RESUMEN
Bovine viral diarrhea viruses (BVDV) are members of the Pestivirus genus within the family Flaviviridae. Based on antigenic and nucleotide differences, BVDV are classified into two recognized species, BVDV-1 and BVDV-2. More recently, a new putative pestivirus species, tentatively called "HoBi-like", has been associated with bovine viral diarrhea. HoBi-like viruses were first identified in fetal bovine serum (FBS) imported from Brazil. Subsequently, a number of HoBi-like viruses have been detected as contaminants in FBS or cell culture and in live ruminants. To further investigate the possible pestivirus contamination in commercially available FBS batches, 26 batches of FBS with various countries of origin, were tested in this study for the presence of bovine pestiviruses. All the 26 batches were positive by RT-PCR for at least one species of bovine pestiviruses. HoBi-like viruses were detected in 15 batches. Analysis of the 5'UTR and N(pro) sequences of 15 newly identified HoBi-like viruses combined with analysis of additional sequences from GenBank, identified 4 genetic groups tentatively named 3a-3d. The current study confirmed the presence of the emerging HoBi-like viruses in FBS products labeled with different geographic origins. This finding has obvious implications for the safety of biological products, such cell lines and vaccines.
Asunto(s)
Virus de la Diarrea Viral Bovina/genética , Sangre Fetal/virología , Animales , Bovinos , Virus de la Diarrea Viral Bovina/clasificación , Virus de la Diarrea Viral Bovina/aislamiento & purificación , FilogeniaRESUMEN
Bovine viral diarrhea viruses (BVDV) comprise a diverse group of viruses that cause disease in cattle. BVDV may establish both transient and persistent infections depending on the developmental stage of the animal at exposure. The objective was to determine whether genomic regions harboring single nucleotide polymorphisms (SNPs) could be associated with the presence or absence of persistent BVDV infection. A genome-wide association approach based on 777,000 SNP markers was used. Samples of animals identified as positive (n = 1200) or negative (n = 1200) for the presence of BVDV in skin samples (n = 1200) were used. DNA samples were combined in 24 pools (100 animals per pool). One SNP, significant at the 5 percent genome-wide level (P = 9.41 × 10(-8) ), was detected on chromosome 14, located at position 80 675 176 bp. Fifteen SNPs, residing on chromosomes 1, 2, 6, 8, 10, 15 and 18, were moderately associated (P < 1 × 10(-5) ) with persistent BVDV infection. Results show that genes harboring or neighboring significant SNPs are involved in leucopenia, signal transduction, RNA splicing and DNA methylation processes.
Asunto(s)
Diarrea Mucosa Bovina Viral/genética , Bovinos/genética , Estudio de Asociación del Genoma Completo , Animales , Virus de la Diarrea Viral Bovina , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , Incidencia , Modelos Genéticos , Polimorfismo de Nucleótido SimpleRESUMEN
The identification and elimination of persistently infected (PI) cattle are the most effective measures for controlling bovine pestiviruses, including bovine viral diarrhea virus (BVDV) and the emerging HoBi-like viruses. Here, colostrum-deprived calves persistently infected with HoBi-like pestivirus (HoBi-like PI calves) were generated and sampled (serum, buffy coat, and ear notches) on the day of birth (DOB) and weekly for 5 consecutive weeks. The samples were subjected to diagnostic tests for BVDV--two reverse transcriptase PCR (RT-PCR) assays, two commercial real-time RT quantitative PCR (RT-qPCR), two antigen capture enzyme-linked immunosorbent assays (ACE), and immunohistochemistry (IHC)--and to HoBi-like virus-specific RT-PCR and RT-qPCR assays. The rate of false negatives varied among the calves. The HoBi-like virus-specific RT-PCR detected HoBi-like virus in 83%, 75%, and 87% of the serum, buffy coat, and ear notch samples, respectively, while the HoBi-like RT-qPCR detected the virus in 83%, 96%, and 62%, respectively. In comparison, the BVDV RT-PCR test had a higher rate of false negatives in all tissue types, especially for the ear notch samples (missing detection in at least 68% of the samples). The commercial BVDV RT-qPCRs and IHC detected 100% of the ear notch samples as positive. While ACE based on the BVDV glycoprotein E(rns) detected infection in at least 87% of ear notches, no infections were detected using NS3-based ACE. The BVDV RT-qPCR, ACE, and IHC yielded higher levels of detection than the HoBi-like virus-specific assays, although the lack of differentiation between BVDV and HoBi-like viruses would make these tests of limited use for the control and/or surveillance of persistent HoBi-like virus infection. An improvement in HoBi-like virus tests is required before a reliable HoBi-like PI surveillance program can be designed.
