RESUMO
Bovine viral diarrhea virus (BVDV) infection has a significant economic impact on beef and dairy industries worldwide. Fetal infection with a non-cytopathic strain may lead to the birth of persistently infected (PI) offspring, which is the main event in the epidemiological chain of BVDV infection. This report describes the birth of 99 BVDV-PI heifer calves within 52 days of birth in a regular BVDV-vaccinated Brazilian dairy cattle herd and the subgenotypes of the infecting field strains. This study was conducted in a high-yielding open dairy cattle herd that frequently acquired heifers from neighboring areas for replacement. The farm monitors the birth of PI calves by screening all calves born using an ELISA (IDEXX) for BVDV antigen detection. All calves aged 1-7 days were evaluated. For positive and suspected results, the ELISA was repeated when the calves were close to one month old. A total of 294 heifer calves were evaluated between February and March 2021. Of these, 99 (33.7 %) had positive ELISA results and were considered PI calves. To evaluate the predominant BVDV species and subgenotypes in this outbreak, whole blood samples were collected from 31 calves born during the study period. All samples were submitted to the RT-PCR assay for the partial amplification of the BVDV 5'-UTR region, and these amplicons were subjected to nucleotide sequencing. Phylogenetic analysis identified BVDV-1b and BVDV-1d in 16 and 13 heifer calves, respectively. In two calves, it was not possible to determine the BVDV-1 subgenotype. Detection of PI animals and monitoring of circulating BVDV subgenotype strains are central to disease control. This study shows that regular BVDV vaccination alone may be insufficient to prevent BVDV infection in high-yielding open dairy cattle herds. Other biosecurity measures must be adopted to avoid the purchase of cattle with acute infections by BVDV or BVDV-PI, which can cause a break in the health profile of the herd and economic losses.
Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina , Vírus da Diarreia Viral Bovina Tipo 1 , Vírus da Diarreia Viral Bovina , Surtos de Doenças , Filogenia , Animais , Bovinos , Doença das Mucosas por Vírus da Diarreia Viral Bovina/virologia , Doença das Mucosas por Vírus da Diarreia Viral Bovina/epidemiologia , Doença das Mucosas por Vírus da Diarreia Viral Bovina/prevenção & controle , Surtos de Doenças/veterinária , Feminino , Vírus da Diarreia Viral Bovina Tipo 1/genética , Vírus da Diarreia Viral Bovina Tipo 1/classificação , Vírus da Diarreia Viral Bovina Tipo 1/isolamento & purificação , Vírus da Diarreia Viral Bovina Tipo 1/imunologia , Brasil/epidemiologia , Vírus da Diarreia Viral Bovina/genética , Vírus da Diarreia Viral Bovina/classificação , Vírus da Diarreia Viral Bovina/isolamento & purificação , Vírus da Diarreia Viral Bovina/imunologia , Genótipo , Vacinas Virais/imunologia , Ensaio de Imunoadsorção Enzimática , Indústria de Laticínios , Vacinação/veterinária , Anticorpos Antivirais/sangueRESUMO
The envelope glycoprotein E2 of pestiviruses is a major target for neutralizing antibodies. In this study, we analyzed the E2 DA domain of 43 pestiviruses from Southern Brazil. The isolates were identified as Bovine viral diarrhea virus (BVDV) subtypes 1a and 1b or BVDV-2b. Compared to reference strains, the BVDV-1 and -2 isolates had four and two mutations in the DA domain, respectively. All BVDV-2 isolates had a deletion of residues 724 and 725. All mutated amino acids in the BVDV isolates had the same aa substitution, and all were in previously identified antibody binding sites. It is possible that an immunity-mediated selection is acting on the pestiviruses circulating in Southern Brazil.
