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Virology Journal Oct 2015In Portugal, entomological surveys to detect phleboviruses in their natural vectors have not been performed so far. Thus, the aims of the present study were to detect,...
BACKGROUND
In Portugal, entomological surveys to detect phleboviruses in their natural vectors have not been performed so far. Thus, the aims of the present study were to detect, isolate and characterize phleboviruses in sandfly populations of Portugal.
FINDINGS
From May to October 2007-2008, 896 female sandflies were trapped in Arrábida region, located on the southwest coast of Portugal. Phlebovirus RNA was detected by using a pan-phlebovirus RT-PCR in 4 out of 34 Phlebotomus perniciosus pools. Direct sequencing of the amplicons showed that 2 samples exhibited 72 % nucleotide identity with Arbia virus, and two showed 96 % nucleotide identity with Massilia virus. The Arbia-like virus (named Alcube virus) was isolated in cell culture and complete genomic sequences of one Alcube and two Massila viruses were determined using next-generation sequencing technology. Phylogenetic analysis demonstrated that Alcube virus clustered with members of the Salehabad virus species complex. Within this clade, Alcube virus forms a monophyletic lineage with the Arbia, Salehabad and Adana viruses sharing a common ancestor. Arbia virus has been identified as the most closely related virus with 20-28 % nucleotide and 10-27 % amino acid divergences depending on the analysed segment.
CONCLUSIONS
We have provided genetic evidence for the circulation of a novel phlebovirus species named Alcube virus in Ph. perniciosus and co-circulation of Massilia virus, in Arrábida region, southwest of Portugal. Further epidemiological investigations and surveillance for sandfly-borne phleboviruses in Portugal are needed to elucidate their medical importance.
Topics: Animals; Cluster Analysis; Female; Genome, Viral; Molecular Sequence Data; Phlebovirus; Phylogeny; Portugal; Psychodidae; RNA, Viral; Sequence Analysis, DNA; Sequence Homology
PubMed: 26497645
DOI: 10.1186/s12985-015-0407-0 -
Current Molecular Medicine Dec 2005Rift Valley fever is considered to be one of the most important viral zoonoses in Africa. In 2000, the Rift valley fever virus spread to the Arabian Peninsula and caused... (Review)
Review
Rift Valley fever is considered to be one of the most important viral zoonoses in Africa. In 2000, the Rift valley fever virus spread to the Arabian Peninsula and caused two simultaneous outbreaks in Yemen and Saudi Arabia. It is transmitted to ruminants and to humans by mosquitoes. The viral agent is an arbovirus, which belongs to the Phlebovirus genus in the Bunyaviridae family. This family of viruses comprises more than 300 members grouped into five genera: Orthobunyavirus, Phlebovirus, Hantavirus, Nairovirus, and Tospovirus. Several members of the Bunyaviridae family are responsible for fatal hemorrhagic fevers: Rift Valley fever virus (Phlebovirus), Crimean-Congo hemorrhagic fever virus (Nairovirus), Hantaan, Sin Nombre and related viruses (Hantavirus), and recently Garissa, now identified as Ngari virus (Orthobunyavirus). Here are reviewed recent advances in Rift Valley fever virus, its epidemiology, molecular biology and focus on recent data on the interactions between viral and cellular proteins, which help to understand the molecular mechanisms utilized by the virus to circumvent the host cellular response.
Topics: Animals; Disease Vectors; Humans; Immunity; Public Health; Rift Valley Fever; Rift Valley fever virus
PubMed: 16375716
DOI: 10.2174/156652405774962263 -
PLoS Pathogens Mar 2023Toscana virus (TOSV) (Bunyavirales, Phenuiviridae, Phlebovirus, Toscana phlebovirus) and other related human pathogenic arboviruses are transmitted by phlebotomine sand...
Toscana virus (TOSV) (Bunyavirales, Phenuiviridae, Phlebovirus, Toscana phlebovirus) and other related human pathogenic arboviruses are transmitted by phlebotomine sand flies. TOSV has been reported in nations bordering the Mediterranean Sea among other regions. Infection can result in febrile illness as well as meningitis and encephalitis. Understanding vector-arbovirus interactions is crucial to improving our knowledge of how arboviruses spread, and in this context, immune responses that control viral replication play a significant role. Extensive research has been conducted on mosquito vector immunity against arboviruses, with RNA interference (RNAi) and specifically the exogenous siRNA (exo-siRNA) pathway playing a critical role. However, the antiviral immunity of phlebotomine sand flies is less well understood. Here we were able to show that the exo-siRNA pathway is active in a Phlebotomus papatasi-derived cell line. Following TOSV infection, distinctive 21 nucleotide virus-derived small interfering RNAs (vsiRNAs) were detected. We also identified the exo-siRNA effector Ago2 in this cell line, and silencing its expression rendered the exo-siRNA pathway largely inactive. Thus, our data show that this pathway is active as an antiviral response against a sand fly transmitted bunyavirus, TOSV.
