Complete genome sequence and evolution analysis of Eimeria stiedai RNA virus 1, a novel member of the family Totiviridae

Eimeria stiedai (E. stiedai) is a coccidian that infects the liver of the domestic rabbit and may cause severe hepatic coccidiosis. Virus-like particles in E. stiedai were discovered by Revets et al. However, the complete genome sequence of the E. stiedai virus has yet to be determined. A novel virus was isolated from E. stiedai in the present study. The complete genome sequence of the E. stiedai virus was 6219 bp in length and contained two open reading frames (ORFs) with a tetranucleotide overlap (AUGA). ORF1 (2400 bp) encoded a putative coat protein of 799 amino acids (86.471 kDa) that exhibited a high level of amino acid sequence similarity to that of Eimeria tenella (E. tenella) RNA virus 1 (EtRV1; 43 % identity, NC_026140), whereas ORF2 (3303 bp) encoded a putative RNA-dependent RNA polymerase (RdRp) of 1100 amino acids (118.850 kDa) that exhibited a high level of amino acid sequence similarity to that of the E. tenella RNA virus 1 (EtRV1; 51 % identity, NC_026140). Phylogenetic analysis revealed that the E. stiedai virus was a new member of the family Totiviridae. The sequence data provided sufficient information for classification of eimeriaviruses.