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Sample records for giant viruses infecting

  1. Fatal canine distemper virus infection of giant pandas in China.

    PubMed

    Feng, Na; Yu, Yicong; Wang, Tiecheng; Wilker, Peter; Wang, Jianzhong; Li, Yuanguo; Sun, Zhe; Gao, Yuwei; Xia, Xianzhu

    2016-01-01

    We report an outbreak of canine distemper virus (CDV) infection among endangered giant pandas (Ailuropoda melanoleuca). Five of six CDV infected giant pandas died. The surviving giant panda was previously vaccinated against CDV. Genomic sequencing of CDV isolated from one of the infected pandas (giant panda/SX/2014) suggests it belongs to the Asia-1 cluster. The hemagglutinin protein of the isolated virus and virus sequenced from lung samples originating from deceased giant pandas all possessed the substitutions V26M, T213A, K281R, S300N, P340Q, and Y549H. The presence of the Y549H substitution is notable as it is found at the signaling lymphocytic activation molecule (SLAM) receptor-binding site and has been implicated in the emergence of highly pathogenic CDV and host switching. These findings demonstrate that giant pandas are susceptible to CDV and suggest that surveillance and vaccination among all captive giant pandas are warranted to support conservation efforts for this endangered species. PMID:27310722

  2. Fatal canine distemper virus infection of giant pandas in China

    PubMed Central

    Feng, Na; Yu, Yicong; Wang, Tiecheng; Wilker, Peter; Wang, Jianzhong; Li, Yuanguo; Sun, Zhe; Gao, Yuwei; Xia, Xianzhu

    2016-01-01

    We report an outbreak of canine distemper virus (CDV) infection among endangered giant pandas (Ailuropoda melanoleuca). Five of six CDV infected giant pandas died. The surviving giant panda was previously vaccinated against CDV. Genomic sequencing of CDV isolated from one of the infected pandas (giant panda/SX/2014) suggests it belongs to the Asia-1 cluster. The hemagglutinin protein of the isolated virus and virus sequenced from lung samples originating from deceased giant pandas all possessed the substitutions V26M, T213A, K281R, S300N, P340Q, and Y549H. The presence of the Y549H substitution is notable as it is found at the signaling lymphocytic activation molecule (SLAM) receptor-binding site and has been implicated in the emergence of highly pathogenic CDV and host switching. These findings demonstrate that giant pandas are susceptible to CDV and suggest that surveillance and vaccination among all captive giant pandas are warranted to support conservation efforts for this endangered species. PMID:27310722

  3. Influenza A(H1N1)pdm09 virus infection in giant pandas, China.

    PubMed

    Li, Desheng; Zhu, Ling; Cui, Hengmin; Ling, Shanshan; Fan, Shengtao; Yu, Zhijun; Zhou, Yuancheng; Wang, Tiecheng; Qian, Jun; Xia, Xianzhu; Xu, Zhiwen; Gao, Yuwei; Wang, Chengdong

    2014-03-01

    We confirmed infection with influenza A(H1N1)pdm09 in giant pandas in China during 2009 by using virus isolation and serologic analysis methods. This finding extends the host range of influenza viruses and indicates a need for increased surveillance for and control of influenza viruses among giant pandas. PMID:24565026

  4. "Marseilleviridae", a new family of giant viruses infecting amoebae.

    PubMed

    Colson, Philippe; Pagnier, Isabelle; Yoosuf, Niyaz; Fournous, Ghislain; La Scola, Bernard; Raoult, Didier

    2013-04-01

    The family "Marseilleviridae" is a new proposed taxon for giant viruses that infect amoebae. Its first member, Acanthamoeba polyphaga marseillevirus (APMaV), was isolated in 2007 by culturing on amoebae a water sample collected from a cooling tower in Paris, France. APMaV has an icosahedral shape with a diameter of ≈250 nm. Its genome is a double-stranded circular DNA that is 368,454 base pairs (bp) in length. The genome has a GC content of 44.7 % and is predicted to encode 457 proteins. Phylogenetic reconstructions showed that APMaV belongs to a new viral family among nucleocytoplasmic large DNA viruses, a group of viruses that also includes Acanthamoeba polyphaga mimivirus (APMV) and the other members of the family Mimiviridae as well as the members of the families Poxviridae, Phycodnaviridae, Iridoviridae, Ascoviridae, and Asfarviridae. In 2011, Acanthamoeba castellanii lausannevirus (ACLaV), another close relative of APMaV, was isolated from river water in France. The ACLaV genome is 346,754 bp in size and encodes 450 genes, among which 320 have an APMaV protein as the closest homolog. Two other giant viruses closely related to APMaV and ACLaV have been recovered in our laboratory from a freshwater sample and a human stool sample using an amoebal co-culture method. The only currently identified hosts for "marseilleviruses" are Acanthamoeba spp. The prevalence of these viruses in the environment and in animals and humans remains to be determined. PMID:23188494

  5. Epidermal multinucleated giant cells are not always a histopathologic clue to a herpes virus infection: multinucleated epithelial giant cells in the epidermis of lesional skin biopsies from patients with acantholytic dermatoses can histologically mimic a herpes virus infection

    PubMed Central

    Cohen, Philip R.; Paravar, Taraneh; Lee, Robert A.

    2014-01-01

    Background: Multinucleated giant cells in the epidermis can either be epithelial or histiocytic. Epithelial multinucleated giant cells are most often associated with herpes virus infections. Purpose: To review the histologic differential diagnosis of conditions with epithelial and histiocytic multinucleated giant cells—since multinucleated giant cells in the epidermis are not always pathognomonic of a cutaneous herpes virus infection—and to summarize dermatoses in which herpes virus infection has been observed to coexist. Methods: Two individuals with acantholytic dermatoses whose initial lesional skin biopsies showed multinucleated epithelial giant cells suggestive of a herpes virus infection are reported. Using the PubMed database, an extensive literature search was performed on multinucleated giant cell (and epidermis, epithelial, and histiocytic) and herpes virus infection. Relevant papers were reviewed to discover the skin conditions with either multinucleated giant cells in the epidermis or coincident cutaneous herpes virus infection. Results: Initial skin biopsies from patients with either pemphigus vulgaris or transient acantholytic dermatosis mimicked herpes virus infection; however, laboratory studies and repeat biopsies established the correct diagnosis of their acantholytic dermatosis. Hence, epidermal multinucleated giant cells are not always a histopathologic clue to a herpes virus infection. Indeed, epithelial multinucleated giant cells in the epidermis can be observed not only in the presence of infection (herpes virus), but also acantholytic dermatoses and tumors (trichoepithelioma and pleomorphic basal cell carcinoma). Histiocytic multinucleated giant cells in the epidermis can be observed in patients with either giant cell lichenoid dermatitis or lichen nitidus of the palms. Conclusions: Epithelial and histiocytic multinucleated giant cell can occur in the epidermis. Keratinocyte-derived multinucleated giant cells are most commonly associated

  6. Characterisation of three novel giant viruses reveals huge diversity among viruses infecting Prymnesiales (Haptophyta).

    PubMed

    Johannessen, Torill Vik; Bratbak, Gunnar; Larsen, Aud; Ogata, Hiroyuki; Egge, Elianne S; Edvardsen, Bente; Eikrem, Wenche; Sandaa, Ruth-Anne

    2015-02-01

    We have isolated three novel lytic dsDNA-viruses from Raunefjorden (Norway) that are putative members of the Mimiviridae family, namely Haptolina ericina virus RF02 (HeV RF02), Prymnesium kappa virus RF01 (PkV RF01), and Prymnesium kappa virus RF02 (PkV RF02). Each of the novel haptophyte viruses challenges the common conceptions of algal viruses with respect to host range, phylogenetic affiliation and size. PkV RF01 has a capsid of ~310 nm and is the largest algal virus particle ever reported while PkV RF01 and HeV RF02 were able to infect different species, even belonging to different genera. Moreover, PkV RF01 and HeV RF02 infected the same hosts, but phylogenetic analysis placed them in different groups. Our results reveal large variation among viruses infecting closely related microalgae, and challenge the common conception that algal viruses have narrow host range, and phylogeny reflecting their host affiliation. PMID:25546253

  7. Giant virus with a remarkable complement of genes infects marine zooplankton

    PubMed Central

    Fischer, Matthias G.; Allen, Michael J.; Wilson, William H.; Suttle, Curtis A.

    2010-01-01

    As major consumers of heterotrophic bacteria and phytoplankton, microzooplankton are a critical link in aquatic foodwebs. Here, we show that a major marine microflagellate grazer is infected by a giant virus, Cafeteria roenbergensis virus (CroV), which has the largest genome of any described marine virus (≈730 kb of double-stranded DNA). The central 618-kb coding part of this AT-rich genome contains 544 predicted protein-coding genes; putative early and late promoter motifs have been detected and assigned to 191 and 72 of them, respectively, and at least 274 genes were expressed during infection. The diverse coding potential of CroV includes predicted translation factors, DNA repair enzymes such as DNA mismatch repair protein MutS and two photolyases, multiple ubiquitin pathway components, four intein elements, and 22 tRNAs. Many genes including isoleucyl-tRNA synthetase, eIF-2γ, and an Elp3-like histone acetyltransferase are usually not found in viruses. We also discovered a 38-kb genomic region of putative bacterial origin, which encodes several predicted carbohydrate metabolizing enzymes, including an entire pathway for the biosynthesis of 3-deoxy-d-manno-octulosonate, a key component of the outer membrane in Gram-negative bacteria. Phylogenetic analysis indicates that CroV is a nucleocytoplasmic large DNA virus, with Acanthamoeba polyphaga mimivirus as its closest relative, although less than one-third of the genes of CroV have homologs in Mimivirus. CroV is a highly complex marine virus and the only virus studied in genetic detail that infects one of the major groups of predators in the oceans. PMID:20974979

  8. Giant virus with a remarkable complement of genes infects marine zooplankton.

    PubMed

    Fischer, Matthias G; Allen, Michael J; Wilson, William H; Suttle, Curtis A

    2010-11-01

    As major consumers of heterotrophic bacteria and phytoplankton, microzooplankton are a critical link in aquatic foodwebs. Here, we show that a major marine microflagellate grazer is infected by a giant virus, Cafeteria roenbergensis virus (CroV), which has the largest genome of any described marine virus (≈730 kb of double-stranded DNA). The central 618-kb coding part of this AT-rich genome contains 544 predicted protein-coding genes; putative early and late promoter motifs have been detected and assigned to 191 and 72 of them, respectively, and at least 274 genes were expressed during infection. The diverse coding potential of CroV includes predicted translation factors, DNA repair enzymes such as DNA mismatch repair protein MutS and two photolyases, multiple ubiquitin pathway components, four intein elements, and 22 tRNAs. Many genes including isoleucyl-tRNA synthetase, eIF-2γ, and an Elp3-like histone acetyltransferase are usually not found in viruses. We also discovered a 38-kb genomic region of putative bacterial origin, which encodes several predicted carbohydrate metabolizing enzymes, including an entire pathway for the biosynthesis of 3-deoxy-d-manno-octulosonate, a key component of the outer membrane in Gram-negative bacteria. Phylogenetic analysis indicates that CroV is a nucleocytoplasmic large DNA virus, with Acanthamoeba polyphaga mimivirus as its closest relative, although less than one-third of the genes of CroV have homologs in Mimivirus. CroV is a highly complex marine virus and the only virus studied in genetic detail that infects one of the major groups of predators in the oceans. PMID:20974979

  9. Proteorhodopsin genes in giant viruses

    PubMed Central

    2012-01-01

    Viruses with large genomes encode numerous proteins that do not directly participate in virus biogenesis but rather modify key functional systems of infected cells. We report that a distinct group of giant viruses infecting unicellular eukaryotes that includes Organic Lake Phycodnaviruses and Phaeocystis globosa virus encode predicted proteorhodopsins that have not been previously detected in viruses. Search of metagenomic sequence data shows that putative viral proteorhodopsins are extremely abundant in marine environments. Phylogenetic analysis suggests that giant viruses acquired proteorhodopsins via horizontal gene transfer from proteorhodopsin-encoding protists although the actual donor(s) could not be presently identified. The pattern of conservation of the predicted functionally important amino acid residues suggests that viral proteorhodopsin homologs function as sensory rhodopsins. We hypothesize that viral rhodopsins modulate light-dependent signaling, in particular phototaxis, in infected protists. This article was reviewed by Igor B. Zhulin and Laksminarayan M. Iyer. For the full reviews, see the Reviewers’ reports section. PMID:23036091

  10. Plant genomes enclose footprints of past infections by giant virus relatives

    PubMed Central

    Maumus, Florian; Epert, Aline; Nogué, Fabien; Blanc, Guillaume

    2014-01-01

    Nucleocytoplasmic large DNA viruses (NCLDVs) are eukaryotic viruses with large genomes (100 kb–2.5 Mb), which include giant Mimivirus, Megavirus and Pandoravirus. NCLDVs are known to infect animals, protists and phytoplankton but were never described as pathogens of land plants. Here, we show that the bryophyte Physcomitrella patens and the lycophyte Selaginella moellendorffii have open reading frames (ORFs) with high phylogenetic affinities to NCLDV homologues. The P. patens genes are clustered in DNA stretches (up to 13 kb) containing up to 16 NCLDV-like ORFs. Molecular evolution analysis suggests that the NCLDV-like regions were acquired by horizontal gene transfer from distinct but closely related viruses that possibly define a new family of NCLDVs. Transcriptomics and DNA methylation data indicate that the NCLDV-like regions are transcriptionally inactive and are highly cytosine methylated through a mechanism not relying on small RNAs. Altogether, our data show that members of NCLDV have infected land plants. PMID:24969138

  11. Giant viruses come of age.

    PubMed

    Fischer, Matthias G

    2016-06-01

    Viruses with genomes up to a few megabases in length are a common occurrence in nature, even though they have escaped our notice until recently. These giant viruses infect mainly single-celled eukaryotes and isolation efforts concentrating on amoebal hosts alone have spawned hundreds of viral isolates, featuring viruses with previously unseen virion morphologies and the largest known viral genomes and particles. One of the challenges that lie ahead is to analyze and categorize the available data and to establish an approved classification system that reflects the evolutionary relationships and biological properties of these viruses. Extensive sampling of Acanthamoeba-infecting mimiviruses and initial characterization of their virophage parasites have provided a first blueprint of the genetic diversity and composition of a giant virus clade that will facilitate the taxonomic grouping of these fascinating microorganisms. PMID:26999382

  12. In-depth study of Mollivirus sibericum, a new 30,000-y-old giant virus infecting Acanthamoeba.

    PubMed

    Legendre, Matthieu; Lartigue, Audrey; Bertaux, Lionel; Jeudy, Sandra; Bartoli, Julia; Lescot, Magali; Alempic, Jean-Marie; Ramus, Claire; Bruley, Christophe; Labadie, Karine; Shmakova, Lyubov; Rivkina, Elizaveta; Couté, Yohann; Abergel, Chantal; Claverie, Jean-Michel

    2015-09-22

    Acanthamoeba species are infected by the largest known DNA viruses. These include icosahedral Mimiviruses, amphora-shaped Pandoraviruses, and Pithovirus sibericum, the latter one isolated from 30,000-y-old permafrost. Mollivirus sibericum, a fourth type of giant virus, was isolated from the same permafrost sample. Its approximately spherical virion (0.6-µm diameter) encloses a 651-kb GC-rich genome encoding 523 proteins of which 64% are ORFans; 16% have their closest homolog in Pandoraviruses and 10% in Acanthamoeba castellanii probably through horizontal gene transfer. The Mollivirus nucleocytoplasmic replication cycle was analyzed using a combination of "omic" approaches that revealed how the virus highjacks its host machinery to actively replicate. Surprisingly, the host's ribosomal proteins are packaged in the virion. Metagenomic analysis of the permafrost sample uncovered the presence of both viruses, yet in very low amount. The fact that two different viruses retain their infectivity in prehistorical permafrost layers should be of concern in a context of global warming. Giant viruses' diversity remains to be fully explored. PMID:26351664

  13. In-depth study of Mollivirus sibericum, a new 30,000-y-old giant virus infecting Acanthamoeba

    PubMed Central

    Legendre, Matthieu; Lartigue, Audrey; Bertaux, Lionel; Jeudy, Sandra; Bartoli, Julia; Lescot, Magali; Alempic, Jean-Marie; Ramus, Claire; Bruley, Christophe; Labadie, Karine; Shmakova, Lyubov; Rivkina, Elizaveta; Couté, Yohann; Abergel, Chantal; Claverie, Jean-Michel

    2015-01-01

    Acanthamoeba species are infected by the largest known DNA viruses. These include icosahedral Mimiviruses, amphora-shaped Pandoraviruses, and Pithovirus sibericum, the latter one isolated from 30,000-y-old permafrost. Mollivirus sibericum, a fourth type of giant virus, was isolated from the same permafrost sample. Its approximately spherical virion (0.6-µm diameter) encloses a 651-kb GC-rich genome encoding 523 proteins of which 64% are ORFans; 16% have their closest homolog in Pandoraviruses and 10% in Acanthamoeba castellanii probably through horizontal gene transfer. The Mollivirus nucleocytoplasmic replication cycle was analyzed using a combination of “omic” approaches that revealed how the virus highjacks its host machinery to actively replicate. Surprisingly, the host’s ribosomal proteins are packaged in the virion. Metagenomic analysis of the permafrost sample uncovered the presence of both viruses, yet in very low amount. The fact that two different viruses retain their infectivity in prehistorical permafrost layers should be of concern in a context of global warming. Giant viruses’ diversity remains to be fully explored. PMID:26351664

  14. Evolutionary dynamics of giant viruses and their virophages.

    PubMed

    Wodarz, Dominik

    2013-07-01

    Giant viruses contain large genomes, encode many proteins atypical for viruses, replicate in large viral factories, and tend to infect protists. The giant virus replication factories can in turn be infected by so called virophages, which are smaller viruses that negatively impact giant virus replication. An example is Mimiviruses that infect the protist Acanthamoeba and that are themselves infected by the virophage Sputnik. This study examines the evolutionary dynamics of this system, using mathematical models. While the models suggest that the virophage population will evolve to increasing degrees of giant virus inhibition, it further suggests that this renders the virophage population prone to extinction due to dynamic instabilities over wide parameter ranges. Implications and conditions required to avoid extinction are discussed. Another interesting result is that virophage presence can fundamentally alter the evolutionary course of the giant virus. While the giant virus is predicted to evolve toward increasing its basic reproductive ratio in the absence of the virophage, the opposite is true in its presence. Therefore, virophages can not only benefit the host population directly by inhibiting the giant viruses but also indirectly by causing giant viruses to evolve toward weaker phenotypes. Experimental tests for this model are suggested. PMID:23919155

  15. Synthesis of giant globular multivalent glycofullerenes as potent inhibitors in a model of Ebola virus infection

    NASA Astrophysics Data System (ADS)

    Muñoz, Antonio; Sigwalt, David; Illescas, Beatriz M.; Luczkowiak, Joanna; Rodríguez-Pérez, Laura; Nierengarten, Iwona; Holler, Michel; Remy, Jean-Serge; Buffet, Kevin; Vincent, Stéphane P.; Rojo, Javier; Delgado, Rafael; Nierengarten, Jean-François; Martín, Nazario

    2016-01-01

    The use of multivalent carbohydrate compounds to block cell-surface lectin receptors is a promising strategy to inhibit the entry of pathogens into cells and could lead to the discovery of novel antiviral agents. One of the main problems with this approach, however, is that it is difficult to make compounds of an adequate size and multivalency to mimic natural systems such as viruses. Hexakis adducts of [60]fullerene are useful building blocks in this regard because they maintain a globular shape at the same time as allowing control over the size and multivalency. Here we report water-soluble tridecafullerenes decorated with 120 peripheral carbohydrate subunits, so-called ‘superballs’, that can be synthesized efficiently from hexakis adducts of [60]fullerene in one step by using copper-catalysed azide-alkyne cycloaddition click chemistry. Infection assays show that these superballs are potent inhibitors of cell infection by an artificial Ebola virus with half-maximum inhibitory concentrations in the subnanomolar range.

  16. Provirophages and transpovirons as the diverse mobilome of giant viruses.

    PubMed

    Desnues, Christelle; La Scola, Bernard; Yutin, Natalya; Fournous, Ghislain; Robert, Catherine; Azza, Saïd; Jardot, Priscilla; Monteil, Sonia; Campocasso, Angélique; Koonin, Eugene V; Raoult, Didier

    2012-10-30

    A distinct class of infectious agents, the virophages that infect giant viruses of the Mimiviridae family, has been recently described. Here we report the simultaneous discovery of a giant virus of Acanthamoeba polyphaga (Lentille virus) that contains an integrated genome of a virophage (Sputnik 2), and a member of a previously unknown class of mobile genetic elements, the transpovirons. The transpovirons are linear DNA elements of ~7 kb that encompass six to eight protein-coding genes, two of which are homologous to virophage genes. Fluorescence in situ hybridization showed that the free form of the transpoviron replicates within the giant virus factory and accumulates in high copy numbers inside giant virus particles, Sputnik 2 particles, and amoeba cytoplasm. Analysis of deep-sequencing data showed that the virophage and the transpoviron can integrate in nearly any place in the chromosome of the giant virus host and that, although less frequently, the transpoviron can also be linked to the virophage chromosome. In addition, integrated fragments of transpoviron DNA were detected in several giant virus and Sputnik genomes. Analysis of 19 Mimivirus strains revealed three distinct transpovirons associated with three subgroups of Mimiviruses. The virophage, the transpoviron, and the previously identified self-splicing introns and inteins constitute the complex, interconnected mobilome of the giant viruses and are likely to substantially contribute to interviral gene transfer. PMID:23071316

  17. Origin of giant viruses from smaller DNA viruses not from a fourth domain of cellular life

    PubMed Central

    Yutin, Natalya; Wolf, Yuri I.; Koonin, Eugene V.

    2015-01-01

    The numerous and diverse eukaryotic viruses with large double-stranded DNA genomes that at least partially reproduce in the cytoplasm of infected cells apparently evolved from a single virus ancestor. This major group of viruses is known as Nucleocytoplasmic Large DNA Viruses (NCLDV) or the proposed order Megavirales. Among the “Megavirales”, there are three groups of giant viruses with genomes exceeding 500 kb, namely Mimiviruses, Pithoviruses, and Pandoraviruses that hold the current record of viral genome size, about 2.5 Mb. Phylogenetic analysis of conserved, ancestral NLCDV genes clearly shows that these three groups of giant viruses have three distinct origins within the “Megavirales”. The Mimiviruses constitute a distinct family that is distantly related to Phycodnaviridae, Pandoraviruses originate from a common ancestor with Coccolithoviruses within the Phycodnaviridae family, and Pithoviruses are related to Iridoviridae and Marseilleviridae. Maximum likelihood reconstruction of gene gain and loss events during the evolution of the “Megavirales” indicates that each group of giant viruses evolved from viruses with substantially smaller and simpler gene repertoires. Initial phylogenetic analysis of universal genes, such as translation system components, encoded by some giant viruses, in particular Mimiviruses, has led to the hypothesis that giant viruses descend from a fourth, probably extinct domain of cellular life. The results of our comprehensive phylogenomic analysis of giant viruses refute the fourth domain hypothesis and instead indicate that the universal genes have been independently acquired by different giant viruses from their eukaryotic hosts. PMID:25042053

  18. Giant viruses of amoebae as potential human pathogens.

    PubMed

    Colson, Philippe; La Scola, Bernard; Raoult, Didier

    2013-01-01

    Giant viruses infecting phagocytic protists are composed of mimiviruses, the record holders of particle and genome size amongst viruses, and marseilleviruses. Since the discovery in 2003 at our laboratory of the first of these giant viruses, the Mimivirus, a growing body of data has revealed that they are common inhabitants of our biosphere. Moreover, from the outset, the story of Mimivirus has been linked to that of patients exhibiting pneumonia and it was shown that patients developed antibodies to this amoebal pathogen. Since then, there have been several proven cases of human infection or colonization with giant viruses of amoebae, which are known to host several bacteria that are human pathogens. Mimiviruses and marseilleviruses represent a major challenge in human pathology, as virological procedures implemented to date have not used appropriate media to allow their culture, and molecular techniques have used filtration steps that likely prevented their detection. Nevertheless, there is an increasing body of evidence that mimiviruses might cause pneumonia and that humans carry marseilleviruses, and re-analyses of metagenomic databases have provided evidence that these giant viruses can be common in human samples. The proportion of human infections related to these giant mimiviruses and marseilleviruses and the precise short- and long-term consequences of these infections have been scarcely investigated so far and should be the subject of future works. PMID:24157884

  19. Giants among larges: how gigantism impacts giant virus entry into amoebae.

    PubMed

    Rodrigues, Rodrigo Araújo Lima; Abrahão, Jônatas Santos; Drumond, Betânia Paiva; Kroon, Erna Geessien

    2016-06-01

    The proposed order Megavirales comprises the nucleocytoplasmic large DNA viruses (NCLDV), infecting a wide range of hosts. Over time, they co-evolved with different host cells, developing various strategies to penetrate them. Mimiviruses and other giant viruses enter cells through phagocytosis, while Marseillevirus and other large viruses explore endocytosis and macropinocytosis. These differing strategies might reflect the evolution of those viruses. Various scenarios have been proposed for the origin and evolution of these viruses, presenting one of the most enigmatic issues to surround these microorganisms. In this context, we believe that giant viruses evolved independently by massive gene/size gain, exploring the phagocytic pathway of entry into amoebas. In response to gigantism, hosts developed mechanisms to evade these parasites. PMID:27039270

  20. Giant Viruses of Amoebas: An Update.

    PubMed

    Aherfi, Sarah; Colson, Philippe; La Scola, Bernard; Raoult, Didier

    2016-01-01

    During the 12 past years, five new or putative virus families encompassing several members, namely Mimiviridae, Marseilleviridae, pandoraviruses, faustoviruses, and virophages were described. In addition, Pithovirus sibericum and Mollivirus sibericum represent type strains of putative new giant virus families. All these viruses were isolated using amoebal coculture methods. These giant viruses were linked by phylogenomic analyses to other large DNA viruses. They were then proposed to be classified in a new viral order, the Megavirales, on the basis of their common origin, as shown by a set of ancestral genes encoding key viral functions, a common virion architecture, and shared major biological features including replication inside cytoplasmic factories. Megavirales is increasingly demonstrated to stand in the tree of life aside Bacteria, Archaea, and Eukarya, and the megavirus ancestor is suspected to be as ancient as cellular ancestors. In addition, giant amoebal viruses are visible under a light microscope and display many phenotypic and genomic features not found in other viruses, while they share other characteristics with parasitic microbes. Moreover, these organisms appear to be common inhabitants of our biosphere, and mimiviruses and marseilleviruses were isolated from human samples and associated to diseases. In the present review, we describe the main features and recent findings on these giant amoebal viruses and virophages. PMID:27047465

  1. Giant Viruses of Amoebas: An Update

    PubMed Central

    Aherfi, Sarah; Colson, Philippe; La Scola, Bernard; Raoult, Didier

    2016-01-01

    During the 12 past years, five new or putative virus families encompassing several members, namely Mimiviridae, Marseilleviridae, pandoraviruses, faustoviruses, and virophages were described. In addition, Pithovirus sibericum and Mollivirus sibericum represent type strains of putative new giant virus families. All these viruses were isolated using amoebal coculture methods. These giant viruses were linked by phylogenomic analyses to other large DNA viruses. They were then proposed to be classified in a new viral order, the Megavirales, on the basis of their common origin, as shown by a set of ancestral genes encoding key viral functions, a common virion architecture, and shared major biological features including replication inside cytoplasmic factories. Megavirales is increasingly demonstrated to stand in the tree of life aside Bacteria, Archaea, and Eukarya, and the megavirus ancestor is suspected to be as ancient as cellular ancestors. In addition, giant amoebal viruses are visible under a light microscope and display many phenotypic and genomic features not found in other viruses, while they share other characteristics with parasitic microbes. Moreover, these organisms appear to be common inhabitants of our biosphere, and mimiviruses and marseilleviruses were isolated from human samples and associated to diseases. In the present review, we describe the main features and recent findings on these giant amoebal viruses and virophages. PMID:27047465

  2. Viruses Infecting Reptiles

    PubMed Central

    Marschang, Rachel E.

    2011-01-01

    A large number of viruses have been described in many different reptiles. These viruses include arboviruses that primarily infect mammals or birds as well as viruses that are specific for reptiles. Interest in arboviruses infecting reptiles has mainly focused on the role reptiles may play in the epidemiology of these viruses, especially over winter. Interest in reptile specific viruses has concentrated on both their importance for reptile medicine as well as virus taxonomy and evolution. The impact of many viral infections on reptile health is not known. Koch’s postulates have only been fulfilled for a limited number of reptilian viruses. As diagnostic testing becomes more sensitive, multiple infections with various viruses and other infectious agents are also being detected. In most cases the interactions between these different agents are not known. This review provides an update on viruses described in reptiles, the animal species in which they have been detected, and what is known about their taxonomic positions. PMID:22163336

  3. The origins of giant viruses, virophages and their relatives in host genomes

    PubMed Central

    2014-01-01

    Giant viruses have revealed a number of surprises that challenge conventions on what constitutes a virus. The Samba virus newly isolated in Brazil expands the known distribution of giant mimiviruses to a near-global scale. These viruses, together with the transposon-related virophages that infect them, pose a number of questions about their evolutionary origins that need to be considered in the light of the complex entanglement between host, virus and virophage genomes. See research article: http://www.virologyj.com/content/11/1/95. PMID:25184667

  4. Giant viruses of the Kutch Desert.

    PubMed

    Kerepesi, Csaba; Grolmusz, Vince

    2016-03-01

    The Kutch Desert (Great Rann of Kutch, Gujarat, India) is a unique ecosystem: in the larger part of the year it is a hot, salty desert that is flooded regularly in the Indian monsoon season. In the dry season, the crystallized salt deposits form the "white desert" in large regions. The first metagenomic analysis of the soil samples of Kutch was published in 2013, and the data were deposited in the NCBI Sequence Read Archive. At the same time, the sequences were analyzed phylogenetically for prokaryotes, especially for bacteria. In the present work, we identified DNA sequences of recently discovered giant viruses in the soil samples from the Kutch Desert. Since most giant viruses have been discovered in biofilms in industrial cooling towers, ocean water, and freshwater ponds, we were surprised to find their DNA sequences in soil samples from a seasonally very hot and arid, salty environment. PMID:26666442

  5. [ZIKA--VIRUS INFECTION].

    PubMed

    Velev, V

    2016-01-01

    This review summarizes the knowledge of the scientific community for Zika-virus infection. It became popular because of severe congenital damage causes of CNS in newborns whose mothers are infected during pregnancy, as well as the risk of pandemic distribution. Discusses the peculiarities of the biology and ecology of vectors--blood-sucking mosquitoes Aedes; stages in the spread of infection and practical problems which caused during pregnancy. Attention is paid to the recommendations that allow leading national and international medical organizations to deal with the threat Zika-virus infection. PMID:27509655

  6. Reclassification of giant viruses composing a fourth domain of life in the new order Megavirales.

    PubMed

    Colson, Philippe; de Lamballerie, Xavier; Fournous, Ghislain; Raoult, Didier

    2012-01-01

    Interest in giant viruses has risen sharply since 2003, following the discovery of the Mimivirus and four other protist-infecting giant viruses that are linked to the nucleocytoplasmic large DNA viruses (NCLDVs). Despite considerable heterogeneity in hosts and genome sizes, the NCLDVs have been shown to be monophyletic based on analyses of their sequences and gene repertoires and recent studies have proposed that these viruses share a common ancient ancestor and compose a fourth domain of life. In addition, several characteristics of these giant viruses contradict or do not match the criteria used for the canonical definition of viruses, and the NCLDV denomination is not completely appropriate. We propose here to define a new viral order named Megavirales. PMID:22508375

  7. The role of giant viruses of amoebas in humans.

    PubMed

    Colson, Philippe; Aherfi, Sarah; La Scola, Bernard; Raoult, Didier

    2016-06-01

    Since 2003, dozens of giant viruses that infect amoebas (GVA), including mimiviruses and marseilleviruses, have been discovered. These giants appear to be common in our biosphere. From the onset, their presence and possible pathogenic role in humans have been serendipitously observed or investigated using a broad range of technological approaches, including culture, electron microscopy, serology and various techniques based on molecular biology. The link between amoebal mimiviruses and pneumonia has been the most documented, with findings that fulfill several of the criteria considered as proof of viral disease causation. Regarding marseilleviruses, they have been mostly described in asymptomatic persons, and in a lymph node adenitis. The presence and impact of GVA in humans undoubtedly deserve further investigation in medicine. PMID:27131020

  8. Human Influenza Virus Infections.

    PubMed

    Peteranderl, Christin; Herold, Susanne; Schmoldt, Carole

    2016-08-01

    Seasonal and pandemic influenza are the two faces of respiratory infections caused by influenza viruses in humans. As seasonal influenza occurs on an annual basis, the circulating virus strains are closely monitored and a yearly updated vaccination is provided, especially to identified risk populations. Nonetheless, influenza virus infection may result in pneumonia and acute respiratory failure, frequently complicated by bacterial coinfection. Pandemics are, in contrary, unexpected rare events related to the emergence of a reassorted human-pathogenic influenza A virus (IAV) strains that often causes increased morbidity and spreads extremely rapidly in the immunologically naive human population, with huge clinical and economic impact. Accordingly, particular efforts are made to advance our knowledge on the disease biology and pathology and recent studies have brought new insights into IAV adaptation mechanisms to the human host, as well as into the key players in disease pathogenesis on the host side. Current antiviral strategies are only efficient at the early stages of the disease and are challenged by the genomic instability of the virus, highlighting the need for novel antiviral therapies targeting the pulmonary host response to improve viral clearance, reduce the risk of bacterial coinfection, and prevent or attenuate acute lung injury. This review article summarizes our current knowledge on the molecular basis of influenza infection and disease progression, the key players in pathogenesis driving severe disease and progression to lung failure, as well as available and envisioned prevention and treatment strategies against influenza virus infection. PMID:27486731

  9. Schmallenberg virus infection.

    PubMed

    Wernike, K; Elbers, A; Beer, M

    2015-08-01

    Since Schmallenberg virus, an orthobunyavirus of the Simbu serogroup, was identified near the German-Dutch border for the first time in late 2011 it has spread extremely quickly and caused a large epidemic in European livestock. The virus, which is transmitted by Culicoides biting midges, infects domestic and wild ruminants. Adult animals show only mild clinical symptoms or none at all, whereas an infection during a critical period of gestation can lead to abortion, stillbirth or the birth of severely malformed offspring. The impact of the disease is usually greater in sheep than in cattle. Vaccination could be an important aspect of disease control. PMID:26601441

  10. Yellow Fever Virus Infection

    PubMed Central

    David-West, Tam. S.; Smith, J. A.

    1971-01-01

    A sequential and quantitative survey of brain and liver of suckling mice for infective virus and complement-fixing antigen, after infection with yellow fever virus, showed that while there was progressive increase of infective virus content in both organs, only the brain showed a corresponding rise in CF antigen. Histopathological examination revealed that the liver was not significantly involved. The target organ was the brain, where the progressive pathological changes culminated in an acute encephalitis by the 3rd day of experiment. Organ destruction began with the molecular layer of the grey matter. But by the 4th day after infection the entire cerebral cortex was involved. At the initial stages the hippocampus was particularly affected. Tissue damage did not appear to be entirely due to the differential quantitative localization of infective virus. It was hypothesized that the CF antigen acting singly or in conjunction with some hypothetical proteins may be principally involved in the pathological outcome of the disease. ImagesFigs. 7-9Figs. 3-6 PMID:5582071

  11. Feline immunodeficiency virus infection.

    PubMed

    Pedersen, N C; Yamamoto, J K; Ishida, T; Hansen, H

    1989-05-01

    Feline immunodeficiency virus (FIV) (formerly feline T-lymphotropic lentivirus or FTLV) was first isolated from a group of cats in Petaluma, California in 1986. The virus is a typical lentivirus in gross and structural morphology. It replicates preferentially but not exclusively in feline T-lymphoblastoid cells, where it causes a characteristic cytopathic effect. The major structural proteins are 10, 17 (small gag), 28 (major core), 31 (endonuclease?), 41 (transmembrane?), 52 (core precursor polyprotein), 54/62 (reverse transcriptase?), and 110/130 (major envelope) kilodaltons in size. The various proteins are antigenically distinguishable from those of other lentiviruses, although serum from EIAV-infected horses will cross-react with some FIV antigens. Kittens experimentally infected with FIV manifest a transient (several days to 2 weeks) fever and neutropenia beginning 4 to 8 weeks after inoculation. This is associated with a generalized lymphadenopathy that persists for up to 9 months. Most cats recover from this initial phase of the disease and become lifelong carriers of the virus. Complete recovery does not occur to any extent in nature or in the laboratory setting. One experimentally infected cat died from a myeloproliferative disorder several months after infection. The terminal AIDS-like phase of the illness has been seen mainly in naturally infected cats. It appears a year or more following the initial infection in an unknown proportion of infected animals. FIV has been identified in cats from all parts of the world. It is most prevalent in high density populations of free roaming cats (feral and pet), and is very uncommon in closed purebred catteries. Male cats are twice as likely to become infected as females. Older male cats adopted as feral or stray animals are at the highest risk of infection, therefore. The infection rate among freely roaming cats rises throughout life, and reaches levels ranging from less than 1% to 12% or more depending on the

  12. Varicella zoster virus infection.

    PubMed

    Gershon, Anne A; Breuer, Judith; Cohen, Jeffrey I; Cohrs, Randall J; Gershon, Michael D; Gilden, Don; Grose, Charles; Hambleton, Sophie; Kennedy, Peter G E; Oxman, Michael N; Seward, Jane F; Yamanishi, Koichi

    2015-01-01

    Infection with varicella zoster virus (VZV) causes varicella (chickenpox), which can be severe in immunocompromised individuals, infants and adults. Primary infection is followed by latency in ganglionic neurons. During this period, no virus particles are produced and no obvious neuronal damage occurs. Reactivation of the virus leads to virus replication, which causes zoster (shingles) in tissues innervated by the involved neurons, inflammation and cell death - a process that can lead to persistent radicular pain (postherpetic neuralgia). The pathogenesis of postherpetic neuralgia is unknown and it is difficult to treat. Furthermore, other zoster complications can develop, including myelitis, cranial nerve palsies, meningitis, stroke (vasculopathy), retinitis, and gastroenterological infections such as ulcers, pancreatitis and hepatitis. VZV is the only human herpesvirus for which highly effective vaccines are available. After varicella or vaccination, both wild-type and vaccine-type VZV establish latency, and long-term immunity to varicella develops. However, immunity does not protect against reactivation. Thus, two vaccines are used: one to prevent varicella and one to prevent zoster. In this Primer we discuss the pathogenesis, diagnosis, treatment, and prevention of VZV infections, with an emphasis on the molecular events that regulate these diseases. For an illustrated summary of this Primer, visit: http://go.nature.com/14xVI1. PMID:27188665

  13. [Zika virus infection during pregnancy].

    PubMed

    Picone, O; Vauloup-Fellous, C; D'Ortenzio, E; Huissoud, C; Carles, G; Benachi, A; Faye, A; Luton, D; Paty, M-C; Ayoubi, J-M; Yazdanpanah, Y; Mandelbrot, L; Matheron, S

    2016-05-01

    A Zika virus epidemic is currently ongoing in the Americas. This virus is linked to congenital infections with potential severe neurodevelopmental dysfunction. However, incidence of fetal infection and whether this virus is responsible of other fetal complications are still unknown. National and international public health authorities recommend caution and several prevention measures. Declaration of Zika virus infection is now mandatory in France. Given the available knowledge on Zika virus, we suggest here a review of the current recommendations for management of pregnancy in case of suspicious or infection by Zika virus in a pregnant woman. PMID:27079865

  14. Hepatitis E Virus Infection

    PubMed Central

    Dalton, Harry R.; Abravanel, Florence; Izopet, Jacques

    2014-01-01

    SUMMARY Hepatitis E virus (HEV) infection is a worldwide disease. An improved understanding of the natural history of HEV infection has been achieved within the last decade. Several reservoirs and transmission modes have been identified. Hepatitis E is an underdiagnosed disease, in part due to the use of serological assays with low sensitivity. However, diagnostic tools, including nucleic acid-based tests, have been improved. The epidemiology and clinical features of hepatitis E differ between developing and developed countries. HEV infection is usually an acute self-limiting disease, but in developed countries it causes chronic infection with rapidly progressive cirrhosis in organ transplant recipients, patients with hematological malignancy requiring chemotherapy, and individuals with HIV. HEV also causes extrahepatic manifestations, including a number of neurological syndromes and renal injury. Acute infection usually requires no treatment, but chronic infection should be treated by reducing immunosuppression in transplant patients and/or the use of antiviral therapy. In this comprehensive review, we summarize the current knowledge about the virus itself, as well as the epidemiology, diagnostics, natural history, and management of HEV infection in developing and developed countries. PMID:24396139

  15. Proteomic analysis of differentially expressed protein in hemocytes of wild giant freshwater prawn Macrobrachium rosenbergii infected with infectious hypodermal and hematopoietic necrosis virus (IHHNV)

    PubMed Central

    Alinejad, T.; Bin, Kwong Q.; Vejayan, J.; Othman, R.Y.; Bhassu, S.

    2015-01-01

    Epizootic diseases cause huge mortality and economical loses at post larvae stages in freshwater prawn aquaculture industry. These prawns seem less susceptible to viral diseases except for infectious hypodermal and hematopoietic necrosis virus (IHHNV). During viral infection in prawns, hemocytes are the primary organ that shows immunological response within the early stages of infection. We applied proteomic approaches to understand differential expression of the proteins in hemocytes during the viral disease outbreak. To aid the goal, we collected Macrobrachium rosenbergii broodstocks from the local grow out hatchery which reported the first incidence of IHHNV viral outbreak during larvae stage. Primarily, application of the OIE primer targeting 389 bp fragments of IHHNV virus was used in identification of the infected and non-infected samples of the prawn breeding line. Analysis of two-dimensional gel electrophoresis showed specific down-regulation of Arginine kinase and Sarcoplasmic calcium-binding protein and up/down-regulation of Prophenoloxidase1 and hemocyanin isoforms. These proteins were validated using semi quantitative RT-PCR and gene transcripts at mRNA level. These identified proteins can be used as biomarkers, providing a powerful approach to better understanding of the immunity pathway of viral disease with applications in analytic and observational epidemiology diagnosis. Proteomic profiling allows deep insight into the pathogenesis of IHHNV molecular regulation and mechanism of hemocyte in freshwater prawns. PMID:26106581

  16. Proteomic analysis of differentially expressed protein in hemocytes of wild giant freshwater prawn Macrobrachium rosenbergii infected with infectious hypodermal and hematopoietic necrosis virus (IHHNV).

    PubMed

    Alinejad, T; Bin, Kwong Q; Vejayan, J; Othman, R Y; Bhassu, S

    2015-09-01

    Epizootic diseases cause huge mortality and economical loses at post larvae stages in freshwater prawn aquaculture industry. These prawns seem less susceptible to viral diseases except for infectious hypodermal and hematopoietic necrosis virus (IHHNV). During viral infection in prawns, hemocytes are the primary organ that shows immunological response within the early stages of infection. We applied proteomic approaches to understand differential expression of the proteins in hemocytes during the viral disease outbreak. To aid the goal, we collected Macrobrachium rosenbergii broodstocks from the local grow out hatchery which reported the first incidence of IHHNV viral outbreak during larvae stage. Primarily, application of the OIE primer targeting 389 bp fragments of IHHNV virus was used in identification of the infected and non-infected samples of the prawn breeding line. Analysis of two-dimensional gel electrophoresis showed specific down-regulation of Arginine kinase and Sarcoplasmic calcium-binding protein and up/down-regulation of Prophenoloxidase1 and hemocyanin isoforms. These proteins were validated using semi quantitative RT-PCR and gene transcripts at mRNA level. These identified proteins can be used as biomarkers, providing a powerful approach to better understanding of the immunity pathway of viral disease with applications in analytic and observational epidemiology diagnosis. Proteomic profiling allows deep insight into the pathogenesis of IHHNV molecular regulation and mechanism of hemocyte in freshwater prawns. PMID:26106581

  17. Parainfluenza Virus Infection.

    PubMed

    Branche, Angela R; Falsey, Ann R

    2016-08-01

    Human parainfluenza viruses (HPIVs) are single-stranded, enveloped RNA viruses of the Paramyoviridaie family. There are four serotypes which cause respiratory illnesses in children and adults. HPIVs bind and replicate in the ciliated epithelial cells of the upper and lower respiratory tract and the extent of the infection correlates with the location involved. Seasonal HPIV epidemics result in a significant burden of disease in children and account for 40% of pediatric hospitalizations for lower respiratory tract illnesses (LRTIs) and 75% of croup cases. Parainfluenza viruses are associated with a wide spectrum of illnesses which include otitis media, pharyngitis, conjunctivitis, croup, tracheobronchitis, and pneumonia. Uncommon respiratory manifestations include apnea, bradycardia, parotitis, and respiratory distress syndrome and rarely disseminated infection. Immunity resulting from disease in childhood is incomplete and reinfection with HPIV accounts for 15% of respiratory illnesses in adults. Severe disease and fatal pneumonia may occur in elderly and immunocompromised adults. HPIV pneumonia in recipients of hematopoietic stem cell transplant (HSCT) is associated with 50% acute mortality and 75% mortality at 6 months. Though sensitive molecular diagnostics are available to rapidly diagnose HPIV infection, effective antiviral therapies are not available. Currently, treatment for HPIV infection is supportive with the exception of croup where the use of corticosteroids has been found to be beneficial. Several novel drugs including DAS181 appear promising in efforts to treat severe disease in immunocompromised patients, and vaccines to decrease the burden of disease in young children are in development. PMID:27486735

  18. West Nile Virus Infection.

    PubMed

    Sejvar, James J

    2016-06-01

    Although long recognized as a human pathogen, West Nile virus (WNV) emerged as a significant public health problem following its introduction and spread across North America. Subsequent years have seen a greater understanding of all aspects of this viral infection. The North American epidemic resulted in a further understanding of the virology, pathogenesis, clinical features, and epidemiology of WNV infection. Approximately 80% of human WNV infections are asymptomatic. Most symptomatic people experience an acute systemic febrile illness; less than 1% of infected people develop neuroinvasive disease, which typically manifests as meningitis, encephalitis, or anterior myelitis resulting in acute flaccid paralysis. Older age is associated with more severe illness and higher mortality; other risk factors for poor outcome have been challenging to identify. In addition to natural infection through mosquito bites, transfusion- and organ transplant-associated infections have occurred. Since there is no definitive treatment for WNV infection, protection from mosquito bites and other preventative measures are critical. WNV has reached an endemic pattern in North America, but the future epidemiologic pattern is uncertain. PMID:27337465

  19. Zika virus infections.

    PubMed

    de Laval, F; Leparc-Goffart, I; Meynard, J-B; Daubigny, H; Simon, F; Briolant, S

    2016-05-01

    Since its discovery in 1947 in Uganda, the Zika virus (ZIKV) remained in the shadows emerging in 2007 in Micronesia, where hundreds of dengue-like syndromes were reported. Then, in 2013-2014, it was rife in French Polynesia, where the first neurological effects were observed. More recently, its arrival in Brazil was accompanied by an unusually high number of children with microcephaly born to mothers infected with ZIKV during the first trimester of pregnancy. In 2016, the World Health Organization declared ZIKV infection to be a public health emergency and now talks about a ZIKV pandemic. This review aims to summarize the current knowledge about ZIKV infection, successively addressing its transmission, epidemiology, clinical aspects, diagnosis, treatment, and prevention before discussing some perspectives. PMID:27412976

  20. Recognition of Linear B-Cell Epitope of Betanodavirus Coat Protein by RG-M18 Neutralizing mAB Inhibits Giant Grouper Nervous Necrosis Virus (GGNNV) Infection

    PubMed Central

    Chen, Chien-Wen; Wu, Ming-Shan; Huang, Yi-Jen; Cheng, Chao-An; Chang, Chi-Yao

    2015-01-01

    Betanodavirus is a causative agent of viral nervous necrosis syndrome in many important aquaculture marine fish larvae, resulting in high global mortality. The coat protein of Betanodavirus is the sole structural protein, and it can assemble the virion particle by itself. In this study, we used a high-titer neutralizing mAB, RG-M18, to identify the linear B-cell epitope on the viral coat protein. By mapping a series of recombinant proteins generated using the E. coli PET expression system, we demonstrated that the linear epitope recognized by RG-M18 is located at the C-terminus of the coat protein, between amino acid residues 195 and 338. To define the minimal epitope region, a set of overlapping peptides were synthesized and evaluated for RG-M18 binding. Such analysis identified the 195VNVSVLCR202 motif as the minimal epitope. Comparative analysis of Alanine scanning mutagenesis with dot-blotting and ELISA revealed that Valine197, Valine199, and Cysteine201 are critical for antibody binding. Substitution of Leucine200 in the RGNNV, BFNNV, and TPNNV genotypes with Methionine200 (thereby simulating the SJNNV genotype) did not affect binding affinity, implying that RG-M18 can recognize all genotypes of Betanodaviruses. In competition experiments, synthetic multiple antigen peptides of this epitope dramatically suppressed giant grouper nervous necrosis virus (GGNNV) propagation in grouper brain cells. The data provide new insights into the protective mechanism of this neutralizing mAB, with broader implications for Betanodavirus vaccinology and antiviral peptide drug development. PMID:25938761

  1. Updating strategies for isolating and discovering giant viruses.

    PubMed

    Khalil, Jacques Yaacoub Bou; Andreani, Julien; La Scola, Bernard

    2016-06-01

    Almost fifteen years ago, the discovery of Acanthamoeba polyphaga mimivirus, the first giant virus, changed how we define a virus. It was discovered incidentally in a process of isolating Legionella sp. from environmental samples in the context of pneumonia epidemics using a co-culture system with Acanthamoeba. Since then, much effort and improvement has been put into the original technique. In addition to the known families of Mimiviridae and Marseilleviridae, four new proposed families of giant viruses have been isolated: Pandoravirus, Pithovirus, Faustovirus and Mollivirus. Major improvements were based on enrichment systems, targeted use of antibiotics and high-throughput methods. The most recent development, using flow cytometry for isolation and presumptive identification systems, opens a path to large environmental surveys that may discover new giant virus families in new protozoa supports used for culture support. PMID:27039269

  2. Zika Virus Infection and Microcephaly.

    PubMed

    Millichap, J Gordon

    2016-01-01

    A Task Force established by the Brazil Ministry of Health investigated the possible association of microcephaly with Zika virus infection during pregnancy and a registry for microcephaly cases among women suspected to have had Zika virus infection during pregnancy. PMID:27004142

  3. Structures of giant icosahedral eukaryotic dsDNA viruses

    PubMed Central

    Xiao, Chuan; Rossmann, Michael G.

    2011-01-01

    In the last twenty years, numerous giant, dsDNA, icosahedral viruses have been discovered and assigned to the nucleocytoplasmic large dsDNA virus (NCLDV) clade. The major capsid proteins of these viruses consist of two consecutive jelly-roll domains, assembled into trimers, with pseudo 6-fold symmetry. The capsomers are assembled into arrays that have either p6 (as in Paramecium bursaria Chlorella virus-1) or p3 symmetry (as in Mimivirus). Most of the NCLDV viruses have a membrane that separates the nucleocapsid from the external capsid. PMID:21909343

  4. Human Immunodeficiency Virus (HIV) Primary Infection

    MedlinePlus

    ... rashes clinical tools newsletter | contact Share | Human Immunodeficiency Virus (HIV) Primary Infection Information for adults A A ... weeks following exposure to HIV (the human immunodeficiency virus). Chronic infection with this virus can cause AIDS ( ...

  5. Respiratory Syncytial Virus Infections

    MedlinePlus

    Respiratory syncytial virus (RSV) causes mild, cold-like symptoms in adults and older healthy children. It can cause serious problems in ... tests can tell if your child has the virus. There is no specific treatment. You should give ...

