RESUMO
Equine rotavirus A (ERVA) is the leading cause of diarrhea in neonatal foals and a major health problem to the equine breeding industry worldwide. The G3P[12] and G14P[12] ERVA genotypes are the most prevalent in foals with diarrhea. Control and prevention strategies include vaccination of pregnant mares with an inactivated vaccine containing a prototype ERVA G3P[12] strain with limited and controversial field efficacy. Here, we performed the molecular characterization of ERVA strains circulating in central Kentucky using fecal samples collected during the 2017 foaling season. The data indicated for the first time that the G14P[12] genotype is predominant in this region in contrast to a previous serotyping study where only G3 genotype strains were reported. Overall, analysis of antigenic sites in the VP7 protein demonstrated the presence of several amino acid substitutions in the epitopes exposed on the surface including a non-conserved N-linked glycosylation site (D123N) in G14P[12] strains, while changes in antigenic sites of VP8* were minor. Also, we report the successful isolation of three ERVA G14P[12] strains which presented a high identity with other G14 strains from around the world. These may constitute ideal reference strains to comparatively study the molecular biology of G3 and G14 strains and perform vaccine efficacy studies following heterologous challenge in the future.
Assuntos
Doenças dos Cavalos/virologia , Cavalos/virologia , Filogenia , Infecções por Rotavirus/veterinária , Rotavirus/classificação , Rotavirus/genética , Animais , Antígenos Virais/química , Antígenos Virais/genética , Sequência de Bases , Proteínas do Capsídeo/química , Proteínas do Capsídeo/genética , Linhagem Celular , Diarreia/virologia , Fezes/virologia , Feminino , Genoma Viral/genética , Genótipo , Doenças dos Cavalos/sangue , Doenças dos Cavalos/patologia , Kentucky , Gravidez , RNA Viral/genética , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/genética , Rotavirus/imunologia , Infecções por Rotavirus/sangue , Infecções por Rotavirus/patologia , Infecções por Rotavirus/virologia , Análise de Sequência de DNA , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/genética , Proteínas Virais/química , Proteínas Virais/genéticaRESUMO
The most used and reliable indicator of Equine infectious anemia virus (EIAV) infection is the detection of its specific antibodies in horse serum. In the present study, the performance of two commercial ELISA tests for the detection of EIAV antibodies as well as the potential advantages of their use as an EIAV infection screening tool were evaluated in 302 horse serum samples. Both ELISA assays showed 100% diagnostic sensitivity, and 92.3-94.3% diagnostic specificity. Discordant results were analyzed by immunoblot. The results showed that both ELISA tests are very efficient at detecting EIAV infected animals, allowing to identify a higher number of positive horse cases. Thus, ELISA assays can be useful tools in EIA control and eradication.
Assuntos
Anticorpos Antivirais/sangue , Ensaio de Imunoadsorção Enzimática , Anemia Infecciosa Equina/diagnóstico , Vírus da Anemia Infecciosa Equina/imunologia , Animais , Cavalos , Kit de Reagentes para DiagnósticoRESUMO
The most used and reliable indicator of equine infectious anemia virus (EIAV) infection is the detection of its specific antibodies in horse serum. In the present study, the performance of two commercial ELISA tests for the detection of EIAV antibodies as well as the potential advantages of their use as an EIAV infection screening tool were evaluated in 302 horse serum samples. Both ELISA assays showed 100% diagnostic sensitivity, and 92.3-94.3% diagnostic specificity. Discordant results were analyzed by immunoblot. The results showed that both ELISA tests are very efficient at detecting EIAV infected animals, allowing to identify a higher number of positive horse cases. Thus, ELISA assays can be useful tools in EIA control and eradication.
