Novel orbivirus in Amblyomma tholloni ticks parasitizing African savanna elephants (Loxodonta africana) in Zambia

Abstract

Orbiviruses are emerging pathogens of public and veterinary health concern. This study reports the discovery and genomic characterization of a novel orbivirus in adult ticks collected from African savanna elephants (Loxodonta africana) in Kafue National Park, Zambia. Six ticks were identified through genetic analyses; one Rhipicephalus maculatus and five Amblyomma tholloni. Salivary gland and blood meal samples were dissected for virus characterization. Total nucleic acids were extracted and reverse-transcribed, and libraries were prepared for deep sequencing. De novo assembly of trimmed sequences recovered four novel viruses designated "zaloxo" to indicate their association with Zambian elephants (genus Loxodonta), abbreviated ZXLV-1 to ZXLV-4. ZXLV-1, a member of the genus Orbivirus, belongs to the same subclade of dsRNA orbiviruses as bluetongue virus, epizootic hemorrhagic disease virus, and African horse sickness virus. ZXLV-2 and ZXLV-3 are most closely related to dsRNA Totiviridae and ssDNA Circoviridae viruses, respectively. ZXLV-4 belongs to the genus Alphapolyomavirus, dsDNA viruses which are ubiquitous in mammals but have unclear associations with disease. While the pathogenicity of these viruses remains unclear, these results suggest that a hidden diversity of viruses likely exists in elephant ectoparasites, warranting attention from the perspective of both health and conservation.

Keywords: Arbovirus; Kafue National Park; Tick-borne virus; Viral discovery.