos Antivirais/metabolismo , Anemia Infecciosa Equina/imunologia , Produtos do Gene env/genética , Sequenciamento de Nucleotídeos em Larga Escala , Cavalos , Vacinas Atenuadas , Vacinas Virais/imunologia , Vacinas Virais/farmacologia , Replicação Viral/efeitos dos fármacos
8.
Virus Genes ; 56(3): 339-346, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32239368

RESUMO

Increasing evidence suggests that DNA methylation has key roles in the replication of retroviruses, including lentiviruses, and pathogenesis of diseases. However, the precise characteristics of CpG islands are not known for many retroviruses. In this study, we compared the distribution of CpG islands among strains of equine infectious anemia virus (EIAV), a lentivirus in the family Retroviridae and a model for HIV research. We identified CpG islands in 32 full-length EIAV genomic sequences obtained from the GenBank database using MethPrimer. Only one CpG island, from 100 to 120 bp, was identified in the genomes of EIAV strains DV10, DLV3-A, and DLV5-10 from China, V26 and V70 from Japan, and IRE H3, IRE F2, IRE F3, and IRE F4 from Ireland. Importantly, the CpG island was located within the Rev gene, which is required for the expression of viral cis-acting elements and the production of new virions. These results suggest that the distribution, length, and genetic properties of CpG islands differ among EIAV strains. Future research should focus on the biological significance of this CpG island within rev to improve our understanding of the precise roles of CpG islands in epigenetic regulation in the species.


Assuntos
Ilhas de CpG , Metilação de DNA , Epigênese Genética , Anemia Infecciosa Equina/virologia , Vírus da Anemia Infecciosa Equina/genética , Animais , Genes Virais , Genoma Viral , Genômica/métodos , Cavalos , Mutação , Filogenia , Análise de Sequência de DNA
9.
Arch Virol ; 165(6): 1333-1342, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32266552

RESUMO

Equine infectious anemia (EIA), a disease caused by equine infectious anemia virus (EIAV), is considered an obstacle to the development of the horse industry. There is no treatment or vaccine available for EIA, and its pathogenesis, as well as the immune response against the virus, is not fully understood. Therefore, an immunohistochemistry assay was developed for the detection of viral antigens in tissues of equids naturally infected with EIAV. Sections of organs of six equids from Apodi-RN, Brazil, that tested positive for EIA by serological tests (ELISA and AGID) were fixed in 10% formalin solution and embedded in paraffin. Immunohistochemistry was performed using a polyclonal anti-EIAV antibody. EIAV antigens were observed in red spleen pulp cells and hepatic sinusoids, as well as bronchiolar and alveolar epithelial cells of the lungs and proximal and distal tubules of the kidneys. The presence of EIAV in the spleen and liver was expected due to viral tropism by macrophages, which are abundantly present in these organs. However, EIAV was also found in lung and kidney epithelial cells, indicating that the virus infects cell types other than macrophages. In conclusion, the immunohistochemical assay standardized in this study was able to detect EIAV antigens in spleen, liver, kidney and lung cells from naturally infected EIAV equids. Immunostaining observed in the spleen confirms viral tropism by mononuclear phagocytes; however, the presence of EIAV in lung and kidney epithelial cells indicates that virus may be eliminated in urine and/or oronasal secretions, suggesting new routes for viral excretion.


Assuntos
Anemia Infecciosa Equina/virologia , Vírus da Anemia Infecciosa Equina/isolamento & purificação , Animais , Antígenos Virais/análise , Brasil , DNA Viral/genética , Células Epiteliais/patologia , Células Epiteliais/virologia , Anemia Infecciosa Equina/imunologia , Anemia Infecciosa Equina/patologia , Cavalos/virologia , Vírus da Anemia Infecciosa Equina/classificação , Rim/patologia , Rim/virologia , Leucócitos Mononucleares/virologia , Fígado/patologia , Fígado/virologia , Pulmão/patologia , Pulmão/virologia , Reação em Cadeia da Polimerase , Testes Sorológicos , Baço/patologia , Baço/virologia
10.
Viruses ; 12(2)2020 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-32059508