  6. Samba virus: a novel mimivirus from a giant rain forest, the Brazilian Amazon

    PubMed Central

    2014-01-01

    Background The identification of novel giant viruses from the nucleocytoplasmic large DNA viruses group and their virophages has increased in the last decade and has helped to shed light on viral evolution. This study describe the discovery, isolation and characterization of Samba virus (SMBV), a novel giant virus belonging to the Mimivirus genus, which was isolated from the Negro River in the Brazilian Amazon. We also report the isolation of an SMBV-associated virophage named Rio Negro (RNV), which is the first Mimivirus virophage to be isolated in the Americas. Methods/results Based on a phylogenetic analysis, SMBV belongs to group A of the putative Megavirales order, possibly a new virus related to Acanthamoeba polyphaga mimivirus (APMV). SMBV is the largest virus isolated in Brazil, with an average particle diameter about 574 nm. The SMBV genome contains 938 ORFs, of which nine are ORFans. The 1,213.6 kb SMBV genome is one of the largest genome of any group A Mimivirus described to date. Electron microscopy showed RNV particle accumulation near SMBV and APMV factories resulting in the production of defective SMBV and APMV particles and decreasing the infectivity of these two viruses by several logs. Conclusion This discovery expands our knowledge of Mimiviridae evolution and ecology. PMID:24886672

  7. Human Papilloma Virus Infections

    PubMed Central

    Wright, V. Cecil

    1989-01-01

    Genital warts are believed to be caused by human papilloma viruses and to be sexually transmitted. The viruses are classified by DNA types, which appear to cause different types of disease. The choice of treatment, and usually its success rate, vary according to the type of disease and its location. PMID:21248973

  8. Isolation of new Brazilian giant viruses from environmental samples using a panel of protozoa

    PubMed Central

    Dornas, Fábio P.; Khalil, Jacques Y. B.; Pagnier, Isabelle; Raoult, Didier; Abrahão, Jônatas; La Scola, Bernard

    2015-01-01

    The Megavirales are a newly described order capable of infecting different types of eukaryotic hosts. For the most part, the natural host is unknown. Several methods have been used to detect these viruses, with large discrepancies between molecular methods and co-cultures. To isolate giant viruses, we propose the use of different species of amoeba as a cellular support. The aim of this work was to isolate new Brazilian giant viruses by comparing the protozoa Acanthamoeba castellanii, A. polyphaga, A. griffini, and Vermamoeba vermiformis (VV) as a platform for cellular isolation using environmental samples. One hundred samples were collected from 3 different areas in September 2014 in the Pampulha lagoon of Belo Horizonte city, Minas Gerais, Brazil. PCR was used to identify the isolated viruses, along with hemacolor staining, labelling fluorescence and electron microscopy. A total of 69 viruses were isolated. The highest ratio of isolation was found in A. polyphaga (46.38%) and the lowest in VV (0%). Mimiviruses were the most frequently isolated. One Marseillevirus and one Pandoravirus were also isolated. With Brazilian environmental samples, we demonstrated the high rate of lineage A mimiviruses. This work demonstrates how these viruses survive and circulate in nature as well the differences between protozoa as a platform for cellular isolation. PMID:26500630

  9. Transcriptomic analysis of the host response to an iridovirus infection in Chinese giant salamander, Andrias davidianus.

    PubMed

    Fan, Yuding; Chang, Ming Xian; Ma, Jie; LaPatra, Scott E; Hu, Yi Wei; Huang, Lili; Nie, Pin; Zeng, Lingbing

    2015-01-01

    The emergence of an infectious viral disease caused by the Chinese giant salamander iridovirus (GSIV) has led to substantial economic losses. However, no more molecular information is available for the understanding of the mechanisms associated with virus-host interaction. In this study, de novo sequencing was used to obtain abundant high-quality ESTs and investigate differentially-expressed genes in the spleen of Chinese giant salamanders that were either infected or mock infected with GSIV. Comparative expression analysis indicated that 293 genes were down-regulated and 220 genes were up-regulated. Further enrichment analysis showed that the most enriched pathway is "complement and coagulation cascades", and significantly enriched diseases include "inherited thrombophilia", "immune system diseases", "primary immunodeficiency", "complement regulatory protein defects", and "disorders of nucleotide excision repair". Additionally, 30 678 simple sequence repeats (SSRs) from all spleen samples, 26 355 single nucleotide polymorphisms (SNPs) from the spleens of uninfected animals and 36 070 SNPs from the spleens of infected animals were detected. The large amount of variation was specific for the Chinese giant salamanders that were infected with GSIV. The results reported herein provided significant and new EST information that could contribute greatly in investigations into the molecular functions of immune genes in the Chinese giant salamander. PMID:26589400

  10. Provirophages in the Bigelowiella genome bear testimony to past encounters with giant viruses

    PubMed Central

    Blanc, Guillaume; Gallot-Lavallée, Lucie; Maumus, Florian

    2015-01-01

    Virophages are recently discovered double-stranded DNA virus satellites that prey on giant viruses (nucleocytoplasmic large DNA viruses; NCLDVs), which are themselves parasites of unicellular eukaryotes. This coupled parasitism can result in the indirect control of eukaryotic cell mortality by virophages. However, the details of such tripartite relationships remain largely unexplored. We have discovered ∼300 predicted genes of putative virophage origin in the nuclear genome of the unicellular alga Bigelowiella natans. Physical clustering of these genes indicates that virophage genomes are integrated into the B. natans genome. Virophage inserts show high levels of similarity and synteny between each other, indicating that they are closely related. Virophage genes are transcribed not only in the sequenced B. natans strain but also in other Bigelowiella isolates, suggesting that transcriptionally active virophage inserts are widespread in Bigelowiella populations. Evidence that B. natans is also a host to NCLDV members is provided by the identification of NCLDV inserts in its genome. These putative large DNA viruses may be infected by B. natans virophages. We also identify four repeated elements sharing structural and genetic similarities with transpovirons—a class of mobile elements first discovered in giant viruses—that were probably independently inserted in the B. natans genome. We argue that endogenized provirophages may be beneficial to both the virophage and B. natans by (i) increasing the chances for the virophage to coinfect the host cell with an NCLDV prey and (ii) defending the host cell against fatal NCLDV infections. PMID:26305943

  11. Fatal Toxoplasma gondii infection in the giant panda

    PubMed Central

    Ma, Hongyu; Wang, Zedong; Wang, Chengdong; Li, Caiwu; Wei, Feng; Liu, Quan

    2015-01-01

    Toxoplasma gondii can infect nearly all warm-blooded animals. We report an acute fatal T. gondii infection in the endangered giant panda (Ailuropoda melanoleuca) in a zoo in China, characterized by acute gastroenteritis and respiratory symptoms. T. gondii infection was confirmed by immunological and molecular methods. Multilocus nested PCR-RFLP revealed clonal type I at the SAG1 and c29-2 loci, clonal type II at the SAG2, BTUB, GRA6, c22-8, and L358 loci, and clonal type III at the alternative SAG2 and SAG3 loci, thus, a potential new genotype of T. gondii in the giant panda. Other possible pathogens were not detected. To our knowledge, this is the first report of clinical toxoplasmosis in a giant panda. PMID:26514595

  12. Fatal Toxoplasma gondii infection in the giant panda.

    PubMed

    Ma, Hongyu; Wang, Zedong; Wang, Chengdong; Li, Caiwu; Wei, Feng; Liu, Quan

    2015-01-01

    Toxoplasma gondii can infect nearly all warm-blooded animals. We report an acute fatal T. gondii infection in the endangered giant panda (Ailuropoda melanoleuca) in a zoo in China, characterized by acute gastroenteritis and respiratory symptoms. T. gondii infection was confirmed by immunological and molecular methods. Multilocus nested PCR-RFLP revealed clonal type I at the SAG1 and c29-2 loci, clonal type II at the SAG2, BTUB, GRA6, c22-8, and L358 loci, and clonal type III at the alternative SAG2 and SAG3 loci, thus, a potential new genotype of T. gondii in the giant panda. Other possible pathogens were not detected. To our knowledge, this is the first report of clinical toxoplasmosis in a giant panda. PMID:26514595

  13. Thirty-thousand-year-old distant relative of giant icosahedral DNA viruses with a pandoravirus morphology.

    PubMed

    Legendre, Matthieu; Bartoli, Julia; Shmakova, Lyubov; Jeudy, Sandra; Labadie, Karine; Adrait, Annie; Lescot, Magali; Poirot, Olivier; Bertaux, Lionel; Bruley, Christophe; Couté, Yohann; Rivkina, Elizaveta; Abergel, Chantal; Claverie, Jean-Michel

    2014-03-18

    The largest known DNA viruses infect Acanthamoeba and belong to two markedly different families. The Megaviridae exhibit pseudo-icosahedral virions up to 0.7 μm in diameter and adenine-thymine (AT)-rich genomes of up to 1.25 Mb encoding a thousand proteins. Like their Mimivirus prototype discovered 10 y ago, they entirely replicate within cytoplasmic virion factories. In contrast, the recently discovered Pandoraviruses exhibit larger amphora-shaped virions 1 μm in length and guanine-cytosine-rich genomes up to 2.8 Mb long encoding up to 2,500 proteins. Their replication involves the host nucleus. Whereas the Megaviridae share some general features with the previously described icosahedral large DNA viruses, the Pandoraviruses appear unrelated to them. Here we report the discovery of a third type of giant virus combining an even larger pandoravirus-like particle 1.5 μm in length with a surprisingly smaller 600 kb AT-rich genome, a gene content more similar to Iridoviruses and Marseillevirus, and a fully cytoplasmic replication reminiscent of the Megaviridae. This suggests that pandoravirus-like particles may be associated with a variety of virus families more diverse than previously envisioned. This giant virus, named Pithovirus sibericum, was isolated from a >30,000-y-old radiocarbon-dated sample when we initiated a survey of the virome of Siberian permafrost. The revival of such an ancestral amoeba-infecting virus used as a safe indicator of the possible presence of pathogenic DNA viruses, suggests that the thawing of permafrost either from global warming or industrial exploitation of circumpolar regions might not be exempt from future threats to human or animal health. PMID:24591590

  14. Thirty-thousand-year-old distant relative of giant icosahedral DNA viruses with a pandoravirus morphology

    PubMed Central

    Legendre, Matthieu; Bartoli, Julia; Shmakova, Lyubov; Jeudy, Sandra; Labadie, Karine; Adrait, Annie; Lescot, Magali; Poirot, Olivier; Bertaux, Lionel; Bruley, Christophe; Couté, Yohann; Rivkina, Elizaveta; Abergel, Chantal; Claverie, Jean-Michel

    2014-01-01

    The largest known DNA viruses infect Acanthamoeba and belong to two markedly different families. The Megaviridae exhibit pseudo-icosahedral virions up to 0.7 μm in diameter and adenine–thymine (AT)-rich genomes of up to 1.25 Mb encoding a thousand proteins. Like their Mimivirus prototype discovered 10 y ago, they entirely replicate within cytoplasmic virion factories. In contrast, the recently discovered Pandoraviruses exhibit larger amphora-shaped virions 1 μm in length and guanine–cytosine-rich genomes up to 2.8 Mb long encoding up to 2,500 proteins. Their replication involves the host nucleus. Whereas the Megaviridae share some general features with the previously described icosahedral large DNA viruses, the Pandoraviruses appear unrelated to them. Here we report the discovery of a third type of giant virus combining an even larger pandoravirus-like particle 1.5 μm in length with a surprisingly smaller 600 kb AT-rich genome, a gene content more similar to Iridoviruses and Marseillevirus, and a fully cytoplasmic replication reminiscent of the Megaviridae. This suggests that pandoravirus-like particles may be associated with a variety of virus families more diverse than previously envisioned. This giant virus, named Pithovirus sibericum, was isolated from a >30,000-y-old radiocarbon-dated sample when we initiated a survey of the virome of Siberian permafrost. The revival of such an ancestral amoeba-infecting virus used as a safe indicator of the possible presence of pathogenic DNA viruses, suggests that the thawing of permafrost either from global warming or industrial exploitation of circumpolar regions might not be exempt from future threats to human or animal health. PMID:24591590

  15. Respiratory Syncytial Virus Infections

    MedlinePlus

    ... countertops. Washing your hands often and not sharing eating and drinking utensils are simple ways to help prevent the spread of RSV infection. There is currently no vaccine for RSV. Centers for Disease Control and Prevention

  16. Hepatitis Virus Infections in Poultry.

    PubMed

    Yugo, Danielle M; Hauck, Ruediger; Shivaprasad, H L; Meng, Xiang-Jin

    2016-09-01

    Viral hepatitis in poultry is a complex disease syndrome caused by several viruses belonging to different families including avian hepatitis E virus (HEV), duck hepatitis B virus (DHBV), duck hepatitis A virus (DHAV-1, -2, -3), duck hepatitis virus Types 2 and 3, fowl adenoviruses (FAdV), and turkey hepatitis virus (THV). While these hepatitis viruses share the same target organ, the liver, they each possess unique clinical and biological features. In this article, we aim to review the common and unique features of major poultry hepatitis viruses in an effort to identify the knowledge gaps and aid the prevention and control of poultry viral hepatitis. Avian HEV is an Orthohepevirus B in the family Hepeviridae that naturally infects chickens and consists of three distinct genotypes worldwide. Avian HEV is associated with hepatitis-splenomegaly syndrome or big liver and spleen disease in chickens, although the majority of the infected birds are subclinical. Avihepadnaviruses in the family of Hepadnaviridae have been isolated from ducks, snow geese, white storks, grey herons, cranes, and parrots. DHBV evolved with the host as a noncytopathic form without clinical signs and rarely progressed to chronicity. The outcome for DHBV infection varies by the host's ability to elicit an immune response and is dose and age dependent in ducks, thus mimicking the pathogenesis of human hepatitis B virus (HBV) infections and providing an excellent animal model for human HBV. DHAV is a picornavirus that causes a highly contagious virus infection in ducks with up to 100% flock mortality in ducklings under 6 wk of age, while older birds remain unaffected. The high morbidity and mortality has an economic impact on intensive duck production farming. Duck hepatitis virus Types 2 and 3 are astroviruses in the family of Astroviridae with similarity phylogenetically to turkey astroviruses, implicating the potential for cross-species infections between strains. Duck astrovirus (DAstV) causes

  17. Gene repertoire of amoeba-associated giant viruses.

    PubMed

    Colson, Philippe; Raoult, Didier

    2010-01-01

    Acanthamoeba polyphaga mimivirus, Marseillevirus, and Sputnik, a virophage, are intra-amoebal viruses that have been isolated from water collected in cooling towers. They have provided fascinating data and have raised exciting questions about viruses definition and evolution. Mimivirus and Marseillevirus have been classified in the nucleo-cytoplasmic large DNA viruses (NCLDVs) class. Their genomes are the largest and fifth largest viral genomes sequenced so far. The gene repertoire of these amoeba-associated viruses can be divided into four groups: the core genome, genes acquired by lateral gene transfer, duplicated genes, and ORFans. Open reading frames (ORFs) that have homologs in the NCLDVs core gene set represent 2.9 and 6.1% of the Mimivirus and Marseillevirus gene contents, respectively. A substantial proportion of the Mimivirus, Marseillevirus and Sputnik ORFs exhibit sequence similarities to homologs found in bacteria, archaea, eukaryotes or viruses. The large amount of chimeric genes in these viral genomes might have resulted from acquisitions by lateral gene transfers, implicating sympatric bacteria and viruses with an intra-amoebal lifestyle. In addition, lineage-specific gene expansion may have played a major role in the genome shaping. Altogether, the data so far accumulated on amoeba-associated giant viruses are a powerful incentive to isolate and study additional strains to gain better understanding of their pangenome. PMID:20551685

  18. Probiotics in respiratory virus infections.

    PubMed

    Lehtoranta, L; Pitkäranta, A; Korpela, R

    2014-08-01

    Viral respiratory infections are the most common diseases in humans. A large range of etiologic agents challenge the development of efficient therapies. Research suggests that probiotics are able to decrease the risk or duration of respiratory infection symptoms. However, the antiviral mechanisms of probiotics are unclear. The purpose of this paper is to review the current knowledge on the effects of probiotics on respiratory virus infections and to provide insights on the possible antiviral mechanisms of probiotics. A PubMed and Scopus database search was performed up to January 2014 using appropriate search terms on probiotic and respiratory virus infections in cell models, in animal models, and in humans, and reviewed for their relevance. Altogether, thirty-three clinical trials were reviewed. The studies varied highly in study design, outcome measures, probiotics, dose, and matrices used. Twenty-eight trials reported that probiotics had beneficial effects in the outcome of respiratory tract infections (RTIs) and five showed no clear benefit. Only eight studies reported investigating viral etiology from the respiratory tract, and one of these reported a significant decrease in viral load. Based on experimental studies, probiotics may exert antiviral effects directly in probiotic-virus interaction or via stimulation of the immune system. Although probiotics seem to be beneficial in respiratory illnesses, the role of probiotics on specific viruses has not been investigated sufficiently. Due to the lack of confirmatory studies and varied data available, more randomized, double-blind, and placebo-controlled trials in different age populations investigating probiotic dose response, comparing probiotic strains/genera, and elucidating the antiviral effect mechanisms are necessary. PMID:24638909

  19. Giant Magnetoresistance-based Biosensor for Detection of Influenza A Virus

    PubMed Central

    Krishna, Venkatramana D.; Wu, Kai; Perez, Andres M.; Wang, Jian-Ping

    2016-01-01

    We have developed a simple and sensitive method for the detection of influenza A virus based on giant magnetoresistance (GMR) biosensor. This assay employs monoclonal antibodies to viral nucleoprotein (NP) in combination with magnetic nanoparticles (MNPs). Presence of influenza virus allows the binding of MNPs to the GMR sensor and the binding is proportional to the concentration of virus. Binding of MNPs onto the GMR sensor causes change in the resistance of sensor, which is measured in a real time electrical readout. GMR biosensor detected as low as 1.5 × 102 TCID50/mL virus and the signal intensity increased with increasing concentration of virus up to 1.0 × 105 TCID50/mL. This study showed that the GMR biosensor assay is relevant for diagnostic application since the virus concentration in nasal samples of influenza virus infected swine was reported to be in the range of 103 to 105 TCID50/mL. PMID:27065967

  20. Varicella Zoster Virus Infection in Granulomatous Arteritis of the Aorta.

    PubMed

    Gilden, Don; White, Teresa; Boyer, Philip J; Galetta, Kristin M; Hedley-Whyte, E Tessa; Frank, Meredith; Holmes, Dawn; Nagel, Maria A

    2016-06-15

    Granulomatous arteritis characterizes the pathology of giant cell arteritis, granulomatous aortitis, and intracerebral varicella zoster virus (VZV) vasculopathy. Because intracerebral VZV vasculopathy and giant cell arteritis are strongly associated with productive VZV infection in cerebral and temporal arteries, respectively, we evaluated human aortas for VZV antigen and VZV DNA. Using 3 different anti-VZV antibodies, we identified VZV antigen in 11 of 11 aortas with pathologically verified granulomatous arteritis, in 1 of 1 cases of nongranulomatous arteritis, and in 5 of 18 control aortas (28%) obtained at autopsy. The presence of VZV antigen in granulomatous aortitis was highly significant (P = .0001) as compared to control aortas, in which VZV antigen was never associated with pathology, indicating subclinical reactivation. VZV DNA was found in most aortas containing VZV antigen. The frequent clinical, radiological, and pathological aortic involvement in patients with giant cell arteritis correlates with the significant detection of VZV in granulomatous aortitis. PMID:27037084

  1. Pediatric human immunodeficiency virus infection.

    PubMed Central

    Domachowske, J B

    1996-01-01

    In the past decade, an increase in pediatric human immunodeficiency virus (HIV) infection has had a substantial impact on childhood morbidity and mortality worldwide. The vertical transmission of HIV from mother to infant accounts for the vast majority of these cases. Identification of HIV-infected pregnant women needs to be impoved so that appropriate therapy can be initiated for both mothers and infants. While recent data demonstrate a dramatic decrease in HIV transmission from a subset of women treated with zidovudine during pregnancy, further efforts at reducing transmission are desperately needed. This review focuses on vertically transmitted HIV infection in children, its epidemiology, diagnostic criteria, natural history, and clinical manifestations including infectious and noninfectious complications. An overview of the complex medical management of these children ensues, including the use of antiretroviral therapy. Opportunistic infection prophylaxis is reviewed, along with the important role of other supportive therapies. PMID:8894346

  2. Immunosuppression During Influenza Virus Infection

    PubMed Central

    Kantzler, G. B.; Lauteria, S. F.; Cusumano, C. L.; Lee, J. D.; Ganguly, R.; Waldman, R. H.

    1974-01-01

    The effects of a live attenuated influenza vaccine and subsequent challenge with virulent influenza virus on the delayed hypersensitivity skin test, and the in vitro response of lymphocytes were evaluated. Volunteers were skin tested before and after administration of vaccine or placebo and challenge with PPD (a purified protein derivative of Mycobacterium tuberculosis), candida, mumps, and trichophytin, and their lymphocytes were tested for [3H]thymidine uptake in response to phytohemagglutin. Of eight volunteers who showed evidence of viral replication after administration of the attenuated vaccine, four had a significant diminution in their skin test response, whereas 8 of 13 volunteers infected with virulent influenza virus showed a diminution. Of the 21 volunteers who were infected with either attenuated or virulent influenza virus, 12 showed suppression of their phytohemagglutin response. None of the volunteers who were given placebo vaccine, or who showed no evidence for viral replication after immunization or challenge, had a suppression of their skin test or phytohemagglutin responses. Although most of the infected volunteers demonstrated suppression of their T-cell function, there was no evidence of a similar suppression of B-cell function. PMID:16558116

  3. Giant virus in the sea: Extending the realm of Megaviridae to Viridiplantae.

    PubMed

    Claverie, Jean-Michel

    2013-11-01

    The viral nature of the first "giant virus," Mimivirus, was realized in 2003, 10 y after its initial isolation from the water of a cooling tower in Bradford, UK. Soon after its genome was sequenced, the mining of the Global Ocean Sampling environmental sequence database revealed that the closest relatives of Mimivirus, only known to infect Acanthamoeba, were to be found in the sea. These predicted marine Mimivirus relatives remained elusive until 2010, with the first genomic characterization of a virus infecting a heterotrophic unicellular eukaryote, the microflagellate grazer Cafeteria roenbergensis. The genome analysis of a virus (PgV) infecting the common unicellular algae Phaeocystis globosa now shows that it is a bona fide member of the Mimivirus family (i.e., the Megaviridae), extending the realm of these giant viruses to abundant blooming phytoplankton species. Despite its smaller genome size (460 kb encoding 434 proteins), PgV exhibits the most intriguing feature of the previously characterized Megaviridae: an associated virophage. However, the 19-kb virophage genome, devoid of a capsid gene, is packaged in the PgV particle and propagated as a "viral plasmid," the first ever described. The PgV genome also exhibits the duplication of "core genes," normally present as single copies and a putative new type of mobile element. In a DNA polymerase phylogeny including representatives of the three cellular domains, PgV and the other Megaviridae cluster into their own clade deeply branching between domains Archaea and Eukarya domains, thus exhibiting the topology of a fourth domain in the Tree of Life. PMID:24563700

  4. Avian Influenza A Virus Infections in Humans

    MedlinePlus

    ... Research Making a Candidate Vaccine Virus Related Links Influenza Types Seasonal Avian Swine Variant Pandemic Other Get ... Submit What's this? Submit Button Past Newsletters Avian Influenza A Virus Infections in Humans Language: English Españ ...

  5. Uveitis Associated with Zika Virus Infection.

    PubMed

    Furtado, João M; Espósito, Danillo L; Klein, Taline M; Teixeira-Pinto, Tomás; da Fonseca, Benedito A

    2016-07-28

    An adult patient recovered from acute Zika virus infection, but ocular symptoms subsequently developed. Anterior uveitis was diagnosed, and Zika virus was identified in the aqueous humor. PMID:27332784

  6. Evolution of double-stranded DNA viruses of eukaryotes: from bacteriophages to transposons to giant viruses

    PubMed Central

    Koonin, Eugene V; Krupovic, Mart; Yutin, Natalya

    2015-01-01

    Diverse eukaryotes including animals and protists are hosts to a broad variety of viruses with double-stranded (ds) DNA genomes, from the largest known viruses, such as pandoraviruses and mimiviruses, to tiny polyomaviruses. Recent comparative genomic analyses have revealed many evolutionary connections between dsDNA viruses of eukaryotes, bacteriophages, transposable elements, and linear DNA plasmids. These findings provide an evolutionary scenario that derives several major groups of eukaryotic dsDNA viruses, including the proposed order “Megavirales,” adenoviruses, and virophages from a group of large virus-like transposons known as Polintons (Mavericks). The Polintons have been recently shown to encode two capsid proteins, suggesting that these elements lead a dual lifestyle with both a transposon and a viral phase and should perhaps more appropriately be named polintoviruses. Here, we describe the recently identified evolutionary relationships between bacteriophages of the family Tectiviridae, polintoviruses, adenoviruses, virophages, large and giant DNA viruses of eukaryotes of the proposed order “Megavirales,” and linear mitochondrial and cytoplasmic plasmids. We outline an evolutionary scenario under which the polintoviruses were the first group of eukaryotic dsDNA viruses that evolved from bacteriophages and became the ancestors of most large DNA viruses of eukaryotes and a variety of other selfish elements. Distinct lines of origin are detectable only for herpesviruses (from a different bacteriophage root) and polyoma/papillomaviruses (from single-stranded DNA viruses and ultimately from plasmids). Phylogenomic analysis of giant viruses provides compelling evidence of their independent origins from smaller members of the putative order “Megavirales,” refuting the speculations on the evolution of these viruses from an extinct fourth domain of cellular life. PMID:25727355

  7. Neuropathology of Zika Virus Infection

    PubMed Central

    Solomon, Isaac H; Milner, Danny A; Folkerth, Rebecca D

    2016-01-01

    Zika virus (ZIKV) is a member of the Flaviviridae family that had been associated only with mild disease prior to the 2015 outbreak in Brazil. A dramatic increase in reported cases of microcephaly and Guillain-Barré syndrome during this time prompted significant research into possible associations with ZIKV and its neurotropic properties. Infection of neural progenitor cells and organoids have been shown to induce apoptosis and dysregulation of growth, and mouse studies have demonstrated viral replication in brain tissue in adults, as well as vertical transmission resulting in embryonic brain abnormalities. Large case series of clinical and radiological findings of congenital ZIKV infection have begun to be published; however, pathology reports have been limited to two case reports and two small case series. Thus far, the findings have largely been restricted to the brain and include diffuse grey and white matter involvement consisting of dystrophic calcifications, gliosis, microglial nodules, neuronophagia, and scattered lymphocytes. Mild chronic villitis was observed in the placental tissue in some cases, and the remaining organs were essentially uninvolved. Larger, systematic studies, including correlation of histological findings with gestational age at the time of maternal infection, will be required to determine the full range of Zika virus-induced abnormalities and to help guide future clinical decision making. PMID:27525286

  8. CELLULAR PATHOLOGY OF A GRANULOSIS VIRUS INFECTION

    EPA Science Inventory

    Nuclear and cytoplasmic ultrastructural changes were examined in Spodoptera frugiperda (SF) larval fat body cells infected with granulosis virus (GV). Soon after infection necleocapsidlike structures were observed within the nucleus associated with nuclear pores. The earliest cel...

  9. Zika Virus Infection and Zika Fever: Frequently Asked Questions

    MedlinePlus

    ... Updated: 25 March 2016 ABOUT ZIKA What is Zika virus infection? Zika virus infection is caused by the ... possible to characterize the disease better. How is Zika virus transmitted? Zika virus is transmitted to people through ...

  10. Current Management of Hepatitis C Virus Infection.

    PubMed

    Mah'moud, Mitchell A

    2016-01-01

    At least 3 million people in the United States are infected with hepatitis C virus (HCV) infection. Unfortunately, 75% of infected individuals remain undiagnosed and untreated, putting them at risk of advanced liver disease. Because the majority of infected individuals are baby boomers, many societies and organizations recommend HCV screening of persons born between 1945 and 1965. PMID:27154887

  11. Modeling Zika Virus Infection in Mice.

    PubMed

    Rossi, Shannan L; Vasilakis, Nikos

    2016-07-01

    Understanding the link between Zika virus (ZIKV) infection and microcephaly requires in vivo models of ZIKV infection in pregnant adults and fetuses. Three studies recently generated such mouse models of ZIKV infection, which corroborate previous in vitro evidence linking ZIKV infection and apoptosis induction in neurons and progenitors to microcephaly. PMID:27392219

  12. The greasy response to virus infections

    PubMed Central

    Tanner, Lukas Bahati; Lee, Benhur

    2013-01-01

    Previews Virus replication requires lipid metabolism, but how lipids mediate virus infection remains obscure. In this issue, Amini-Bavil-Olyaee et al. (2013) reveal that IFITM proteins disturb cholesterol homeostasis to block virus entry. Previously in Cell, Morita and colleagues (2013) showed the antiviral potency of the lipid mediator protectin D1. PMID:23601099

  13. Systems analysis of West Nile virus infection.

    PubMed

    Suthar, Mehul S; Pulendran, Bali

    2014-06-01

    Emerging and re-emerging mosquito-borne viruses continue to pose a significant threat to human health throughout the world. Over the past decade, West Nile virus (WNV), Dengue virus (DENV), and Chikungunya virus (CHIKV), have caused annual epidemics of virus-induced encephalitis, hemorrhagic fever\\shock syndromes, and arthritis, respectively. Currently, no specific antiviral therapies or vaccines exist for use in humans to combat or prevent these viral infections. Thus, there is a pressing need to define the virus-host interactions that govern immunity and infection outcome. Recent technological breakthroughs in 'omics' resources and high-throughput based assays are beginning to accelerate antiviral drug discovery and improve on current strategies for vaccine design. In this review, we highlight studies with WNV and discuss how traditional and systems biological approaches are being used to rapidly identify novel host targets for therapeutic intervention and develop a deeper conceptual understanding of the host response to virus infection. PMID:24851811

  14. Giant Virus Megavirus chilensis Encodes the Biosynthetic Pathway for Uncommon Acetamido Sugars*

    PubMed Central

    Piacente, Francesco; De Castro, Cristina; Jeudy, Sandra; Molinaro, Antonio; Salis, Annalisa; Damonte, Gianluca; Bernardi, Cinzia; Abergel, Chantal; Tonetti, Michela G.

    2014-01-01

    Giant viruses mimicking microbes, by the sizes of their particles and the heavily glycosylated fibrils surrounding their capsids, infect Acanthamoeba sp., which are ubiquitous unicellular eukaryotes. The glycans on fibrils are produced by virally encoded enzymes, organized in gene clusters. Like Mimivirus, Megavirus glycans are mainly composed of virally synthesized N-acetylglucosamine (GlcNAc). They also contain N-acetylrhamnosamine (RhaNAc), a rare sugar; the enzymes involved in its synthesis are encoded by a gene cluster specific to Megavirus close relatives. We combined activity assays on two enzymes of the pathway with mass spectrometry and NMR studies to characterize their specificities. Mg534 is a 4,6-dehydratase 5-epimerase; its three-dimensional structure suggests that it belongs to a third subfamily of inverting dehydratases. Mg535, next in the pathway, is a bifunctional 3-epimerase 4-reductase. The sequential activity of the two enzymes leads to the formation of UDP-l-RhaNAc. This study is another example of giant viruses performing their glycan synthesis using enzymes different from their cellular counterparts, raising again the question of the origin of these pathways. PMID:25035429

  15. Giant virus Megavirus chilensis encodes the biosynthetic pathway for uncommon acetamido sugars.

    PubMed

    Piacente, Francesco; De Castro, Cristina; Jeudy, Sandra; Molinaro, Antonio; Salis, Annalisa; Damonte, Gianluca; Bernardi, Cinzia; Abergel, Chantal; Tonetti, Michela G

    2014-08-29

    Giant viruses mimicking microbes, by the sizes of their particles and the heavily glycosylated fibrils surrounding their capsids, infect Acanthamoeba sp., which are ubiquitous unicellular eukaryotes. The glycans on fibrils are produced by virally encoded enzymes, organized in gene clusters. Like Mimivirus, Megavirus glycans are mainly composed of virally synthesized N-acetylglucosamine (GlcNAc). They also contain N-acetylrhamnosamine (RhaNAc), a rare sugar; the enzymes involved in its synthesis are encoded by a gene cluster specific to Megavirus close relatives. We combined activity assays on two enzymes of the pathway with mass spectrometry and NMR studies to characterize their specificities. Mg534 is a 4,6-dehydratase 5-epimerase; its three-dimensional structure suggests that it belongs to a third subfamily of inverting dehydratases. Mg535, next in the pathway, is a bifunctional 3-epimerase 4-reductase. The sequential activity of the two enzymes leads to the formation of UDP-l-RhaNAc. This study is another example of giant viruses performing their glycan synthesis using enzymes different from their cellular counterparts, raising again the question of the origin of these pathways. PMID:25035429

  16. RNA Viruses Infecting Pest Insects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    RNA viruses are viruses whose genetic material is ribonucleic acid (RNA). RNA viruses may be double or single-stranded based on the type of RNA they contain. Single-stranded RNA viruses can be further grouped into negative sense or positive-sense viruses according to the polarity of their RNA. Fur...

  17. Hendra Virus Infection in Dog, Australia, 2013

    PubMed Central

    Gabor, Melinda; Poe, Ian; Neale, Kristie; Chaffey, Kim; Finlaison, Deborah S.; Gu, Xingnian; Hick, Paul M.; Read, Andrew J.; Wright, Therese; Middleton, Deborah

    2015-01-01

    Hendra virus occasionally causes severe disease in horses and humans. In Australia in 2013, infection was detected in a dog that had been in contact with an infected horse. Abnormalities and viral RNA were found in the dog’s kidney, brain, lymph nodes, spleen, and liver. Dogs should be kept away from infected horses. PMID:26583697

  18. The Epidemiology of Human Immunodeficiency Virus Infection.

    ERIC Educational Resources Information Center

    Glasner, Peter D.; Kaslow, Richard A.

    1990-01-01

    Reviews epidemiology and natural history of human immunodeficiency virus-Type 1 (HIV-1) infection. Discusses early and late clinical manifestations, diagnosis of infection, incubation and latency periods, and survival time. Reviews data from published literature on distribution of HIV infection in adult United States population and factors that…

  19. Hendra Virus Infection in Dog, Australia, 2013.

    PubMed

    Kirkland, Peter D; Gabor, Melinda; Poe, Ian; Neale, Kristie; Chaffey, Kim; Finlaison, Deborah S; Gu, Xingnian; Hick, Paul M; Read, Andrew J; Wright, Therese; Middleton, Deborah

    2015-12-01

    Hendra virus occasionally causes severe disease in horses and humans. In Australia in 2013, infection was detected in a dog that had been in contact with an infected horse. Abnormalities and viral RNA were found in the dog's kidney, brain, lymph nodes, spleen, and liver. Dogs should be kept away from infected horses. PMID:26583697

  20. Influenza Virus Infection of Marine Mammals.

    PubMed

    Fereidouni, Sasan; Munoz, Olga; Von Dobschuetz, Sophie; De Nardi, Marco

    2016-03-01

    Interspecies transmission may play a key role in the evolution and ecology of influenza A viruses. The importance of marine mammals as hosts or carriers of potential zoonotic pathogens such as highly pathogenic H5 and H7 influenza viruses is not well understood. The fact that influenza viruses are some of the few zoonotic pathogens known to have caused infection in marine mammals, evidence for direct transmission of influenza A virus H7N7 subtype from seals to man, transmission of pandemic H1N1 influenza viruses to seals and also limited evidence for long-term persistence of influenza B viruses in seal populations without significant genetic change, makes monitoring of influenza viruses in marine mammal populations worth being performed. In addition, such monitoring studies could be a great tool to better understand the ecology of influenza viruses in nature. PMID:25231137

  1. Interferon-γ Inhibits Ebola Virus Infection

    PubMed Central

    Rhein, Bethany A.; Powers, Linda S.; Rogers, Kai; Anantpadma, Manu; Singh, Brajesh K.; Sakurai, Yasuteru; Bair, Thomas; Miller-Hunt, Catherine; Sinn, Patrick; Davey, Robert A.

    2015-01-01

    Ebola virus outbreaks, such as the 2014 Makona epidemic in West Africa, are episodic and deadly. Filovirus antivirals are currently not clinically available. Our findings suggest interferon gamma, an FDA-approved drug, may serve as a novel and effective prophylactic or treatment option. Using mouse-adapted Ebola virus, we found that murine interferon gamma administered 24 hours before or after infection robustly protects lethally-challenged mice and reduces morbidity and serum viral titers. Furthermore, we demonstrated that interferon gamma profoundly inhibits Ebola virus infection of macrophages, an early cellular target of infection. As early as six hours following in vitro infection, Ebola virus RNA levels in interferon gamma-treated macrophages were lower than in infected, untreated cells. Addition of the protein synthesis inhibitor, cycloheximide, to interferon gamma-treated macrophages did not further reduce viral RNA levels, suggesting that interferon gamma blocks life cycle events that require protein synthesis such as virus replication. Microarray studies with interferon gamma-treated human macrophages identified more than 160 interferon-stimulated genes. Ectopic expression of a select group of these genes inhibited Ebola virus infection. These studies provide new potential avenues for antiviral targeting as these genes that have not previously appreciated to inhibit negative strand RNA viruses and specifically Ebola virus infection. As treatment of interferon gamma robustly protects mice from lethal Ebola virus infection, we propose that interferon gamma should be further evaluated for its efficacy as a prophylactic and/or therapeutic strategy against filoviruses. Use of this FDA-approved drug could rapidly be deployed during future outbreaks. PMID:26562011

  2. Interferon-γ Inhibits Ebola Virus Infection.

    PubMed

    Rhein, Bethany A; Powers, Linda S; Rogers, Kai; Anantpadma, Manu; Singh, Brajesh K; Sakurai, Yasuteru; Bair, Thomas; Miller-Hunt, Catherine; Sinn, Patrick; Davey, Robert A; Monick, Martha M; Maury, Wendy

    2015-01-01

    Ebola virus outbreaks, such as the 2014 Makona epidemic in West Africa, are episodic and deadly. Filovirus antivirals are currently not clinically available. Our findings suggest interferon gamma, an FDA-approved drug, may serve as a novel and effective prophylactic or treatment option. Using mouse-adapted Ebola virus, we found that murine interferon gamma administered 24 hours before or after infection robustly protects lethally-challenged mice and reduces morbidity and serum viral titers. Furthermore, we demonstrated that interferon gamma profoundly inhibits Ebola virus infection of macrophages, an early cellular target of infection. As early as six hours following in vitro infection, Ebola virus RNA levels in interferon gamma-treated macrophages were lower than in infected, untreated cells. Addition of the protein synthesis inhibitor, cycloheximide, to interferon gamma-treated macrophages did not further reduce viral RNA levels, suggesting that interferon gamma blocks life cycle events that require protein synthesis such as virus replication. Microarray studies with interferon gamma-treated human macrophages identified more than 160 interferon-stimulated genes. Ectopic expression of a select group of these genes inhibited Ebola virus infection. These studies provide new potential avenues for antiviral targeting as these genes that have not previously appreciated to inhibit negative strand RNA viruses and specifically Ebola virus infection. As treatment of interferon gamma robustly protects mice from lethal Ebola virus infection, we propose that interferon gamma should be further evaluated for its efficacy as a prophylactic and/or therapeutic strategy against filoviruses. Use of this FDA-approved drug could rapidly be deployed during future outbreaks. PMID:26562011

  3. Dengue Virus Infection Perturbs Lipid Homeostasis in Infected Mosquito Cells

    SciTech Connect

    Perera, Rushika M.; Riley, Catherine; Isaac, Georgis; Hopf- Jannasch, Amber; Moore, Ronald J.; Weitz, Karl K.; Pasa-Tolic, Ljiljana; Metz, Thomas O.; Adamec, Jiri; Kuhn, Richard J.

    2012-03-22

    Dengue virus causes {approx}50-100 million infections per year and thus is considered one of the most aggressive arthropod-borne human pathogen worldwide. During its replication, dengue virus induces dramatic alterations in the intracellular membranes of infected cells. This phenomenon is observed both in human and vector-derived cells. Using high-resolution mass spectrometry of mosquito cells, we show that this membrane remodeling is directly linked to a unique lipid repertoire induced by dengue virus infection. Specifically, 15% of the metabolites detected were significantly different between DENV infected and uninfected cells while 85% of the metabolites detected were significantly different in isolated replication complex membranes. Furthermore, we demonstrate that intracellular lipid redistribution induced by the inhibition of fatty acid synthase, the rate-limiting enzyme in lipid biosynthesis, is sufficient for cell survival but is inhibitory to dengue virus replication. Lipids that have the capacity to destabilize and change the curvature of membranes as well as lipids that change the permeability of membranes are enriched in dengue virus infected cells. Several sphingolipids and other bioactive signaling molecules that are involved in controlling membrane fusion, fission, and trafficking as well as molecules that influence cytoskeletal reorganization are also up regulated during dengue infection. These observations shed light on the emerging role of lipids in shaping the membrane and protein environments during viral infections and suggest membrane-organizing principles that may influence virus-induced intracellular membrane architecture.

  4. The 474-Kilobase-Pair Complete Genome Sequence of CeV-01B, a Virus Infecting Haptolina (Chrysochromulina) ericina (Prymnesiophyceae)

    PubMed Central

    Gallot-Lavallée, Lucie; Pagarete, António; Legendre, Matthieu; Santini, Sebastien; Sandaa, Ruth-Anne; Himmelbauer, Heinz; Ogata, Hiroyuki; Bratbak, Gunnar

    2015-01-01

    We report the complete genome sequence of CeV-01B, a large double-stranded DNA virus infecting the unicellular marine phytoplankton Haptolina (formerly Chrysochromulina) ericina. CeV-01B and its closest relative Phaeocystis globosa virus define an emerging subclade of the Megaviridae family with smaller genomes and particles than the originally described giant Mimiviridae infecting Acanthamoeba. PMID:26634761

  5. Human immunodeficiency virus infection and pneumothorax

    PubMed Central

    Terzi, Eirini; Zarogoulidis, Konstantinos; Kougioumtzi, Ioanna; Dryllis, Georgios; Kioumis, Ioannis; Pitsiou, Georgia; Machairiotis, Nikolaos; Katsikogiannis, Nikolaos; Tsiouda, Theodora; Madesis, Athanasios; Karaiskos, Theodoros

    2014-01-01

    Pneumothorax is a serious and relatively frequent complication of human immunodeficiency virus (HIV) infection that may associate with increased morbidity and mortality and may prove difficult to manage, especially in patients with acquired immunodeficiency syndrome (AIDS). PMID:25337392

  6. METHODS USED TO STUDY RESPIRATORY VIRUS INFECTION

    PubMed Central

    Flaño, Emilio; Jewell, Nancy A.; Durbin, Russell K.; Durbin, Joan E.

    2009-01-01

    This unit describes protocols for infecting the mouse respiratory tract, and assaying virus replication and host response in the lung. Respiratory infections are the leading cause of acute illness worldwide, affecting mostly infants and children in developing countries. The purpose of this unit is to provide the readers with a basic strategy and protocols to study the pathogenesis and immunology of respiratory virus infection using the mouse as an animal model. The procedures include: (i) basic techniques for mouse infection, tissue sampling and preservation, (ii) determination of viral titers, isolation and analysis of lymphocytes and dendritic cells using flow-cytometry, and (iii) lung histology, immunohistochemistry and in situ hybridization. PMID:19499505

  7. Life-Threatening Sochi Virus Infections, Russia.

    PubMed

    Kruger, Detlev H; Tkachenko, Evgeniy A; Morozov, Vyacheslav G; Yunicheva, Yulia V; Pilikova, Olga M; Malkin, Gennadiy; Ishmukhametov, Aydar A; Heinemann, Patrick; Witkowski, Peter T; Klempa, Boris; Dzagurova, Tamara K

    2015-12-01

    Sochi virus was recently identified as a new hantavirus genotype carried by the Black Sea field mouse, Apodemus ponticus. We evaluated 62 patients in Russia with Sochi virus infection. Most clinical cases were severe, and the case-fatality rate was as high as 14.5%. PMID:26584463

  8. Life-Threatening Sochi Virus Infections, Russia

    PubMed Central

    Tkachenko, Evgeniy A.; Morozov, Vyacheslav G.; Yunicheva, Yulia V.; Pilikova, Olga M.; Malkin, Gennadiy; Ishmukhametov, Aydar A.; Heinemann, Patrick; Witkowski, Peter T.; Klempa, Boris; Dzagurova, Tamara K.

    2015-01-01

    Sochi virus was recently identified as a new hantavirus genotype carried by the Black Sea field mouse, Apodemus ponticus. We evaluated 62 patients in Russia with Sochi virus infection. Most clinical cases were severe, and the case-fatality rate was as high as 14.5%. PMID:26584463

  9. Nipah Virus Infection in Dogs, Malaysia, 1999

    PubMed Central

    Alim, Asiah N.M.; Bunning, Michel L.; Lee, Ong Bee; Wagoner, Kent D.; Amman, Brian R.; Stockton, Patrick C.; Ksiazek, Thomas G.

    2009-01-01

    The 1999 outbreak of Nipah virus encephalitis in humans and pigs in Peninsular Malaysia ended with the evacuation of humans and culling of pigs in the epidemic area. Serologic screening showed that, in the absence of infected pigs, dogs were not a secondary reservoir for Nipah virus. PMID:19523300

  10. Chronic Hepatitis E Virus Infection and Treatment

    PubMed Central

    Kamar, Nassim; Izopet, Jacques; Dalton, Harry R.

    2013-01-01

    It is now well accepted that hepatitis E virus (HEV) infection can induce chronic hepatitis and cirrhosis in immunosuppressed patients. Chronic genotype-3 HEV infections were first reported in patients with a solid-organ transplant. Thereafter, cases of chronic HEV infection have been reported in patients with hematological disease and in those who are human immunodeficiency virus (HIV)-positive. HEV-associated extra-hepatic manifestations, including neurological symptoms, kidney injuries, and hematological disorders, have been also reported. In transplant patients, reducing the dosage of immunosuppressive drugs allows the virus to be cleared in some patients. In the remaining patients, as well as hematological patients and patients who are HIV-positive, anti-viral therapies, such as pegylated interferon and ribavirin, have been found to be efficient in eradicating HEV infection. This review summarizes our current knowledge of chronic HEV infection, its treatment, and the extra-hepatic manifestations induced by HEV. PMID:25755487

  11. Virus-Specific Cellular Response in Hepatitis C Virus Infection.

    PubMed

    Kaźmierczak, Justyna; Caraballo Cortes, Kamila; Bukowska-Ośko, Iwona; Radkowski, Marek

    2016-04-01

    Studies performed on chimpanzees and humans have revealed that strong, multispecific and sustained CD4(+) and CD8(+) T cell immune responses is a major determinant of hepatitis C virus (HCV) clearance. However, spontaneous elimination of the virus occurs in minority of infected individuals and cellular response directed against HCV antigens is not persistent in individuals with chronic infection. This review presents characteristics of the HCV-specific T cell response in patients with different clinical course of infection, including acute and chronic infection, persons who spontaneously eliminated HCV and non-infected subjects exposed to HCV. Detection of HCV-specific response, especially in non-infected subjects exposed to HCV, may be indicative of HCV prevalence in population and rate of spontaneous viral clearance. Understanding the mechanisms and role of HCV-specific cellular immune response would contribute to better understanding of HCV epidemiology, immunopathogenesis and may help to design an effective vaccine. PMID:26429740

  12. Left atrial giant thrombus infected by Escherichia Coli. Case report

    PubMed Central

    Dedeilias, Panagiotis; Roussakis, Antonios; Koletsis, Efstratios N; Zervakis, Dimitrios; Hountis, Panagiotis; Prokakis, Christos; Balaka, Christina; Bolos, Konstantinos

    2008-01-01

    Background Left atrial thrombi are mostly related to mitral valve disease. The differential diagnosis of clots and myxomas in the left atrium is mostly based on echocardiography. Infection of intracardiac thrombi is extremely rare and mostly reported in ventricular clots or aneurysms following myocardial infarction. Case presentation We present the case of a 65 year old female with a history of mitral valve disease and chronic atrial fibrillation who suffered repeated embolic strokes and a giant infected clot in the left atrium. Although the patient underwent prompt surgery with removal of the clot and valve replacement the complication of septic emboli to the CNS led her to death. To the best of our knowledge this is the second report of an infected left atrial thrombus. Conclusion The case is a representative example of a neglected and undertreated patient with catastrophic consequences. Anticoagulant therapy in patients with mitral valve disease and atrial fibrillation should be applied according the currently available guidelines and standards in order to avoid analogous paradigms in the future. Mitral valve substitution should be considered in patients with mitral valve disease presenting thromboembolic complications. Surgery should be considered as the treatment of choice in cases of organized left atrial thrombus and suspected tumor or infected mass. PMID:18433486

  13. DIESEL EXHAUST ENHANCES INFLUENZA VIRUS INFECTIONS IN RESPIRATORY EPITHELIAL CELLS

    EPA Science Inventory

    Several factors, such as age and nutritional status can affect the susceptibility to influenza infections. Moreover, exposure to air pollutants, such as diesel exhaust (DE), has been shown to affect respiratory virus infections in rodent models. Influenza virus primarily infects ...

  14. Molecular Biology of Hepatitis B Virus Infection

    PubMed Central

    Seeger, Christoph; Mason, William S.

    2015-01-01

    Human hepatitis B virus (HBV) is the prototype of a family of small DNA viruses that productively infect hepatocytes, the major cell of the liver, and replicate by reverse transcription of a terminally redundant viral RNA, the pregenome. Upon infection, the circular, partially double-stranded virion DNA is converted in the nucleus to a covalently closed circular DNA (cccDNA) that assembles into a minichromosome, the template for viral mRNA synthesis. Infection of hepatocytes is non-cytopathic. Infection of the liver may be either transient (<6 months) or chronic and life long, depending on the ability of the host immune response to clear the infection. Chronic infections can cause immune mediated liver damage progressing to cirrhosis and hepatocellular carcinoma (HCC). The mechanisms of carcinogenesis are unclear. Antiviral therapies with nucleoside analog inhibitors of viral DNA synthesis delay sequelae, but cannot cure HBV infections due to the persistence of cccDNA in hepatocytes. PMID:25759099

  15. Human Immunodeficiency Virus Type 1 Infection of Neural Xenografts

    NASA Astrophysics Data System (ADS)

    Cvetkovich, Therese A.; Lazar, Eliot; Blumberg, Benjamin M.; Saito, Yoshihiro; Eskin, Thomas A.; Reichman, Richard; Baram, David A.; del Cerro, Coca; Gendelman, Howard E.; del Cerro, Manuel; Epstein, Leon G.

    1992-06-01

    Human immunodeficiency virus type 1 (HIV-1) infection is highly specific for its human host. To study HIV-1 infection of the human nervous system, we have established a small animal model in which second-trimester (11 to 17.5 weeks) human fetal brain or neural retina is transplanted to the anterior chamber of the eye of immunosuppressed adult rats. The human xenografts vascularized, formed a blood-brain barrier, and differentiated, forming neurons and glia. The xenografts were infected with cell-free HIV-1 or with HIV-1-infected human monocytes. Analysis by polymerase chain reaction revealed HIV-1 sequences in DNA from xenograft tissue exposed to HIV-1 virions, and in situ hybridization demonstrated HIV-1 mRNA localized in macrophages and multinucleated giant cells. Pathological damage was observed only in neural xenografts containing HIV-1-infected human monocytes, supporting the hypothesis that these cells mediate neurotoxicity. This small animal model allows the study of direct and indirect effects of HIV-1 infection on developing human fetal neural tissues, and it should prove useful in evaluating antiviral therapies, which must ultimately target HIV-1 infection of the brain.

  16. Acanthamoeba polyphaga mimivirus and other giant viruses: an open field to outstanding discoveries

    PubMed Central

    2014-01-01

    In 2003, Acanthamoeba polyphaga mimivirus (APMV) was first described and began to impact researchers around the world, due to its structural and genetic complexity. This virus founded the family Mimiviridae. In recent years, several new giant viruses have been isolated from different environments and specimens. Giant virus research is in its initial phase and information that may arise in the coming years may change current conceptions of life, diversity and evolution. Thus, this review aims to condense the studies conducted so far about the features and peculiarities of APMV, from its discovery to its clinical relevance. PMID:24976356

  17. Respiratory syncytial virus infection in cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bovine respiratory syncytial virus (bRSV) is a cause of respiratory disease in cattle world-wide. It has an integral role in enzootic pneumonia in young dairy calves and summer pneumonia in nursing beef calves. Furthermore, bRSV infection can predispose calves to secondary bacterial infection by org...

