Paramushir virus belongs to Sakhalin virus genogroup within Orthonairovirus genus and is one of the poorly studied viruses with unknown pathogenicity. At the moment, only one nearly complete sequence of
Paramushir virus genome, isolated in 1972, is available. Two new strains of
PARV were isolated in 2015 from a sample collected at the Tyuleniy Island in
the Okhotsk Sea and sequenced using a combination of high throughput sequencing and specific multiplex PCR. Both strains are closely related to the early sequenced PARV strain LEIV–1149 K. The signs of intersegment reassortment and probable recombination were revealed, which point to a high variability
potential of Paramushir virus and may lead to the formation of strains with
novel properties, different from those of the predecessors. The new data regarding Paramushir virus can promote a better understanding of
the diversity and relations within Orthonairovirus genus and help define intragenic demarcation criteria, which have not yet been established.