RESUMO

Equine infectious anemia virus (EIAV) is a persistent lentivirus that causes equine infectious anemia (EIA). In Brazil, EIAV is endemic in the Pantanal region, and euthanasia is not mandatory in this area. All of the complete genomic sequences from field viruses are from North America, Asia, and Europe, and only proviral genomic sequences are available. Sequences from Brazilian EIAV are currently available only for gag and LTR regions. Thus, the present study aimed for the first time to sequence the entire EIAV genomic RNA in naturally infected horses from an endemic area in Brazil. RNA in plasma from naturally infected horses was used for next-generation sequencing (NGS), and gaps were filled using Sanger sequencing methodology. Complete viral genomes of EIAV from two horses were obtained and annotated (Access Number: MN560970 and MN560971). Putative genes were analyzed and compared with previously described genes, showing conservation in gag and pol genes and high variations in LTR and env sequences. Amino acid changes were identified in the p26 protein, one of the most common targets used for diagnosis, and p26 molecular modelling showed surface amino acid alterations in some epitopes. Brazilian genome sequences presented 88.6% nucleotide identity with one another and 75.8 to 77.3% with main field strains, such as EIAV Liaoning, Wyoming, Ireland, and Italy isolates. Furthermore, phylogenetic analysis suggested that this Brazilian strain comprises a separate monophyletic group. These results may help to better characterize EIAV and to overcome the challenges of diagnosing and controlling EIA in endemic regions.


Assuntos
Anemia Infecciosa Equina/virologia , Variação Genética , Genoma Viral , Vírus da Anemia Infecciosa Equina/genética , Animais , Brasil/epidemiologia , Doenças Endêmicas/veterinária , Anemia Infecciosa Equina/epidemiologia , Genômica , Sequenciamento de Nucleotídeos em Larga Escala , Cavalos/virologia , Vírus da Anemia Infecciosa Equina/classificação , Filogenia , RNA Viral/sangue
11.
J Equine Vet Sci ; 85: 102852, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31952638

RESUMO

Although the equine lentivirus (equine infectious anemia virus [EIAV]) poses a major threat to equid populations throughout most regions of the world, detailed knowledge concerning its molecular epidemiology is still in its infancy. Such information is important because the few studies conducted to date suggest there is extensive genetic variation between viral isolates that if confirmed has significant implications for future vaccine design and development of newer diagnostic procedures. Here, we avoid potential assembly artifacts inherent in composite sequencing techniques by using long-range PCR in conjunction with next-generation sequencing for the rapid molecular characterization of all major open reading frames (ORFs) and known transcription factor binding motifs within the long terminal repeats (LTRs) of four North American EIAV isolates from Pennsylvania (EIAVPA), Tennessee (EIAVTN), North Carolina (EIAVNC), and Florida (EIAVFL). These were compared with complete published EIAV field strain genomic sequences from Asia (EIAVLIA, EIAVMIY), Europe (EIAVIRE), and North America (EIAVWY) plus EIAVUK a laboratory variant of EIAVWY. Phylogenetic analysis using the long-range PCR products suggested all the New World EIAV isolates comprised a single monophyletic group associated with EIAVIRE. This is distinct from the Asian isolates and so consistent with known historical details concerning the reintroduction of equids into North America by European settlers. Nonetheless nucleotide sequence identity for example between EIAVPA and EIAVTN, EIAVNC, EIAVFL, EIAVWY, EIAVUK plus EIAVIRE was limited to 84.6%, 81.0%, 82.1%, 80.4%, 80.1%, and 77.6%, respectively, with some of these values being not too dissimilar to those between EIAVPA and EIAVLIA or EIAVMIY at 78.0% and 75.4%, respectively. Overall, these results suggest substantial genetic diversity exists even within North American EIAV isolates. Comparative alignment of predicted amino acid sequences from all strains provides increased understanding concerning the extent of permitted substitutions in each viral ORF and known transcriptional LTR control elements.