Asunto(s)
Técnicas de Laboratorio Clínico/métodos , Pruebas Diagnósticas de Rutina/métodos , Infecciones por Pestivirus/veterinaria , Pestivirus/aislamiento & purificación , Animales , Capa Leucocitaria de la Sangre/virología , Bovinos , Oído/virología , Reacciones Falso Negativas , Inmunoensayo/métodos , Inmunohistoquímica/métodos , Técnicas de Diagnóstico Molecular/métodos , Infecciones por Pestivirus/diagnóstico , Suero/virologíaRESUMEN
Studies in young animals have shown an association between vitamin deficiencies and increased risk of infectious disease; however, there is a paucity of information regarding the effect of acute infection on the vitamin status of the vitamin-replete neonate. To characterize the effects of acute infection on vitamin D and E status of the neonate, 6 vitamin-replete preruminant Holstein bull calves were experimentally infected with bovine viral diarrhea virus (BVDV; strain BVDV2-1373). Six mock-inoculated calves served as controls. Sustained pyrexia, leukopenia, and asynchronous increases in serum haptoglobin and serum amyloid A characterized the response of calves to infection with BVDV. Infection was also associated with increased serum IFN-γ, IL-2, and IL-6 concentrations. During the last 8 d of the 14-d postinoculation period, serum 25-hydroxyvitamin D and α-tocopherol concentrations in infected calves decreased by 51 and 82%, respectively. The observed inverse association between vitamin D and E status and serum amyloid A in infected calves suggests that the infection-induced acute phase response contributed to the reduced vitamin status of these animals. Additional studies are necessary to determine if the negative effect of infection on status are unique to this specific infection model or is representative of preruminant calf's response to acute infection. Studies are also needed to characterize mechanisms underlying infection-related changes in vitamin D and E status and to determine whether additional vitamin D or E supplementation during an acute infection diminishes disease severity and duration in the young animal.
Asunto(s)
Reacción de Fase Aguda/virología , Diarrea Mucosa Bovina Viral/sangre , Deficiencia de Vitamina D/veterinaria , Vitamina D/sangre , Deficiencia de Vitamina E/veterinaria , alfa-Tocoferol/sangre , Reacción de Fase Aguda/sangre , Animales , Diarrea Mucosa Bovina Viral/complicaciones , Bovinos , Virus de la Diarrea Viral Bovina Tipo 1/aislamiento & purificación , Virus de la Diarrea Viral Bovina Tipo 2/aislamiento & purificación , Haptoglobinas/metabolismo , Interferón gamma/sangre , Interleucina-1beta/sangre , Interleucina-2/sangre , Interleucina-6/sangre , Masculino , Proteína Amiloide A Sérica/metabolismo , Deficiencia de Vitamina D/sangre , Deficiencia de Vitamina E/sangreRESUMEN
A newborn Longhorn heifer calf presented with generalized tremors, muscle fasciculations, ataxia, and nystagmus. At necropsy, no gross central nervous system lesions were observed. Histologically, the brain and spinal cord had mild to moderate diffuse microgliosis and astrocytosis, minimal nonsuppurative encephalitis, and decreased myelin staining. Ultrastructural examination revealed thinning and absence of myelin sheaths. Various cell types were immunohistochemically positive for bovine viral diarrhea virus (BVDV). Noncytopathogenic BVDV was isolated from the brain and identified as BVDV type 2 by phylogenetic analysis. BVDV-induced hypomyelination is rare and analogous to lesions in neonates infected with border disease and classical swine fever viruses. This is the first documented case of hypomyelination in a calf specifically attributed to BVDV type 2 and the first description of the ultrastructural appearance of BVDV-induced hypomyelination.
