RESUMEN
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.
Asunto(s)
Diarrea Mucosa Bovina Viral , Virus de la Diarrea Viral Bovina Tipo 1 , Virus de la Diarrea Viral Bovina , Brotes de Enfermedades , Filogenia , Animales , Bovinos , Diarrea Mucosa Bovina Viral/virología , Diarrea Mucosa Bovina Viral/epidemiología , Diarrea Mucosa Bovina Viral/prevención & control , Brotes de Enfermedades/veterinaria , Femenino , Virus de la Diarrea Viral Bovina Tipo 1/genética , 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/inmunología , Brasil/epidemiología , Virus de la Diarrea Viral Bovina/genética , Virus de la Diarrea Viral Bovina/clasificación , Virus de la Diarrea Viral Bovina/aislamiento & purificación , Virus de la Diarrea Viral Bovina/inmunología , Genotipo , Vacunas Virales/inmunología , Ensayo de Inmunoadsorción Enzimática , Industria Lechera , Vacunación/veterinaria , Anticuerpos Antivirales/sangreRESUMEN
Bovine viral diarrhea virus-1 (BVDV-1, Pestivirus A) and BVDV-2 (Pestivirus B) have been clustered into 21 and 4 subtypes, respectively. This genetic diversity, in addition to the lack of consensus on which genomic region to use for BVDV subtyping, has resulted in conflicting classifications depending on the target analyzed. Here, we investigated which genes or UTRs would reproduce the phylogeny obtained by complete genome (CG) analyses. The study was carried out with 91 (BVDV-1) and 85 (BVDV-2) CG available on GenBank database. The viruses were subtyped by analyzing their CG, as well as their individual genes and UTRs (complete 3' and 5'UTRs, and partial 5'UTR); and the phylogeny results were compared to each other. The sequences were aligned using the ClustalW multiple method (BioEdit Alignment Editor software, v.7.0.5.3) and the phylogenetic analyses were performed by the Maximum Likelihood method (MEGA-X software, v.10.2.4), with 1000 bootstrap replicates. The best analysis model for each gene/UTR was defined using the jModelTest software. The geodesic distance between the CG (reference) and individual genes/UTRs trees was also calculated (TreeCmp software, v.2.0). In general, 3'UTR-based analyses, followed by 5'UTR, presented the least reliable subtyping results. Regarding BVDV-1, phylogeny based on C, Erns, E1, E2, p7, NS2, NS3, NS4B, NS5A and NS5B was consistent with that of CG. In contrast, analyses performed with individual BVDV-2 genes showed at least one different clustering from the phylogeny based on the CG. After analyzing the geodesic distance between the CG and genes/UTRs trees, we observed that NS4B (for BVDV-1) and NS5A (BVDV-2) presented the closest topology and edge length to the CG analyses. Finally, comparing the phylogeny performed with the CG and the genes/UTRs, as well as the geodesic distance between them, we understand that NS4B and NS5A represent the most suitable targets for BVDV-1 and -2 subtyping, respectively, and may be considered in future phylogenetic studies.
Asunto(s)
Virus de la Diarrea Viral Bovina Tipo 1/genética , Virus de la Diarrea Viral Bovina Tipo 2/genética , Genes Virales , Filogenia , Virus de la Diarrea Viral Bovina Tipo 1/clasificación , Virus de la Diarrea Viral Bovina Tipo 2/clasificación , Secuenciación Completa del GenomaRESUMEN
Bovine viral diarrhea virus (BVDV) is a major pathogen in cattle herds. Considering the epidemiological importance of pestiviruses and the process of wild boar invasion in Brazil, this study aimed to investigate the presence of BVDV in free-living boars. Forty-nine free-living wild boars were collected by exotic wildlife controller agents in 2017 and 2018. The presence of BVDV antibodies was evaluated in 42 serum samples using the virus neutralization test, and the detection of BVDV RNA was performed from the 5'UTR genomic region by RT-PCR assay in 49 lung tissue samples followed by sequencing of amplicons. BVDV neutralizing antibodies in serum were not identified in any of the evaluated samples. However, 3/49 (6.12%) lung samples were positive for BVDV RNA and classified one as BVDV-1a and two as 1d subgenotype. This report identified BVDV RNA in free-living wild boars and these results should be considered in BVDV control programs, especially in extensive beef cattle rearing systems.
