scholarly journals Assessing the antigenicity of different VP3 regions of infectious bursal disease virus in chickens from South Brazil

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Ana Paula Gori Palka ◽  
Tatiana Reichert Assunção de Matos ◽  
Claudemir de Souza ◽  
Danilo Santos Eugênio ◽  
Marco Aurélio Krieger ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Infectious Bursal Disease ◽  
Enzyme Linked Immunosorbent Assay ◽  
Post Vaccination ◽  
Immunological Status ◽  
Bursal Disease ◽  
Linear Epitopes ◽  
Immunogenic Proteins ◽  
Diagnostic Reagent ◽  
South Brazil

Abstract Background Infectious bursal disease (IBD), also known as Gumboro disease, is a viral infection that causes mortality and immunosuppression in chickens (Gallus gallus). VP2 and VP3 are the major structural viral capsid components and are the most immunogenic proteins of IBD virus (IBDV). Reliable diagnostic tests using VP2 and VP3 produced in heterologous systems are important tools to control this infection. One advantage of an IBD diagnostic based on VP3, over those that use VP2, is that VP3 has linear epitopes, enabling its production in bacteria. Results We tested the suitability of recombinant VP3 (rVP3) as a diagnostic reagent in an enzyme-linked immunosorbent assay (ELISA). Compared with a commercial test, rVP3 ELISA showed high sensitivity and specificity as a diagnostic tool for vaccinated animals. In addition, rVP3, but not the commercial ELISA, was able to detect antibodies in nonvaccinated chickens, probably developed against circulating IBDV strains. It was possible the assessment of VP3 regions antigenicity using chicken antisera. Conclusions The full-length recombinant VP3 can be used to assess post vaccination immunological status of chickens and its production is feasible and inexpensive. The evaluation of VP3 regions as candidates for general use in the diagnosis of IBD in chickens should be conducted with caution. Our work was the first to identify several regions of VP3 recognized by chicken antibodies.

scholarly journals STUDY THE EFFECT OF MYCOPLASMA CONTAMINATION OF EGGS USED IN VIRUS TITRATION AND EFFICACY OF SOME LIVE ATTENUATED POULTRY VIRAL VACCINES

2016 ◽  
Vol 10 (1) ◽  
pp. 216 ◽  
Author(s):  
Marwa Fathy ◽  
Mounir M. El-safty ◽  
Jakeen K. El-jakee ◽  
Howaida I. Abd-alla ◽  
Hala Mahmoud
Keyword(s):  
Disease Virus ◽  
Newcastle Disease ◽  
Disease Process ◽  
Mycoplasma Gallisepticum ◽  
Infectious Bursal Disease ◽  
Enzyme Linked Immunosorbent Assay ◽  
Infectious Bronchitis ◽  
Bursal Disease ◽  
Specific Pathogen ◽  
Viral Vaccines

ABSTRACTObjective: The study of Mycoplasma gallisepticum (MG) infection is needed, not only to understand the disease process but also to understand theinterference with the evaluation of some live viral poultry vaccines. This study aims to investigate the titration and potency of some live attenuatedpoultry viral vaccines; Newcastle disease, infectious bronchitis, infectious bursal disease, and Reo in both specific pathogen-free (SPF) embryonatedchicken eggs (ECEs) and chickens.Methods: Titration of live attenuated viral poultry vaccines in ECEs was carried out by dividing the inoculated eggs into four groups; the pre-,simultaneously-, post-, and non-MG contaminated. MG effect on the potency test was carried out using seventeen groups of SPF chickens (25 chicken/group) placed into separate isolators. Each live attenuated viral poultry vaccine was inoculated into 4 groups.Results: The highest titer of these vaccines that appeared in MG pre- contaminated ECEs were 1011, 107.5, 107.9, and 10, respectively. The lowest vaccinetiters that appeared in non-MG contaminated ECEs were 108, 106, 106.8, and 1067.5, respectively. Although the potency of these previous vaccines indicated thatthe highest antibodies titer that appeared in MG pre-infected vaccinated chickens were 7.5 log, 36 enzyme-linked immunosorbent assay unit (EU), and42 EU, respectively; the lowest antibodies titer that appeared in non-MG infected vaccinated chickens were 6.5 log22, 12 EU, 17 EU, and 10 EU, respectively.Conclusion: The present study findings underline the importance of using Mycoplasma -free eggs or chicken for the production of virus vaccines.Keywords: Mycoplasma gallisepticum, Newcastle disease virus, Infectious bronchitis virus, Infectious bursal disease virus, Reo virus, Chicken, Specificpathogen-free eggs.

