Betacoronavirus

Betacoronaviruses are one of four genera of coronaviruses of the subfamily Orthocoronavirinae in the family Coronaviridae, of the order Nidovirales. They are enveloped, positive-sense, single-stranded RNA viruses of zoonotic origin. The coronavirus genera are each composed of varying viral lineages with the betacoronavirus genus containing four such lineages. Betacoronaviruses are one of four genera of coronaviruses of the subfamily Orthocoronavirinae in the family Coronaviridae, of the order Nidovirales. They are enveloped, positive-sense, single-stranded RNA viruses of zoonotic origin. The coronavirus genera are each composed of varying viral lineages with the betacoronavirus genus containing four such lineages. The Beta-CoVs of the greatest clinical importance concerning humans are OC43, and HKU1 of the A lineage, SARS-CoV of the B lineage, and MERS-CoV of the C lineage. MERS-CoV is the first betacoronavirus belonging to lineage C that is known to infect humans. The alpha- and beta-coronavirus genera descend from the bat gene pool. SARS-CoV virus causes SARS disease, and MERS-CoV virus causes Middle East respiratory syndrome (MERS) disease. Coronaviruses have a large genome size that ranges from 26 to 32 kilobases. As of May 2013, GenBank has 46 published complete genomes of the α-(group 1), β-(group 2), γ-(group 3), and δ-(group 4) CoVs.