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Epidemiology and immunoprotection of nephropathogenic avian infectious bronchitis virus in southern China
Qingmei Xie, Jun Ji, Jingwei Xie, Feng Chen, Manshan Cai, Baoli Sun, Chunyi Xue, Jingyun Ma, Yingzuo Bi
Virology Journal , 2011, DOI: 10.1186/1743-422x-8-484
Abstract: Based on epidemiology analysis of recent field isolates of nephropathogenic IB in vaccinated farms in China, YL6 strain were used for vaccination and evaluated by antibody titer and challenge tests. The immunoprotection test indicated that the practical application of vaccine based on the recent field strains could finely facilitate controlling the nephropathogenic IB.Our study was aim at setting a guide for safeguard against nephropathogenic IBV-caused disease in China.Infectious bronchitis (IB) is a serious and highly contagious disease of chickens all over the world. Avian infectious bronchitis virus (IBV) was first reported in the USA for replicating in the respiratory tract and some other epithelial cells of gut, kidney, and oviduct. Subsequently, some strains of IBV caused pathology in non-respiratory organs (such as kidney and gonads) were documented [1]. The clinical disease and production problems frequently cause catastrophic economic losses to the poultry industry, accompanied by decreased production performance in breeder flocks, diminished egg production and poor egg quality in laying flocks [1-3]. In China, IB has a more profound social impact for chicken industrial contributes to the rural economy. More importantly, there is accumulating evidence that nephropathogenic type IB has been more and more prevalent in China recently, but the strains isolated in earlier years mainly caused respiratory signs, which suggested that selecting and immunization with the appropriate vaccine strain is of great importance to control IB infection [4-7].Some researchers reported that satisfactory cross protection could be provided by appropriate vaccine programs against genetically or antigenically unrelated IBVs [8]. However, this symphysial vaccine manner was restricted by the diversity of the IBV strains. Since IBV strains were first isolated and identified in China in 1982, various live-attenuated and inactivated vaccines derived from respiratory-typed strains have
Serosurveillance Study on Avian Infectious Bronchitis Virus in Sudan
A.Ballal,A.E. Karrar,A.M. ElHussein
Journal of Animal and Veterinary Advances , 2012,
Abstract: Serum samples were collected from commercial layer and broiler flocks 3 to 63 weeks old at four areas from Sudan. All flocks were not previously vaccinated against infectious bronchitis (IB) virus. Sera were tested using haemagglutination inhibition (HI) test for IB virus antibodies. 689(71%) out of the 957 samples examined had an HI titer ranging from 6 to 11 (log ). High incidence (90%) of IB virus infection was detected among layer flocks at Khartoum State and 46.8% of the samples had an HI titer > 10(log ). Low HI titer (<4 log ) was detected among samples collected from layer flocks at Sennar (Central Sudan). The results obtained indicated widespread and distribution of IB virus infection in Sudan.
Avian infectious bronchitis virus in Brazil: a highly complex virus meets a highly susceptible host population
Brand?o, PE;
Revista Brasileira de Ciência Avícola , 2010, DOI: 10.1590/S1516-635X2010000200008
Abstract: infectious bronchitis (ib) is a highly aggressive disease for poultry in terms of symptoms and economic losses, and the control of this disease is difficult if flocks are not protected against type-specific challenges by the avian infectious bronchitis virus (ibv). this article summarizes data presented by the author at the workshop on infectious bronchitis 2009 on ib and ibv, including future developments on the field.
Recombination in Avian Gamma-Coronavirus Infectious Bronchitis Virus  [PDF]
Sharmi W. Thor,Deborah A. Hilt,Jessica C. Kissinger,Andrew H. Paterson,Mark W. Jackwood
Viruses , 2011, DOI: 10.3390/v3091777
Abstract: Recombination in the family Coronaviridae has been well documented and is thought to be a contributing factor in the emergence and evolution of different coronaviral genotypes as well as different species of coronavirus. However, there are limited data available on the frequency and extent of recombination in coronaviruses in nature and particularly for the avian gamma-coronaviruses where only recently the emergence of a turkey coronavirus has been attributed solely to recombination. In this study, the full-length genomes of eight avian gamma-coronavirus infectious bronchitis virus (IBV) isolates were sequenced and along with other full-length IBV genomes available from GenBank were analyzed for recombination. Evidence of recombination was found in every sequence analyzed and was distributed throughout the entire genome. Areas that have the highest occurrence of recombination are located in regions of the genome that code for nonstructural proteins 2, 3 and 16, and the structural spike glycoprotein. The extent of the recombination observed, suggests that this may be one of the principal mechanisms for generating genetic and antigenic diversity within IBV. These data indicate that reticulate evolutionary change due to recombination in IBV, likely plays a major role in the origin and adaptation of the virus leading to new genetic types and strains of the virus.
Serotypes of Avian Infectious Bronchitis Virus Isolates From Field Cases in Sudan
A. Ballal,A. M. Elhussein,A. E. Karar
Journal of Animal and Veterinary Advances , 2012,
Abstract: Infectious bronchitis (IB) virus field isolates were serotype using virus neutralization (VN) and haemagglutination inhibition (HI) tests. The viruses were isolated from an outbreaks of IB in broiler and layer chicken flocks in Sudan during 2000- 2001. Four isolates (3 from layer and 1 from breeder broiler flocks) were found antigenically similar to IB virus strain 4/91. With neutralization index (NI) 4.4 - 5.0 and VN titer = 11 (log ). 2 On the other hand, four isolates from commercial broiler flocks and one isolate from layer were found antigenically similar to IB Massachusetts Mass. serotypes with HI titer = 11 (log ). This is the first report of 2 various IB serotypes that are prevalent in Sudan.