  18. Preventing hospitalizations for respiratory syncytial virus infection

    PubMed Central

    Robinson, Joan L; Le Saux, Nicole

    2015-01-01

    Respiratory syncytial virus infection is the leading cause of lower respiratory tract infections in young children. Palivizumab has minimal impact on RSV hospitilization rates as it is only practical to offer it to the highest risk groups. The present statement reviews the published literature and provides updated recommendations regarding palivizumab use in children in Canada. PMID:26435673

  19. Recurrent lumbosacral herpes simplex virus infection

    PubMed Central

    Vassantachart, Janna M.

    2016-01-01

    We present the case of a 54-year-old white woman with episodic lumbosacral lesions that she had been treating as psoriasis. Evaluation revealed classic herpes simplex virus (HSV) infection. The discussion reviews the significance and potential complications of recurrent lumbosacral HSV infection. PMID:26722168

  20. Economics of bovine leukemia virus infection.

    PubMed

    Pelzer, K D

    1997-03-01

    A herd infected with bovine leukemia virus suffers a direct economic loss due to clinical lymphosarcoma. A major indirect cost associated with infection is restriction of the sale of animals and germplasma to foreign markets. Reports on the economic effects of infection on production have been variable and are reviewed in this article. In order to develop cost-effective bovine leukemia virus control programs, costs associated with the disease, the cost of prevention, and expected economic returns from a program need to be considered. PMID:9071750

  1. Human immunodeficiency virus infection and the liver

    PubMed Central

    Crane, Megan; Iser, David; Lewin, Sharon R

    2012-01-01

    Liver disease in human immunodeficiency virus (HIV)-infected individuals encompasses the spectrum from abnormal liver function tests, liver decompensation, with and without evidence of cirrhosis on biopsy, to non-alcoholic liver disease and its more severe form, non-alcoholic steatohepatitis and hepatocellular cancer. HIV can infect multiple cells in the liver, leading to enhanced intrahepatic apoptosis, activation and fibrosis. HIV can also alter gastro-intestinal tract permeability, leading to increased levels of circulating lipopolysaccharide that may have an impact on liver function. This review focuses on recent changes in the epidemiology, pathogenesis and clinical presentation of liver disease in HIV-infected patients, in the absence of co-infection with hepatitis B virus or hepatitis C virus, with a specific focus on issues relevant to low and middle income countries. PMID:22489261

  2. Infection of phytoplankton by aerosolized marine viruses.

    PubMed

    Sharoni, Shlomit; Trainic, Miri; Schatz, Daniella; Lehahn, Yoav; Flores, Michel J; Bidle, Kay D; Ben-Dor, Shifra; Rudich, Yinon; Koren, Ilan; Vardi, Assaf

    2015-05-26

    Marine viruses constitute a major ecological and evolutionary driving force in the marine ecosystems. However, their dispersal mechanisms remain underexplored. Here we follow the dynamics of Emiliania huxleyi viruses (EhV) that infect the ubiquitous, bloom-forming phytoplankton E. huxleyi and show that EhV are emitted to the atmosphere as primary marine aerosols. Using a laboratory-based setup, we showed that the dynamic of EhV aerial emission is strongly coupled to the host-virus dynamic in the culture media. In addition, we recovered EhV DNA from atmospheric samples collected over an E. huxleyi bloom in the North Atlantic, providing evidence for aerosolization of marine viruses in their natural environment. Decay rate analysis in the laboratory revealed that aerosolized viruses can remain infective under meteorological conditions prevailing during E. huxleyi blooms in the ocean, allowing potential dispersal and infectivity over hundreds of kilometers. Based on the combined laboratory and in situ findings, we propose that atmospheric transport of EhV is an effective transmission mechanism for spreading viral infection over large areas in the ocean. This transmission mechanism may also have an important ecological impact on the large-scale host-virus "arms race" during bloom succession and consequently the turnover of carbon in the ocean. PMID:25964340

  3. Infection of phytoplankton by aerosolized marine viruses

    PubMed Central

    Sharoni, Shlomit; Trainic, Miri; Schatz, Daniella; Lehahn, Yoav; Flores, Michel J.; Bidle, Kay D.; Ben-Dor, Shifra; Rudich, Yinon; Vardi, Assaf

    2015-01-01

    Marine viruses constitute a major ecological and evolutionary driving force in the marine ecosystems. However, their dispersal mechanisms remain underexplored. Here we follow the dynamics of Emiliania huxleyi viruses (EhV) that infect the ubiquitous, bloom-forming phytoplankton E. huxleyi and show that EhV are emitted to the atmosphere as primary marine aerosols. Using a laboratory-based setup, we showed that the dynamic of EhV aerial emission is strongly coupled to the host–virus dynamic in the culture media. In addition, we recovered EhV DNA from atmospheric samples collected over an E. huxleyi bloom in the North Atlantic, providing evidence for aerosolization of marine viruses in their natural environment. Decay rate analysis in the laboratory revealed that aerosolized viruses can remain infective under meteorological conditions prevailing during E. huxleyi blooms in the ocean, allowing potential dispersal and infectivity over hundreds of kilometers. Based on the combined laboratory and in situ findings, we propose that atmospheric transport of EhV is an effective transmission mechanism for spreading viral infection over large areas in the ocean. This transmission mechanism may also have an important ecological impact on the large-scale host–virus “arms race” during bloom succession and consequently the turnover of carbon in the ocean. PMID:25964340

  4. Autoimmune pathogenesis in dengue virus infection.

    PubMed

    Lin, Chiou-Feng; Wan, Shu-Wen; Cheng, Hsien-Jen; Lei, Huan-Yao; Lin, Yee-Shin

    2006-01-01

    The pathogenic mechanisms of dengue hemorrhagic fever and dengue shock syndrome (DHF/DSS) caused by dengue virus (DV) infection remain unresolved. Patients with DHF/DSS are characterized by several manifestations, including severe thrombocytopenia, vascular leakage, and hepatomegaly. In addition to the effect of virus load and virus variation, abnormal immune responses of the host after DV infection may also account for the progression of DHF/DSS. Actually, viral autoimmunity is involved in the pathogenesis of numerous viral infections, such as human immunodeficiency virus, human hepatitis C virus, human cytomegalovirus, herpes simplex virus, Epstein- Barr virus, and DV. In this review, we discuss the implications of autoimmunity in dengue pathogenesis. Antibodies directed against DV nonstructural protein 1 (NS1) showed cross-reactivity with human platelets and endothelial cells, which lead to platelet and endothelial cell damage and inflammatory activation. Based on these findings, we hypothesize that anti-DV NS1 is involved in the pathogenesis of DF and DHF/DSS, and this may provide important information in dengue vaccine development. PMID:16817755

  5. Influenza virus infection, ozone exposure, and fibrogenesis.

    PubMed

    Jakab, G J; Bassett, D J

    1990-05-01

    Oxidant exposure following chemically induced lung injury exacerbates the tendency to develop pulmonary fibrosis. Influenza virus pneumonitis causes severe acute lung damage that, upon resolution, is followed by a persistent alveolitis and parenchymal changes characterized by patchy interstitial pneumonia and collagen deposition in the affected areas. To determine whether oxidant exposure exacerbates the virus-induced alveolitis and residual lung damage, mice were infected by aerosol inhalation with influenza A virus and continuously exposed to 0.5 ppm ozone or ambient air. Noninfected control mice were exposed to either ambient air or ozone. On various days during the first month after infection, groups of mice were sacrificed and their lungs assessed for acute injury (lung lavage albumin, total and differential cell counts, wet/dry ratios, and morphometry). At 30, 60, 90, and 120 days after infection, groups of mice were sacrificed for total and differential lavage cell counts, lung hydroxyproline content, and morphometric analysis. Ozone exposure did not alter the proliferation of virus in the lungs as quantitated by infectious virus titers of lung homogenates at 1, 4, 7, 10, and 15 days after virus infection but mitigated the virus-induced acute lung injury by approximately 50%. After Day 30 a shift in the character of the pulmonary lesions was observed in that continuous exposure to ozone potentiated the postinfluenzal alveolitis and structural changes in the lung parenchyma. Additional studies suggest that the mechanism for the enhanced postinfluenzal lung damage may be related to the oxidant impairing the repair process of the acute influenzal lung damage. These data demonstrate that ozone exposure mitigates acute virus-induced lung injury and potentiates residual lung damage. PMID:2339849

  6. Revisiting the genome packaging in viruses with lessons from the "Giants".

    PubMed

    Chelikani, Venkata; Ranjan, Tushar; Kondabagil, Kiran

    2014-10-01

    Genome encapsidation is an essential step in the life cycle of viruses. Viruses either use some of the most powerful ATP-dependent motors to compel the genetic material into the preformed capsid or make use of the positively charged proteins to bind and condense the negatively charged genome in an energy-independent manner. While the former is a hallmark of large DNA viruses, the latter is commonly seen in small DNA and RNA viruses. Discoveries of many complex giant viruses such as mimivirus, megavirus, pandoravirus, etc., belonging to the nucleo-cytoplasmic large DNA virus (NCLDV) superfamily have changed the perception of genome packaging in viruses. From what little we have understood so far, it seems that the genome packaging mechanism in NCLDVs has nothing in common with other well-characterized viral packaging systems such as the portal-terminase system or the energy-independent system. Recent findings suggest that in giant viruses, the genome segregation and packaging processes are more intricately coupled than those of other viral systems. Interestingly, giant viral packaging systems also seem to possess features that are analogous to bacterial and archaeal chromosome segregation. Although there is a lot of diversity in terms of host range, type of genome, and genome size among viruses, they all seem to use three major types of independent innovations to accomplish genome encapsidation. Here, we have made an attempt to comprehensively review all the known viral genome packaging systems, including the one that is operative in giant viruses, by proposing a simple and expanded classification system that divides the viral packaging systems into three large groups (types I-III) on the basis of the mechanism employed and the relatedness of the major packaging proteins. Known variants within each group have been further classified into subgroups to reflect their unique adaptations. PMID:24998349

  7. The immune response to Nipah virus infection.

    PubMed

    Prescott, Joseph; de Wit, Emmie; Feldmann, Heinz; Munster, Vincent J

    2012-09-01

    Nipah virus has recently emerged as a zoonotic agent that is highly pathogenic in humans. Outbreaks have occurred regularly over the last two decades in South and Southeast Asia, where mortality rates reach as high as 100 %. The natural reservoir of Nipah virus has been identified as bats from the Pteropus family, where infection is largely asymptomatic. Human disease is characterized by both respiratory and encephalitic components, and thus far, no effective vaccine or intervention strategies are available. Little is know about how the immune response of either the reservoir host or incidental hosts responds to infection, and how this immune response is either inadequate or might contribute to disease in the dead-end host. Experimental vaccines strategies have given us some insight into the immunological requirements for protection. This review summarizes our current understanding of the immune response to Nipah virus infection and emphasizes the need for further research. PMID:22669317

  8. Peptide inhibitors of dengue virus and West Nile virus infectivity

    PubMed Central

    Hrobowski, Yancey M; Garry, Robert F; Michael, Scott F

    2005-01-01

    Viral fusion proteins mediate cell entry by undergoing a series of conformational changes that result in virion-target cell membrane fusion. Class I viral fusion proteins, such as those encoded by influenza virus and human immunodeficiency virus (HIV), contain two prominent alpha helices. Peptides that mimic portions of these alpha helices inhibit structural rearrangements of the fusion proteins and prevent viral infection. The envelope glycoprotein (E) of flaviviruses, such as West Nile virus (WNV) and dengue virus (DENV), are class II viral fusion proteins comprised predominantly of beta sheets. We used a physio-chemical algorithm, the Wimley-White interfacial hydrophobicity scale (WWIHS) [1] in combination with known structural data to identify potential peptide inhibitors of WNV and DENV infectivity that target the viral E protein. Viral inhibition assays confirm that several of these peptides specifically interfere with target virus entry with 50% inhibitory concentration (IC50) in the 10 μM range. Inhibitory peptides similar in sequence to domains with a significant WWIHS scores, including domain II (IIb), and the stem domain, were detected. DN59, a peptide corresponding to the stem domain of DENV, inhibited infection by DENV (>99% inhibition of plaque formation at a concentrations of <25 μM) and cross-inhibition of WNV fusion/infectivity (>99% inhibition at <25 μM) was also demonstrated with DN59. However, a potent WNV inhibitory peptide, WN83, which corresponds to WNV E domain IIb, did not inhibit infectivity by DENV. Additional results suggest that these inhibitory peptides are noncytotoxic and act in a sequence specific manner. The inhibitory peptides identified here can serve as lead compounds for the development of peptide drugs for flavivirus infection. PMID:15927084

  9. Parainfluenza Virus 5 Expressing the G Protein of Rabies Virus Protects Mice after Rabies Virus Infection

    PubMed Central

    Huang, Ying; Chen, Zhenhai; Huang, Junhua

    2014-01-01

    Rabies remains a major public health threat around the world. Once symptoms appear, there is no effective treatment to prevent death. In this work, we tested a recombinant parainfluenza virus 5 (PIV5) strain expressing the glycoprotein (G) of rabies (PIV5-G) as a therapy for rabies virus infection: we have found that PIV5-G protected mice as late as 6 days after rabies virus infection. PIV5-G is a promising vaccine for prevention and treatment of rabies virus infection. PMID:25552723

  10. Pathogenesis of human immunodeficiency virus infection.

    PubMed Central

    Levy, J A

    1993-01-01

    The lentivirus human immunodeficiency virus (HIV) causes AIDS by interacting with a large number of different cells in the body and escaping the host immune response against it. HIV is transmitted primarily through blood and genital fluids and to newborn infants from infected mothers. The steps occurring in infection involve an interaction of HIV not only with the CD4 molecule on cells but also with other cellular receptors recently identified. Virus-cell fusion and HIV entry subsequently take place. Following virus infection, a variety of intracellular mechanisms determine the relative expression of viral regulatory and accessory genes leading to productive or latent infection. With CD4+ lymphocytes, HIV replication can cause syncytium formation and cell death; with other cells, such as macrophages, persistent infection can occur, creating reservoirs for the virus in many cells and tissues. HIV strains are highly heterogeneous, and certain biologic and serologic properties determined by specific genetic sequences can be linked to pathogenic pathways and resistance to the immune response. The host reaction against HIV, through neutralizing antibodies and particularly through strong cellular immune responses, can keep the virus suppressed for many years. Long-term survival appears to involve infection with a relatively low-virulence strain that remains sensitive to the immune response, particularly to control by CD8+ cell antiviral activity. Several therapeutic approaches have been attempted, and others are under investigation. Vaccine development has provided some encouraging results, but the observations indicate the major challenge of preventing infection by HIV. Ongoing research is necessary to find a solution to this devastating worldwide epidemic. Images PMID:8464405

  11. Control of viruses infecting grapevine.

    PubMed

    Maliogka, Varvara I; Martelli, Giovanni P; Fuchs, Marc; Katis, Nikolaos I

    2015-01-01

    Grapevine is a high value vegetatively propagated fruit crop that suffers from numerous viruses, including some that seriously affect the profitability of vineyards. Nowadays, 64 viruses belonging to different genera and families have been reported in grapevines and new virus species will likely be described in the future. Three viral diseases namely leafroll, rugose wood, and infectious degeneration are of major economic importance worldwide. The viruses associated with these diseases are transmitted by mealybugs, scale and soft scale insects, or dagger nematodes. Here, we review control measures of the major grapevine viral diseases. More specifically, emphasis is laid on (i) approaches for the production of clean stocks and propagative material through effective sanitation, robust diagnosis, as well as local and regional certification efforts, (ii) the management of vectors of viruses using cultural, biological, and chemical methods, and (iii) the production of resistant grapevines mainly through the application of genetic engineering. The benefits and limitations of the different control measures are discussed with regard to accomplishments and future research directions. PMID:25591880

  12. Marine Viruses that infect Eukaryotic Microalgae.

    PubMed

    Kimura, Kei; Tomaru, Yuji

    2015-01-01

    Marine microalgae, in general, explain large amount of the primary productions on the planet. Their huge biomass through photosynthetic activities is significant to understand the global geochemical cycles. Many researchers are, therefore, focused on studies of marine microalgae, i.e. phytoplankton. Since the first report of high abundance of viruses in the sea at late 1980's, the marine viruses have recognized as an important decreasing factor of its host populations. They seem to be composed of diverse viruses infectious to different organism groups; most of them are considered to be phages infectious to prokaryotes, and viruses infecting microalgae might be ranked in second level. Over the last quarter of a century, the knowledge on marine microalgal viruses has been accumulated in many aspects. Until today, ca. 40 species of marine microalgal viruses have been discovered, including dsDNA, ssDNA, dsRNA and ssRNA viruses. Their features are unique and comprise new ideas and discoveries, indicating that the marine microalgal virus research is still an intriguing unexplored field. In this review, we summarize their basic biology and ecology, and discuss how and what we should research in this area for further progress. PMID:26923956

  13. Adolescents and human immunodeficiency virus infection.

    PubMed

    Anderson, J R

    1992-12-01

    As of March 31, 1992, individuals 13 to 19 years of age had been diagnosed with acquired immunodeficiency syndrome; over one third were diagnosed in the past 2 years alone. Because of the long incubation period from initial infection to acquired immunodeficiency syndrome diagnosis, the majority of young adults with acquired immunodeficiency syndrome were probably initially infected as adolescents. In 1991, 34% of adolescents with acquired immunodeficiency syndrome were female, and their predominant mode of transmission was heterosexual contact. Human immunodeficiency virus seroprevalence studies of adolescents show a male-to-female ratio approaching 1:1, with many human immunodeficiency virus-infected adolescent women identifying none of the standard risk. Factors such as sexual and drug experimentation, risk taking, and sense of invulnerability so characteristic of adolescence put adolescents at special risk for human immunodeficiency virus. There is no published information on if or how clinical manifestations of human immunodeficiency virus disease in adolescents might differ from those seen in adults. Medical care should be broad-based and should include access to clinical trials for new drug treatments. General knowledge levels about acquired immunodeficiency syndrome are high among US adolescents, but behavioral changes have lagged behind. All adolescents should be targeted for intensive education about human immunodeficiency virus along with interventions designed to enhance their general coping, communication, and decision-making skills. PMID:1450349

  14. The neurobiology of varicella zoster virus infection

    PubMed Central

    Gilden, D.; Mahalingam, R.; Nagel, M. A.; Pugazhenthi, S.; Cohrs, R. J.

    2011-01-01

    Varicella zoster virus (VZV) is a neurotropic herpesvirus that infects nearly all humans. Primary infection usually causes chickenpox (varicella), after which virus becomes latent in cranial nerve ganglia, dorsal root ganglia and autonomic ganglia along the entire neuraxis. Although VZV cannot be isolated from human ganglia, nucleic acid hybridization and, later, polymerase chain reaction proved that VZV is latent in ganglia. Declining VZV-specific host immunity decades after primary infection allows virus to reactivate spontaneously, resulting in shingles (zoster) characterized by pain and rash restricted to 1-3 dermatomes. Multiple other serious neurological and ocular disorders also result from VZV reactivation. This review summarizes the current state of knowledge of the clinical and pathological complications of neurological and ocular disease produced by VZV reactivation, molecular aspects of VZV latency, VZV virology and VZV-specific immunity, the role of apoptosis in VZV-induced cell death, and the development of an animal model provided by simian varicella virus infection of monkeys. PMID:21342215

  15. Pathogenesis of Machupo virus infection in primates*

    PubMed Central

    Eddy, G. A.; Scott, S. K.; Wagner, F. S.; Brand, O. M.

    1975-01-01

    Experimental Machupo virus infection of rhesus and cynomolgus monkeys produced a severe illness consisting of an initial clinical phase and a later neurological phase. Cumulative mortality during the two phases was 80% and 95% respectively. Attempts to alter the pathogenesis with decomplementation or immunosuppression resulted in earlier deaths of the monkeys. PMID:182402

  16. Infection of Plants by Tobacco Mosaic Virus.

    ERIC Educational Resources Information Center

    McDaniel, Larry; Maratos, Marina; Farabaugh, Joan

    1998-01-01

    Provides three exercises that introduce high school and college students to a common strain of the tobacco mosaic virus and the study of some basic biological processes. Activities involve inoculation of plants and observing and recording symptom development in infected plants. (DDR)

  17. Mental Status after West Nile Virus Infection

    PubMed Central

    Sadek, Joseph; Pergam, Steven; Echevarria, Leonor A.; Davis, Larry E.; Goade, Diane; Harnar, Joanne; Nofchissey, Robert A.; Sewel, C. Mack; Ettestad, Paul

    2006-01-01

    Mental status after acute West Nile virus infection has not been examined objectively. We compared Telephone Interview for Cognitive Status scores of 116 patients with West Nile fever or West Nile neuroinvasive disease. Mental status was poorer and cognitive complaints more frequent with West Nile neuroinvasive disease (p = 0.005). PMID:16965710

  18. Orf virus infection in sheep or goats.

    PubMed

    Spyrou, V; Valiakos, G

    2015-12-14

    Orf virus, a member of the genus Parapoxvirus, is the causative agent of contagious ecthyma ('Orf'). It is a pathogen with worldwide distribution, causing significant financial losses in livestock production. The disease mainly affects sheep and goats, but various other ruminants and mammals have been reported to be infected as well. It is also a zoonotic disease, affecting mainly people who come in direct or indirect contact with infected animals (e.g. farmers, veterinarians). The disease is usually benign and self-limiting, although in many cases, especially in young animals, it can be persistent and even fatal. Production losses caused by Orf virus are believed to be underestimated, as it is not a notifiable disease. This review of literature presents all latest information regarding the virus; considerations regarding treatment and prevention will be also discussed. PMID:26315771

  19. Lethal Dengue Virus Infection: A Forensic Overview.

    PubMed

    Byard, Roger W

    2016-06-01

    Dengue virus is a single-stranded RNA virus that is a member of the family Flaviviridae, genus Flavivirus. It is usually transmitted by the female Aedes aegypti mosquito. Dengue fever is a febrile illness caused by 1 of 4 serotypes of the virus, which may progress to dengue hemorrhagic fever or dengue shock syndrome. The mortality rate of untreated dengue shock syndrome is more than 20%. The reported incidence has increased 30-fold for the past 50 years with an estimated 50 to 100 million dengue infections globally each year, which includes 22,000 deaths. Because of this rapid increase in numbers, more cases will be seen in forensic mortuaries, with diagnostic problems arising from nonspecific or unusual manifestations. In this review, the clinicopathological features of dengue viral infection are evaluated. Adequate blood and tissue sampling at the time of autopsy is mandatory for successful microbiological identification and characterization. PMID:27093563

  20. Previous infection with a mesogenic strain of Newcastle disease virus affects infection with highly pathogenic avian influenza viruses in chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus (AIV) and Newcastle disease virus (NDV) are two of the most important viruses affecting poultry worldwide, but little is known on the interactions between these two viruses when infecting birds. In a previous study we found that infection of chickens with a mesogenic strain of...

  1. Update on oral herpes virus infections.

    PubMed

    Balasubramaniam, Ramesh; Kuperstein, Arthur S; Stoopler, Eric T

    2014-04-01

    Oral herpes virus infections (OHVIs) are among the most common mucosal disorders encountered by oral health care providers. These infections can affect individuals at any age, from infants to the elderly, and may cause significant pain and dysfunction. Immunosuppressed patients may be at increased risk for serious and potential life-threatening complications caused by OHVIs. Clinicians may have difficulty in diagnosing these infections because they can mimic other conditions of the oral mucosa. This article provides oral health care providers with clinically relevant information regarding etiopathogenesis, diagnosis, and management of OHVIs. PMID:24655522

  2. Atypical Presentations of Respiratory Syncytial Virus Infection

    PubMed Central

    Al-Maskari, Nawal; Mohsin, Jalila; Al-Maani, Amal; Al-Macki, Nabil; Al-Ismaili, Suad

    2016-01-01

    The respiratory syncytial virus (RSV) usually causes a lower respiratory tract infection in affected patients. RSV has also been infrequently linked to extrapulmonary diseases in children. We report four children who had unusually severe clinical manifestations of RSV infections requiring critical care admission. These patients presented to the Royal Hospital, Muscat, Oman, in December 2013 with acute necrotising encephalopathy (ANE), acute fulminant hepatic failure with encephalopathy, pneumatoceles and croup. A unique presentation of ANE has not previously been reported in association with an RSV infection. All patients had a positive outcome and recovered fully with supportive management. PMID:26909220

  3. Modeling Zika Virus Infection in Pregnancy.

    PubMed

    Mysorekar, Indira U; Diamond, Michael S

    2016-08-01

    There were few studies of Zika virus (ZIKV), a flavivirus, until this past year, when large epidemics in the Americas were accompanied by unexpectedly severe clinical manifestations. Infection in pregnant women has emerged as a major global concern because of its linkage to congenital abnormalities including microcephaly, spontaneous abortion, and intrauterine growth restriction.(1) In addition, ZIKV infection in other age groups has been associated with severe neurologic disease and the Guillain-Barré syndrome.(2) Transmission cycles between humans and Aedes aegypti mosquitoes in urban settings can cause large-scale epidemics of ZIKV infection. Although mosquitoes clearly are the primary cause of ZIKV outbreaks, . . . PMID:27433842

  4. Skin manifestations of West Nile virus infection.

    PubMed

    Del Giudice, P; Schuffenecker, I; Zeller, H; Grelier, M; Vandenbos, F; Dellamonica, P; Counillon, E

    2005-01-01

    West Nile virus (WNV) infection is a potentially lethal arbovirus infection. Many notable outbreaks have occurred during the last few years throughout the world, including Europe and the USA. The severity of the disease is mainly related to the neurological complications. A maculopapular exanthema is reported as a clinical sign of the disease. Recently an outbreak of WNV infection occurred in southern France. Three patients out of 6 had a similar skin roseola-like eruption. The cluster of 3 cases of similar febrile roseola of unexplained cause during the same week led to the diagnosis of the first WNV human outbreak in France for 40 years. PMID:16286745

  5. Immunopathogenesis Versus Protection in Dengue Virus Infections

    PubMed Central

    Rothman, Alan L.; Medin, Carey L.; Friberg, Heather; Currier, Jeffrey R.

    2014-01-01

    Dengue viruses (DENV) are mosquito-borne viruses that cause significant morbidity. The existence of four serotypes of DENV with partial immunologic cross-reactivity creates the opportunity for individuals to experience multiple acute DENV infections over the course of their lifetimes. Research over the past several years has revealed complex interactions between DENV and the human innate and adaptive immune systems that can have either beneficial or detrimental influences on the outcome of infection. Further studies that seek to distinguish protective from pathological immune responses in the context of natural DENV infection as well as clinical trials of candidate DENV vaccines have an important place in efforts to control the global impact of this re-emerging viral disease. PMID:24883262

  6. Immunopathogenesis Versus Protection in Dengue Virus Infections.

    PubMed

    Rothman, Alan L; Medin, Carey L; Friberg, Heather; Currier, Jeffrey R

    2014-03-01

    Dengue viruses (DENV) are mosquito-borne viruses that cause significant morbidity. The existence of four serotypes of DENV with partial immunologic cross-reactivity creates the opportunity for individuals to experience multiple acute DENV infections over the course of their lifetimes. Research over the past several years has revealed complex interactions between DENV and the human innate and adaptive immune systems that can have either beneficial or detrimental influences on the outcome of infection. Further studies that seek to distinguish protective from pathological immune responses in the context of natural DENV infection as well as clinical trials of candidate DENV vaccines have an important place in efforts to control the global impact of this re-emerging viral disease. PMID:24883262

  7. [Laboratory diagnosis of hepatitis C virus infection].

    PubMed

    Huber, K R; Kittl, E; Sebesta, C; Bauer, K

    2000-01-01

    In Austria, the prevalence of hepatitis C virus infections is 0.7% (17). Exclusion of a putative infection as well as diagnosis and continuous monitoring of HCV-disease produce considerable costs for the health system. How many and which patients with HCV infection will acquire life-threatening complications is by far not clear. Also, the causes for viral persistence and liver-complications remain obscure. For certain, complex interactions of viral and immunological mechanisms will determine the individual outcome of the disease (1). These considerations pose decisive demands on clinical diagnostics for HCV infections to be dealt with in detail: methods for qualitative detection of an infection as well as for analysis of subtypes and for quantitative determination of viral copies; monitoring of therapy; estimation of the progress of the disease and/or efficacy of therapy. PMID:11205177

  8. Cells in Dengue Virus Infection In Vivo

    PubMed Central

    Noisakran, Sansanee; Onlamoon, Nattawat; Songprakhon, Pucharee; Hsiao, Hui-Mien; Chokephaibulkit, Kulkanya; Perng, Guey Chuen

    2010-01-01

    Dengue has been recognized as one of the most important vector-borne emerging infectious diseases globally. Though dengue normally causes a self-limiting infection, some patients may develop a life-threatening illness, dengue hemorrhagic fever (DHF)/dengue shock syndrome (DSS). The reason why DHF/DSS occurs in certain individuals is unclear. Studies in the endemic regions suggest that the preexisting antibodies are a risk factor for DHF/DSS. Viremia and thrombocytopenia are the key clinical features of dengue virus infection in patients. The amounts of virus circulating in patients are highly correlated with severe dengue disease, DHF/DSS. Also, the disturbance, mainly a transient depression, of hematological cells is a critical clinical finding in acute dengue patients. However, the cells responsible for the dengue viremia are unresolved in spite of the intensive efforts been made. Dengue virus appears to replicate and proliferate in many adapted cell lines, but these in vitro properties are extremely difficult to be reproduced in primary cells or in vivo. This paper summarizes reports on the permissive cells in vitro and in vivo and suggests a hematological cell lineage for dengue virus infection in vivo, with the hope that a new focus will shed light on further understanding of the complexities of dengue disease. PMID:22331984

  9. Reaction of goats to infection with infectious bovine rhinotracheitis virus.

    PubMed

    Wafula, J S; Mushi, E Z; Wamwayi, H

    1985-07-01

    Intranasal exposure of goats to infectious bovine rhinotracheitis virus resulted in mild respiratory disease and virus reisolation from nasal secretions. No disease was produced in goats exposed to the same virus by the genital or ocular routes. There was serological evidence of contact transmission of infection from infected goats to cattle. Virus recrudescence was not detected in goats treated with dexamethasone two months after virus inoculation. PMID:2994191

  10. Virus infection, antiviral immunity, and autoimmunity

    PubMed Central

    Getts, Daniel R.; Chastain, Emily M. L.; Terry, Rachael L.; Miller, Stephen D.

    2014-01-01

    Summary As a group of disorders, autoimmunity ranks as the third most prevalent cause of morbidity and mortality in the Western World. However, the etiology of most autoimmune diseases remains unknown. Although genetic linkage studies support a critical underlying role for genetics, the geographic distribution of these disorders as well as the low concordance rates in monozygotic twins suggest that a combination of other factors including environmental ones are involved. Virus infection is a primary factor that has been implicated in the initiation of autoimmune disease. Infection triggers a robust and usually well-coordinated immune response that is critical for viral clearance. However, in some instances, immune regulatory mechanisms may falter, culminating in the breakdown of self-tolerance, resulting in immune-mediated attack directed against both viral and self-antigens. Traditionally, cross-reactive T-cell recognition, known as molecular mimicry, as well as bystander T-cell activation, culminating in epitope spreading, have been the predominant mechanisms elucidated through which infection may culminate in an T-cell-mediated autoimmune response. However, other hypotheses including virus-induced decoy of the immune system also warrant discussion in regard to their potential for triggering autoimmunity. In this review, we discuss the mechanisms by which virus infection and antiviral immunity contribute to the development of autoimmunity. PMID:23947356

  11. Psoralen inactivation of influenza and herpes simplex viruses and of virus-infected cells

    SciTech Connect

    Redfield, D.C.; Richman, D.D.; Oxman, M.N.; Kronenberg, L.H.

    1981-06-01

    Psoralen compounds covalently bind to nucleic acids when irradiated with long-wavelength ultraviolet light. This treatment can destroy the infectivity of deoxyribonucleic acid and ribonucleic acid viruses. Two psoralen compounds, 4'-hydroxymethyltrioxsalen and 4'-aminomethyltrioxsalen, were used with long-wavelength ultraviolet light to inactivate cell-free herpes simplex and influenza viruses and to render virus-infected cells noninfectious. This method of inactivation was compared with germicidal (short-wavelength) ultraviolet light irradiation. The antigenicity of the treated, virus-infected, antigen-bearing cells was examined by immunofluorescence and radioimmunoassay and by measuring the capacity of the herpes simplex virus-infected cells to stimulate virus-specific lymphocyte proliferation. The infectivity of the virus-infected cells could be totally eliminated without altering their viral antigenicity. The use of psoralen plus long-wavelength ultraviolet light is well suited to the preparation of noninfectious virus antigens and virus antigen-bearing cells for immunological assays.

  12. Human papilloma virus infection and psoriasis: Did human papilloma virus infection trigger psoriasis?

    PubMed Central

    Jain, Sonia P.; Gulhane, Sachin; Pandey, Neha; Bisne, Esha

    2015-01-01

    Psoriasis is an autoimmune chronic inflammatory skin disease known to be triggered by streptococcal and HIV infections. However, human papilloma virus infection (HPV) as a triggering factor for the development of psoriasis has not been reported yet. We, hereby report a case of plaque type with inverse psoriasis which probably could have been triggered by genital warts (HPV infection) and discuss the possible pathomechanisms for their coexistence and its management. PMID:26692619

  13. Phylogenetic analysis of the haemagglutinin gene of canine distemper virus strains detected from giant panda and raccoon dogs in China

    PubMed Central

    2013-01-01

    Background Canine distemper virus (CDV) infects a variety of carnivores, including wild and domestic Canidae. In this study, we sequenced and phylogenetic analyses of the hemagglutinin (H) genes from eight canine distemper virus (CDV) isolates obtained from seven raccoon dogs (Nyctereutes procyonoides) and a giant panda (Ailuropoda melanoleuca) in China. Results Phylogenetic analysis of the partial hemagglutinin gene sequences showed close clustering for geographic lineages, clearly distinct from vaccine strains and other wild-type foreign CDV strains, all the CDV strains were characterized as Asia-1 genotype and were highly similar to each other (91.5-99.8% nt and 94.4-99.8% aa). The giant panda and raccoon dogs all were 549Y on the HA protein in this study, irrespective of the host species. Conclusions These findings enhance our knowledge of the genetic characteristics of Chinese CDV isolates, and may facilitate the development of effective strategies for monitoring and controlling CDV for wild canids and non-cainds in China. PMID:23566727

  14. [A NEW PANDEMIC: ZIKA VIRUS INFECTION].

    PubMed

    Bourée, Patrice

    2016-06-01

    Zika virus is a flavivirus isolated in non human primates in 1647, then in humans 1954 (Uganda). It emerged on Micronesia (island af Yap) in 2007, then in French Polynesia in 2013-2014, in South America (mostly in Brazil and Colombia) in 2015 and in French West Indies in 2016. It is transmitted by the bite of Aedes mosquitoes. Zika virus infection is symptomatic in only 20% of cases and clinical presentation is associated with mild illness. But several neurological complications are reported (as Guillain-Barré syndrome: 48 cases in French Polynesia) and congenital malformations (microcephaly). Laboratory diagnosis is based on virus isolation by PCR. There is no specific treatment or vaccine available against the Zika virs. Prevention is based on measures of protection from mosquitoes bites. PMID:27538321

  15. Infection cycles of large DNA viruses: Emerging themes and underlying questions

    SciTech Connect

    Mutsafi, Yael Fridmann-Sirkis, Yael; Milrot, Elad; Hevroni, Liron; Minsky, Abraham

    2014-10-15

    The discovery of giant DNA viruses and the recent realization that such viruses are diverse and abundant blurred the distinction between viruses and cells. These findings elicited lively debates on the nature and origin of viruses as well as on their potential roles in the evolution of cells. The following essay is, however, concerned with new insights into fundamental structural and physical aspects of viral replication that were derived from studies conducted on large DNA viruses. Specifically, the entirely cytoplasmic replication cycles of Mimivirus and Vaccinia are discussed in light of the highly limited trafficking of large macromolecules in the crowded cytoplasm of cells. The extensive spatiotemporal order revealed by cytoplasmic viral factories is described and contended to play an important role in promoting the efficiency of these ‘nuclear-like’ organelles. Generation of single-layered internal membrane sheets in Mimivirus and Vaccinia, which proceeds through a novel membrane biogenesis mechanism that enables continuous supply of lipids, is highlighted as an intriguing case study of self-assembly. Mimivirus genome encapsidation was shown to occur through a portal different from the ‘stargate’ portal that is used for genome release. Such a ‘division of labor’ is proposed to enhance the efficacy of translocation processes of very large viral genomes. Finally, open questions concerning the infection cycles of giant viruses to which future studies are likely to provide novel and exciting answers are discussed. - Highlights: • The discovery of giant DNA viruses blurs the distinction between viruses and cells. • Mimivirus and Vaccinia replicate exclusively in their host cytoplasm. • Mimivirus genome is delivered through a unique portal coined the Stargate. • Generation of Mimivirus internal membrane proceeds through a novel pathway.

  16. Rabies virus infection of cultured rat sensory neurons.

    PubMed Central

    Lycke, E; Tsiang, H

    1987-01-01

    The axonal transport of rabies virus (challenge virus strain of fixed virus) was studied in differentiated rat embryonic dorsal root ganglion cells. In addition, we observed the attachment of rabies virus to neuronal extensions and virus production by infected neurons. A compartmentalized cell culture system was used, allowing infection and manipulation of neuronal extensions without exposing the neural soma to the virus. The cultures consisted of 60% large neuronal cells whose extensions exhibited neurofilament structures. Rabies virus demonstrated high binding affinity to unmyelinated neurites, as suggested by assays of virus adsorption and immunofluorescence studies. The rate of axoplasmic transport of virus was 12 to 24 mm/day, including the time required for internalization of the virus into neurites. The virus transport could be blocked by cytochalasin B, vinblastine, and colchicine, none of which negatively affected the production of virus in cells once the infection was established. It was concluded that, for the retrograde transfer of rabies virus by neurites from the periphery to the neuronal soma, the integrity of tubulin- and actin-containing structures is essential. The rat sensory neurons were characterized as permissive, moderately susceptible, but low producers of rabies virus. These neurons were capable of harboring rabies virus for long periods of time and able to release virus into the culture medium without showing any morphological alterations. The involvement of sensory neurons in rabies virus pathogenesis, both in viral transport and as a site for persistent viral infection, is discussed. Images PMID:2441076

  17. A single vertebrate DNA virus protein disarms invertebrate immunity to RNA virus infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Virus-host interactions drive a remarkable diversity of immune responses and countermeasures. While investigating virus-invertebrate host interactions we found that two RNA viruses with broad host ranges, vesicular stomatitis virus (VSV) and Sindbis virus (SINV), were unable to infect certain Lepido...

  18. Hepatitis B virus and hepatitis C virus dual infection

    PubMed Central

    Caccamo, Gaia; Saffioti, Francesca; Raimondo, Giovanni

    2014-01-01

    Hepatitis B virus (HBV) and hepatitis C virus (HCV) share common mode of transmission and both are able to induce a chronic infection. Dual HBV/HCV chronic coinfection is a fairly frequent occurrence, especially in high endemic areas and among individuals at high risk of parenterally transmitted infections. The intracellular interplay between HBV and HCV has not yet been sufficiently clarified, also due to the lack of a proper in vitro cellular model. Longitudinal evaluation of serum HBV DNA and HCV RNA amounts has revealed that complex virological profiles may be present in coinfected patients. Dual HBV/HCV infection has been associated to a severe course of the liver disease and to a high risk of developing hepatocellular carcinoma. Despite the clinical importance, solid evidence and clear guidelines for treatment of this special population are still lacking. This review summarizes the available data on the virological and clinical features as well as the therapeutic options of the dual HBV/HCV infection, and highlights the aspects that need to be better clarified. PMID:25356020

  19. Diagnostic challenges of hepatitis C virus infections.

    PubMed

    Huber, K; Sebesta, C; Worofka, B; Kittl, E; Hofmann, J; Klar, S; Hinterberger, W; Bauer, K

    1998-01-01

    In less than 10 years, tremendous progress has been made in our understanding of the biology of hepatitis C virus. Since it was defined as the causal agent of most hepatitis non-A, non-B infections in 1989, clinical laboratories now have access to powerful new techniques for the diagnosis of infection and control of therapy. Identification of the specific virus strain in the patients as well as measurement of the individual viral load and the prediction of a possible therapeutic success have become routine procedures. This effort is warranted because the treatment options are still limited, with alpha-interferon being the only approved drug. No new treatment regimens have emerged yet from the wealth of data from subtyping and quantitating. PMID:15094859

  20. Chaperones in hepatitis C virus infection

    PubMed Central

    Khachatoorian, Ronik; French, Samuel W

    2016-01-01

    The hepatitis C virus (HCV) infects approximately 3% of the world population or more than 185 million people worldwide. Each year, an estimated 350000-500000 deaths occur worldwide due to HCV-associated diseases including cirrhosis and hepatocellular carcinoma. HCV is the most common indication for liver transplantation in patients with cirrhosis worldwide. HCV is an enveloped RNA virus classified in the genus Hepacivirus in the Flaviviridae family. The HCV viral life cycle in a cell can be divided into six phases: (1) binding and internalization; (2) cytoplasmic release and uncoating; (3) viral polyprotein translation and processing; (4) RNA genome replication; (5) encapsidation (packaging) and assembly; and (6) virus morphogenesis (maturation) and secretion. Many host factors are involved in the HCV life cycle. Chaperones are an important group of host cytoprotective molecules that coordinate numerous cellular processes including protein folding, multimeric protein assembly, protein trafficking, and protein degradation. All phases of the viral life cycle require chaperone activity and the interaction of viral proteins with chaperones. This review will present our current knowledge and understanding of the role of chaperones in the HCV life cycle. Analysis of chaperones in HCV infection will provide further insights into viral/host interactions and potential therapeutic targets for both HCV and other viruses. PMID:26783419

  1. Mechanisms of Zika Virus Infection and Neuropathogenesis.

    PubMed

    Olagnier, David; Muscolini, Michela; Coyne, Carolyn B; Diamond, Michael S; Hiscott, John

    2016-08-01

    A spotlight has been focused on the mosquito-borne Zika virus (ZIKV) because of its epidemic outbreak in Brazil and Latin America, as well as the severe neurological manifestations of microcephaly and Guillain-Barré syndrome associated with infection. In this review, we discuss the recent literature on ZIKV-host interactions, including new mechanistic insight concerning the basis of ZIKV-induced neuropathogenesis. PMID:27348136

  2. Vaccinia virus infections in martial arts gym, Maryland, USA, 2008.

    PubMed

    Hughes, Christine M; Blythe, David; Li, Yu; Reddy, Ramani; Jordan, Carol; Edwards, Cindy; Adams, Celia; Conners, Holly; Rasa, Catherine; Wilby, Sue; Russell, Jamaal; Russo, Kelly S; Somsel, Patricia; Wiedbrauk, Danny L; Dougherty, Cindy; Allen, Christopher; Frace, Mike; Emerson, Ginny; Olson, Victoria A; Smith, Scott K; Braden, Zachary; Abel, Jason; Davidson, Whitni; Reynolds, Mary; Damon, Inger K

    2011-04-01

    Vaccinia virus is an orthopoxvirus used in the live vaccine against smallpox. Vaccinia virus infections can be transmissible and can cause severe complications in those with weakened immune systems. We report on a cluster of 4 cases of vaccinia virus infection in Maryland, USA, likely acquired at a martial arts gym. PMID:21470473

  3. Vaccination against bovine herpes mammillitis virus infections in guinea pigs.

    PubMed

    Smee, D F; Leonhardt, J A

    1994-01-01

    Bovine herpes mammillitis virus or bovine herpesvirus type 2 (BHV-2) causes ulcerative lesions on the teats and udders of infected cows. Since no commercial vaccine is available for this disease, we investigated certain experimental BHV-2 vaccines against this virus in infected guinea pigs. Vaginally infected guinea pigs get severe, self-limiting vaginal infections characterized by erythema and swelling and the production of measurable vaginal virus titers. Two vaccine approaches were investigated: vaccination with wild-type (WT) virus by the subcutaneous route, and vaccination either subcutaneously or intravaginally with a thymidine kinase (TK) deficient (TK-) virus. The TK- strain was prepared by passage of BHV-2 in the presence of the potent TK-dependent antiviral agent 1-(2'-deoxy-2'-fluoro-beta-D-arabinofuranosyl)-5-methyluracil (FMAU). The antiviral activity of FMAU against the virus in plaque reduction assays changed from 0.05 to 2 microM at the same time that the TK activity of the mutant virus decrease to 7% of WT virus TK activity. Subcutaneous vaccination of guinea pigs with WT and TK- viruses did not induce vaginal infection. Primary vaginal infection (vaccination) with the TK- virus led to greatly reduced lesion severity compared to vaginal infection with the WT virus. However, the amount of vaginal virus titers recovered during these primary infections was similar for both TK- and WT viruses, indicating that both viruses had equal infecting potential. Thirty days after vaccination the animals were re-infected intravaginally with WT virus. The vaccinated animals showed dramatically reduced lesion severity and low recoverable virus titers compared to age-matched nonvaccinated animals.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7928285

  4. Clinical and biological differences between recurrent herpes simplex virus and varicella-zoster virus infections

    SciTech Connect

    Straus, S.E. )

    1989-12-01

    The major features that distinguish recurrent herpes simplex virus infections from zoster are illustrated in this article by two case histories. The clinical and epidemiologic features that characterize recurrent herpes simplex virus and varicella-zoster virus infections are reviewed. It is noted that herpesvirus infections are more common and severe in patients with cellular immune deficiency. Each virus evokes both humoral and cellular immune response in the course of primary infection. DNA hybridization studies with RNA probes labelled with sulfur-35 indicate that herpes simplex viruses persist within neurons, and that varicella-zoster virus is found in the satellite cells that encircle the neurons.

  5. Vaccinia Virus Infection Requires Maturation of Macropinosomes.

    PubMed

    Rizopoulos, Zaira; Balistreri, Giuseppe; Kilcher, Samuel; Martin, Caroline K; Syedbasha, Mohammedyaseen; Helenius, Ari; Mercer, Jason

    2015-08-01

    The prototypic poxvirus, vaccinia virus (VACV), occurs in two infectious forms, mature virions (MVs) and extracellular virions (EVs). Both enter HeLa cells by inducing macropinocytic uptake. Using confocal microscopy, live-cell imaging, targeted RNAi screening and perturbants of endosome maturation, we analyzed the properties and maturation pathway of the macropinocytic vacuoles containing VACV MVs in HeLa cells. The vacuoles first acquired markers of early endosomes [Rab5, early endosome antigen 1 and phosphatidylinositol(3)P]. Prior to release of virus cores into the cytoplasm, they contained markers of late endosomes and lysosomes (Rab7a, lysosome-associated membrane protein 1 and sorting nexin 3). RNAi screening of endocytic cell factors emphasized the importance of late compartments for VACV infection. Follow-up perturbation analysis showed that infection required Rab7a and PIKfyve, confirming that VACV is a late-penetrating virus dependent on macropinosome maturation. VACV EV infection was inhibited by depletion of many of the same factors, indicating that both infectious particle forms share the need for late vacuolar conditions for penetration. PMID:25869659

  6. Chronic hepatitis B virus infection.

    PubMed

    McMahon, Brian J

    2014-01-01

    All providers, regardless of specialty, should perform screening for HBV on high-risk persons, especially those born in endemic countries. The primary care physician can perform the initial evaluation and follow-up of patients with chronic HBV by following the algorithm in this article and consulting with specialists when appropriate. Chronically infected patients should be followed on a regular basis, preferably every 6 months, with liver function tests, and when appropriate, HBV DNA levels. Those who meet the criteria for high risk for HCC should undergo liver ultrasound every 6 months. Powerful antiviral medications are available that can suppress but not cure HBV and result in resolution of liver inflammation and fibrosis, even cirrhosis, as well as decrease the risk of developing HCC. They should be used in those patients who meet the criteria outlined in the practice guidelines of the major liver societies. PMID:24266913

  7. Activity of andrographolide against chikungunya virus infection

    PubMed Central

    Wintachai, Phitchayapak; Kaur, Parveen; Lee, Regina Ching Hua; Ramphan, Suwipa; Kuadkitkan, Atichat; Wikan, Nitwara; Ubol, Sukathida; Roytrakul, Sittiruk; Chu, Justin Jang Hann; Smith, Duncan R.

    2015-01-01

    Chikungunya virus (CHIKV) is a re-emerging mosquito-borne alphavirus that has recently engendered large epidemics around the world. There is no specific antiviral for treatment of patients infected with CHIKV, and development of compounds with significant anti-CHIKV activity that can be further developed to a practical therapy is urgently required. Andrographolide is derived from Andrographis paniculata, a herb traditionally used to treat a number of conditions including infections. This study sought to determine the potential of andrographolide as an inhibitor of CHIKV infection. Andrographolide showed good inhibition of CHIKV infection and reduced virus production by approximately 3log10 with a 50% effective concentration (EC50) of 77 μM without cytotoxicity. Time-of-addition and RNA transfection studies showed that andrographolide affected CHIKV replication and the activity of andrographolide was shown to be cell type independent. This study suggests that andrographolide has the potential to be developed further as an anti-CHIKV therapeutic agent. PMID:26384169

  8. Activity of andrographolide against chikungunya virus infection.

    PubMed

    Wintachai, Phitchayapak; Kaur, Parveen; Lee, Regina Ching Hua; Ramphan, Suwipa; Kuadkitkan, Atichat; Wikan, Nitwara; Ubol, Sukathida; Roytrakul, Sittiruk; Chu, Justin Jang Hann; Smith, Duncan R

    2015-01-01

    Chikungunya virus (CHIKV) is a re-emerging mosquito-borne alphavirus that has recently engendered large epidemics around the world. There is no specific antiviral for treatment of patients infected with CHIKV, and development of compounds with significant anti-CHIKV activity that can be further developed to a practical therapy is urgently required. Andrographolide is derived from Andrographis paniculata, a herb traditionally used to treat a number of conditions including infections. This study sought to determine the potential of andrographolide as an inhibitor of CHIKV infection. Andrographolide showed good inhibition of CHIKV infection and reduced virus production by approximately 3log10 with a 50% effective concentration (EC50) of 77 μM without cytotoxicity. Time-of-addition and RNA transfection studies showed that andrographolide affected CHIKV replication and the activity of andrographolide was shown to be cell type independent. This study suggests that andrographolide has the potential to be developed further as an anti-CHIKV therapeutic agent. PMID:26384169

  9. High-Throughput Isolation of Giant Viruses in Liquid Medium Using Automated Flow Cytometry and Fluorescence Staining

    PubMed Central

    Khalil, Jacques Y. B.; Robert, Stephane; Reteno, Dorine G.; Andreani, Julien; Raoult, Didier; La Scola, Bernard

    2016-01-01

    The isolation of giant viruses using amoeba co-culture is tedious and fastidious. Recently, the procedure was successfully associated with a method that detects amoebal lysis on agar plates. However, the procedure remains time-consuming and is limited to protozoa growing on agar. We present here advances for the isolation of giant viruses. A high-throughput automated method based on flow cytometry and fluorescent staining was used to detect the presence of giant viruses in liquid medium. Development was carried out with the Acanthamoeba polyphaga strain widely used in past and current co-culture experiments. The proof of concept was validated with virus suspensions: artificially contaminated samples but also environmental samples from which viruses were previously isolated. After validating the technique, and fortuitously isolating a new Mimivirus, we automated the technique on 96-well plates and tested it on clinical and environmental samples using other protozoa. This allowed us to detect more than 10 strains of previously known species of giant viruses and seven new strains of a new virus lineage. This automated high-throughput method demonstrated significant time saving, and higher sensitivity than older techniques. It thus creates the means to isolate giant viruses at high speed. PMID:26858703

  10. High-Throughput Isolation of Giant Viruses in Liquid Medium Using Automated Flow Cytometry and Fluorescence Staining.