Asunto(s)
Animales Salvajes/virología , Virus de la Diarrea Viral Bovina Tipo 1/aislamiento & purificación , Sus scrofa/virología , Regiones no Traducidas 5'/genética , Animales , Anticuerpos Antivirales/sangre , Brasil , 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/inmunología , Genotipo , Pulmón/virología , Infecciones por Pestivirus/veterinaria , Infecciones por Pestivirus/virología , Filogenia , ARN Viral/genética , Porcinos , Enfermedades de los Porcinos/virologíaRESUMEN
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
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 1 (BVDV-1) belongs to the genus Pestivirus within the family Flaviviridae. Based on the 5' untranslated region (UTR) sequence, BVDV-1 can be divided into at least 17 subtypes (1a though 1q). BVDV-1i is an uncommon subtype that has been reported in the United Kingdom and Uruguay. Here, we report the complete genome sequence of the first subtype 1i BVDV-1 (strain ACM/BR/2016) isolated from cattle in southern Brazil. The genome is 12,231 nt in length and contains a single ORF that encodes a polyprotein of 3,896 amino acids, flanked by 5' and 3'UTRs of 325 and 220 nt, respectively. Phylogenetic inferences based on the whole genome, the 5'UTR, and the Npro region showed that strain ACM/BR/2016 is closely related to previously characterized BVDV-1i members. Its 5'UTR shares the highest nucleotide identity (90.5%) with BVDV-1i strains from United Kingdom, and its Npro is most closely related to that of a Uruguayan strain (90.6%). To the best of our knowledge, this is the first BVDV-1i strain from which the whole genome has been completely sequenced and characterized. The complete genome of a BVDV-1i will help future studies on pestivirus evolution and heterogeneity.
Asunto(s)
Diarrea Mucosa Bovina Viral/virología , Virus de la Diarrea Viral Bovina Tipo 1/aislamiento & purificación , Genoma Viral , Regiones no Traducidas 5' , Animales , Brasil , Bovinos , Virus de la Diarrea Viral Bovina Tipo 1/clasificación , Virus de la Diarrea Viral Bovina Tipo 1/genética , Genómica , Genotipo , Filogenia , ARN Viral/genéticaRESUMEN
Bovine viral diarrhea virus (BVDV) belongs to the Pestivirus genus, which is further divided into subgenotypes (1a-1u and 2a-c). When persistent infection occurs, the calf will be immunotolerant to BVDV and possibly develop mucosal disease. This study describes an outbreak of BVDV-1d-induced mucosal disease lacking intestinal lesions. Eleven calves presented with anorexia, sialorrhea, lameness, recumbency, and death. Three calves were necropsied, showing ulceration of the interdigital skin and the oral and nasal mucosa; linear ulcers in the tongue, esophagus, and rumen; and rounded ulcers in the abomasum. Microscopically, mucosa and skin had superficial necrosis, with single-cell necrosis and vacuolation in epithelial cells, and severe parakeratosis. Immunohistochemistry (IHC) showed BVDV antigen in the cytoplasm of epithelial cells in skin and mucosa. All 11 dead calves were positive upon reverse transcription-polymerase chain reaction (RT-PCR) for the detection of Pestivirus along with another 11 live calves from the herd, which were positive again by RT-PCR and IHC after a 4-week interval. Sequencing of the 5' untranslated region and N-terminal protease showed that viruses from these 22 calves were homologous and of subgenotype BVDV-1d. Cytopathic BVDV was isolated from 8 of 11 dead calves, but only noncytopathic BVDV was isolated from the 11 live animals. The findings indicate that this was an outbreak of mucosal disease caused by BVDV-1d, with high morbidity, and lesions restricted to the upper alimentary system and skin and absent from intestine. Thus, the epidemiological and pathological features in this form of mucosal disease may be similar to vesicular diseases, including foot and mouth disease.
Asunto(s)
Diarrea Mucosa Bovina Viral/virología , Virus de la Diarrea Viral Bovina Tipo 1/clasificación , Brotes de Enfermedades/veterinaria , Intestinos/patología , Animales , Diarrea Mucosa Bovina Viral/patología , BovinosRESUMEN
Infection of water buffaloes (Bubalus bubalis) with bovine viral diarrhea viruses (BVDV) has been confirmed in several studies by serological and molecular techniques. In order to determine the presence of persistently infected animals and circulating species and subtypes of BVDV we conducted this study on a buffalo herd, whose habitat was shared with bovine cattle (Bossp.). Our serological results showed a high level of positivity for BVDV-1 and BVDV-2 within the buffalo herd. The molecular analyses of blood samples in serologically negative animals revealed the presence of viral nucleic acid, confirming the existence of persistent infection in the buffaloes. Cloning and sequencing of the 5' UTR of some of these samples revealed the presence of naturally mix-infected buffaloes with at least two different subtypes (1a and 1b), and also with both BVDV species (BVDV-1 and BVDV-2).