Topics: Animals; Humans; Sandfly fever Naples virus; Phlebotomus; Psychodidae; RNA Interference; Phlebovirus; Arboviruses; RNA, Small Interfering
PubMed: 36996243
DOI: 10.1371/journal.ppat.1011283 -
Nature Microbiology Mar 2019Severe fever with thrombocytopenia syndrome phlebovirus (SFTSV), listed in the most dangerous pathogens by the World Health Organization, has 12-30% fatality rates with...
Severe fever with thrombocytopenia syndrome phlebovirus (SFTSV), listed in the most dangerous pathogens by the World Health Organization, has 12-30% fatality rates with a characteristic thrombocytopenia syndrome. With a majority of clinically diagnosed SFTSV patients older than ~50 years of age, age is a critical risk factor for SFTSV morbidity and mortality. Here, we report an age-dependent ferret model of SFTSV infection and pathogenesis that fully recapitulates the clinical manifestations of human infections. Whereas young adult ferrets (≤2 years of age) did not show any clinical symptoms and mortality, SFTSV-infected aged ferrets (≥4 years of age) demonstrated severe thrombocytopenia, reduced white blood cell counts and high fever with 93% mortality rate. Moreover, a significantly higher viral load was observed in aged ferrets. Transcriptome analysis of SFTSV-infected young ferrets revealed strong interferon-mediated anti-viral signalling, whereas inflammatory immune responses were markedly upregulated and persisted in aged ferrets. Thus, this immunocompetent age-dependent ferret model should be useful for anti-SFTSV therapy and vaccine development.
Topics: Age Factors; Animals; Bunyaviridae Infections; Disease Models, Animal; Ferrets; Gene Expression Profiling; Humans; Immunocompetence; Inflammation; Interferons; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Phlebovirus; Thrombocytopenia; Viral Load
PubMed: 30531978
DOI: 10.1038/s41564-018-0317-1 -
Virus Research Jul 2023A newly discovered tick-borne virus called the severe fever with thrombocytopenia syndrome virus (SFTSV) can cause the severe fever with thrombocytopenia syndrome...
A newly discovered tick-borne virus called the severe fever with thrombocytopenia syndrome virus (SFTSV) can cause the severe fever with thrombocytopenia syndrome (SFTS). The mortality and incidence rate of SFTS patients remain extremely high due to the fast global dissemination of its arthropod vectors, and the mechanism of viral pathogenesis remains largely unknown. In this study, high-throughput RNA sequencing (RNA-Seq) was used to sequence HEK 293 cells treated with SFTSV at four time points. 115, 191, 259, and 660 differentially expressed genes (DEGs) were identified at 6, 12, 24, and 48 h post-infection, respectively. We found that SFTSV infection induced the expression of genes responsible for numerous cytokine-related pathways, including TNF, CXCL1, CXCL2, CXCL3, CXCL8, CXCL10, and CCL20. With the extension of infection time, the expression of most genes involved in these pathways increased significantly, indicating the host's inflammatory response to SFTSV. Moreover, the expression levels of GNA13, ARHGEF12, RHOA, ROCK1, and MYL12A, elements of the platelet activation signaling pathway, were downregulated during SFTSV infection, suggesting that the SFTSV infection may cause thrombocytopenia by inhibiting platelet activation. Our results contribute to further understanding the interaction between SFTSV and the host.
Topics: Humans; Severe Fever with Thrombocytopenia Syndrome; Bunyaviridae Infections; HEK293 Cells; Phlebovirus; Signal Transduction; rho-Associated Kinases
PubMed: 37211158
DOI: 10.1016/j.virusres.2023.199138 -
Journal of Virology Apr 2013Bhanja 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...
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 and Heartland 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 serogroup viruses 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.
Topics: Amino Acid Motifs; Animals; Base Sequence; Chlorocebus aethiops; DNA Primers; DNA, Complementary; Dogs; Genome, Viral; High-Throughput Nucleotide Sequencing; Likelihood Functions; Macrophages; Microscopy, Electron; Models, Genetic; Molecular Sequence Data; Phlebovirus; Phylogeny; Reverse Transcriptase Polymerase Chain Reaction; Sequence Alignment; Serologic Tests; Species Specificity; Vero Cells
PubMed: 23325688
DOI: 10.1128/JVI.02845-12 -
The Journal of General Virology Aug 2015Punta Toro virus (PTV), a member of the PTV complex, is a relatively common causative agent of febrile illness in Panama that is often misdiagnosed as 'dengue' or...
Punta Toro virus (PTV), a member of the PTV complex, is a relatively common causative agent of febrile illness in Panama that is often misdiagnosed as 'dengue' or 'influenza'. Currently, only two named members make up this species complex, PTV and Buenaventura virus (BUEV). Genomic and antigenic characterization of 17 members of the PTV complex, nine of which were isolated from human acute febrile illness cases, reveals that this species complex is composed of six distant viruses. We propose to add four additional new viruses, designated Leticia virus, Cocle virus, Campana virus and Capira virus.
