Detection of Vaccinia Virus in Dairy Cattle Serum Samples from 2009, Uruguay.

We detected orthopoxvirus in 28 of 125 serum samples collected during 2009 from cattle in Uruguay. Two samples were PCR-positive for vaccinia virus and had sequences similar to those for vaccinia virus associated with outbreaks in Brazil. Autochthonous circulation of vaccinia virus in Uruguay and other South American countries cannot be ruled out.

Field Evaluation of Commercial Vaccines against Infectious Bovine Rhinotracheitis (Ibr) Virus Using Different Immunization Protocols.

Bovine alphaherpesvirus 1 is ubiquitous in cattle populations and is associated with several clinical syndromes, including respiratory disease, genital disease, infertility and abortions. Control of the virus in many parts of the world is achieved primarily through vaccination with either inactivated or live modified viral vaccines. The objective of this study was to evaluate the performance of four commercially available BoHV-1 vaccines commonly used in Central and South America. Animals were divided into eight groups and vaccinated on days 0 and 30. Groups 1 to 4 received two doses of four different BoHV-1 commercial vaccines (named A to D). Groups 5 and 6 received vaccine D plus a vaccine for either Clostridial or Food-and-Mouth-Disease (FMD), respectively. Group 7 received one dose of two different brands of reproductive vaccines. Serum samples were collected from all animals on days 0, 30 and 60 to evaluate neutralizing and isotype-specific (IgG1 and IgG2) antibodies. Of the four commercial vaccines evaluated, only vaccine A induced neutralizing antibodies to titers ≥ 1:8 in 13/15 (86%) of the animals 60 days post-vaccination. Levels of IgG2 antibody increased in all groups, except for group 2 after the first dose of vaccine B. These results show that only vaccine A induced significant and detectable levels of BoHV-1-neutralizing antibodies. The combination of vaccine D with Clostridial or FMD vaccines did not affect neutralizing antibody responses to BoHV-1. The antibody responses of three of the four commercial vaccines analyzed here were lower than admissible by vaccine A. These results may be from vaccination failure, but means to identify the immune signatures predictive of clinical protection against BoHV-1 in cattle should also be considered.

Comparison between DNA Detection in Trigeminal Nerve Ganglia and Serology to Detect Cattle Infected with Bovine Herpesviruses Types 1 and 5.

Bovine herpesviruses (BoHVs) types 1 (BoHV-1) and 5 (BoHV-5) are alphaherpesviruses of major importance to the bovine production chain. Such viruses are capable of establishing latent infections in neuronal tissues. Infected animals tend to develop a serological response to infection; however, such response-usually investigated by antibody assays in serum-may eventually not be detected in laboratory assays. Nevertheless, serological tests such as virus neutralization (VN) and various enzyme-linked immunosorbent assays (ELISAs) are widely employed to check individual or herd status of BoHV infections. The correlation between detection of antibodies and the presence of viral nucleic acids as indicatives of infection in infected cattle has not been deeply examined. In order to investigate such correlation, 248 bovine serum samples were tested by VN to BoHV-1 and BoHV-5, as well as in a widely employed (though not type-differential) gB ELISA (IDEXX IBR gB X2 Ab Test) in search for antibodies to BoHVs. Immediately after blood withdrawal, cattle were slaughtered and trigeminal ganglia (TG) excised for DNA extraction and viral nucleic acid detection (NAD) by nested PCR. Neutralizing antibodies to BoHV-1 and/or BoHV-5 were detected in 44.8% (111/248) of sera, whereas the gB ELISA detected antibodies in 51.2% (127/248) of the samples. However, genomes of either BoHV-1, BoHV-5, or both, were detected in TGs of 85.9% (213/248) of the animals. These findings reveal that the assays designed to detect antibodies to BoHV-1 and/or BoHV-5 employed here may fail to detect a significant number of latently infected animals (in this study, 35.7%). From such data, it is clear that antibody assays are poorly correlated with detection of viral genomes in BoHV-1 and BoHV-5-infected animals.

Ocorrência de anticorpos anti-Neospora caninum em pequenas propriedades leiteiras do Uruguai / Occurrence of anti-Neospora caninum antibodies in small dairy farms in Uruguay

Neosporose é uma doença de distribuição mundial causada por um protozoário (Apicomplexa, Sarcocystidae), denominado Neospora caninum (N. caninum). Na América Latina, o protozoário foi diagnosticado no Uruguai, Brasil, Argentina, Chile, Paraguai e Peru. No Uruguai a prevalência em rebanhos leiteiros não foi determinada, havendo somente levantamentos sorológicos de algumas regiões do país em propriedades rurais de médio e grande porte. O objetivo deste trabalho foi determinar a presença de animais sorologicamente positivos contra N. caninum em bacias leiteiras de pequenas propriedades com baixos recursos socioeconômicos da zona central do Uruguai (Estados de Durazno e Tacuarembó). Utilizando um Kit de ELISA comercial, foram analisados 734 soros provenientes de vacas leiteiras adultas, obtendo-se 211 positivos (28,8 por cento), 517 negativos (70,5 por cento) e seis animais com resultado não determinado (0,7 por cento). Nossos resultados demonstram a exposição destes rebanhos ao parasito, sendo este o primeiro inquérito sorológico de N. caninum em bacias leiteiras de pequenas propriedades no Uruguai.

Neosporosis is a worldwide disease caused by a protozoan (Apicomplexa, Sarcocystidae), called Neospora caninum (N. caninum). In Latin America was diagnosed in Uruguay, Brazil, Argentina, Chile, Paraguay and Peru. In Uruguay, the prevalence in dairy cattle is undetermined, with only a few reports in some areas from medium and large farmers. The main of this study was to determine the presence of serologically positive animals against N. caninum in small dairy farmers in critical context from central region of Uruguay (Departments of Durazno and Tacuarembó). Using a commercial ELISA kit, 734 sera of adult dairy cows were analyzed, resulting in 211 positive (28.8 percent), 517 negative (70.5 percent) and six animals with uncertain outcome (0.7 percent). The results demonstrated the exposure of cattle to the parasite, which is the first serological survey of N. caninum in basins of small dairy farmers in critical context in Uruguay.

Tissue preservation and cell culture of Przewalskii´s horse (Equus przewalskii): an endangered species / Preservação de tecidos e cultura de células do cavalo de Przewalski (Equus przewalskii): uma espécie em extinção

The Przewalskii´s horse or Mongolian wild horse (Equus przewalskii, Poljakov, 1881) is presently the only species of wild horse in existence. Originally from Asia, it is, classified as in extremely high risk of extinction which puts the species in the seriously threatened category. The aim of this work was the preservation of tissues and the development of cell cultures from tissue samples obtained from a Przewalskii´s horse after its death. Biopsies of skin, skeletal and cardiac muscle, and ear cartilage were removed from a recently dead horse, added to Phosphate Buffer Saline (PBS) and refrigerated until processing. Some of the samples were frozen in liquid nitrogen and the other was grown as explants to generate fibroblast cell monolayers. The cell cultures obtained, were subsequently propagated with low passages, and frozen in liquid nitrogen, thus avoiding genetic and phenotypic alterations. The tissues and cell cultures were thawed to ascertain their viability by checking its progressive grow in a flask. It was not possible to obtain cultures from cardiac muscle. A bank of tissues and cells from the single Przewalskii´s horse that existed in Uruguay was generated, and can be used for scientific purposes and for the conservation of the species in the future