Assuntos
Vírus da Diarreia Viral Bovina/genética , Vírus da Diarreia Viral Bovina/isolamento & purificação , Proteínas do Envelope Viral/genética , Animais , Antígenos Virais/genética , Sítios de Ligação de Anticorpos/genética , Doença das Mucosas por Vírus da Diarreia Viral Bovina/epidemiologia , Doença das Mucosas por Vírus da Diarreia Viral Bovina/virologia , Brasil/epidemiologia , Bovinos , Vírus da Diarreia Viral Bovina/classificação , Vírus da Diarreia Viral Bovina/imunologia , Mutação , Filogenia , RNA Viral/genética , Proteínas do Envelope Viral/imunologiaRESUMO
Bovine viral diarrhea (BVD) is a major worldwide disease with negative economic impact on cattle production. Successful control programs of BVD require the identification and culling of persistently infected (PI) animals with bovine viral diarrhea virus (BVDV). A variety of diagnostic tests are available to detect BVDV, but no comparison has been performed among those tests in Argentina. Sera collected from 2864 cattle, belonging to 55 herds from three Argentinean provinces, were analyzed by nested RT-PCR (RT-nPCR) to detect BVDV for diagnostic purposes. Additionally, this study evaluated the agreement of the RT-nPCR along with virus isolation, antigen-capture ELISA, and real-time RT-PCR for BVDV detection in archived bovine serum samples (n = 90). The RT-nPCR was useful for BVDV detection in pooled and individual serum samples. BVDV was detected in 1% (29/2864) of the cattle and in 20% (11/55) of the herds. The proportion of BVDV-positive sera was not statistically different among the tests. In addition, comparisons showed high agreement levels, with the highest values between both RT-PCR protocols. The frequency of BVDV infection at individual and herd level was lower than the reported values worldwide. Since follow-up testing was not performed, the frequency of PI cattle was unknown. Also, this study demonstrated that the four diagnostic tests can be used reliably for BVDV identification in individual serum samples. Further epidemiologically designed studies that address prevalence, risk factors, and economic impact of BVDV in Argentina will be necessary to implement effective control programs.
Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina/sangue , Doença das Mucosas por Vírus da Diarreia Viral Bovina/diagnóstico , Vírus da Diarreia Viral Bovina/imunologia , Técnicas de Diagnóstico Molecular/normas , Técnicas de Diagnóstico Molecular/veterinária , Testes Sorológicos/normas , Testes Sorológicos/veterinária , Animais , Argentina , Bovinos , Vírus da Diarreia Viral Bovina/genética , Vírus da Diarreia Viral Bovina/isolamento & purificação , Limite de Detecção , Técnicas de Diagnóstico Molecular/métodos , Testes Sorológicos/métodos , SoroRESUMO
In-vitro fertilization is a routine livestock-breeding technique widely used around the world. Several studies have reported the interaction of bovine viral-diarrhea virus (BVDV) with gametes and in-vitro-produced (IVP) bovine embryos. Since, gene expression in BVDV-infected IVP bovine embryos is scarcely addressed. The aim of this work was to evaluate the differential expression of genes involved in immune and inflammatory response. Groups of 20-25 embryos on Day 6 (morula stage) were exposed (infected) or not (control) to an NCP-BVDV strain in SOF medium. After 24 h, embryos that reached expanded blastocyst stage were washed. Total RNA of each embryo group was extracted to determine the transcription levels of 9 specific transcripts related with antiviral and inflammatory response by SYBR Green real time quantitative (RT-qPCR). Culture media and an aliquot of the last embryos wash on Day 7 were analyzed by titration and virus isolation, respectively. A conventional PCR confirmed BVDV presence in IVP embryos. A significantly higher expression of interferon-α was observed in blastocysts exposed to NCP-BVDV compared to the controls (p < 0.05). In this study, the upregulation of INFα and TLR7 genes involved in inflammatory and immune response in BVDV-infected IVP bovine embryos is a new finding in this field. This differential expression suggest that embryonic cells could function in a manner like immune cells by recognizing and responding early to interaction with viral pathogens. These results provide new insights into the action of BVDV on the complex molecular pathways controlling bovine early embryonic development.
Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina , Bovinos , Vírus da Diarreia Viral Bovina/imunologia , Desenvolvimento Embrionário/imunologia , Expressão Gênica/imunologia , Interferon-alfa , Animais , Doença das Mucosas por Vírus da Diarreia Viral Bovina/embriologia , Doença das Mucosas por Vírus da Diarreia Viral Bovina/imunologia , Doença das Mucosas por Vírus da Diarreia Viral Bovina/virologia , Bovinos/embriologia , Bovinos/imunologia , Vírus da Diarreia Viral Bovina/isolamento & purificação , Embrião de Mamíferos/imunologia , Embrião de Mamíferos/virologia , Feminino , Fertilização in vitro , Interferon-alfa/imunologia , Receptor 7 Toll-Like/imunologiaRESUMO
Interferon lambda (IFN-λ) plays an important role in inducing an antiviral state in mucosal surfaces and has been used as an effective biotherapeutic against several viral diseases. Here we performed a proof of concept study on the activity of a biologically active recombinant bovine IFN-λ (rIFN-λ) produced in eukaryotic cells against Bovine Viral Diarrhea Virus (BVDV) in cattle. We first confirmed the lack of toxicity of different concentrations of rIFN-λ in bovine peripheral blood cells and the safety of its subcutaneous application in calves in doses up to 12 IU/kg. The antiviral activity of the rIFN-λ against BVDV was assessed in calves that were inoculated with 6 IU/kg of rIFN-λ (n = 4) or mock-treated (n = 2) two days before and after challenge with a BVDV type-2 non-cytopathic strain. Mock-treated animals developed respiratory disease, shedded the virus from 4 to 7 days post-infection (dpi) and had viremia between 4 and 14 dpi. Conversely, calves treated with rIFN-λ did not develop clinical symptoms. The virus was not found in nasal secretions or sera. Only one animal had a positive viral RNA detection in serum at 7 dpi. All infected animals treated with rIFN-λ increased systemic type-I IFNs levels at 4 dpi. The antiviral treatment induced an earlier onset of the anti-BVDV neutralizing antibodies. Altogether, these results constitute the proof-of-principle of bovine IFN-λ as an antiviral biotherapeutic to protect cattle against the clinical disease caused by BVDV.
Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina/imunologia , Doença das Mucosas por Vírus da Diarreia Viral Bovina/prevenção & controle , Doenças dos Bovinos/prevenção & controle , Vírus da Diarreia Viral Bovina/imunologia , Diarreia/veterinária , Imunização Passiva , Interferons/administração & dosagem , Fatores Etários , Animais , Bovinos , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/virologia , Diarreia/prevenção & controle , Diarreia/virologia , Vírus da Diarreia Viral Bovina Tipo 1/imunologia , Vírus da Diarreia Viral Bovina Tipo 2/imunologia , Feminino , Imunização Passiva/veterinária , Interferons/classificação , Interferons/genética , Interferons/imunologia , Estudo de Prova de Conceito , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/imunologia , Eliminação de Partículas ViraisRESUMO
Bovine viral diarrhea virus (BVDV) is a major pathogen worldwide, causing significant economic losses to the livestock sector. In Uruguay, BVDV seroprevalence at the farm level is >80%. In this work, 2546 serum, blood or tissue samples collected from animals suspected of being affected by BVD between 2015 and 2017 were analyzed by reverse transcription PCR and sequencing. Analysis of the BVDV genomic regions 5'UTR/Npro, Npro and E2 revealed that BVDV-1a, 1i and 2b circulate in the country, with BVDV-1a being the most prevalent subtype. Population dynamics studies revealed that BVDV-1a has been circulating in our herds since ~1990. This subtype began to spread and evolve, accumulating point mutations at a rate of 3.48 × 10-3 substitutions/site/year, acquiring specific genetic characteristics that gave rise to two local genetic lineages of BVDV-1a. These lineages are divergent from those circulating worldwide, as well as the vaccine strain currently used in Uruguay. The most notable differences between field and vaccine strains were found in the E2 glycoprotein, suggesting that the amino acid substitutions could result in failure of cross-protection/neutralization after vaccination. This is the first study that compares Uruguayan BVDV field and vaccine strains with other BVDV strains from throughout the world. The results obtained in this study will be very useful for developing a suitable immunization program for BVDV in Uruguay by identifying local field strains as candidates for vaccine development.
