WITHDRAWN: Reconstructing the environmental impact of mining on mountain lakes.

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Molecular Epidemiology of Rotavirus A in Calves: Evolutionary Analysis of a Bovine G8P[11] Strain and Spatio-Temporal Dynamics of G6 Lineages in the Americas.

Rotavirus A (RVA) causes diarrhea in calves and frequently possesses the G6 and P[5]/P[11] genotypes, whereas G8 is less common. We aimed to compare RVA infections and G/P genotypes in beef and dairy calves from major livestock regions of Argentina, elucidate the evolutionary origin of a G8 strain and analyze the G8 lineages, infer the phylogenetic relationship of RVA field strains, and investigate the evolution and spatio-temporal dynamics of the main G6 lineages in American countries. Fecal samples (n = 422) from diarrheic (beef, 104; dairy, 137) and non-diarrheic (beef, 78; dairy, 103) calves were analyzed by ELISA and semi-nested multiplex RT-PCR. Sequencing, phylogenetic, phylodynamic, and phylogeographic analyses were performed. RVA infections were more frequent in beef (22.0%) than in dairy (14.2%) calves. Prevalent genotypes and G6 lineages were G6(IV)P[5] in beef (90.9%) and G6(III)P[11] (41.2%) or mixed genotypes (23.5%) in dairy calves. The only G8 strain was phylogenetically related to bovine and artiodactyl bovine-like strains. Re-analyses inside the G8 genotype identified G8(I) to G8(VIII) lineages. Of all G6 strains characterized, the G6(IV)P[5](I) strains from "Cuenca del Salado" (Argentina) and Uruguay clustered together. According to farm location, a clustering pattern for G6(IV)P[5] strains of beef farms was observed. Both G6 lineage strains together revealed an evolutionary rate of 1.24 × 10-3 substitutions/site/year, and the time to the most recent common ancestor was dated in 1853. The most probable ancestral locations were Argentina in 1981 for G6(III) strains and the USA in 1940 for G6(IV) strains. The highest migration rates for both G6 lineages together were from Argentina to Brazil and Uruguay. Altogether, the epidemiology, genetic diversity, and phylogeny of RVA in calves can differ according to the production system and farm location. We provide novel knowledge about the evolutionary origin of a bovine G8P[11] strain. Finally, bovine G6 strains from American countries would have originated in the USA nearly a century before its first description.

The hidden microbial ecosystem in the perennial ice from a Pyrenean ice cave.

Over the last years, perennial ice deposits located within caves have awakened interest as places to study microbial communities since they represent unique cryospheric archives of climate change. Since the beginning of the twentieth century, the temperature has gradually increased, and it is estimated that by the end of this century the increase in average temperature could be around 4.0°C. In this context of global warming the ice deposits of the Pyrenean caves are undergoing a significant regression. Among this type of caves, that on the Cotiella Massif in the Southern Pyrenees is one of the southernmost studied in Europe. These types of caves house microbial communities which have so far been barely explored, and therefore their study is necessary. In this work, the microbial communities of the Pyrenean ice cave A294 were identified using metabarcoding techniques. In addition, research work was carried out to analyze how the age and composition of the ice affect the composition of the bacterial and microeukaryotic populations. Finally, the in vivo effect of climate change on the cellular machinery that allow microorganisms to live with increasing temperatures has been studied using proteomic techniques.

Parasitemia and Associated Immune Response in Pregnant and Non-Pregnant Beef Cows Naturally Infected With Neospora caninum.

