|GORAICHUK, IRYNA - Consultant|
|DAVIS, JAMES - Georgia Poultry Laboratory Network|
|KULKARNI, ARUN - Georgia Poultry Laboratory Network|
Submitted to: Microbiology Resource Announcements
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/8/2020
Publication Date: 2/27/2020
Citation: Goraichuk, I.V., Davis, J.F., Kulkarni, A.B., Afonso, C.L., Suarez, D.L. 2020. A 25-year-old sample contributes the complete genome sequence of avian coronavirus vaccine strain ArkDPI, reisolated from commercial broilers in the United States. Microbiology Resource Announcements. 9(9):e00067-20. https://doi.org/10.1128/MRA.00067-20.
Interpretive Summary: Avian coronavirus infectious bronchitis virus (IBV) (family Coronaviridae, genus Gammacoronavirus) is a respiratory pathogen that causes severe economic losses in the poultry industry worldwide. Coronaviruses display high mutation rates, like most RNA viruses, but it also has genetic recombination to increase viral variability. IBV genetic diversity is mainly monitored by analysis of the Spike 1 (S1) gene, which is the protein most involved in protection through vaccination. Numerous IBV variants have been reported in the United States. However, the Arkansas-type (Ark) is one of the most common IBV serotypes isolated from chickens in the field. Currently, only Arkansas Delmarva Poultry Industry (ArkDPI) attenuated live vaccine is commercially available against the Ark IBV serotype. It has been shown that the ArkDPI vaccine can persist in the flock causing a rolling reaction by continuing transmission of the vaccine virus among birds. Consequently, there is a need for complete genome sequencing of re-isolated vaccine viruses, so that other areas of the genome can be also analyzed for the recombination which may enhance the virus fitness in chickens. In this study, we report the first complete genome of ArkDPI vaccine virus re-isolated from chickens in the United States. In an effort to characterize this strain, sequence analysis was performed on the complete genome. Despite the ArkDPI vaccine persisting in the US flocks, there are only sequences of spike S1 gene available, but no full genomes. This study provides the first complete genome sequence for this particular strain of virus. This complete genome sequence information would be useful for in-depth understanding of the role live vaccines play in the evolution of IBVs, as well as planning vaccination strategies.
Technical Abstract: Here, we report the complete genome sequence of Avian coronavirus strain ArkDPI of the GI-9 lineage, isolated from broiler chickens in North Georgia in 1994. This is the complete genome sequence of this vaccine strain, reisolated from broilers in the United States.