ABSTRACT
The Mesoniviridae are a newly assigned family of viruses in the order Nidovirales. Unlike other nidoviruses, which include the Coronaviridae, mesoniviruses are restricted to mosquito hosts and do not infect vertebrate cells. To date there is little information on the morphological and antigenic characteristics of this new group of viruses and a dearth of mesonivirus-specific research tools. In this study we determined the genetic relationships of recent Australian isolates of Alphamesonivirus 4 (Casuarina virus-CASV) and Alphamesonivirus 1 (Nam Dinh virus-NDiV), obtained from multiple mosquito species. Australian isolates of NDiV showed high-level similarity to the prototype NDiV isolate from Vietnam (99% nucleotide (nt) and amino acid (aa) identity). Isolates of CASV from Central Queensland were genetically very similar to the prototype virus from Darwin (95-96% nt and 91-92% aa identity). Electron microscopy studies demonstrated that virion diameter (≈80 nm) and spike length (≈10 nm) were similar for both viruses. Monoclonal antibodies specific to CASV and NDiV revealed a close antigenic relationship between the two viruses with 13/34 mAbs recognising both viruses. We also detected NDiV RNA on honey-soaked nucleic acid preservation cards fed on by wild mosquitoes supporting a possible mechanism of horizontal transmission between insects in nature.
Subject(s)
Antigens, Viral/immunology , Culicidae/virology , Disease Transmission, Infectious , Nidovirales/genetics , Nidovirales/immunology , Animals , Australia , Nidovirales/classification , Phylogeny , Sequence Analysis, DNA , Vietnam , VirionABSTRACT
The complete genome sequences of two Barmah Forest virus (BFV) strains isolated from mosquitoes trapped in the Australian Defence Force (ADF) training areas during 2017 and 2018 reveal multiple nucleotide insertions in the 3' untranslated region (UTR) of ADF BFV strains compared with the BFV prototype strain whole-genome sequence in GenBank.
ABSTRACT
The complete genome sequences of three Ross River virus (RRV) isolates from infected Australian Defence Force (ADF) personnel and from mosquitoes collected in ADF training areas were determined. Phylogenetic analysis in comparison with all available complete RRV nucleotide sequences from GenBank split these three RRV isolates into two distinct sublineages.
ABSTRACT
This report describes the near complete genomic sequence and subsequent analysis of Vinegar Hill virus (VINHV; tentative member of the genus Orthonairovirus, family Nairoviridae, order Bunyavirales). VINHV is the second nairovirus reported to be isolated on mainland Australia and the first to be sequenced and analysed. Our genetic analysis shows that VINHV belongs to the Dera Ghazi Khan genogroup, a group of viruses previously isolated in other parts of the world including Asia, South Africa, and the USA. We discuss possible routes of entry for nairoviruses into Australia and the need to understand the virome of Australian ticks in the context of new and emerging disease.
Subject(s)
Genome, Viral , Nairovirus/genetics , Animals , Australia , Nairovirus/classification , Nairovirus/isolation & purification , Phylogeny , Sequence Analysis, DNA , Sequence Homology , Ticks/virologySubject(s)
Bunyaviridae Infections/veterinary , Phlebovirus/pathogenicity , Ticks/virology , Animals , Australia/epidemiology , Bird Diseases/epidemiology , Bird Diseases/genetics , Birds/genetics , Birds/virology , Bunyaviridae Infections/epidemiology , Humans , Phlebovirus/genetics , Phylogeny , Ticks/geneticsABSTRACT
The Mapputta serogroup tentatively contains the mosquito-associated viruses Mapputta, Maprik, Trubanaman and Gan Gan. Interestingly, this serogroup has previously been associated with an acute epidemic polyarthritis-like illness in humans; however, there has been no ensuing genetic characterisation. Here we report the complete genome sequences of Mapputta and Maprik viruses, and a new Mapputta group candidate, Buffalo Creek virus, previously isolated from mosquitoes and detected by serology in a hospitalised patient. Phylogenetic analyses indicate that the group is one of the earliest diverged groups within the genus Orthobunyavirus of the family Bunyaviridae. Analyses show that these three viruses are related to the recently sequenced Australian bunyaviruses from mosquitoes, Salt Ash and Murrumbidgee. A notable feature of the Mapputta group viruses is the absence of the NSs (non-structural) ORF commonly found on the S segment of other orthobunyaviruses. Viruses of the Mapputta group have been isolated from geographically diverse regions ranging from tropical Papua New Guinea to the semi-arid climate of south-eastern Australia. The relevance of this group to human health in the region merits further investigation.
Subject(s)
Bunyaviridae Infections/virology , Genome, Viral/genetics , Orthobunyavirus/genetics , Amino Acid Sequence , Animals , Culicidae/virology , Genomics/methods , Humans , Papua New Guinea , Phylogeny , Sequence Analysis, DNA/methods , Serogroup , South AustraliaABSTRACT
DNA vaccines encoding different portions of the structural proteins of western equine encephalitis virus were tested for the efficacy of their protection in a 100% lethal mouse model of the virus. The 6K-E1 structural protein encoded by the DNA vaccine conferred complete protection against challenge with the homologous strain and limited protection against challenge with a heterologous strain.