The aim of this longitudinal study was to characterize the parasitemia of Neospora caninum and the associated immunological parameters in naturally infected beef cows for 10 months. The following groups were established: Neospora caninum seropositive pregnant cows (+Preg, n = 7), seropositive non-pregnant cows (+Npreg, n = 7), seronegative pregnant cows (-Preg, n = 4), and seronegative non-pregnant cows (-Npreg, n = 4). Several samples were obtained for absolute and relative leukocyte counting, cytokines IL-10, IL-12, α-TNF, and γ-IFN quantification, specific IgG, IgG1, and IgG2 and avidity and N. caninum DNA molecular detection and quantification. The +Preg group had a higher frequency and concentration of N. caninum DNA in PBMC in the last third of pregnancy compared to +Npreg (p <0.05), with 22 and 8% of detection, respectively. Parasitemia correlated positively with IgG titers and negatively with IgG1/IgG2 ratio (p <0.05). On day 222 of the assay, the +Preg group had the lowest total leukocyte counting (p <0.05). The +Preg group had a higher concentration of IgG and higher avidity in the last third of gestation compared to +Npreg (p <0.05). Avidity correlated with total IgG and IgG2 (p <0.05). All +Preg cows gave birth to clinically healthy but seropositive calves before colostrum intake, therefore, the congenital transmission was 100% efficient. Only a complete N. caninum genotype from a placenta and a partial genotype from cow #3 of the group +Preg were achieved by multilocus microsatellite analysis. Overall, N. caninum parasitemia is frequent in seropositive beef cows during the last third of gestation. This correlates with higher antibody levels and a decrease in total leukocyte counting. The precise timing of the parasitemia may be used for diagnosis purposes and/or for design strategies to avoid vertical transmission. Further studies are needed to identify the immune molecular mechanisms that favor parasitemia during gestation in chronically infected cattle.

The untapped potential of macrofossils in ancient plant DNA research.

The rapid development of ancient DNA analysis in the last decades has induced a paradigm shift in ecology and evolution. Driven by a combination of breakthroughs in DNA isolation techniques, high-throughput sequencing, and bioinformatics, ancient genome-scale data for a rapidly growing variety of taxa are now available, allowing researchers to directly observe demographic and evolutionary processes over time. However, the vast majority of paleogenomic studies still focus on human or animal remains. In this article, we make the case for a vast untapped resource of ancient plant material that is ideally suited for paleogenomic analyses: plant remains, such as needles, leaves, wood, seeds, or fruits, that are deposited in natural archives, such as lake sediments, permafrost, or even ice caves. Such plant remains are commonly found in large numbers and in stratigraphic sequence through time and have so far been used primarily to reconstruct past local species presences and abundances. However, they are also unique repositories of genetic information with the potential to revolutionize the fields of ecology and evolution by directly studying microevolutionary processes over time. Here, we give an overview of the current state-of-the-art, address important challenges, and highlight new research avenues to inspire future research.

Glacial Ice Age Shapes Microbiome Composition in a Receding Southern European Glacier.

Glaciers and their microbiomes are exceptional witnesses of the environmental conditions from remote times. Climate change is threatening mountain glaciers, and especially those found in southern Europe, such as the Monte Perdido Glacier (northern Spain, Central Pyrenees). This study focuses on the reconstruction of the history of microbial communities over time. The microorganisms that inhabit the Monte Perdido Glacier were identified using high-throughput sequencing, and the microbial communities were compared along an altitudinal transect covering most of the preserved ice sequence in the glacier. The results showed that the glacial ice age gradient did shape the diversity of microbial populations, which presented large differences throughout the last 2000 years. Variations in microbial community diversity were influenced by glacial conditions over time (nutrient concentration, chemical composition, and ice age). Some groups were exclusively identified in the oldest samples as the bacterial phyla Fusobacteria and Calditrichaeota, or the eukaryotic class Rhodophyceae. Among groups only found in modern samples, the green sulfur bacteria (phylum Chlorobi) stood out, as well as the bacterial phylum Gemmatimonadetes and the eukaryotic class Tubulinea. A patent impact of human contamination was also observed on the glacier microbiome. The oldest samples, corresponding to the Roman Empire times, were influenced by the beginning of mining exploitation in the Pyrenean area, with the presence of metal-tolerant microorganisms. The most recent samples comprise 600-year-old ancient ice in which current communities are living.