Assuntos
Vírus da Diarreia Viral Bovina/classificação , Mutação Puntual , Análise de Sequência de RNA/métodos , Substituição de Aminoácidos , Animais , Bovinos , Vírus da Diarreia Viral Bovina/genética , Vírus da Diarreia Viral Bovina/imunologia , Evolução Molecular , Filogenia , Estudos Soroepidemiológicos , Uruguai , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/imunologia , Vacinas Virais/imunologiaRESUMO
This is a cross-sectional study to assess the presence of antibodies in ruminants against selected pathogens associated with reproductive disorders in cattle in four Brazilian states, including the zoonotic agent Coxiella burnetii. The used tests were Virus Neutralization Assay for IBR and BVD, Microscopic Agglutination Test for Leptospira spp., Indirect Fluorescent Antibody Test (IFAT) for C. burnetii and Toxoplasma gondii, and Enzyme-Linked Immunosorbent Assay for Neospora caninum and Trypanosoma vivax. Seropositivity for C. burnetii was 13.7% with titers from 128 to 131,072; 57.8% for BoHV-1, with titers between 2 and 1,024; 47.1% for BVDV-1a, with titers from 10 to 5,120; 89.2% for N. caninum; 50% for T. vivax; and 52.0% for Leptospira spp., with titers between 100 to 800 (the following serovars were found: Tarassovi, Grippotyphosa, Canicola, Copenhageni, Wolffi, Hardjo, Pomona and Icterohaemorrhagiae); 19.6% for T. gondii with titer of 40. This is the first study that has identified C. burnetii in cattle associated with BoHV and BVDV, N. caninum, Leptospira spp., T. gondii and T. vivax. Thus, future studies should be conducted to investigate how widespread this pathogen is in Brazilian cattle herds.
Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina/complicações , Doenças dos Bovinos/epidemiologia , Coccidiose/veterinária , Leptospirose/veterinária , Febre Q/veterinária , Toxoplasmose Animal/complicações , Tripanossomíase Africana/veterinária , Aborto Animal , Testes de Aglutinação , Animais , Doença das Mucosas por Vírus da Diarreia Viral Bovina/diagnóstico , Doença das Mucosas por Vírus da Diarreia Viral Bovina/epidemiologia , Brasil/epidemiologia , Bovinos , Doenças dos Bovinos/microbiologia , Doenças dos Bovinos/parasitologia , Doenças dos Bovinos/virologia , Coccidiose/complicações , Coccidiose/diagnóstico , Coccidiose/epidemiologia , Coxiella burnetii/imunologia , Estudos Transversais , Vírus da Diarreia Viral Bovina/imunologia , Endometrite/etiologia , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Técnica Indireta de Fluorescência para Anticorpo/veterinária , Infertilidade Feminina/etiologia , Leptospira/imunologia , Leptospirose/complicações , Leptospirose/diagnóstico , Leptospirose/epidemiologia , Neospora/imunologia , Febre Q/complicações , Febre Q/diagnóstico , Febre Q/epidemiologia , Estudos Soroepidemiológicos , Toxoplasma/imunologia , Toxoplasmose Animal/diagnóstico , Trypanosoma vivax/imunologia , Tripanossomíase Africana/complicações , Tripanossomíase Africana/diagnóstico , Tripanossomíase Africana/epidemiologiaRESUMO
Abstract This is a cross-sectional study to assess the presence of antibodies in ruminants against selected pathogens associated with reproductive disorders in cattle in four Brazilian states, including the zoonotic agent Coxiella burnetii. The used tests were Virus Neutralization Assay for IBR and BVD, Microscopic Agglutination Test for Leptospira spp., Indirect Fluorescent Antibody Test (IFAT) for C. burnetii and Toxoplasma gondii, and Enzyme-Linked Immunosorbent Assay for Neospora caninum and Trypanosoma vivax. Seropositivity for C. burnetii was 13.7% with titers from 128 to 131,072; 57.8% for BoHV-1, with titers between 2 and 1,024; 47.1% for BVDV-1a, with titers from 10 to 5,120; 89.2% for N. caninum; 50% for T. vivax; and 52.0% for Leptospira spp., with titers between 100 to 800 (the following serovars were found: Tarassovi, Grippotyphosa, Canicola, Copenhageni, Wolffi, Hardjo, Pomona and Icterohaemorrhagiae); 19.6% for T. gondii with titer of 40. This is the first study that has identified C. burnetii in cattle associated with BoHV and BVDV, N. caninum, Leptospira spp., T. gondii and T. vivax. Thus, future studies should be conducted to investigate how widespread this pathogen is in Brazilian cattle herds.