Asunto(s)
Diarrea Mucosa Bovina Viral/congénito , Virus de la Diarrea Viral Bovina Tipo 2/aislamiento & purificación , Vaina de Mielina/patología , Animales , Animales Recién Nacidos , Diarrea Mucosa Bovina Viral/complicaciones , Diarrea Mucosa Bovina Viral/patología , Bovinos , Resultado Fatal , Femenino , Inmunohistoquímica/veterinariaRESUMEN
Bovine viral diarrhea viruses (BVDV), segregated in BVDV-1 and BVDV-2 species, lead to substantial economic losses to the cattle industry worldwide. It has been hypothesized that there could be differences in level of replication, pathogenesis and tissue tropism between BVDV-1 and BVDV-2 strains. Thus, this study developed an in vitro method to evaluate virus competition between BVDV-1 and BVDV-2 strains. To this end the competitive dynamics of BVDV-1a, BVDV-1b, and BVDV-2a strains in cell cultures was evaluated by a PrimeFlow RNA assay. Similar results were observed in this study, as was observed in an earlier in vivo transmission study. Competitive exclusion was observed as the BVDV-2a strains dominated and excluded the BVDV-1a and BVDV-1b strains. The in vitro model developed can be used to identify viral variations that result in differences in frequency of subgenotypes detected in the field, vaccine failure, pathogenesis, and strain dependent variation in immune responses.
Asunto(s)
Bioensayo , Virus de la Diarrea Viral Bovina Tipo 1/genética , Virus de la Diarrea Viral Bovina Tipo 2/genética , Células Epiteliales/virología , ARN Viral/genética , Animales , Diarrea Mucosa Bovina Viral/diagnóstico , Diarrea Mucosa Bovina Viral/virología , Bovinos , Línea Celular , Coinfección , Virus de la Diarrea Viral Bovina Tipo 1/clasificación , Virus de la Diarrea Viral Bovina Tipo 1/aislamiento & purificación , Virus de la Diarrea Viral Bovina Tipo 1/metabolismo , Virus de la Diarrea Viral Bovina Tipo 2/clasificación , Virus de la Diarrea Viral Bovina Tipo 2/aislamiento & purificación , Virus de la Diarrea Viral Bovina Tipo 2/metabolismo , Perros , Células Epiteliales/patología , Femenino , Células de Riñón Canino Madin Darby , Embarazo , ARN/genética , ARN/metabolismo , Sondas ARN/genética , Sondas ARN/metabolismo , ARN Viral/metabolismo , Tropismo Viral , Replicación ViralRESUMEN
Bovine viral diarrhoea viruses (BVDV) are significant pathogens of cattle worldwide. These viruses exist in both non-cytopathic and cytopathic biotypes. Non-cytopathic BVDV can establish persistent lifelong infections in cattle and are a frequent contaminant of biological reagents such as cell cultures and foetal bovine serum. We identified commercially available bovine aortic endothelial cells (BAECs) contaminated with BVDV. In this study, to determine if BVDV alters endothelial gene transcription patterns, serial analysis of gene expression (SAGE) was used to compare gene expression profiles from uninfected and BVDV contaminated BAEC. SAGE is an open ended, quantitative method for characterizing global patterns of transcription. Comparison of expression profiles of BVDV-contaminated and noninfected cells revealed significant increases in the transcription of many genes including P-selectin, tryptophan tRNA synthetase and prostaglandin D2 synthase. These changes were validated by real-time PCR. Additionally, real-time PCR demonstrated that the response to LPS and dsRNA by contaminated cells, as well as cells acutely infected with noncytopathic BVDV, is altered. The altered response may be through the high level of expression of A20 and inhibition of activation of NF-kappaB. BAECs are commonly used as a model to study endothelial cell function in many different systems. As shown here, transcriptional and probable protein changes resulting from BVDV infection significantly alter cellular responses and may have a profound impact on experimental outcome. Transcriptomic analysis provided the initial clues leading to the characterization of this altered function.