Genomic diversity and phylodynamic of bovine viral diarrhea virus in Argentina.

Bovine viral diarrhea virus (BVDV) is an important pathogen of ruminants worldwide and is characterized by high genetic diversity and a wide range of clinical presentations. In Argentina, several studies have evaluated the genetic diversity of BVDV but no phylodynamic study has been published yet. In this study, a comprehensive compilation and update of Argentinean BVDV sequences were performed, and the evolutionary history of BVDV was characterized by phylodynamic analyses based on the 5´UTR. Although BVDV-1b and BVDV-1a were the most frequent subtypes, novel subtypes for Argentina, 1e and 1i, were identified. The phylodynamic analysis suggested that BVDV started its diversification in the mid-1650s with an exponential increase in viral diversity since the late 1990s, possibly related to the livestock expansion and intensification in the country. Evolutionary rate in the 5´UTR was faster for BVDV-1a than for BVDV-1b, and both subtypes presented an endemic nature according to the demographic reconstructions. The current study contributes to clarify the evolutionary history of BVDV in the main cattle region of the country and provides useful information about the epidemiology and future development of diagnostic and control tools in Argentina.

Genetic characterization of bovine herpesvirus 4 (BoHV-4) isolates from Argentine cattle suggests a complex evolutionary scenario.

Bovine herpevsirus 4 (BoHV-4) is a gammaherpesvirus that has been associated with different clinical conditions in cattle. In Argentina, BoHV-4 was detected in diverse bovine samples. The aim of this study was to analyze the genetic relationship of 48 field BoHV-4 strains isolated from cattle in Argentina. According to thymidine kinase (tk) gene sequences, BoHV-4 isolates belong to genotypes 1, 2 and 3. Phylogenetic analyses confirmed the presence of the three previously described viral genotypes. However, some of the studied isolates presented conflicting phylogenetic signals between the studied markers. This suggests a complex evolutionary background, that is a history of recombination, incomplete lineage sorting (deep coalescence) or a combination of these, which requires further study. These potential events make difficult the diagnosis of BoHV-4 from clinical samples of cattle and may pose a significant problem for the control of the virus in the herds.

Characterization of the first bovine gammaherpesvirus 4 strain isolated from an aborted bovine fetus in Argentina.

Bovine herpesvirus 4 (BoHV-4) is increasingly believed to be responsible for several disorders of the bovine reproductive tract. The first characterization of BoHV-4 in Argentina was from samples from an aborted fetus. Argentinean isolates are highly diverse and are phylogenetically grouped in three genotypes. In this study, we describe the isolation of BoHV-4 from a bovine fetus with a gestational age of 8 months and without macroscopic lesions. Genetic analyses revealed that the isolated strain belongs to genotype 2. This is the first report on the presence of infectious BoHV-4 in tissues from an aborted bovine fetus.

Delayed type hypersensitivity induced by intradermal inoculation of a Neospora caninum tachyzoite antigen in previously exposed cattle.

The aim of this study was to evaluate delayed type hypersensitivity (DTH) induced by the intradermal inoculation of a Neospora caninum tachyzoite soluble lysate in cattle previously exposed with the protozoa. Four experimental groups were selected according to the prior exposure to N. caninum antigen. All cows were intradermally injected with a N. caninum tachyzoite soluble lysate and skinfold thickness growth at the inoculation sites was measured at 0, 24, 48, 72 and 96 h post inoculation (hpi). Additionally, specific antibodies and IFN-γ production were assessed. Cows experimentally infected with live N. caninum tachyzoites and cows naturally exposed to N. caninum developed skin reactions compatible with DTH between 24 and 96 hpi (p < 0.05). Moreover, cows inoculated with an experimental N. caninum vaccine and cows without evidence of exposure to N. caninum did not show a significant increase in skin thickness (p > 0.05). Furthermore, serological status of the animals was not modified due to the intradermal inoculation. The highest IFN-γ production was observed at 15 days after intradermal inoculation (p < 0.05). Therefore, these results suggest that cattle previously exposed to N. caninum develop a reaction compatible with DTH which could be useful as in vivo cell mediated immunity parameter for assessed bovine neosporosis.

