Zahedan rhabdovirus, a novel virus detected in ticks from Iran

Abstract

BackgroundRhabdoviridae infect a wide range of vertebrates, invertebrates and plants. Their transmission can occur via various arthropod vectors. In recent years, a number of novel rhabdoviruses have been identified from various animal species, but so far only few tick-transmitted rhabdoviruses have been described.MethodsWe isolated a novel rhabdovirus, provisionally named Zahedan rhabdovirus (ZARV), from Hyalomma anatolicum anatolicum ticks collected in Iran. The full-length genome was determined using 454 next-generation sequencing and the phylogenetic relationship to other rhabdoviruses was analyzed. Inoculation experiments in mammalian Vero cells and mice were conducted and a specific PCR assay was developed.ResultsThe complete genome of ZARV has a size of 11,230 nucleotides (nt) with the typical genomic organization of Rhabdoviridae. Phylogenetic analysis confirms that ZARV is closely related to Moussa virus (MOUV) from West Africa and Long Island tick rhabdovirus (LITRV) from the U.S., all forming a new monophyletic clade, provisionally designated Zamolirhabdovirus, within the Dimarhabdovirus supergroup. The glycoprotein (G) contains 12 conserved cysteins which are specific for animal rhabdoviruses infecting fish and mammals. In addition, ZARV is able to infect mammalian Vero cells and is lethal for mice when inoculated intracerebrally or subcutaneously. The developed PCR assay can be used to specifically detect ZARV.ConclusionThe novel tick-transmitted rhabdovirus ZARV is closely related to MOUV and LITRV. All three viruses seem to form a new monophyletic clade. ZARV might be pathogenic for mammals, since it can infect Vero cells, is lethal for mice and its glycoprotein contains 12 conserved cysteins only found in animal rhabdoviruses. The mammalian host of ZARV remains to be identified.

Tick-Borne Viruses

“…According to the latest official report of ICTV in 2016, the family Rhabdoviridae can be taxonomically classified into 18 genera ( Almendravirus , Curiovirus , Cytorhabdovirus , Dichorhavirus , Ephemerovirus , Hapavirus , Ledantevirus , Lyssavirus , Novirhabdovirus , Nucleorhabdovirus , Perhabdovirus , Sigmavirus , Sprivivirus , Sripuvirus , Tibrovirus , Tupavirus , Varicosavirus , and Vesiculovirus ) and other unassigned rhabdoviruses. The virions of rhabdoviruses are characteristically bullet-shaped particles with the length of 100–430 nm and the diameter of 45–100 nm (Dilcher et al 2015 ). Rhabdoviruses are non-segmented, negative-sense RNA viruses with 11–15 kbp genomes coding for at least five transcription units: nucleoprotein (N), phosphprotein (P), matrix protein (M), glycoprotein (G) and the RNA-dependent RNA polymerase (RdRp) (King et al 2012 ).…”

“…ZARV was isolated from Hy. anatolicum ticks from Iran (Dilcher et al 2015 ). However, sequence comparisons and phylogenetic analyses do not associate LITRV and ZARV with any one of the recognized species or genera of this family, but these two viruses form a monophyletic clade with an unassigned mosquito-borne rhabdovirus from Côte d’Ivoire, which is proposed to be a unique taxonomic group within Rhabdoviridae (Tokarz et al 2014a ).…”

Tick-Borne Viruses and Biological Processes at the Tick-Host-Virus Interface

“…In recent years, further novel rhabdoviruses have been identified from various animal species, but so far transmission by ticks have been confirmed only for a few of them, e.g., Kolente virus (Ghedin et al, 2013 ) and Yongjia tick virus 2 (YTV-2) (Li et al, 2015 ). For Long Island tick rhabdovirus (Tokarz et al, 2014 ) and Zahedan virus (Dilcher et al, 2015 ) transmission by ticks has yet to be confirmed.…”

Complete study demonstrating the absence of rhabdovirus in a distinct Sf9 cell line

“…Although the assembly of RNA virus genomes from NGS data resulted in a more complete sequence for 5’-untranslated regions than the use of 5’-RACE [15][16][17]. , Liu et al [10] have pointed out that analysis of NGS data often results in identification of contigs with sequence similarity to viral sequences through BLAST, but the results may actually come from EVEs.…”

“…Recent advances in next generation sequencing (NGS) technology have enabled the discovery of covert and previously un-described insect RNA viruses [ 10 ][ 11 ][ 12 ] and metagenomic analysis has been used to identify new viruses and endogenous viral elements (EVEs) associated with economically important insects [ 13 ][ 14 ]. Although the assembly of RNA virus genomes from NGS data resulted in a more complete sequence for 5’-untranslated regions than the use of 5’-RACE [ 15 ][ 16 ][ 17 ]., Liu et al [ 10 ] have pointed out that analysis of NGS data often results in identification of contigs with sequence similarity to viral sequences through BLAST, but the results may actually come from EVEs. Unfortunately, there is no reliable way to distinguish between real viral sequences and EVEs from NGS data analysis without extensive experimentation.…”