Asunto(s)
Virus de la Diarrea Viral Bovina/fisiología , Endotelio Vascular/metabolismo , Perfilación de la Expresión Génica , Transcripción Genética , Animales , Bovinos , Células Cultivadas , Endotelio Vascular/virología , Reacción en Cadena de la PolimerasaRESUMEN
The pestiviruses bovine viral diarrhea virus 1 (BVDV-1), 2 (BVDV-2), and HoBi-like (HoBiPeV) are endemic among Brazilian cattle, the world's largest commercial bovine herd. In the last two decades (1998-2018) over 300 bovine pestiviruses have been partially or fully sequenced in Brazil, including viruses from different regions, different epidemiological backgrounds, and associated with diverse clinical presentations. Phylogenetic analysis of these viruses demonstrated a predominance of BVDV-1 (54.4%), with subgenotypes -1a (33.9% of total) and -1b (16.3%) being more frequent and subgenotypes -1d, -1e, and -1i at very low frequencies. The overall BVDV-2 frequency was 25.7% but it varied largely by region, reaching up to 48% in Southern states. BVDV-2b was the predominant subgenotype (84.8% of BVDV-2), followed by BVDV-2a (8.86%). HoBiPeV accounted for 19.9% (61/307) of the genotyped viruses and were detected at high frequency in cattle from Northeastern states. These findings demonstrate a unique mix of pestivirus species and subgenotypes, unlike that seen in Europe or North America. The design of effective diagnostic tools, vaccines, and control programs for limiting bovine pestivirus infections in Brazil must take into consideration this unique mix of viruses. This article provides a critical review of two decades of genetic identification of pestiviruses in Brazil.
Asunto(s)
Diarrea Mucosa Bovina Viral/virología , Virus de la Diarrea Viral Bovina/genética , Animales , Diarrea Mucosa Bovina Viral/epidemiología , Brasil/epidemiología , Bovinos , Virus de la Diarrea Viral Bovina/aislamiento & purificación , GenotipoRESUMEN
The genus Pestivirus within Flaviviridae is comprised of four recognized species, namely, bovine viral diarrhoea virus 1 (BVDV-1), bovine viral diarrhoea virus 2 (BVDV-2), border disease virus (BDV) and classical swine fever virus (CSFV). BDV, while primarily infecting sheep and goats, has also been reported in cattle and wild animals. Infections of sheep and goats result in economic loss due to abortions and the birth of persistently infected animals that have poor production and reduced life expectancy. In this study, we report the detection of BDV in cattle serum collected as part of pestivirus surveillance programme from six regions of Mexico, where a 67.1% of BVDV seroprevalence was calculated previously. Phylogenetic analyses based on comparison of the 5'UTR region typed the Mexican strains as BDV-1. Border disease (BD) is listed as an exotic disease in Mexico, and the origin of BDV found in these cattle is unclear. This is the first identification of BDV in Mexican cattle.
Asunto(s)
Enfermedad de la Frontera/virología , Virus de la Enfermedad de la Frontera/aislamiento & purificación , Enfermedades de los Bovinos/virología , Animales , Enfermedad de la Frontera/epidemiología , Virus de la Enfermedad de la Frontera/genética , Virus de la Enfermedad de la Frontera/inmunología , Bovinos , Enfermedades de los Bovinos/epidemiología , Femenino , México/epidemiología , Filogenia , Embarazo , ARN Viral/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria , Estudios SeroepidemiológicosRESUMEN
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.
Asunto(s)
Anticuerpos Antivirales/sangre , Infecciones por Pestivirus/veterinaria , Pestivirus/inmunología , Ovinos/inmunología , Animales , Animales Domésticos/inmunología , Animales Domésticos/virología , Bovinos/virología , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/transmisión , Enfermedades de los Bovinos/virología , Virus de la Diarrea Viral Bovina Tipo 1/inmunología , Virus de la Diarrea Viral Bovina Tipo 2/inmunología , Virus de la Diarrea Viral Bovina/inmunología , Pruebas de Neutralización , Pestivirus/clasificación , Pestivirus/genética , Infecciones por Pestivirus/epidemiología , Infecciones por Pestivirus/inmunología , Infecciones por Pestivirus/transmisión , Filogenia , Estudios Seroepidemiológicos , Ovinos/virología , Encuestas y Cuestionarios , Wyoming/epidemiologíaRESUMEN
The ruminant pestiviral species BVDV-1, BVDV-2 and BDV, along with the putative species HoBi-like, may cause substantial economic losses in cattle, sheep and goats. Brazil's large size, variable biomes and wide range of ruminant animal production within different geographic regions suggest that the presence and prevalence of ruminant pestivirus may differ by regions within Brazil. This study investigated the genetic diversity of ruminant pestiviruses and determined the frequency of active infections within two states of the Northeast Region of Brazil, Maranhão and Rio Grande do Norte. Serum samples from 16,621 cattle and 2,672 small ruminants from 569 different herds residing in this region were tested by RT-PCR followed by DNA sequencing. Seventeen positive cattle were detected (0.1%) from fifteen different herds (2.64%). All isolates were classified as HoBi-like pestiviruses based on phylogenetic analysis. All small ruminant samples tested negative. The findings presented herein suggest that the Northeast Region of Brazil has a uniquely high prevalence of HoBi-like viruses. The increasing reports of HoBi-like viruses detected in cattle in the field suggest that natural infection with these viruses may be more widespread than previously thought. The identification of HoBi-like viruses as the most prevalent type of ruminant pestivirus circulating in the Northeast Region of Brazil indicates the need for both continued monitoring and determination of the extent of economic losses associated with HoBi-like virus infections. In addition, it must be taken into account in the choice of diagnostic tests and in vaccine formulations.
