Mesoniviridae: a proposed new family in the order Nidovirales formed by a single species of mosquito-borne viruses

Chris Lauber,Kouichi Morita,Eric J Snijder,Alexander E Gorbalenya,John Ziebuhr,Sandra Junglen,Florian Zirkel,Phan Thi Nga,Christian Drosten

doi:10.1007/s00705-012-1295-x

Abstract

Recently, two independent surveillance studies in Côte d’Ivoire and Vietnam, respectively, led to the discovery of two mosquito-borne viruses, Cavally virus and Nam Dinh virus, with genome and proteome properties typical for viruses of the order Nidovirales. Using a state-of-the-art approach, we show that the two insect nidoviruses are (i) sufficiently different from other nidoviruses to represent a new virus family, and (ii) related to each other closely enough to be placed in the same virus species. We propose to name this new family Mesoniviridae. Meso is derived from the Greek word “mesos” (in English “in the middle”) and refers to the distinctive genome size of these insect nidoviruses, which is intermediate between that of the families Arteriviridae and Coronaviridae, while ni is an abbreviation for “nido”. A taxonomic proposal to establish the new family Mesoniviridae, genus Alphamesonivirus, and species Alphamesonivirus 1 has been approved for consideration by the Executive Committee of the ICTV.

Highlights

Two independent surveillance studies in Cote d’Ivoire and Vietnam, respectively, led to the discovery of two mosquito-borne viruses, Cavally virus and Nam Dinh virus, with genome and proteome properties typical for viruses of the order Nidovirales
Nam Dinh virus (NDiV) was isolated from Culex vishnui, which is endemic to Asia, and Culex tritaeniorhynchus, which circulates in Asia and Africa [6], and there are indications that it may infect more mosquito species (Nga, unpublished data)
The two viruses were found to encode key molecular markers characteristic of all nidoviruses: a 3C-like main protease (3CLpro, known as Mpro) flanked by two transmembrane domains encoded in replicase ORF1a, as well as an RNAdependent RNA polymerase (RdRp) and a combination of a Zn-binding module (Zm) fused with a superfamily 1 helicase (HEL1) encoded in ORF1b

Summary

Introduction

Two independent surveillance studies in Cote d’Ivoire and Vietnam, respectively, led to the discovery of two mosquito-borne viruses, Cavally virus and Nam Dinh virus, with genome and proteome properties typical for viruses of the order Nidovirales. A taxonomic proposal to establish the new family Mesoniviridae, genus Alphamesonivirus, and species Alphamesonivirus 1 has been approved for consideration by the Executive Committee of the ICTV. Two closely related viruses, Cavally virus (CAVV) and Nam Dinh virus (NDiV), were discovered by two independent groups of researchers in Cote d’Ivoire in 2004 and in Vietnam in 2002, respectively [6, 7].

Results

Conclusion