Dual natural infection with bovine viral diarrhea virus -1 and -2 in a stillborn calf: tissue distribution and molecular characterization.

Dual infections with both bovine viral diarrhea virus (BVDV)-1 and -2 seem to be unusual. The aim of this study was to describe an infection with both BVDV genotypes in a stillborn calf. Virus isolation and phylogenetic analyses of the 5´UTR and NS5B regions confirmed the presence of BVDV-1b and -2b in spleen and lung, whereas BVDV-2b was also detected in brain, heart, liver, kidney and, fluid of cavities. These results confirm that dual infections with both BVDV-1 and BVDV-2 species can occur naturally and their tissue distribution can be different.

Interaction of bovine viral diarrhea virus with bovine cumulus-oocyte complex during IVM: Detection in permissive cells.

Structural changes in the zona pellucida (ZP) of bovine oocytes seem to modulate their interaction with various viral agents, facilitating the viral infection in in vitro production systems. To evaluate the susceptibility of bovine oocytes to noncytopathogenic bovine viral diarrhea virus (ncp-BVDV), cumulus-oocyte complexes were exposed to 10(7) ​tissue culture-infective doses (TCID50)/mL of an ncp-BVDV strain during IVM (in vitro maturation). After that, cumulus cells and the ZP were removed by hyaluronidase and pronase treatment, respectively, and the percentages of oocytes with polar body were analyzed as a sign of nuclear maturation. After passage through cell culture, the virus was isolated from granulosa cells, ZP-free mature oocytes, and ZP-intact mature oocytes. These results were confirmed by reverse transcription-polymerase chain reaction. After consecutive washes, the virus remained associated with ZP-free oocytes, maintaining its replication and infectivity in permissive cells. Based on these findings, it is concluded that the classical viral isolation procedure has a predictive value to detect BVDV associated with ZP-free oocytes and that it was novelty demonstrated that both washing and trypsin treatment of oocytes were ineffective to remove BVDV infection.

Molecular Characterization of the First Bovine Herpesvirus 4 (BoHV-4) Strains Isolated from In Vitro Bovine Embryos production in Argentina.

Bovine herpesvirus 4 (BoHV-4) is increasingly considered as responsible for various problems of the reproductive tract. The virus infects mainly blood mononuclear cells and displays specific tropism for vascular endothelia, reproductive and fetal tissues. Epidemiological studies suggest its impact on reproductive performance, and its presence in various sites in the reproductive tract highlights its potential transmission in transfer-stage embryos. This work describes the biological and genetic characterization of BoHV-4 strains isolated from an in vitro bovine embryo production system. BoHV-4 strains were isolated in 2011 and 2013 from granulosa cells and bovine oocytes from ovary batches collected at a local abattoir, used as "starting material" for in vitro production of bovine embryos. Compatible BoHV-4-CPE was observed in the co-culture of granulosa cells and oocytes with MDBK cells. The identity of the isolates was confirmed by PCR assays targeting three ORFs of the viral genome. The phylogenetic analyses of the strains suggest that they were evolutionary unlinked. Therefore it is possible that BoHV-4 ovary infections occurred regularly along the evolution of the virus, at least in Argentina, which can have implications in the systems of in vitro embryo production. Thus, although BoHV-4 does not appear to be a frequent risk factor for in vitro embryo production, data are still limited. This study reveals the potential of BoHV-4 transmission via embryo transfer. Moreover, the high variability among the BoHV-4 strains isolated from aborted cows in Argentina highlights the importance of further research on the role of this virus as an agent with the potential to cause reproductive disease in cattle. The genetic characterization of the isolated strains provides data to better understand the pathogenesis of BoHV-4 infections. Furthermore, it will lead to fundamental insights into the molecular aspects of the virus and the means by which these strains circulate in the herds.