PSX-B-24 Influence of the immunomodulatory drug Azoxivet on the post-vaccination immune response in laying hens

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 269-269
Author(s):  
Valentina Sabrekova ◽  
Maxim Korenyuga ◽  
Elena Konovalova ◽  
Natalia Rodionova
Keyword(s):  
Immune Response ◽  
Newcastle Disease ◽  
Laying Hens ◽  
Positive Influence ◽  
The Body ◽  
Infectious Bursal Disease ◽  
Post Vaccination ◽  
Before And After ◽  
Bursal Disease ◽  
Immunomodulatory Drug

Abstract Vaccination is a primary way to prevent infectious disease in poultry. The quality of immune response depends on the immune status of the body which, in turn, depends on many endogenous and exogenous factors. This study analyzed the effect of the immunomodulatory drug Azoxivet on the immune response in laying hens after vaccination against Newcastle Disease and Infectious Bursal Disease. There were 4 groups of Loman White cross laying hens (n=20). At age 120 days, all hens habitated in individual cages with an area of 0,15 m2. The conditions of keeping and feeding matched breed requirements. All groups were vaccinated against Newcastle Disease (NDV) (LaSota strain) and Infectious Bursal Disease (IBD) (Winterfield 2512 strain). All groups received Azoxivet (Az) at a dose of 0,3 mg/kg in water three times daily. Blood sera were collected weekly for serological studies using BioChek IBD and NDV test systems. The antibody level of all hens before and after vaccination: 1378 (IBD+Az) vs. 1674,93 (IBD) (P < 0,05), 5194,75 (NDV+Az) vs. 5612,87 (NDV) (P < 0,05). After one week of vaccination: 5931,25 (IBD+Az) vs. 5006,14 (IBD) (P < 0,05), 6207,58 (NDV+Az) vs. 5765,21 (NDV) (P < 0,05). Two weeks: 11086,00 (IBD+Az) vs. 10485,83 (IBD) (P < 0,05), 11255,25 (NDV+Az) vs. 8478,75 (NDV) (P < 0,05). Three weeks: 11478 (IBD+Az) vs. 8286 (IBD) (P < 0,05), 14725 (NDV+Az) vs. 12677 (NDV) (P < 0,05). Four weeks: 12999 (IBD+Az) vs. 1009,67 (IBD) (P < 0,05), 17399 (NDV+Az) vs. 16373,17 (NDV) (P < 0,05). Five weeks: 13601,15 (IBD+Az) vs. 9021,30 (IBD) (P < 0,05), 19671 (NDV+Az) vs. 16309 (NDV) (P < 0,05). Thus, Azaxul had a positive influence on the post-vaccination immune response in laying hens when used after Newcastle Disease and Infectious Bursal Disease vaccines. The results of the study can be used to improve disease prevention in poultry farming.

scholarly journals Development of a Novel Assay Based on Plant-Produced Infectious Bursal Disease Virus VP3 for the Differentiation of Infected From Vaccinated Animals

2021 ◽  
Vol 12 ◽  
Author(s):  
Alessio Bortolami ◽  
Marcello Donini ◽  
Carla Marusic ◽  
Chiara Lico ◽  
Charifa Drissi Touzani ◽  
...  
Keyword(s):  
Disease Virus ◽  
Infectious Bursal Disease Virus ◽  
Severe Infection ◽  
Bursa Of Fabricius ◽  
Infectious Bursal Disease ◽  
Enzyme Linked Immunosorbent Assay ◽  
Broiler Chicks ◽  
The Novel ◽  
Bursal Disease ◽  
Specific Pathogen

