Tick virome diversity in Hubei Province, China, and the influence of host ecology

Ticks are important vector hosts of pathogens which cause human and animal diseases worldwide. Diverse viruses have been discovered in ticks; however, little is known about the ecological factors that affect the tick virome composition and evolution. Herein, we employed RNA sequencing to study the virome diversity of the Haemaphysalis longicornis and Rhipicephalus microplus ticks sampled in Hubei Province in China. Twelve RNA viruses with complete genomes were identified, which belonged to six viral families: Flaviviridae, Matonaviridae, Peribunyaviridae, Nairoviridae, Phenuiviridae, and Rhabdoviridae. These viruses showed great diversity in their genome organization and evolution, four of which were proposed to be novel species. The virome diversity and abundance of R. microplus ticks fed on cattle were evidently high. Further ecological analyses suggested that host species and feeding status may be key factors affecting the tick virome structure. This study described a number of novel viral species and variants from ticks and, more importantly, provided insights into the ecological factors shaping the virome structures of ticks, although it clearly warrants further investigation.