Identification of a divergent genotype of equine arteritis virus from South American donkeys.

A novel equine arteritis virus (EAV) was isolated and sequenced from feral donkeys in Chile. Phylogenetic analysis indicates that the new virus and South African asinine strains diverged at least 100 years from equine EAV strains. The results indicate that asinine strains belonged to a different EAV genotype.

Prevalência de anticorpos contra o vírus da arterite equina nas mesorregiões Noroeste, Centro Ocidental e Norte Central do Paraná / Prevalence of antibodies against equine viral arteritis virus in Northwest, Western Central and North Central Regions of the State of Paraná, Brazil

O objetivo deste estudo foi investigar a prevalência de anticorpos contra o vírus da arterite viral equina (EVAV) em equinos sadios criados nas mesorregiões Noroeste, Centro Ocidental e Norte Central do estado do Paraná. Após o cálculo do tamanho amostral, foram analisadas, utilizando a técnica de soroneutralização, amostras de soro sanguíneo de 653 equinos. Nenhum animal sororreagente foi encontrado nas mesorregiões Noroeste (0/236) e Centro Ocidental (0/99). Na mesorregião Norte Central a prevalência foi de 0,62% (2/318), totalizando 0,30%. Pode-se concluir que a arterite viral equina (AVE) ainda não representa um problema de importância epidemiológica nos equinos criados nas mesorregiões paranaenses estudadas.(AU)

The prevalence of antibodies against equine viral arteritis virus (EVAV) in healthy horses raised in Northwest, Western Central and North Central regions of the State of Paraná, Brazil was investigated. According to calculated sample size, serum samples of 653 horses were analyzed through standard virus neutralization test. No horse had antibodies to EVAV in Northwest (0/236) and in Western Central (0/99) regions. In North Central region frequency was 0.62% (2/318), with an overall prevalence of 0.30%. It can be concluded that EVA does not represent a problem of epidemiological importance in the studied regions of Paraná.(AU)

Prevalence of antibodies against equine viral arteritis virus in Northwest, Western Central and North Central Regions of the State of Paraná, Brazil / Prevalência de anticorpos contra o vírus da arterite equina nas mesorregiões Noroeste, Centro Ocidental e Norte Central do Paraná

The prevalence of antibodies against equine viral arteritis virus (EVAV) in healthy horses raised in Northwest, Western Central and North Central regions of the State of Paraná, Brazil was investigated. According to calculated sample size, serum samples of 653 horses were analyzed through standard virus neutralization test. No horse had antibodies to EVAV in Northwest (0/236) and in Western Central (0/99) regions. In North Central region frequency was 0.62% (2/318), with an overall prevalence of 0.30%. It can be concluded that EVA does not represent a problem of epidemiological importance in the studied regions of Paraná.(AU)

O objetivo deste estudo foi investigar a prevalência de anticorpos contra o vírus da arterite viral equina (EVAV) em equinos sadios criados nas mesorregiões Noroeste, Centro Ocidental e Norte Central do estado do Paraná. Após o cálculo do tamanho amostral, foram analisadas, utilizando a técnica de soroneutralização, amostras de soro sanguíneo de 653 equinos. Nenhum animal sororreagente foi encontrado nas mesorregiões Noroeste (0/236) e Centro Ocidental (0/99). Na mesorregião Norte Central a prevalência foi de 0,62% (2/318), totalizando 0,30%. Pode-se concluir que a arterite viral equina (AVE) ainda não representa um problema de importância epidemiológica nos equinos criados nas mesorregiões paranaenses estudadas.(AU)

Prevalence of antibodies against equine viral arteritis virus in Northwest, Western Central and North Central Regions of the State of Paraná, Brazil / Prevalência de anticorpos contra o vírus da arterite equina nas mesorregiões Noroeste, Centro Ocidental e Norte Central do Paraná

The prevalence of antibodies against equine viral arteritis virus (EVAV) in healthy horses raised in Northwest, Western Central and North Central regions of the State of Paraná, Brazil was investigated. According to calculated sample size, serum samples of 653 horses were analyzed through standard virus neutralization test. No horse had antibodies to EVAV in Northwest (0/236) and in Western Central (0/99) regions. In North Central region frequency was 0.62% (2/318), with an overall prevalence of 0.30%. It can be concluded that EVA does not represent a problem of epidemiological importance in the studied regions of Paraná.