Asunto(s)
Enfermedades de los Bovinos/virología , Virus de la Diarrea Viral Bovina/genética , Variación Genética , Infecciones por Pestivirus/veterinaria , Animales , Brasil/epidemiología , Bovinos , Enfermedades de los Bovinos/epidemiología , Virus de la Diarrea Viral Bovina Tipo 1/clasificación , Virus de la Diarrea Viral Bovina Tipo 1/genética , Virus de la Diarrea Viral Bovina Tipo 1/aislamiento & purificación , Virus de la Diarrea Viral Bovina Tipo 2/clasificación , Virus de la Diarrea Viral Bovina Tipo 2/genética , Virus de la Diarrea Viral Bovina Tipo 2/aislamiento & purificación , Virus de la Diarrea Viral Bovina/clasificación , Virus de la Diarrea Viral Bovina/aislamiento & purificación , Infecciones por Pestivirus/epidemiología , Infecciones por Pestivirus/virología , Filogenia , Prevalencia , Rumiantes , Análisis de Secuencia de ADN/veterinariaRESUMEN
Bovine viral diarrhea virus (BVDV), a pestivirus of the Flaviviridae family, is an economically important cattle pathogen with a worldwide distribution. Besides the segregation into two distinct species (BVDV1/BVDV2) two different biotypes, a cytopathic (cp) and a noncytopathic (ncp) biotype, are distinguished based on their behavior in epithelial cell cultures. One of the most serious forms of BVDV infection affecting immunocompetent animals of all ages is severe acute BVD (sa BVD) which is caused by highly virulent ncp BVDV2 strains. Previous studies revealed that these highly virulent ncp viruses cause cell death in a lymphoid cell line (BL3) which is not clearly associated with typical apoptotic changes (e.g. PARP cleavage) observed after infection with cp BVDV. To further characterize the underlying molecular mechanisms, we first analyzed the role of the mitochondria and caspases as key mediators of apoptosis. Compared to infection with cp BVDV2, infection with highly virulent ncp BVDV2 resulted in a delayed and less pronounced disruption of the mitochondrial transmembrane potential (DeltaPsi(m)) and a weaker activation of the caspase cascade. In contrast, infection with low virulence ncp BVDV2 showed no significant differences from the uninfected control cells. Since different pro- and anti-apoptotic cellular signaling pathways may become activated upon virus infection, we compared the effect of different BVDV2 strains on cellular signaling pathways in BL3 cells. Stress-mediated p38 MAPK phosphorylation was detected only in cells infected with cp BVDV2. Interestingly, infection with highly virulent ncp BVDV2 was found to influence the phosphoinositide 3-kinase (PI3K)-Akt pathway. This indicates that BL3 cells respond differently to infection with BVDV depending on virulence and biotype.
Asunto(s)
Virus de la Diarrea Viral Bovina Tipo 2/patogenicidad , Animales , Apoptosis , Diarrea Mucosa Bovina Viral/patología , Diarrea Mucosa Bovina Viral/fisiopatología , Diarrea Mucosa Bovina Viral/virología , Caspasas/metabolismo , Bovinos , Línea Celular , Efecto Citopatogénico Viral , Virus de la Diarrea Viral Bovina Tipo 2/clasificación , Activación Enzimática , Potencial de la Membrana Mitocondrial , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal , VirulenciaRESUMEN
In 2003 an outbreak of sudden deaths occurred in 3-4-week-old piglets on a farm in New South Wales, Australia. There was a marked increase in the birth of stillborn foetuses. Pathological changes consisted of a multifocal non-suppurative myocarditis. A viral infection was suspected but a wide range of known agents were excluded. A modified sequence independent single primer amplification (SISPA) method was used to identify a novel virus associated with this outbreak. Conserved 5'UTR motifs, the presence of a putative N(pro) coding region and limited antigenic cross-reactivity with other members of the Pestivirus genus, support the placement of this virus in the Pestivirus genus. Phylogenetic analysis of the 5'UTR, N(pro) and E2 coding regions showed this virus to be the most divergent pestivirus identified to date.