Resumo Este é um estudo transversal para avaliar a presença de anticorpos em ruminantes contra patógenos selecionados e associados a distúrbios reprodutivos em bovinos de quatro estados brasileiros, incluindo o agente zoonótico Coxiella burnetii. Os testes utilizados foram Teste de Vírus-Neutralização para BoHV e BVDV, teste de Aglutinação Microscópica para Leptospira spp., Reação de Imunofluorescência Indireta for C. burnetii e Toxoplasma gondii, e Ensaio de Imunoabsorção Enzimática para Neospora caninum e Trypanosoma vivax. A soropositividade para C. burnetii foi de 13,7% com títulos de 128 a 131.072; 57,8% para BoHV-1, com títulos entre 2 a 1.024; 47,1% para BVDV-1a, com títulos de 10 a 5.120; 89,2% para N. caninum; 50% para T. vivax; e 52,0% para Leptospira spp., com títulos entre 100 a 800 (sorovares encontrados: Tarassovi, Grippotyphosa, Canicola, Copenhageni, Wolffi, Hardjo, Pomona e Icterohaemorrhagiae) 19,6% para T. gondii com título de 40. Este é o primeiro estudo que evidencia a participação de C. burnetii em bovinos associada ao Vírus da Rinotraqueíte bovina infecciosa e da diarreia viral bovina, N. caninum, Leptospira spp., T. gondii e T. vivax em bovinos. Desta forma, futuros estudos devem ser conduzidos a fim de investigar o quão disseminado se encontra este patógeno em rebanhos bovinos brasileiros.
Assuntos
Animais , Feminino , Bovinos , Febre Q/veterinária , Tripanossomíase Africana/veterinária , Doença das Mucosas por Vírus da Diarreia Viral Bovina/complicações , Doenças dos Bovinos/epidemiologia , Toxoplasmose Animal/complicações , Coccidiose/veterinária , Leptospirose/veterinária , Febre Q/complicações , Febre Q/diagnóstico , Febre Q/epidemiologia , Toxoplasma/imunologia , Tripanossomíase Africana/complicações , Tripanossomíase Africana/diagnóstico , Tripanossomíase Africana/epidemiologia , Doença das Mucosas por Vírus da Diarreia Viral Bovina/diagnóstico , Doença das Mucosas por Vírus da Diarreia Viral Bovina/epidemiologia , Brasil/epidemiologia , Testes de Aglutinação , Ensaio de Imunoadsorção Enzimática/veterinária , Doenças dos Bovinos/microbiologia , Doenças dos Bovinos/parasitologia , Doenças dos Bovinos/virologia , Estudos Soroepidemiológicos , Toxoplasmose Animal/diagnóstico , Estudos Transversais , Trypanosoma vivax , Coxiella burnetii/imunologia , Coccidiose/complicações , Coccidiose/diagnóstico , Coccidiose/epidemiologia , Vírus da Diarreia Viral Bovina/imunologia , Neospora/imunologia , Técnica Indireta de Fluorescência para Anticorpo/veterinária , Aborto Animal , Endometrite/etiologia , Infertilidade Feminina/etiologia , Leptospira/imunologia , Leptospirose/complicações , Leptospirose/diagnóstico , Leptospirose/epidemiologiaRESUMO
Pestiviruses including Bovine viral diarrhea virus type 1 (BVDV-1), BVDV-2 and Border disease virus (BDV) have been reported in both sheep and cattle populations, together with the HoBi-like, an emerging group of pestiviruses. Pestivirus control programs in the United States have focused on the control of BVDV-1 and 2. The incidence of pestivirus infection in sheep in the United States and the risk of transmission between cattle and sheep populations are unknown. The aim of this study was to perform serological surveillance for pestivirus exposure in sheep from an important sheep producing state in the Unites States, Wyoming. For this, sera from 500 sheep, collected across the state of Wyoming (US) in 2015-2016, were examined