A Neospora caninum vaccine using recombinant proteins fails to prevent foetal infection in pregnant cattle after experimental intravenous challenge.

The aim of the present study was to evaluate the immunogenicity and protective efficacy of rNcSAG1, rNcHSP20 and rNcGRA7 recombinant proteins formulated with immune stimulating complexes (ISCOMs) in pregnant heifers against vertical transmission of Neospora caninum. Twelve pregnant heifers were divided into 3 groups of 4 heifers each, receiving different formulations before mating. Immunogens were administered twice subcutaneously: group A animals were inoculated with three recombinant proteins (rNcSAG1, rNcHSP20, rNcGRA7) formulated with ISCOMs; group B animals received ISCOM-MATRIX (without antigen) and group C received sterile phosphate-buffered saline (PBS) only. The recombinant proteins were expressed in Escherichia coli and purified nickel resin. All groups were intravenously challenged with the NC-1 strain of N. caninum at Day 70 of gestation and dams slaughtered at week 17 of the experiment. Heifers from group A developed specific antibodies against rNcSAG1, rNcHSP20 and rNcGRA7 prior to the challenge. Following immunization, an statistically significant increase of antibodies against rNcSAG1 and rNcHSP20 in all animals of group A was detected compared to animals in groups B and C at weeks 5, 13 and 16 (P<0.001). Levels of antibodies against rNcGRA7 were statistical higher in group A animals when compared with groups B and C at weeks 5 and 16 (P>0.001). There were no differences in IFN-γ production among the experimental groups at any time point (P>0.05). Transplacental transmission was determined in all foetuses of groups A, B and C by Western blot, immunohistochemistry and nested PCR. This work showed that rNcSAG1, rNcHSP20 and rNcGRA7 proteins while immunogenic in cattle failed to prevent the foetal infection in pregnant cattle challenged at Day 70 of gestation.

Concomitant infection of Neospora caninum and Bovine Herpesvirus type 5 in spontaneous bovine abortions / Infecção simultânea de Neospora caninum e Herpesvirus bovino tipo 5 em casos espontâneos de aborto bovino

Bovine Herpesvirus type 5 (BoHV-5) has not been conclusively demonstrated to cause bovine abortion. Brain lesions produced by Neospora caninum and Bovine Herpesvirus type 1 (BoHV-1) exhibit common features. Therefore, careful microscopic evaluation and additional diagnostic procedures are required to achieve an accurate final etiological diagnosis. The aim of the present work was to investigate the occurrence of infections due to BoHV-1, BoHV-5 and N. caninum in 68 cases of spontaneous bovine abortions which showed microscopic lesions in the fetal central nervous system. This study allowed the identification of 4 (5.9%) fetuses with dual infection by BoHV-5 and N. caninum and 33 (48.5%) cases in which N. caninum was the sole pathogen identified. All cases were negative to BoHV-1. The results of this study provide evidence that dual infection by BoHV-5 and N. caninum occur during pregnancy in cattle; however, the role of BoHV-5 as a primary cause of bovine abortion needs further research. Molecular diagnosis of BoHV-5 and N. caninum confirmed the importance of applying complementary assays to improve the sensitivity of diagnosing bovine abortion.