The Replicase Gene of Avian Coronavirus Infectious Bronchitis Virus Is a Determinant of Pathogenicity  [PDF]
Maria Armesto, Dave Cavanagh, Paul Britton
PLOS ONE , 2009, DOI: 10.1371/journal.pone.0007384
Abstract: We have previously demonstrated that the replacement of the S gene from an avirulent strain (Beaudette) of infectious bronchitis virus (IBV) with an S gene from a virulent strain (M41) resulted in a recombinant virus (BeauR-M41(S)) with the in vitro cell tropism of the virulent virus but that was still avirulent. In order to investigate whether any of the other structural or accessory genes played a role in pathogenicity we have now replaced these from the Beaudette strain with those from M41. The recombinant IBV was in effect a chimaeric virus with the replicase gene derived from Beaudette and the rest of the genome from M41. This demonstrated that it is possible to exchange a large region of the IBV genome, approximately 8.4 kb, using our transient dominant selection method. Recovery of a viable recombinant IBV also demonstrated that it is possible to interchange a complete replicase gene as we had in effect replaced the M41 replicase gene with the Beaudette derived gene. Analysis of the chimaeric virus showed that it was avirulent indicating that none of the structural or accessory genes derived from a virulent isolate of IBV were able to restore virulence and that therefore, the loss of virulence associated with the Beaudette strain resides in the replicase gene.
Genetic Grouping of Nephropathogenic Avian Infectious Bronchitis Virus Isolated in Morocco  [PDF]
M. El Bouqdaoui,R.A. Mhand,H. Bouayoune,M.M. Ennaji
International Journal of Poultry Science , 2005,
Abstract: Thirty Moroccan isolates of infectious bronchitis virus (IBV) recovered from unvaccinated broiler chickens flocks originated from different regions of Morocco between 1997 and 2002, and two references strains Massachusetts and 4/91 (vaccine strains) were classified by reverse transcriptase-polymerase chain reaction (RT-PCR) and restriction fragment length polymorphism (RFLP) analysis using two restriction enzymes Hae III and Alu1. RFLP patterns of the amplified S1 gene of IBV (1720 bp) digested by two restriction enzymes HaeIII and Alu1 showed that Moroccan isolates of IBV were classified into five genotypes with Three genotypes different from vaccine strains, vaccine protection test showed that Massachusetts type vaccine could not protect chickens against challenge with this three new genotypes.
Nucleocapsid Gene Sequence Analysis and Characterization of an Indian Isolate of Avian Infectious bronchitis virus  [PDF]
Monika Kaul,Megha Kadam,Yashpal Malik,Ashok Kumar Tiwari
International Journal of Poultry Science , 2009,
Abstract: Avian Infectious bronchitis virus belongs to the family Coronaviridae. It is an enveloped virus with large positive stranded RNA genome. In the present study RNA was isolated from viral suspension and transcribed into cDNA. Poultry postmortem cases showing lesions of visceral gout were collected and infectious bronchitis virus were isolated. About 1.2 kb Nucleocapsid gene of virus was amplified by RT-PCR from four clinical samples. The amplified product was cloned and the nucleotide sequence of the N gene of an Indian field isolate was determined. The Indian IBV isolate exhibited 95% homology with Korean isolates and Chinese vaccine strains indicated conserved nature of N gene. Haemagglutination assay and chicken embryo inoculation was carried out for antigenic studies of the virus. The virus titre was confirmed using haemagglutination assay and IBVN2 showed the 1:2048+ titre. Propagation of virus was done by chorioallantoic method of inoculation of virus suspension in embryonated eggs. Characteristic curling and dwarfing of embryos was noticed in CAM inoculated embryonated eggs. Inoculated eggs showed teratogenic changes and deposition of urates as indication of naphropathogenic nature of virus.
Role of Infectious Bronchitis Live Vaccine on Pathogenicity of H9N2 Avian Influenza Virus  [PDF]
M. Haghighat-Jahromi,K. Asasi,H . Nili,H . Dadras
International Journal of Poultry Science , 2007,
Abstract: Based on experimental inoculation of chickens and sequence of amino acids at cleavage site, H9N2 AIV is pathotyped as low pathogenic avian influenza virus. But our extensive field experiences during last decade show serious disease problems and high mortality associated with this subtype in some Asian countries. One of the possible explanations for such a high mortality and great economic losses could be circulation of the virus and mixed infection with other respiratory pathogens. Infectious Bronchitis Live Vaccine (IBLV) is being used broadly in chicken farms of these countries. So it was decided to experimentally study the effect of infectious bronchitis live vaccine (H120) on enhancing of pathogenicity of H9N2 in broiler chicks. Clinical signs, gross lesions, viral shedding and mortality rate were compared between groups. Results of the present study showed that co-infection of IBLV with H9N2 AI virus not only increased the severity of H9N2 AIV clinical sings and gross lesions; but also increased the mortality rate and extended viral shedding period of H9N2 avian influenza virus.
Identification of one peptide which inhibited infectivity of avian infectious bronchitis virus in vitro
Bo Peng,Hanyang Chen,Yadi Tan,Meilin Jin,Huanchun Chen,Aizhen Guo
Science China Life Sciences , 2006, DOI: 10.1007/s11427-006-0158-7
Abstract: Purified avian infectious bronchitis virus (IBV) was used to screen a random phage display peptide library. After the fourth panning, 10 positive phages were sequenced and characterized. The phages specifically inhibited IBV infectivity in HeLa cells and blocked IBV haemagglutination. One linear peptide “GSH HRH VHS PFV” from the positive phages with the highest neutralization titer was synthesized and this peptide inhibited IBV infection in HeLa as well. The results may contribute to development of antiviral therapeutics for IBV and studying the determinants for viral and cell interaction.
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