Abstract
Since 1999, 11 serotypes of bluetongue virus (BTV) similar to Central American or Caribbean strains have been isolated in the southeastern United States, predominantly in Florida. The majority of the incursive serotypes have remained restricted to the southeastern US. In recent years, BTV serotype 3 (BTV-3) has been isolated in areas increasingly distant from Florida. The current study uses whole genome sequencing of recent and historical BTV-3 isolates from the US, Central America and the Caribbean with additional sequences from GenBank to conduct phylogenetic analyses. The individual segments of the BTV genome were analysed to determine if recent BTV-3 isolates are reassortants containing genomic segments from endemic US serotypes or if they retain a majority of Central American/Caribbean genotypes. The analyses indicate that BTV-3 isolates Mississippi 2006, Arkansas 2008 and Mississippi 2009 are closely related reassortants that contain five to six genomic segments that are of US origin and two to three segments of Central American/Caribbean origin. In contrast, the BTV-3 South Dakota 2012 isolate contains seven genomic segments that are more similar to isolates from Central American and the Caribbean. These different evolutionary histories of the BTV-3 isolates suggest that there are at least two different lineages of BTV-3 that are currently circulating in the US.
Highlights
Bluetongue virus (BTV) is a non-enveloped, doublestranded RNA virus in the genus Orbivirus, family Reoviridae
The current study uses whole genome sequencing and phylogenetic analyses of recent and historical isolates from the US, Central America and the Caribbean to determine if recent US BTV serotype 3 (BTV-3) isolates are reassortants with endemic US serotypes or if they retain a Central American/Caribbean signature
The analyses show that BTV-3 isolates from Mississippi 2006, Arkansas 2008 and Mississippi 2009 have very similar evolutionary histories that have resulted in the acquisition of a majority of genomic segments of US endemic serotype origin
Summary
Bluetongue virus (BTV) is a non-enveloped, doublestranded RNA virus in the genus Orbivirus, family Reoviridae. The genome consists of ten segments that encode the seven structural (VP1-VP7) and four non-structural proteins (NS1, NS2, NS3/3a). The structural proteins are arranged in three layers comprising the outer capsid (VP2, VP5), the capsid (VP3, VP7) and the inner core (VP1, VP4, VP6) that surround the genomic RNA [1]. The non-structural proteins are responsible for cellular effects such as tubule and viral inclusion body formation (NS1 and NS2 respectively) and viral egress (NS3/3a) [1]. Bluetongue virus is transmitted by several species of biting midge of the genus Culicoides [2, 3]. BTV is the etiological agent of bluetongue disease (BTD), an economically important disease of domestic and wild ruminants. Impacts of BTD on the livestock industry are not limited to the production losses associated with the mortality/morbidity of BTD and include international restrictions on the trade of animals from areas with BTD or specific BTV serotypes [4, 5]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