El mejor indicador de la infección por el virus de la anemia infecciosa equina (Equine infectious anemia virus, EIAV) es la detección de anticuerpos específicos en el suero del caballo. En el presente trabajo se evaluó la capacidad de detección de anticuerpos contra EIAV de dos equipos de ELISA comerciales utilizando 302 muestras de suero equino, así como las ventajas potenciales de su uso como herramientas de screening. Ambos ensayos de ELISA presentaron 100 % de sensibilidad diagnóstica y una especificidad diagnóstica del orden de 92,3 a 94,3 %. Las muestras discordantes fueron analizadas por inmunoblot. Los resultados mostraron que las dos pruebas ELISA son muy eficientes para detectar animales infectados por EIAV, al permitir identificar un mayor número de animales positivos que la prueba de inmunodifusión en gel de agar, oficialmente aprobada en la República Argentina para la certificación de los animales. Las pruebas de ELISA constituyen herramientas muy útiles en los programas de control y de erradicación de la infección por EIAV.
Assuntos
Animais , Anticorpos Antivirais/sangue , Ensaio de Imunoadsorção Enzimática , Anemia Infecciosa Equina/diagnóstico , Vírus da Anemia Infecciosa Equina/imunologia , Cavalos , Kit de Reagentes para DiagnósticoRESUMO
The most used and reliable indicator of equine infectious anemia virus (EIAV) infection is the detection of its specific antibodies in horse serum. In the present study, the performance of two commercial ELISA tests for the detection of EIAV antibodies as well as the potential advantages of their use as an EIAV infection screening tool were evaluated in 302 horse serum samples. Both ELISA assays showed 100% diagnostic sensitivity, and 92.3-94.3% diagnostic specificity. Discordant results were analyzed by immunoblot. The results showed that both ELISA tests are very efficient at detecting EIAV infected animals, allowing to identify a higher number of positive horse cases. Thus, ELISA assays can be useful tools in EIA control and eradication.(AU)
El mejor indicador de la infección por el virus de la anemia infecciosa equina (Equine infectious anemia virus, EIAV) es la detección de anticuerpos específicos en el suero del caballo. En el presente trabajo se evaluó la capacidad de detección de anticuerpos contra EIAV de dos equipos de ELISA comerciales utilizando 302 muestras de suero equino, así como las ventajas potenciales de su uso como herramientas de screening. Ambos ensayos de ELISA presentaron 100 % de sensibilidad diagnóstica y una especificidad diagnóstica del orden de 92,3 a 94,3 %. Las muestras discordantes fueron analizadas por inmunoblot. Los resultados mostraron que las dos pruebas ELISA son muy eficientes para detectar animales infectados por EIAV, al permitir identificar un mayor número de animales positivos que la prueba de inmunodifusión en gel de agar, oficialmente aprobada en la República Argentina para la certificación de los animales. Las pruebas de ELISA constituyen herramientas muy útiles en los programas de control y de erradicación de la infección por EIAV.(AU)
RESUMO
The most used and reliable indicator of Equine infectious anemia virus (EIAV) infection is the detection of its specific antibodies in horse serum. In the present study, the performance of two commercial ELISA tests for the detection of EIAV antibodies as well as the potential advantages of their use as an EIAV infection screening tool were evaluated in 302 horse serum samples. Both ELISA assays showed 100
diagnostic sensitivity, and 92.3-94.3
diagnostic specificity. Discordant results were analyzed by immunoblot. The results showed that both ELISA tests are very efficient at detecting EIAV infected animals, allowing to identify a higher number of positive horse cases. Thus, ELISA assays can be useful tools in EIA control and eradication.
RESUMO
The current production of inactivated vaccines for the prevention of equine alphavirus encephalitides caused by Eastern, Western and Venezuelan Equine Encephalitis viruses (EEEV, WEEV, VEEV) involves the manipulation of large quantities of infectious viral particles under biosafety level 3 containment laboratories with the potential risk of transmission to the operators. Moreover, these vaccines are not capable of inducing a long-lasting immunity. Modified live vaccines, which were also attempted, maintain residual virulence and neurotropism, causing disease in both horses and humans. Therefore, the production of an efficacious second generation vaccine which could be used in the prevention of alphavirus infection without the need to manipulate infectious viral particles under high biocontainment conditions could be of great benefit for the worldwide horse industry. Furthermore, equine alphaviruses are considered as biological threat agents. Subunit, chimeric, gene-deleted live mutants, DNA and adenovirus-vectored alphavirus vaccines have been evaluated; such approaches are reviewed in this work. Climate changes, together with modifications in bird and vector ecology, are leading to the arise of emerging pathogens in new geographical locations, and these zoonotic New World arboviruses are gaining concern. Novel vaccine development does show a promising future for prevention of these infections in both horses and humans.