Asunto(s)
Búfalos/virología , Portador Sano/veterinaria , Coinfección/virología , Virus de la Diarrea Viral Bovina Tipo 1/aislamiento & purificación , Virus de la Diarrea Viral Bovina Tipo 2/aislamiento & purificación , Infecciones por Pestivirus/veterinaria , Viremia/veterinaria , Regiones no Traducidas 5'/genética , Animales , Anticuerpos Antivirales/sangre , Argentina/epidemiología , Enfermedades Asintomáticas , Diarrea Mucosa Bovina Viral/epidemiología , Diarrea Mucosa Bovina Viral/transmisión , Portador Sano/epidemiología , Portador Sano/virología , Bovinos/microbiología , ADN Viral/genética , 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/inmunología , 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/inmunología , Reservorios de Enfermedades , Reacciones Falso Negativas , Especificidad del Huésped , Infecciones por Pestivirus/epidemiología , Infecciones por Pestivirus/transmisión , Infecciones por Pestivirus/virología , Filogenia , ARN Viral/sangre , Especificidad de la Especie , Viremia/epidemiología , Viremia/virologíaRESUMEN
Llamas and alpacas are domesticated South American camelids (SACs) important to ancestral population in the Altiplano region, and to different communities worldwide where they have been introduced. These ungulates have shown to be susceptible to several livestock viral pathogens such as members of the Pestivirus genus, in particular Bovine Viral Diarrhea (BVDV), but there is little data available on Pestivirus infections in SACs. In this study we aimed to detect and identify Pestivirus genotypes and subgroups infecting SACs in both wild and confined environments. Samples were collected from 136 llamas and 30 alpacas from different areas in the Chilean Altiplano (wild animals), and from 22 llamas and 26 alpacas diagnosed as Pestivirus positive from the Metropolitana region in Chile (confined animals). Seroneutralization tests showed titers lower than 2 in all 166 samples from Chilean Altiplano. These samples were also negative to BVDV isolation, indicating that these animals have not been exposed to Pestivirus. After reactivation of positive samples from the Metropolitana region, the 5' non-codifying region (5'NCR) and E2 glycoprotein were amplified by RT-PCR from the Pestivirus genome. Viral sequences were pairwise compared and phylogenetic trees were constructed. The 5'NCR analysis showed that all 12 sequenced isolates belonged to BVDV-1. Of particular interest, isolates from eight llama and two alpaca were BVDV-1j and two alpacas were BVDV-1b. In agreement with these results, E2 phylogenetic analysis rendered a similar grouping indicating that all 16 isolates belong to BVDV-1. However, the lower availability of E2 sequences determines the creation of a smaller number of sub-groups than the 5'NCR sequences. Based on the E2 sequences, the 5'NCR BVDV 1j group consisting of all the llamas and 3 alpacas are completely included in the E2 BVDV 1e group. Due to the universal availability of the 5'NCR segment, we propose the classification of these Chilean llamas and alpacas Pestivirus isolates as BVDV 1j and BVDV 1b respectively. Thus, this is the first time BVDV-1j is obtained in SACs. In addition, these results indicate Pestivirus infection in llamas and alpacas is associated with bovine population as genotypes and sub-groups are the same as those affecting Chilean livestock.
Asunto(s)
Camélidos del Nuevo Mundo/virología , Virus de la Diarrea Viral Bovina Tipo 1/genética , Infecciones por Pestivirus/veterinaria , Infecciones por Pestivirus/virología , Animales , Chile , Virus de la Diarrea Viral Bovina Tipo 1/clasificación , Virus de la Diarrea Viral Bovina Tipo 1/aislamiento & purificación , Genotipo , Infecciones por Pestivirus/genética , Filogenia , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
Bovine Viral Diarrhea Virus (BVDV) is widespread in cattle in Brazil and research shows its large antigenic variability. Available vaccines are produced with virus strains isolated in other countries and may not be effective. In this study, inactivated vaccines containing the Brazilian BVDV-Ib IBSP11 isolate were developed and tested on 6 groups of 10 guinea pigs (Cavia porcellus). Animals in groups A and C received an aqueous vaccine (aluminum hydroxide); B and D groups received an oily vaccine (Montanide ISA50); Group E positive-control animals were given an imported commercial vaccine with BVDV-Ia Singer; Group F animals were sham vaccinated (negative control). Groups A, B and E received two doses, and Groups C and D, three, every 21 days. Twelve blood samples were taken, at 21-day intervals over 231 days, and evaluated for antibody titer through virus-neutralization (VN), using a homologous strain (IBSP11), and a heterologous strain (BVDV-Ia NADL). Most animals, 42 days following the first dose, seroconverted to both strains and, after the second dose, there was a significant increase of titers in all groups. The oily formulation induced greater response after the third administration. This increase was not observed with the aqueous vaccines, regardless of the virus used in the VN. Antibody decline was more rapid in animals that received aqueous vaccines. The results showed the importance of studying the influence of endemic strains of commercial vaccines, to improve the efficacy of BVD vaccination. Use of the endemic strain in vaccine formulation presented promising results, as well as the use of guinea pigs as a laboratory model.
