St Abbs Head phlebovirus – a separate virus species or a strain of Uukuniemi phlebovirus?

St Abbs Head virus (SAHV), member of Phlebovirus genus (family Phenuiviridae, order Bunyavirales), belongs to the largest group of negative strand RNA viruses. All phleboviruses share a genome structure that comprises three segments of negative-sense or ambi-sense RNA. The viral genome is composed of the small (S), medium (M) and large (L) RNA segments. The S segment encodes the nucleocapsid (N) protein, the M segment encodes the precursor for the viral glycoproteins (Gn and Gc) and the L segment encodes the viral RNA-dependent RNA polymerase (RdRp). Some viruses within the genus also encode non-structural proteins within their S or M segments.

SAHV was isolated from a pool of Ixodes uriae ticks collected at a seabird colony in Berwickshire, Scotland in 1979. There were quite a few related bunyaviruses found in tick and bird samples on the East Coast of Scotland and England in the 70s and 80s. Recently we have sequenced a sample of SAHV using next generation sequencing technology. The results suggested that this virus is very closely related to the Uukuniemi phlebovirus (UUKV). To determine how similar are SAHV and UUKV, we compared virus growth in various mammalian, bird and tick cell lines.