    PubMed

    Khalil, Jacques Y B; Robert, Stephane; Reteno, Dorine G; Andreani, Julien; Raoult, Didier; La Scola, Bernard

    2016-01-01

    The isolation of giant viruses using amoeba co-culture is tedious and fastidious. Recently, the procedure was successfully associated with a method that detects amoebal lysis on agar plates. However, the procedure remains time-consuming and is limited to protozoa growing on agar. We present here advances for the isolation of giant viruses. A high-throughput automated method based on flow cytometry and fluorescent staining was used to detect the presence of giant viruses in liquid medium. Development was carried out with the Acanthamoeba polyphaga strain widely used in past and current co-culture experiments. The proof of concept was validated with virus suspensions: artificially contaminated samples but also environmental samples from which viruses were previously isolated. After validating the technique, and fortuitously isolating a new Mimivirus, we automated the technique on 96-well plates and tested it on clinical and environmental samples using other protozoa. This allowed us to detect more than 10 strains of previously known species of giant viruses and seven new strains of a new virus lineage. This automated high-throughput method demonstrated significant time saving, and higher sensitivity than older techniques. It thus creates the means to isolate giant viruses at high speed. PMID:26858703

  11. KINETIC PROFILE OF INFLUENZA VIRUS INFECTION IN THREE RAT STRAINS

    EPA Science Inventory

    Abstract

    Influenza infection is a respiratory disease of viral origin that can cause major epidemics in man. The influenza virus infects and damages epithelial cells of the respiratory tract and causes pneumonia. Lung lesions of mice infected with influenza virus resembl...

  12. Respiratory Syncytial Virus Infection (RSV): Transmission and Prevention

    MedlinePlus

    ... CDC Cancel Submit Search The CDC Respiratory Syncytial Virus Infection (RSV) Note: Javascript is disabled or is ... school or childcare. They can then transmit the virus to other members of the family. RSV can ...

  13. Hepatitis B virus infection in immigrant populations

    PubMed Central

    Coppola, Nicola; Alessio, Loredana; Pisaturo, Mariantonietta; Macera, Margherita; Sagnelli, Caterina; Zampino, Rosa; Sagnelli, Evangelista

    2015-01-01

    Hepatitis B virus (HBV) is the most common cause of hepatitis worldwide, with nearly 350 million people chronically infected and 600000 deaths per year due to acute liver failure occurring during acute hepatitis or, more frequently, in HBV-related liver cirrhosis or hepatocellular carcinoma. Ongoing immigration from countries with a high HBV endemicity to those with a low HBV endemicity warrants particular attention to prevent the spread of HBV infection to the native population. This review article analyzes the epidemiology and virological and clinical characteristics of HBV infection in immigrant populations and in their host countries, and suggests prophylactic measures to prevent the spread of this infection. Among the immigrants from different geographical areas, those from South East Asia and sub-Saharan Africa show the highest prevalences of hepatitis B surface antigen (HBsAg) carriers, in accordance with the high endemicity of the countries of origin. The molecular characteristics of HBV infection in immigrants reflect those of the geographical areas of origin: HBV genotype A and D predominate in immigrants from Eastern Europe, B and C in those from Asia and genotype E in those from Africa. The literature data on the clinical course and treatment of HBsAg-positive immigrants are scanty. The management of HBV infection in immigrant populations is difficult and requires expert personnel and dedicated structures for their assistance. The social services, voluntary operators and cultural mediators are essential to achieve optimized psychological and clinical intervention. PMID:26730274

  14. Giant viruses and the origin of modern eukaryotes.

    PubMed

    Forterre, Patrick; Gaïa, Morgan

    2016-06-01

    Several authors have suggested that viruses from the NucleoCytoplasmic Large DNA Viruses group (NCLDV) have played an important role in the origin of modern eukaryotes. Notably, the viral eukaryogenesis theory posits that the nucleus originated from an ancient NCLDV-related virus. Focusing on the viral factory instead of the virion adds credit to this hypothesis, but also suggests alternative scenarios. Beside a role in the emergence of the nucleus, ancient NCLDV may have provided new genes and/or chromosomes to the proto-eukaryotic lineage. Phylogenetic analyses suggest that NCLDV informational proteins, related to those of Archaea and Eukarya, were either recruited by ancient NCLDV from proto-eukaryotes and/or transferred to proto-eukaryotes, in agreement with the antiquity of NCLDV and their possible role in eukaryogenesis. PMID:26894379

  15. African swine fever virus infection of the bushpig (Potamochoerus porcus) and its significance in the epidemiology of the disease.

    PubMed

    Anderson, E C; Hutchings, G H; Mukarati, N; Wilkinson, P J

    1998-04-30

    Warthog (Phacochoerus aethiopicus), giant forest hog (Hylochoerus meinertzhageni) and bushpig (Potamochoerus porcus) are known to be susceptible to infection with African swine fever (ASF) virus. Little however, is known about the ecology of the disease in the bushpig. This study has shown that the bushpig remains viraemic for between 35 and 91 days following infection during which time it is able to infect the tick vector O. moubata. These ticks were able to transmit the disease to pigs. The virus persists in the lymphatic tissues for less than 34 weeks. Bushpigs infected with LIL 20/l virus but not VIC T90/l virus transmitted infection to in-contact pigs. Infected domestic pigs did not transmit the infection to in-contact bushpigs. ASF virus was able to replicate in in vitro cultures of bushpig leucocytes and endothelial cells. Recovered bushpigs could be reinfected with some strains of virus but not others. While it has been demonstrated that bushpigs remain carriers of ASFV following infection a complete understanding of their significance in the epidemiology of the disease awaits further investigations of their association with O. moubata. PMID:9659687

  16. Acute Human Inkoo and Chatanga Virus Infections, Finland

    PubMed Central

    Kantele, Anu; Levanov, Lev; Kivistö, Ilkka; Brummer-Korvenkontio, Markus; Vaheri, Antti; Vapalahti, Olli

    2016-01-01

    Inkoo virus (INKV) and Chatanga virus (CHATV), which are circulating in Finland, are mosquitoborne California serogroup orthobunyaviruses that have a high seroprevalence among humans. Worldwide, INKV infection has been poorly described, and CHATV infection has been unknown. Using serum samples collected in Finland from 7,961 patients suspected of having viral neurologic disease or Puumala virus infection during the summers of 2001–2013, we analyzed the samples to detect California serogroup infections. IgM seropositivity revealed 17 acute infections, and cross-neutralization tests confirmed presence of INKV or CHATV infections. All children (<16 years of age) with INKV infection were hospitalized; adults were outpatients with mild disease, except for 1 who was hospitalized with CHATV infection. Symptoms included fever, influenza-like illness, nausea or vomiting, disorientation, nuchal rigidity, headache, drowsiness, and seizures. Although many INKV and CHATV infections appear to be subclinical, these viruses can cause more severe disease, especially in children. PMID:27088268

  17. Phosphatidylinositol inhibits respiratory syncytial virus infection

    PubMed Central

    Numata, Mari; Kandasamy, Pitchaimani; Nagashima, Yoji; Fickes, Rachel; Murphy, Robert C.; Voelker, Dennis R.

    2015-01-01

    Respiratory syncytial virus (RSV) infects nearly all children under age 2, and reinfection occurs throughout life, seriously impacting adults with chronic pulmonary diseases. Recent data demonstrate that the anionic pulmonary surfactant lipid phosphatidylglycerol (PG) exerts a potent antiviral effect against RSV in vitro and in vivo. Phosphatidylinositol (PI) is also an anionic pulmonary surfactant phospholipid, and we tested its antiviral activity. PI liposomes completely suppress interleukin-8 production from BEAS2B epithelial cells challenged with RSV. The presence of PI during viral challenge in vitro reduces infection by a factor of >103. PI binds RSV with high affinity, preventing virus attachment to epithelial cells. Intranasal inoculation with PI along with RSV in mice reduces the viral burden 30-fold, eliminates the influx of inflammatory cells, and reduces tissue histopathology. Pharmacological doses of PI persist for >6 h in mouse lung. Pretreatment of mice with PI at 2 h prior to viral infection effectively suppresses inflammation and reduces the viral burden by 85%. These data demonstrate that PI has potent antiviral properties, a long residence time in the extracellular bronchoalveolar compartment, and a significant prophylaxis window. The findings demonstrate PG and PI have complementary roles as intrinsic, innate immune antiviral mediators in the lung. PMID:25561461

  18. Vaccines for herpes simplex virus infections.

    PubMed

    Koelle, David M

    2006-02-01

    Infections with herpes simplex virus (HSV) type 1 (HSV-1) and type 2 (HSV-2) can have serious medical consequences. Although antiviral medications can suppress symptomatic disease, asymptomatic shedding and transmission, they neither cure nor alter the natural history of HSV infections. Manipulation of the immune response is one potential method to decrease disease burden. Current research on prophylactic and therapeutic vaccination approaches is discussed in this review, with a focus on compounds that have entered clinical trials or that display novel compositions or proposed mechanisms of action. One such vaccine is an alum and monophosphoryl lipid A-adjuvanted subunit glycoprotein D2 vaccine that has demonstrated activity in the prevention of HSV-2 infection and disease in HSV-uninfected women in a phase III clinical trial. Further confirmatory clinical trials of this vaccine are currently underway. Other vaccine formats also in development include attenuated live or replication-incompetent HSV-2 strains and technologies that target virus-specific CD8 T-cell responses. PMID:16499283

  19. Therapy and prophylaxis of Ebola virus infections.

    PubMed

    Feldmann, Heinz; Jones, Steven M; Schnittler, Hans-Joachim; Geisbert, Thomas

    2005-08-01

    The first cases of Ebola hemorrhagic fever were reported from Sudan and Zaire (now Democratic Republic of the Congo) in 1976, but the virus has only received significant attention since 1995. Until recently, the development of therapeutics or vaccines was not considered a priority. The knowledge gained during the past decade on the biology and pathogenesis of Ebola virus has led to the development of therapeutic strategies that are currently being investigated. Considering the aggressive nature of Ebola infections, in particular the rapid and overwhelming viral burdens, early diagnosis will play a significant role in determining the success of any intervention strategy. Advanced understanding of the immune response has produced several vaccine candidates of which a few can be considered for further evaluation. This review will summarize and discuss the current therapeutic and prophylactic strategies for Ebola hemorrhagic fever. PMID:16121689

  20. Schmallenberg virus experimental infection of sheep.

    PubMed

    Wernike, Kerstin; Hoffmann, Bernd; Bréard, Emmanuel; Bøtner, Anette; Ponsart, Claire; Zientara, Stéphan; Lohse, Louise; Pozzi, Nathalie; Viarouge, Cyril; Sarradin, Pierre; Leroux-Barc, Céline; Riou, Mickael; Laloy, Eve; Breithaupt, Angele; Beer, Martin

    2013-10-25

    Since late 2011, a novel orthobunyavirus, named Schmallenberg virus (SBV), has been implicated in many cases of severely malformed bovine and ovine offspring in Europe. In adult cattle, SBV is known to cause a mild transient disease; clinical signs include short febrile episodes, decreased milk production and diarrhoea for a few days. However, the knowledge about clinical signs and pathogenesis in adult sheep is limited. In the present study, adult sheep of European domestic breeds were inoculated with SBV either as cell culture grown virus or as virus with no history of passage in cell cultures. Various experimental set-ups were used. Sampling included blood collection at different time points during the experimental period and selected organ material at autopsy. Data from this study showed, that the RNAemic period in sheep was as short as reported for cattle; viral genome was detectable for about 3-5 days by real-time RT-PCR. In total, 13 out of 30 inoculated sheep became RNAemic, with the highest viral load in animals inoculated with virus from low cell culture passaged or the animal passaged material. Contact animals remained negative throughout the study. One RNAemic sheep showed diarrhoea for several days, but fever was not recorded in any of the animals. Antibodies were first detectable 10-14 days post inoculation. Viral RNA was detectable in spleen and lymph nodes up to day 44 post inoculation. In conclusion, as described for cattle, SBV-infection in adult sheep predominantly results in subclinical infection, transient RNAemia and a specific antibody response. Maintenance of viral RNA in the lymphoreticular system is observed for an extended period. PMID:23972950

  1. Bacterial Respiratory Infections Complicating Human Immunodeficiency Virus.

    PubMed

    Feldman, Charles; Anderson, Ronald

    2016-04-01

    Opportunistic bacterial and fungal infections of the lower respiratory tract, most commonly those caused by Streptococcus pneumoniae (the pneumococcus), Mycobacterium tuberculosis, and Pneumocystis jirovecii, remain the major causes of mortality in those infected with human immunodeficiency virus (HIV). Bacterial respiratory pathogens most prevalent in those infected with HIV, other than M. tuberculosis, represent the primary focus of the current review with particular emphasis on the pneumococcus, the leading cause of mortality due to HIV infection in the developed world. Additional themes include (1) risk factors; (2) the predisposing effects of HIV-mediated suppression on pulmonary host defenses, possibly intensified by smoking; (3) clinical and laboratory diagnosis, encompassing assessment of disease severity and outcome; and (4) antibiotic therapy. The final section addresses current recommendations with respect to pneumococcal immunization in the context of HIV infection, including an overview of the rationale underpinning the current "prime-boost" immunization strategy based on sequential administration of pneumococcal conjugate vaccine 13 and pneumococcal polysaccharide vaccine 23. PMID:26974299

  2. Amoebae as battlefields for bacteria, giant viruses, and virophages.

    PubMed

    Slimani, Meriem; Pagnier, Isabelle; Raoult, Didier; La Scola, Bernard

    2013-04-01

    When amoebae are simultaneously infected with Acanthamoeba polyphaga Mimivirus (APM) and the strictly intracellular BABL1 bacterium, the latter is always lost after serial subculturing. We showed that the virophage Sputnik 1, by reducing APM fitness, preserved BABL1 growth in acute and chronic models. This capability of a virophage to modulate the virulence of mimiviruses highlights the competition that occurs between them during natural host infection. PMID:23388714

  3. Hepatitis B virus infection in Indonesia

    PubMed Central

    Yano, Yoshihiko; Utsumi, Takako; Lusida, Maria Inge; Hayashi, Yoshitake

    2015-01-01

    Approximately 240 million people are chronically infected with hepatitis B virus (HBV), 75% of whom reside in Asia. Approximately 600000 of infected patients die each year due to HBV-related diseases or hepatocellular carcinoma (HCC). The endemicity of hepatitis surface antigen in Indonesia is intermediate to high with a geographical difference. The risk of HBV infection is high in hemodialysis (HD) patients, men having sex with men, and health care workers. Occult HBV infection has been detected in various groups such as blood donors, HD patients, and HIV-infected individuals and children. The most common HBV subgenotype in Indonesia is B3 followed by C1. Various novel subgenotypes of HBV have been identified throughout Indonesia, with the novel HBV subgenotypes C6-C16 and D6 being successfully isolated. Although a number of HBV subgenotypes have been discovered in Indonesia, genotype-related pathogenicity has not yet been elucidated in detail. Therefore, genotype-related differences in the prognosis of liver disease and their effects on treatments need to be determined. A previous study conducted in Indonesia revealed that hepatic steatosis was associated with disease progression. Pre-S2 mutations and mutations at C1638T and T1753V in HBV/B3 have been associated with advanced liver diseases including HCC. However, drug resistance to lamivudine, which is prominent in Indonesia, remains obscure. Although the number of studies on HBV in Indonesia has been increasing, adequate databases on HBV infection are limited. We herein provided an overview of the epidemiology and clinical characteristics of HBV infection in Indonesia. PMID:26478663

  4. Respiratory syncytial virus infection in elderly adults.

    PubMed

    Falsey, Ann R; Walsh, Edward E

    2005-01-01

    Respiratory syncytial virus (RSV) infection is now recognised as a significant problem in elderly adults. Epidemiological evidence indicates the impact of RSV in older adults may be similar to non-pandemic influenza, both in the community and in long-term care facilities. Attack rates in nursing homes are approximately 5-10% per year with significant rates of pneumonia (10-20%) and death (2-5%). Estimates using US health care databases and viral surveillance results over a 9-year period indicate that RSV infection causes approximately 10,000 all-cause deaths annually among persons >64 years of age. In contrast, influenza A accounted for approximately 37,000 yearly deaths in the same age group. The clinical features of RSV infection may be difficult to distinguish from those of influenza but include nasal congestion, cough, wheezing and low-grade fever. Older persons with underlying heart and lung disease and immunocompromised patients are at highest risk for RSV infection-related pneumonia and death. Diagnosis of RSV infection in adults is difficult because viral culture and antigen detection are insensitive, presumably because of low viral titres. The combination of serology and reverse transcriptase polymerase chain reaction assay offers the best sensitivity and specificity for the diagnosis of RSV but unfortunately these techniques are not widely available; consequently, most adult RSV disease goes unrecognised. Although treatment of RSV infection in the elderly is largely supportive, early therapy with ribavirin and intravenous gamma-globulin improves survival in immunocompromised persons. An effective RSV vaccine has not yet been developed. Therefore, prevention of RSV is limited to standard infection control practices, such as hand washing and the use of gowns and gloves. PMID:16038573

  5. Dynamics of perinatal bovine leukemia virus infection

    PubMed Central

    2014-01-01

    Background Bovine leukemia virus (BLV) is highly endemic in many countries, including Argentina. As prevention of the spread from infected animals is of primary importance in breaking the cycle of BLV transmission, it is important to know the pathophysiology of BLV infection in young animals, as they are the main source of animal movement. In this work, we determined the proviral load and antibody titers of infected newborn calves from birth to first parturition (36 months). Results All calves under study were born to infected dams with high proviral load (PVL) in blood and high antibody titers and detectable provirus in the colostrum. The PVL for five out of seven calves was low at birth. All animals reached PVLs of more than 1% infected peripheral blood mononuclear cells (PBMCs), three at 3 months, one at 6 months, and one at 12 months. High PVLs persisted until the end of the study, and, in two animals, exceeded one BLV copy per cell. Two other calves maintained a high PVL from birth until the end of the study. Antibody titers were 32 or higher in the first sample from six out of seven calves. These decayed at 3–6 months to 16 or lower, and then increased again after this point. Conclusions Calves infected during the first week of life could play an active role in early propagation of BLV to susceptible animals, since their PVL raised up during the first 12 months and persist as high for years. Early elimination could help to prevent transmission to young susceptible animals and to their own offspring. To our knowledge, this is the first study of the kinetics of BLV proviral load and antibody titers in newborn infected calves. PMID:24708791

  6. Zika Virus Infects Human Placental Macrophages.

    PubMed

    Quicke, Kendra M; Bowen, James R; Johnson, Erica L; McDonald, Circe E; Ma, Huailiang; O'Neal, Justin T; Rajakumar, Augustine; Wrammert, Jens; Rimawi, Bassam H; Pulendran, Bali; Schinazi, Raymond F; Chakraborty, Rana; Suthar, Mehul S

    2016-07-13

    The recent Zika virus (ZIKV) outbreak in Brazil has been directly linked to increased cases of microcephaly in newborns. Current evidence indicates that ZIKV is transmitted vertically from mother to fetus. However, the mechanism of intrauterine transmission and the cell types involved remain unknown. We demonstrate that the contemporary ZIKV strain PRVABC59 (PR 2015) infects and replicates in primary human placental macrophages, called Hofbauer cells, and to a lesser extent in cytotrophoblasts, isolated from villous tissue of full-term placentae. Viral replication coincides with induction of type I interferon (IFN), pro-inflammatory cytokines, and antiviral gene expression, but with minimal cell death. Our results suggest a mechanism for intrauterine transmission in which ZIKV gains access to the fetal compartment by directly infecting placental cells and disrupting the placental barrier. PMID:27247001

  7. MG-Digger: An Automated Pipeline to Search for Giant Virus-Related Sequences in Metagenomes.

    PubMed

    Verneau, Jonathan; Levasseur, Anthony; Raoult, Didier; La Scola, Bernard; Colson, Philippe

    2016-01-01

    The number of metagenomic studies conducted each year is growing dramatically. Storage and analysis of such big data is difficult and time-consuming. Interestingly, analysis shows that environmental and human metagenomes include a significant amount of non-annotated sequences, representing a 'dark matter.' We established a bioinformatics pipeline that automatically detects metagenome reads matching query sequences from a given set and applied this tool to the detection of sequences matching large and giant DNA viral members of the proposed order Megavirales or virophages. A total of 1,045 environmental and human metagenomes (≈ 1 Terabase) were collected, processed, and stored on our bioinformatics server. In addition, nucleotide and protein sequences from 93 Megavirales representatives, including 19 giant viruses of amoeba, and 5 virophages, were collected. The pipeline was generated by scripts written in Python language and entitled MG-Digger. Metagenomes previously found to contain megavirus-like sequences were tested as controls. MG-Digger was able to annotate 100s of metagenome sequences as best matching those of giant viruses. These sequences were most often found to be similar to phycodnavirus or mimivirus sequences, but included reads related to recently available pandoraviruses, Pithovirus sibericum, and faustoviruses. Compared to other tools, MG-Digger combined stand-alone use on Linux or Windows operating systems through a user-friendly interface, implementation of ready-to-use customized metagenome databases and query sequence databases, adjustable parameters for BLAST searches, and creation of output files containing selected reads with best match identification. Compared to Metavir 2, a reference tool in viral metagenome analysis, MG-Digger detected 8% more true positive Megavirales-related reads in a control metagenome. The present work shows that massive, automated and recurrent analyses of metagenomes are effective in improving knowledge about the

  8. MG-Digger: An Automated Pipeline to Search for Giant Virus-Related Sequences in Metagenomes

    PubMed Central

    Verneau, Jonathan; Levasseur, Anthony; Raoult, Didier; La Scola, Bernard; Colson, Philippe

    2016-01-01

    The number of metagenomic studies conducted each year is growing dramatically. Storage and analysis of such big data is difficult and time-consuming. Interestingly, analysis shows that environmental and human metagenomes include a significant amount of non-annotated sequences, representing a ‘dark matter.’ We established a bioinformatics pipeline that automatically detects metagenome reads matching query sequences from a given set and applied this tool to the detection of sequences matching large and giant DNA viral members of the proposed order Megavirales or virophages. A total of 1,045 environmental and human metagenomes (≈ 1 Terabase) were collected, processed, and stored on our bioinformatics server. In addition, nucleotide and protein sequences from 93 Megavirales representatives, including 19 giant viruses of amoeba, and 5 virophages, were collected. The pipeline was generated by scripts written in Python language and entitled MG-Digger. Metagenomes previously found to contain megavirus-like sequences were tested as controls. MG-Digger was able to annotate 100s of metagenome sequences as best matching those of giant viruses. These sequences were most often found to be similar to phycodnavirus or mimivirus sequences, but included reads related to recently available pandoraviruses, Pithovirus sibericum, and faustoviruses. Compared to other tools, MG-Digger combined stand-alone use on Linux or Windows operating systems through a user-friendly interface, implementation of ready-to-use customized metagenome databases and query sequence databases, adjustable parameters for BLAST searches, and creation of output files containing selected reads with best match identification. Compared to Metavir 2, a reference tool in viral metagenome analysis, MG-Digger detected 8% more true positive Megavirales-related reads in a control metagenome. The present work shows that massive, automated and recurrent analyses of metagenomes are effective in improving knowledge about

  9. First Isolation of a Giant Virus from Wild Hirudo medicinalis Leech: Mimiviridae isolation in Hirudo medicinalis

    PubMed Central

    Boughalmi, Mondher; Pagnier, Isabelle; Aherfi, Sarah; Colson, Philippe; Raoult, Didier; La Scola, Bernard

    2013-01-01

    Giant viruses and amoebae are common in freshwater, where they can coexist with other living multicellular organisms. We screened leeches from the species Hirudo medicinalis for giant viruses. We analyzed five H. medicinalis obtained from Tunisia (3) and France (2). The leeches were decontaminated and then dissected to remove internal parts for co-culture with Acanthamoeba polyphaga. The genomes of isolated viruses were sequenced on a 454 Roche instrument, and a comparative genomics analysis was performed. One Mimivirus was isolated and the strain was named Hirudovirus. The genome assembly generated two scaffolds, which were 1,155,382 and 25,660 base pairs in length. Functional annotations were identified for 47% of the genes, which corresponds to 466 proteins. The presence of Mimividae in the same ecological niche as wild Hirudo may explain the presence of the mimivirus in the digestive tract of the leech, and several studies have already shown that viruses can persist in the digestive tracts of leeches fed contaminated blood. As leeches can be used medically and Mimiviruses have the potential to be an infectious agent in humans, patients treated with leeches should be surveyed to investigate a possible connection. PMID:24287596

  10. Honey Bee Infecting Lake Sinai Viruses

    PubMed Central

    Daughenbaugh, Katie F.; Martin, Madison; Brutscher, Laura M.; Cavigli, Ian; Garcia, Emma; Lavin, Matt; Flenniken, Michelle L.

    2015-01-01

    Honey bees are critical pollinators of important agricultural crops. Recently, high annual losses of honey bee colonies have prompted further investigation of honey bee infecting viruses. To better characterize the recently discovered and very prevalent Lake Sinai virus (LSV) group, we sequenced currently circulating LSVs, performed phylogenetic analysis, and obtained images of LSV2. Sequence analysis resulted in extension of the LSV1 and LSV2 genomes, the first detection of LSV4 in the US, and the discovery of LSV6 and LSV7. We detected LSV1 and LSV2 in the Varroa destructor mite, and determined that a large proportion of LSV2 is found in the honey bee gut, suggesting that vector-mediated, food-associated, and/or fecal-oral routes may be important for LSV dissemination. Pathogen-specific quantitative PCR data, obtained from samples collected during a small-scale monitoring project, revealed that LSV2, LSV1, Black queen cell virus (BQCV), and Nosema ceranae were more abundant in weak colonies than strong colonies within this sample cohort. Together, these results enhance our current understanding of LSVs and illustrate the importance of future studies aimed at investigating the role of LSVs and other pathogens on honey bee health at both the individual and colony levels. PMID:26110586

  11. Honey Bee Infecting Lake Sinai Viruses.

    PubMed

    Daughenbaugh, Katie F; Martin, Madison; Brutscher, Laura M; Cavigli, Ian; Garcia, Emma; Lavin, Matt; Flenniken, Michelle L

    2015-06-01

    Honey bees are critical pollinators of important agricultural crops. Recently, high annual losses of honey bee colonies have prompted further investigation of honey bee infecting viruses. To better characterize the recently discovered and very prevalent Lake Sinai virus (LSV) group, we sequenced currently circulating LSVs, performed phylogenetic analysis, and obtained images of LSV2. Sequence analysis resulted in extension of the LSV1 and LSV2 genomes, the first detection of LSV4 in the US, and the discovery of LSV6 and LSV7. We detected LSV1 and LSV2 in the Varroa destructor mite, and determined that a large proportion of LSV2 is found in the honey bee gut, suggesting that vector-mediated, food-associated, and/or fecal-oral routes may be important for LSV dissemination. Pathogen-specific quantitative PCR data, obtained from samples collected during a small-scale monitoring project, revealed that LSV2, LSV1, Black queen cell virus (BQCV), and Nosema ceranae were more abundant in weak colonies than strong colonies within this sample cohort. Together, these results enhance our current understanding of LSVs and illustrate the importance of future studies aimed at investigating the role of LSVs and other pathogens on honey bee health at both the individual and colony levels. PMID:26110586

  12. Oral manifestations of hepatitis C virus infection

    PubMed Central

    Carrozzo, Marco; Scally, Kara

    2014-01-01

    Extrahepatic manifestations (EHMs) of hepatitis C virus (HCV) infection can affect a variety of organ systems with significant morbidity and mortality. Some of the most frequently reported EHM of HCV infection, involve the oral region predominantly or exclusively. Oral lichen planus (OLP) is a chronic inflammatory condition that is potentially malignant and represents cell-mediated reaction to a variety of extrinsic antigens, altered self-antigens, or super antigens. Robust epidemiological evidence support the link between OLP and HCV. As the virus may replicate in the oral mucosa and attract HCV-specific T lymphocytes, HCV may be implicated in OLP pathogenesis. Sjögren syndrome (SjS) is an autoimmune exocrinopathy, characterized by dryness of the mouth and eyes and a multitude of other systemic signs and symptoms. SjS patients have also an increased risk of non-Hodgkin lymphoma. Patients with chronic hepatitis C do frequently have histological signs of Sjögren-like sialadenitis with mild or even absent clinical symptoms. However, it is still unclear if HCV may cause a disease mimicking SjS or it is directly responsible for the development of SjS in a specific subset of patients. Oral squamous cell carcinoma is the most common oral malignant tumour and at least in some part of the world could be linked to HCV. PMID:24976694

  13. Encephalomyocarditis virus infections in an Australian zoo.

    PubMed

    Reddacliff, L A; Kirkland, P D; Hartley, W J; Reece, R L

    1997-06-01

    Fatal encephalomyocarditis virus (EMCV) infections in a ring-tailed lemur (Lemur catta), a squirrel monkey (Saimiri sciureus), three mandrills (Mandrillus sphinx), a chimpanzee (Pan troglodytes), a pygmy hippopotamus (Choeropsis liberiensis), and two Goodfellows tree kangaroos (Dendrolagus goodfellowi) occurred at Taronga Zoo. This is the first description of EMCV in a zoological collection outside of the United States. Regardless of species, the most common clinical presentation was sudden death. The gross pathologic changes were diffuse or focal pallor of the myocardium with occasional marked pulmonary congestion. Necrotizing nonsuppurative myocarditis was consistently present. EMCV was isolated from only one of 54 feral rodents examined. No antibodies to EMCV were detected with a serum neutralization test in 79 stored sera from a wide variety of zoo mammals. Titers of 1:16, 1:16, and 1:4 were recorded for a spider monkey (Aeteles geoffroyi), a lion (Panthera leo), and an orangutan (Pongo pygmaeus), respectively. Of seven mandrills tested in 1988, six had measurable virus titers. Later testing indicated that these titers did not persist, and one mandrill with a titer > 1:128 in 1988 subsequently succumbed to EMCV infection in 1991. PMID:9279403

  14. Treatment with Doxycycline of Generalized Annular Elastolytic Giant Cell Granuloma Associated with Borrelia burgdorferi Infection

    PubMed Central

    Tas, B; Caglar, A; Ozdemir, B

    2015-01-01

    ABSTRACT This is a case of generalized annular elastolytic giant cell granuloma (AEGCG) associated with borrelia infection and genes of p-30, p-31, p-39. A possible cross-mediated reaction from the T-cell type which might have induced the AEGCG is discussed from the concept of “heat-shock proteins (HSPs) and molecular mimicry”. PMID:26624605

  15. Rabies virus infects mouse and human lymphocytes and induces apoptosis.

    PubMed Central

    Thoulouze, M I; Lafage, M; Montano-Hirose, J A; Lafon, M

    1997-01-01

    Attenuated and highly neurovirulent rabies virus strains have distinct cellular tropisms. Highly neurovirulent strains such as the challenge virus standard (CVS) are highly neurotropic, whereas the attenuated strain ERA also infects nonneuronal cells. We report that both rabies virus strains infect activated murine lymphocytes and the human lymphoblastoid Jurkat T-cell line in vitro. The lymphocytes are more permissive to the attenuated ERA rabies virus strain than to the CVS strain in both cases. We also report that in contrast to that of the CVS strain, ERA viral replication induces apoptosis of infected Jurkat T cells, and cell death is concomitant with viral glycoprotein expression, suggesting that this protein has a role in the induction of apoptosis. Our data indicate that (i) rabies virus infects lymphocytes, (ii) lymphocyte infection with the attenuated rabies virus strain causes apoptosis, and (iii) apoptosis does not hinder rabies virus production. In contrast to CVS, ERA rabies virus and other attenuated rabies virus vaccines stimulate a strong immune response and are efficient live vaccines. The paradoxical finding that a rabies virus triggers a strong immune response despite the fact that it infects lymphocytes and induces apoptosis is discussed in terms of the function of apoptosis in the immune response. PMID:9311815

  16. Simultaneous multiplex PCR detection of seven cucurbit-infecting viruses.

    PubMed

    Kwon, Ji Yeon; Hong, Jin Sung; Kim, Min Jea; Choi, Sun Hee; Min, Byeong Eun; Song, Eun Gyeong; Kim, Hyun Hee; Ryu, Ki Hyun

    2014-09-01

    Two multiplex polymerase chain reaction (PCR) systems using dual priming oligonucleotide (DPO) primers were developed for the simultaneous detection of seven cucurbit-infecting viruses. One system allows for the detection of papaya ringspot virus, watermelon mosaic virus, and zucchini yellow mosaic virus, whereas the other permits the detection of cucumber green mottle mosaic virus, cucumber fruit mottle mosaic virus, kyuri green mottle mosaic virus, and zucchini green mottle mosaic virus. Viral species-specific DPO primers developed in this study detected as little as 10 fg/μl of viral RNA under monoplex conditions and 10 pg/μl of viral RNA under multiplex conditions. Multiplex PCR using the DPO primer sets was capable of amplifying viral genes at annealing temperatures ranging from 53 °C to 63 °C. Whereas the use of conventional primers gave rise to non-specific bands, the DPO primers detected target viral genes in the absence of non-specific amplification. When these DPO multiplex primer sets were applied to virus-infected cucurbit samples obtained in the field, multiple infection as well as single infection was accurately identified. This novel approach could also detect multiple viruses in infected seeds. The reliability of multiplex PCR systems using DPO primers for plant virus detection is discussed. PMID:24937806

  17. Human Muscle Satellite Cells as Targets of Chikungunya Virus Infection

    PubMed Central

    Ozden, Simona; Huerre, Michel; Riviere, Jean-Pierre; Coffey, Lark L.; Afonso, Philippe V.; Mouly, Vincent; de Monredon, Jean; Roger, Jean-Christophe; El Amrani, Mohamed; Yvin, Jean-Luc; Jaffar, Marie-Christine; Frenkiel, Marie-Pascale; Sourisseau, Marion; Schwartz, Olivier; Butler-Browne, Gillian; Desprès, Philippe; Gessain, Antoine; Ceccaldi, Pierre-Emmanuel

    2007-01-01

    Background Chikungunya (CHIK) virus is a mosquito-transmitted alphavirus that causes in humans an acute infection characterised by fever, polyarthralgia, head-ache, and myalgia. Since 2005, the emergence of CHIK virus was associated with an unprecedented magnitude outbreak of CHIK disease in the Indian Ocean. Clinically, this outbreak was characterized by invalidating poly-arthralgia, with myalgia being reported in 97.7% of cases. Since the cellular targets of CHIK virus in humans are unknown, we studied the pathogenic events and targets of CHIK infection in skeletal muscle. Methodology/Principal Findings Immunohistology on muscle biopsies from two CHIK virus-infected patients with myositic syndrome showed that viral antigens were found exclusively inside skeletal muscle progenitor cells (designed as satelllite cells), and not in muscle fibers. To evaluate the ability of CHIK virus to replicate in human satellite cells, we assessed virus infection on primary human muscle cells; viral growth was observed in CHIK virus-infected satellite cells with a cytopathic effect, whereas myotubes were essentially refractory to infection. Conclusions/Significance This report provides new insights into CHIK virus pathogenesis, since it is the first to identify a cellular target of CHIK virus in humans and to report a selective infection of muscle satellite cells by a viral agent in humans. PMID:17565380

  18. Pathogenesis and pathobiology of avian influenza virus infection in birds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian Influenza (AI) viruses vary in their ability to produce infection, disease and death in different bird species. Based on the pathobiological features in chickens, AI viruses are categorized as, low (LP) and high pathogenicity (HP). Typically, LPAI (low pathogenicity avian influenza) viruses ...

  19. Pathobiology of avian influenza virus infections in wild birds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Individual avian Influenza (AI) viruses vary in their ability to produce infection, disease and death in different bird species. Based on the pathobiological features in chickens, AI viruses (AIV) are categorized as low pathogenicity (LPAI) or high pathogenicity (HPAI) viruses, and can be of any of...

  20. Comparative pathology of select agent influenza A virus infections

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Influenza A virus infections may spread rapidly in human populations and cause acute respiratory disease with variable mortality. Two of these influenza viruses have been designated as select agents because of the high case fatality rate: 1918 H1N1 virus and highly pathogenic avian influenza (HPAI) ...

  1. Zika Virus Infection Acquired During Brief Travel to Indonesia

    PubMed Central

    Kwong, Jason C.; Druce, Julian D.; Leder, Karin

    2013-01-01

    Zika virus infection closely resembles dengue fever. It is possible that many cases are misdiagnosed or missed. We report a case of Zika virus infection in an Australian traveler who returned from Indonesia with fever and rash. Further case identification is required to determine the evolving epidemiology of this disease. PMID:23878182

  2. If You Have Chronic Hepatitis B Virus (HBV) Infection

    MedlinePlus

    If you have chronic hepatitis B virus (HBV) infection . . . If you have chronic hepatitis B virus (HBV) infection, you are not alone. Today, approximately one ... receive pneumococcal polysaccharide vac- cine.  Get vaccinated against hepatitis A. Hepati- tis A can further damage your ...

  3. First Imported Case of Zika Virus Infection into Korea.

    PubMed

    Jang, Hee-Chang; Park, Wan Beom; Kim, Uh Jin; Chun, June Young; Choi, Su-Jin; Choe, Pyoeng Gyun; Jung, Sook-In; Jee, Youngmee; Kim, Nam-Joong; Choi, Eun Hwa; Oh, Myoung-Don

    2016-07-01

    Since Zika virus has been spreading rapidly in the Americas from 2015, the outbreak of Zika virus infection becomes a global health emergency because it can cause neurological complications and adverse fetal outcome including microcephaly. Here, we report clinical manifestations and virus isolation findings from a case of Zika virus infection imported from Brazil. The patient, 43-year-old Korean man, developed fever, myalgia, eyeball pain, and maculopapular rash, but not neurological manifestations. Zika virus was isolated from his semen, and reverse-transcriptase PCR was positive for the virus in the blood, urine, and saliva on the 7th day of the illness but was negative on the 21st day. He recovered spontaneously without any neurological complications. He is the first case of Zika virus infection in Korea imported from Brazil. PMID:27366020

  4. First Imported Case of Zika Virus Infection into Korea

    PubMed Central

    Jee, Youngmee

    2016-01-01

    Since Zika virus has been spreading rapidly in the Americas from 2015, the outbreak of Zika virus infection becomes a global health emergency because it can cause neurological complications and adverse fetal outcome including microcephaly. Here, we report clinical manifestations and virus isolation findings from a case of Zika virus infection imported from Brazil. The patient, 43-year-old Korean man, developed fever, myalgia, eyeball pain, and maculopapular rash, but not neurological manifestations. Zika virus was isolated from his semen, and reverse-transcriptase PCR was positive for the virus in the blood, urine, and saliva on the 7th day of the illness but was negative on the 21st day. He recovered spontaneously without any neurological complications. He is the first case of Zika virus infection in Korea imported from Brazil. PMID:27366020

  5. Agglutination of Sindbis Virus and of Cells Infected with Sindbis Virus by Plant Lectins

    PubMed Central

    Birdwell, Charles R.; Strauss, James H.

    1973-01-01

    We have examined the agglutination of Sindbis virus and of chick and hamster cells infected with Sindbis virus by two of the plant lectins, concanavalin A and Ricinus communis agglutinin. Both lectins agglutinate the virus by binding to the polysaccharide chains of the envelope glycoproteins. Both chick and hamster cells exhibit increased agglutination by the lectins after infection by Sindbis virus. In the case of chick cells infected with Sindbis virus, this increase in agglutinability occurs between 3 and 5 h after infection. Infected and mock-infected cells bind the same amount of 3H-labeled concanavalin A, which suggests that the increase in agglutination after infection is due to rearrangements at the cell surface rather than to insertion of new lectin binding sites per se. PMID:4735591

  6. Identification of a Role for Nucleolin in Rabies Virus Infection

    PubMed Central

    Oksayan, S.; Nikolic, J.; David, C. T.; Blondel, D.; Jans, D. A.

    2014-01-01

    Rabies virus replicates in the cytoplasm of host cells, but rabies virus phosphoprotein (P-protein) undergoes active nucleocytoplasmic trafficking. Here we show that the largely nuclear P-protein isoform P3 can localize to nucleoli and forms specific interactions with nucleolin. Importantly, depletion of nucleolin expression inhibits viral protein expression and infectious virus production by infected cells. This provides the first evidence that lyssaviruses interact with nucleolin and that nucleolin is important to lyssavirus infection. PMID:25428867

  7. Identification of a role for nucleolin in rabies virus infection.

    PubMed

    Oksayan, S; Nikolic, J; David, C T; Blondel, D; Jans, D A; Moseley, G W

    2015-02-01

    Rabies virus replicates in the cytoplasm of host cells, but rabies virus phosphoprotein (P-protein) undergoes active nucleocytoplasmic trafficking. Here we show that the largely nuclear P-protein isoform P3 can localize to nucleoli and forms specific interactions with nucleolin. Importantly, depletion of nucleolin expression inhibits viral protein expression and infectious virus production by infected cells. This provides the first evidence that lyssaviruses interact with nucleolin and that nucleolin is important to lyssavirus infection. PMID:25428867

  8. Pathogenesis of Hendra and Nipah virus infection in humans.

    PubMed

    Escaffre, Olivier; Borisevich, Viktoriya; Rockx, Barry

    2013-04-01

    Hendra virus (HeV) and Nipah virus (NiV) are emerging zoonotic viruses that cause severe and often lethal respiratory illness and encephalitis in humans. Henipaviruses can infect a wide range of species and human-to-human transmission has been observed for NiV. While the exact route of transmission in humans is not known, experimental infection in different animal species suggests that infection can be efficiently initiated after respiratory challenge. The limited data on histopathological changes in fatal human cases of HeV and NiV suggest that endothelial cells are an important target during the terminal stage of infection; however, it is unknown where these viruses initially establish infection and how the virus disseminates from the respiratory tract to the central nervous system and other organs. Here we review the current concepts in henipavirus pathogenesis in humans. PMID:23592639

  9. Prevalence of occult hepatitis C virus infection in the Iranian patients with human immunodeficiency virus infection.

    PubMed

    Bokharaei-Salim, Farah; Keyvani, Hossein; Esghaei, Maryam; Zare-Karizi, Shohreh; Dermenaki-Farahani, Sahar-Sadat; Hesami-Zadeh, Khashayar; Fakhim, Shahin

    2016-11-01

    Occult hepatitis C virus (HCV) infection is a new form of chronic HCV infection described by the presence of the genomic HCV-RNA in liver biopsy and/or peripheral blood mononuclear cell (PBMC) samples, and undetectable levels or absence of HCV-RNA and in the absence or presence of anti HCV antibodies in the plasma specimens. The aim of the present study was to evaluate the occurrence of occult HCV infection (OCI) among Iranian subjects infected with human immunodeficiency virus (HIV) using RT-nested PCR. From March 2014 until April 2015, 109 Iranian patients with established HIV infection were enrolled in this cross-sectional study. After extraction of viral RNA from the plasma and PBMC samples, HCV-RNA status was examined by RT-nested PCR using primers from the 5'-NTR. HCV genotyping was conducted using RFLP analysis. For the confirmation of HCV genotyping by RFLP method, the PCR products were sequenced. Of the 109 patients, 50 were positive for antibodies against HCV. The HCV-RNA was detected in PBMC specimens in 6 (10.2%) out of the total 59 patients negative for anti-HCV Abs and undetectable plasma HCV-RNA and also from 4 (8.0%) out of the total 50 patients positive for anti-HCV Abs and undetectable plasma HCV-RNA. HCV genotyping analysis showed that 6 (60.0%) patients were infected with HCV subtype 3a, 3 (30.0%) were infected with HCV subtype 1a and 1 (10.0%) patient was infected with HCV subtype 1b. This study revealed the incidence of OCI (9.2%) in HIV-infected Iranian patients. Hence, designing prospective studies focusing on the detection of OCI in these patients would provide more information. J. Med. Virol. 88:1960-1966, 2016. © 2016 Wiley Periodicals, Inc. PMID:27463051

  10. Bovine respiratory disease model based on dual infections with infection with bovine viral diarrhea virus and bovine corona virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bovine respiratory disease complex (BRDC) is the leading cause of economic loss in the U.S. cattle industry. BRDC likely results from simultaneous or sequential infections with multiple pathogens including both viruses and bacteria. Bovine viral diarrhea virus (BVDV) and bovine corona virus (BoCV...

  11. Renal alterations in feline immunodeficiency virus (FIV)-infected cats: a natural model of lentivirus-induced renal disease changes.

    PubMed

    Poli, Alessandro; Tozon, Natasa; Guidi, Grazia; Pistello, Mauro

    2012-09-01

    Human immunodeficiency virus (HIV) is associated with several renal syndromes including acute and chronic renal failures, but the underlying pathogenic mechanisms are unclear. HIV and feline immunodeficiency virus (FIV) share numerous biological and pathological features, including renal alterations. We investigated and compared the morphological changes of renal tissue of 51 experimentally and 21 naturally infected cats. Compared to the latter, the experimentally infected cats exhibited some mesangial widening and glomerulonephritis, milder proteinuria, and lower tubular and interstitial alterations. The numbers of giant protein tubular casts and tubular microcysts were also lower. In contrast, diffuse interstitial infiltrates and glomerular and interstitial amyloidosis were detected only in naturally infected cats. Similar alterations are found in HIV infected patients, thus supporting the idea of a causative role of FIV infection in renal disease, and underlining the relevance of the FIV and its natural host as an animal model for investigating lentivirus-associated nephropathy. PMID:23170163

  12. Renal Alterations in Feline Immunodeficiency Virus (FIV)-Infected Cats: A Natural Model of Lentivirus-Induced Renal Disease Changes

    PubMed Central

    Poli, Alessandro; Tozon, Natasa; Guidi, Grazia; Pistello, Mauro

    2012-01-01

    Human immunodeficiency virus (HIV) is associated with several renal syndromes including acute and chronic renal failures, but the underlying pathogenic mechanisms are unclear. HIV and feline immunodeficiency virus (FIV) share numerous biological and pathological features, including renal alterations. We investigated and compared the morphological changes of renal tissue of 51 experimentally and 21 naturally infected cats. Compared to the latter, the experimentally infected cats exhibited some mesangial widening and glomerulonephritis, milder proteinuria, and lower tubular and interstitial alterations. The numbers of giant protein tubular casts and tubular microcysts were also lower. In contrast, diffuse interstitial infiltrates and glomerular and interstitial amyloidosis were detected only in naturally infected cats. Similar alterations are found in HIV infected patients, thus supporting the idea of a causative role of FIV infection in renal disease, and underlining the relevance of the FIV and its natural host as an animal model for investigating lentivirus-associated nephropathy. PMID:23170163

  13. Respiratory Syncytial Virus Infection in Adults

    PubMed Central

    Falsey, Ann R.; Walsh, Edward E.

    2000-01-01

    Respiratory syncytial virus (RSV) is now recognized as a significant problem in certain adult populations. These include the elderly, persons with cardiopulmonary diseases, and immunocompromised hosts. Epidemiological evidence indicates that the impact of RSV in older adults may be similar to that of nonpandemic influenza. In addition, RSV has been found to cause 2 to 5% of adult community-acquired pneumonias. Attack rates in nursing homes are approximately 5 to 10% per year, with significant rates of pneumonia (10 to 20%) and death (2 to 5%). Clinical features may be difficult to distinguish from those of influenza but include nasal congestion, cough, wheezing, and low-grade fever. Bone marrow transplant patients prior to marrow engraftment are at highest risk for pneumonia and death. Diagnosis of RSV infection in adults is difficult because viral culture and antigen detection are insensitive, presumably due to low viral titers in nasal secretions, but early bronchoscopy is valuable in immunosuppressed patients. Treatment of RSV in the elderly is largely supportive, whereas early therapy with ribavirin and intravenous gamma globulin is associated with improved survival in immunocompromised persons. An effective RSV vaccine has not yet been developed, and thus prevention of RSV infection is limited to standard infection control practices such as hand washing and the use of gowns and gloves. PMID:10885982

  14. Hepatitis B virus infection and intrahepatic cholangiocarcinoma

    PubMed Central

    Zhou, Hua-Bang; Hu, Jing-Yi; Hu, He-Ping

    2014-01-01

    Intrahepatic cholangiocarcinoma (ICC) is a devastating malignant tumor arising from the peripheral intrahepatic bile duct epithelium. The incidence and mortality of ICC is markedly increasing over the past two decades worldwide, though the cause for this rise in incidence is unclear, thus intensifying the search for alternative etiological agents and pathogenetic mechanisms. Hepatolithiasis, primary sclerosing cholangitis, parasitic infection (Opisthorchis viverrini or Clonorchis sinensis), fibropolycystic liver disease, and chemical carcinogen exposure are thought to be the risk factors for ICC. Nevertheless, the majority of ICC patients do not have any of these risk factors, and none of the established risk factors can explain the recent increasing trend of ICC. Therefore, identifying other risk factors may lead to the prevention and early detection of ICC. Chronic hepatitis B virus (HBV) infection is the predominant cause of hepatocellular carcinoma in HBV-endemic areas. This review discusses the evidence implicating chronic HBV infection as a likely etiology of ICC and the pathogenetic mechanisms that might be involved. PMID:24914333

  15. Giant Polymersome Protocells Dock with Virus Particle Mimics via Multivalent Glycan-Lectin Interactions.

    PubMed

    Kubilis, Artur; Abdulkarim, Ali; Eissa, Ahmed M; Cameron, Neil R

    2016-01-01

    Despite the low complexity of their components, several simple physical systems, including microspheres, coacervate droplets and phospholipid membrane structures (liposomes), have been suggested as protocell models. These, however, lack key cellular characteristics, such as the ability to replicate or to dock with extracellular species. Here, we report a simple method for the de novo creation of synthetic cell mimics in the form of giant polymeric vesicles (polymersomes), which are capable of behavior approaching that of living cells. These polymersomes form by self-assembly, under electroformation conditions, of amphiphilic, glycosylated block copolymers in aqueous solution. The glycosylated exterior of the resulting polymeric giant unilamellar vesicles (GUVs) allows their selective interaction with carbohydrate-binding receptor-functionalized particles, in a manner reminiscent of the cell-surface docking of virus particles. We believe that this is the first example of a simple protocell model displaying cell-like behavior through a native receptor-ligand interaction. PMID:27576579

  16. Giant Polymersome Protocells Dock with Virus Particle Mimics via Multivalent Glycan-Lectin Interactions

    PubMed Central

    Kubilis, Artur; Abdulkarim, Ali; Eissa, Ahmed M.; Cameron, Neil R.

