Selected Scientific Abstracts
J Virol. 2013 Mar;87(6):3187-95. doi: 10.1128/JVI.02719-12. Epub 2013 Jan 2.
Characterization of the Uukuniemi virus group (Phlebovirus: Bunyaviridae): evidence for seven distinct species.
Evolutionary insights into the phleboviruses are limited because of an imprecise classification scheme based on partial nucleotide sequences and scattered antigenic relationships. In this report, the serologic and phylogenetic relationships of the Uukuniemi group viruses and their relationships with other recently characterized tick-borne phleboviruses are described using full-length genome sequences. We propose that the viruses currently included in the Uukuniemi virus group be assigned to five different species as follows:
Uukuniemi virus, EgAn 1825-61virus, Fin V707 virus, Chizé virus, and Zaliv Terpenia virus would be classified into the Uukuniemi species; Murrevirus, RML-105-105355 virus, and Sunday Canyon virus would be classified into a Murre virus species; and Grand Arbaud virus, Precarious Point virus, and Manawa virus would each be given individual species status.
Although limited sequence similarity was detected between current members of the Uukuniemi group and Severe fever with thrombocytopenia syndrome virus (SFTSV) and Heartland virus, a clear serological reaction was observed between some of them, indicating that SFTSV and Heartland virus should be considered part of the Uukuniemi virus group.
Moreover, based on the genomic diversity of the phleboviruses and given the low correlation observed between complement fixation titers and genetic distance, we propose a system for classification of the Bunyaviridae based on genetic as well as serological data. Finally, the recent descriptions of SFTSV and Heartland virus also indicate that the public health importance of the Uukuniemi group viruses must be reevaluated.
J Virol. 2013 Apr;87(7):3719-28. doi: 10.1128/JVI.02845-12. Epub 2013 Jan 16.
Characterization of the Bhanja serogroup viruses (Bunyaviridae): a novel species of the genus Phlebovirus and its relationship with other emerging tick-borne phleboviruses.
Bhanja virus (BHAV) and its antigenically close relatives Forecariah virus (FORV), Kismayo virus (KISV), and Palma virus (PALV) are thought to be members of the family Bunyaviridae, but they have not been assigned to a genus or species. Despite their broad geographical distribution and reports that BHAV causes sporadic cases of febrile illness and encephalitis in humans, the public health importance of the Bhanja serogroup viruses remains unclear, due in part to the lack of sequence and biochemical information for the virus proteins.
In order to better define the molecular characteristics of this group, we determined the full-length sequences of the L, M, and S genome segments of multiple isolates of BHAV as well as FORV and PALV. The genome structures of these Bhanja viruses are similar to those of viruses belonging to the genus Phlebovirus. Functional domains and amino acid motifs in the viral proteins that are conserved among other known phleboviruses were also identified in proteins of the BHAV group.
Phylogenetic and serological analyses revealed that the BHAVs are most closely related to the novel emerging tick-borne phleboviruses severe fever with thrombocytopenia syndrome virus andHeartland virus, which have recently been implicated as causing severe acute febrile illnesses associated with thrombocytopenia in humans in China and the United States.
Our results indicate that the Bhanja serogroupviruses constitute a single novel species in the genus Phlebovirus. The results of this study should facilitate epidemiological surveillance for other, similar tick-borne phleboviruses that may represent unrecognized causes of febrile illness in humans.
PLoS One. 2013 Apr 29;8(4):e62083. doi: 10.1371/journal.pone.0062083. Print 2013.
The genome sequence of Lone Star virus, a highly divergent bunyavirus found in the Amblyomma americanum tick.
Viruses in the family Bunyaviridae infect a wide range of plant, insect, and animal hosts. Tick-borne bunyaviruses in the Phlebovirus genus, including Severe Fever with Thrombocytopenia Syndrome virus (SFTSV) in China,Heartland virus (HRTV) in the United States, and Bhanja virus in Eurasia and Africa have been associated with acute febrile illness in humans.
Here we sought to characterize the growth characteristics and genome of Lone Star virus (LSV), an unclassified bunyavirus originally isolated from the lone star tick Amblyomma americanum. LSV was able to infect both human (HeLa) and monkey (Vero) cells. Cytopathic effects were seen within 72 h in both cell lines; vacuolization was observed in infected Vero, but not HeLa, cells.
Viral culture supernatants were examined by unbiased deep sequencing and analysis using an in-house developed rapid computational pipeline for viral discovery, which definitively identified LSV as a phlebovirus. De novo assembly of the full genome revealed that LSV is highly divergent, sharing <61% overall amino acid identity with any other bunyavirus.
Despite this sequence diversity, LSV was found by phylogenetic analysis to be part of a well-supported clade that includes members of the Bhanja group viruses, which are most closely related to SFSTV/HRTV.
The genome sequencing of LSV is a critical first step in developing diagnostic tools to determine the risk of arbovirus transmission by A. americanum, a tick of growing importance given its expanding geographic range and competence as a disease vector. This study also underscores the power of deep sequencing analysis in rapidly identifying and sequencing the genomes of viruses of potential clinical and public health significance.
Emerg Infect Dis. 2013 Jun;19(6):864-9. doi: 10.3201/eid1906.130173.
Cell culture and electron microscopy for identifying viruses in diseases of unknown cause.
Goldsmith CS, Ksiazek TG, Rollin PE, Comer JA, Nicholson WL, Peret TC, Erdman DD, Bellini WJ, Harcourt BH, Rota PA, Bhatnagar J, Bowen MD, Erickson BR, McMullan LK, Nichol ST, Shieh WJ, Paddock CD, Zaki SR.
During outbreaks of infectious diseases or in cases of severely ill patients, it is imperative to identify the causative agent. This report describes several events in which virus isolation and identification by electron microscopy were critical to initial recognition of the etiologic agent, which was further analyzed by additional laboratory diagnostic assays.
Examples include severe acute respiratory syndrome coronavirus, and Nipah, lymphocytic choriomeningitis, West Nile, Cache Valley, and Heartland viruses. These cases illustrate the importance of the techniques of cell culture and electron microscopy in pathogen identification and recognition of emerging diseases.
Free full text http://wwwnc.cdc.gov/eid/article/19/6/13-0173_article.htm
OTHER ARTICLES & NEWS
Tick-Borne Virus May Have Claimed Third Victim in Korea
A 69-year-old man who died this week in the southern port city of Busan may have been the third victim to fall prey to a tick-borne virus in the country in recent weeks, although the cause of death is still being investigated.
Pusan National University Yangsan Hospital, the medical center to which the man was admitted, said he suffered from a high fever and indigestion before he died of septicemia.
The hospital has reported the case to the Korea Centers for Disease Control and Prevention, saying the patient might have been infected with the tick-borne virus known as SFTS, or severe fever with thrombocytopenia syndrome.
Two people have died from the virus in Korea over the past month or so.
Arirang News / May 27, 2013 10:53 KST