RESUMO
Hobi-like viruses (HobiPeV) comprise a novel, recently classified species of bovine pestiviruses, originally identified in commercial fetal bovine serum of Brazilian origin and, subsequently, isolated from diseased animals in several countries. Although frequently isolated from clinical cases, most HobiPeV isolates failed to reproduce overt disease in cattle upon experimental inoculation. Herein, we describe the outcome of experimental infection of four to six months-old seronegative calves with two Brazilian HobiPeV isolates. Calves inoculated intranasally with isolate SV478/07 developed viremia between days 2 and 9 post-inoculation (pi) and shed virus in nasal secretions up to day 11pi. These animals presented hyperthermia (day 7 to 10-11 pi) and lymphopenia from days 4 to 8pi. Clinically, all four calves developed varied degrees of apathy, anorexia, mild to moderate respiratory signs (nasal secretion, hyperemia), ocular discharge and pasty diarrhea in the days following virus inoculation. In contrast, calves inoculated with isolate SV757/15 presented only hyperthermia (days 3 to 10-11 pi) and lymphopenia (days 4-8 pi), without other apparent clinical signs. In these animals, viremia was detected up to day 9 pi and virus shedding in nasal secretions lasted up to day 12-14 pi. Both groups seroconverted to the inoculated viruses, developing virus neutralizing (VN) titers from 320 to 5120â¯at day 28pi. These results extend previous findings that experimental infections of calves with HobiPeV are predominantly mild, yet they also indicate that field isolates may differ in their ability to cause disease in susceptible animals.
Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina/virologia , Doenças dos Bovinos/virologia , Bovinos/virologia , Vírus da Diarreia Viral Bovina/classificação , Vírus da Diarreia Viral Bovina/patogenicidade , Febre/virologia , Linfopenia/virologia , Infecções por Pestivirus/virologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Temperatura Corporal , Doença das Mucosas por Vírus da Diarreia Viral Bovina/imunologia , Doença das Mucosas por Vírus da Diarreia Viral Bovina/fisiopatologia , Brasil , Vírus da Diarreia Viral Bovina/isolamento & purificação , Modelos Animais de Doenças , Masculino , Infecções por Pestivirus/imunologia , Infecções por Pestivirus/veterinária , Fatores de Tempo , Carga Viral , Viremia/virologia , Eliminação de Partículas ViraisRESUMO
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.
Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/sangue , Variação Antigênica , Doenças dos Bovinos/imunologia , Infecções por Pestivirus/veterinária , Pestivirus/imunologia , Animais , Bovinos , Doenças dos Bovinos/virologia , Vírus da Diarreia Viral Bovina Tipo 1/genética , Vírus da Diarreia Viral Bovina Tipo 1/imunologia , Vírus da Diarreia Viral Bovina Tipo 1/isolamento & purificação , Vírus da Diarreia Viral Bovina Tipo 2/genética , Vírus da Diarreia Viral Bovina Tipo 2/imunologia , Vírus da Diarreia Viral Bovina Tipo 2/isolamento & purificação , Vírus da Diarreia Viral Bovina/genética , Vírus da Diarreia Viral Bovina/imunologia , Vírus da Diarreia Viral Bovina/isolamento & purificação , Imunização/veterinária , Pestivirus/genética , Pestivirus/isolamento & purificação , Infecções por Pestivirus/imunologia , Infecções por Pestivirus/virologia , Filogenia , OvinosRESUMO
The aim of this survey was to determine the prevalence of anti-pestivirus antibodies in dairy goats from the semiarid region of the Paraíba state, Northeastern Brazil, as well as to identify risk factors associated with the flock-level prevalence. A total of 1,092 dairy goats from 110 flocks randomly selected in the county of Monteiro, Paraíba state, during March 2009 to March 2010, were used. In each selected flock a epidemiological questionnaire was applied to verify the occurrence of possible factors that could be associated with the flock-level prevalence. For the serological diagnosis of Pestivirus infection the serum neutralization test, using the BVDV-1 NADL strain, was carried out. Flock-level prevalence was 6.36% (95% CI = 2.60% 12.67%) and animal-level prevalence was 0.82% (95% CI = 0.38% 1.56%). Not to perform vermifugation (odds ratio = 10.49; p = 0.035) and to perform navel cut and disinfection (odds ratio = 12.73; p = 0.034) were identified as risk factors. These results indicate viral circulation in dairy goats in the semiarid region of the Paraíba state.(AU)