    2016-01-01

    Despite the low complexity of their components, several simple physical systems, including microspheres, coacervate droplets and phospholipid membrane structures (liposomes), have been suggested as protocell models. These, however, lack key cellular characteristics, such as the ability to replicate or to dock with extracellular species. Here, we report a simple method for the de novo creation of synthetic cell mimics in the form of giant polymeric vesicles (polymersomes), which are capable of behavior approaching that of living cells. These polymersomes form by self-assembly, under electroformation conditions, of amphiphilic, glycosylated block copolymers in aqueous solution. The glycosylated exterior of the resulting polymeric giant unilamellar vesicles (GUVs) allows their selective interaction with carbohydrate-binding receptor-functionalized particles, in a manner reminiscent of the cell-surface docking of virus particles. We believe that this is the first example of a simple protocell model displaying cell-like behavior through a native receptor-ligand interaction. PMID:27576579

  17. Epidemiological and Virological Characterization of Influenza B Virus Infections.

    PubMed

    Sharabi, Sivan; Drori, Yaron; Micheli, Michal; Friedman, Nehemya; Orzitzer, Sara; Bassal, Ravit; Glatman-Freedman, Aharona; Shohat, Tamar; Mendelson, Ella; Hindiyeh, Musa; Mandelboim, Michal

    2016-01-01

    While influenza A viruses comprise a heterogeneous group of clinically relevant influenza viruses, influenza B viruses form a more homogeneous cluster, divided mainly into two lineages: Victoria and Yamagata. This divergence has complicated seasonal influenza vaccine design, which traditionally contained two seasonal influenza A virus strains and one influenza B virus strain. We examined the distribution of the two influenza B virus lineages in Israel, between 2011-2014, in hospitalized and in non-hospitalized (community) influenza B virus-infected patients. We showed that influenza B virus infections can lead to hospitalization and demonstrated that during some winter seasons, both influenza B virus lineages circulated simultaneously in Israel. We further show that the influenza B virus Yamagata lineage was dominant, circulating in the county in the last few years of the study period, consistent with the anti-Yamagata influenza B virus antibodies detected in the serum samples of affected individuals residing in Israel in the year 2014. Interestingly, we found that elderly people were particularly vulnerable to Yamagata lineage influenza B virus infections. PMID:27533045

  18. Epidemiological and Virological Characterization of Influenza B Virus Infections

    PubMed Central

    Sharabi, Sivan; Drori, Yaron; Micheli, Michal; Friedman, Nehemya; Orzitzer, Sara; Bassal, Ravit; Glatman-Freedman, Aharona; Shohat, Tamar; Mendelson, Ella; Hindiyeh, Musa; Mandelboim, Michal

    2016-01-01

    While influenza A viruses comprise a heterogeneous group of clinically relevant influenza viruses, influenza B viruses form a more homogeneous cluster, divided mainly into two lineages: Victoria and Yamagata. This divergence has complicated seasonal influenza vaccine design, which traditionally contained two seasonal influenza A virus strains and one influenza B virus strain. We examined the distribution of the two influenza B virus lineages in Israel, between 2011–2014, in hospitalized and in non-hospitalized (community) influenza B virus-infected patients. We showed that influenza B virus infections can lead to hospitalization and demonstrated that during some winter seasons, both influenza B virus lineages circulated simultaneously in Israel. We further show that the influenza B virus Yamagata lineage was dominant, circulating in the county in the last few years of the study period, consistent with the anti-Yamagata influenza B virus antibodies detected in the serum samples of affected individuals residing in Israel in the year 2014. Interestingly, we found that elderly people were particularly vulnerable to Yamagata lineage influenza B virus infections. PMID:27533045

  19. Transcriptional Profiling of the Immune Response to Marburg Virus Infection

    PubMed Central

    Yen, Judy; Caballero, Ignacio S.; Garamszegi, Sara; Malhotra, Shikha; Lin, Kenny; Hensley, Lisa; Goff, Arthur J.

    2015-01-01

    ABSTRACT Marburg virus is a genetically simple RNA virus that causes a severe hemorrhagic fever in humans and nonhuman primates. The mechanism of pathogenesis of the infection is not well understood, but it is well accepted that pathogenesis is appreciably driven by a hyperactive immune response. To better understand the overall response to Marburg virus challenge, we undertook a transcriptomic analysis of immune cells circulating in the blood following aerosol exposure of rhesus macaques to a lethal dose of Marburg virus. Using two-color microarrays, we analyzed the transcriptomes of peripheral blood mononuclear cells that were collected throughout the course of infection from 1 to 9 days postexposure, representing the full course of the infection. The response followed a 3-stage induction (early infection, 1 to 3 days postexposure; midinfection, 5 days postexposure; late infection, 7 to 9 days postexposure) that was led by a robust innate immune response. The host response to aerosolized Marburg virus was evident at 1 day postexposure. Analysis of cytokine transcripts that were overexpressed during infection indicated that previously unanalyzed cytokines are likely induced in response to exposure to Marburg virus and further suggested that the early immune response is skewed toward a Th2 response that would hamper the development of an effective antiviral immune response early in disease. Late infection events included the upregulation of coagulation-associated factors. These findings demonstrate very early host responses to Marburg virus infection and provide a rich data set for identification of factors expressed throughout the course of infection that can be investigated as markers of infection and targets for therapy. IMPORTANCE Marburg virus causes a severe infection that is associated with high mortality and hemorrhage. The disease is associated with an immune response that contributes to the lethality of the disease. In this study, we investigated how the

  20. Sofosbuvir treatment and hepatitis C virus infection.

    PubMed

    Nakamura, Masato; Kanda, Tatsuo; Haga, Yuki; Sasaki, Reina; Wu, Shuang; Nakamoto, Shingo; Yasui, Shin; Arai, Makoto; Imazeki, Fumio; Yokosuka, Osamu

    2016-01-28

    Hepatitis C virus (HCV) infection is a serious problem worldwide. The use of interferon-based therapy has made HCV eradication challenging. The recent appearance of direct-acting antiviral agents (DAAs) has changed HCV therapy. Combining the use of DAAs with peginterferon and ribavirin has improved treatment efficacy. Furthermore, the combination of different orally administered DAAs has enabled interferon-free therapy with much higher efficacy and safety. In particular, sofosbuvir, a nucleotide-based NS5B inhibitor, prevents HCV RNA synthesis by acting as a "chain terminator". Treatment with sofosbuvir has attained an extremely high rate of sustained virologic response. The current review summarizes the efficacy and safety of sofosbuvir therapy. PMID:26839641

  1. Sofosbuvir treatment and hepatitis C virus infection

    PubMed Central

    Nakamura, Masato; Kanda, Tatsuo; Haga, Yuki; Sasaki, Reina; Wu, Shuang; Nakamoto, Shingo; Yasui, Shin; Arai, Makoto; Imazeki, Fumio; Yokosuka, Osamu

    2016-01-01

    Hepatitis C virus (HCV) infection is a serious problem worldwide. The use of interferon-based therapy has made HCV eradication challenging. The recent appearance of direct-acting antiviral agents (DAAs) has changed HCV therapy. Combining the use of DAAs with peginterferon and ribavirin has improved treatment efficacy. Furthermore, the combination of different orally administered DAAs has enabled interferon-free therapy with much higher efficacy and safety. In particular, sofosbuvir, a nucleotide-based NS5B inhibitor, prevents HCV RNA synthesis by acting as a “chain terminator”. Treatment with sofosbuvir has attained an extremely high rate of sustained virologic response. The current review summarizes the efficacy and safety of sofosbuvir therapy. PMID:26839641

  2. Glucose abnormalities in hepatitis C virus infection.

    PubMed

    Huang, Jee-Fu; Yu, Ming-Lung; Dai, Chia-Yen; Chuang, Wan-Long

    2013-02-01

    Hepatitis C virus (HCV) infection is one of the most important causes of cirrhosis and hepatocellular carcinoma and has a tremendous impact on public health worldwide. HCV is both hepatotropic and lymphotropic. Replication of HCV in diseased extrahepatic organs and tissues may either trigger latent autoimmunity or induce autoimmune disorders. In addition to established liver injury, type 2 diabetes mellitus (T2DM) is an important feature of extrahepatic metabolic disorders which is attributed to HCV infection. It also has some impact on the disease activity, disease course, clinical outcomes, and treatment efficacy of antiviral therapy. Previous experimental and clinical findings have highly suggested that HCV per se is diabetogenic. The cause-effect interaction between a common endocrine disorder and an infectious disease is an important issue to elucidate. Although the precise mechanisms whereby HCV infection leads to insulin resistance (IR) and glucose abnormalities are not entirely clear, it differs from the usual pathogenesis of T2DM in those with non-HCV liver diseases. This review initially highlights epidemiological and pathophysiological studies addressing the mutual link between chronic HCV infection (CHC) and T2DM. The characteristics of glucose abnormalities in this special population are depicted from the current evidence. The mutual roles of IR and CHC with respect to the prediction of treatment efficacy, how treatment response affects IR, and the role of pancreatic beta cell function in the entire suite are discussed. With the rapid progression of antiviral therapy for CHC in the past decade, we have also listed some points of future perspective in this issue. PMID:23347806

  3. Susceptibility of mouse macrophage J774 to dengue virus infection.

    PubMed

    Moreno-Altamirano, María M B; Sánchez-García, F Javier; Legorreta-Herrera, Martha; Aguilar-Carmona, Israel

    2007-01-01

    The aim of this study was to investigate whether the J774 mouse macrophage cell line could be used as an in vitro model for dengue virus infection (DENV). After 3 days, infection in J774 cells was assessed by detecting dengue virus non-structural protein 1 (NSP-1) production either by dot blot or indirect immunofluorescence assay (IFA) of saponine-permeabilized J774 cells and then confirmed by RT-PCR (171 bp product, corresponding to the DENV-2 core). Based on the presence of NSP-1 in infected but not in non-infected cells by both IFA and dot blot, as well as the amplification of a 171-bp DENV-2-specific RT-PCR product exclusively in the infected cells, the J774 cell line was found to be permissive for dengue virus infection. As far as we know, this is the first report that the J774 mouse macrophage cell line is infected with dengue virus and, thus, that it can be used as an alternative in vitro model for dengue virus infection studies. This finding could help to further elucidate the mechanisms involved in dengue virus infection and pathogenesis. PMID:17356302

  4. Unfolded protein response in hepatitis C virus infection

    PubMed Central

    Chan, Shiu-Wan

    2014-01-01

    Hepatitis C virus (HCV) is a single-stranded, positive-sense RNA virus of clinical importance. The virus establishes a chronic infection and can progress from chronic hepatitis, steatosis to fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). The mechanisms of viral persistence and pathogenesis are poorly understood. Recently the unfolded protein response (UPR), a cellular homeostatic response to endoplasmic reticulum (ER) stress, has emerged to be a major contributing factor in many human diseases. It is also evident that viruses interact with the host UPR in many different ways and the outcome could be pro-viral, anti-viral or pathogenic, depending on the particular type of infection. Here we present evidence for the elicitation of chronic ER stress in HCV infection. We analyze the UPR signaling pathways involved in HCV infection, the various levels of UPR regulation by different viral proteins and finally, we propose several mechanisms by which the virus provokes the UPR. PMID:24904547

  5. Antibody dependent enhancement of frog virus 3 infection

    PubMed Central

    2010-01-01

    Background Viruses included in the family Iridoviridae are large, icosahedral, dsDNA viruses that are subdivided into 5 genera. Frog virus 3 (FV3) is the type species of the genus Ranavirus and the best studied iridovirus at the molecular level. Typically, antibodies directed against a virus act to neutralize the virus and limit infection. Antibody dependent enhancement occurs when viral antibodies enhance infectivity of the virus rather than neutralize it. Results Here we show that anti-FV3 serum present at the time of FV3 infection enhances infectivity of the virus in two non-immune teleost cell lines. We found that antibody dependent enhancement of FV3 was dependent on the Fc portion of anti-FV3 antibodies but not related to complement. Furthermore, the presence of anti-FV3 serum during an FV3 infection in a non-immune mammalian cell line resulted in neutralization of the virus. Our results suggest that a cell surface receptor specific to teleost cell lines is responsible for the enhancement. Conclusions This report represents the first evidence of antibody dependent enhancement in iridoviruses. The data suggests that anti-FV3 serum can either neutralize or enhance viral infection and that enhancement is related to a novel antibody dependent enhancement pathway found in teleosts that is Fc dependent. PMID:20167100

  6. Hepatitis E virus infection in the HIV-positive patient.

    PubMed

    Debes, Jose D; Pisano, Maria Belen; Lotto, Martin; Re, Viviana

    2016-07-01

    Hepatitis E virus (HEV) is a RNA virus that can cause hepatitis. In immunocompetent individuals, infection with HEV usually leads to asymptomatic seroconversion. However, in immunosuppressed patients, such as transplant recipients, HEV can develop into a chronic infection. Studies regarding the seroprevalence and clinical implications of HEV in patients infected with the human immunodeficiency virus (HIV) are conflicting. Levels of CD4 count in blood seem to be the most widely associated risk factor, while other factors such as meat consumption or proximity to animals are less clearly associated with HEV infection. Progression to chronicity, as well as extrahepatic manifestations of HEV seem rare in HIV, and the implications of HEV in liver disease progression are poorly understood in the HIV-infected. In this review we describe the epidemiology, risk factors, and clinical implications of HEV infection in individuals infected with HIV. PMID:27243210

  7. Analysis of in vivo dynamics of influenza virus infection in mice using a GFP reporter virus

    PubMed Central

    Manicassamy, Balaji; Manicassamy, Santhakumar; Belicha-Villanueva, Alan; Pisanelli, Giuseppe; Pulendran, Bali; García-Sastre, Adolfo

    2010-01-01

    Influenza A virus is being extensively studied because of its major impact on human and animal health. However, the dynamics of influenza virus infection and the cell types infected in vivo are poorly understood. These characteristics are challenging to determine, partly because there is no efficient replication-competent virus expressing an easily traceable reporter gene. Here, we report the generation of a recombinant influenza virus carrying a GFP reporter gene in the NS segment (NS1-GFP virus). Although attenuated when compared with wild-type virus, the NS1-GFP virus replicates efficiently in murine lungs and shows pathogenicity in mice. Using whole-organ imaging and flow cytometry, we have tracked the dynamics of influenza virus infection progression in mice. Imaging of murine lungs shows that infection starts in the respiratory tract in areas close to large conducting airways and later spreads to deeper sections of the lungs. In addition to epithelial cells, we found GFP-positive antigen-presenting cells, such as CD11b+CD11c−, CD11b−CD11c+, and CD11b+CD11c+, as early as 24 h after intranasal infection. In addition, a significant proportion of NK and B cells were GFP positive, suggesting active infection of these cells. We next tested the effects of the influenza virus inhibitors oseltamivir and amantadine on the kinetics of in vivo infection progression. Treatment with oseltamivir dramatically reduced influenza infection in all cell types, whereas, surprisingly, amantadine treatment more efficiently blocked infection in B and NK cells. Our results demonstrate high levels of immune cells harboring influenza virus antigen during viral infection and cell-type–specific effects upon treatment with antiviral agents, opening additional avenues of research in the influenza virus field. PMID:20534532

  8. Absence of Active Hepatitis C Virus Infection in Human Immunodeficiency Virus Clinics in Zambia and Mozambique

    PubMed Central

    Wandeler, Gilles; Mulenga, Lloyd; Hobbins, Michael; Joao, Candido; Sinkala, Edford; Hector, Jonas; Aly, Musa; Chi, Benjamin H.; Egger, Matthias; Vinikoor, Michael J.

    2016-01-01

    Few studies have evaluated the prevalence of replicating hepatitis C virus (HCV) infection in sub-Saharan Africa. Among 1812 individuals infected with human immunodeficiency virus, no patient in rural Mozambique and 4 patients in urban Zambia were positive for anti-HCV antibodies. Of these, none had confirmed HCV replication. PMID:27047986

  9. Hemophagocytic lymphohistiocytosis associated with SFTS virus infection

    PubMed Central

    Oh, Hong Sang; Kim, Moonsuk; Lee, Jeong-Ok; Kim, Haeryoung; Kim, Eu Suk; Park, Kyoung Un; Kim, Hong Bin; Song, Kyoung-Ho

    2016-01-01

    Abstract Background: Severe fever with thrombocytopenia syndrome (SFTS) is a new emerging zoonosis. Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening syndrome caused by hyperinflammation. Here, we report the case of SFTS-associated HLH. Case summary: A 62-year-old man was admitted to local hospital with 8 days of fever and chill. He had leukopenia, thrombocytopenia, and developed seizure. An attending physician examined bone marrow to rule out hematologic malignancy. He was transferred to tertiary referral hospital for suspicious HLH. We decided to confirm its histologic feature for sure. Bone marrow and liver biopsy showed hemophagocyotic histiocytes. Serological tests for other infections were all negative except SFTS virus polymerase chain reactions (PCRs) as positive from serum, bone marrow, bronchoalveolar lavage fluid, and liver biopsy specimen. A definitive diagnosis was SFTS-associated HLH. During 2 weeks of conservative treatment, he succeeded in recovery from multiple organ failure. Conclusion: SFTS should be considered one of differential diagnosis of HLH. In certain endemic areas, SFTS infection deserves clinicians’ attention because it can be presented hematologic diseases as HLH. PMID:27495089

  10. Development of vaccines for prevention of Ebola virus infection.

    PubMed

    Ye, Ling; Yang, Chinglai

    2015-02-01

    Ebola virus infection causes severe hemorrhagic fevers with high fatality rates up to 90% in humans, for which no effective treatment is currently available. The ongoing Ebola outbreak in West Africa that has caused over 14,000 human infections and over 5000 deaths underscores its serious threat to the public health. While licensed vaccines against Ebola virus infection are still not available, a number of vaccine approaches have been developed and shown to protect against lethal Ebola virus infection in animal models. This review aims to summarize the advancement of different strategies for Ebola vaccine development with a focus on the discussion of their protective efficacies and possible limitations. In addition, the development of animal models for efficacy evaluation of Ebola vaccines and the mechanism of immune protection against Ebola virus infection are also discussed. PMID:25526819

  11. Nontyphoidal Salmonellosis, Human Immunodeficiency Virus Infection, and Ischemic Stroke

    PubMed Central

    Piggott, Damani A.; Carroll, Karen C.; Lim, Michael; Melia, Michael T.

    2016-01-01

    Nontyphoidal Salmonella infection and stroke are major causes of morbidity and mortality worldwide, with increased risk in the human immunodeficiency virus (HIV)-infected population. We report a rare case of ischemic stroke associated with Salmonella enteritidis subdural empyema in an older HIV-infected patient with multimorbidity, despite surgery and treatment with susceptible antimicrobial drugs. PMID:27419176

  12. Nontyphoidal Salmonellosis, Human Immunodeficiency Virus Infection, and Ischemic Stroke.

    PubMed

    Piggott, Damani A; Carroll, Karen C; Lim, Michael; Melia, Michael T

    2016-04-01

    Nontyphoidal Salmonella infection and stroke are major causes of morbidity and mortality worldwide, with increased risk in the human immunodeficiency virus (HIV)-infected population. We report a rare case of ischemic stroke associated with Salmonella enteritidis subdural empyema in an older HIV-infected patient with multimorbidity, despite surgery and treatment with susceptible antimicrobial drugs. PMID:27419176

  13. mRNA maturation in giant viruses: variation on a theme.

    PubMed

    Priet, Stéphane; Lartigue, Audrey; Debart, Françoise; Claverie, Jean-Michel; Abergel, Chantal

    2015-04-20

    Giant viruses from the Mimiviridae family replicate entirely in their host cytoplasm where their genes are transcribed by a viral transcription apparatus. mRNA polyadenylation uniquely occurs at hairpin-forming palindromic sequences terminating viral transcripts. Here we show that a conserved gene cluster both encode the enzyme responsible for the hairpin cleavage and the viral polyA polymerases (vPAP). Unexpectedly, the vPAPs are homodimeric and uniquely self-processive. The vPAP backbone structures exhibit a symmetrical architecture with two subdomains sharing a nucleotidyltransferase topology, suggesting that vPAPs originate from an ancestral duplication. A Poxvirus processivity factor homologue encoded by Megavirus chilensis displays a conserved 5'-GpppA 2'O methyltransferase activity but is also able to internally methylate the mRNAs' polyA tails. These findings elucidate how the arm wrestling between hosts and their viruses to access the translation machinery is taking place in Mimiviridae. PMID:25779049

  14. Human T-cell lymphotropic virus type III infection of the central nervous system: a preliminary in situ analysis

    SciTech Connect

    Stoler, M.H.; Eskin, T.A.; Benn, S.; Angerer, R.C.; Angerer, L.M.

    1986-11-07

    Patients with acquired immunodeficiency syndrome (AIDS) are subject to a spectrum of central nervous system (CNS) disorders. Recent evidence implicates the human T-cell lymphotropic virus type III (HTLV-III) in the pathogenesis of some of these illnesses, although the cells infected by the virus have yet to be identified. Using in situ hybridization, the authors examined brain tissue from two patients with AIDS encephalopathy for the presence of HTLV-III RNA. In both cases, viral RNA was detected and concentrated in, though not limited to, the white matter. The CNS cells most frequently infected included macrophages, pleomorphic microglia, and multinucleated giant cells. Less frequently, cells morphologically consistent with astrocytes, oligodendroglia, and rarely neurons were also infected. The findings strengthen the association of HTLV-III with the pathogenesis of AIDS encephalopathy. In situ hybridization can be applied to routinely prepared biopsy tissue in the diagnosis of HTLV-III infection of the CNS.

  15. Molecular diagnosis of Baylisascaris schroederi infections in giant panda (Ailuropoda melanoleuca) feces using PCR.

    PubMed

    Zhou, Xuan; Yu, Hua; Wang, Ning; Xie, Yue; Liang, Yi-nan; Li, De-sheng; Wang, Cheng-dong; Chen, Si-jie; Yan, Yu-bo; Gu, Xiao-bin; Wang, Shu-xian; Peng, Xue-rong; Yang, Guang-you

    2013-10-01

    The helminth Baylisascaris schroederi is one of the most harmful parasites infecting giant pandas (Ailuropoda melanoleuca). It is therefore important to develop an exact diagnostic technique to detect this parasite. Using a known number (1, 2, 3, 4, 5, 10, 25, 50, 100) of feces-isolated B. schroederi egg and adult DNA, we developed a PCR to detect a portion of the mitochondrial 12S rRNA and applied it to giant panda fecal samples. The method was sufficiently sensitive to detect B. schroederi DNA from isolated eggs in a fecal sample with a detection threshold of one egg. We detected B. schroederi in 88% of fecal samples, 30% higher than the conventional flotation technique. No cross-reactivity with other common nematode DNA was detected. Our PCR assay may constitute a valuable alternative for the diagnosis of B. schroederi infections. PMID:24502740

  16. Role of oxidative stress in rabies virus infection.

    PubMed

    Jackson, Alan C; Kammouni, Wafa; Fernyhough, Paul

    2011-01-01

    Recent studies in an experimental model of rabies indicated that there are major structural changes in the brain involving neuronal processes that are associated with severe clinical disease. Cultured adult mouse dorsal root ganglion (DRG) neurons are a good in vitro model for studying the mechanisms involved in rabies virus-induced degeneration of neurites (axons) because, unlike other neuronal cell types, these neurons are fairly permissive to rabies virus infection. DRG neurons infected with the challenge virus standard-11 (CVS) strain of rabies virus show axonal swellings and immunostaining for 4-hydroxy-2-nonenal (4-HNE), indicating evidence of lipid peroxidation associated with oxidative stress, and also reduced axonal growth in comparison with mock-infected DRG neurons. Treatment with the antioxidant N-acetyl cysteine prevented the reduction in axonal outgrowth that occurred with CVS infection. The axonal swellings with 4-HNE-labeled puncta were found to be associated with aggregations of actively respiring mitochondria. We postulate that rabies virus infection likely induces mitochondrial dysfunction resulting in oxidative stress and degenerative changes involving neuronal processes. This mitochondrial dysfunction may be the result of either direct or indirect effects of the virus on the mitochondrial electron-transport chain or it may occur through other mechanisms. Further investigations are needed to gain a better understanding of the basic mechanisms involved in the oxidative damage associated with rabies virus infection. This information may prove helpful in the design of future therapeutic effects for this dreaded ancient disease. PMID:21601046

  17. Prevalence of Hepatitis Virus Infections in an Institution for Persons with Developmental Disabilities.

    ERIC Educational Resources Information Center

    Woodruff, Bradley A.; Vazquez, Elizabeth

    2002-01-01

    A study involving 1,235 residents of Sonoma Developmental Center found 3 residents had hepatitis C virus infections, and 633 had past or current hepatitis B virus infections. The prevalence of hepatitis B virus infection rose rapidly with longer residence in institutions. Hepatitis A virus infection had occurred in 494 residents. (Contains…

  18. Border disease in sheep caused by transmission of virus from cattle persistently infected with bovine virus diarrhoea virus.

    PubMed

    Carlsson, U

    1991-02-16

    Two outbreaks of border disease occurred on farms with sheep flocks and breeding cattle. The infection of the pregnant sheep was probably caused by transmission of virus from calves persistently infected with non-cytopathic bovine virus diarrhoea virus (BVDV) which were kept in close confinement with the ewes during mid-pregnancy. Border disease was also induced experimentally in eight lambs by exposing their dams at 38 to 78 days of gestation to a heifer persistently infected with BVDV. Both the natural and the experimental infections were characterised by typical signs such as 'hairy-shaker' lambs and high lamb mortality. The diagnosis was confirmed by virus isolations from live-born lambs, seroconversion and pathology. The study supports the assertion that cattle persistently infected with BVDV and in close contact with pregnant sheep, are an important source of strains of virus capable of causing border disease. PMID:1851350

  19. 78 FR 33848 - Draft Guidance for Industry on Human Immunodeficiency Virus-1 Infection: Developing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-05

    ... HUMAN SERVICES Food and Drug Administration Draft Guidance for Industry on Human Immunodeficiency Virus... availability of a draft guidance for industry entitled ``Human Immunodeficiency Virus-1 Infection: Developing... guidance for industry entitled ``Human Immunodeficiency Virus-1 Infection: Developing Antiretroviral...

  20. Modeling multiple infection of cells by viruses: challenges and insights

    PubMed Central

    Phan, Dustin; Wodarz, Dominik

    2015-01-01

    The multiple infection of cells with several copies of a given virus has been demonstrated in experimental systems, and has been subject to previous mathematical modeling approaches. Such models, especially those based on ordinary differential equations, can be characterized by difficulties and pitfalls. One such difficulty arises from what we refer to as multiple infection cascades. That is, such models subdivide the infected cell population into sub-populations that are carry i viruses, and each sub-population can in principle always be further infected to contain i+1 viruses. In order to study the model with numerical simulations, the infection cascade needs to be cut artificially, and this can influence the results. This is shown here in the context of the simplest setting that involves a single, homogeneous virus population. If the viral replication rate is sufficiently fast, then most infected cells will accumulate in the last member of the infection cascade, leading to incorrect numerical results. This can be observed even with relatively long infection cascades, and in this case computational costs associated with a sufficiently long infection cascade can render this approach impractical. We subsequently examine a more complex scenario where two virus types / strains with different fitness are allowed to compete. Again, we find that the length of the infection cascade can have a crucial influence on the results. Competitive exclusion can be observed for shorter infection cascades, while coexistence can be observed for longer infection cascades. More subtly, the length of the infection cascade can influence the equilibrium level of the populations in numerical simulations. Studying the model in a parameter regime where an increase in the infection cascade length does not influence the results, we examine the effect of multiple infection on the outcome of competition. We find that multiple infection can promote coexistence of virus types if there is a degree

  1. Zika virus productively infects primary human placenta-specific macrophages

    PubMed Central

    Jurado, Kellie Ann; Simoni, Michael K.; Tang, Zhonghua; Uraki, Ryuta; Hwang, Jesse; Householder, Sarah; Wu, Mingjie; Lindenbach, Brett D.; Abrahams, Vikki M.; Guller, Seth; Fikrig, Erol

    2016-01-01

    The strong association of Zika virus infection with congenital defects has led to questions of how a flavivirus is capable of crossing the placental barrier to reach the fetal brain. Here, we demonstrate permissive Zika virus infection of primary human placental macrophages, commonly referred to as Hofbauer cells, and placental villous fibroblasts. We also demonstrate Zika virus infection of Hofbauer cells within the context of the tissue ex vivo using term placental villous explants. In addition to amplifying infectious virus within a usually inaccessible area, the putative migratory activities of Hofbauer cells may aid in dissemination of Zika virus to the fetal brain. Understanding the susceptibility of placenta-specific cell types will aid future work around and understanding of Zika virus–associated pregnancy complications. PMID:27595140

  2. Immune responses of infants to infection with respiratory viruses and live attenuated respiratory virus candidate vaccines.

    PubMed

    Crowe, J E

    1998-01-01

    Respiratory viruses such as respiratory syncytial virus (RSV), the parainfluenza viruses (PIV), and the influenza viruses cause severe lower respiratory tract diseases in infants and children throughout the world. Experimental live attenuated vaccines for each of these viruses are being developed for intranasal administration in the first weeks or months of life. A variety of promising RSV, PIV-3, and influenza virus vaccine strains have been developed by classical biological methods, evaluated extensively in preclinical and clinical studies, and shown to be attenuated and genetically stable. The ongoing clinical evaluation of these vaccine candidates, coupled with recent major advances in the ability to develop genetically engineered viruses with specified mutations, may allow the rapid development of respiratory virus strains that possess ideal levels of replicative capacity and genetic stability in vivo. A major remaining obstacle to successful immunization of infants against respiratory virus associated disease may be the relatively poor immune response of very young infants to primary virus infection. This paper reviews the immune correlates of protection against disease caused by these viruses, immune responses of infants to naturally-acquired infection, and immune responses of infants to experimental infection with candidate vaccine viruses. PMID:9711783

  3. Edible bird's nest extract inhibits influenza virus infection.

    PubMed

    Guo, Chao-Tan; Takahashi, Tadanobu; Bukawa, Wakoto; Takahashi, Noriko; Yagi, Hirokazu; Kato, Koichi; Hidari, Kazuya I-P Jwa; Miyamoto, Daisei; Suzuki, Takashi; Suzuki, Yasuo

    2006-07-01

    Edible bird's nest (EBN) is the nest of the swift that is made from its saliva. Although EBN has been widely used for enhancing immunocompetence, its antiviral efficacy has not been studied in detail. We found that EBN extract could strongly inhibit infection with influenza viruses in a host range-independent manner when it was hydrolyzed with Pancreatin F. Western blotting assay showed that the EBN extract bound to influenza virus. Furthermore, EBN extract could neutralize the infection of MDCK cells with influenza viruses and inhibit hemagglutination of influenza viruses to erythrocytes, but it could not inhibit the activity of influenza virus sialidase. Fluorometric HPLC indicated that the major molecular species of sialic acid in EBN is N-acetylneuraminic acid. The results suggest that EBN is a safe and valid natural source for the prevention of influenza viruses. PMID:16581142

  4. The Impact of Wolbachia on Virus Infection in Mosquitoes

    PubMed Central

    Johnson, Karyn N.

    2015-01-01

    Mosquito-borne viruses such as dengue, West Nile and chikungunya viruses cause significant morbidity and mortality in human populations. Since current methods are not sufficient to control disease occurrence, novel methods to control transmission of arboviruses would be beneficial. Recent studies have shown that virus infection and transmission in insects can be impeded by co-infection with the bacterium Wolbachia pipientis. Wolbachia is a maternally inherited endosymbiont that is commonly found in insects, including a number of mosquito vector species. In Drosophila, Wolbachia mediates antiviral protection against a broad range of RNA viruses. This discovery pointed to a potential strategy to interfere with mosquito transmission of arboviruses by artificially infecting mosquitoes with Wolbachia. This review outlines research on the prevalence of Wolbachia in mosquito vector species and the impact of antiviral effects in both naturally and artificially Wolbachia-infected mosquitoes. PMID:26556361

  5. Update on Human Immunodeficiency Virus (HIV)-2 Infection

    PubMed Central

    Campbell-Yesufu, Omobolaji T.

    2011-01-01

    Infection with human immunodeficiency virus type 2 (HIV-2) occurs mainly in West Africa, but an increasing number of cases have been recognized in Europe, India, and the United States. In this era of global integration, clinicians must be aware of when to consider the diagnosis of HIV-2 infection and how to test for this virus. Although there is debate regarding when therapy should be initiated and which regimen should be chosen, recent trials have provided important information on treatment options for HIV-2 infection. In this review, we present information on recent clinical advances in our understanding of HIV-2 infection and highlight remaining diagnostic and therapeutic challenges. PMID:21367732

  6. Ultrastructural studies on dengue virus infection of human lymphoblasts.

    PubMed Central

    Sriurairatna, S; Bhamarapravati, N; Diwan, A R; Halstead, S B

    1978-01-01

    Ultrastructural studies of dengue-2 virus-infected lymphoblastoid Raji cells showed that the virus induced an increase in the size of the rough endoplasmic reticula (RER) and that the replication of the virus was confined to the cisternae of these RER. The proliferating RER formed cytoplasmic inclusions that could be seen by light microscopy. This observation could be used as evidence of a cytopathogenic effect of dengue virus on infected Rajii cells in routine cultures. Accumulation of virions in the infected cells was minimal in comparison with other cell systems, however. Sporadic clusters of mature virions were often seen on the plasma membrane. These extracellular virions were distributed adjacent to the virus-bearing RER and were presumably released virions. Vertical transmission of the virus was evident in mitotic lymphoblasts. The replication pattern of dengue virus in lymphoblastoid cells suggests that efforts should be made to determine whether blast-transformed lymphocytes, numerous in secondary dengue infections, support dengue virus replication in vivo. Images PMID:669791

  7. The naming of Potato virus Y strains infecting potato

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potato virus Y (PVY) strain groups are based on host-response and resistance-gene interactions. The strain groups PVYO, PVYC and PVYN are well-established for the isolates infecting potato in the field. A switch in the emphasis from host response to nucleotide sequence differences in the virus genom...

  8. EFFECT OF CHLORINE TREATMENT ON INFECTIVITY OF HEPATITIS A VIRUS

    EPA Science Inventory

    This study examined the effect of chlorine treatment on the infectivity of hepatitis A virus (HAV). Prodromal chimpanzee feces, shown to induce hepatitis in marmosets (Saguinus sp.), was clarified, and the virus was precipitated with 7% polyethylene glycol 6000, harvested and res...

  9. Swine as a model for influenza A virus infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Influenza A viruses (IAV) infect a variety of hosts, including humans, swine, and various avian species. The annual influenza disease burden in the human population remains significant even with current vaccine usage and much about the pathogenesis and transmission of influenza viruses in human rema...

  10. Zucchini tigre mosaic virus infection of cucurbits in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zucchini tigre mosaic virus (ZTMV) was identified infecting cucurbits in Florida in 2002 and again in 2015. This is the first report of ZTMV in the U.S. This report provides an overview of this emerging virus for growers, extension workers, crop consultants, and research and regulatory scientists....

  11. Whitefly Transmission of a New Virus Infecting Cucurbits in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A virus isolated from squash collected in Hillsborough County, FL in 2003, which was subsequently determined to be an ipomovirus, was transmitted by the silverleaf whitefly, Bemisia tabaci B strain in laboratory experiments. The virus was acquired by whiteflies after a 3-h access period on infected ...

  12. The Human Immunodeficiency Virus: Infectivity and Mechanisms of Pathogenesis.

    ERIC Educational Resources Information Center

    Fauci, Anthony S.

    1988-01-01

    Discusses how the infection of the human immunodeficiency virus (HIV) results in a profound immunosuppression due predominantly to a selective depletion of helper/inducer T lymphocytes that express the receptor for the virus, as well as neuropsychiatric abnormalities in the brain. (TW)

  13. Ocular syphilis in patients with Human Immunodeficiency Virus infection.

    PubMed

    Mitchell, John P; Huang, Lynn L; Rosberger, Daniel F

    2015-06-01

    As Acquired Immunodeficiency Disease (AIDS) turns thirty-years old, much progress has been made. 56,000 new cases of the Human Immunodeficiency Virus (HIV) infection are expected in Americans this year. At least half or more will be in African Americans. Reports of the association between syphilis and HIV infection are well documented. We present a case of bilateral optic neuritis and panuveitis as the initial presentation in a previously undiagnosed patient with human immunodeficiency virus (HIV) and syphilis. PMID:27269502

  14. A recombinant rabies virus expressing vesicular stomatitis virus glycoprotein fails to protect against rabies virus infection

    PubMed Central

    Foley, Heather D.; McGettigan, James P.; Siler, Catherine A.; Dietzschold, Bernhard; Schnell, Matthias J.

    2000-01-01

    To investigate the importance of the rabies virus (RV) glycoprotein (G) in protection against rabies, we constructed a recombinant RV (rRV) in which the RV G ecto- and transmembrane domains were replaced with the corresponding regions of vesicular stomatitis virus (VSV) glycoprotein (rRV-VSV-G). We were able to recover rRV-VSV-G and found that particle production was equal to rRV. However, the budding of the chimeric virus was delayed and infectious titers were reduced 10-fold compared with the parental rRV strain containing RV G. Biochemical analysis showed equal replication rates of both viruses, and similar amounts of wild-type and chimeric G were present in the respective viral particles. Additional studies were performed to determine whether the immune response against rRV-VSV-G was sufficient to protect against rabies. Mice were primed with rRV or rRV-VSV-G and challenged with a pathogenic strain of RV 12 days later. Similar immune responses against the internal viral proteins of both viruses indicated successful infection. All mice receiving the rRV vaccine survived the challenge, whereas immunization with rRV-VSV-G did not induce protection. The results confirm the crucial role of RV G in an RV vaccine. PMID:11114165

  15. Epidemiology of prolonged testicular infections with bovine viral diarrhea virus.

    PubMed

    Givens, M Daniel; Riddell, Kay P; Edmondson, Misty A; Walz, Paul H; Gard, Julie A; Zhang, Yijing; Galik, Patricia K; Brodersen, Bruce W; Carson, Robert L; Stringfellow, David A

    2009-10-20

    Previously, bovine viral diarrhea virus (BVDV) had been found in prolonged testicular infections following acute infection of immunocompetent bulls. The primary purpose of this research was to evaluate the production and maintenance of prolonged testicular infections after exposure to BVDV of seronegative bulls in varying circumstances. The secondary objective was to initiate assessment of the potential for transmission of BVDV via semen of bulls exhibiting a prolonged testicular infection. In total, 10 research trials were conducted. The first trial examined the duration of detectable virus in semen after intranasal inoculation of peri-pubertal bulls. The second to fifth trials examined the potential for prolonged testicular infections resulting from natural exposure of seronegative bulls to persistently infected heifers. In the last five trials, the potential for viral transmission from bulls exhibiting prolonged testicular infections to a small number of exposed animals (n=28) was evaluated. Results of this research demonstrated that prolonged testicular infections could result in detection of viral RNA in semen for 2.75 years with infectious virus grown from testicular tissue 12.5 months after viral exposure. A type 1b strain of BVDV caused prolonged testicular infection after natural exposure of seronegative bulls to a persistently infected heifer. However, transmission of BVDV to susceptible animals was not detected in the final five trials of this research. In conclusion, BVDV can persist in testicular tissue after acute infection for several years, but the potential for viral transmission from these prolonged testicular infections appears to be low. PMID:19473788

  16. Analysis of resistance and tolerance to virus infection in Drosophila.

    PubMed

    Merkling, Sarah H; van Rij, Ronald P

    2015-07-01

    Host defense to virus infection involves both resistance mechanisms that reduce viral burden and tolerance mechanisms that limit detrimental effects of infection. The fruit fly, Drosophila melanogaster, has emerged as a model for identifying and characterizing the genetic basis of resistance and tolerance. This protocol describes how to analyze host responses to virus infection in Drosophila, and it covers the preparation of virus stocks, experimental inoculation of flies and assessment of host survival and virus production, which are indicative of resistance or tolerance. It also provides guidance on how to account for recently identified confounding factors, including natural genetic variation in the pastrel locus and contamination of fly stocks with persistent viruses and the symbiotic bacterium Wolbachia. Our protocol aims to be accessible to newcomers to the field and, although optimized for virus research using Drosophila, some of the techniques could be adapted to other host organisms and/or other microbial pathogens. Preparation of fly stocks requires ∼1 month, virus stock preparation requires 17-20 d, virus injection and survival assays require 10-15 d and virus titration requires 14 d. PMID:26110714

  17. Correlation between Virus Replication and Antibody Responses in Macaques following Infection with Pandemic Influenza A Virus

    PubMed Central

    Koopman, Gerrit; Dekking, Liesbeth; Mortier, Daniëlla; Nieuwenhuis, Ivonne G.; van Heteren, Melanie; Kuipers, Harmjan; Remarque, Edmond J.; Radošević, Katarina; Bogers, Willy M. J. M.

    2015-01-01

    ABSTRACT Influenza virus infection of nonhuman primates is a well-established animal model for studying pathogenesis and for evaluating prophylactic and therapeutic intervention strategies. However, usually a standard dose is used for the infection, and there is no information on the relation between challenge dose and virus replication or the induction of immune responses. Such information is also very scarce for humans and largely confined to evaluation of attenuated virus strains. Here, we have compared the effect of a commonly used dose (4 × 106 50% tissue culture infective doses) versus a 100-fold-higher dose, administered by intrabronchial installation, to two groups of 6 cynomolgus macaques. Animals infected with the high virus dose showed more fever and had higher peak levels of gamma interferon in the blood. However, virus replication in the trachea was not significantly different between the groups, although in 2 out of 6 animals from the high-dose group it was present at higher levels and for a longer duration. The virus-specific antibody response was not significantly different between the groups. However, antibody enzyme-linked immunosorbent assay, virus neutralization, and hemagglutination inhibition antibody titers correlated with cumulative virus production in the trachea. In conclusion, using influenza virus infection in cynomolgus macaques as a model, we demonstrated a relationship between the level of virus production upon infection and induction of functional antibody responses against the virus. IMPORTANCE There is only very limited information on the effect of virus inoculation dose on the level of virus production and the induction of adaptive immune responses in humans or nonhuman primates. We found only a marginal and variable effect of virus dose on virus production in the trachea but a significant effect on body temperature. The induction of functional antibody responses, including virus neutralization titer, hemagglutination inhibition

  18. Cognitive dysfunction and hepatitis C virus infection

    PubMed Central

    Solinas, Antonio; Piras, Maria Rita; Deplano, Angelo

    2015-01-01

    Cognitive dysfunction in patients with chronic hepatitis C virus (HCV) infection is a distinct form of minimal hepatic encephalopathy (MHE). In fact, the majority of HCV-positive patients, irrespective of the grading of liver fibrosis, display alterations of verbal learning, attention, executive function, and memory when they are evaluated by suitable neuropsychological tests. Similarities between the cognitive dysfunction of HCV patients and MHE of patients with different etiologies are unclear. It is also unknown how the metabolic alterations of advanced liver diseases interact with the HCV-induced cognitive dysfunction, and whether these alterations are reversed by antiviral therapies. HCV replication in the brain may play a role in the pathogenesis of neuroinflammation. HCV-related brain dysfunction may be associated with white matter neuronal loss, alterations of association tracts and perfusion. It is unclear to what extent, in patients with cirrhosis, HCV triggers an irreversible neurodegenerative brain damage. New insights on this issue will be provided by longitudinal studies using the protocols established by the diagnostic and statistical manual of mental disorders fifth edition for cognitive disorders. The domains to be evaluated are complex attention; executive functions; learning and memory; perceptual motor functions; social cognition. These evaluations should be associated with fluorodeoxyglucose positron emission tomography and magnetic resonance imaging (MRI) protocols for major cognitive disorders including magnetic resonance spectroscopy, diffusion tensor imaging, magnetic resonance perfusion, and functional MRI. Also, the characteristics of portal hypertension, including the extent of liver blood flow and the type of portal shunts, should be evaluated. PMID:25954475

  19. Monoclonal antibody therapy for Junin virus infection.

    PubMed

    Zeitlin, Larry; Geisbert, Joan B; Deer, Daniel J; Fenton, Karla A; Bohorov, Ognian; Bohorova, Natasha; Goodman, Charles; Kim, Do; Hiatt, Andrew; Pauly, Michael H; Velasco, Jesus; Whaley, Kevin J; Altmann, Friedrich; Gruber, Clemens; Steinkellner, Herta; Honko, Anna N; Kuehne, Ana I; Aman, M Javad; Sahandi, Sara; Enterlein, Sven; Zhan, Xiaoguo; Enria, Delia; Geisbert, Thomas W

    2016-04-19

    Countermeasures against potential biothreat agents remain important to US Homeland Security, and many of these pharmaceuticals could have dual use in the improvement of global public health. Junin virus, the causative agent of Argentine hemorrhagic fever (AHF), is an arenavirus identified as a category A high-priority agent. There are no Food and Drug Administration (FDA) approved drugs available for preventing or treating AHF, and the current treatment option is limited to administration of immune plasma. Whereas immune plasma demonstrates the feasibility of passive immunotherapy, it is limited in quantity, variable in quality, and poses safety risks such as transmission of transfusion-borne diseases. In an effort to develop a monoclonal antibody (mAb)-based alternative to plasma, three previously described neutralizing murine mAbs were expressed as mouse-human chimeric antibodies and evaluated in the guinea pig model of AHF. These mAbs provided 100% protection against lethal challenge when administered 2 d after infection (dpi), and one of them (J199) was capable of providing 100% protection when treatment was initiated 6 dpi and 92% protection when initiated 7 dpi. The efficacy of J199 is superior to that previously described for all other evaluated drugs, and its high potency suggests that mAbs like J199 offer an economical alternative to immune plasma and an effective dual use (bioterrorism/public health) therapeutic. PMID:27044104

  20. Monoclonal antibody therapy for Junin virus infection

    PubMed Central

    Zeitlin, Larry; Geisbert, Joan B.; Deer, Daniel J.; Fenton, Karla A.; Bohorov, Ognian; Bohorova, Natasha; Goodman, Charles; Kim, Do; Hiatt, Andrew; Pauly, Michael H.; Velasco, Jesus; Whaley, Kevin J.; Altmann, Friedrich; Gruber, Clemens; Steinkellner, Herta; Honko, Anna N.; Kuehne, Ana I.; Aman, M. Javad; Sahandi, Sara; Enterlein, Sven; Zhan, Xiaoguo; Enria, Delia; Geisbert, Thomas W.

    2016-01-01

    Countermeasures against potential biothreat agents remain important to US Homeland Security, and many of these pharmaceuticals could have dual use in the improvement of global public health. Junin virus, the causative agent of Argentine hemorrhagic fever (AHF), is an arenavirus identified as a category A high-priority agent. There are no Food and Drug Administration (FDA) approved drugs available for preventing or treating AHF, and the current treatment option is limited to administration of immune plasma. Whereas immune plasma demonstrates the feasibility of passive immunotherapy, it is limited in quantity, variable in quality, and poses safety risks such as transmission of transfusion-borne diseases. In an effort to develop a monoclonal antibody (mAb)-based alternative to plasma, three previously described neutralizing murine mAbs were expressed as mouse-human chimeric antibodies and evaluated in the guinea pig model of AHF. These mAbs provided 100% protection against lethal challenge when administered 2 d after infection (dpi), and one of them (J199) was capable of providing 100% protection when treatment was initiated 6 dpi and 92% protection when initiated 7 dpi. The efficacy of J199 is superior to that previously described for all other evaluated drugs, and its high potency suggests that mAbs like J199 offer an economical alternative to immune plasma and an effective dual use (bioterrorism/public health) therapeutic. PMID:27044104

  1. Infectious salmon anaemia virus (ISAV) mucosal infection in Atlantic salmon.

    PubMed

    Aamelfot, Maria; McBeath, Alastair; Christiansen, Debes H; Matejusova, Iveta; Falk, Knut

    2015-01-01

    All viruses infecting fish must cross the surface mucosal barrier to successfully enter a host. Infectious salmon anaemia virus (ISAV), the causative agent of the economically important infectious salmon anaemia (ISA) in Atlantic salmon, Salmo salar L., has been shown to use the gills as its entry point. However, other entry ports have not been investigated despite the expression of virus receptors on the surface of epithelial cells in the skin, the gastrointestinal (GI) tract and the conjunctiva. Here we investigate the ISAV mucosal infection in Atlantic salmon after experimental immersion (bath) challenge and in farmed fish collected from a confirmed outbreak of ISA in Norway. We show for the first time evidence of early replication in several mucosal surfaces in addition to the gills, including the pectoral fin, skin and GI tract suggesting several potential entry points for the virus. Initially, the infection is localized and primarily infecting epithelial cells, however at later stages it becomes systemic, infecting the endothelial cells lining the circulatory system. Viruses of low and high virulence used in the challenge revealed possible variation in virus progression during infection at the mucosal surfaces. PMID:26490835

  2. Zika virus infections imported from Brazil to Portugal, 2015.

    PubMed

    Zé-Zé, L; Prata, M B; Teixeira, T; Marques, N; Mondragão, A; Fernandes, R; Saraiva da Cunha, J; Alves, M J

    2016-01-01

    Zika virus is an emerging arbovirus transmitted by Aedes sp. mosquitoes like the Dengue and Chikungunya viruses. Zika virus was until recently considered a mild pathogenic mosquito-borne flavivirus with very few reported benign human infections. In 2007, an epidemic in Micronesia initiated the turnover in the epidemiological history of Zika virus and more recently, the potential association with congenital microcephaly cases in Brazil 2015, still under investigation, led the World Health Organization (WHO) to declare a Public Health Emergency of International Concern on February 1, 2016. Here, we present the clinical and laboratory aspects related to the first four imported human cases of Zika virus in Portugal from Brazil, and alert, regarding the high level of traveling between Portugal and Brazil, and the ongoing expansion of this virus in the Americas, for the threat for Zika virus introduction in Europe and the possible introduction to Madeira Island where Aedes aegypti is present. PMID:27134823

  3. Zika virus infections imported from Brazil to Portugal, 2015

    PubMed Central

    Zé-Zé, L.; Prata, M.B.; Teixeira, T.; Marques, N.; Mondragão, A.; Fernandes, R.; Saraiva da Cunha, J.; Alves, M.J.

    2016-01-01

    Zika virus is an emerging arbovirus transmitted by Aedes sp. mosquitoes like the Dengue and Chikungunya viruses. Zika virus was until recently considered a mild pathogenic mosquito-borne flavivirus with very few reported benign human infections. In 2007, an epidemic in Micronesia initiated the turnover in the epidemiological history of Zika virus and more recently, the potential association with congenital microcephaly cases in Brazil 2015, still under investigation, led the World Health Organization (WHO) to declare a Public Health Emergency of International Concern on February 1, 2016. Here, we present the clinical and laboratory aspects related to the first four imported human cases of Zika virus in Portugal from Brazil, and alert, regarding the high level of traveling between Portugal and Brazil, and the ongoing expansion of this virus in the Americas, for the threat for Zika virus introduction in Europe and the possible introduction to Madeira Island where Aedes aegypti is present. PMID:27134823

  4. First case of imported Zika virus infection in Spain.

    PubMed

    Bachiller-Luque, Pablo; Domínguez-Gil González, Marta; Álvarez-Manzanares, Jesús; Vázquez, Ana; De Ory, Fernando; Sánchez-Seco Fariñas, M Paz

    2016-04-01

    We report a case of Zika virus (ZIKV) infection in a patient with diarrhea, fever, synovitis, non-purulent conjunctivitis, and with discreet retro-orbital pain, after returning from Colombia in January 2016. The patient referred several mosquito bites. Presence of ZIKV was detected by PCR (polymerase chain reaction) in plasma. Rapid microbiological diagnosis of ZIKV infection is needed in European countries with circulation of its vector, in order to avoid autochthonous circulation. The recent association of ZIKV infection with abortion and microcephaly, and a Guillain-Barré syndrome highlights the need for laboratory differentiation of ZIKV from other virus infection. Women with potential risk for Zika virus infection who are pregnant or planning to become pregnant must mention that fact during prenatal visits in order to be evaluated and properly monitored. PMID:26994814

  5. Infection of Mosquito Cells (C6/36) by Dengue-2 Virus Interferes with Subsequent Infection by Yellow Fever Virus.

    PubMed

    Abrao, Emiliana Pereira; da Fonseca, Benedito Antônio Lopes

    2016-02-01

    Dengue is one of the most important diseases caused by arboviruses in the world. Yellow fever is another arthropod-borne disease of great importance to public health that is endemic to tropical regions of Africa and the Americas. Both yellow fever and dengue viruses are flaviviruses transmitted by Aedes aegypti mosquitoes, and then, it is reasonable to consider that in a given moment, mosquito cells could be coinfected by both viruses. Therefore, we decided to evaluate if sequential infections of dengue and yellow fever viruses (and vice-versa) in mosquito cells could affect the virus replication patterns. Using immunofluorescence and real-time PCR-based replication assays in Aedes albopictus C6/36 cells with single or sequential infections with both viruses, we demonstrated the occurrence of viral interference, also called superinfection exclusion, between these two viruses. Our results show that this interference pattern is particularly evident when cells were first infected with dengue virus and subsequently with yellow fever virus (YFV). Reduction in dengue virus replication, although to a lower extent, was also observed when C6/36 cells were initially infected with YFV followed by dengue virus infection. Although the importance that these findings have on nature is unknown, this study provides evidence, at the cellular level, of the occurrence of replication interference between dengue and yellow fever viruses and raises the question if superinfection exclusion could be a possible explanation, at least partially, for the reported lack of urban yellow fever occurrence in regions where a high level of dengue transmission occurs. PMID:26808727

  6. Effect of Cell Physiological State on Infection by Rat Virus

    PubMed Central

    Tennant, Raymond W.; Layman, Kenneth R.; Hand, Russell E.