Assuntos
Anemia Infecciosa Equina , Doenças dos Cavalos , Vírus da Anemia Infecciosa Equina/genética , Animais , Ásia , Elementos Facilitadores Genéticos , Europa (Continente) , Florida , Cavalos , América do Norte , North Carolina , Fases de Leitura Aberta , Pennsylvania , Filogenia , Tennessee , Estados Unidos
12.
PLoS Pathog ; 16(1): e1008277, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31986188

RESUMO

Retrovirus assembly is driven by the multidomain structural protein Gag. Interactions between the capsid domains (CA) of Gag result in Gag multimerization, leading to an immature virus particle that is formed by a protein lattice based on dimeric, trimeric, and hexameric protein contacts. Among retroviruses the inter- and intra-hexamer contacts differ, especially in the N-terminal sub-domain of CA (CANTD). For HIV-1 the cellular molecule inositol hexakisphosphate (IP6) interacts with and stabilizes the immature hexamer, and is required for production of infectious virus particles. We have used in vitro assembly, cryo-electron tomography and subtomogram averaging, atomistic molecular dynamics simulations and mutational analyses to study the HIV-related lentivirus equine infectious anemia virus (EIAV). In particular, we sought to understand the structural conservation of the immature lentivirus lattice and the role of IP6 in EIAV assembly. Similar to HIV-1, IP6 strongly promoted in vitro assembly of EIAV Gag proteins into virus-like particles (VLPs), which took three morphologically highly distinct forms: narrow tubes, wide tubes, and spheres. Structural characterization of these VLPs to sub-4Å resolution unexpectedly showed that all three morphologies are based on an immature lattice with preserved key structural components, highlighting the structural versatility of CA to form immature assemblies. A direct comparison between EIAV and HIV revealed that both lentiviruses maintain similar immature interfaces, which are established by both conserved and non-conserved residues. In both EIAV and HIV-1, IP6 regulates immature assembly via conserved lysine residues within the CACTD and SP. Lastly, we demonstrate that IP6 stimulates in vitro assembly of immature particles of several other retroviruses in the lentivirus genus, suggesting a conserved role for IP6 in lentiviral assembly.


Assuntos
Anemia Infecciosa Equina/metabolismo , Produtos do Gene gag/química , Produtos do Gene gag/metabolismo , Vírus da Anemia Infecciosa Equina/fisiologia , Ácido Fítico/metabolismo , Vírion/fisiologia , Sequência de Aminoácidos , Animais , Tomografia com Microscopia Eletrônica , Anemia Infecciosa Equina/virologia , Produtos do Gene gag/genética , Infecções por HIV/metabolismo , Infecções por HIV/virologia , HIV-1/genética , HIV-1/fisiologia , HIV-1/ultraestrutura , Cavalos , Interações Hospedeiro-Patógeno , Vírus da Anemia Infecciosa Equina/química , Vírus da Anemia Infecciosa Equina/genética , Vírus da Anemia Infecciosa Equina/ultraestrutura , Alinhamento de Sequência , Vírion/genética , Vírion/ultraestrutura , Montagem de Vírus , Produtos do Gene gag do Vírus da Imunodeficiência Humana/química , Produtos do Gene gag do Vírus da Imunodeficiência Humana/genética , Produtos do Gene gag do Vírus da Imunodeficiência Humana/metabolismo
13.
Schweiz Arch Tierheilkd ; 161(11): 725-738, 2019 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-31685446

