Isolation of Nyamanini and Quaranfil Viruses from Argas (Persicargas) Arboreus Ticks in Nigeria1

Tick-borne Nyamanini virus (NYMV) is the prototypic member of a recently discovered genus in the order Mononegavirales , designated Nyavirus . The NYMV genome codes for six distinct genes. Sequence similarity and structural properties suggest that genes 1, 5, and 6 encode the nucleoprotein (N), the glycoprotein (G), and the viral polymerase (L), respectively. The function of the other viral genes has been unknown to date. We found that the third NYMV gene codes for a protein which, when coexpressed with N and L, can reconstitute viral polymerase activity, suggesting that it represents a polymerase cofactor. The second viral gene codes for a small protein that inhibits viral polymerase activity and further strongly enhances the formation of virus-like particles when coexpressed with gene 4 and the viral glycoprotein G. This suggests that two distinct proteins serve a matrix protein function in NYMV as previously described for members of the family Filoviridae . We further found that NYMV replicates in the nucleus of infected cells like members of the family Bornaviridae . NYMV is a poor inducer of beta interferon, presumably because the viral genome is 5′ monophosphorylated and has a protruding 3′ terminus as observed for bornaviruses. Taken together, our results demonstrate that NYMV possesses biological properties previously regarded as typical for filoviruses and bornaviruses, respectively.

mentioning

confidence: 99%

Tick-Borne Nyamanini Virus Replicates in the Nucleus and Exhibits Unusual Genome and Matrix Protein Properties

Herrel

Hoefs

Staeheli

et al. 2012

“…It has subsequently been isolated in Nigeria, Egypt, India, and Thailand from cattle egrets and Argas walkerae ticks (14,16,24). Although there has been no recognized human infection or disease associated with NYMV, suckling mice succumbed to NYMV infection 7 or 8 days after intracerebral inoculation (14).…”

mentioning

confidence: 99%

Nyamanini and Midway Viruses Define a Novel Taxon of RNA Viruses in the Order Mononegavirales

Mihindukulasuriya

Nguyen

et al. 2009

Here, we report the sequencing and classification of Nyamanini virus (NYMV) and Midway virus (MIDWV), two antigenically related viruses that were first isolated in 1957 and 1966, respectively. Although these viruses have been cultured multiple times from cattle egrets, seabirds, and their ticks, efforts to classify them taxonomically using conventional serological and electron microscopic approaches have failed completely. We used a random shotgun sequencing strategy to define the genomes of NYMV and MIDWV. Contigs of 11,631 and 11,752 nucleotides, representing the complete genome of NYMV and the near-complete genome of MIDWV, respectively, were assembled. Each virus genome was predicted to carry six open reading frames (ORFs). BLAST analysis indicated that only two of the ORF proteins of each virus, the putative nucleocapsid and polymerase, had detectable sequence similarity to known viral proteins. Phylogenetic analysis of these ORF proteins demonstrated that the closest relatives of NYNV and MIDWV are negative-stranded-RNA viruses in the order Mononegavirales. On the basis of their very limited sequence similarity to known viruses, we propose that NYMV and MIDWV define a novel genus, Nyavirus, in this order.Nyamanini virus (NYMV) was first isolated in 1957 from a cattle egret (Bubulcus ibis) in South Africa (24). It has subsequently been isolated in Nigeria, Egypt, India, and Thailand from cattle egrets and Argas walkerae ticks (14,16,24). Although there has been no recognized human infection or disease associated with NYMV, suckling mice succumbed to NYMV infection 7 or 8 days after intracerebral inoculation (14). NYMV has not been definitively characterized or classified to date (10).Midway virus (MIDWV) was first isolated in 1966 from seabird ticks of two species [Ornithodoros (Alectorobius) spp.] collected on the Midway, Kure, and Manana islands in the Central Pacific and from northern Honshu, Japan. In addition, on Aomatsushima Island, nestling seabirds of two seabird species, Larus crassirostris and Nycticorax nycticorax, were found to have antibody to MIDWV. This virus is pathogenic for newborn Swiss mice but not 4-week-old Swiss mice injected intracranially. Also, the virus is cytopathic in BHK-21 cells and produces plaques in Vero cells. Efforts to classify MIDWV have revealed only that MIDWV is antigenically related to NYMV in cross-box complement fixation (CF) assays (22).To date, conventional approaches, such as serological analysis and electron microscopy (EM), have not yielded definitive characterization of MIDWV or NYMV. Heretofore, it was not known whether MIDWV and NYMV are DNA viruses or RNA viruses or to which virus family they belong. In this paper, we describe the application of unbiased high-throughput sequencing to define the genome sequences of NYMV and MIDWV. By analysis of their genomes, NYMV and MIDWV were determined to be negative-stranded RNA viruses highly divergent from all known viruses but most closely related to viruses in the order Mononegavirales. On the basis of the analys...