    1969-01-01

    Infection by rat virus has been studied in cultures of rat embryo cells to evaluate the Margolis-Kilham hypothesis that the virus preferentially infects tissues with actively dividing cells. An enhancement of infection was seen in cultures infected 10 hr after fresh medium was added as compared to infection of stationary cultures (infected before addition of fresh medium). Since addition of fresh medium stimulates deoxyribonucleic acid (DNA) synthesis, the number of cells per culture synthesizing DNA at the time of infection was compared with the proportion of cells which synthesized viral protein. Cells were infected before the medium change and 10 or 24 hr after the medium change and were pulse-labeled with 3H-thymidine at the time virus was added. The cells were allowed to initiate viral protein synthesis before they were fixed and stained with fluorescein-conjugated anti-rat virus serum. Fluorescence microscopy permitted both labels to be counted simultaneouly and showed that the greatest proportion of cells synthesizing viral protein were those which had incorporated 3H-thymidine at the time of infection. Images PMID:16789120

  7. Experimental co-infection studies with avian influenza viruses and Newcastle Disease viruses in chickens, turkeys and domestic ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Co-infections of poultry with Newcastle Disease viruses (NDVs) and Avian Influenza viruses (AIVs) present a problem both from the clinical point of view and the diagnosis of these viruses. Little has been done to understand the interactions between these two viruses when infecting poultry. Exposur...

  8. Co-infection and disease severity of Ohio Maize dwarf mosaic virus and Maize chlorotic dwarf virus strains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two major maize viruses have been reported in the United States: Maize dwarf mosaic virus (MDMV) and Maize chlorotic dwarf virus (MCDV). These viruses co-occur in regions where maize is grown such that co-infections are likely. Co-infection of different strains of MCDV is also observed frequently...

  9. Senescence affects endothelial cells susceptibility to dengue virus infection.

    PubMed

    AbuBakar, Sazaly; Shu, Meng-Hooi; Johari, Jefree; Wong, Pooi-Fong

    2014-01-01

    Alteration in the endothelium leading to increased vascular permeability contributes to plasma leakage seen in dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). An earlier study showed that senescent endothelial cells (ECs) altered the ECs permeability. Here we investigated the susceptibility of senescing human umbilical vein endothelial cells (HUVECs) to dengue virus infection and determined if dengue virus infection induces HUVECs senescence. Our results suggest that DENV type-2 (DENV-2) foci forming unit (FFU) and extracellular virus RNA copy number were reduced by at least 35% and 85% in infection of the intermediate young and early senescent HUVECs, respectively, in comparison to infection of young HUVECs. No to low infectivity was recovered from infection of late senescent HUVECs. DENV infection also increases the percentage of HUVECs expressing senescence-associated (SA)-β-gal, cells arrested at the G2/M phase or 4N DNA content stage and cells with enlarged morphology, indicative of senescing cells. Alteration of HUVECs morphology was recorded using impedance-based real-time cell analysis system following DENV-2 infection. These results suggest that senescing HUVECs do not support DENV infection and DENV infection induces HUVECs senescence. The finding highlights the possible role of induction of senescence in DENV infection of the endothelial cells. PMID:24782642

  10. Reduced Risk of Disease During Postsecondary Dengue Virus Infections

    PubMed Central

    Olkowski, Sandra; Forshey, Brett M.; Morrison, Amy C.; Rocha, Claudio; Vilcarromero, Stalin; Halsey, Eric S.; Kochel, Tadeusz J.; Scott, Thomas W.; Stoddard, Steven T.

    2013-01-01

    Background. Antibodies induced by infection with any 1 of 4 dengue virus (DENV) serotypes (DENV-1–4) may influence the clinical outcome of subsequent heterologous infections. To quantify potential cross-protective effects, we estimated disease risk as a function of DENV infection, using data from longitudinal studies performed from September 2006 through February 2011 in Iquitos, Peru, during periods of DENV-3 and DENV-4 transmission. Methods. DENV infections before and during the study period were determined by analysis of serial serum samples with virus neutralization tests. Third and fourth infections were classified as postsecondary infections. Dengue fever cases were detected by door-to-door surveillance for acute febrile illness. Results. Among susceptible participants, 39% (420/1077) and 53% (1595/2997) seroconverted to DENV-3 and DENV-4, respectively. Disease was detected in 7% of DENV-3 infections and 10% of DENV-4 infections. Disease during postsecondary infections was reduced by 93% for DENV-3 and 64% for DENV-4, compared with primary and secondary infections. Despite lower disease rates, postsecondary infections constituted a significant proportion of apparent infections (14% [for DENV-3 infections], 45% [for DENV-4 infections]). Conclusions. Preexisting heterotypic antibodies markedly reduced but did not eliminate the risk of disease in this study population. These results improve understanding of how preinfection history can be associated with dengue outcomes and DENV transmission dynamics. PMID:23776195

  11. Drosophila C Virus Systemic Infection Leads to Intestinal Obstruction

    PubMed Central

    Chtarbanova, Stanislava; Lamiable, Olivier; Lee, Kwang-Zin; Galiana, Delphine; Troxler, Laurent; Meignin, Carine; Hetru, Charles; Hoffmann, Jules A.; Daeffler, Laurent

    2014-01-01

    ABSTRACT Drosophila C virus (DCV) is a positive-sense RNA virus belonging to the Dicistroviridae family. This natural pathogen of the model organism Drosophila melanogaster is commonly used to investigate antiviral host defense in flies, which involves both RNA interference and inducible responses. Although lethality is used routinely as a readout for the efficiency of the antiviral immune response in these studies, virus-induced pathologies in flies still are poorly understood. Here, we characterize the pathogenesis associated with systemic DCV infection. Comparison of the transcriptome of flies infected with DCV or two other positive-sense RNA viruses, Flock House virus and Sindbis virus, reveals that DCV infection, unlike those of the other two viruses, represses the expression of a large number of genes. Several of these genes are expressed specifically in the midgut and also are repressed by starvation. We show that systemic DCV infection triggers a nutritional stress in Drosophila which results from intestinal obstruction with the accumulation of peritrophic matrix at the entry of the midgut and the accumulation of the food ingested in the crop, a blind muscular food storage organ. The related virus cricket paralysis virus (CrPV), which efficiently grows in Drosophila, does not trigger this pathology. We show that DCV, but not CrPV, infects the smooth muscles surrounding the crop, causing extensive cytopathology and strongly reducing the rate of contractions. We conclude that the pathogenesis associated with systemic DCV infection results from the tropism of the virus for an important organ within the foregut of dipteran insects, the crop. IMPORTANCE DCV is one of the few identified natural viral pathogens affecting the model organism Drosophila melanogaster. As such, it is an important virus for the deciphering of host-virus interactions in insects. We characterize here the pathogenesis associated with DCV infection in flies and show that it results from the

  12. Chronic West Nile virus infection in kea (Nestor notabilis).

    PubMed

    Bakonyi, Tamás; Gajdon, Gyula K; Schwing, Raoul; Vogl, Wolfgang; Häbich, Annett-Carolin; Thaller, Denise; Weissenböck, Herbert; Rudolf, Ivo; Hubálek, Zdenek; Nowotny, Norbert

    2016-02-01

    Six kea (Nestor notabilis) in human care, naturally infected with West Nile virus (WNV) lineage 2 in Vienna, Austria, in 2008, developed mild to fatal neurological signs. WNV RNA persisted and the virus evolved in the birds' brains, as demonstrated by (phylo)genetic analyses of the complete viral genomes detected in kea euthanized between 2009 and 2014. WNV antibodies persisted in the birds, too. Chronic WNV infection in the brain might contribute to the circulation of the virus through oral transmission to predatory birds. PMID:26790946

  13. Natural infection of turkeys by infectious laryngotracheitis virus.

    PubMed

    Portz, Cristiana; Beltrão, Nilzane; Furian, Thales Quedi; Júnior, Alfredo Bianco; Macagnan, Marisa; Griebeler, Josiane; Lima Rosa, Carlos André Veiga; Colodel, Edson Moleta; Driemeier, David; Back, Alberto; Barth Schatzmayr, Ortrud Monika; Canal, Cláudio Wageck

    2008-09-18

    The infectious laryngotracheitis virus (ILTV) is an important respiratory pathogen of chickens that also infects pheasants and peafowl. Epidemiologically non-related commercial turkey flocks with clinical signs such as tracheitis, swollen sinuses, conjunctivitis and expectoration of bloody mucus were examined for the presence of the virus. Laboratory ILTV detection was performed by virus isolation in embryonated eggs and cell cultures, PCR and sequencing of amplification products, histopathology, indirect immunofluorescence and electron microscopy. One ILTV turkey isolate was also experimentally inoculated into susceptible chickens and turkeys, reproducing a mild respiratory disease. This is the first description of natural infections with ILTV in turkeys. PMID:18436397

  14. Characteristics of mild dengue virus infection in Thai children.

    PubMed

    Yoon, In-Kyu; Srikiatkhachorn, Anon; Hermann, Laura; Buddhari, Darunee; Scott, Thomas W; Jarman, Richard G; Aldstadt, Jared; Nisalak, Ananda; Thammapalo, Suwich; Bhoomiboonchoo, Piraya; Mammen, Mammen P; Green, Sharone; Gibbons, Robert V; Endy, Timothy P; Rothman, Alan L

    2013-12-01

    A four-year longitudinal cohort and geographic cluster study in rural Thailand was conducted to characterize the clinical spectrum of dengue virus (DENV) infection. Symptomatic DENV infections in the cohort were detected by active school absence-based surveillance that triggered cluster investigations around ill cohort children. Data from 189 cohort children with symptomatic DENV infection and 126 contact children in the clusters with DENV infection were analyzed. Of infected contacts, only 19% were asymptomatic; 81% were symptomatic, but only 65.9% reported fever. Symptom-based case definitions were unreliable for diagnosis. Symptomatic infections in contacts were milder with lower DENV RNA levels than the cohort. Infections in contacts with fever history were more likely to have detectable DENV RNA than infections without fever history. Mild infections identified by cluster investigations account for a major proportion of all DENV infections. These findings are relevant for disease burden assessments, transmission modeling, and determination of vaccine impact. PMID:24127167

  15. The Aedes aegypti Toll Pathway Controls Dengue Virus Infection

    PubMed Central

    Xi, Zhiyong; Ramirez, Jose L.; Dimopoulos, George

    2008-01-01

    Aedes aegypti, the mosquito vector of dengue viruses, utilizes its innate immune system to ward off a variety of pathogens, some of which can cause disease in humans. To date, the features of insects' innate immune defenses against viruses have mainly been studied in the fruit fly Drosophila melanogaster, which appears to utilize different immune pathways against different types of viruses, in addition to an RNA interference–based defense system. We have used the recently released whole-genome sequence of the Ae. aegypti mosquito, in combination with high-throughput gene expression and RNA interference (RNAi)-based reverse genetic analyses, to characterize its response to dengue virus infection in different body compartments. We have further addressed the impact of the mosquito's endogenous microbial flora on virus infection. Our findings indicate a significant role for the Toll pathway in regulating resistance to dengue virus, as indicated by an infection-responsive regulation and functional assessment of several Toll pathway–associated genes. We have also shown that the mosquito's natural microbiota play a role in modulating the dengue virus infection, possibly through basal-level stimulation of the Toll immune pathway. PMID:18604274

  16. [Border disease: a persistent virus infection in sheep (author's transl)].

    PubMed

    Terpstra, C

    1980-08-15

    Border disease (BD) is a congenital infection of sheep characterised by still-birth, abortion and the birth of weak lambs with nervous symptoms and sometimes an abnormally hairy birthcoat. The lambs are almost constantly trembling or shaking, they often have an erratic gait and in severe cases are unable to rise. The nervous signs are due to a defective myelinogensis of the central nervous system and tend to disappear at a later age. Many affected lambs die shortly after birth and those which survive usually show retarded growth. The disease is caused by a virus which is closely related to the virus of bovine virus diarrhoea (BVD). The virus may be isolated from every organ and is excreted with saliva, nasal discharge, urine and faeces. Clinically the diagnosis can be made with high probability when nervous signs and hairy birthcoat are both present. Laboratory diagnosis is based on the detection of antigen by immunofluorescence or virus isolation. In addition ewes of BD-affected lambs usually possess antibodies against BVD-virus. In some lambs, an immune response starts during prenatal life, others show a transient or lasting low level response at a later age, whereas still others remained serologically negative for at least 2 1/2 years. Asymptomatic virus carriers occur among lambs as well as among adult sheep. The persistently infected animals are continously shedding virus and thus maintain the infection in the flock. PMID:6252652

  17. Respiratory Syncytial Virus Infection (RSV): Infection and Incidence

    MedlinePlus

    ... Links Unexplained Respiratory Disease Outbreaks Red Book® Online Infection and Incidence Recommend on Facebook Tweet Share Compartir RSV can cause upper respiratory infections (such as colds) and lower respiratory tract infections ( ...

  18. Occurrence of viruses infecting pea in Iran.

    PubMed

    Esfandiari, N; Kohi-Habibi, M; Mosahebi, Gh

    2006-01-01

    A survey was conducted to determine the incidence of Alfalfa mosaic virus (AMV), Bean yellow mosaic virus (BYMV), Broad bean wilt virus-1 (BBWV), Pea leafroll virus (PLRV), Pea enation mosaic virus (PEMV), Pea seed borne mosaic virus (PSbMV), Potato virus x(PVX), Tomato mosaic virus (ToMV), Tomato spotted wilt virus (TSWV) on pea (Pisum sativum) in Iran. A Total of 1276 random and 684 symptomatic pea samples were collected during the spring and summer of 2002-2004 in Tehran province of Iran, where pea is grown, and tested by enzyme-linked immunosorbent assay (ELISA) using specific polyclonal antibodies. Serological diagnoses were confirmed by electron microscopy and host range studies. Incidence of viruses in decreasing order was PVX (69%), ToMV (59%), PSbMV (36.6%), BBWV-1 (26.1%), BYMV (20.3%), AMV (17.77%), TSWV (12.6%), PEMV (10.9%), PLRV (6.78%). In this survey, natural occurrence of AMV, BBWV-1, PSbMV, TSWV, PVX and ToMV was reported for the first time on the pea in Iran. PMID:17390891

  19. Immunity to Polyomavirus Infection: The Polyoma Virus-Mouse Model

    PubMed Central

    Swanson, Phillip A.; Lukacher, Aron E.; Szomolanyi-Tsuda, Eva

    2009-01-01

    A ubiquitous clinically silent murine pathogen, polyoma virus has enjoyed long-term co-evolution with the mouse, a highly tractable and genetically and immunologically informative small animal model. Thus, polyoma virus has provided a valuable experimental construct to decipher the host immune mechanisms that come into play to control systemic low-level persistent viral infections. Impaired immunosurveillance for infected cells puts the murine host at risk both to injury resulting from excessive direct virus cytolysis and development of virus-induced tumors. In this review, we present our current understanding of the multifaceted immune response invoked by the mouse to maintain détente with this potentially deleterious persistent natural pathogen, and discuss implications of these studies for therapeutic interventions for human polyomavirus infection. PMID:19505652

  20. Zika Virus Infection and Development of a Murine Model.

    PubMed

    Shah, Ankit; Kumar, Anil

    2016-08-01

    In view of the recent outbreak of Zika virus (ZIKV), there is an urgent need to investigate the pathogenesis of the symptoms associated with ZIKV infection. Since the first identification of the virus in 1947, the pathologies associated with ZIKV infection were thought to be limited with mild illness that presented fever, rashes, muscle aches, and weakness. However, ZIKV infection has been shown to cause Guillain-Barré Syndrome, and numerous cases of congenital microcephaly in children have been reported when pregnant females were exposed to the virus. The severity and the rate of spread of ZIKV in the last year has drawn alarming interest among researchers to investigate murine models to study viral pathogenesis and develop candidate vaccines. A recent study by Lazear and colleagues, in the May 2016 issue of cell host and microbe, is an effort to study the pathogenesis of contemporary and historical virus strains in various mouse models. PMID:27260223

  1. Intrauterine herpes simplex virus infection presenting with hypopigmented lesions.

    PubMed

    Low, Lynette C M; Carton, James; Walker, Marjorie; Tudor-Williams, Gareth; Hardman, Catherine

    2012-01-01

    Genital herpes simplex virus (HSV) is a sexually transmitted infection that can be transmitted from mother to child in utero, perinatally, or postnatally. Cutaneous infection with HSV commonly presents as vesicles affecting the skin, eyes, or mouth. In our case, we report a well child with cutaneous hypopigmented patches at birth that preceded typical blistering. PMID:22010816

  2. Heart and Skeletal Muscle Are Targets of Dengue Virus Infection

    PubMed Central

    Salgado, Doris Martha; Eltit, José Miguel; Mansfield, Keith; Panqueba, César; Castro, Dolly; Vega, Martha Rocio; Xhaja, Kris; Schmidt, Diane; Martin, Katherine J.; Allen, Paul D.; Rodriguez, Jairo Antonio; Dinsmore, Jonathan H.; López, José Rafael; Bosch, Irene

    2010-01-01

    Background Dengue fever is one of the most significant re-emerging tropical diseases, despite our expanding knowledge of the disease, viral tropism is still not known to target heart tissues or muscle. Methods A prospective pediatric clinical cohort of 102 dengue hemorrhagic fever patients from Colombia, South America, was followed for 1 year. Clinical diagnosis of myocarditis was routinely performed. Electrocardiograph and echocardiograph analysis were performed to confirm those cases. Immunohistochemistry for detection of dengue virus and inflammatory markers was performed on autopsied heart tissue. In vitro studies of human striated skeletal fibers (myotubes) infected with dengue virus were used as a model for myocyte infection. Measurements of intracellular Ca2+ concentration as well as immunodetection of dengue virus and inflammation markers in infected myotubes were performed. Results Eleven children with dengue hemorrhagic fever presented with symptoms of myocarditis. Widespread viral infection of the heart, myocardial endothelium, and cardiomyocytes, accompanied by inflammation was observed in 1 fatal case. Immunofluorescence confocal microscopy showed that myotubes were infected by dengue virus and had increased expression of the inflammatory genes and protein IP-10. The infected myotubes also had increases in intracellular Ca2+ concentration. Conclusions Vigorous infection of heart tissues in vivo and striated skeletal cells in vitro are demonstrated. Derangements of Ca2+ storage in the infected cells may directly contribute to the presentation of myocarditis in pediatric patients. PMID:20032806

  3. Clinical bovine viral diarrhoea virus infection in Jordan.

    PubMed

    Abutarbush, S M; Alqawasmeh, D M

    2010-12-01

    A 1-year-old Holstein Friesian heifer was presented for anorexia and acute diarrhoea. The heifer was born and raised at the farm. Bovine viral diarrhoea virus (BVDV) infection was diagnosed using clinical signs and RT-PCR. Clinical BVDV infection has never been reported in Jordan. PMID:21117287

  4. Evidence of Apis cerana sacbrood virus infection in Apis mellifera

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sacbrood virus (SBV) is one of the most serious threats to Apis cerana but is much less destructive to Apis mellifera. In previous studies, SBV isolates infecting A. cerana and A. mellifera were identified as different serotypes, suggesting a species-barrier of SBV infection. In order to clarify whe...

  5. ZIKA VIRUS INFECTION; VERTICAL TRANSMISSION AND FOETAL CONGENITAL ANOMALIES.

    PubMed

    Abbasi, Aziz-un-Nisa

    2016-01-01

    Zika virus (ZIKV) is an arbovirus belonging to flaviviridae family that includes Dengue, West Nile, and Yellow Fever among others. Zika virus was first discovered in 1947 in Zika forest of Uganda. It is a vector borne disease, which has been sporadically reported mostly from Africa, Pacific islands and Southeast Asia since its discovery. ZIKV infection presents as a mild illness with symptoms lasting for several days to a week after the bite of an infected mosquito. Majority of the patients have low grade fever, rash, headaches, joints pain, myalgia, and flu like symptoms. Pregnant women are more vulnerable to ZIKV infection and serious congenital anomalies can occur in foetus through trans-placental transmission. The gestation at which infection is acquired is important. Zika virus infection acquired in early pregnancy poses greater risk. There is no evidence so far about transmission through breast milk. Foetal microcephaly, Gillian Barre syndrome and other neurological and autoimmune syndromes have been reported in areas where Zika outbreaks have occurred. As infection is usually very mild no specific treatment is required. Pregnant women may be advised to take rest, get plenty of fluids. For fever and pain they can take antipyretics like paracetamol. So far no specific drugs or vaccines are available against Zika Virus Infection so prevention is the mainstay against this diseases. As ZIKV infection is a vector borne disease, prevention can be a multi-pronged strategy. These entail vector control interventions, personal protection, environmental sanitation and health education among others. PMID:27323550

  6. [Dementia and human inmmunodeficiency virus infection].

    PubMed

    Gray, F

    1998-01-01

    HIV-associated neurological manifestations: dementia, myelopathy, and neuropathy, have become one of the commonest causes of neurological disorders in young people. Cognitive impairment develops in about 30 p. 100 of patients with AIDS and frank dementia in 15 to 20 p. 100 with an annual incidence after AIDS of approximatively 7 p. 100. Typically, the onset of dementia is relatively abrupt over a few weeks or months. The clinical manifestations of the encephalopathy now termed "HIV-dementia", suggest predominant subcortical or frontal involvement. Typical presentation includes apathy and inertia, memory loss and cognitive slowing, minor depressive symptoms and withdrawal from usual activities. Neurological examination may show hypertonia of lower limbs, tremor, clonus, frontal release signs and hyperactive reflexes. Terminally, the patient is bedbound, incontinent, abulic or mute with decorticate posturing leading to death over 3 to 6 months. However, a stabilisation and even a regression of the cognitive disorders have been observed following antiretroviral treatment. Radiological features of HIV dementia include both central and cortical atrophy and white matter rarefaction. However they are neither invariable nor specific. Together with CSF examination, they are more important to exclude opportunistic infections. Indeed, although a completely normal CSF profile may reasonably exclude the diagnosis; at present, no single test or combination of tests can reliably diagnose HIV dementia. Although the clinical characteristics of HIV-dementia are now clearly established, its pathogenesis is unclear and its pathological counterpart remains a matter of debate. A number of "HIV-induced" lesions may be found in the brain of AIDS patients and their causative role in HIV-dementia has been considered. They include HIV encephalitis due to productive CNS infection by the virus, diffuse white matter pallor "HIV-leukoencephalopathy" reflecting an abnormality of the blood brain

  7. Chemokine antagonism in chronic hepatitis C virus infection.

    PubMed

    Charles, Edgar D; Dustin, Lynn B

    2011-01-01

    Immune responses to hepatitis C virus (HCV) fail to clear the virus in most individuals. Why patients who are less likely to clear HCV infection have high plasma levels of CXCL10 (also known as IP-10), a chemokine that directs T cells to sites of infection, has long been unclear. In this issue of the JCI, Casrouge and colleagues shed light on this paradox by showing that CXCL10 in the plasma of many HCV patients is enzymatically processed to produce a CXCL10 receptor antagonist. These findings introduce a role for chemokine antagonism during HCV infection and unveil new avenues for improved HCV diagnosis and therapy. PMID:21183783

  8. Autophagy Stimulation Abrogates Herpes simplex Virus-1 Infection

    PubMed Central

    Yakoub, Abraam M.; Shukla, Deepak

    2015-01-01

    Herpes simplex virus-1 (HSV-1) is a double-stranded DNA virus that causes life-long infections. HSV-1 infections may lead to herpetic stromal keratitis that may advance to corneal blindness. HSV-1 infections can also cause fatal conditions, such as herpes encephalitis, or neonatal disease. A major virulence mechanism of HSV-1 is the control of autophagy, an innate immune defense strategy that could otherwise degrade viral particles. Here, to investigate a new mechanism for antiviral therapy, we tested the effect of various autophagy inducers (physiological and pharmacological) on infection. Autophagy stimulation was confirmed to significantly suppress HSV-1 infection in various cell types, without affecting cell viability. This study establishes the importance of autophagy for regulating HSV-1 infection, and provides a proof-of-principle evidence for a novel antiviral mechanism. PMID:25856282

  9. Virus enrichment for single virus infection by using 3D insulator based dielectrophoresis.

    PubMed

    Masuda, Taisuke; Maruyama, Hisataka; Honda, Ayae; Arai, Fumihito

    2014-01-01

    We developed an active virus filter (AVF) that enables virus enrichment for single virus infection, by using insulator-based dielectrophoresis (iDEP). A 3D-constricted flow channel design enabled the production of an iDEP force in the microfluidic chip. iDEP using a chip with multiple active virus filters (AVFs) was more accurate and faster than using a chip with a single AVF, and improved the efficiency of virus trapping. We utilized maskless photolithography to achieve the precise 3D gray-scale exposure required for fabrication of constricted flow channel. Influenza virus (A PR/8) was enriched by a negative DEP force when sinusoidal wave was applied to the electrodes within an amplitude range of 20 Vp-p and a frequency of 10 MHz. AVF-mediated virus enrichment can be repeated simply by turning the current ON or OFF. Furthermore, the negative AVF can inhibit virus adhesion onto the glass substrate. We then trapped and transported one of the enriched viruses by using optical tweezers. This microfluidic chip facilitated the effective transport of a single virus from AVFs towards the cell-containing chamber without crossing an electrode. We successfully transported the virus to the cell chamber (v = 10 µm/s) and brought it infected with a selected single H292 cell. PMID:24918921

  10. Interleukin-3 protects mice from acute herpes simplex virus infection.

    PubMed Central

    Chan, W L; Ziltener, H J; Liew, F Y

    1990-01-01

    Evidence presented here from kinetic studies of interleukin-3 (IL-3) production by spleen cells from adult mice infected subcutaneously with HSV-1 and stimulated with virus antigen in vitro shows that high levels of IL-3 were produced at the onset of the animal's recovery from the disease state. Injections of anti-IL-3 antibody into HSV-1-infected mice resulted in exacerbation of the disease. Primary mouse embryonic head cells grown in the presence of murine IL-3, when infected with HSV-1, showed a 1000-fold decrease in virus titre compared with untreated control cells. This inhibiting effect was reversed by anti-IL-3 and anti-IFN-alpha, beta and gamma antibodies. These data suggest that IL-3 plays a host-protective role against HSV infection and it does so probably by inducing brain cells to produce interferons which then inhibit virus replication. PMID:2176641

  11. Immunofluorescence studies of disseminated Hantaan virus infection of suckling mice.

    PubMed Central

    Kurata, T; Tsai, T F; Bauer, S P; McCormick, J B

    1983-01-01

    Hantaan virus, the etiological agent of Korean hemorrhagic fever, was inoculated intracerebrally or intraperitoneally into suckling mice, and the course of the infection was followed by infectivity titration and immunofluorescence studies. Mice became ill and were moribund by 13 to 14 days postinfection. In mice inoculated either intracerebrally or intraperitoneally, virus antigen was present in brain, heart, lungs, liver, and kidney. Less consistently, specific fluorescence was observed in spleen, pituitary gland, thymus, lymph nodes, adrenal, pancreas, salivary glands, trigeminal ganglia, adipose tissue, intestine, and muscle. In all of these tissues, the primary target of infection was the capillary endothelium. In mice inoculated intracerebrally, virus antigen was present mainly in choroid plexus, hippocampal nuclei, and meninges, but in mice inoculated intraperitoneally, central nervous system infection was marked by antigen accumulation in cortical nuclei and thalamus. Images PMID:6134678

  12. Domestic Pigs Are Susceptible to Infection with Influenza B Viruses

    PubMed Central

    Ran, Zhiguang; Shen, Huigang; Lang, Yuekun; Kolb, Elizabeth A.; Turan, Nuri; Zhu, Laihua; Ma, Jingjiao; Bawa, Bhupinder; Liu, Qinfang; Liu, Haixia; Quast, Megan; Sexton, Gabriel; Krammer, Florian; Hause, Ben M.; Christopher-Hennings, Jane; Nelson, Eric A.; Richt, Juergen

    2015-01-01

    ABSTRACT Influenza B virus (IBV) causes seasonal epidemics in humans. Although IBV has been isolated from seals, humans are considered the primary host and reservoir of this important pathogen. It is unclear whether other animal species can support the replication of IBV and serve as a reservoir. Swine are naturally infected with both influenza A and C viruses. To determine the susceptibility of pigs to IBV infection, we conducted a serological survey for U.S. Midwest domestic swine herds from 2010 to 2012. Results of this study showed that antibodies to IBVs were detected in 38.5% (20/52) of sampled farms, and 7.3% (41/560) of tested swine serum samples were positive for IBV antibodies. Furthermore, swine herds infected with porcine reproductive and respiratory syndrome virus (PRRSV) showed a higher prevalence of IBV antibodies in our 2014 survey. In addition, IBV was detected in 3 nasal swabs collected from PRRSV-seropositive pigs by real-time RT-PCR and sequencing. Finally, an experimental infection in pigs, via intranasal and intratracheal routes, was performed using one representative virus from each of the two genetically and antigenically distinct lineages of IBVs: B/Brisbane/60/2008 (Victoria lineage) and B/Yamagata/16/1988 (Yamagata lineage). Pigs developed influenza-like symptoms and lung lesions, and they seroconverted after virus inoculation. Pigs infected with B/Brisbane/60/2008 virus successfully transmitted the virus to sentinel animals. Taken together, our data demonstrate that pigs are susceptible to IBV infection; therefore, they warrant further surveillance and investigation of swine as a potential host for human IBV. IMPORTANCE IBV is an important human pathogen, but its ability to infect other species, for example, pigs, is not well understood. We showed serological evidence that antibodies to two genetically and antigenically distinct lineages of IBVs were present among domestic pigs, especially in swine herds previously infected with PRRSV

  13. Multiple Epstein-Barr virus infections in healthy individuals

    NASA Technical Reports Server (NTRS)

    Walling, Dennis M.; Brown, Abigail L.; Etienne, Wiguins; Keitel, Wendy A.; Ling, Paul D.; Butel, J. S. (Principal Investigator)

    2003-01-01

    We employed a newly developed genotyping technique with direct representational detection of LMP-1 gene sequences to study the molecular epidemiology of Epstein-Barr virus (EBV) infection in healthy individuals. Infections with up to five different EBV genotypes were found in two of nine individuals studied. These results support the hypothesis that multiple EBV infections of healthy individuals are common. The implications for the development of an EBV vaccine are discussed.

  14. Vaccination of chimpanzees against infection by the hepatitis C virus.

    PubMed Central

    Choo, Q L; Kuo, G; Ralston, R; Weiner, A; Chien, D; Van Nest, G; Han, J; Berger, K; Thudium, K; Kuo, C

    1994-01-01

    A high incidence of community-acquired hepatitis C virus infection that can lead to the progressive development of chronic active hepatitis, liver cirrhosis, and primary hepatocellular carcinoma occurs throughout the world. A vaccine to control the spread of this agent that represents a major cause of chronic liver disease is therefore needed. Seven chimpanzees (Pan troglodytes) have been immunized with both putative envelope glycoproteins [E1 (gp33) and E2 (gp72)] that were copurified from HeLa cells infected with a recombinant vaccinia virus expression vector. Despite the induction of a weak humoral immune response to these viral glycoproteins in experimentally infected chimpanzees, a strong humoral immune response was obtained in all vaccines. The five highest responders showed complete protection against an i.v. challenge with homologous hepatitis C virus 1. The remaining two vaccines became infected, but both infection and disease may have been ameliorated in comparison with four similarly challenged control chimpanzees, all of which developed acute hepatitis and chronic infections. These results provide considerable encouragement for the eventual control of hepatitis C virus infection by vaccination. PMID:7509068

  15. Vaccination of chimpanzees against infection by the hepatitis C virus.

    PubMed

    Choo, Q L; Kuo, G; Ralston, R; Weiner, A; Chien, D; Van Nest, G; Han, J; Berger, K; Thudium, K; Kuo, C

    1994-02-15

    A high incidence of community-acquired hepatitis C virus infection that can lead to the progressive development of chronic active hepatitis, liver cirrhosis, and primary hepatocellular carcinoma occurs throughout the world. A vaccine to control the spread of this agent that represents a major cause of chronic liver disease is therefore needed. Seven chimpanzees (Pan troglodytes) have been immunized with both putative envelope glycoproteins [E1 (gp33) and E2 (gp72)] that were copurified from HeLa cells infected with a recombinant vaccinia virus expression vector. Despite the induction of a weak humoral immune response to these viral glycoproteins in experimentally infected chimpanzees, a strong humoral immune response was obtained in all vaccines. The five highest responders showed complete protection against an i.v. challenge with homologous hepatitis C virus 1. The remaining two vaccines became infected, but both infection and disease may have been ameliorated in comparison with four similarly challenged control chimpanzees, all of which developed acute hepatitis and chronic infections. These results provide considerable encouragement for the eventual control of hepatitis C virus infection by vaccination. PMID:7509068

  16. Why Zika virus infection has become a public health concern?

    PubMed

    Chen, Hui-Lan; Tang, Ren-Bin

    2016-04-01

    Prior to 2015, Zika Virus (ZIKV) outbreaks had occurred in areas of Africa, Southeast Asia, and the Pacific Islands. Although a causal relationship between Zika infection during pregnancy and microcephaly is strongly suspected, such a connection has not yet been scientifically proven. In May 2015, the outbreak of ZIKV infection in Brazil led to reports of syndrome and pregnant women giving birth to babies with birth defects and poor pregnancy outcomes; the Pan American Health Organization (PAHO) issued an alert regarding the first confirmed ZIKV infection in Brazil. Currently, ZIKV outbreaks are ongoing and it will be difficult to predict how the virus will spread over time. ZIKV is transmitted to humans primarily through the bite of infected mosquitos, Aedes aegypti and Aedes albopictus. These mosquitoes are the principle vectors of dengue, and ZIKV disease generally is reported to include symptoms associated with acute febrile illnesses that clinically resembles dengue fever. The laboratory diagnosis can be performed by using reverse-transcriptase polymerase chain reaction (RT-PCR) on serum, viral nucleic acid and virus-specific immunoglobulin M. There is currently no vaccine and antiviral treatment available for ZIKV infection, and the only way to prevent congenital ZIKV infection is to prevent maternal infection. In February 2016, the Taiwan Centers for Disease Control (Taiwan CDC) activated ZIKV as a Category V Notifiable Infectious Disease similar to Ebola virus disease and MERS. PMID:27052792

  17. Metabolic stress in infected cells may represent a therapeutic target for human immunodeficiency virus infection.

    PubMed

    Alonso-Villaverde, Carlos; Menéndez, Javier A; Joven, Jorge

    2013-07-01

    Worldwide, there are thousands of new cases of human immunodeficiency virus-1 (HIV-1) infection per day. The effectiveness of current combination antiretroviral therapy (ART) is relative; to prioritize finding vaccines and/or cure-oriented initiatives should be reinforced because there is little room, if any, for procrastination. Basic and clinical findings on HIV-1 reservoirs suggest that disruption of virus latency is feasible. Because the goal is curing HIV-1 infection, we should be aware that the challenge is to eradicate the viruses of every single infected cell and consequently acting upon virus latency is necessary but not sufficient. The large majority of the virus reservoir, CD4(+) T lymphocytes, is readily accessible but other minor reservoirs, where ART does not diffuse, require innovative strategies. The situation closely resembles that currently faced in the treatment of cancer. Exploiting the fact that histone deacetylase inhibitors, mainly vorinostat, may disrupt the latency of HIV-1, we propose to supplement this effect with a programmed interference in the metabolic stress of infected cells. Metformin and chloroquine are cheap and accessible modulators of pro-survival mechanisms to which viruses are constantly confronted to generate alternative energy sources and maximize virus production. Metformin restrains the use of the usurped cellular biosynthetic machinery by viral genes and chloroquine contributes to death of infected cells. We suggest that the combination of vorinostat, chloroquine and metformin should be combined with ART to pursue viral eradication in infected cells. PMID:23639282

  18. Giant viruses at the core of microscopic wars with global impacts.

    PubMed

    Villain, Adrien; Gallot-Lavallée, Lucie; Blanc, Guillaume; Maumus, Florian

    2016-04-01

    The unicellular eukaryotes (also called protists) that inhabit the contemporary oceans have large impacts on major biogeochemical cycles. Populations of oceanic protists are to a large extent regulated by their viral parasites, especially nucleocytoplasmic large DNA viruses (NCLDVs). NCLDVs can themselves be the prey of smaller viruses called virophages and can also be infected by transposable elements termed transpovirons. These entangled parasitisms have fostered the emergence of sophisticated infection and defence strategies. In addition persistent contact has facilitated the exchange of genes between different parties. Recent advances shed light on the strategies that govern such microbial wars. Endogenous virophage-like elements found in the genome of a marine alga could for instance provide the host acquired immunity against NCLDVs. In return, it was recently speculated that virophage sequences can be hijacked by NCLDVs and used as genetic weapons against virophages. PMID:27088734

  19. Diversity of Viruses Infecting the Green Microalga Ostreococcus lucimarinus

    PubMed Central

    Derelle, Evelyne; Monier, Adam; Cooke, Richard; Worden, Alexandra Z.

    2015-01-01

    ABSTRACT The functional diversity of eukaryotic viruses infecting a single host strain from seawater samples originating from distant marine locations is unknown. To estimate this diversity, we used lysis plaque assays to detect viruses that infect the widespread species Ostreococcus lucimarinus, which is found in coastal and mesotrophic systems, and O. tauri, which was isolated from coastal and lagoon sites from the northwest Mediterranean Sea. Detection of viral lytic activities against O. tauri was not observed using seawater from most sites, except those close to the area where the host strain was isolated. In contrast, the more cosmopolitan O. lucimarinus species recovered viruses from locations in the Atlantic and Pacific Oceans and the Mediterranean Sea. Six new O. lucimarinus viruses (OlVs) then were characterized and their genomes sequenced. Two subgroups of OlVs were distinguished based on their genetic distances and on the inversion of a central 32-kb-long DNA fragment, but overall their genomes displayed a high level of synteny. The two groups did not correspond to proximity of isolation sites, and the phylogenetic distance between these subgroups was higher than the distances observed among viruses infecting O. tauri. Our study demonstrates that viruses originating from very distant sites are able to infect the same algal host strain and can be more diverse than those infecting different species of the same genus. Finally, distinctive features and evolutionary distances between these different viral subgroups does not appear to be linked to biogeography of the viral isolates. IMPORTANCE Marine eukaryotic phytoplankton virus diversity has yet to be addressed, and more specifically, it is unclear whether diversity is connected to geographical distance and whether differential infection and lysis patterns exist among such viruses that infect the same host strain. Here, we assessed the genetic distance of geographically segregated viruses that infect the

  20. Viruses infecting Passiflora species in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report documents multiple viruses in Passiflora spp. in Florida. It also reiterates the risk of movement of vegetatively-propagated plant material. This report provides an overview of this virus for growers, extension workers, crop consultants and research and regulatory scientists....

  1. Neuraminidase inhibitors for influenza B virus infection: efficacy and resistance

    PubMed Central

    Burnham, Andrew J.; Baranovich, Tatiana; Govorkova, Elena A.

    2013-01-01

    Many aspects of the biology and epidemiology of influenza B viruses are far less studied than for influenza A viruses, and one of these aspects is effectiveness and resistance to the clinically available antiviral drugs, the neuraminidase (NA) inhibitors (NAIs). Acute respiratory infections are one of the leading causes of death in children and adults, and influenza is among the few respiratory infections that can be prevented and treated by vaccination and antiviral treatment. Recent data has suggested that influenza B virus infections are of specific concern to pediatric patients because of the increased risk of severe disease. Treatment of influenza B is a challenging task for the following reasons: NAIs (e.g., oseltamivir and zanamivir) are the only FDA-approved class of antivirals available for treatment;the data suggest that oseltamivir is less effective than zanamivir in pediatric patients;zanamivir is not prescribed to patients younger than 7;influenza B viruses are less susceptible than influenza A viruses to NAIs in vitro;although the level of resistance to NAIs is low, the number of different molecular markers of resistance is higher than for influenza A viruses, and they are not well defined;the relationship between levels of NAI phenotypic resistance and known molecular markers, frequency of emergence, transmissibility, and fitness of NAI-resistant variants are not well established. This review presents current knowledge of the effectiveness of NAIs for influenza B virus and antiviral resistance in clinical, surveillance, and experimental studies. PMID:24013000

  2. Infection of cells by Sindbis virus at low temperature

    SciTech Connect

    Wang Gongbo; Hernandez, Raquel; Weninger, Keith; Brown, Dennis T. . E-mail: dennis_brown@ncsu.edu

    2007-06-05

    Sindbis virus, which belongs to the family Togaviridae genus Alphavirus infects a variety of vertebrate and invertebrate cells. The initial steps of Sindbis virus infection involve attachment, penetration and uncoating. Two different pathways of infection have been proposed for Alphaviruses. One proposed mechanism involves receptor mediated virion endocytosis followed by membrane fusion triggered by endosome acidification. This virus-host membrane fusion model, well established by influenza virus, has been applied to other unrelated membrane-containing viruses including Alphaviruses. The other mechanism proposes direct penetration of the cell plasma membrane by the virus glycoproteins in the absence of membrane fusion. This alternate model is supported by both ultrastructural [Paredes, A.M., Ferreira, D., Horton, M., Saad, A., Tsuruta, H., Johnston, R., Klimstra, W., Ryman, K., Hernandez, R., Chiu, W., Brown, D.T., 2004. Conformational changes in Sindbis virions resulting from exposure to low pH and interactions with cells suggest that cell penetration may occur at the cell surface in the absence of membrane fusion. Virology 324(2), 373-386] and biochemical [Koschinski, A., Wengler, G., Wengler, G., and Repp, H., 2005. Rare earth ions block the ion pores generated by the class II fusion proteins of alphaviruses and allow analysis of the biological functions of these pores. J. Gen. Virol. 86(Pt. 12), 3311-3320] studies. We have examined the ability of Sindbis virus to infect Baby Hamster Kidney (BHK) cells at temperatures which block endocytosis. We have found that under these conditions Sindbis virus infects cells in a temperature- and time-dependent fashion.

  3. Infection of cells by Sindbis virus at low temperature.

    PubMed

    Wang, Gongbo; Hernandez, Raquel; Weninger, Keith; Brown, Dennis T

    2007-06-01

    Sindbis virus, which belongs to the family Togaviridae genus Alphavirus infects a variety of vertebrate and invertebrate cells. The initial steps of Sindbis virus infection involve attachment, penetration and uncoating. Two different pathways of infection have been proposed for Alphaviruses. One proposed mechanism involves receptor mediated virion endocytosis followed by membrane fusion triggered by endosome acidification. This virus-host membrane fusion model, well established by influenza virus, has been applied to other unrelated membrane-containing viruses including Alphaviruses. The other mechanism proposes direct penetration of the cell plasma membrane by the virus glycoproteins in the absence of membrane fusion. This alternate model is supported by both ultrastructural [Paredes, A.M., Ferreira, D., Horton, M., Saad, A., Tsuruta, H., Johnston, R., Klimstra, W., Ryman, K., Hernandez, R., Chiu, W., Brown, D.T., 2004. Conformational changes in Sindbis virions resulting from exposure to low pH and interactions with cells suggest that cell penetration may occur at the cell surface in the absence of membrane fusion. Virology 324(2), 373-386] and biochemical [Koschinski, A., Wengler, G., Wengler, G., and Repp, H., 2005. Rare earth ions block the ion pores generated by the class II fusion proteins of alphaviruses and allow analysis of the biological functions of these pores. J. Gen. Virol. 86(Pt. 12), 3311-3320] studies. We have examined the ability of Sindbis virus to infect Baby Hamster Kidney (BHK) cells at temperatures which block endocytosis. We have found that under these conditions Sindbis virus infects cells in a temperature- and time-dependent fashion. PMID:17289103

  4. Avian Influenza A Viruses: Evolution and Zoonotic Infection.

    PubMed

    Kim, Se Mi; Kim, Young-Il; Pascua, Philippe Noriel Q; Choi, Young Ki

    2016-08-01

    Although efficient human-to-human transmission of avian influenza virus has yet to be seen, in the past two decades avian-to-human transmission of influenza A viruses has been reported. Influenza A/H5N1, in particular, has repeatedly caused human infections associated with high mortality, and since 1998 the virus has evolved into many clades of variants with significant antigenic diversity. In 2013, three (A/H7N9, A/H6N1, and A/H10N8) novel avian influenza viruses (AIVs) breached the animal-human host species barrier in Asia. In humans, roughly 35% of A/H7N9-infected patients succumbed to the zoonotic infection, and two of three A/H10N8 human infections were also lethal; however, neither of these viruses cause influenza-like symptoms in poultry. While most of these cases were associated with direct contact with infected poultry, some involved sustained human-to-human transmission. Thus, these events elicited concern regarding potential AIV pandemics. This article reviews the human incursions associated with AIV variants and the potential role of pigs as an intermediate host that may hasten AIV evolution. In addition, we discuss the known influenza A virus virulence and transmission factors and their evaluation in animal models. With the growing number of human AIV infections, constant vigilance for the emergence of novel viruses is of utmost importance. In addition, careful characterization and pathobiological assessment of these novel variants will help to identify strains of particular concern for future pandemics. PMID:27486732

  5. Hepatitis E Virus Infection among Solid Organ Transplant Recipients, the Netherlands

    PubMed Central

    Pas, Suzan D.; de Man, Rob A.; Mulders, Claudia; Balk, Aggie H.M.M.; van Hal, Peter T.W.; Weimar, Willem; Koopmans, Marion P.G.; Osterhaus, Albert D.M.E.

    2012-01-01

    We screened 1,200 living heart, lung, liver, and kidney transplant recipients for hepatitis E virus infection by reverse transcription PCR. In 12 (1%) patients, hepatitis E virus infection was identified; in 11 patients, chronic infection developed. This immunocompromised population is at risk for hepatitis E virus infection. PMID:22516170

  6. Pathogenesis of Lassa Fever Virus Infection: I. Susceptibility of Mice to Recombinant Lassa Gp/LCMV Chimeric Virus

    PubMed Central

    Lee, Andrew M.; Cruite, Justin; Welch, Megan J.; Sullivan, Brian; Oldstone, Michael B.A.

    2013-01-01

    Lassa virus (LASV) is a BSL-4 restricted agent. To allow study of infection by LASV under BSL-2 conditions, we generated a recombinant virus in which the LASV glycoprotein (Gp) was placed on the backbone of lymphocytic choriomeningitis virus (LCMV) Cl13 nucleoprotein, Z and polymerase genes (rLCMV Cl13/LASV Gp). The recombinant virus displayed high tropism for dendritic cells following in vitro or in vivo infection. Inoculation of immunocompetent adults resulted in an acute infection, generation of virus-specific CD8+ T cells and clearance of the infection. Inoculation of newborn mice with rLCMV Cl13/LASV Gp resulted in a life-long persistent infection. Interestingly, adoptive transfer of rLCMV Cl13/LASV Gp immune memory cells into such persistently infected mice failed to purge virus but, in contrast, cleared virus from mice persistently infected with wt LCMV Cl13. PMID:23684417

  7. Pathogenesis of Lassa fever virus infection: I. Susceptibility of mice to recombinant Lassa Gp/LCMV chimeric virus.

    PubMed

    Lee, Andrew M; Cruite, Justin; Welch, Megan J; Sullivan, Brian; Oldstone, Michael B A

    2013-08-01

    Lassa virus (LASV) is a BSL-4 restricted agent. To allow study of infection by LASV under BSL-2 conditions, we generated a recombinant virus in which the LASV glycoprotein (Gp) was placed on the backbone of lymphocytic choriomeningitis virus (LCMV) Cl13 nucleoprotein, Z and polymerase genes (rLCMV Cl13/LASV Gp). The recombinant virus displayed high tropism for dendritic cells following in vitro or in vivo infection. Inoculation of immunocompetent adults resulted in an acute infection, generation of virus-specific CD8(+) T cells and clearance of the infection. Inoculation of newborn mice with rLCMV Cl13/LASV Gp resulted in a life-long persistent infection. Interestingly, adoptive transfer of rLCMV Cl13/LASV Gp immune memory cells into such persistently infected mice failed to purge virus but, in contrast, cleared virus from mice persistently infected with wt LCMV Cl13. PMID:23684417

  8. Pseudorabies Virus Infection Alters Neuronal Activity and Connectivity In Vitro

    PubMed Central

    McCarthy, Kelly M.; Tank, David W.; Enquist, Lynn W.

    2009-01-01

    Alpha-herpesviruses, including human herpes simplex virus 1 & 2, varicella zoster virus and the swine pseudorabies virus (PRV), infect the peripheral nervous system of their hosts. Symptoms of infection often include itching, numbness, or pain indicative of altered neurological function. To determine if there is an in vitro electrophysiological correlate to these characteristic in vivo symptoms, we infected cultured rat sympathetic neurons with well-characterized strains of PRV known to produce virulent or attenuated symptoms in animals. Whole-cell patch clamp recordings were made at various times after infection. By 8 hours of infection with virulent PRV, action potential (AP) firing rates increased substantially and were accompanied by hyperpolarized resting membrane potentials and spikelet-like events. Coincident with the increase in AP firing rate, adjacent neurons exhibited coupled firing events, first with AP-spikelets and later with near identical resting membrane potentials and AP firing. Small fusion pores between adjacent cell bodies formed early after infection as demonstrated by transfer of the low molecular weight dye, Lucifer Yellow. Later, larger pores formed as demonstrated by transfer of high molecular weight Texas red-dextran conjugates between infected cells. Further evidence for viral-induced fusion pores was obtained by infecting neurons with a viral mutant defective for glycoprotein B, a component of the viral membrane fusion complex. These infected neurons were essentially identical to mock infected neurons: no increased AP firing, no spikelet-like events, and no electrical or dye transfer. Infection with PRV Bartha, an attenuated circuit-tracing strain delayed, but did not eliminate the increased neuronal activity and coupling events. We suggest that formation of fusion pores between infected neurons results in electrical coupling and elevated firing rates, and that these processes may contribute to the altered neural function seen in PRV-infected

  9. Suppression of influenza virus infection by the orf virus isolated in Taiwan

    PubMed Central

    LIN, Fong-Yuan; TSENG, Yeu-Yang; CHAN, Kun-Wei; KUO, Shu-Ting; YANG, Cheng-Hsiung; WANG, Chi-Young; TAKASU, Masaki; HSU, Wei-Li; WONG, Min-Liang

    2015-01-01

    Orf virus (ORFV), a member of parapoxvirus, is an enveloped virus with genome of double-stranded DNA. ORFV causes contagious pustular dermatitis or contagious ecthyma in sheep and goats worldwide. In general, detection of viral DNA and observing ORFV virion in tissues of afflicted animals are two methods commonly used for diagnosis of orf infection; however, isolation of the ORFV in cell culture using virus-containing tissue as inoculum is known to be difficult. In this work, the ORFV (Hoping strain) isolated in central Taiwan was successfully grown in cell culture. We further examined the biochemical characteristic of our isolate, including viral genotyping, viral mRNA and protein expression. By electron microscopy, one unique form of viral particle from ORFV infected cellular lysate was demonstrated in the negative-stained field. Moreover, immunomodulating and anti-influenza virus properties of this ORFV were investigated. ORFV stimulated human monocytes (THP-1) secreting proinflammatory cytokines IL-8 and TNF-α. And, pre-treatment of ORFV-infected cell medium prevents A549 cells from subsequent type A influenza virus (IAV) infection. Similarly, mice infected with ORFV via both intramuscular and subcutaneous routes at two days prior to IAV infection significantly decreased the replication of IAV. In summary, the results of a current study indicated our Hoping strain harbors the immune modulator property; with such a bio-adjuvanticity, we further proved that pre-exposure of ORFV protects animals from subsequent IAV infection. PMID:25855509

  10. Eastern Equine Encephalomyelitis Virus Infection in a Horse from California

    PubMed Central

    Kinde, Hailu; Jay, Michele T.; Kramer, Laura D.; Green, Emily-Gene N.; Chiles, Robert E.; Ostlund, Eileen; Husted, Stan; Smith, Jonathan; Parker, Michael D.