RESUMO

INTRODUCTION: Equine infectious anaemia (EIA) is a sporadic viral disease in many countries. Every single case has, however, a dramatic impact: infected animals have to be put down, and quarantine restrictions on horse movements lasting three months lead to substantial economic losses. In Switzerland, the mandatory notification was introduced in 1994 in order to facilitate international traffic. A year later, the "new" Ordinance on epizootics of 1995 classified EIA as a "disease to be eradicated". An infected polo horse in the canton of Argovia in summer 2017 thus represented Switzerland's first official case. It served as a starting point to review the legal frameworks of the EU and Switzerland. Recent publications suggest that there might be some potential to optimize the current diagnostic protocols. EIA is transmitted by virus-containing blood and blood products. Introductions in previously disease-free regions are mostly due to human activities, while blood feeding insects as horse flies or other biting flies act as mechanical vectors only locally within some 100 meters. As before, the new EU Regulations governing animal health do not prescribe national monitoring and control plans, allowing member states to shape them according to their particular situation. However, they have to ensure that equids intended for intracommunity movements comply with specific guarantees. In this context, a fine-tuning of current international standards seems conceivable. Mandatory testing preceding each movement would not be a proportionate option even for the future. Regardless their final wording, it would be a great step for all the actors involved in animal traffic if it were possible to adopt rules that are accepted and uniformly implemented by all competent authorities at national, regional and local level. However, the official system will never be able to guarantee absolute safety. Since there are neither effective vaccines nor treatment protocols, it is crucial that all owners, stablehands, veterinarians, associations, and organizers of horse contests are aware of the disease risks, minimizing them as far as possible by adequate biosecurity measures.


Assuntos
Anemia Infecciosa Equina/prevenção & controle , Animais , Anemia Infecciosa Equina/patologia , Anemia Infecciosa Equina/transmissão , Cavalos , Suíça , Transportes
14.
Can Vet J ; 60(11): 1199-1206, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31692681

RESUMO

This retrospective study describes the detection of equine infectious anemia (EIA) during Canadian Food Inspection Agency (CFIA) disease investigations in Canada, examines aspects of importance for disease control, and evaluates potential animal-level risk factors for EIA in high-risk horses. Based on review of all EIA-positive samples and all samples collected during disease investigations (N = 4553) over a 4-year period (2009 to 2012), 409 EIA cases were detected. Horse owners with EIA cases owned between 1 and 60 affected animals, and 49 horses seroconverted during a disease investigation period. Twenty-nine percent of cases (n = 68) for which this information was available had, or possibly had, clinical signs of EIA. Using a mixed effects logistic regression model, horses in older age groups were at greater odds of having a positive EIA status. The study emphasizes the importance of disease investigation activities when EIA is detected and identifies age as an animal-level risk factor in high-risk horses.


Assuntos
Anemia Infecciosa Equina , Vírus da Anemia Infecciosa Equina , Animais , Canadá , Análise Fatorial , Cavalos , Estudos Retrospectivos , Fatores de Risco
15.
Virology ; 537: 121-129, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31493650

RESUMO

Equine infectious anemia virus (EIAV) is responsible of acute disease episodes characterized by fever, anemia, thrombocytopenia and anorexia in equids. The high mutation rate in EIAV genome limited the number of full genome sequences availability. In the present study, we used the SureSelect target enrichment system with Illumina Next Generation Sequencing to characterize the proviral DNA of Equine Infectious Anemia Virus (EIAV) from asymptomatic horses. This approach allows a direct sequencing of the EIAV whole genome without cloning or amplification steps and we could obtain for the first time the complete genomic DNA sequences of French EIAV strains. We analyzed their phylogenetic relationship and genetic variability by comparison with 17 whole EIAV genome sequences from different parts of the world. The results obtained provide new insights into the molecular detection of EIAV and genetic diversity of European viral strains.


