Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2019

Erindi/veggspjald / Talk/poster V30

Sequence analysis of the HPR and F-gene of HPR0 isolates of ISAV in Iceland

Höfundar / Authors: Thorunn S. Bjornsdottir, Harpa M. Gunnarsdottir, Sabrina Natale, Thorbjorg Einarsdottir, Heida Sigurdardottir, Birkir T. Bragason, Sigridur Gudmundsdottir

Starfsvettvangur / Affiliations: Institute for Experimental Pathology, University of Iceland, Keldur

Kynnir / Presenter: Heiða Sigurðardóttir

Infectious salmon anemia (ISA) is a serious viral disease of Atlantic salmon (Salmo salar L.) caused by the ISA virus (ISAV) and notifiable to the World Organization for Animal Health (OIE). Virulent strains ISAV-HPRdel have deletions in a highly polymorphic region (HPR) on segment 6, whereas avirulent strains ISAV-HPR0 have none. Another suggested virulence marker is a Q266L substitution or insertion in the F-gene on segment 5. ISAV-HPRdel outbreaks have occurred geographically close to Iceland, only ISAV-HPR0 has been detected in Iceland.
Group I. 25037 samples from Atlantic salmon farmed in land-based facilities 2011-2018. Group II. 984 Atlantic salmon samples collected from rivers and sea-ranching facilities. Total RNA was extracted and ISAV was confirmed by One-step RT-qPCR. The HPR on segment 6 and the F-gene on segment 5 were amplified and sequenced.
In group I. 278 samples were ISAV positive. ISAV-HPRdel was not detected. Sequencing of 111 ISAV-HPR0 isolates showed no variation in the HPR and highest similarity to Norwegian and Faroese isolates. Preliminary sequencing results of the F-gene on segment 5 also suggest little variation. ISAV was not detected in group II.
ISAV-HPR0 positives are in low prevalence in farmed Atlantic salmon in Iceland and show high sequence homogeneity. The sequences of the Icelandic isolates are most similar to published sequences from Norway and the Faroe Islands. The information gathered for the F-gene further supports these observations.