    2002-01-01

    A yearling quarter horse, which was raised in southern California, received routine vaccinations for prevention of infection by Eastern equine encephalomyelitis virus (EEEV). One week later, severe neurologic signs developed, and the horse was humanely destroyed because vaccine-related encephalomyelitis was suspected. A final diagnosis of EEEV infection was established on the basis of acute onset of the neurologic signs, histopathologic and serologic testing, and isolation and molecular characterization of EEEV from brain tissue. The vaccine was extensively tested for viral inactivation. Nucleotide sequences from the vaccine and the virus isolated in the affected horse were also compared. In California, arboviral encephalomyelitides are rarely reported, and EEEV infection has not previously been documented. This report describes the occurrence of EEEV infection in the horse and the investigation to determine the source of infection, which was not definitively identified. PMID:11927026

  11. Quantitation of Productively Infected Monocytes and Macrophages of Simian Immunodeficiency Virus-Infected Macaques

    PubMed Central

    Avalos, Claudia R.; Price, Sarah L.; Forsyth, Ellen R.; Pin, Julia N.; Shirk, Erin N.; Bullock, Brandon T.; Queen, Suzanne E.; Li, Ming; Gellerup, Dane; O'Connor, Shelby L.; Zink, M. Christine; Mankowski, Joseph L.; Gama, Lucio

    2016-01-01

    ABSTRACT Despite the success of combined antiretroviral therapy (ART), human immunodeficiency virus (HIV) infection remains a lifelong infection because of latent viral reservoirs in infected patients. The contribution of CD4+ T cells to infection and disease progression has been extensively studied. However, during early HIV infection, macrophages in brain and other tissues are infected and contribute to tissue-specific diseases, such as encephalitis and dementia in brain and pneumonia in lung. The extent of infection of monocytes and macrophages has not been rigorously assessed with assays comparable to those used to study infection of CD4+ T cells and to evaluate the number of CD4+ T cells that harbor infectious viral genomes. To assess the contribution of productively infected monocytes and macrophages to HIV- and simian immunodeficiency virus (SIV)-infected cells in vivo, we developed a quantitative virus outgrowth assay (QVOA) based on similar assays used to quantitate CD4+ T cell latent reservoirs in HIV- and SIV-infected individuals in whom the infection is suppressed by ART. Myeloid cells expressing CD11b were serially diluted and cocultured with susceptible cells to amplify virus. T cell receptor β RNA was measured as a control to assess the potential contribution of CD4+ T cells in the assay. Virus production in the supernatant was quantitated by quantitative reverse transcription-PCR. Productively infected myeloid cells were detected in blood, bronchoalveolar lavage fluid, lungs, spleen, and brain, demonstrating that these cells persist throughout SIV infection and have the potential to contribute to the viral reservoir during ART. IMPORTANCE Infection of CD4+ T cells and their role as latent reservoirs have been rigorously assessed; however, the frequency of productively infected monocytes and macrophages in vivo has not been similarly studied. Myeloid cells, unlike lymphocytes, are resistant to the cytopathic effects of HIV. Moreover, tissue

  12. Occult hepatitis B virus infection among Mexican human immunodeficiency virus-1-infected patients

    PubMed Central

    Alvarez-Muñoz, Ma Teresa; Maldonado-Rodriguez, Angelica; Rojas-Montes, Othon; Torres-Ibarra, Rocio; Gutierrez-Escolano, Fernanda; Vazquez-Rosales, Guillermo; Gomez, Alejandro; Muñoz, Onofre; Torres, Javier; Lira, Rosalia

    2014-01-01

    AIM: To determine the frequency of occult hepatitis B infection (OHBI) in a group of human immunodeficiency virus (HIV)-1+/ hepatitis B surface antigen negative (HBsAg)- patients from Mexico. METHODS: We investigated the presence of OHBI in 49 HIV-1+/HBsAg- patients. Hepatitis B virus (HBV) DNA was analyzed using nested PCR to amplify the Core (C) region and by real-time PCR to amplify a region of the S and X genes. The possible associations between the variables and OHBI were investigated using Pearson’s χ2 and/or Fisher’s exact test. RESULTS: We found that the frequency of OHBI was 49% among the group of 49 HIV-1+/HBsAg- patients studied. The presence of OHBI was significantly associated with the HIV-1 RNA viral load [odds ratio (OR) = 8.75; P = 0.001; 95%CI: 2.26-33.79] and with HIV-antiretroviral treatment with drugs that interfere with HBV replication (lamivudine, tenofovir or emtricitabine) (OR = 0.25; P = 0.05; 95%CI: 0.08-1.05). CONCLUSION: The OHBI frequency is high among 49 Mexican HIV-1+/HBsAg- patients and it was more frequent in patients with detectable HIV RNA, and less frequent in patients who are undergoing HIV-ARV treatment with drugs active against HBV. PMID:25309083

  13. Zika virus infections: An overview of current scenario.

    PubMed

    Dasti, Javid Iqbal

    2016-07-01

    Zika virus (ZIKV) was discovered more than half a century ago, recently it has gained unprecedented attention by the global health community. Until 2007, only 14 cases of human ZIKV infections were reported around the globe, while during the current outbreak, estimated cases mounted to approximately 1.5 million in Brazil alone, the virus was disseminated to wider South-American territories and travel-associated ZIKV infections were reported in USA, Europe and recently in China. ZIKV infections remain asymptomatic in approximately 80% of the individuals, and no anti-viral treatments were recommended. Yet, neurological complications associated with the infections, such as infant microcephaly and Guillain-Barré syndrome are major cause of the concern. Although, based on small numbers of cases, existing evidence strongly supports an exclusive link of viral infection and observed neurological complications. However, much work remains to assign exact numbers of complications caused by ZIKV. Regarding its structural attributes ZIKV shows remarkable resemblance with dengue virus and West-Nile virus. Despite, genomes of different ZIKV strains have already been decoded; role of the viral components in infection process and particularly pathogenesis of the disease remain widely unclear. In vulnerable areas, most viable strategy to ensure public health safety is vector control and enhanced public awareness about the transmission of the disease. PMID:27393087

  14. Innate immune targets of hepatitis B virus infection

    PubMed Central

    Zou, Zhi-Qiang; Wang, Li; Wang, Kai; Yu, Ji-Guang

    2016-01-01

    Approximately 400 million people are chronically infected with hepatitis B virus (HBV) globally despite the widespread immunization of HBV vaccine and the development of antiviral therapies. The immunopathogenesis of HBV infection is initiated and driven by complexed interactions between the host immune system and the virus. Host immune responses to viral particles and proteins are regarded as the main determinants of viral clearance or persistent infection and hepatocyte injury. Innate immune system is the first defending line of host preventing from virus invasion. It is acknowledged that HBV has developed active tactics to escape innate immune recognition or actively interfere with innate immune signaling pathways and induce immunosuppression, which favor their replication. HBV reduces the expression of pattern-recognition receptors in the innate immune cells in humans. Also, HBV may interrupt different parts of antiviral signaling pathways, leading to the reduced production of antiviral cytokines such as interferons that contribute to HBV immunopathogenesis. A full comprehension of the mechanisms as to how HBV inactivates various elements of the innate immune response to initiate and maintain a persistent infection can be helpful in designing new immunotherapeutic methods for preventing and eradicating the virus. In this review, we aimed to summarize different branches the innate immune targeted by HBV infection. The review paper provides evidence that multiple components of immune responses should be activated in combination with antiviral therapy to disrupt the tolerance to HBV for eliminating HBV infection. PMID:27330680

  15. Innate immune targets of hepatitis B virus infection.

    PubMed

    Zou, Zhi-Qiang; Wang, Li; Wang, Kai; Yu, Ji-Guang

    2016-06-18

    Approximately 400 million people are chronically infected with hepatitis B virus (HBV) globally despite the widespread immunization of HBV vaccine and the development of antiviral therapies. The immunopathogenesis of HBV infection is initiated and driven by complexed interactions between the host immune system and the virus. Host immune responses to viral particles and proteins are regarded as the main determinants of viral clearance or persistent infection and hepatocyte injury. Innate immune system is the first defending line of host preventing from virus invasion. It is acknowledged that HBV has developed active tactics to escape innate immune recognition or actively interfere with innate immune signaling pathways and induce immunosuppression, which favor their replication. HBV reduces the expression of pattern-recognition receptors in the innate immune cells in humans. Also, HBV may interrupt different parts of antiviral signaling pathways, leading to the reduced production of antiviral cytokines such as interferons that contribute to HBV immunopathogenesis. A full comprehension of the mechanisms as to how HBV inactivates various elements of the innate immune response to initiate and maintain a persistent infection can be helpful in designing new immunotherapeutic methods for preventing and eradicating the virus. In this review, we aimed to summarize different branches the innate immune targeted by HBV infection. The review paper provides evidence that multiple components of immune responses should be activated in combination with antiviral therapy to disrupt the tolerance to HBV for eliminating HBV infection. PMID:27330680

  16. Finding balance: Virus populations reach equilibrium during the infection process.

    PubMed

    Harper, S J; Cowell, S J; Dawson, W O

    2015-11-01

    Virus populations, mixtures of viral strains or species, are a common feature of viral infection, and influence many viral processes including infection, transmission, and the induction of disease. Yet, little is known of the rules that define the composition and structure of these populations. In this study, we used three distinct strains of Citrus tristeza virus (CTV) to examine the effect of inoculum composition, titer, and order, on the virus population. We found that CTV populations stabilized at the same equilibrium irrespective of how that population was introduced into a host. In addition, both field and experimental observations showed that these equilibria were relatively uniform between individual hosts of the same species and under the same conditions. We observed that the structure of the equilibria reached is determined primarily by the host, with the same inoculum reaching different equilibria in different species, and by the fitness of individual virus variants. PMID:26291064

  17. Genomic comparison of closely related Giant Viruses supports an accordion-like model of evolution.

    PubMed

    Filée, Jonathan

    2015-01-01

    Genome gigantism occurs so far in Phycodnaviridae and Mimiviridae (order Megavirales). Origin and evolution of these Giant Viruses (GVs) remain open questions. Interestingly, availability of a collection of closely related GV genomes enabling genomic comparisons offer the opportunity to better understand the different evolutionary forces acting on these genomes. Whole genome alignment for five groups of viruses belonging to the Mimiviridae and Phycodnaviridae families show that there is no trend of genome expansion or general tendency of genome contraction. Instead, GV genomes accumulated genomic mutations over the time with gene gains compensating the different losses. In addition, each lineage displays specific patterns of genome evolution. Mimiviridae (megaviruses and mimiviruses) and Chlorella Phycodnaviruses evolved mainly by duplications and losses of genes belonging to large paralogous families (including movements of diverse mobiles genetic elements), whereas Micromonas and Ostreococcus Phycodnaviruses derive most of their genetic novelties thought lateral gene transfers. Taken together, these data support an accordion-like model of evolution in which GV genomes have undergone successive steps of gene gain and gene loss, accrediting the hypothesis that genome gigantism appears early, before the diversification of the different GV lineages. PMID:26136734

  18. Genomic comparison of closely related Giant Viruses supports an accordion-like model of evolution

    PubMed Central

    Filée, Jonathan

    2015-01-01

    Genome gigantism occurs so far in Phycodnaviridae and Mimiviridae (order Megavirales). Origin and evolution of these Giant Viruses (GVs) remain open questions. Interestingly, availability of a collection of closely related GV genomes enabling genomic comparisons offer the opportunity to better understand the different evolutionary forces acting on these genomes. Whole genome alignment for five groups of viruses belonging to the Mimiviridae and Phycodnaviridae families show that there is no trend of genome expansion or general tendency of genome contraction. Instead, GV genomes accumulated genomic mutations over the time with gene gains compensating the different losses. In addition, each lineage displays specific patterns of genome evolution. Mimiviridae (megaviruses and mimiviruses) and Chlorella Phycodnaviruses evolved mainly by duplications and losses of genes belonging to large paralogous families (including movements of diverse mobiles genetic elements), whereas Micromonas and Ostreococcus Phycodnaviruses derive most of their genetic novelties thought lateral gene transfers. Taken together, these data support an accordion-like model of evolution in which GV genomes have undergone successive steps of gene gain and gene loss, accrediting the hypothesis that genome gigantism appears early, before the diversification of the different GV lineages. PMID:26136734

  19. mRNA maturation in giant viruses: variation on a theme

    PubMed Central

    Priet, Stéphane; Lartigue, Audrey; Debart, Françoise; Claverie, Jean-Michel; Abergel, Chantal

    2015-01-01

    Giant viruses from the Mimiviridae family replicate entirely in their host cytoplasm where their genes are transcribed by a viral transcription apparatus. mRNA polyadenylation uniquely occurs at hairpin-forming palindromic sequences terminating viral transcripts. Here we show that a conserved gene cluster both encode the enzyme responsible for the hairpin cleavage and the viral polyA polymerases (vPAP). Unexpectedly, the vPAPs are homodimeric and uniquely self-processive. The vPAP backbone structures exhibit a symmetrical architecture with two subdomains sharing a nucleotidyltransferase topology, suggesting that vPAPs originate from an ancestral duplication. A Poxvirus processivity factor homologue encoded by Megavirus chilensis displays a conserved 5′-GpppA 2′O methyltransferase activity but is also able to internally methylate the mRNAs’ polyA tails. These findings elucidate how the arm wrestling between hosts and their viruses to access the translation machinery is taking place in Mimiviridae. PMID:25779049

  20. Persistent virus and addiction modules: an engine of symbiosis.

    PubMed

    Villarreal, Luis P

    2016-06-01

    The giant DNA viruses are highly prevalent and have a particular affinity for the lytic infection of unicellular eukaryotic host. The giant viruses can also be infected by inhibitory virophage which can provide lysis protection to their host. The combined protective and destructive action of such viruses can define a general model (PD) of virus-mediated host survival. Here, I present a general model for role such viruses play in the evolution of host symbiosis. By considering how virus mixtures can participate in addiction modules, I provide a functional explanation for persistence of virus derived genetic 'junk' in their host genomic habitats. PMID:27039268

  1. Neutralizing antibodies in Borna disease virus-infected rats.

    PubMed Central

    Hatalski, C G; Kliche, S; Stitz, L; Lipkin, W I

    1995-01-01

    Borna disease is a neurologic syndrome caused by infection with a nonsegmented, negative-strand RNA virus, Borna disease virus. Infected animals have antibodies to two soluble viral proteins, p40 and p23, and a membrane-associated viral glycoprotein, gp18. We examined the time course for the development of neutralization activity and the expression of antibodies to individual viral proteins in sera of infected rats. The appearance of neutralizing activity correlated with the development of immunoreactivity to gp18, but not p40 or p23. Monospecific and monoclonal antibodies to native gp18 and recombinant nonglycosylated gp18 were also found to have neutralizing activity and to immunoprecipitate viral particles or subparticles. These findings suggest that gp18 is likely to be present on the surface of the viral particles and is likely to contain epitopes important for virus neutralization. PMID:7815538

  2. Cohabitation reaction-diffusion model for virus focal infections

    NASA Astrophysics Data System (ADS)

    Amor, Daniel R.; Fort, Joaquim

    2014-12-01

    The propagation of virus infection fronts has been typically modeled using a set of classical (noncohabitation) reaction-diffusion equations for interacting species. However, for some single-species systems it has been recently shown that noncohabitation reaction-diffusion equations may lead to unrealistic descriptions. We argue that previous virus infection models also have this limitation, because they assume that a virion can simultaneously reproduce inside a cell and diffuse away from it. For this reason, we build a several-species cohabitation model that does not have this limitation. Furthermore, we perform a sensitivity analysis for the most relevant parameters of the model, and we compare the predicted infection speed with observed data for two different strains of the T7 virus.

  3. The First Imported Case Infected with Chikungunya Virus in Korea

    PubMed Central

    2015-01-01

    Chikungunya is caused by an arbovirus transmitted by Aedes mosquito vector. With the increase of habitat of mosquito by global warming and frequent international travel and interchange, chikungunya reemerged and showed global distribution recently. Until now there has not been reported any case infected with chikungunya virus in Korea. A 23-year-old man has been the Republic of the Philippines for 1 week, and visited our emergency center due to fever and back pain. Chikungunya viral infection was diagnosed by specific IgM for chickungunya virus by enzyme-linked immunosorbent assayin Korea Centers for Disease Control and Prevention. His clinical course was self limited. We introduce the first imported case infected with chikungunya virus in Korea. PMID:25844264

  4. Targeting Viral Proteostasis Limits Influenza Virus, HIV, and Dengue Virus Infection.

    PubMed

    Heaton, Nicholas S; Moshkina, Natasha; Fenouil, Romain; Gardner, Thomas J; Aguirre, Sebastian; Shah, Priya S; Zhao, Nan; Manganaro, Lara; Hultquist, Judd F; Noel, Justine; Sachs, David; Sachs, David H; Hamilton, Jennifer; Leon, Paul E; Chawdury, Amit; Tripathi, Shashank; Melegari, Camilla; Campisi, Laura; Hai, Rong; Metreveli, Giorgi; Gamarnik, Andrea V; García-Sastre, Adolfo; Greenbaum, Benjamin; Simon, Viviana; Fernandez-Sesma, Ana; Krogan, Nevan J; Mulder, Lubbertus C F; van Bakel, Harm; Tortorella, Domenico; Taunton, Jack; Palese, Peter; Marazzi, Ivan

    2016-01-19

    Viruses are obligate parasites and thus require the machinery of the host cell to replicate. Inhibition of host factors co-opted during active infection is a strategy hosts use to suppress viral replication and a potential pan-antiviral therapy. To define the cellular proteins and processes required for a virus during infection is thus crucial to understanding the mechanisms of virally induced disease. In this report, we generated fully infectious tagged influenza viruses and used infection-based proteomics to identify pivotal arms of cellular signaling required for influenza virus growth and infectivity. Using mathematical modeling and genetic and pharmacologic approaches, we revealed that modulation of Sec61-mediated cotranslational translocation selectively impaired glycoprotein proteostasis of influenza as well as HIV and dengue viruses and led to inhibition of viral growth and infectivity. Thus, by studying virus-human protein-protein interactions in the context of active replication, we have identified targetable host factors for broad-spectrum antiviral therapies. PMID:26789921

  5. Mitochondrial dysfunction in rabies virus infection of neurons.

    PubMed

    Alandijany, Thamir; Kammouni, Wafa; Roy Chowdhury, Subir K; Fernyhough, Paul; Jackson, Alan C

    2013-12-01

    Infection with the challenge virus standard-11 (CVS) strain of fixed rabies virus induces neuronal process degeneration in adult mice after hindlimb footpad inoculation. CVS-induced axonal swellings of primary rodent dorsal root ganglion neurons are associated with 4-hydroxy-2-nonenal protein adduct staining, indicating a critical role of oxidative stress. Mitochondrial dysfunction is the major cause of oxidative stress. We hypothesized that CVS infection induces mitochondrial dysfunction leading to oxidative stress. We investigated the effects of CVS infection on several mitochondrial parameters in different cell types. CVS infection significantly increased maximal uncoupled respiration and complex IV respiration and complex I and complex IV activities, but did not affect complex II-III or citrate synthase activities. Increases in complex I activity, but not complex IV activity, correlated with susceptibility of the cells to CVS infection. CVS infection maintained coupled respiration and rate of proton leak, indicating a tight mitochondrial coupling. Possibly as a result of enhanced complex activity and efficient coupling, a high mitochondrial membrane potential was generated. CVS infection reduced the intracellular ATP level and altered the cellular redox state as indicated by a high NADH/NAD+ ratio. The basal production of reactive oxygen species (ROS) was not affected in CVS-infected neurons. However, a higher rate of ROS generation occurred in CVS-infected neurons in the presence of mitochondrial substrates and inhibitors. We conclude that CVS infection induces mitochondrial dysfunction leading to ROS overgeneration and oxidative stress. PMID:24277436

  6. Background review for diagnostic test development for Zika virus infection

    PubMed Central

    Charrel, Rémi N; Leparc-Goffart, Isabelle; Pas, Suzan; de Lamballerie, Xavier; Koopmans, Marion; Reusken, Chantal

    2016-01-01

    Abstract Objective To review the state of knowledge about diagnostic testing for Zika virus infection and identify areas of research needed to address the current gaps in knowledge. Methods We made a non-systematic review of the published literature about Zika virus and supplemented this with information from commercial diagnostic test kits and personal communications with researchers in European preparedness networks. The review covered current knowledge about the geographical spread, pathogen characteristics, life cycle and infection kinetics of the virus. The available molecular and serological tests and biosafety issues are described and discussed in the context of the current outbreak strain. Findings We identified the following areas of research to address current knowledge gaps: (i) an urgent assessment of the laboratory capacity and capability of countries to detect Zika virus; (ii) rapid and extensive field validation of the available molecular and serological tests in areas with and without Zika virus transmission, with a focus on pregnant women; (iii) monitoring the genomic diversity of circulating Zika virus strains; (iv) prospective studies into the virus infection kinetics, focusing on diagnostic sampling (specimen types, combinations and timings); and (v) developing external quality assessments for molecular and serological testing, including differential diagnosis for similar viruses and symptom clusters. The availability of reagents for diagnostic development (virus strains and antigens, quantified viral ribonucleic acid) needs to be facilitated. Conclusion An international laboratory response is needed, including preparation of protocols for prospective studies to address the most pressing information needs. PMID:27516635

  7. Permissive and restricted virus infection of murine embryonic stem cells.

    PubMed

    Wash, Rachael; Calabressi, Sabrina; Franz, Stephanie; Griffiths, Samantha J; Goulding, David; Tan, E-Pien; Wise, Helen; Digard, Paul; Haas, Jürgen; Efstathiou, Stacey; Kellam, Paul

    2012-10-01

    Recent RNA interference (RNAi) studies have identified many host proteins that modulate virus infection, but small interfering RNA 'off-target' effects and the use of transformed cell lines limit their conclusiveness. As murine embryonic stem (mES) cells can be genetically modified and resources exist where many and eventually all known mouse genes are insertionally inactivated, it was reasoned that mES cells would provide a useful alternative to RNAi screens. Beyond allowing investigation of host-pathogen interactions in vitro, mES cells have the potential to differentiate into other primary cell types, as well as being used to generate knockout mice for in vivo studies. However, mES cells are poorly characterized for virus infection. To investigate whether ES cells can be used to explore host-virus interactions, this study characterized the responses of mES cells following infection by herpes simplex virus type 1 (HSV-1) and influenza A virus. HSV-1 replicated lytically in mES cells, although mES cells were less permissive than most other cell types tested. Influenza virus was able to enter mES cells and express some viral proteins, but the replication cycle was incomplete and no infectious virus was produced. Knockdown of the host protein AHCYL1 in mES cells reduced HSV-1 replication, showing the potential for using mES cells to study host-virus interactions. Transcriptional profiling, however, indicated the lack of an efficient innate immune response in these cells. mES cells may thus be useful to identify host proteins that play a role in virus replication, but they are not suitable to determine factors that are involved in innate host defence. PMID:22815272

  8. Permissive and restricted virus infection of murine embryonic stem cells

    PubMed Central

    Wash, Rachael; Calabressi, Sabrina; Franz, Stephanie; Griffiths, Samantha J.; Goulding, David; Tan, E-Pien; Wise, Helen; Digard, Paul; Haas, Jürgen; Efstathiou, Stacey

    2012-01-01

    Recent RNA interference (RNAi) studies have identified many host proteins that modulate virus infection, but small interfering RNA ‘off-target’ effects and the use of transformed cell lines limit their conclusiveness. As murine embryonic stem (mES) cells can be genetically modified and resources exist where many and eventually all known mouse genes are insertionally inactivated, it was reasoned that mES cells would provide a useful alternative to RNAi screens. Beyond allowing investigation of host–pathogen interactions in vitro, mES cells have the potential to differentiate into other primary cell types, as well as being used to generate knockout mice for in vivo studies. However, mES cells are poorly characterized for virus infection. To investigate whether ES cells can be used to explore host–virus interactions, this study characterized the responses of mES cells following infection by herpes simplex virus type 1 (HSV-1) and influenza A virus. HSV-1 replicated lytically in mES cells, although mES cells were less permissive than most other cell types tested. Influenza virus was able to enter mES cells and express some viral proteins, but the replication cycle was incomplete and no infectious virus was produced. Knockdown of the host protein AHCYL1 in mES cells reduced HSV-1 replication, showing the potential for using mES cells to study host–virus interactions. Transcriptional profiling, however, indicated the lack of an efficient innate immune response in these cells. mES cells may thus be useful to identify host proteins that play a role in virus replication, but they are not suitable to determine factors that are involved in innate host defence. PMID:22815272

  9. Seroepidemiology of Asymptomatic Dengue Virus Infection in Jeddah, Saudi Arabia

    PubMed Central

    Jamjoom, Ghazi A.; Azhar, Esam I.; Kao, Moujahid A.; Radadi, Raja M.

    2016-01-01

    BACKGROUND Although virologically confirmed dengue fever has been recognized in Jeddah, Saudi Arabia, since 1994, causing yearly outbreaks, no proper seroepidemiologic studies on dengue virus have been conducted in this region. Such studies can define the extent of infection by this virus and estimate the proportion that may result in disease. The aim of this study was to measure the seroprevalence of past dengue virus infection in healthy Saudi nationals from different areas in the city of Jeddah and to investigate demographic and environmental factors that may increase exposure to infection. METHODS Sera were collected from 1984 Saudi subjects attending primary health care centers in six districts of Jeddah. These included general patients of various ages seeking routine vaccinations, antenatal care or treatment of different illnesses excluding fever or suspected dengue. A number of blood donors were also tested. Serum samples were tested by enzyme immunoassay (EIA) for IgG antibodies to dengue viruses 1, 2, 3, 4. A questionnaire was completed for each patient recording various anthropometric data and factors that may indicate possible risk of exposure to mosquito bites and dengue infection. Patients with missing data and those who reported a history of dengue fever were excluded from analysis, resulting in a sample of 1939 patients to be analyzed. RESULTS The overall prevalence of dengue virus infection as measured by anti-dengue IgG antibodies from asymptomatic residents in Jeddah was 47.8% (927/1939) and 37% (68/184) in blood donors. Infection mostly did not result in recognizable disease, as only 19 of 1956 subjects with complete information (0.1%) reported having dengue fever in the past. Anti dengue seropositivity increased with age and was higher in males than females and in residents of communal housing and multistory buildings than in villas. One of the six districts showed significant increase in exposure rate as compared to the others. Availability of

  10. Japanese encephalitis virus tropism in experimentally infected pigs.

    PubMed

    Ricklin, Meret E; Garcìa-Nicolàs, Obdulio; Brechbühl, Daniel; Python, Sylvie; Zumkehr, Beatrice; Posthaus, Horst; Oevermann, Anna; Summerfield, Artur

    2016-01-01

    Pigs are considered to be the main amplifying host for Japanese encephalitis virus (JEV), and their infection can correlate with human cases of disease. Despite their importance in the ecology of the virus as it relates to human cases of encephalitis, the pathogenesis of JEV in pigs remains obscure. In the present study, the localization and kinetics of virus replication were investigated in various tissues after experimental intravenous infection of pigs. The data demonstrate a rapid and broad spreading of the virus to the central nervous system (CNS) and various other organs. A particular tropism of JEV in pigs not only to the CNS but also for secondary lymphoid tissue, in particular the tonsils with the overall highest viral loads, was observed. In this organ, even 11 days post infection, the latest time point of the experiment, no apparent decrease in viral RNA loads and live virus was found despite the presence of a neutralizing antibody response. This was also well beyond the clinical and viremic phase. These results are of significance for the pathogenesis of JEV, and call for further experimental studies focusing on the cellular source and duration of virus replication in pigs. PMID:26911997

  11. Possible Association Between Zika Virus Infection and Microcephaly - Brazil, 2015.

    PubMed

    Schuler-Faccini, Lavinia; Ribeiro, Erlane M; Feitosa, Ian M L; Horovitz, Dafne D G; Cavalcanti, Denise P; Pessoa, André; Doriqui, Maria Juliana R; Neri, Joao Ivanildo; Neto, Joao Monteiro de Pina; Wanderley, Hector Y C; Cernach, Mirlene; El-Husny, Antonette S; Pone, Marcos V S; Serao, Cassio L C; Sanseverino, Maria Teresa V

    2016-01-01

    In early 2015, an outbreak of Zika virus, a flavivirus transmitted by Aedes mosquitoes, was identified in northeast Brazil, an area where dengue virus was also circulating. By September, reports of an increase in the number of infants born with microcephaly in Zika virus-affected areas began to emerge, and Zika virus RNA was identified in the amniotic fluid of two women whose fetuses had been found to have microcephaly by prenatal ultrasound. The Brazil Ministry of Health (MoH) established a task force to investigate the possible association of microcephaly with Zika virus infection during pregnancy and a registry for incident microcephaly cases (head circumference ≥2 standard deviations [SD] below the mean for sex and gestational age at birth) and pregnancy outcomes among women suspected to have had Zika virus infection during pregnancy. Among a cohort of 35 infants with microcephaly born during August-October 2015 in eight of Brazil's 26 states and reported to the registry, the mothers of all 35 had lived in or visited Zika virus-affected areas during pregnancy, 25 (71%) infants had severe microcephaly (head circumference >3 SD below the mean for sex and gestational age), 17 (49%) had at least one neurologic abnormality, and among 27 infants who had neuroimaging studies, all had abnormalities. Tests for other congenital infections were negative. All infants had a lumbar puncture as part of the evaluation and cerebrospinal fluid (CSF) samples were sent to a reference laboratory in Brazil for Zika virus testing; results are not yet available. Further studies are needed to confirm the association of microcephaly with Zika virus infection during pregnancy and to understand any other adverse pregnancy outcomes associated with Zika virus infection. Pregnant women in Zika virus-affected areas should protect themselves from mosquito bites by using air conditioning, screens, or nets when indoors, wearing long sleeves and pants, using permethrin-treated clothing and gear

  12. Insights into human immunodeficiency virus-hepatitis B virus co-infection in India

    PubMed Central

    Chakravarty, Runu; Pal, Ananya

    2015-01-01

    Shared routes of transmission lead to frequent human immunodeficiency virus (HIV)-hepatitis B virus (HBV) co-infection in a host which results in about 10% of HIV positive individuals to have chronic hepatitis B infection worldwide. In post-antiretroviral therapy era, liver diseases have emerged as the leading cause of morbidity and mortality in HIV-infected individuals and HBV co-infection have become the major health issue among this population particularly from the regions with endemic HBV infection. In setting of HIV-HBV co-infection, HIV significantly impacts the natural history of HBV infection, its disease profile and the treatment outcome in negative manner. Moreover, the epidemiological pattern of HBV infection and the diversity in HBV genome (genotypic and phenotypic) are also varied in HIV co-infected subjects as compared to HBV mono-infected individuals. Several reports on the abovementioned issues are available from developed parts of the world as well as from sub-Saharan African countries. In contrast, most of these research areas remained unexplored in India despite having considerable burden of HIV and HBV infections. This review discusses present knowledge from the studies on HIV-HBV co-infection in India and relevant reports from different parts of the world. Issues needed for the future research relevant to HIV-HBV co-infection in India are also highlighted here, including a call for further investigations on this field of study. PMID:26279986

  13. First study of different insect cells to triatoma virus infection.

    PubMed

    Susevich, María Laura; Marti, Gerardo Aníbal; Metz, Germán Ernesto; Echeverría, María Gabriela

    2015-04-01

    The use of viruses for biological control is a new option to be considered. The family Dicistroviridae, which affects only invertebrates, is one of the families that have been proposed for this purpose. The Triatoma virus (TrV), a member of this family, affects triatomine transmitters of Chagas disease, which is endemic in Latin America but also expanding its worldwide distribution. To this end, we attempted virus replication in Diptera, Aedes albopictus (clone C6/36) and Lepidoptera Spodoptera frugiperda (SF9, SF21) and High Five (H5) cell lines. The methodologies used were transfection process, direct inoculation (purified virus), and inoculation of purified virus with trypsin. Results were confirmed by SDS-PAGE, Western blotting, RT-PCR, electron microscopy, and immunofluorescence. According to the results obtained, further analysis of susceptibility/infection of H5 cells to TrV required to be studied. PMID:25481388

  14. Protective and Pathogenic Responses to Chikungunya Virus Infection

    PubMed Central

    Long, Kristin M.; Heise, Mark T.

    2015-01-01

    Chikungunya virus (CHIKV) is an arbovirus responsible for causing epidemic outbreaks of human disease characterized by painful and often debilitating arthralgia. Recently CHIKV has moved into the Caribbean and the Americas resulting in massive outbreaks in naïve human populations. Given the importance of CHIKV as an emerging disease, a significant amount of effort has gone into interpreting the virus-host interactions that contribute to protection or virus-induced pathology following CHIKV infection, with the long term goal of using this information to develop new therapies or safe and effective anti-CHIKV vaccines. This work has made it clear that numerous distinct host responses are involved in the response to CHIKV infection, where some aspects of the host innate and adaptive immune response protect from or limit virus-induced disease, while other pathways actually exacerbate the virus-induced disease process. This review will discuss mechanisms that have been identified as playing a role in the host response to CHIKV infection and illustrate the importance of carefully evaluating these responses to determine whether they play a protective or pathologic role during CHIKV infection. PMID:26366337

  15. Persistent infection of chimpanzees with human immunodeficiency virus: serological responses and properties of reisolated viruses.

    PubMed Central

    Nara, P L; Robey, W G; Arthur, L O; Asher, D M; Wolff, A V; Gibbs, C J; Gajdusek, D C; Fischinger, P J

    1987-01-01

    Persistent infection by human immunodeficiency virus (HIV-1) in the chimpanzee may be valuable for immunopathologic and potential vaccine evaluation. Two HIV strains, the tissue culture-derived human T-cell lymphotropic virus type IIIB (HTLV-IIIB) and in vivo serially passaged lymphadenopathy-associated virus type 1 (LAV-1), were injected intravenously into chimpanzees. Two animals received HTLV-IIIB as either virus-infected H9 cells or cell-free virus. A third animal received chimpanzee-passaged LAV-1. Evaluation of their sera for virus-specific serologic changes, including neutralizations, was done during a 2-year period. During this period all animals had persistently high titers of antibodies to viral core and envelope antigens. All three animals developed a progressively increasing type-specific neutralizing LAV-1 versus HTLV-IIIB antibody titer during the 2-year observation period which broadened in specificity to include HTLV-HIRF, HTLV-IIIMN, and HTLV-IIICC after 6 to 12 months. The antibody titers against both viruses were still increasing by 2 years after experimental virus inoculation. Sera from all animals were capable of neutralizing both homologously and heterologously reisolated virus from chimpanzees. A slightly more rapid type-specific neutralizing response was noted for the animal receiving HTLV-IIIB-infected cells compared with that for cell-free HTLV-IIIB. Sera from all persistently infected chimpanzees were capable of mediating group-specific antibody-mediated complement-dependent cytolysis of HIV-infected cells derived from all isolates tested. Viruses reisolated from all three animals at 20 months after inoculation revealed very similar peptide maps of their respective envelope gp120s, as determined by two-dimensional chymotrypsin oligopeptide analysis. One peptide, however, from the original HTLV-IIIB-inoculated virus was deleted in viruses from all three animals, and in addition, we noted the appearance of a new or modified peptide which

  16. Persistent infection of chimpanzees with human immunodeficiency virus: serological responses and properties of reisolated viruses.

    PubMed

    Nara, P L; Robey, W G; Arthur, L O; Asher, D M; Wolff, A V; Gibbs, C J; Gajdusek, D C; Fischinger, P J

    1987-10-01

    Persistent infection by human immunodeficiency virus (HIV-1) in the chimpanzee may be valuable for immunopathologic and potential vaccine evaluation. Two HIV strains, the tissue culture-derived human T-cell lymphotropic virus type IIIB (HTLV-IIIB) and in vivo serially passaged lymphadenopathy-associated virus type 1 (LAV-1), were injected intravenously into chimpanzees. Two animals received HTLV-IIIB as either virus-infected H9 cells or cell-free virus. A third animal received chimpanzee-passaged LAV-1. Evaluation of their sera for virus-specific serologic changes, including neutralizations, was done during a 2-year period. During this period all animals had persistently high titers of antibodies to viral core and envelope antigens. All three animals developed a progressively increasing type-specific neutralizing LAV-1 versus HTLV-IIIB antibody titer during the 2-year observation period which broadened in specificity to include HTLV-HIRF, HTLV-IIIMN, and HTLV-IIICC after 6 to 12 months. The antibody titers against both viruses were still increasing by 2 years after experimental virus inoculation. Sera from all animals were capable of neutralizing both homologously and heterologously reisolated virus from chimpanzees. A slightly more rapid type-specific neutralizing response was noted for the animal receiving HTLV-IIIB-infected cells compared with that for cell-free HTLV-IIIB. Sera from all persistently infected chimpanzees were capable of mediating group-specific antibody-mediated complement-dependent cytolysis of HIV-infected cells derived from all isolates tested. Viruses reisolated from all three animals at 20 months after inoculation revealed very similar peptide maps of their respective envelope gp120s, as determined by two-dimensional chymotrypsin oligopeptide analysis. One peptide, however, from the original HTLV-IIIB-inoculated virus was deleted in viruses from all three animals, and in addition, we noted the appearance of a new or modified peptide which

  17. The Human Immunodeficiency Virus: Infectivity and Mechanisms of Pathogenesis

    NASA Astrophysics Data System (ADS)

    Fauci, Anthony S.

    1988-02-01

    Infection with the human immunodeficiency virus (HIV) results in a profound immunosuppression due predominantly to a selective depletion of helper/inducer T lymphocytes that express the receptor for the virus (the CD4 molecule). HIV also has tropism for the brain leading to neuropsychiatric abnormalities. Besides inducing cell death, HIV can interfere with T4 cell function by various mechanisms. The monocyte serves as a reservoir for HIV and is relatively refractory to its cytopathic effects. HIV can exist in a latent or chronic form which can be converted to a productive infection by a variety of inductive signals.

  18. Beet western yellows virus infects the carnivorous plant Nepenthes mirabilis.

    PubMed

    Miguel, Sissi; Biteau, Flore; Mignard, Benoit; Marais, Armelle; Candresse, Thierry; Theil, Sébastien; Bourgaud, Frédéric; Hehn, Alain

    2016-08-01

    Although poleroviruses are known to infect a broad range of higher plants, carnivorous plants have not yet been reported as hosts. Here, we describe the first polerovirus naturally infecting the pitcher plant Nepenthes mirabilis. The virus was identified through bioinformatic analysis of NGS transcriptome data. The complete viral genome sequence was assembled from overlapping PCR fragments and shown to share 91.1 % nucleotide sequence identity with the US isolate of beet western yellows virus (BWYV). Further analysis of other N. mirabilis plants revealed the presence of additional BWYV isolates differing by several insertion/deletion mutations in ORF5. PMID:27180098

  19. Herpes Simplex Virus Products in Productive and Abortive Infection

    PubMed Central

    Spring, Susan B.; Roizman, Bernard; Schwartz, Jerome

    1968-01-01

    Herpes simplex virus strain MPdk− multiplies in HEp-2 cells, but not in dog kidney (DK) cells. Strain MPdk+sp, a multistep mutant of MPdk−, multiplies in both HEp-2 and DK cells. Stabilized lysates of productively infected cells yield three macromolecular aggregates of viral deoxyribonucleic acid and protein banding in CsCl gradients at densities of 1.285 g/cm3 (α), 1.325 g/cm3 (β), and 1.37 to 1.45 g/cm3 (γ). Similar lysates from abortively infected cells yield only the β and γ bands. Electron microscopic examination revealed that (i) the α band contained enveloped nucleocapsids, whereas the β band contained naked nucleocapsids and particles tentatively identified as internal components of the nucleocapsids, and that (ii) the enveloped virions and reduplication of cellular membranes observed in thin sections of productively infected cells were absent from abortively infected cells. Studies of the surface antigens of infected cells in a cytolytic system described previously revealed that abortively infected cells contained approximately 10-fold less virus-induced surface antigen than did productively infected cells. From these and other data published previously, we concluded that infectious MPdk− virions are not made in DK cells because (i) functional viral products necessary for the envelopment of the nucleocapsid are not made, and (ii) capsid proteins and some nonstructural products specified by the virus malfunction. Images PMID:4316018

  20. Co-infection of mallards with low virulence Newcastle disease virus and low pathogenic avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Waterfowl are considered the natural reservoirs of low pathogenic avian influenza viruses (LPAIV) and low virulence Newcastle disease viruses (loNDV). The objective of this study was to investigate the effect of co-infections with loNDV and LPAIV on the infectivity and excretion of these viruses in ...

  1. Experimental evidence of hepatitis A virus infection in pigs.

    PubMed

    Song, Young-Jo; Park, Woo-Jung; Park, Byung-Joo; Kwak, Sang-Woo; Kim, Yong-Hyeon; Lee, Joong-Bok; Park, Seung-Yong; Song, Chang-Seon; Lee, Sang-Won; Seo, Kun-Ho; Kang, Young-Sun; Park, Choi-Kyu; Song, Jae-Young; Choi, In-Soo

    2016-04-01

    Hepatitis A virus (HAV) is the leading cause of acute viral hepatitis worldwide, with HAV infection being restricted to humans and nonhuman primates. In this study, HAV infection status was serologically determined in domestic pigs and experimental infections of HAV were attempted to verify HAV infectivity in pigs. Antibodies specific to HAV or HAV-like agents were detected in 3.5% of serum samples collected from pigs in swine farms. When the pigs were infected intravenously with 2 × 10(5) 50% tissue culture infectious dose (TCID50 ) of HAV, shedding of the virus in feces, viremia, and seroconversion were detected. In pigs orally infected with the same quantity of HAV, viral shedding was detected only in feces. HAV genomic RNA was detected in the liver and bile of intravenously infected pigs, but only in the bile of orally infected pigs. In further experiments, pigs were intravenously infected with 6 × 10(5) TCID50 of HAV. Shedding of HAV in feces, along with viremia and seroconversion, were confirmed in infected pigs but not in sentinel pigs. HAV genomic RNA was detected in the liver, bile, spleen, lymph node, and kidney of the infected pigs. HAV antigenomic RNA was detected in the spleen of one HAV-infected pig, suggesting HAV replication in splenic cells. Infiltration of inflammatory cells was observed in the livers of infected pigs but not in controls. This is the first experimental evidence to demonstrate that human HAV strains can infect pigs. PMID:26381440

  2. Adaptive immune response during hepatitis C virus infection

    PubMed Central

    Larrubia, Juan Ramón; Moreno-Cubero, Elia; Lokhande, Megha Uttam; García-Garzón, Silvia; Lázaro, Alicia; Miquel, Joaquín; Perna, Cristian; Sanz-de-Villalobos, Eduardo

    2014-01-01

    Hepatitis C virus (HCV) infection affects about 170 million people worldwide and it is a major cause of liver cirrhosis and hepatocellular carcinoma. HCV is a hepatotropic non-cytopathic virus able to persist in a great percentage of infected hosts due to its ability to escape from the immune control. Liver damage and disease progression during HCV infection are driven by both viral and host factors. Specifically, adaptive immune response carries out an essential task in controlling non-cytopathic viruses because of its ability to recognize infected cells and to destroy them by cytopathic mechanisms and to eliminate the virus by non-cytolytic machinery. HCV is able to impair this response by several means such as developing escape mutations in neutralizing antibodies and in T cell receptor viral epitope recognition sites and inducing HCV-specific cytotoxic T cell anergy and deletion. To impair HCV-specific T cell reactivity, HCV affects effector T cell regulation by modulating T helper and Treg response and by impairing the balance between positive and negative co-stimulatory molecules and between pro- and anti-apoptotic proteins. In this review, the role of adaptive immune response in controlling HCV infection and the HCV mechanisms to evade this response are reviewed. PMID:24707125

  3. Inactivation of the MAPK signaling pathway by Listeria monocytogenes infection promotes trophoblast giant cell death

    PubMed Central

    Hashino, Masanori; Tachibana, Masato; Nishida, Takashi; Hara, Hideki; Tsuchiya, Kohsuke; Mitsuyama, Masao; Watanabe, Kenta; Shimizu, Takashi; Watarai, Masahisa

    2015-01-01

    Listeria monocytogenes has a well-characterized ability to cross the placental barrier, resulting in spontaneous abortion and fetal infections. However, the mechanisms resulting in infection-associated abortion are not fully understood. In this study, we demonstrate that the dephosphorylation of MAPK family proteins caused by L. monocytogenes infection of trophoblast giant (TG) cells, which are placental immune cells, contributes to infectious abortion. Dephosphorylation of c-Jun, p38, and ERK1/2 was observed in infected TG cells, causing the downregulation of cytoprotective heme oxygenase (HO)-1. Blocking the dephosphorylation of proteins, including MAPK family proteins, inhibited the decrease in HO-1 expression. Treatment with MAPK inhibitors inhibited bacterial internalization into TG cells. Moreover, Toll-like receptor 2 involved in the expression of MAPK family proteins. Infection with a listeriolysin O-deleted mutant impaired dephosphorylation of MAPK family proteins in TG cells and did not induce infectious abortion in a mouse model. These results suggest that inactivation of the MAPK pathway by L. monocytogenes induces TG cell death and causes infectious abortion. PMID:26528279

  4. Inhibition of apoptosis in human immunodeficiency virus-infected cells enhances virus production and facilitates persistent infection.

    PubMed Central

    Antoni, B A; Sabbatini, P; Rabson, A B; White, E

    1995-01-01

    Apoptosis is one of several mechanisms by which human immunodeficiency virus type 1 (HIV-1) exerts its cytopathic effects. CD4+ Jurkat T-cell lines overexpressing the adenovirus E1B 19K protein, a potent inhibitor of apoptosis, were used to examine the consequences of inhibition of apoptosis during acute and chronic HIV-1 infections. E1B 19K protein expression inhibited HIV-induced apoptosis, enhanced virus production, and established high levels of persistent viral infection. One E1B 19K-expressing line appeared to undergo HIV-induced death via a nonapoptotic mechanism, illustrating that HIV infection results in lymphocyte depletion through multiple pathways. Increased virus production associated with sustained cell viability suggests that therapeutic approaches involving inhibition of HIV-induced programmed cell death may be problematic. PMID:7884884

  5. Experimental Infection of Horses with West Nile virus

    PubMed Central

    Bowen, Richard A.; Cropp, Bruce C.; Sullivan, Kevin G.; Davis, Brent S.; Komar, Nieholas; Godsey, Marvin; Baker, Dale; Hettler, Danielle L.; Holmes, Derek A.; Biggerstaff, Brad J.; Mitchell, Carl J.

    2002-01-01

    A total of 12 horses of different breeds and ages were infected with West Nile virus (WNV) via the bites of infected Aedes albopictus mosquitoes. Half the horses were infected with a viral isolate from the brain of a horse (BC787), and half were infected with an isolate from crow brain (NY99-6625); both were NY99 isolates. Postinfection, uninfected female Ae. albopictus fed on eight of the infected horses. In the first trial, Nt antibody titers reached >1:320, 1:20, 1:160, and 1:80 for horses 1 to 4, respectively. In the second trial, the seven horses with subclinical infections developed Nt antibody titers >1:10 between days 7 and 11 post infection. The highest viremia level in horses fed upon by the recipient mosquitoes was approximately 460 Vero cell PFU/mL. All mosquitoes that fed upon viremic horses were negative for the virus. Horses infected with the NY99 strain of WNV develop low viremia levels of short duration; therefore, infected horses are unlikely to serve as important amplifying hosts for WNV in nature. PMID:11971771

  6. Microglial activation induces neuronal death in Chandipura virus infection

    PubMed Central

    Verma, Abhishek Kumar; Ghosh, Sourish; Pradhan, Sreeparna; Basu, Anirban

    2016-01-01

    Neurotropic viruses induce neurodegeneration either directly by activating host death domains or indirectly through host immune response pathways. Chandipura Virus (CHPV) belonging to family Rhabdoviridae is ranked among the emerging pathogens of the Indian subcontinent. Previously we have reported that CHPV induces neurodegeneration albeit the root cause of this degeneration is still an open question. In this study we explored the role of microglia following CHPV infection. Phenotypic analysis of microglia through lectin and Iba-1 staining indicated cells were in an activated state post CHPV infection in cortical region of the infected mouse brain. Cytokine Bead Array (CBA) analysis revealed comparatively higher cytokine and chemokine levels in the same region. Increased level of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), Nitric Oxide (NO) and Reactive Oxygen species (ROS) in CHPV infected mouse brain indicated a strong inflammatory response to CHPV infection. Hence it was hypothesized through our analyses that this inflammatory response may stimulate the neuronal death following CHPV infection. In order to validate our hypothesis supernatant from CHPV infected microglial culture was used to infect neuronal cell line and primary neurons. This study confirmed the bystander killing of neurons due to activation of microglia post CHPV infection. PMID:26931456

  7. New perspectives for preventing hepatitis C virus liver graft infection.

    PubMed

    Felmlee, Daniel J; Coilly, Audrey; Chung, Raymond T; Samuel, Didier; Baumert, Thomas F

    2016-06-01

    Hepatitis C virus (HCV) infection is a leading cause of end-stage liver disease that necessitates liver transplantation. The incidence of virus-induced cirrhosis and hepatocellular carcinoma continues to increase, making liver transplantation increasingly common. Infection of the engrafted liver is universal and accelerates progression to advanced liver disease, with 20-30% of patients having cirrhosis within 5 years of transplantation. Treatments of chronic HCV infection have improved dramatically, albeit with remaining challenges of failure and access, and therapeutic options to prevent graft infection during liver transplantation are emerging. Developments in directed use of new direct-acting antiviral agents (DAAs) to eliminate circulating HCV before or after transplantation in the past 5 years provide renewed hope for prevention and treatment of liver graft infection. Identification of the ideal regimen and use of DAAs reveals new ways to treat this specific population of patients. Complementing DAAs, viral entry inhibitors have been shown to prevent liver graft infection in animal models and delay graft infection in clinical trials, which shows their potential for use concomitant to transplantation. We review the challenges and pathology associated with HCV liver graft infection, highlight current and future strategies of DAA treatment timing, and discuss the potential role of entry inhibitors that might be used synergistically with DAAs to prevent or treat graft infection. PMID:27301929

  8. Natural History of Primary Epstein-Barr Virus Infection in Children of Mothers Infected with Human Immunodeficiency Virus Type 1

    PubMed Central

    Jenson, Hal; McIntosh, Kenneth; Pitt, Jane; Husak, Scott; Tan, Ming; Bryson, Yvonne; Easley, Kirk

    2015-01-01

    The natural history of Epstein-Barr virus (EBV) infection in 556 infants born to 517 human immunodeficiency virus (HIV) type 1–infected mothers was studied in a prospective, multicenter, cohort study. HIV-1–infected children had a cumulative EBV infection rate similar to HIV-1–uninfected children at age 3 years (77.8% vs. 84.9%) but had more frequent oropharyngeal EBV shedding (50.4% vs. 28.2%; P < .001). The probability of shedding decreased with longer time from EBV seroconversion and was similar to that of HIV-1–uninfected children 3 years after seroconversion. HIV-1–infected children identified as rapid progressors shed EBV more frequently than nonrapid progressors (69.4% vs.41.0%; P = .01). HIV-1–infected children with EBV infection had higher mean CD8 cell counts. EBV infection did not have an independent effect on mean CD4 cell counts, percent CD4, IgG levels, HIV-1 RNA levels, lymphadenopathy, hepatomegaly, or splenomegaly. Early EBV infection is common in children born to HIV-1–infected mothers. Children with rapidly progressive HIV-1 disease have more frequent EBV shedding. PMID:10228060

  9. Chromatin assembly on herpes simplex virus genomes during lytic infection

    PubMed Central

    Lu, Xu; Triezenberg, Steven J

    2009-01-01

    The human herpes simplex viruses HSV-1 and HSV-2 infect a significant portion of the human population. Both viruses can undergo lytic infection in epithelial cells and establish lifelong latency in neuronal cells. The large HSV-1 DNA genomes have long been considered to be devoid of histones both inside the virion particle and inside the cell during lytic infection, but to be packaged in repressive chromatin during latency. However, recent reports indicate that many histone and non-histone chromosomal proteins can associate with viral DNA during lytic infection and may influence important events during the HSV-1 lytic cycle. In this article, we summarize recent developments in this field and their implications. PMID:19682614

  10. [HIV infection and parenteral virus hepatitis in the Krasnodar territory].

    PubMed

    Larin, F I; Lebedev, V V; Red'ko, A N

    2005-01-01

    The analysis of the morbidity dynamics of HIV infection, hepatitis B and C in the Krasnodar territory for 1996-2003 is presented. The tendency of strengthening direct correlation between age-dependent rates in these groups of diseases has been established. The correlation coefficient (rxy) is at present +0.851 (HIV infection-virus hepatitis B) and +0.892 (HIV infection-virus hepatitis C). The highest levels of primary morbidity are registered in persons aged 20-39 years. The established epidemiological parallels between HIV infection and parenteral hepatitis require the development of the unified strategy of the prophylaxis of these diseases on the federal and regional levels. PMID:16028521

  11. Influenza A Virus Infection, Innate Immunity, and Childhood

    PubMed Central

    Coates, Bria M.; Staricha, Kelly L.; Wiese, Kristin M.; Ridge, Karen M.

