Koolpinyah and Yata viruses: Two newly recognised ephemeroviruses from tropical regions of Australia and Africa

•Koolpinyah and Yata viruses are rhabdoviruses isolated from cattle and mosquitoes.•We determine the complete genome sequences of these poorly characterised viruses.•We show that they have similar genome structure and sequence to bovine ephemeral fever virus.•We show they cluster phylogenetically as ephemeroviruses but are distinct serologically.•Each should be classified as new ephemerovirus species of unknown pathogenic potential.

Koolpinyah virus (KOOLV) isolated from healthy Australian cattle and Yata virus (YATV) isolated from a pool of Mansonia uniformis mosquitoes in the Central African Republic have been tentatively identified as rhabdoviruses. KOOLV was shown previously to be related antigenically to kotonkon virus, an ephemerovirus that has caused an ephemeral fever-like illness in cattle in Nigeria, but YATV failed to react antigenically with any other virus tested. Here we report the complete genome sequences of KOOLV (16,133 nt) and YATV (14,479 nt). Each has a complex genome organisation, with multiple genes, including a second non-structural glycoprotein (GNS) gene and a viroporin (α1) gene, between the G and L genes as is characteristic of ephemeroviruses. Based on an analysis of genome organisation, sequence identity and cross-neutralisation, we demonstrate that both KOOLV and YATV should be classified as two new species in the genus Ephemerovirus.