O objetivo do presente trabalho foi determinar a prevalênciade anticorpos anti-pestivírus em caprinos leiteiros do semiárido do Estado da Paraíba, Nordeste do Brasil, bem como identificar fatores de risco associados à prevalência de rebanhos positivos. Foram utilizados 1.092 cabras leiteiras de 110 propriedades selecionadas aleatoriamente no Município de Monteiro, Estado da Paraíba, no período de março de 2009 a março de 2010. Em cada propriedade selecionada foi aplicado questionário epidemiológico para verificar a ocorrência de possíveis fatores associados à ocorrência da infecção. Para o diagnóstico sorológico da infecção por Pestivírus, foi utilizada a prova de soroneutralização com a estipe de BVDV-1 NADL. A prevalência de propriedades positivas foi de 6,36% (IC 95% = 2,60% 12,67%) e a prevalência de animais soropositivos foi de 0,82% (IC 95% = 0,38% 1,56%). Não realizar vermifugação (odds ratio= 10,49; p = 0,035) e realizar corte e desinfecção de umbigo (odds ratio= 12,73; p = 0,034) foram identificados como fatores de risco. Os resultados obtidos indicam a circulação viral em caprinos leiteiros do semiárido da Paraíba.(AU)
Assuntos
Animais , Feminino , Cabras/virologia , Pestivirus/isolamento & purificação , Infecções por Pestivirus/epidemiologia , Infecções por Pestivirus/imunologia , Infecções por Pestivirus/veterinária , Fatores de RiscoRESUMO
The aim of this survey was to determine the prevalence of anti-pestivirus antibodies in dairy goats from the semiarid region of the Paraíba state, Northeastern Brazil, as well as to identify risk factors associated with the flock-level prevalence. A total of 1,092 dairy goats from 110 flocks randomly selected in the county of Monteiro, Paraíba state, during March 2009 to March 2010, were used. In each selected flock a epidemiological questionnaire was applied to verify the occurrence of possible factors that could be associated with the flock-level prevalence. For the serological diagnosis of Pestivirus infection the serum neutralization test, using the BVDV-1 NADL strain, was carried out. Flock-level prevalence was 6.36% (95% CI = 2.60% 12.67%) and animal-level prevalence was 0.82% (95% CI = 0.38% 1.56%). Not to perform vermifugation (odds ratio = 10.49; p = 0.035) and to perform navel cut and disinfection (odds ratio = 12.73; p = 0.034) were identified as risk factors. These results indicate viral circulation in dairy goats in the semiarid region of the Paraíba state.
O objetivo do presente trabalho foi determinar a prevalênciade anticorpos anti-pestivírus em caprinos leiteiros do semiárido do Estado da Paraíba, Nordeste do Brasil, bem como identificar fatores de risco associados à prevalência de rebanhos positivos. Foram utilizados 1.092 cabras leiteiras de 110 propriedades selecionadas aleatoriamente no Município de Monteiro, Estado da Paraíba, no período de março de 2009 a março de 2010. Em cada propriedade selecionada foi aplicado questionário epidemiológico para verificar a ocorrência de possíveis fatores associados à ocorrência da infecção. Para o diagnóstico sorológico da infecção por Pestivírus, foi utilizada a prova de soroneutralização com a estipe de BVDV-1 NADL. A prevalência de propriedades positivas foi de 6,36% (IC 95% = 2,60% 12,67%) e a prevalência de animais soropositivos foi de 0,82% (IC 95% = 0,38% 1,56%). Não realizar vermifugação (odds ratio= 10,49; p = 0,035) e realizar corte e desinfecção de umbigo (odds ratio= 12,73; p = 0,034) foram identificados como fatores de risco. Os resultados obtidos indicam a circulação viral em caprinos leiteiros do semiárido da Paraíba.
Assuntos
Feminino , Animais , Cabras/virologia , Fatores de Risco , Infecções por Pestivirus/epidemiologia , Infecções por Pestivirus/imunologia , Infecções por Pestivirus/veterinária , Pestivirus/isolamento & purificaçãoRESUMO
The genus Pestivirus is composed of 4 important pathogens of livestock: Bovine viral diarrhea virus 1 and 2 (BVDV-1 and BVDV-2), Classical swine fever virus (CSFV), and Border disease virus of sheep (BDV). BVDV are major pathogens of cattle, and infection results in significant economic loss worldwide. A new putative pestivirus species, tentatively called "HoBi-like," "BVDV-3," or "atypical pestiviruses," was first identified in Europe in fetal bovine serum (FBS) imported from Brazil. HoBi-like viruses are related to BVDV at the genetic and antigenic levels. Further, the disease caused by these new viruses resembles clinical presentations historically associated with BVDV infection, including growth retardation, reduced milk production, respiratory disease, reduced reproductive performance, and increased mortality among young stock. Current BVDV diagnostic tests may fail to detect HoBi-like viruses or to differentiate between BVDV and HoBi-like viruses. Further, commercial tests for BVDV exposure, based on serological response, do not reliably detect HoBi-like virus exposure, and cross protection against HoBi-like viruses conferred by current BVDV vaccines is likely limited. As many HoBi-like viruses, characterized to date, were isolated from FBS originating from Brazil, it is assumed that the agent is probably widespread in Brazilian herds. Nevertheless, reports of natural infection in Southeast Asia and Europe demonstrate that these viruses are not restricted to South America. Increased demand for FBS has led to widespread distribution of FBS originating in HoBi-like virus endemic regions. The contamination of such FBS with HoBi-like viruses may lead to spread of this virus to other regions.