Asunto(s)
Infecciones por Pestivirus/veterinaria , Pestivirus/aislamiento & purificación , Enfermedades de los Porcinos/virología , Regiones no Traducidas 5'/genética , Animales , Antígenos Virales/inmunología , Australia , Reacciones Cruzadas , Brotes de Enfermedades , Endopeptidasas/genética , Liasa de Heparina , Miocarditis/patología , Sistemas de Lectura Abierta/genética , Pestivirus/genética , Pestivirus/inmunología , Infecciones por Pestivirus/epidemiología , Infecciones por Pestivirus/patología , Infecciones por Pestivirus/virología , Ribonucleasas/genética , Sus scrofa , Enfermedades de los Porcinos/epidemiología , Enfermedades de los Porcinos/patología , Proteínas del Envoltorio Viral/genética , Proteínas Virales/genética , DesteteRESUMEN
The ability of ruminant pestivirus including bovine viral diarrhoea virus (BVDV) and the related emerging pestivirus, HoBi-like virus, to establish persistent infection (PI) following foetal infection is central to keeping these viruses in circulation. Non-PI dams carrying BVDV PI calves develop high levels of immunity due constantly viral exposure. A study to determine whether the immunity developed following the generation of a BVDV PI is enough to prevent HoBi-like virus infection of a subsequent foetus was performed. This study consisted of nine pregnant cows, four had birthed BVDV-1 PI calves in a previous pregnancy, three cows had birthed BVDV-2 PIs and two had birthed pestivirus negative calves. From this, six pregnant cows were challenged with HoBi-like virus about day 85 of gestation (four BVDV-1 and two BVDV-2 cows) and three non-challenged cows (negative control). At the day of challenge, the serum neutralizing titres against the homologous BVDV strains of the first inoculation ranged from 1148 to 5793. At day 6 post-challenge, HoBi-like RNA was detected in the serum of all four BVDV-1 cows but not in the two BVDV-2 cows. The foetuses harvested from five of the exposed dams (three BVDV-1 and two BVDV-2 cows) at day 30 post-challenge were positive for HoBi-like virus RNA. The sixth cow, BVDV-1 cow #541, while pregnant at the time of exposure, had no foetus 30 days after exposure. Foetuses from HoBi-like virus exposed dams were significantly smaller and lighter than control foetuses. HoBi-like RNA was detected in samples of all challenged foetuses. The identification of viral RNA in the serum of 4 cows at day 6 post-challenge, as well viral RNA detection in all foetuses 30 days post-inoculation, indicates that the foetuses of dams with high antibodies titres against BVDV-1 or BVDV-2 would not be protected from challenge with a HoBi-like virus.
Asunto(s)
Diarrea Mucosa Bovina Viral/transmisión , Virus de la Diarrea Viral Bovina Tipo 1/aislamiento & purificación , Virus de la Diarrea Viral Bovina Tipo 2/aislamiento & purificación , Feto/virología , Animales , Anticuerpos Antivirales/sangre , Diarrea Mucosa Bovina Viral/virología , Bovinos , Virus de la Diarrea Viral Bovina Tipo 1/genética , Virus de la Diarrea Viral Bovina Tipo 2/genética , Femenino , Embarazo , Complicaciones Infecciosas del Embarazo/veterinaria , Complicaciones Infecciosas del Embarazo/virología , ARN Viral/genética , Suero , VacunaciónRESUMEN
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.