Assuntos
Anemia Infecciosa Equina/virologia , Variação Genética , Sequenciamento de Nucleotídeos em Larga Escala , Vírus da Anemia Infecciosa Equina/classificação , Vírus da Anemia Infecciosa Equina/genética , Animais , Doenças Assintomáticas , França , Cavalos , Vírus da Anemia Infecciosa Equina/isolamento & purificação , Filogenia , Provírus/classificação , Provírus/genética , Provírus/isolamento & purificação , Sequenciamento Completo do Genoma
16.
J Virol ; 93(21)2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31391270

RESUMO

Equine infectious anemia virus (EIAV) is an equine lentivirus similar to HIV-1, targets host immune cells, and causes a life-long infection in horses. The Chinese live EIAV vaccine is attenuated from long-term passaging of a highly virulent strain in vitro The parent pathogenic strain (EIAVDLV34) induces a host inflammatory storm to cause severe pathological injury of animals. However, the vaccine strain (EIAVDLV121) induces a high level of apoptosis to eliminate infected cells. To investigate how these processes are regulated, we performed a comparative proteomics analysis and functional study in equine monocyte-derived macrophages (eMDMs) and found that the divergent mitochondrial protein expression profiles caused by EIAV strains with different virulence led to disparate mitochondrial function, morphology, and metabolism. This in turn promoted the distinct transformation of macrophage inflammatory polarization and intrinsic apoptosis. In EIAVDLV34-infected cells, a high level of glycolysis and increased mitochondrial fragmentation were induced, resulting in the M1-polarized proinflammatory-type transformation of macrophages and the subsequent production of a strong inflammatory response. Following infection with EIAVDLV121, the infected cells were transformed into M2-polarized anti-inflammatory macrophages by inhibition of glycolysis. In this case, a decrease in the mitochondrial membrane potential and impairment of the electron transport chain led to increased levels of apoptosis and reactive oxygen species. These results correlated with viral pathogenicity loss and may help provide an understanding of the key mechanism of lentiviral attenuation.IMPORTANCE Following viral infection, the working pattern and function of the cell can be transformed through the impact on mitochondria. It still unknown how the mitochondrial response changes in cells infected with viruses in the process of virulence attenuation. EIAVDLV121 is the only effective lentiviral vaccine for large-scale use in the world. EIAVDLV34 is the parent pathogenic strain. Unlike EIAVDLV34-induced inflammation storms, EIAVDLV121 can induce high levels of apoptosis. For the first time, we found that, after the mitochondrial protein expression profile is altered, EIAVDLV34-infected cells are transformed into M1-polarized-type macrophages and cause inflammatory injury and that the intrinsic apoptosis pathway is activated in EIAVDLV121-infected cells. These studies shed light on how the mitochondrial protein expression profile changes between cells infected by pathogenic lentivirus strains and cells infected by attenuated lentivirus strains to drive different cellular responses, especially from inflammation to apoptosis.


Assuntos
Anemia Infecciosa Equina/patologia , Vírus da Anemia Infecciosa Equina/patogenicidade , Proteínas Mitocondriais/metabolismo , Animais , Apoptose , Células Cultivadas , Anemia Infecciosa Equina/metabolismo , Anemia Infecciosa Equina/virologia , Glicólise , Cavalos , Inflamação , Macrófagos/metabolismo , Macrófagos/patologia , Macrófagos/virologia , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Proteínas Mitocondriais/genética , Proteômica , Espécies Reativas de Oxigênio , Vacinas Atenuadas , Vacinas Virais , Virulência
18.
Transbound Emerg Dis ; 66(6): 2311-2317, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31267701