Assuntos
Infecções por Alphavirus/veterinária , Alphavirus/imunologia , Encefalite Viral/veterinária , Doenças dos Cavalos/prevenção & controle , Doenças dos Cavalos/virologia , Vacinas Virais/imunologia , Infecções por Alphavirus/prevenção & controle , Infecções por Alphavirus/virologia , Animais , Pesquisa Biomédica/tendências , Encefalite Viral/prevenção & controle , Encefalite Viral/virologia , Cavalos , Vacinação/métodos , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/imunologia , Vacinas Atenuadas/isolamento & purificação , Vacinas de DNA/administração & dosagem , Vacinas de DNA/imunologia , Vacinas de DNA/isolamento & purificação , Vacinas de Produtos Inativados/administração & dosagem , Vacinas de Produtos Inativados/imunologia , Vacinas de Produtos Inativados/isolamento & purificação , Vacinas de Subunidades Antigênicas/administração & dosagem , Vacinas de Subunidades Antigênicas/imunologia , Vacinas de Subunidades Antigênicas/isolamento & purificação , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia , Vacinas Sintéticas/isolamento & purificação , Medicina Veterinária/tendências , Vacinas Virais/administração & dosagem , Vacinas Virais/isolamento & purificaçãoRESUMO
PREMISE OF THE STUDY: Microsatellite primers were developed in the native legume tree Anadenanthera colubrina var. cebil to study the genetic diversity and genetic structure in natural populations in Argentina. METHODS AND RESULTS: Nine microsatellite markers were identified using a genomic library enriched for tandemly repeated motifs, eight of which markers were polymorphic. The polymorphism of these markers was assessed by investigating 20 individuals for fragment polymorphism; three to 13 alleles were observed for each locus. Observed and expected heterozygosities ranged from 0.300 to 1.000 and from 0.463 to 0.900, respectively. CONCLUSIONS: These results confirm that these primers will be useful for investigating the genetic diversity and genetic structure of natural populations of A. colubrina var. cebil in future studies.
Assuntos
Fabaceae/genética , Repetições de Microssatélites/genética , Árvores/genética , Argentina , Primers do DNA/genética , Loci Gênicos/genética , Dados de Sequência MolecularRESUMO
BACKGROUND: Equine herpesvirus 2 is a gamma-herpesvirus that infects horses worldwide. Although EHV-2 has been implicated in immunosuppression in foals, upper respiratory tract disease, conjunctivitis, general malaise and poor performance, its precise role as a pathogen remains uncertain. The purpose of the present study was to analyse the incidence of EHV-2 in an Argentinean horse population and correlate it with age and clinical status of the animals. RESULTS: A serological study on 153 thoroughbred racing horses confirmed the presence of EHV-2 in the Argentinean equine population. A virus neutralization test showed a total of 79.7 % animals were sero-positive for EHV-2. An increase in antibodies titre with age as well as infection at earlier ages were observed.EHV-2 was isolated from 2 out of 22 nasal swabs from horses showing respiratory symptoms. The virus grew slowly and showed characteristic cytopathic effect after several blind passages on RK13 cells. The identity of the isolates was confirmed by nested PCR and restriction enzyme assay (REA). CONCLUSION: This is the first report on the presence of EHV-2 in Argentina and adds new data to the virus distribution map. Though EHV-2 was isolated from foals showing respiratory symptoms, further studies are needed to unequivocally associate this virus with clinical symptoms.