Isolation and Characterization of a Novel Orthomyxovirus from a Bothriocroton hydrosauri Tick Removed from a Blotched Blue-Tongued Skink (Tiliqua nigrolutea) in Tasmania, Australia

Active and passive surveillance, followed by gene sequencing continues to identify a diverse range of novel bacteria, viruses and other microorganisms in ticks with the potential to cause disease in vertebrate hosts following tick bite. In this study, we describe the isolation and characterization of a novel virus from Bothriocroton hydrosauri ticks. In an attempt to isolate rickettsia the inoculation of Vero cell cultures with tick extracts led to the isolation of a virus, identified as a novel tick Orthomyxovirus by electron microscopy and gene sequencing. Transmission electron microscopic analysis revealed that B. hydrosauri tick virus-1 (BHTV-1) is a spherical orthomyxovirus, 85 nm in size. Multiple developmental stages of the virus were evident in vitro. Analysis of putative BHTV-1 amino acid sequences derived from genomic analysis of virus-infected host cell extracts revealed the presence of six putative RNA segments encoding genes, sharing closest sequence similarity to viral sequences belonging to arthropod-borne Thogotovirus genus within the Orthomyxoviridae. Thogotoviruses are an emerging cause of disease in humans and animals following tick bite. The detection of this new thogotovirus, BHTV-1, in B. hydrosauri, a competent vector for human tick-borne infectious diseases, warrants follow-up investigation to determine its prevalence, host range and pathogenic potential.