Characterization of novel, pathogenic field strains of infectious bronchitis virus (IBV) in poultry in Trinidad and Tobago
Autor: | Gianpiero Zamperin, Adelaide Milani, Isabella Monne, Christopher A. L. Oura, Gabriel Brown, Christine V.F. Carrington, Alice Fusaro, Arianne Brown Jordan, Lemar Blake |
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Rok vydání: | 2020 |
Předmět: |
Turkeys
animal structures Lineage (genetic) 040301 veterinary sciences Infectious bronchitis virus Biology Recombinant virus Quail Virus 0403 veterinary science 03 medical and health sciences Geese Animals Respiratory Tract Infections Phylogeny Poultry Diseases 030304 developmental biology 0303 health sciences General Veterinary General Immunology and Microbiology Phylogenetic tree Sequence Analysis RNA Vaccination Outbreak Viral Vaccines 04 agricultural and veterinary sciences General Medicine Virology Ducks Trinidad and Tobago Turkey coronavirus embryonic structures RNA Viral Coronavirus Infections Chickens |
Zdroj: | Transboundary and Emerging Diseases. 67:2775-2788 |
ISSN: | 1865-1682 1865-1674 |
Popis: | Avian coronaviruses, including infectious bronchitis virus (IBV) and turkey coronavirus (TCoV), are economically important viruses affecting poultry worldwide. IBV is responsible for causing severe losses to the commercial poultry sector globally. The objectives of this study were to identify the viruses that were causing outbreaks of severe respiratory disease in chickens in Trinidad and Tobago (TT) and to characterize the strains. Swab samples were collected from birds showing severe respiratory signs in five farms on the island of Trinidad. Samples were tested for the presence of IBV, as well as avian influenza virus (AIV), Newcastle disease virus (NDV) and avian metapneumovirus (aMPV) by real-time reverse transcription polymerase chain reaction (qRT-PCR). All samples from the five farms tested negative for AIV, NDV and aMPV; however, samples from clinically affected birds in all five of the farms tested positive for IBV. Genetic data revealed the presence of TCoV in chickens on two of the farms. Interestingly, these two farms had never reared turkeys. Phylogenetic analysis showed that IBV S1 sequences formed two distinct clusters. Two sequences grouped with vaccine strains within the GI-1 lineage, whereas three sequences grouped together, but separately from other defined lineages, forming a likely new lineage of IBV. Pairwise comparison revealed that the three unique variant strains within the distinct lineage of IBV were significantly different in their S1 nucleotide coding regions from viruses in the closest lineage (16% difference) and locally used vaccine strains (20% difference). Results also suggested that one of the samples was a recombinant virus, generated from a recombination event between a Trinidad virus of the GI-1 lineage and a Trinidad virus of the newly defined lineage. Many amino acid differences were also observed between the S1 coding regions of the circulating field and vaccine strains, indicating that the IBV vaccines may not be protective. Vaccine-challenge studies are however needed to prove this. |
Databáze: | OpenAIRE |
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