Infectious bursal disease virus is the causative agent of Gumboro disease, a severe infection that affects young chickens and is associated with lymphoid depletion in the bursa of Fabricius. Traditional containment strategies are based either on inactivated or live-attenuated vaccines. These approaches have several limitations such as residual virulence or low efficacy in the presence of maternally derived antibodies (MDA) but, most importantly, the impossibility to detect the occurrence of natural infections in vaccinated flocks. Therefore, the development of novel vaccination strategies allowing the differentiation of infected from vaccinated animals (DIVA) is a priority. Recently, commercial vectored and experimental subunit vaccines based on VP2 have been proved effective in protecting from clinical disease and posed the basis for the development of novel DIVA strategies. In this study, an engineered version of the VP3 protein of IBDV (His-VP3) was produced in plants, successfully purified from Nicotiana benthamiana leaves, and used to develop an enzyme-linked immunosorbent assay (ELISA) for the detection of anti-VP3 antibodies. The His-VP3 ELISA was validated with a panel of 180 reference sera and demonstrated to have 100% sensitivity (95% CI: 94.7–100.0) and 94.17% specificity (95% CI: 88.4–97.6). To evaluate the application of His-VP3 ELISA as a DIVA test, the novel assay was used to monitor, in combination with a commercial kit, detecting anti-VP2 antibodies, the immune response of chickens previously immunized with an inactivated IBDV vaccine, a recombinant Turkey herpes virus carrying the VP2 of IBDV (HVT-ND-IBD) or with plant-produced VP2 particles. The combined tests correctly identified the immune status of the vaccinated specific pathogen free white-leghorn chickens. Moreover, the His-VP3 ELISA correctly detected MDA against VP3 in commercial broiler chicks and showed that antibody titers fade with time, consistent with the natural decrease of maternally derived immunity. Finally, the novel assay, in combination with a VP2-specific ELISA, demonstrated its potential application as a DIVA test in chickens inoculated with VP2-based vaccines, being able to detect the seroconversion after challenge with a very virulent IBDV strain.

Recent trends in the molecular diagnosis of infectious bursal disease viruses

2004 ◽  
Vol 5 (2) ◽  
pp. 313-316 ◽  
Author(s):  
Daral J. Jackwood
Keyword(s):  
Infectious Bursal Disease ◽  
Enzyme Linked Immunosorbent Assay ◽  
Strain Identification ◽  
Dye Molecules ◽  
Rt Pcr ◽  
Isolation And Characterization ◽  
Antigen Capture ◽  
Bursal Disease ◽  
Serotype 1 ◽  
Pcr Assays

AbstractInfectious bursal disease virus (IBDV) causes an immunosuppressive disease in young chickens. Two serotypes of this double-stranded RNA virus exist but only serotype 1 viruses cause disease in chickens. Detection and strain identification of IBDV is important because antigenic subtypes found within serotype 1 make it necessary to tailor vaccination programs to the antigenic type found in the bird's environment. Because conventional virus isolation and characterization are not practical for routine diagnosis of IBDV, antigen-capture enzyme-linked immunosorbent assay (ELISA) and molecular assays based on reverse transcription–polymerase chain reaction (RT-PCR) technology were developed. Compared with antigen-capture ELISA, RT-PCR assays have greater versatility and are more sensitive and specific. Strain identification has been accomplished using a variety of post-RT-PCR assays, including restriction enzyme digestion of the RT-PCR products. The resulting restriction fragment length polymorphisms (RFLP) are used to differentiate viruses into molecular groups that correlate with antigenic and pathogenic types. Recently, two types of real-time RT-PCR have been used to identify and differentiate strains of IBDV. Both methods use distance-dependent interaction between two dye molecules, known as fluorescence resonance energy transfer (FRET). The dye molecules are attached to one or more nucleotide probes that detect specific nucleotide sequences of the virus. Our laboratory has used a two-probe assay to identify single-nucleotide mutations among IBDV strains. A mutation probe is used in this assay to detect substitution mutations in a region of the viral genome that encodes a neutralizing epitope of the virus. These assays are accurate, reliable and inexpensive compared with conventional RT-PCR because they do not require RFLP or other labor-intensive post-RT-PCR assays to distinguish viral strains.

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