Asunto(s)
Anticuerpos Antivirales/sangre , Diarrea Mucosa Bovina Viral/inmunología , Virus de la Diarrea Viral Bovina Tipo 1/genética , Virus de la Diarrea Viral Bovina Tipo 1/inmunología , Vacunas Virales/inmunología , Animales , Anticuerpos Antivirales/inmunología , Diarrea Mucosa Bovina Viral/virología , Brasil , Bovinos , Química Farmacéutica , Virus de la Diarrea Viral Bovina Tipo 1/clasificación , Relación Dosis-Respuesta Inmunológica , Femenino , Genotipo , Cobayas , Inmunidad Humoral , Inyecciones Subcutáneas/veterinaria , Modelos Animales , Pruebas de Neutralización/veterinaria , Distribución Aleatoria , Vacunas de Productos Inactivados/administración & dosificación , Vacunas de Productos Inactivados/inmunología , Vacunas Virales/administración & dosificaciónRESUMEN
When first described in 1946, bovine viral diarrhea (BVD) was characterized as an acute transmissible disease associated with severe leucopenia, high fever, depression, diarrhea, gastrointestinal erosions, and hemorrhages. Recently the severe acute form has been related only to some hypervirulent BVDV-2 strains. This article reports the detection of BVDV-1b associated with an acute and fatal outbreak of BVD in a Brazilian beef cattle herd. Depression, anorexia, watery diarrhea, sialorrhea, and weakness were observed in six steers. One of these animals was evaluated for laboratorial, clinical, and pathological alterations. Laboratory findings were non-specific; clinically, the animal was weak, with dehydration and erosive oral lesions. Pathological alterations were predominant at the tongue, esophagus, and rumen. A RT-PCR assay using primers to partially amplify the 5' untranslated region (5'UTR) of the BVDV genome was performed and identified BVDV in all clinical samples analyzed. Phylogenetic analysis of BVDV derived from lymph node revealed that this strain was clustered within the BVDV subtype 1b. This differentiating was only possible to be performed by molecular characterization since both clinical presentation and pathologic findings were similar to BVDV-2 infection.
Asunto(s)
Diarrea Mucosa Bovina Viral/epidemiología , Enfermedades de los Bovinos/virología , Virus de la Diarrea Viral Bovina Tipo 1/clasificación , Virus de la Diarrea Viral Bovina Tipo 1/genética , Brotes de Enfermedades/veterinaria , Animales , Brasil/epidemiología , Bovinos , Masculino , Orquiectomía , Filogenia , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
Thirty-three pestiviruses isolated from bovines on different farms in Chile were characterized at the molecular level. The 5'-untranslated region (5'UTR) of the isolates was amplified by reverse transcription-polymerase chain reaction (RT-PCR) and subsequently digested with restriction enzymes (RE) Bgl I, Xho I and Pst I. Furthermore, the isolates were amplified by differential RT-PCR, which selectively amplified bovine viral diarrhea virus type 2 (BVDV-2) but not bovine viral diarrhea virus type 1 (BVDV-1). Of the 33 isolates, 16 were classified as BVDV-1 and 17 as BVDV-2. Phylogenetic analysis of the PCR-amplified fragments from 14 isolates showed the presence of viruses belonging to the BVDV-1a, BVDV-1b, BVDV-1c, and BVDV-2 types. Antigenicity of some viruses belonging to both genotypes was studied by cross-seroneutralization, revealing great antigenic differences among them. It is concluded that BVDV viruses circulating in Chile are genetically and antigenically heterogeneous, comprising isolates of genogroups 1 and 2.