scholarly journals Bluetongue in the Sultanate of Oman, a preliminary epidemiological study

1991 ◽  
Vol 107 (1) ◽  
pp. 87-97 ◽  
Author(s):  
W. P. Taylor ◽  
S. M. Al Busaidy ◽  
P. S. Mellor
Keyword(s):  
Epidemiological Study ◽  
Bluetongue Virus ◽  
Hot Spot ◽  
Neutralizing Antibody ◽  
Sultanate Of Oman ◽  
Agar Gel ◽  
Widespread Distribution ◽  
Previous Evidence ◽  
Immunodiffusion Test ◽  
Virus Activity

SUMMARYA group specific agar-gel immunodiffusion test was used to demonstrate that there is a frequent and widespread distribution of bluetongue virus throughout the Sultanate of Oman. The Culicoides midges C. imicola and C. schultzei, both capable of transmitting bluetongue group viruses, were recorded throughout the year. Although these studies did not establish that bluetongue is enzootic in Oman, type-specific neutralizing antibody results supported previous evidence for the existence of a Saudi Arabian bluetongue ecosystem. Variations in antibody evidence of virus activity within a restricted locality suggested a hot-spot theory concerning the perpetuation of the virus.

scholarly journals Bluetongue virus in a Nigerian dairy cattle herd: 1. Serological studies and correlation of virus activity to vector population

1983 ◽  
Vol 90 (2) ◽  
pp. 177-193 ◽  
Author(s):  
K. A. J. Herniman ◽  
J. P. T. Boorman ◽  
W. P. Taylor
Keyword(s):  
Bluetongue Virus ◽  
Light Trap ◽  
Survival Rates ◽  
Virus Transmission ◽  
Neutralizing Antibody ◽  
Decay Rates ◽  
Vector Population ◽  
Virus Activity ◽  
Serological Studies ◽  
Trap Catches

SUMMARYNewborn calves were bled at monthly intervals and examined for serum antibodies to bluetongue virus (BTV). Maternal immunity persisted for 3 months and it was possible to calculate decay rates for virus neutralizing antibody. Calves were subclinically infected with BTV within a few months of becoming susceptible and neutralization tests were used to deduce the serotype responsible. A profile of virus activity was built up over a 12 month period. Frequent light trap catches were used to examine the population dynamics of suspected Culicoides vector species. Two species, imicola and schultzei were present throughout the wet and dry seasons and survival rates were sufficiently long to account for virus transmission at any time of the year.

scholarly journals The epidemiology of bluetongue in Malawi

1988 ◽  
Vol 100 (3) ◽  
pp. 493-499 ◽  
Author(s):  
J. M. Haresnape ◽  
W. P. Taylor ◽  
S. A. M. Lungu
Keyword(s):  
Central Region ◽  
Rainy Season ◽  
Bluetongue Virus ◽  
Neutralizing Antibody ◽  
Dry Season ◽  
Virus Activity

SummaryA 4 year survey was undertaken in 1982–6 to examine the seasonal nature of bluetongue virus activity in Malawi. Bluetongue infection at Bwemba in Lilongwe district and Likasi in Mchinji district, both in the Central Region of Malawi, was detected by examining sera taken from calves at each site, at monthly intervals. The proportion of seronegative calves undergoing serocon version each month was used as a measure of virus activity. At both sides bluetongue virus activity was found to be most marked during the rainy season, with no activity detected during the dry season from July to September. Thus the pattern of bluetongue infection in Malawi is highly seasonal. Examination of type-specific neutralizing antibody showed that the prevalent serotypes varied from year to year.

scholarly journals Multivalent nanoparticle-based vaccines protect hamsters against SARS-CoV-2 after a single immunization

