Factors influencing the outcome of infectious bronchitis vaccination and challenge experiments

Wit, Janneke; Cook, Jane K.A.

doi:10.1080/03079457.2014.974504

Cited by 52 publications

(42 citation statements)

References 98 publications

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“…IB still causes serious problems in the Iraqi poultry industry due to the inability of the vaccines to provide cross-protection between different genotypes [1]. The genotyping of IBV is necessary not only for understanding virus evolution but also for effective modification of the vaccination programs [10]. In this study, the infection rate of IBV was 32 %, which indicated widespread distribution of IBV in the southern and middle parts of Iraq.…”

Section: Discussionmentioning

confidence: 66%

Genotyping of infectious bronchitis viruses from broiler farms in Iraq during 2014-2015

et al. 2016

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Infectious bronchitis virus (IBV) is one of the most critical pathogens in the poultry industry, causing serious economic losses in all countries including Iraq. IBV has many genotypes that do not confer any cross-protection. This virus has been genotyped by sequence analysis of the S1 glycoprotein gene. A total of 100 tracheal and kidney tissue specimens from different commercial broiler flocks in the middle and south of Iraq were collected from September 2013 to September 2014. Thirty-two IBV-positive samples were selected from among the total and were further characterized by nested PCR. Phylogenetic analysis revealed that isolates belong to four groups (group I, variant 2 [IS/1494-like]; group II, 793/B-like; group III, QX-like; group IV, DY12-2-like). Sequence analysis revealed nucleotide sequence identities within groups I, II, and III of 99.68 %-100 %, 99.36 %-100 %, and 96.42 %-100 %, respectively. Group I (variant 2) was the dominant IBV genotype. One Chinese-like recombinant virus (DY12-2-like) that had not been reported in the Middle East was detected. In addition, the presence of QX on broiler chicken farms in the area studied was confirmed. This is the first comprehensive study on the genotyping of IBV in Iraq with useful information regarding the molecular epidemiology of IBV. The phylogenetic relationship of the strains with respect to different time sequences and geographical regions displayed complexity and diversity. Further studies are needed and should include the isolation and full-length molecular characterization of IBV in this region.

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Section: Discussionmentioning

confidence: 66%

Genotyping of infectious bronchitis viruses from broiler farms in Iraq during 2014-2015

et al. 2016

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“…Clinical respiratory symptoms in both groups were mild, but comparable (not shown). As the severity of IBV clinical symptoms also relies on environmental factors, including but not limited to cold and heat stress, food additives and the presence of secondary bacterial or viral infections [22], the severity of clinical symptoms in an experimental setting is often less than in the field [23,24].…”

Section: Discussionmentioning

confidence: 99%

Attenuated live infectious bronchitis virus QX vaccine disseminates slowly to target organs distant from the site of inoculation

Laconi

Weerts

Bloodgood

et al. 2020

Vaccine

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a b s t r a c tInfectious bronchitis (IB) is a highly contagious respiratory disease of poultry, caused by the avian coronavirus infectious bronchitis virus (IBV). Currently, one of the most relevant genotypes circulating worldwide is IBV-QX (GI-19), for which vaccines have been developed by passaging virulent QX strains in embryonated chicken eggs. Here we explored the attenuated phenotype of a commercially available QX live vaccine, IB Primo QX, in specific pathogens free broilers. At hatch, birds were inoculated with QX vaccine or its virulent progenitor IBV-D388, and postmortem swabs and tissues were collected each day up to eight days post infection to assess viral replication and morphological changes. In the trachea, viral RNA replication and protein expression were comparable in both groups. Both viruses induced morphologically comparable lesions in the trachea, albeit with a short delay in the vaccinated birds. In contrast, in the kidney, QX vaccine viral RNA was nearly absent, which coincided with the lack of any morphological changes in this organ. This was in contrast to high viral RNA titers and abundant lesions in the kidney after IBV D388 infection. Furthermore, QX vaccine showed reduced ability to reach and replicate in conjunctivae and intestines including cloaca, resulting in significantly lower titers and delayed protein expression, respectively. Nephropathogenic IBVs might reach the kidney also via an ascending route from the cloaca, based on our observation that viral RNA was detected in the cloaca one day before detection in the kidney. In the kidney distal tubular segments, collecting ducts and ureter were positive for viral antigen. Taken together, the attenuated phenotype of QX vaccine seems to rely on slower dissemination and lower replication in target tissues other than the site of inoculation.

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“…Currently, the most effective control measure is vaccine application, which proved to effectively reduce clinical signs emergence, infectious pressure and viral population size, at least when properly performed 4,5 . However, this approach cannot be considered a panacea, and some drawbacks cannot be denied.…”

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confidence: 99%

Phylodynamic analysis and evaluation of the balance between anthropic and environmental factors affecting IBV spreading among Italian poultry farms

Franzo

Tucciarone

Moreno

et al. 2020

Sci Rep

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Infectious bronchitis virus (IBV) control is mainly based on wide vaccine administration.Although effective, its efficacy is not absolute, the viral circulation is not prevented and some side effects cannot be denied. Despite this, the determinants of IBV epidemiology and the factors affecting its circulation are still largely unknown and poorly investigated. In the present study, 361 IBV QX (the most relevant field genotype in Italy) sequences were obtained between 2012 and 2016 from the two main Italian integrated poultry companies. Several biostatistical and bioinformatics approaches were used to reconstruct the history of the QX genotype in Italy and to assess the effect of different environmental, climatic and social factors on its spreading patterns. Moreover, two structured coalescent models were considered in order to investigate if an actual compartmentalization occurs between the two integrated poultry companies and the role of a third "ghost" deme, representative of minor industrial poultry companies and the rural sector. The obtained results suggest that the integration of the poultry companies is an effective barrier against IBV spreading, since the strains sampled from the two companies formed two essentially-independent clades. Remarkably, the only exceptions were represented by farms located in the high densely populated poultry area of Northern Italy. The inclusion of a third deme in the model revealed the likely role of other poultry companies and rural farms (particularly concentrated in Northern Italy) as sources of strain introduction into one of the major poultry companies, whose farms are mainly located in the high densely populated poultry area of Northern Italy. Accordingly, when the effect of different environmental and urban parameters on IBV geographic spreading was investigated, no factor seems to contribute to IBV dispersal velocity, being poultry population density the only exception. Finally, the different viral population pattern observed in the two companies over the same time period supports the pivotal role of management and control strategies on IBV epidemiology. Overall, the present study results stress the crucial relevance of human action rather than environmental factors, highlighting the direct benefits that could derive from improved management and organization of the poultry sector on a larger scale. Infectious bronchitis virus (IBV)is currently classified in the species Avian coronavirus, genus Gammacoronavirus, family Coronaviridae (https://talk.ictvonline.org/). The viral genome is about 27Kb long and encodes different non-structural, accessory and structural proteins. Among those, the structural spike protein is by far the most extensively studied, because of its role in viral attachment, cell tropism and immunity 1 . Additionally, the current

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Factors influencing the outcome of infectious bronchitis vaccination and challenge experiments

Cited by 52 publications

References 98 publications

Genotyping of infectious bronchitis viruses from broiler farms in Iraq during 2014-2015

Genotyping of infectious bronchitis viruses from broiler farms in Iraq during 2014-2015

Attenuated live infectious bronchitis virus QX vaccine disseminates slowly to target organs distant from the site of inoculation

Phylodynamic analysis and evaluation of the balance between anthropic and environmental factors affecting IBV spreading among Italian poultry farms

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