O objetivo deste estudo foi investigar a prevalência de anticorpos contra o vírus da arterite viral equina (EVAV) em equinos sadios criados nas mesorregiões Noroeste, Centro Ocidental e Norte Central do estado do Paraná. Após o cálculo do tamanho amostral, foram analisadas, utilizando a técnica de soroneutralização, amostras de soro sanguíneo de 653 equinos. Nenhum animal sororreagente foi encontrado nas mesorregiões Noroeste (0/236) e Centro Ocidental (0/99). Na mesorregião Norte Central a prevalência foi de 0,62% (2/318), totalizando 0,30%. Pode-se concluir que a arterite viral equina (AVE) ainda não representa um problema de importância epidemiológica nos equinos criados nas mesorregiões paranaenses estudadas.

Development of a peptide ELISA for the diagnosis of Equine arteritis virus.

A peptide-based indirect ELISA was developed to detect antibodies against Equine arteritis virus (EAV). Two peptides for epitope C of protein GP5 and fragment E of protein M were designed, synthesized, purified and used as antigens either alone or combined. Ninety-two serum samples obtained from the 2010 Equine viral arteritis outbreak, analyzed previously by virus neutralization, were evaluated by the ELISA here developed. The best resolution was obtained using peptide GP5. The analysis of the inter- and intraplate variability showed that the assay was robust. The results allow concluding that this peptide-based ELISA is a good alternative to the OIE-prescribed virus neutralization test because it can be standardized between laboratories, can serve as rapid screening, can improve the speed of diagnosis of EAV-negative horses and can be particularly useful for routine surveillance in large populations.

The equine arteritis virus isolate from the 2010 Argentinian outbreak.

A semen sample from a stallion infected during the 2010 equine arteritis virus (EAV) outbreak was received for viral isolation prior to castration of the animal. The virus was identified using a polyclonal antibody immunofluorescence test. Reverse-transcription polymerase chain reaction (RT-PCR) was used to amplify a region of the GP5 gene with primers GL105F and GL673R. The PCR products were purified and sequences of both strands were determined in a MegaBACE™1000 with inner primers CR2 and EAV32. A phylogenetic dataset was built with the previously reported sequences of five strains isolated in Argentina, together with a group of selected sequences obtained from GenBank. The unrooted neighbour-joining tree was constructed using molecular evolutionary genetic analysis (MEGA) and bootstrap analyses were conducted using 1,000 replicate datasets. Evolutionary distances were computed using the maximum composite likelihood method. A NetNGlyc server analysis at the Technical University of Denmark (www.cbs.dtu.dk/services/NetNGlyc/) was used to predict N-glycosylation in GP5 sequences. The phylogenetic analysis revealed that the new strain GLD-LP-ARG), together with other strains previously isolated, belongs to the European group EU-1 but in a different branch. The new strain shows 99% nucleotide identity with strain Al1and 98.1% with the Belgian strain 08P178. Persistently infected stallions and their cryopreserved semen constitute a reservoir of EAV, which ensures its persistence in the horse population around the world. These findings reinforce the importance of careful monitoring of persistently infected stallions, as well as semen straws, by RT-PCR or test mating, in accordance with national regulations.

ELA-DRA polymorphisms are not associated with Equine Arteritis Virus infection in horses from Argentina.

Polymorphisms at Major Histocompatibility Complex (MHC) genes have been associated with resistance/susceptibility to infectious diseases in domestic animals. The aim of this investigation was to evaluate whether polymorphisms of the DRA gene the Equine Lymphocyte Antigen is associated with susceptibility to Equine Arteritis Virus (EAV) infection in horses in Argentina. The equine DRA gene was screened for polymorphisms using Pyrosequencing® Technology which allowed the detection of three ELA-DRA exon 2 alleles. Neither allele frequencies nor genotypic differentiation exhibited any statistically significant (P-values=0.788 and 0.745) differences between the EAV-infected and no-infected horses. Fisher's exact test and OR calculations did not show any significant association. As a consequence, no association could be established between the serological condition and ELA-DRA.

Extended phylogeny of the equine arteritis virus sequences including South American sequences.

OBJECTIVE: To perform genetic analysis of the ORF5 of equine arteritis virus (EAV) may provide new insights into the genetic evolution and origin of the Argentinean EAV sequences. METHODS: A total of 76 sequences were analyzed by neighbor joining (NJ), maximum parsimony and maximum likelihood algorithms. The analysis of the selective pressures was performed using the Tajima's test. RESULTS: The trees showed similar topologies. Two clades were identified: the first clade was formed by strains isolated mainly from a donkey, whereas the second clade presented four large groups from different geographic regions exclusively from Equus caballus. In this clade, we identified a group formed by South African and another one by South American and European sequences. In the latter, the monophyletic group was formed by seven Argentinean sequences. In the NJ tree, we identified a group formed by six Argentinean sequences. The Tajima's test showed a D value of 1.73663, indicating that the sequences analyzed follow a neutral evolution model. CONCLUSION: We concluded that the Argentinean sequences have a paraphyletic origin and that the fixation of point mutation might follow the neutral model evolution; however, we identified purifying pressures that may be involved in the differentiation of the EAV sequences.