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Shiho Chiba ◽  
Steven J. Frey ◽  
Peter J. Halfmann ◽  
Makoto Kuroda ◽  
Tadashi Maemura ◽  
...  
Keyword(s):  
Coat Protein ◽  
Infectious Virus ◽  
Neutralizing Antibody ◽  
Vaccine Platform ◽  
Death Rates ◽  
Widespread Distribution ◽  
Syrian Hamsters ◽  
Vaccine Trials ◽  
Multiple Copies ◽  
Antibody Titers

AbstractThe COVID-19 pandemic continues to wreak havoc as worldwide SARS-CoV-2 infection, hospitalization, and death rates climb unabated. Effective vaccines remain the most promising approach to counter SARS-CoV-2. Yet, while promising results are emerging from COVID-19 vaccine trials, the need for multiple doses and the challenges associated with the widespread distribution and administration of vaccines remain concerns. Here, we engineered the coat protein of the MS2 bacteriophage and generated nanoparticles displaying multiple copies of the SARS-CoV-2 spike (S) protein. The use of these nanoparticles as vaccines generated high neutralizing antibody titers and protected Syrian hamsters from a challenge with SARS-CoV-2 after a single immunization with no infectious virus detected in the lungs. This nanoparticle-based vaccine platform thus provides protection after a single immunization and may be broadly applicable for protecting against SARS-CoV-2 and future pathogens with pandemic potential.

scholarly journals Analysis and phylogenetic comparisons of full-length VP2 genes of the 24 bluetongue virus serotypes

2007 ◽  
Vol 88 (2) ◽  
pp. 621-630 ◽  
Author(s):  
S. Maan ◽  
N. S. Maan ◽  
A. R. Samuel ◽  
S. Rao ◽  
H. Attoui ◽  
...  
Keyword(s):  
Bluetongue Virus ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Full Length ◽  
Molecular Diagnostic ◽  
Mammalian Host ◽  
Reading Frame ◽  
Diagnostic Assays ◽  
Primary Determinant ◽  
Serotype Identification

The outer capsid protein VP2 of Bluetongue virus (BTV) is a target for the protective immune response generated by the mammalian host. VP2 contains the majority of epitopes that are recognized by neutralizing antibodies and is therefore also the primary determinant of BTV serotype. Full-length cDNA copies of genome segment 2 (Seg-2, which encodes VP2) from the reference strains of each of the 24 BTV serotypes were synthesized, cloned and sequenced. This represents the first complete set of full-length BTV VP2 genes (from the 24 serotypes) that has been analysed. Each Seg-2 has a single open reading frame, with short inverted repeats adjacent to conserved terminal hexanucleotide sequences. These data demonstrated overall inter-serotype variations in Seg-2 of 29 % (BTV-8 and BTV-18) to 59 % (BTV-16 and BTV-22), while the deduced amino acid sequence of VP2 varied from 22.4 % (BTV-4 and BTV-20) to 73 % (BTV-6 and BTV-22). Ten distinct Seg-2 lineages (nucleotypes) were detected, with greatest sequence similarities between those serotypes that had previously been reported as serologically ‘related’. Fewer similarities were observed between different serotypes in regions of VP2 that have been reported as antigenically important, suggesting that they may play a role in the neutralizing antibody response. The data presented form an initial basis for BTV serotype identification by sequence analyses and comparison of Seg-2, and for development of molecular diagnostic assays for individual BTV serotypes (by RT-PCR).

Immunodiffusion Technique for the Identification of Animal Species

1971 ◽  
Vol 54 (5) ◽  
pp. 1152-1156 ◽  
Author(s):  
H Guy Fugate ◽  
Shelton R Penn
Keyword(s):  
Species Identification ◽  
Animal Species ◽  
Ring Test ◽  
Species Determination ◽  
Agar Gel ◽  
Simple Method ◽  
Tissue Samples ◽  
Immunodiffusion Test ◽  
Meat Animal ◽  
Antigen Antibody