Não está demonstrado até ao momento, que o Herpesvírus bovino tipo 5 (BoHV-5) seja um agente causal de aborto bovino. Uma vez que as lesões cerebrais tanto de Neospora caninum como de Herpesvírus bovino tipo 1(BoHV-1) têm características similares, é necessária uma avaliação microscópica cuidadosa, bem como exames laboratoriais adicionais, para obter um diagnóstico final preciso. O objetivo do presente trabalho foi investigar a presença de infeções por BoHV-1, BoHV-5 e N. caninum em 68 casos de aborto espontâneo, nos quais se verificaram lesões microscópicas no sistema nervoso central. Foram encontrados 4 (5,9%) fetos com infeção simultânea de BoHV-5 e N. caninum e 33 (48,5%) casos com infeção exclusiva de N. caninum. Todos os casos foram negativos a BoHV-1. Os resultados deste estudo demonstram que a infeção dual por BoHV-5 y N. caninum está presente durante a gestçao dos bovinos. Apesar disso, o papel de BoHV-5 como agente primário causal de aborto, carece de mais investigaçao. O diagnóstico molecular de BoHV-5 e N. caninum confirmou a importância de se aplicar ensaios complementares para melhorar a sensibilidade do diagnóstico de aborto bovino.

Safety and efficacy of an E2 glycoprotein subunit vaccine produced in mammalian cells to prevent experimental infection with bovine viral diarrhoea virus in cattle.

Bovine viral diarrhea (BVD) infection caused by bovine viral diarrhea virus (BVDV), a Pestivirus of the Flaviviridae family, is an important cause of morbidity, mortality and economical losses in cattle worldwide. E2 protein is the major glycoprotein of BVDV envelope and the main target for neutralising antibodies (NAbs). Different studies on protection against BVDV infection have focused on E2, supporting its putative use in subunit vaccines. A truncated version of type 1a BVDV E2 (tE2) expressed in mammalian cells was used to formulate an experimental oleous monovalent vaccine. Immunogenicity was studied through immunisation of guinea pigs and followed by trials in cattle. Calves of 8-12 months were vaccinated, twice with a 4 week interval, with either a tE2 subunit vaccine (n = 8), a whole virus inactivated vaccine (n = 8) or left untreated as negative control group (n = 8). Four weeks after the last immunisation the animals were experimentally challenged intranasally with a non-cythopathic BVDV strain. Following challenge, BVDV was isolated from all unvaccinated animals, while 6 out of 8 animals vaccinated with tE2 showed complete virological protection indicating that the tE2 vaccine presented a similar performance to a satisfactory whole virus inactivated vaccine.

Occurrence of bovine herpesvirus type 4 DNA in Argentinean Holstein cattle from Santiago del Estero, Argentina / Ocorrência de DNA de herpesvírus bovino tipo 4 em gado Holstein argentino de Santiago del stero, Argentina

and from cattle with a variety of clinical signs. The pathogenic role of BoHV-4 remains unclear and it is unknown whether the virus acts as a primary pathogen or whether it facilitates secondary infections After natural or experimental infections, BoHV-4 can establish latency, mainly in cells of the monocyte/macrophage linage. Latent virus can be reactivated after glucocorticoid treatment or by stress factors. In 2007, BoHV-4 was isolated for the first time in Argentina, from samples of bovine abortions. In the present study, we used viral isolation, nested PCR and restriction endonuclease analysis (REA) to investigate the presence of BoHV-4 in bovine leukocytes from a single herd of dairy cattle with reproductive problems. In this work, we demonstrated that BoHV-4 genome is present in the leukocytes of a high proportion (63.4%) of animals, probably in a latent or persistent state. BoHV-4 was isolated from one out of eleven peripheral blood leukocyte (PBL) samples. By REA we demonstrated the existence of genomic variation among the strains circulating in this particular herd. Furthermore, all PBL samples evaluated in this study differed from the American prototype strain, DN 599. Overall, this work demonstrated that BoHV-4 is present in the leukocyte fraction of dairy cattle and that viral strains present in this herd are genetically divergent. Although BoHV-4 was detected in a herd with a background of reproductive disorders, it is not possible to conclude that the virus is the primary responsible for these conditions.