Topics: Animals; Antibodies, Viral; Bunyaviridae Infections; Cross Reactions; Fever; Humans; Insect Vectors; Molecular Sequence Data; Panama; Phlebovirus; Phylogeny; Psychodidae
PubMed: 25934793
DOI: 10.1099/vir.0.000170 -
Frontiers in Immunology 2024Dabie Banda virus (DBV), a tick-borne pathogen, was first identified in China in 2009 and causes profound symptoms including fever, leukopenia, thrombocytopenia and... (Review)
Review
Dabie Banda virus (DBV), a tick-borne pathogen, was first identified in China in 2009 and causes profound symptoms including fever, leukopenia, thrombocytopenia and multi-organ dysfunction, which is known as severe fever with thrombocytopenia syndrome (SFTS). In the last decade, global incidence and mortality of SFTS increased significantly, especially in East Asia. Though previous studies provide understandings of clinical and immunological characteristics of SFTS development, comprehensive insight of antiviral immunity response is still lacking. Here, we intensively discuss the antiviral immune response after DBV infection by integrating previous ex- and in-vivo studies, including innate and adaptive immune responses, anti-viral immune responses and long-term immune characters. A comprehensive overview of potential immune targets for clinical trials is provided as well. However, development of novel strategies for improving the prognosis of the disease remains on challenge. The current review may shed light on the establishment of immunological interventions for the critical disease SFTS.
Topics: Animals; Humans; Adaptive Immunity; Immunity, Innate; Phlebovirus; Severe Fever with Thrombocytopenia Syndrome
PubMed: 38646523
DOI: 10.3389/fimmu.2024.1348836 -
Viruses Sep 2018First identified in two Missouri farmers exhibiting low white-blood-cell and platelet counts in 2009, Heartland virus (HRTV) is genetically closely related to severe... (Review)
Review
First identified in two Missouri farmers exhibiting low white-blood-cell and platelet counts in 2009, Heartland virus (HRTV) is genetically closely related to severe fever with thrombocytopenia syndrome virus (SFTSV), a tick-borne phlebovirus producing similar symptoms in China, Korea, and Japan. Field isolations of HRTV from several life stages of unfed, host-seeking , the lone star tick, implicated it as a putative vector capable of transstadial transmission. Laboratory vector competence assessments confirmed transstadial transmission of HRTV, demonstrated vertical infection, and showed co-feeding infection between . A vertical infection rate of 33% from adult females to larvae in the laboratory was observed, while only one of 386 pools of molted nymphs (1930) reared from co-feeding larvae was positive for HRTV (maximum-likelihood estimate of infection rate = 0.52/1000). Over 35 human HRTV cases, all within the distribution range of , have been documented. Serological testing of wildlife in areas near the index human cases, as well as in widely separated regions of the eastern United States where occur, indicated many potential hosts such as raccoons and white-tailed deer. Attempts, however, to experimentally infect mice, rabbits, hamsters, chickens, raccoons, goats, and deer failed to produce detectable viremia. Immune-compromised mice and hamsters are the only susceptible models. Vertical infection augmented by co-feeding transmission could play a role in maintaining the virus in nature. A more complete assessment of the natural transmission cycle of HRTV coupled with serosurveys and enhanced HRTV disease surveillance are needed to better understand transmission dynamics and human health risks.
Topics: Animals; Bunyaviridae Infections; Disease Management; Disease Models, Animal; Disease Vectors; Host-Pathogen Interactions; Humans; Phlebovirus; Phylogeny; Population Surveillance; United States
PubMed: 30223439
DOI: 10.3390/v10090498 -
The American Journal of Tropical... Apr 2014Thirty pools from 900 (540 females and 360 males) Phlebotomus perfiliewi sandflies collected during the summer of 2012 in the Fermo area (Marche Region, central Italy)...
Thirty pools from 900 (540 females and 360 males) Phlebotomus perfiliewi sandflies collected during the summer of 2012 in the Fermo area (Marche Region, central Italy) were tested for the presence of Phleboviruses. A nested polymerase chain reaction was performed using degenerated primers amplifying a fragment of the polymerase gene (large segment) and a fragment of the nucleoprotein gene (small segment) of the genus Phlebovirus. One pool was positive for Toscana virus, as expected from results of studies in the area, and six pools were positive for a putative novel Phlebovirus. Virus isolation in Vero cells was performed. Minimum field infection rates/1,000 insects processed for the novel and Toscana viruses were 6.7 and 1.0, respectively. Phylogenetic analysis of the novel Phlebovirus, tentatively named Fermo virus, placed it in the Sandfly Fever Naples virus serocomplex.
Topics: Animals; Female; Insect Vectors; Italy; Male; Phlebotomus; Phlebovirus; RNA, Viral; Sandfly fever Naples virus
PubMed: 24534812
DOI: 10.4269/ajtmh.13-0457