Diversity of RNA viruses of three dominant tick species in North China.

Background: A wide range of bacterial pathogens have been identified in ticks, yet the diversity of viruses in ticks is largely unexplored.

Methods: Here, we used metagenomic sequencing to characterize the diverse viromes in three principal tick species associated with pathogens, , and , in North China.

Results: A total of 28 RNA viruses were identified and belonged to more than 12 viral families, including single-stranded positive-sense RNA viruses (, and ), negative-sense RNA viruses (, and others) and double-stranded RNA viruses ( and ). Of these, Dermacentor pestivirus-likevirus, Chimay-like rhabdovirus, taiga tick nigecruvirus, and Mukawa virus are presented as novel viral species, while Nuomin virus, Scapularis ixovirus, Sara tick-borne phlebovirus, Tacheng uukuvirus, and Beiji orthonairovirus had been established as human pathogens with undetermined natural circulation and pathogenicity. Other viruses include Norway mononegavirus 1, Jilin partitivirus, tick-borne tetravirus, Pico-like virus, Luteo-like virus 2, Luteo-likevirus 3, Vovk virus, Levivirus, Toti-like virus, and Solemo-like virus as well as others with unknown pathogenicity to humans and wild animals.

Conclusion: In conclusion, extensive virus diversity frequently occurs in and among the three tick species. Comparatively, ticks had been demonstrated as such a kind of host with a significantly higher diversity of viral species than those of and ticks. Our analysis supported that ticks are reservoirs for a wide range of viruses and suggested that the discovery and characterization of tick-borne viruses would have implications for viral taxonomy and provide insights into tick-transmitted viral zoonotic diseases.