Equine arteritis virus: a new isolate from the presumable first carrier stallion in Argentina and its genetic relationships among the four reported unique Argentinean strains.

Equine arteritis virus (EAV) was isolated from a testicle of the presumable first stallion infected with EAV in Argentina. This virus isolate (named LT-LP-ARG) was confirmed by GP5-specific PCR and indirect immunofluorescence assays. The PCR product was sequenced, and the phylogenetic analysis revealed that the LT-LP-ARG strain of EAV forms a monophyletic group, together with other strains previously isolated in our laboratory (LP02 group). However, all Argentinean EAV strains belong to a polyphyletic group. We believe that the virus isolate presented in this report could be the origin of EAV infection in our country.

The first isolation of equine arteritis virus in Argentina.

This paper describes the first isolation of equine arteritis virus (EAV) in Argentina. The virus was isolated from the semen of an imported seropositive stallion held in isolation at a breeding farm in Tandil in the Buenos Aires Province. In addition, viral nucleic acid was detected in seminal plasma using the reverse-transcription polymerase chain reaction. The isolated virus was propagated in cell cultures and confirmed as EAV by indirect immunofluorescence and virus neutralisation, using a serum specific for the reference Bucyrus strain of EAV. As far as the authors are aware, this is the first time that EAV has been isolated in South America. The equine industry is very important for Argentina and international movement of horses is very intensive. This finding may have effects on the international trade of horses and semen from Argentina.

Determinaçäo sorológica da arterite viral eqüina em eqüinos hígidos, com abortamento e com sintomas de alteraçäo do sistema respiratório / Serological determination of equine arteritis virus in horses with abortion and symptoms of respiratory alteration

Foi pesquisada a presença de anticorpos antivírus da arterite viral dos eqüinos em cavalos criados no estado de Säo Paulo que apresentaram sintomas de alteraçäo do sistema respiratório ou abortamento, e comparados os resultados com animais criados nas mesmas propriedades e que näo apresentavam os referidos sintomas. Os resultados positivos observados nos dois grupos, de 23,52 por cento e 10,34 por cento, respectivamente, para o grupo de animais com quadro respiratório e abortamento, näo foi estatisticamente diferente dos animais assintomáticos (19,33 por cento). Considerando-se a raça dos animais, pode-se observar maior ocorrência de animais soropositivos nas raças Mangalarga, Arabe e Quarto de Milha, quando comparados aos das raças Andaluz e Puro-Sangue Inglês, bem como aos mestiços.

Síndrome reprodutiva e respiratória dos suínos: uma breve revisäo / Porcine reproductive and respiratory syndrome: a brief review

A síndrome reprodutiva e respiratória dos suínos (Porcine Reproductive and Respiratory Syndrome - PRRS) é uma doença relativamente nova dos suínos que foi detectada primeiramente em 1985 nos Estados Unidos, e em 1990 no continente Europeu. A síndrome é causada pelo PRRS vírus (PRRSV), o qual foi incluído em uma nova família de vírus, a Arteriviridae. A infecçäo pelo PRRSV causa problemas reprodutivos em fêmeas gestantes, o quais säo caracterizados por abortos no final da gestaçäo e/ou parto precoce, onde pode-se observar um elevado número de fetos mumificados e natimortos; leitöes que nascem infectados säo fracos e economicamente inviáveis. Os problemas respiratórios causados pela infecçäo pelo PRRSV podem se manifestar em suínos de todas as faixas etárias, e säo semelhantes a influenza. Embora PRRS tem sido detectada na maioria dos países em que a suinocultura tem importância econômica significativa, näo há informaçöes publicadas a respeito da doença ou do vírus no Brasil. No entanto, devido as perdas econômicas significativas que essa síndrome causou nos países já afetados, e da possibilidade do vírus ser eventualmente introduzido nos rebanhos brasileiros, é necessário reconhecer a doença imediatamente, e tomar as devidas medidas para o diagnóstico e controle em casos de surtos de problemas reprodutivos e respiratórios.