O herpesvírus bovino tipo 4 (BoHV-4) é um gama-herpesvírus que foi isolado de animais aparentemente saudáveis e de gado com uma variedade de sinais clínicos. O papel patogênico do BoHV-4 ainda não está claro e não se sabe se o vírus age como um patógeno primário ou se facilita infecções secundárias. Depois de infecções naturais ou experimentais, BoHV-4 pode estabelecer latência, principalmente nas células dos linhagens de monócitos/macrófagos. O vírus latente pode ser reativado após o uso de glicocorticóides ou por fatores de estresse. Em 2007, o BoHV-4 foi isolado pela primeira vez na Argentina, a partir de amostras de abortos bovinos. No presente estudo, utilizou-se o isolamento viral, nested PCR e análise com endonucleases de restrição (REA) para investigar a presença de BoHV4 em leucócitos de bovinos provenientes de um único rebanho de gado leiteiro com problemas reprodutivos. Neste trabalho, demonstramos que o genoma do BoHV-4 está presente nos leucócitos em uma elevada proporção (63,4%) dos animais, provavelmente em um estado latente ou persistente. BoHV-4 foi isolado de uma de cada onze amostras de leucócitos no sangue periférico (PBL). Por REA nós demonstramos a existência de variações genômicas entre as estirpes circulantes deste rebanho particular. Além disso, todas as amostras de PBL avaliados neste estudo diferiram da estirpe protótipo Americano, DN 599. Em geral, este estudo demonstrou que o BoHV-4 está presente na fração leucocitária do gado leiteiro e que as estirpes virais presentes neste rebanho são geneticamente divergentes. Embora que BoHV-4 foi detectado em um rebanho com história de distúrbios reprodutivos, não é possível concluir que o vírus é o principal responsável por estas condições.

Bovine viral diarrhea virus genomic associations in mucosal disease, enteritis and generalized dermatitis outbreaks in Argentina.

The objective of the present work is the description outbreaks caused by bovine viral diarrhea virus (BVDV) in commercial beef cattle ranches in Argentina. Genetic affiliation and their association with the clinical manifestation were carried out with five BVDV isolates from an outbreak of mucosal disease (MD) (Outbreak #1), acute enteritis (Outbreaks #2 and #3) and generalized dermatitis (Outbreaks #4 and #5). Upon genetic analysis CP BVDV isolate of Outbreak #1 clustered to closely to BVDV Oregon (Genotype 1). BVDV isolates from the outbreaks of generalized dermatitis (Outbreaks #4 and #5) were located close to BVDV Osloss within Genotype 1. The identification by immunohistochemistry of BVDV in exudative dermatitis indicates the epithelial cell tropism of the virus. Phylogenic characterization of BVDV from Outbreaks #2 and #3 locate them as BVDV-2. 5'UTR sequence of these viruses revealed a homology of 88 and 90% to BVDV-890 (Genotype 2) and a 77 and 75% to BVDV-SD1 (Genotype 1), respectively. The association of BVDV-2 with severe disease indicates the presence of highly virulent strains. Data from natural outbreaks where BVDV-1 and BVDV-2 were isolated revealed that pathology overlaps and not clearly allows the differentiation between genotypes based on gross or microscopic lesions. Thus, for a definitive diagnosis, further virology and molecular studies are necessary. Additionally, the results of this work focused on the origin and consequences of genetic variations of BVDV with regard to pathogenesis and suggest the association between genotype and a defined clinical syndrome.

Seroepidemiology of beef and dairy herds and fetal study of Neospora caninum in Argentina.

The purpose of the present work was to study the epidemiology of Neospora caninum in beef and dairy herds in the Humid Pampas of Argentina. The seroprevalence of N. caninum was evaluated in 2414 serum samples of cows from beef and dairy farms. An indirect fluorescent antibody test (IFAT) was used to determine specific antibodies. The sera was screened at a dilution >or=1:200 and >or=1:600 in cows with reproductive disease antecedents and without them, respectively. Cows without history of reproductive diseases from nine beef and fifteen dairy farms were grouped according to the percentage (> or or