RESUMO

Equine infectious anaemia virus (EIAV) is a retrovirus with worldwide distribution which is notifiable to the OIE. Despite its importance to the equine industry, most information regarding its biology have been obtained using only two strains (EIAVWYO and EIAVLIA ) from the USA and China, respectively. Recently full genome sequences from Ireland, Italy and Japan have been published; however, this is still not representative of the number of EIAV outbreaks experienced globally each year. The limited availability of published sequences makes design of a universal EIAV PCR difficult, hence diagnosis is solely reliant on serology. Accordingly, it is important to further investigate the re-emerging cases in other areas of the world. Here, we provide information regarding the outbreaks of EIA in England in 2010 and 2012 including the molecular characterization of strains. Full genome was obtained for two symptomatic cases but could not be resolved for the asymptomatic cases. The two British genomes from 2010 (EIAVDEV ) and 2012 (EIAVCOR ) each represent a new phylogenetic group, each differing genetically from the other available full genome sequences by 21.1%-25.5%. That the majority of new EIAV full genome sequences to be published adds another phylogenetic group indicates that the surface of EIAV global diversity is just being scratched. These data highlight that further work is needed to fully understand EIAV genetic diversity, namely the full genome sequencing of EIAV cases from a variety of locations and time points. This would aid both the use of phylogenetics in parallel with horse tracing as the epidemiological tool of disease tracking and the design of a universally applicable molecular diagnostic method.


Assuntos
Variação Genética , Genoma Viral , Vírus da Anemia Infecciosa Equina/genética , Animais , Surtos de Doenças/veterinária , Inglaterra , Anemia Infecciosa Equina/epidemiologia , Cavalos , Filogenia
19.
Viruses ; 11(4)2019 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-31022927

RESUMO

As the only widely used live lentiviral vaccine, the equine infectious anima virus (EIAV) attenuated vaccine was developed by in vitro passaging of a virulent strain for 121 generations. In our previous study, we observed that the attenuated vaccine was gradually selected under increased environmental pressure at the population level (termed a quasispecies). To further elucidate the potential correlation between viral quasispecies evolution and pathogenesis, a systematic study was performed by sequencing env using several methods. Some key mutations were identified within Env, and we observed that increased percentages of these mutations were accompanied by an increased passage number and attenuated virulence. Phylogenetic analysis revealed that env mutations related to the loss of virulence might have occurred evolutionarily. Among these mutations, deletion of amino acid 236 in the V4 region of Env resulted in the loss of one N-glycosylation site that was crucial for virulence. Notably, the 236-deleted sequence represented a "vaccine-specific" mutation that was also found in wild EIAVLN40 strains based on single genome amplification (SGA) analysis. Therefore, our results suggest that the EIAV attenuated vaccine may originate from a branch of quasispecies of EIAVLN40. Generally, the presented results may increase our understanding of the attenuation mechanism of the EIAV vaccine and provide more information about the evolution of other lentiviruses.


Assuntos
Evolução Molecular , Genoma Viral , Vírus da Anemia Infecciosa Equina/genética , Vírus da Anemia Infecciosa Equina/patogenicidade , Quase-Espécies , Proteínas do Envelope Viral , Animais , Anemia Infecciosa Equina/prevenção & controle , Cavalos , Mutação , Filogenia , Análise de Sequência , Deleção de Sequência , Vacinas Atenuadas , Vacinas Virais , Virulência/genética
20.
Med Vet Entomol ; 33(3): 431-436, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30775793

RESUMO

Equine infectious anaemia (EIA) is a disease with an almost worldwide distribution, with several outbreaks having been reported recently in European countries. In Italy, two regions, Lazio and Abruzzo, are considered as endemic areas for this disease. In nature, the EIA virus is mechanically transmitted by biting flies such as tabanids (Diptera: Tabanidae), although few studies have investigated the epidemiological implications. In the present study, several sites characterized by different levels of EIA prevalence were sampled. In sites with high tabanid populations, a seasonal succession of tabanid species with a dual-peak corresponding to early active species (i.e. in June to July) and late active species (i.e. in August to September) was clearly observed. Moreover, a positive correlation was found between EIA prevalence and tabanid abundance and species richness, suggesting that tabanid diversity might extend the duration of the seasonal transmission period of EIA. Further observations are required to better assess how vector diversity influence EIA transmission.


Assuntos
Dípteros/fisiologia , Anemia Infecciosa Equina/epidemiologia , Insetos Vetores/fisiologia , Animais , Cavalos , Itália/epidemiologia , Dinâmica Populacional , Prevalência , Estações do Ano
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