Systemic and Local Antibody Responses to Infectious Bronchitis Virus in Chickens Inoculated with Infectious Bursal Disease Virus and Control Chickens

1997 ◽  
Vol 41 (3) ◽  
pp. 519 ◽  
Author(s):  
Gertrude Thompson ◽  
Hussni Mohammed ◽  
Beverly Bauman ◽  
Syed Naqi
2004 ◽  
Vol 78 (18) ◽  
pp. 10054-10063 ◽  
Author(s):  
Zhuhui Huang ◽  
Subbiah Elankumaran ◽  
Abdul S. Yunus ◽  
Siba K. Samal

ABSTRACT Infectious bursal disease virus (IBDV) causes a highly immunosuppressive disease in chickens. Currently available, live IBDV vaccines can lead to generation of variant viruses. We have developed an alternative vaccine that will not create variant IBDV. By using the reverse genetics approach, we devised a recombinant Newcastle disease virus (NDV) vector from a commonly used vaccine strain LaSota to express the host-protective immunogen VP2 of a variant IBDV strain GLS-5. The gene encoding the VP2 protein of the IBDV was inserted into the most 3′-proximal locus of a full-length NDV cDNA for high-level expression. We successfully recovered the recombinant virus, rLaSota/VP2. The rLaSota/VP2 was genetically stable, at least up to 12 serial passages in chicken embryos, and was shown to express the VP2 protein. The VP2 protein was not incorporated into the virions of recombinant virus. Recombinant rLaSota/VP2 replicated to a titer similar to that of parental NDV strain LaSota in chicken embryos and cell cultures. To assess protective efficacy of the rLaSota/VP2, 2-day-old specific-pathogen-free chickens were vaccinated with the recombinant virus and challenged with a highly virulent NDV strain Texas GB or IBDV variant strain GLS-5 at 3 weeks postvaccination. Vaccination with rLaSota/VP2 generated antibody responses against both NDV and IBDV and provided 90% protection against NDV and IBDV. Booster immunization induced higher levels of antibody responses against both NDV and IBDV and conferred complete protection against both viruses. These results indicate that the recombinant NDV can be used as a vaccine vector for other avian pathogens.


2021 ◽  
Author(s):  
Charifa DRISSI TOUZANI ◽  
Imane MAAROUFI ◽  
Siham FELLAHI ◽  
Ikhlass EL BERBRI ◽  
Fatima-zohra SIKHT ◽  
...  

Abstract The aim of the current study is to evaluate the pathogenicity of recent infectious bursal disease virus (IBDV) (1/chicken/Morocco/IB19/2017) genetically characterized as vvIBDV belonging to genogroup 3.Two chicken lines, broiler and specific-pathogen-free (SPF) chickens, were inoculated by occulonasal route with 0.2 ml of the 105EID50 /ml of viral solution of IB19 vvIBDV strain at 29 days of age. The experimental monitoring was carried out during 10 days post challenge (dpc). The clinical signs stared on day 2 pc with maximum severity observed between 3 and 6 dpc. The total mortality rate reached 10% in broilers (group G1) and 93% in SPF (G3). The macroscopic lesions in broilers G1 was a marked hypertrophy of the bursa of Fabricius (BF) with slight haemorrhage observed between 2 to 4 dpc, followed by very pronounced atrophy observed on the 5 dpc. The post-mortem examinations of dead SPF birds (G3) revealed on 3 dpc very haemorrhagic BF with black cherry appearance in 80 % of dead birds. The mean Bursa/Body Index (BBI) of challenged broilers (G1) showed a decrease of 46% on day 9 pc compared to broilers control group (G2) indicating bursal atrophy. The microscopic lesions found in the BF on 3 dpc consisted mainly of inflammation with severe lymphoid depletion of the follicles. The evaluation of recent vvIBDV outbreak is very important to understand its epidemiology and will contribute to the efficient prevention and control of IBD.


2021 ◽  
Vol 8 ◽  
Author(s):  
Abel B. Ekiri ◽  
Bryony Armson ◽  
Kehinde Adebowale ◽  
Isabella Endacott ◽  
Erika Galipo ◽  
...  

The growth of the poultry industry in Nigeria is constrained by major poultry diseases, despite the implementation of vaccination programs. This study aimed to assess the level of protection against Newcastle disease (ND), infectious bursal disease (IBD), and avian infectious bronchitis (IB) afforded by current vaccination schedules and characterize the circulating virus strains in commercial poultry flocks in Nigeria. A cross-sectional study was conducted on 44 commercial poultry farms in Oyo and Kano states of Nigeria. Serum and tissue samples and data on flock, clinical and vaccination records were collected on each farm. Farms were classified as being protected or not protected against ND, IBD and IB based on a defined criterion. Real-time reverse transcription polymerase chain reaction (rRT-PCR) testing was performed for each target virus on tissue samples and positive samples were sequenced. A total of 15/44 (34.1%), 35/44 (79.5%), and 1/44 (2.3%) farms were considered to be protected against ND, IBD, and IB, respectively, at the time of sampling. NDV RNA was detected on 7/44 (15.9%) farms and sequences obtained from 3/7 farms were characterized as the lentogenic strain. Infectious bursal disease virus (IBDV) RNA was detected on 16/44 (36.4%) farms tested; very virulent (vv) IBDV and non-virulent (nv) IBDV strains were both detected in 3/16 (18.8%) positive samples. Sequences of IBDV isolates were either clustered with a group of genotype 3 virulent IBDV strains or were related to vaccine strains MB and D78 strains. IBV RNA was detected on 36/44 (81.8%) farms, with variant02, Massachusetts, 4/91, and Q1 variants detected. Sequences of IBV isolates were either clustered with the vaccines strains Massachusetts M41 and H120 or were most closely related to the D274-like strains or a clade of sequences reported in Nigeria and Niger in 2006 and 2007. This study revealed that most study farms in Oyo and Kano states did not have adequate protective antibody titers against IBV and NDV and were therefore at risk of field challenge. Infectious bursal disease virus and IBV RNA were detected on farms with a history of vaccination suggesting potential vaccination failure, or that the vaccine strains used mismatch with the circulating strains and are therefore not protective.


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