“…Although these three viruses were only recently recognized as orthomyxoviruses (23), they were originally isolated in the 1950s and 1960s: QRFV in Quaranfil, Egypt, in 1953; JAV in Sand Island, Johnston Atoll, in the North Pacific, in 1964; and LKCV in Lake Chad, Nigeria, in 1969 (24,25). The geographic distribution of QFRV appears to be widespread, stretching across Africa, the Middle East, and Asia (26,27), as does JAV, which in addition to Johnston Atoll has been reportedly isolated in Hawaii (28), Australia (29), and New Zealand (30). In contrast, the natural distribution of LKCV is unknown, as its geographical range can only be inferred from the single isolation of the prototype strain in Nigeria (23).…”

mentioning

confidence: 99%

Cyclic Avian Mass Mortality in the Northeastern United States Is Associated with a Novel Orthomyxovirus

Allison

Ballard

Tesh

et al. 2015

Since 1998, cyclic mortality events in common eiders (Somateria mollissima), numbering in the hundreds to thousands of dead birds, have been documented along the coast of Cape Cod, MA, USA. Although longitudinal disease investigations have uncovered potential contributing factors responsible for these outbreaks, detecting a primary etiological agent has proven enigmatic. Here, we identify a novel orthomyxovirus, tentatively named Wellfleet Bay virus (WFBV), as a potential causative agent of these outbreaks. Genomic analysis of WFBV revealed that it is most closely related to members of the Quaranjavirus genus within the family Orthomyxoviridae. Similar to other members of the genus, WFBV contains an alphabaculovirus gp64-like glycoprotein that was demonstrated to have fusion activity; this also tentatively suggests that ticks (and/or insects) may vector the virus in nature. However, in addition to the six RNA segments encoding the prototypical structural proteins identified in other quaranjaviruses, a previously unknown RNA segment (segment 7) encoding a novel protein designated VP7 was discovered in WFBV. Although WFBV shows low to moderate levels of sequence similarity to Quaranfil virus and Johnston Atoll virus, the original members of the Quaranjavirus genus, additional antigenic and genetic analyses demonstrated that it is closely related to the recently identified Cygnet River virus (CyRV) from South Australia, suggesting that WFBV and CyRV may be geographic variants of the same virus. Although the identification of WFBV in part may resolve the enigma of these mass mortality events, the details of the ecology and epidemiology of the virus remain to be determined. IMPORTANCEThe emergence or reemergence of viral pathogens resulting in large-scale outbreaks of disease in humans and/or animals is one of the most important challenges facing biomedicine. For example, understanding how orthomyxoviruses such as novel influenza A virus reassortants and/or mutants emerge to cause epidemic or pandemic disease is at the forefront of current global health concerns. Here, we describe the emergence of a novel orthomyxovirus, Wellfleet Bay virus (WFBV), which has been associated with cyclic large-scale bird die-offs in the northeastern United States. This initial characterization study provides a foundation for further research into the evolution, epidemiology, and ecology of newly emerging orthomyxoviruses, such as WFBV, and their potential impacts on animal and/or human health.