by comparative virus neutralization assay against four species/proposed species of pestiviruses: BVDV-1, BVDV-2, BDV and HoBi-like virus. Rates of exposure varied between geographic regions within the state. The overall pestivirus prevalence of antibodies was 5.6%. Antibodies were most frequently detected against BVDV-1 (4%), and the highest antibody titers were also against BVDV-1. Data from this study highlights understanding of the dynamics of sheep pestivirus exposure, consideration of reference strains used for VN assays, transmission patterns, and potential vaccination history should be taken into account in implementation of control measures against pestiviruses in sheep and for successful BVDV control programs in cattle.
Assuntos
Anticorpos Antivirais/sangue , Infecções por Pestivirus/veterinária , Pestivirus/imunologia , Ovinos/imunologia , Animais , Animais Domésticos/imunologia , Animais Domésticos/virologia , Bovinos/virologia , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/transmissão , Doenças dos Bovinos/virologia , Vírus da Diarreia Viral Bovina Tipo 1/imunologia , Vírus da Diarreia Viral Bovina Tipo 2/imunologia , Vírus da Diarreia Viral Bovina/imunologia , Testes de Neutralização , Pestivirus/classificação , Pestivirus/genética , Infecções por Pestivirus/epidemiologia , Infecções por Pestivirus/imunologia , Infecções por Pestivirus/transmissão , Filogenia , Estudos Soroepidemiológicos , Ovinos/virologia , Inquéritos e Questionários , Wyoming/epidemiologiaRESUMO
Hobi-like viruses comprise an unclassified group of bovine pestiviruses related to bovine viral diarrhea virus 1 (BVDV-1) and 2 (BVDV-2). These viruses were originally identified in fetal bovine serum from Brazilian origin and, subsequently, isolated from diseased animals in several countries. Herein we performed an antigenic characterization of eight Brazilian HoBi-like viruses isolated from persistently infected (PI) animals and from gastroenteric disease (2007-2015). Phylogenetic analysis based on the 5' unstranslated region (UTR) clustered these viruses with other HoBi-like viruses from European and Asiatic origin. Monoclonal antibody (MAb) binding indicated variability in the Hobi-like virus glycoprotein E2 and significant differences from the homologous BVDV-1 and BVDV-2 glycoprotein. Analysis of antigenic relatedness based on virus-neutralizing titers using virus-specific antisera revealed that HoBi-like viruses are antigenically very different from BVDV-1 and, to a lesser extent, from BVDV-2. Cross-neutralizing assays between pairs of HoBi-like viruses and their respective antisera indicated the existence of antigenic variability among these viruses, even for viruses isolated from the same herd in different occasions. Moreover, the identification of a HoBi-like isolate with low antigenic similarity with the other isolates indicates the potential existence of antigenic subgroups among HoBi-like virus isolates. Finally, sera of lambs immunized with commercial BVDV vaccines showed low or undetectable neutralizing activity against HoBi-like isolates. These results indicate significant antigenic differences between BVDV genotypes and Brazilian HoBi-like viruses and the existence of antigenic variability within this atypical group of pestiviruses. These findings extend the knowledge about the antigenic diversity of HoBi-like viruses and reinforce the need for their inclusion in current BVDV vaccines.