scholarly journals Virulent Properties of Russian Bovine Viral Diarrhea Virus Strains in Experimentally Infected Calves

Scientifica ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Alexander G. Glotov ◽  
Tatyana I. Glotova ◽  
Svetlana V. Koteneva ◽  
Olga V. Semenova ◽  
Alexander A. Sergeev ◽  
...  

The results of experimental study of three noncytopathic and two cytopathic bovine viral diarrhea virus (BVDV) strains isolated from cattle in the Siberian region and belonging to the type 1 (subtypes 1a, 1b, and 1d) have been presented. All investigated strains caused the development of infectious process in the seronegative 4–6-month-old calves after aerosol challenge with the dose of 6 log10TCID50. The greatest virulence had noncytopathic strain and cytopathic strain related to the subtypes 1d and 1b, respectively. All strains in infected calves caused some signs of moderate acute respiratory disease and diarrhea: depression 3–5 days postinfection (p.i.), refusal to food, severe hyperthermia to 41.9°С, serous exudate discharges from the nasal cavity and eyes, transient diarrhea with blood, leukopenia (up to 2700 cells/mm3), and macroscopic changes in the respiratory organs and intestine. The infected animals recovered from 12 to 15 days p.i. and in 90% cases formed humoral immune response 25 days p.i. (antibody titers to BVDV: 1 : 4–1 : 16). Our results confirmed the presence of virulent BVDV1 strains and showed the need for researches on the molecular epidemiology of the disease, development of more effective diagnostic systems, and optimization of control programs with use of vaccines.

2007 ◽  
Vol 88 (3) ◽  
pp. 748-757 ◽  
Author(s):  
Cristina T. Rosas ◽  
Patricia König ◽  
Martin Beer ◽  
Edward J. Dubovi ◽  
B. Karsten Tischer ◽  
...  

Bovine viral diarrhea virus (BVDV) is an economically important pathogen of cattle that is maintained in the population by persistently infected animals. Virus infection may result in reproductive failure, respiratory disease and diarrhoea in naïve, susceptible bovines. Here, the construction and characterization of a novel vectored vaccine, which is based on the incorporation of genes encoding BVDV structural proteins (C, Erns, E1, E2) into a bacterial artificial chromosome of the equine herpesvirus type 1 (EHV-1) vaccine strain RacH, are reported. The reconstituted vectored virus, rH_BVDV, expressed BVDV structural proteins efficiently and was indistinguishable from parental vector virus with respect to growth properties in cultured cells. Intramuscular immunization of seronegative cattle with rH_BVDV resulted in induction of BVDV-specific serum neutralizing and ELISA antibodies. Upon experimental challenge infection of immunized calves with the heterologous BVDV strain Ib SE5508, a strong anamnestic boost of the neutralizing-antibody response was observed in all vaccinated animals. Immunized animals presented with reduced viraemia levels and decreased nasal virus shedding, and maintained higher leukocyte counts than mock-vaccinated controls.


2017 ◽  
Vol 15 (2) ◽  
pp. e05R01 ◽  
Author(s):  
Francisco J. Diéguez ◽  
Manuel Cerviño ◽  
Eduardo Yus

Bovine viral diarrhea virus (BVDV), a member of the genus Pestivirus of the family Flaviviridae, causes significant losses in cattle farming worldwide because of reduced milk production, increased mortality of young animals and reproductive, respiratory and intestinal problems. The virus is characterized by an important genetic, and consequently antigenic and pathogenic diversity. Knowing the variability of viral strains present in a population provides valuable information, particularly relevant for control programs development, vaccination recommendations and even identification of likely infection sources. Such information is therefore important at both local and regional levels. This review focuses on the genetic diversity of BVDV isolates infecting cattle in Spain over the last years. According to the published data, the most prevalent BVDV group in Spain was 1b, and to a lesser extent 1d, 1e and 1f. Besides, BVDV-2 has also been found in Spain with several ratified isolates. The studies carried out in Spain also showed increased genetic heterogeneity of BVDV strains, possibly due to a more intensive use of analytical tools available, presenting studies with increasingly greater sample sizes.


2020 ◽  
Vol 157 ◽  
pp. 569-576
Author(s):  
Laura Junqueira de Camargo ◽  
Tony Picoli ◽  
Geferson Fischer ◽  
Ana Claudia Oliveira de Freitas ◽  
Rodrigo Bozembecker de Almeida ◽  
...  

2016 ◽  
Vol 229 ◽  
pp. 1-7 ◽  
Author(s):  
Viviana Mari ◽  
Michele Losurdo ◽  
Maria Stella Lucente ◽  
Eleonora Lorusso ◽  
Gabriella Elia ◽  
...  

2008 ◽  
Vol 20 (1) ◽  
pp. 156 ◽  
Author(s):  
A. Bielanski ◽  
J. Algire ◽  
A. Lalonde

Bovine viral diarrhea virus (BVDV) infection affects cattle throughout the world. It causes significant economic losses in the cattle industry. The potential for transmission of a cytopathic biotype of BVDV by in vivo-derived embryos has been thought to be negligible. However, there is no study to prove non-transmission of the most common field isolate of noncytopathic biotype (NCPB) of BVDV by IVF embryos. Here we report on the preliminary outcome of embryo transfer (ET) of IVF embryos exposed in vitro to type-1 (NY-1) and type-2 (P-131) genotypes of NCPB of BVDV. For this experiment, IVF embryos were generated using standard methods which briefly involve: maturation of cumulus–oocyte complexes in TCM medium, fertilization of oocytes with BVDV-free semen, and culture of zygotes to the blastocyst stage in SOF medium without somatic cells. Day 7 blastocysts were exposed for 1 h to NY-1 or P-131 (103–107 TCID50 mL–1) BVDV strains before being washed (without trypsin) as recommended by IETS. Two embryos were transferred on each occasion. Embryo recipients were virus-free and anti-BVDV antibody-free prior to ET. The recipients remained individually in isolation premises after ET. In total, 126 ET procedures were performed resulting in 57 pregnancies and 34 calves born free of the infectious virus and BVDV antibodies (5 pregnancies are still pending). In total, 23 pregnancies were lost after 30 days. Exposure of embryos to type-2 BVDV resulted in a loss of 46% (17/37) of pregnancies after 30 days post-ET and 20 recipients seroconverted to BVDV. Within seroconverted and pregnant animals (n = 14), only 2 recipients maintained pregnancy and delivered uninfected calves at term. In contrast, exposure of embryos to type-1 caused 30% (6/20) of the pregnancy losses after 30 days and did not cause any seroconversion in ET recipients. After washing, 33% (3/9) and 38% (17/44) single embryos from the infected pool of IVF embryos tested positive for the BVDV. In conclusion, under these experimental conditions, a proportion of recipients was apparently infected after receipt of BVDV-exposed embryos. However, all of the calves that survived to term were BVDV-free and anti-BVDV antibody free.


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