Abstract An agar-gel immunodiffusion technique was developed for the identification of meat animal species. A pattern of wells and troughs was cut from agar plates. The wells and troughs contained antigens and antisera, respectively. The diffusion of the antigens and antisera through the agar results in the formation of precipitin lines when optimum antigen-antibody conditions exist. The interpretation of the reactions depends upon the position of the formed precipitin lines in relation to each other. Eleven of 12 mixed tissue samples submitted to the authors’ laboratory for species determination were identified correctly by the agar-gel immunodiffusion test. The test is a relatively rapid and simple method of confirming the results of the tube precipitin ring test for animal species identification.

scholarly journals Quantal and graded dose-responses of bluetongue virus: a comparison of their sensitivity as assay methods for neutralizing antibody

1966 ◽  
Vol 64 (2) ◽  
pp. 231-244 ◽  
Author(s):  
Sven-Eric Svehag
Keyword(s):  
Poisson Distribution ◽  
Bluetongue Virus ◽  
Neutralizing Antibody ◽  
Survival Times ◽  
Response Curves ◽  
Virus Particles ◽  
The Best Approximation ◽  
Graded Responses ◽  
Quantal Responses ◽  
Random Variation

The sensitivity of quantal and graded responses to mouse-adapted bluetongue virus for the detection of neutralizing antibody was compared using probit and rankit analysis. The graded response, based on survival times, allowed the demonstration of antibody in highly dilute serum, in which antibody was not detected by the quantal response recording percentage death.Quantal responses to bluetongue virus variants were compared with theoretical dose-response curves constructed according to the Poisson distribution for the random variation of virus particles in inocula. Of these theoretical curves the first term in the Poisson distribution gave the best approximation to the experimental data but the fit to normal distribution curves was better. The quantal responses to bluetongue virus did not appear to reflect the random variation of one-or-more infectious virus particles in inocula.In graded responses to bluetongue virus, a rectilinear relationship was observed between reciprocal harmonic means of survival times and log virus dilutions.

scholarly journals CD8 T Cell Responses to an Immunodominant Epitope within the Nonstructural Protein NS1 Provide Wide Immunoprotection against Bluetongue Virus in IFNAR−/−Mice

2018 ◽  
Vol 92 (16) ◽  
Author(s):  
Alejandro Marín-López ◽  
Eva Calvo-Pinilla ◽  
Diego Barriales ◽  
Gema Lorenzo ◽  
Alejandro Brun ◽  
...  
Keyword(s):  
T Cell ◽  
Bluetongue Virus ◽  
Neutralizing Antibodies ◽  
Nonstructural Protein ◽  
T Cell Responses ◽  
Neutralizing Antibody ◽  
Cd8 T Cell ◽  
T Cell Response ◽  
Cell Responses ◽  
N Terminus

ABSTRACTThe development of vaccines against bluetongue, a prevalent livestock disease, has been focused on surface antigens that induce strong neutralizing antibody responses. Because of their antigenic variability, these vaccines are usually serotype restricted. We now show that a single highly conserved nonstructural protein, NS1, expressed in a modified vaccinia Ankara virus (MVA) vector can provide multiserotype protection in IFNAR−/−129 mice against bluetongue virus (BTV) that is largely dependent on CD8 T cell responses. We found that the protective antigenic capacity of NS1 resides within the N terminus of the protein and is provided in the absence of neutralizing antibodies. The protective CD8 T cell response requires the presence of a specific peptide within the N terminus of NS1, since its deletion ablates the efficacy of the vaccine formulation. These data reveal the importance of the nonstructural protein NS1 in CD8 T cell-mediated protection against multiple BTV serotypes when vectorized as a recombinant MVA vaccine.IMPORTANCEConventional vaccines have controlled or limited BTV expansion in the past, but they cannot address the need for cross-protection among serotypes and do not allow distinguishing between infected and vaccinated animals (DIVA strategy). There is a need to develop universal vaccines that induce effective protection against multiple BTV serotypes. In this work we have shown the importance of the nonstructural protein NS1, conserved among all the BTV serotypes, in CD8 T cell-mediated protection against multiple BTV serotypes when vectorized as a recombinant MVA vaccine.

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