Asunto(s)
Anticuerpos Monoclonales/inmunología , Anticuerpos Antivirales/sangre , Variación Antigénica , Enfermedades de los Bovinos/inmunología , Infecciones por Pestivirus/veterinaria , Pestivirus/inmunología , Animales , Bovinos , Enfermedades de los Bovinos/virología , Virus de la Diarrea Viral Bovina Tipo 1/genética , Virus de la Diarrea Viral Bovina Tipo 1/inmunología , Virus de la Diarrea Viral Bovina Tipo 1/aislamiento & purificación , Virus de la Diarrea Viral Bovina Tipo 2/genética , Virus de la Diarrea Viral Bovina Tipo 2/inmunología , Virus de la Diarrea Viral Bovina Tipo 2/aislamiento & purificación , Virus de la Diarrea Viral Bovina/genética , Virus de la Diarrea Viral Bovina/inmunología , Virus de la Diarrea Viral Bovina/aislamiento & purificación , Inmunización/veterinaria , Pestivirus/genética , Pestivirus/aislamiento & purificación , Infecciones por Pestivirus/inmunología , Infecciones por Pestivirus/virología , Filogenia , OvinosRESUMEN
Pestivirus infections in ruminants result in significant economic losses worldwide. The aetiological agents are three species from the genus Pestivirus, family Flaviviridae, including bovine viral diarrhoea virus type 1 (BVDV-1), BVDV-2, border disease virus (BDV), and an atypical pestivirus named HoBi-like pestivirus. In this study, eighty-nine pestivirus isolates that were collected in Brazil between 1995 and 2014 and that originated from either cattle, fetal bovine serum (FBS) or as cell culture contaminants were genotyped based on a comparison of gene sequences from their 5' untranslated regions (5'UTR), N-terminal autoprotease (Npro ) and envelope glycoprotein 2 (E2). Of these isolates, 53.9% of the sequences were genotyped as BVDV-1, 33.7% as BVDV-2 and 12.4% as HoBi-like pestivirus. The prevalence of subgenotypes within the species was as follows: BVDV-1a (35.9%), BVDV-2b (31.4%), BVDV-1b (10.1%), BVDV-1d (6.7%), BVDV-2c (2.2%) and BVDV-1e (1.1%). BVDV-2c and BVDV-1e were detected for the first time in Brazil. This study revealed extensive genetic diversity among Brazilian pestivirus isolates, and the combination of pestiviruses that was detected is unique to Brazil. This information may serve as a foundation for designing and evaluating diagnostic tools and in the development of more effective vaccines; therefore, it may potentially contribute to pestivirus control and eradication.
Asunto(s)
Virus de la Diarrea Viral Bovina Tipo 1/genética , Virus de la Diarrea Viral Bovina Tipo 2/genética , Variación Genética , Animales , Brasil , Bovinos , FilogeniaRESUMEN
This paper demonstrates the capability of atomic force microscopy (AFM) and surface enhanced Raman spectroscopy (SERS) to function effectively as ultra-sensitive readout tools for chip-scale platforms designed for pathogen detection in complex biological media. AFM allows direct (i.e., label-free) visualization and quantification of nanometer-sized viruses captured on a smooth, selective surface. AFM readout led to optimization of a capture substrate for feline calicivirus (FCV), and yielded a limit of detection of 3 x 10(6) FCV/mL. SERS-based detection of FCV, carried out in a sandwich-type assay, requires labelling of the substrate-bound FCV with a selective extrinsic Raman label (ERL). These studies yielded a limit of detection of 1 x 10(6) FCV/mL. The prospects of these two readout methods as additions to the arsenal of tools in bioterrorism prevention are briefly discussed.
Asunto(s)
Calicivirus Felino/aislamiento & purificación , Calicivirus Felino/ultraestructura , Microscopía de Fuerza Atómica/métodos , Espectrometría Raman/métodos , Inmunoensayo/métodos , Inmunoensayo/veterinariaRESUMEN
Subclinical illness associated with infection is thought to reduce performance and increase production costs in feedlot cattle, but underlying components remain largely unidentified. Vaccination is frequently used in feedlot settings but producers lack metrics that evaluate the effectiveness of vaccination programs. The goal of this study was to determine if levels of serum neutralizing antibody titers were predictive of levels of vaccine protection in a commercial setting. During this four-year study, Angus-Nellore steers housed in a production feedlot setting were assigned to 1 of 3 vaccine treatments: killed vaccine (kV), modified live virus (MLV) vaccine, or no vaccine (control), and were challenged with a noncytopathic 1b field strain of bovine viral diarrhea virus. Rectal temperature and levels of circulating lymphocytes and platelets were monitored following challenge. While no animals were diagnosed as clinically ill with respiratory disease, indicators of disease (pyrexia, lymphopenia, and thrombocytopenia) were observed. The MLV treatment elicited higher antibody titers to the vaccination than the kV, and calves in the MLV treatment had higher mean titers at challenge. The year that elicited the highest antibody response to the vaccination and the year with the lowest frequency of phenotypic responses to the challenge were not concurrent. The MLV treatment had the highest proportion, 34.68%, of animals that were protected against the challenge regardless of the pre-challenge antibody titer and had the fewest number of lymphopenia cases in response to the challenge. Both vaccine treatments mitigated thrombocytopenia when compared to the control treatment, and the MLV treatment reduced lymphopenia; however, these symptoms were not completely eliminated in vaccinated animals. Pyrexia was present in 40.11% of the animals, but no difference in the frequency of cases between treatments was observed. Pre-challenge vaccination response was not indicative of the level of protection nor was anamnestic antibody response correlated with health status.
