A new Aura virus isolate in Brazil shows segment duplication in the variable region of the nsP3 gene

Ana Luiza Pamplona Mosimann,Mirian Krystel De Siqueira,Claudia Nunes Duarte Dos Santos,Ligia Fernanda Ceole

doi:10.1186/s13071-018-2907-4

Ana Luiza Pamplona Mosimann, Mirian Krystel De Siqueira + Show 2 more

Open Access

https://doi.org/10.1186/s13071-018-2907-4

Copy DOI

Abstract

BackgroundA new isolate of Aura virus serendipitously discovered as a cell culture contaminant is reported in this manuscript. Aura virus belongs to the family Togaviridae and is classified in the genus Alphavirus. There are only two reports of Aura virus isolation from mosquitoes in the scientific literature, and the existence of a vertebrate host is still unknown. The discovery of this new isolate was based on transmission electron microscopy and nucleic acid amplification through a non-specific RT-PCR amplification protocol followed by sequencing.ResultsGenetic analysis has shown that the new virus shares a high degree of identity with the previously described isolate (GenBank: AF126284.1). A major difference was observed in the nsP3 gene in which a 234-nucleotide duplication has been identified. Furthermore, a pronounced difference was observed in cell cultures compared to the data available for the previously described isolate. Cell permissiveness and phenotypic characteristics in C6/36, Vero and BHK-21 cells were found to differ from previous reports. This may be due to the genetic differences that have been observed.ConclusionsThe genetic and biological characteristics of the new Aura virus isolate are suggestive of viral adaptation to the cell substrate. The development of a cDNA clone will lend a perspective and better understanding of these results as well as open avenues for its use as a biotechnological tool, as seen for other alphaviruses.

Highlights

A new isolate of Aura virus serendipitously discovered as a cell culture contaminant is reported in this manuscript
Most alphaviruses are arthropod-borne viruses that are involved in the etiology of human viral diseases whose main symptoms are rash, fever and arthralgia (Chikungunya virus, Mayaro virus, Ross River virus, and O’nyong-nyong virus) or encephalitis (Western equine encephalitis virus, Eastern equine encephalitis virus and Venezuelan equine encephalitis virus) [1]
Rümenapf et al [14] had previously shown that BHK-21 clone 15, Vero, primary chicken embryo fibroblasts (CEF) and C6/36 cells were permissive to Aura virus (AURAV) infection

Summary

Introduction

A new isolate of Aura virus serendipitously discovered as a cell culture contaminant is reported in this manuscript. There are only two reports of Aura virus isolation from mosquitoes in the scientific literature, and the existence of a vertebrate host is still unknown. The discovery of this new isolate was based on transmission electron microscopy and nucleic acid amplification through a non-specific RT-PCR amplification protocol followed by sequencing. Despite being a virus that seems to be restricted to mosquitoes, it is not considered an insect-specific virus according to Bolling et al [6] It does not possess a known vertebrate host; to date, it is considered non-pathogenic to humans [3]. Initial hemagglutination inhibition and complement fixation studies indicate that this virus is more closely related to Western equine encephalitis virus (WEEV) and Mosimann et al Parasites & Vectors (2018) 11:321

Methods

Results

Discussion

Conclusion