Asunto(s)
Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Diarrea Mucosa Bovina Viral/inmunología , Diarrea Mucosa Bovina Viral/prevención & control , Virus de la Diarrea Viral Bovina Tipo 1/inmunología , Virus de la Diarrea Viral Bovina Tipo 2/inmunología , Vacunas Virales/inmunología , Animales , Bovinos , Memoria Inmunológica , Trombocitopenia/prevención & control , Trombocitopenia/virología , Vacunación/veterinaria , Vacunas Atenuadas/administración & dosificación , Vacunas Atenuadas/inmunología , Vacunas de Productos Inactivados/administración & dosificación , Vacunas de Productos Inactivados/inmunología , Vacunas Virales/administración & dosificaciónRESUMEN
Like other members from the Pestivirus genus, 'HoBi'-like pestiviruses cause economic losses for cattle producers due to both acute and persistent infections. The present study analyzed for the first time PI animals derived from a controlled infection with two different 'HoBi'-like strains where the animals were maintained under conditions where superinfection by other pestiviruses could be excluded. The sequence of the region coding for viral glycoproteins E1/E2 of variants within the swarms of viruses present in the PI calves and two viral inoculums used to generate them were compared. Differences in genetic composition of the viral swarms were observed suggesting that host factors can play a role in genetic variations among PIs. Moreover, PIs generated with the same inoculum showed amino acid substitutions in similar sites of the polyprotein, even in serum from PIs with different quasispecies composition, reinforcing that some specific sites in E2 are important for host adaptation.
Asunto(s)
Infecciones por Pestivirus/virología , Pestivirus/genética , Filogenia , Proteínas del Envoltorio Viral/genética , Adaptación Fisiológica , Animales , Bovinos , Clonación Molecular , Células Epiteliales/patología , Células Epiteliales/virología , Expresión Génica , Pestivirus/clasificación , Pestivirus/aislamiento & purificación , Cultivo Primario de Células , Proteínas Recombinantes/genética , Análisis de Secuencia de ADN , Cornetes Nasales/patología , Cornetes Nasales/virologíaRESUMEN
The genus Pestivirus of the family Flaviviridae consists of four recognized species: Bovine viral diarrhoea virus 1 (BVDV-1), Bovine viral diarrhoea virus 2 (BVDV-2), Classical swine fever virus (CSFV) and Border disease virus (BDV). Recently, atypical pestiviruses ('HoBi'-like pestiviruses) were identified in batches of contaminated foetal calf serum and in naturally infected cattle with and without clinical symptoms. Here, we describe the first report of a mucosal disease-like clinical presentation (MD) associated with a 'HoBi'-like pestivirus occurring in a cattle herd. The outbreak was investigated using immunohistochemistry, antibody detection, viral isolation and RT-PCR. The sequence and phylogenetic analysis of 5'NCR, N(pro) and E2 regions of the RT-PCR positive samples showed that four different 'HoBi'-like strains were circulating in the herd. The main clinical signs and lesions were observed in the respiratory and digestive systems, but skin lesions and corneal opacity were also observed. MD characteristic lesions and a pestivirus with cytopathic biotype were detected in one calf. The present study is the first report of a MD like presentation associated with natural infection with 'HoBi'-like pestivirus. This report describes the clinical signs and provides a pathologic framework of an outbreak associated with at least two different 'HoBi'-like strains. Based on these observations, it appears that these atypical pestiviruses are most likely underdiagnosed in Brazilian cattle.