    2016-01-01

    Infection with influenza A virus is responsible for considerable morbidity and mortality in children worldwide. While it is apparent that adequate activation of the innate immune system is essential for pathogen clearance and host survival, an excessive inflammatory response to infection is detrimental to the young host. A review of the literature indicates that innate immune responses change throughout childhood. Whether these changes are genetically programmed or triggered by environmental cues is unknown. The objectives of this review are to summarize the role of innate immunity in influenza A virus infection in the young child and to highlight possible differences between children and adults that may make children more susceptible to severe influenza A infection. A better understanding of age-related differences in innate immune signaling will be essential to improve care for this high-risk population. PMID:26237589

  12. Transcriptome analysis of feline infectious peritonitis virus infection.

    PubMed

    Mehrbod, Parvaneh; Harun, Mohammad Syamsul Reza; Shuid, Ahmad Naqib; Omar, Abdul Rahman

    2015-01-01

    Feline infectious peritonitis (FIP) is a lethal systemic disease caused by FIP virus (FIPV). There are no effective vaccines or treatment available, and the virus virulence determinants and pathogenesis are not fully understood. Here, we describe the sequencing of RNA extracted from Crandell Rees Feline Kidney (CRFK) cells infected with FIPV using the Illumina next-generation sequencing approach. Bioinformatics analysis, based on Felis catus 2X annotated shotgun reference genome, using CLC bio Genome Workbench is used to map both control and infected cells. Kal's Z test statistical analysis is used to analyze the differentially expressed genes from the infected CRFK cells. In addition, RT-qPCR analysis is used for further transcriptional profiling of selected genes in infected CRFK cells and Peripheral Blood Mononuclear Cells (PBMCs) from healthy and FIP-diagnosed cats. PMID:25720485

  13. Fatal Cowpox Virus Infection in an Aborted Foal.

    PubMed

    Franke, Annika; Kershaw, Olivia; Jenckel, Maria; König, Lydia; Beer, Martin; Hoffmann, Bernd; Hoffmann, Donata

    2016-06-01

    The article describes the isolation of a cowpox virus (CPXV) isolate originating from a horse. The skin of a foal, aborted in the third trimester, displayed numerous cutaneous papules. The histological examination showed A-type inclusion bodies within the lesion, typical for CPXV infections. This suspicion was confirmed by real-time PCR where various organs were analyzed. From skin samples, virus isolation was successfully performed. Afterwards, the whole genome of this new isolate "CPXV Amadeus" was sequenced by next-generation technology. Phylogenetic analysis clearly showed that "CPXV Amadeus" belongs to the "CPXV-like 1" clade. To our opinion, the study provides important additional information on rare accidental CPXV infections. From the natural hosts, the voles, species such as rats, cats, or different zoo animals are occasionally infected, but until now only two horse cases are described. In addition, there are new insights toward congenital CPXV infections. PMID:27159333

  14. PRRSV receptors and their roles in virus infection.

    PubMed

    Shi, Chongxu; Liu, Yali; Ding, Yaozhong; Zhang, Yongguang; Zhang, Jie

    2015-05-01

    Porcine reproductive and respiratory syndrome virus (PRRSV) has a restricted cell tropism and prefers to invade well-differentiated cells of the monocyte/macrophage lineage, such as pulmonary alveolar macrophages and African green monkey kidney cell line MA-104 and its derivatives, such as Marc-145, Vero and CL-2621. PRRSV infection of the host cells actually is a receptor-mediated endocytosis and replication process. The presence and absence of the cellular receptors decide whether the cell lines are permissive or non-permissive to PRRSV infection. Several PRRSV non-permissive cell lines, such as BHK-21, PK-15 and CHO-K1, have been shown to become sensitive to the virus infection upon expression of the recombinant receptor proteins. Up to now, heparin sulfate, sialoadhesin, CD163, CD151 and vimentin have been identified as the important PRRSV receptors via their involvement in virus attachment, internalization or uncoating. Each receptor is characterized by the distribution in different cells, the function in virus different infection stages and the interaction model with the viral proteins or genes. Joint forces of the receptors recently attract attentions due to the specific function. PRRSV receptors have become the targets for designing the new anti-viral reagents or the recombinant cell lines used for isolating the viruses or developing more effective vaccines due to their more conserved sequences compared with the genetic variation of the virus. In this paper, the role of PRRSV receptors and the molecular mechanism of the interaction between the virus and the receptors are reviewed. PMID:25666932

  15. Macrophages in Progressive Human Immunodeficiency Virus/Simian Immunodeficiency Virus Infections.

    PubMed

    DiNapoli, Sarah R; Hirsch, Vanessa M; Brenchley, Jason M

    2016-09-01

    The cells that are targeted by primate lentiviruses (HIV and simian immunodeficiency virus [SIV]) are of intense interest given the renewed effort to identify potential cures for HIV. These viruses have been reported to infect multiple cell lineages of hematopoietic origin, including all phenotypic and functional CD4 T cell subsets. The two most commonly reported cell types that become infected in vivo are memory CD4 T cells and tissue-resident macrophages. Though viral infection of CD4 T cells is routinely detected in both HIV-infected humans and SIV-infected Asian macaques, significant viral infection of macrophages is only routinely observed in animal models wherein CD4 T cells are almost entirely depleted. Here we review the roles of macrophages in lentiviral disease progression, the evidence that macrophages support viral replication in vivo, the animal models where macrophage-mediated replication of SIV is thought to occur, how the virus can interact with macrophages in vivo, pathologies thought to be attributed to viral replication within macrophages, how viral replication in macrophages might contribute to the asymptomatic phase of HIV/SIV infection, and whether macrophages represent a long-lived reservoir for the virus. PMID:27307568

  16. Giant magnetoimpedance-based microchannel system for quick and parallel genotyping of human papilloma virus type 16/18

    NASA Astrophysics Data System (ADS)

    Yang, Hao; Chen, Lei; Lei, Chong; Zhang, Ju; Li, Ding; Zhou, Zhi-Min; Bao, Chen-Chen; Hu, Heng-Yao; Chen, Xiang; Cui, Feng; Zhang, Shuang-Xi; Zhou, Yong; Cui, Da-Xiang

    2010-07-01

    Quick and parallel genotyping of human papilloma virus (HPV) type 16/18 is carried out by a specially designed giant magnetoimpedance (GMI) based microchannel system. Micropatterned soft magnetic ribbon exhibiting large GMI ratio serves as the biosensor element. HPV genotyping can be determined by the changes in GMI ratio in corresponding detection region after hybridization. The result shows that this system has great potential in future clinical diagnostics and can be easily extended to other biomedical applications based on molecular recognition.

  17. Neuromuscular complications of human immunodeficiency virus infection and antiretroviral therapy.

    PubMed Central

    Miller, R G

    1994-01-01

    At least 4 distinct peripheral neuropathy syndromes occur in patients infected with the human immunodeficiency virus. The most common, painful sensory neuropathy, may be related to the viral infection or may be medication induced and is treated symptomatically. The other 3, chronic inflammatory demyelinating polyradiculoneuropathy, mononeuropathy multiplex (some patients), and the progressive polyradiculopathies related to the acquired immunodeficiency syndrome, may all respond to appropriate therapy. Both inflammatory myopathy and zidovudine myopathy also abate with early diagnosis and treatment. PMID:8048229

  18. Previous infection with a mesogenic strain of newcastle disease virus prevents infection with a highly pathogenic avian influenza virus in chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus (AIV) and Newcastle disease virus (NDV) are two of the most important viruses affecting poultry worldwide. Co-infections of poultry with AIV and NDV are a problem from both the clinical point of view and the diagnosis of these viruses, but little is known on the interactions b...

  19. Experimental infection of vertebrates of the Pocomoke Cypress Swamp, Maryland with Keystone and Jamestown Canyon viruses.

    PubMed

    Watts, D M; Tammariello, R F; Dalrymple, J M; Eldridge, B F; Russell, P K; Top, F H

    1979-03-01

    Experimental studies were conducted to assess the susceptibility of white-tailed deer (Odocoileus virginianus), gray squirrels (Sciurus carolinensis), and cottontail rabbits (Sylvilagus floridanus) to Jamestown Canyon (JC) and/or Keystone (KEY) virus infection. Viremia occurred in 5 of 6 deer inoculated with JC virus; however, all deer developed KEY virus neutralizing antibody. Based on the observation that antibody elicited by primary infection of deer with either KEY or JC virus exhibited partial heterologous neutralization in vitro, cross-challenge experiments were performed in these animals. Keystone virus failed to infect deer 30 days post primary JC virus infection; however, deer became infected when challenged with KEY virus 80 days after the initial JC virus infection as indicated by a substantial increase in antibody titer. Similarly, JC virus failed to produce viremia in immune animals infected with KEY virus 80 days previously, although 2 of the 3 animals challenged had serological evidence of infection. Three field-collected cottontail rabbits with no evidence of KEY antibody were readily susceptible to KEY virus infection and developed viremias of 1-4 days' duration; rabbits with KEY virus antibody did not develop viremia upon KEY virus challenge. Eight antibody-negative field-collected gray squirrels became viremic following injection with KEY virus; however, a comparable group of squirrels did not become viremic when injected with JC virus. PMID:453437

  20. The role of IKKβ in Venezuelan equine encephalitis virus infection.

    PubMed

    Amaya, Moushimi; Voss, Kelsey; Sampey, Gavin; Senina, Svetlana; de la Fuente, Cynthia; Mueller, Claudius; Calvert, Valerie; Kehn-Hall, Kylene; Carpenter, Calvin; Kashanchi, Fatah; Bailey, Charles; Mogelsvang, Soren; Petricoin, Emanuel; Narayanan, Aarthi

    2014-01-01

    Venezuelan equine encephalitis virus (VEEV) belongs to the genus Alphavirus, family Togaviridae. VEEV infection is characterized by extensive inflammation and studies from other laboratories implicated an involvement of the NF-κB cascade in the in vivo pathology. Initial studies indicated that at early time points of VEEV infection, the NF-κB complex was activated in cells infected with the TC-83 strain of VEEV. One upstream kinase that contributes to the phosphorylation of p65 is the IKKβ component of the IKK complex. Our previous studies with Rift valley fever virus, which exhibited early activation of the NF-κB cascade in infected cells, had indicated that the IKKβ component underwent macromolecular reorganization to form a novel low molecular weight form unique to infected cells. This prompted us to investigate if the IKK complex undergoes a comparable macromolecular reorganization in VEEV infection. Size-fractionated VEEV infected cell extracts indicated a macromolecular reorganization of IKKβ in VEEV infected cells that resulted in formation of lower molecular weight complexes. Well-documented inhibitors of IKKβ function, BAY-11-7082, BAY-11-7085 and IKK2 compound IV, were employed to determine whether IKKβ function was required for the production of infectious progeny virus. A decrease in infectious viral particles and viral RNA copies was observed with inhibitor treatment in the attenuated and virulent strains of VEEV infection. In order to further validate the requirement of IKKβ for VEEV replication, we over-expressed IKKβ in cells and observed an increase in viral titers. In contrast, studies carried out using IKKβ(-/-) cells demonstrated a decrease in VEEV replication. In vivo studies demonstrated that inhibitor treatment of TC-83 infected mice increased their survival. Finally, proteomics studies have revealed that IKKβ may interact with the viral protein nsP3. In conclusion, our studies have revealed that the host IKKβ protein may be

  1. The Role of IKKβ in Venezuelan Equine Encephalitis Virus Infection

    PubMed Central

    Amaya, Moushimi; Voss, Kelsey; Sampey, Gavin; Senina, Svetlana; de la Fuente, Cynthia; Mueller, Claudius; Calvert, Valerie; Kehn-Hall, Kylene; Carpenter, Calvin; Kashanchi, Fatah; Bailey, Charles; Mogelsvang, Soren; Petricoin, Emanuel; Narayanan, Aarthi

    2014-01-01

    Venezuelan equine encephalitis virus (VEEV) belongs to the genus Alphavirus, family Togaviridae. VEEV infection is characterized by extensive inflammation and studies from other laboratories implicated an involvement of the NF-κB cascade in the in vivo pathology. Initial studies indicated that at early time points of VEEV infection, the NF-κB complex was activated in cells infected with the TC-83 strain of VEEV. One upstream kinase that contributes to the phosphorylation of p65 is the IKKβ component of the IKK complex. Our previous studies with Rift valley fever virus, which exhibited early activation of the NF-κB cascade in infected cells, had indicated that the IKKβ component underwent macromolecular reorganization to form a novel low molecular weight form unique to infected cells. This prompted us to investigate if the IKK complex undergoes a comparable macromolecular reorganization in VEEV infection. Size-fractionated VEEV infected cell extracts indicated a macromolecular reorganization of IKKβ in VEEV infected cells that resulted in formation of lower molecular weight complexes. Well-documented inhibitors of IKKβ function, BAY-11-7082, BAY-11-7085 and IKK2 compound IV, were employed to determine whether IKKβ function was required for the production of infectious progeny virus. A decrease in infectious viral particles and viral RNA copies was observed with inhibitor treatment in the attenuated and virulent strains of VEEV infection. In order to further validate the requirement of IKKβ for VEEV replication, we over-expressed IKKβ in cells and observed an increase in viral titers. In contrast, studies carried out using IKKβ−/− cells demonstrated a decrease in VEEV replication. In vivo studies demonstrated that inhibitor treatment of TC-83 infected mice increased their survival. Finally, proteomics studies have revealed that IKKβ may interact with the viral protein nsP3. In conclusion, our studies have revealed that the host IKKβ protein may be

  2. Hepatitis E virus infection--a new threat for Europe.

    PubMed

    Łapiński, Tadeusz Wojciech; Jaroszewicz, Jerzy

    2016-01-01

    Of 20 million of patients infected with hepatitis E virus (HEV) worldwide 57 thousand dies each year. HEV-infection is not longer regarded as a diseases in developing endemic countries of Asia, Africa and Latin America. The majority of European countries faces increasing number of endemic infections. They are caused by seven different genotypes and be responsible for acute and chronic infections. HEV is of zoonotic origin causing infections in pigs and boars which are a source of infection for humans. Infections occur orally after consumption of infected water or meat. HEV-infection is most dangerous for patients receiving immunosuppressive therapy, infected with HIV, after transplantations of solid organs and elderly. In some patients, including pregnant women, acute HEV has a serious course with fatalities reaching even 25%. Chronic HEV-infection may develop in patients following solid organ transplantations and requires long-term antiviral therapy. HEV-infection is a growing public health problem in Europe, which implies the necessity of routine screening in selected populations, especially immunocompromised. PMID:27344467

  3. Alteration of cell cycle progression by Sindbis virus infection

    SciTech Connect

    Yi, Ruirong; Saito, Kengo; Isegawa, Naohisa; Shirasawa, Hiroshi

    2015-07-10

    We examined the impact of Sindbis virus (SINV) infection on cell cycle progression in a cancer cell line, HeLa, and a non-cancerous cell line, Vero. Cell cycle analyses showed that SINV infection is able to alter the cell cycle progression in both HeLa and Vero cells, but differently, especially during the early stage of infection. SINV infection affected the expression of several cell cycle regulators (CDK4, CDK6, cyclin E, p21, cyclin A and cyclin B) in HeLa cells and caused HeLa cells to accumulate in S phase during the early stage of infection. Monitoring SINV replication in HeLa and Vero cells expressing cell cycle indicators revealed that SINV which infected HeLa cells during G{sub 1} phase preferred to proliferate during S/G{sub 2} phase, and the average time interval for viral replication was significantly shorter in both HeLa and Vero cells infected during G{sub 1} phase than in cells infected during S/G{sub 2} phase. - Highlights: • SINV infection was able to alter the cell cycle progression of infected cancer cells. • SINV infection can affect the expression of cell cycle regulators. • SINV infection exhibited a preference for the timing of viral replication among the cell cycle phases.

  4. The Effects of High Temperature on Infection by Potato virus Y, Potato virus A, and Potato leafroll virus.

    PubMed

    Chung, Bong Nam; Canto, Tomas; Tenllado, Francisco; Choi, Kyung San; Joa, Jae Ho; Ahn, Jeong Joon; Kim, Chun Hwan; Do, Ki Seck

    2016-08-01

    We examined the effects of temperature on acquisition of Potato virus Y-O (PVY-O), Potato virus A (PVA), and Potato leafroll virus (PLRV) by Myzus persicae by performing transmission tests with aphids that acquired each virus at different temperatures. Infection by PVY-O/PVA and PLRV increased with increasing plant temperature in Nicotiana benthamiana and Physalis floridana, respectively, after being transmitted by aphids that acquired them within a temperature range of 10-20°C. However, infection rates subsequently decreased. Direct qRT-PCR of RNA extracted from a single aphid showed that PLRV infection increased in the 10-20°C range, but this trend also declined shortly thereafter. We examined the effect of temperature on establishment of virus infection. The greatest number of plants became infected when N. benthamiana was held at 20°C after inoculation with PVY-O or PVA. The largest number of P. floridana plants became infected with PLRV when the plants were maintained at 25°C. PLRV levels were highest in P. floridana kept at 20-25°C. These results indicate that the optimum temperatures for proliferation of PVY-O/PVA and PLRV differed. Western blot analysis showed that accumulations of PVY-O and PVA coat proteins (CPs) were lower at 10°C or 15°C than at 20°C during early infection. However, accumulation increased over time. At 25°C or 30°C, the CPs of both viruses accumulated during early infection but disappeared as time passed. Our results suggest that symptom attenuation and reduction of PVY-O and PVA CP accumulation at higher temperatures appear to be attributable to increased RNA silencing. PMID:27493607

  5. The Effects of High Temperature on Infection by Potato virus Y, Potato virus A, and Potato leafroll virus

    PubMed Central

    Chung, Bong Nam; Canto, Tomas; Tenllado, Francisco; Choi, Kyung San; Joa, Jae Ho; Ahn, Jeong Joon; Kim, Chun Hwan; Do, Ki Seck

    2016-01-01

    We examined the effects of temperature on acquisition of Potato virus Y-O (PVY-O), Potato virus A (PVA), and Potato leafroll virus (PLRV) by Myzus persicae by performing transmission tests with aphids that acquired each virus at different temperatures. Infection by PVY-O/PVA and PLRV increased with increasing plant temperature in Nicotiana benthamiana and Physalis floridana, respectively, after being transmitted by aphids that acquired them within a temperature range of 10–20°C. However, infection rates subsequently decreased. Direct qRT-PCR of RNA extracted from a single aphid showed that PLRV infection increased in the 10–20°C range, but this trend also declined shortly thereafter. We examined the effect of temperature on establishment of virus infection. The greatest number of plants became infected when N. benthamiana was held at 20°C after inoculation with PVY-O or PVA. The largest number of P. floridana plants became infected with PLRV when the plants were maintained at 25°C. PLRV levels were highest in P. floridana kept at 20–25°C. These results indicate that the optimum temperatures for proliferation of PVY-O/PVA and PLRV differed. Western blot analysis showed that accumulations of PVY-O and PVA coat proteins (CPs) were lower at 10°C or 15°C than at 20°C during early infection. However, accumulation increased over time. At 25°C or 30°C, the CPs of both viruses accumulated during early infection but disappeared as time passed. Our results suggest that symptom attenuation and reduction of PVY-O and PVA CP accumulation at higher temperatures appear to be attributable to increased RNA silencing. PMID:27493607

  6. Host sphingomyelin increases West Nile virus infection in vivo.

    PubMed

    Martín-Acebes, Miguel A; Gabandé-Rodríguez, Enrique; García-Cabrero, Ana M; Sánchez, Marina P; Ledesma, María Dolores; Sobrino, Francisco; Saiz, Juan-Carlos

    2016-03-01

    Flaviviruses, such as the dengue virus and the West Nile virus (WNV), are arthropod-borne viruses that represent a global health problem. The flavivirus lifecycle is intimately connected to cellular lipids. Among the lipids co-opted by flaviviruses, we have focused on SM, an important component of cellular membranes particularly enriched in the nervous system. After infection with the neurotropic WNV, mice deficient in acid sphingomyelinase (ASM), which accumulate high levels of SM in their tissues, displayed exacerbated infection. In addition, WNV multiplication was enhanced in cells from human patients with Niemann-Pick type A, a disease caused by a deficiency of ASM activity resulting in SM accumulation. Furthermore, the addition of SM to cultured cells also increased WNV infection, whereas treatment with pharmacological inhibitors of SM synthesis reduced WNV infection. Confocal microscopy analyses confirmed the association of SM with viral replication sites within infected cells. Our results unveil that SM metabolism regulates flavivirus infection in vivo and propose SM as a suitable target for antiviral design against WNV. PMID:26764042

  7. Epstein-Barr Virus Induced Epigenetic Alterations Following Transient Infection

    PubMed Central

    Queen, Krista J.; Shi, Mingxia; Zhang, Fangfang; Cvek, Urska; Scott, Rona S.

    2012-01-01

    Epstein-Barr virus (EBV) is a known tumor virus associated with an increasing array of malignancies; however, the association of the virus with certain malignancies is often erratic. To determine EBV’s contributions to tumorigenesis in a setting of incomplete association, a transient model of infection was established where a clonal CCL185 carcinoma cell line infected with recombinant EBV was allowed to lose viral genomes by withdrawal of selection pressure. Global gene expression comparing EBV-negative, transiently infected clones to uninfected controls identified expression changes in over 1000 genes. Among downregulated genes, several genes known to be DNA methylated in cancer were identified including E-cadherin and PYCARD. A cadherin switch, increased motility and enhanced cellular invasiveness present in EBV-positive cells were retained following viral loss indicating an epigenetic effect. Repression of PYCARD expression was due to increased promoter CpG methylation, whereas loss of E-cadherin expression after transient EBV infection did not correlate with increased DNA methylation of the E-cadherin promoter. Rather, repression of E-cadherin was consistent with formation of a repressive chromatin state. Decreased histone 3 or 4 acetylation at the promoter and 5’ end of the E-cadherin gene was observed in an EBV-negative, transiently infected clone relative to the uninfected controls. These results suggest that EBV can stably alter gene expression in a heritable fashion in formerly infected cells, while its own contribution to the oncogenic process is masked. PMID:23047626

  8. Induction of apoptosis in frog virus 3-infected cells.

    PubMed

    Chinchar, V G; Bryan, Locke; Wang, J; Long, Scott; Chinchar, G D

    2003-02-15

    The ability of frog virus 3 (FV3), the type species of the family Iridoviridae, to induce apoptosis was examined by monitoring DNA cleavage, chromatin condensation, and cell-surface expression of phosphotidylserine (PS) in fathead minnow (FHM) and baby hamster kidney (BHK) cells. In productively infected FHM cells, DNA fragmentation was first noted at 6-7 h postinfection and was clearly seen by 17 h postinfection, while chromatin condensation was detected at 8.5 h postinfection. As with some other viruses, FV3-induced apoptosis did not require de novo viral gene expression as both heat-inactivated and UV-inactivated virus readily triggered DNA fragmentation in FHM cells. Moreover, FV3-induced apoptosis was blocked in FHM cells by the pan-caspase inhibitor Z-VAD-FMK, suggesting that virus infection triggers programmed cell death through activation of the caspase cascade. FV3 infection also triggered apoptosis in BHK cells as monitored by TUNEL and annexin V binding assays. To determine whether FV3, similar to other large DNA viruses, encoded proteins that block or delay apoptosis, mock- and FV3-infected FHM cells were osmotically shocked and assayed for DNA fragmentation 3 hours later. DNA fragmentation was clearly seen whether or not shocked cells were previously infected with FV3, indicating that infection with FV3 did not block apoptosis induced by osmotic shock in FHM cells. The above results demonstrate that iridoviruses triggered apoptosis and that the induction of programmed cell death did not require viral gene expression. However, it remains to be determined if virion attachment to target cells is sufficient to induce cell death, or if apoptosis is triggered directly or indirectly by one or more virion-associated proteins. PMID:12642103

  9. The hepatitis delta virus and its infection

    SciTech Connect

    Rizzeto, M.; Gerin, J.L.; Purcell, R.H.

    1987-01-01

    This book contains over 50 papers. Some of the titles are: Structure and Replication of the Genome of Hepatitis Delta Virus; Clinical Significance of HDV RNA in HDV Disease; HBV DNA in Delta Chronic Carriers; Prevalance of HBV-DNA Among Anti-Hd Positive Patients; and Characterization of LKM/sub 1/ and LKM/sub 2/ Antigens.

  10. Dobrava-Belgrade Virus Spillover Infections, Germany

    PubMed Central

    Schlegel, Mathias; Klempa, Boris; Auste, Brita; Bemmann, Margrit; Schmidt-Chanasit, Jonas; Büchner, Thomas; Groschup, Martin H.; Meier, Markus; Balkema-Buschmann, Anne; Zoller, Hinrich; Krüger, Detlev H.

    2009-01-01

    We present the molecular identification of Apodemus agrarius (striped field mouse) as reservoir host of the Dobrava-Belgrade virus (DOBV) lineage DOBV-Aa in 3 federal states of Germany. Phylogenetic analyses provided evidence for multiple spillover of DOBV-Aa to A. flavicollis, a crucial prerequisite for host switch and genetic reassortment. PMID:19961690

  11. Potent neutralizing monoclonal antibodies against Ebola virus infection.

    PubMed

    Zhang, Qi; Gui, Miao; Niu, Xuefeng; He, Shihua; Wang, Ruoke; Feng, Yupeng; Kroeker, Andrea; Zuo, Yanan; Wang, Hua; Wang, Ying; Li, Jiade; Li, Chufang; Shi, Yi; Shi, Xuanling; Gao, George F; Xiang, Ye; Qiu, Xiangguo; Chen, Ling; Zhang, Linqi

    2016-01-01

    Ebola virus infections cause a deadly hemorrhagic disease for which no vaccines or therapeutics has received regulatory approval. Here we show isolation of three (Q206, Q314 and Q411) neutralizing monoclonal antibodies (mAbs) against the surface glycoprotein (GP) of Ebola virus identified in West Africa in 2014 through sequential immunization of Chinese rhesus macaques and antigen-specific single B cell sorting. These mAbs demonstrated potent neutralizing activities against both pseudo and live Ebola virus independent of complement. Biochemical, single particle EM, and mutagenesis analysis suggested Q206 and Q411 recognized novel epitopes in the head while Q314 targeted the glycan cap in the GP1 subunit. Q206 and Q411 appeared to influence GP binding to its receptor NPC1. Treatment with these mAbs provided partial but significant protection against disease in a mouse model of Ebola virus infection. These novel mAbs could serve as promising candidates for prophylactic and therapeutic interventions against Ebola virus infection. PMID:27181584

  12. Cyclophilin A protects mice against infection by influenza A virus

    PubMed Central

    Li, Jing; Chen, Can; Wong, Gary; Dong, Wei; Zheng, Weinan; Li, Yun; Sun, Lei; Zhang, Lianfeng; Gao, George F.; Bi, Yuhai; Liu, Wenjun

    2016-01-01

    Our previous studies indicate that Cyclophilin A (CypA) impairs the replication of influenza A virus in vitro. To further evaluate the antiviral functions of CypA and explore its mechanism, transgenic mice with overexpression of CypA by two specific promoters with SPC (CypA-SPC) or CMV (CypA-CMV) were developed. After challenge with the A/WSN/33(H1N1) influenza virus, CypA-SPC and CypA-CMV transgenic mice displayed nearly 2.5- and 3.8-fold stronger disease resistance to virus infection, respectively, compared to wild-type animals. Virus replication, pathological lesions and inflammatory cytokines were substantially reduced in both lines of transgenic mice. In addition, after infection there was an upregulation of genes associated with cell migration, immune function, and organ development; and a downregulation of genes associated with the positive regulation of immune cells and apoptosis in the peritoneal macrophages of CypA-overexpressing transgenic mice (CypA+). These results indicate that CypA is a key modulator of influenza virus resistance in mice, and that CypA+ mice constitutes an important model to study the roles of CypA in the regulation of immune responses and infections. PMID:27354005

  13. Cyclophilin A protects mice against infection by influenza A virus.

    PubMed

    Li, Jing; Chen, Can; Wong, Gary; Dong, Wei; Zheng, Weinan; Li, Yun; Sun, Lei; Zhang, Lianfeng; Gao, George F; Bi, Yuhai; Liu, Wenjun

    2016-01-01

    Our previous studies indicate that Cyclophilin A (CypA) impairs the replication of influenza A virus in vitro. To further evaluate the antiviral functions of CypA and explore its mechanism, transgenic mice with overexpression of CypA by two specific promoters with SPC (CypA-SPC) or CMV (CypA-CMV) were developed. After challenge with the A/WSN/33(H1N1) influenza virus, CypA-SPC and CypA-CMV transgenic mice displayed nearly 2.5- and 3.8-fold stronger disease resistance to virus infection, respectively, compared to wild-type animals. Virus replication, pathological lesions and inflammatory cytokines were substantially reduced in both lines of transgenic mice. In addition, after infection there was an upregulation of genes associated with cell migration, immune function, and organ development; and a downregulation of genes associated with the positive regulation of immune cells and apoptosis in the peritoneal macrophages of CypA-overexpressing transgenic mice (CypA+). These results indicate that CypA is a key modulator of influenza virus resistance in mice, and that CypA+ mice constitutes an important model to study the roles of CypA in the regulation of immune responses and infections. PMID:27354005

  14. Potent neutralizing monoclonal antibodies against Ebola virus infection

    PubMed Central

    Zhang, Qi; Gui, Miao; Niu, Xuefeng; He, Shihua; Wang, Ruoke; Feng, Yupeng; Kroeker, Andrea; Zuo, Yanan; Wang, Hua; Wang, Ying; Li, Jiade; Li, Chufang; Shi, Yi; Shi, Xuanling; Gao, George F.; Xiang, Ye; Qiu, Xiangguo; Chen, Ling; Zhang, Linqi

    2016-01-01

    Ebola virus infections cause a deadly hemorrhagic disease for which no vaccines or therapeutics has received regulatory approval. Here we show isolation of three (Q206, Q314 and Q411) neutralizing monoclonal antibodies (mAbs) against the surface glycoprotein (GP) of Ebola virus identified in West Africa in 2014 through sequential immunization of Chinese rhesus macaques and antigen-specific single B cell sorting. These mAbs demonstrated potent neutralizing activities against both pseudo and live Ebola virus independent of complement. Biochemical, single particle EM, and mutagenesis analysis suggested Q206 and Q411 recognized novel epitopes in the head while Q314 targeted the glycan cap in the GP1 subunit. Q206 and Q411 appeared to influence GP binding to its receptor NPC1. Treatment with these mAbs provided partial but significant protection against disease in a mouse model of Ebola virus infection. These novel mAbs could serve as promising candidates for prophylactic and therapeutic interventions against Ebola virus infection. PMID:27181584

  15. Global Reprogramming of Host SUMOylation during Influenza Virus Infection

    PubMed Central

    Domingues, Patricia; Golebiowski, Filip; Tatham, Michael H.; Lopes, Antonio M.; Taggart, Aislynn; Hay, Ronald T.; Hale, Benjamin G.

    2015-01-01

    Summary Dynamic nuclear SUMO modifications play essential roles in orchestrating cellular responses to proteotoxic stress, DNA damage, and DNA virus infection. Here, we describe a non-canonical host SUMOylation response to the nuclear-replicating RNA pathogen, influenza virus, and identify viral RNA polymerase activity as a major contributor to SUMO proteome remodeling. Using quantitative proteomics to compare stress-induced SUMOylation responses, we reveal that influenza virus infection triggers unique re-targeting of SUMO to 63 host proteins involved in transcription, mRNA processing, RNA quality control, and DNA damage repair. This is paralleled by widespread host deSUMOylation. Depletion screening identified ten virus-induced SUMO targets as potential antiviral factors, including C18orf25 and the SMC5/6 and PAF1 complexes. Mechanistic studies further uncovered a role for SUMOylation of the PAF1 complex component, parafibromin (CDC73), in potentiating antiviral gene expression. Our global characterization of influenza virus-triggered SUMO redistribution provides a proteomic resource to understand host nuclear SUMOylation responses to infection. PMID:26549460

  16. Broadly neutralizing antibodies abrogate established hepatitis C virus infection

    PubMed Central

    de Jong, Ype P.; Dorner, Marcus; Mommersteeg, Michiel C.; Xiao, Jing W.; Balazs, Alejandro B.; Robbins, Justin B.; Winer, Benjamin Y.; Gerges, Sherif; Vega, Kevin; Labitt, Rachael N.; Donovan, Bridget M.; Giang, Erick; Krishnan, Anuradha; Chiriboga, Luis; Charlton, Michael R.; Burton, Dennis R.; Baltimore, David; Law, Mansun; Rice, Charles M.; Ploss, Alexander

    2015-01-01

    Hepatitis C virus (HCV) establishes a chronic infection in the majority of exposed individuals and can cause cirrhosis and hepatocellular carcinoma. The role of antibodies directed against HCV in disease progression is poorly understood. Neutralizing antibodies (nAbs) can prevent HCV infection in vitro and in animal models. However, the effects of nAbs on an established HCV infection are unclear. Here, we demonstrate that three broadly nAbs, AR3A, AR3B and AR4A, delivered with adeno-associated viral (AAV) vectors can confer protection against viral challenge in humanized mice. Furthermore, we provide evidence that nAbs can abrogate an ongoing HCV infection in primary hepatocyte cultures and in a human liver chimeric mouse model. These results showcase a novel therapeutic approach to interfere with HCV infection exploiting a previously unappreciated need for HCV to continuously infect new hepatocytes in order to sustain chronicity. PMID:25232181

  17. Shedding of Hepatitis C Virus in Semen of Human Immunodeficiency Virus-Infected Men

    PubMed Central

    Turner, Samuel S.; Gianella, Sara; Yip, Marcus J-S.; van Seggelen, Wouter O.; Gillies, Robert D.; Foster, Andrew L.; Barbati, Zachary R.; Smith, Davey M.; Fierer, Daniel S.

    2016-01-01

    Background. The epidemic of sexually transmitted hepatitis C virus (HCV) infection among human immunodeficiency virus (HIV)-infected men who have sex with men (MSM) has been documented for over a decade. Despite this, there is no consensus as to the risk factors for sexual acquisition of HCV in these men. Methods. We obtained paired semen and blood samples at 2-week intervals from HIV-infected MSM with recent and chronic HCV infection and quantified HCV in semen. Results. Hepatitis C virus was quantified in 59 semen specimens from 33 men. Hepatitis C virus was shed in 16 (27%) of semen specimens from 11 (33%) of the men. Median HCV viral load (VL) in semen was 1.49 log10 IU/mL. Hepatitis C virus VL in blood was significantly higher at the time of HCV shedding in semen than when HCV shedding in semen was not detected (P = .002). Furthermore, there was a significant correlation between the HCV VL in blood and semen overall (rs = 0.41; P = .001), and in the subgroup with recent HCV infection (rs = 0.37; P = .02), but not in the subgroup with chronic HCV infection (rs = 0.34; P = .1). Conclusions. One third of HIV-infected MSM coinfected with HCV shed HCV into their semen. Based on the HCV VL in semen in this study, an average ejaculate would deliver up to 6630 IU of virus into the rectum of the receptive partner. Therefore, our data strongly support that condoms should be used during anal intercourse among MSM to prevent transmission of HCV. PMID:27186582

  18. Prevalence of Hepatitis B Virus Infection in Kenya, 2007.

    PubMed

    Ly, Kathleen N; Kim, Andrea A; Umuro, Mamo; Drobenuic, Jan; Williamson, John M; Montgomery, Joel M; Fields, Barry S; Teshale, Eyasu H

    2016-08-01

    Current estimates put the prevalence of hepatitis B virus (HBV) infection in Kenya at 5-8%. We determined the HBV infection prevalence in the human immunodeficiency virus (HIV)-negative Kenyan adult and adolescent population based on samples collected from a national survey. We analyzed data from HIV-negative participants in the 2007 Kenya AIDS Indicator Survey to estimate the HBV infection prevalence. We defined past or present HBV infection as presence of total hepatitis B core antibody (HBcAb), and chronic HBV infection (CHBI) as presence of both total HBcAb and hepatitis B surface antigen (HBsAg). We calculated crude and adjusted odds of HBV infection by demographic characteristics and risk factors using logistic regression analyses. Of 1,091 participants aged 15-64 years, approximately 31.5% (95% confidence interval [CI] = 28.0-35.3%) had exposure to HBV, corresponding to approximately 6.1 million (CI = 5.4-6.8 million) with past or present HBV infection. The estimated prevalence of CHBI was 2.1% (95% CI = 1.4-3.1%), corresponding to approximately 398,000 (CI = 261,000-602,000) with CHBI. CHBI is a major public health problem in Kenya, affecting approximately 400,000 persons. Knowing the HBV infection prevalence at baseline is important for planning and public health policy decision making and for monitoring the impact of viral hepatitis prevention programs. PMID:27273644

  19. Tissue culture system for infection with human hepatitis delta virus.

    PubMed Central

    Sureau, C; Jacob, J R; Eichberg, J W; Lanford, R E

    1991-01-01

    An in vitro culture system was developed for assaying the infectivity of the human hepatitis delta virus (HDV). Hepatocytes were isolated from chimpanzee liver and grown in a serum-free medium. Cells were shown to be infectible by HDV and to remain susceptible to infection for at least 3 weeks in culture, as evidenced by the appearance of RNA species characteristic of HDV replication as early as 6 days postinfection. When repeated experiments were carried out on cells derived from an animal free of hepatitis B virus (HBV), HDV infection occurred in a consistent fashion but there was no indication of infection with the HBV that was present in the inoculum. Despite numerous attempts with different sources of HBV inocula free of HDV, there was no evidence that indicated susceptibility of these cells to HBV infection. This observation may indicate that HBV and HDV use different modes of entry into hepatocytes. When cells derived from an HBV-infected animal were exposed to HDV, synthesis and release of progeny HDV particles were obtained in addition to HBV replication and production of Dane particles. Although not infectible with HBV, primary cultures of chimpanzee hepatocytes are capable of supporting part of the life cycle of HBV and the entire life cycle of HDV. Images PMID:2041075

  20. Persistent Infection with Ebola Virus under Conditions of Partial Immunity

    PubMed Central

    Gupta, Manisha; Mahanty, Siddhartha; Greer, Patricia; Towner, Jonathan S.; Shieh, Wun-Ju; Zaki, Sherif R.; Ahmed, Rafi; Rollin, Pierre E.

    2004-01-01

    Ebola hemorrhagic fever in humans is associated with high mortality; however, some infected hosts clear the virus and recover. The mechanisms by which this occurs and the correlates of protective immunity are not well defined. Using a mouse model, we determined the role of the immune system in clearance of and protection against Ebola virus. All CD8 T-cell-deficient mice succumbed to subcutaneous infection and had high viral antigen titers in tissues, whereas mice deficient in B cells or CD4 T cells cleared infection and survived, suggesting that CD8 T cells, independent of CD4 T cells and antibodies, are critical to protection against subcutaneous Ebola virus infection. B-cell-deficient mice that survived the primary subcutaneous infection (vaccinated mice) transiently depleted or not depleted of CD4 T cells also survived lethal intraperitoneal rechallenge for ≥25 days. However, all vaccinated B-cell-deficient mice depleted of CD8 T cells had high viral antigen titers in tissues following intraperitoneal rechallenge and died within 6 days, suggesting that memory CD8 T cells by themselves can protect mice from early death. Surprisingly, vaccinated B-cell-deficient mice, after initially clearing the infection, were found to have viral antigens in tissues later (day 120 to 150 post-intraperitoneal infection). Furthermore, following intraperitoneal rechallenge, vaccinated B-cell-deficient mice that were transiently depleted of CD4 T cells had high levels of viral antigen in tissues earlier (days 50 to 70) than vaccinated undepleted mice. This demonstrates that under certain immunodeficiency conditions, Ebola virus can persist and that loss of primed CD4 T cells accelerates the course of persistent infections. These data show that CD8 T cells play an important role in protection against acute disease, while both CD4 T cells and antibodies are required for long-term protection, and they provide evidence of persistent infection by Ebola virus suggesting that under

  1. Spatial Analysis of Feline Immunodeficiency Virus Infection in Cougars

    PubMed Central

    Wheeler, David C.; Waller, Lance A.; Biek, Roman

    2010-01-01

    The cougar (Puma concolor) is a large predatory feline found widely in the Americas that is susceptible to feline immunodeficiency virus (FIV), a fast-evolving lentivirus found in wild feline species that is analogous to simian immunodeficiency viruses in wild primates and belongs to the same family of viruses as human immunodeficiency virus. FIV infection in cougars can lead to a weakened immune system that creates opportunities for other infecting agents. FIV prevalence and lineages have been studied previously in several areas in the western United States, but typically without spatially explicit statistical techniques. To describe the distribution of FIV in a sample of cougars located in the northern Rocky Mountain region of North America, we first used kernel density ratio estimation to map the log relative risk of FIV. The risk surface showed a significant cluster of FIV in northwestern Montana. We also used Bayesian cluster models for genetic data to investigate the spatial structure of the feline immunodeficiency virus with virus genetic sequence data. A result of the models was two spatially distinct FIV lineages that aligned considerably with an interstate highway in Montana. Our results suggest that the use of spatial information and models adds novel insight when investigating an infectious animal disease. The results also suggest that the influence of landscape features likely plays an important role in the spatiotemporal spread of an infectious disease within wildlife populations. PMID:21197421

  2. Zinc status in human immunodeficiency virus infection

    SciTech Connect

    Walter, R.M. Jr.; Oster, M.H.; Lee, T.J.; Flynn, N.; Keen, C.L. )

    1990-01-01

    Plasma zinc and copper concentrations, erythrocyte zinc concentration, copper-zinc superoxide dismutase activity and urinary zinc concentrations were determined for control subjects and individuals with AIDS, ARC, or asymptomatic HIV infection. Significant differences among the population groups were not noted for the above parameters with the exception of plasma copper which was higher in the AIDS group than in other patient groups. These results do not support the idea that zinc deficiency is a common contributory factor of HIV infectivity or clinical expression, nor that HIV infection induces a zinc deficiency.

  3. Inhibition of Mayaro virus infection by bovine lactoferrin.

    PubMed

    Carvalho, Carlos A M; Sousa, Ivanildo P; Silva, Jerson L; Oliveira, Andréa C; Gonçalves, Rafael B; Gomes, Andre M O

    2014-03-01

    Mayaro virus (MAYV) is an arbovirus linked to several sporadic outbreaks of a highly debilitating febrile illness in many regions of South America. MAYV is on the verge of urbanization from the Amazon region and no effective antiviral intervention is available against human infections. Our aim was to investigate whether bovine lactoferrin (bLf), an iron-binding glycoprotein, could hinder MAYV infection. We show that bLf promotes a strong inhibition of virus infection with no cytotoxic effects. Monitoring the effect of bLf on different stages of infection, we observed that virus entry into the cell is the heavily compromised event. Moreover, we found that binding of bLf to the cell is highly dependent on the sulfation of glycosaminoglycans, suggesting that bLf impairs virus entry by blocking these molecules. Our findings highlight the antiviral potential of bLf and reveal an effective strategy against one of the major emerging human pathogens in the neotropics. PMID:24606707

  4. Protective effect of dietary xylitol on influenza A virus infection.

    PubMed

    Yin, Sun Young; Kim, Hyoung Jin; Kim, Hong-Jin

    2014-01-01

    Xylitol has been used as a substitute for sugar to prevent cavity-causing bacteria, and most studies have focused on its benefits in dental care. Meanwhile, the constituents of red ginseng (RG) are known to be effective in ameliorating the symptoms of influenza virus infection when they are administered orally for 14 days. In this study, we investigated the effect of dietary xylitol on influenza A virus infection (H1N1). We designed regimens containing various fractions of RG (RGs: whole extract, water soluble fraction, saponin and polysaccharide) and xylitol, and combination of xylitol with the RG fractions. Mice received the various combinations orally for 5 days prior to lethal influenza A virus infection. Almost all the mice died post challenge when xylitol or RGs were administered separately. Survival was markedly enhanced when xylitol was administered along with RGs, pointing to a synergistic effect. The effect of xylitol plus RG fractions increased with increasing dose of xylitol. Moreover, dietary xylitol along with the RG water soluble fraction significantly reduced lung virus titers after infection. Therefore, we suggest that dietary xylitol is effective in ameliorating influenza-induced symptoms when it is administered with RG fractions, and this protective effect of xylitol should be considered in relation to other diseases. PMID:24392148

  5. Descending Mediastinitis in Epstein-Barr Virus Infection

    PubMed Central

    van Driel, E. M.; Janssen, M. J. F. M.

    2015-01-01

    Our case report describes a previously healthy 34-year-old male who develops a descending mediastinitis as a complication of an Epstein-Barr virus (EBV) infection. The mediastinitis was suspected to have developed by a breakthrough of a peritonsillar abscess through the space between the alar and prevertebral space. PMID:25740774

  6. Influenza A virus and secondary bacterial infection in swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Influenza A virus (IAV) infection alone causes significant disease characterized by respiratory distress and poor growth in pigs. Endemic strains of IAV in North America pigs consist of the subtypes H1N1, H1N2, and H3N2. These circulating strains contain the triple reassortant internal gene (TRIG) c...

  7. Aquagenic urticaria and human immunodeficiency virus infection: treatment with stanozolol.

    PubMed

    Fearfield, L A; Gazzard, B; Bunker, C B

    1997-10-01

    We report the first case of aquagenic urticaria in a patient with human immunodeficiency virus (HIV) infection. This is a rare physical urticaria not previously described in this context. The disorder proved unamenable to conventional treatment with antihistamines, but did respond dramatically to stanozolol, suggesting a novel indication for this anabolic steroid. PMID:9390343

  8. Protective Effect of Dietary Xylitol on Influenza A Virus Infection

    PubMed Central

    Yin, Sun Young; Kim, Hyoung Jin; Kim, Hong-Jin

    2014-01-01

    Xylitol has been used as a substitute for sugar to prevent cavity-causing bacteria, and most studies have focused on its benefits in dental care. Meanwhile, the constituents of red ginseng (RG) are known to be effective in ameliorating the symptoms of influenza virus infection when they are administered orally for 14 days. In this study, we investigated the effect of dietary xylitol on influenza A virus infection (H1N1). We designed regimens containing various fractions of RG (RGs: whole extract, water soluble fraction, saponin and polysaccharide) and xylitol, and combination of xylitol with the RG fractions. Mice received the various combinations orally for 5 days prior to lethal influenza A virus infection. Almost all the mice died post challenge when xylitol or RGs were administered separately. Survival was markedly enhanced when xylitol was administered along with RGs, pointing to a synergistic effect. The effect of xylitol plus RG fractions increased with increasing dose of xylitol. Moreover, dietary xylitol along with the RG water soluble fraction significantly reduced lung virus titers after infection. Therefore, we suggest that dietary xylitol is effective in ameliorating influenza-induced symptoms when it is administered with RG fractions, and this protective effect of xylitol should be considered in relation to other diseases. PMID:24392148

  9. West Nile Virus Infection among the Homeless, Houston, Texas1

    PubMed Central

    Meyer, Tamra E.; Bull, Lara M.; Holmes, Kelly Cain; Pascua, Rhia F.; Travassos da Rosa, Amelia; Gutierrez, Christian R.; Corbin, Tracie; Woodward, Jennifer L.; Taylor, Jeffrey P.; Tesh, Robert B.

    2007-01-01

    Among 397 homeless participants studied, the overall West Nile virus (WNV) seroprevalence was 6.8%. Risk factors for WNV infection included being homeless >1 year, spending >6 hours outside daily, regularly taking mosquito precautions, and current marijuana use. Public health interventions need to be directed toward this high-risk population. PMID:18257995

  10. Physiological effects of Squash vein yellowing virus infection on watermelon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Squash vein yellowing virus (SqVYV) is the cause of viral watermelon vine decline. In this study, watermelon plants of different ages were inoculated with SqVYV to characterize the physiological response to infection and provide new insights into watermelon vine decline. Physiological responses to...

  11. The Variegate Neurological Manifestations of Varicella Zoster Virus Infection

    PubMed Central

    Nagel, Maria A.; Cohrs, Randall J.; Mahalingam, Ravi

    2014-01-01

    Varicella zoster virus (VZV) is an exclusively human neurotropic alphaherpesvirus. Primary infection causes varicella (chickenpox), after which the virus becomes latent in ganglionic neurons along the entire neuraxis. With advancing age or immunosuppression, cell-mediated immunity to VZV declines, and the virus reactivates to cause zoster (shingles), dermatomal distribution, pain, and rash. Zoster is often followed by chronic pain (postherpetic neuralgia), cranial nerve palsies, zoster paresis, vasculopathy, meningoencephalitis, and multiple ocular disorders. This review covers clinical, laboratory, and pathological features of neurological complications of VZV reactivation, including diagnostic testing to verify active VZV infection in the nervous system. Additional perspectives are provided by discussions of VZV latency, animal models to study varicella pathogenesis and immunity, and of the value of vaccination of elderly individuals to boost cell-mediated immunity to VZV and prevent VZV reactivation. PMID:23884722

  12. Current Approaches for Diagnosis of Influenza Virus Infections in Humans.

    PubMed

    Vemula, Sai Vikram; Zhao, Jiangqin; Liu, Jikun; Wang, Xue; Biswas, Santanu; Hewlett, Indira

    2016-04-01

    Despite significant advancement in vaccine and virus research, influenza continues to be a major public health concern. Each year in the United States of America, influenza viruses are responsible for seasonal epidemics resulting in over 200,000 hospitalizations and 30,000-50,000 deaths. Accurate and early diagnosis of influenza viral infections are critical for rapid initiation of antiviral therapy to reduce influenza related morbidity and mortality both during seasonal epidemics and pandemics. Several different approaches are currently available for diagnosis of influenza infections in humans. These include viral isolation in cell culture, immunofluorescence assays, nucleic acid amplification tests, immunochromatography-based rapid diagnostic tests, etc. Newer diagnostic approaches are being developed to overcome the limitations associated with some of the conventional detection methods. This review discusses diagnostic approaches currently available for detection of influenza viruses in humans. PMID:27077877

  13. Current Approaches for Diagnosis of Influenza Virus Infections in Humans

    PubMed Central

    Vemula, Sai Vikram; Zhao, Jiangqin; Liu, Jikun; Wang, Xue; Biswas, Santanu; Hewlett, Indira

    2016-01-01

    Despite significant advancement in vaccine and virus research, influenza continues to be a major public health concern. Each year in the United States of America, influenza viruses are responsible for seasonal epidemics resulting in over 200,000 hospitalizations and 30,000–50,000 deaths. Accurate and early diagnosis of influenza viral infections are critical for rapid initiation of antiviral therapy to reduce influenza related morbidity and mortality both during seasonal epidemics and pandemics. Several different approaches are currently available for diagnosis of influenza infections in humans. These include viral isolation in cell culture, immunofluorescence assays, nucleic acid amplification tests, immunochromatography-based rapid diagnostic tests, etc. Newer diagnostic approaches are being developed to overcome the limitations associated with some of the conventional detection methods. This review discusses diagnostic approaches currently available for detection of influenza viruses in humans. PMID:27077877

  14. [An infected partially thrombosed giant aneurysm of the azygos anterior cerebral artery].

    PubMed

    Mishima, K; Watanabe, T; Sasaki, T; Saito, I; Takakura, K

    1990-05-01

    The authors report a case of partially thrombosed giant aneurysm which was secondarily infected with purulent meningitis. The relationship between the infection of the aneurysm, the rapid growth of the aneurysm and the development of severe cerebral edema was discussed. A 53 year-old man was admitted on September 1, 1986, with a diagnosis of bacterial meningitis. On his admission, his body temperature was 39 degrees C, and he showed mental confusion but no neurological deficits. Laboratory data revealed signs of infection in white blood cell count, CRP, and erythrocyte sedimentation rate. Computerized tomographic (CT) scan and magnetic resonance (MR) imaging showed a massive round mass with perifocal edema measuring 40mm in the maximum diameter in the left paramedian frontal region. T1 weighted MR image also showed the presence of pus accumulation in the left ventricle. Cerebral angiography demonstrated a giant aneurysm at the distal portion of the azygos anterior cerebral artery, and irregular narrowing of both the supraclinoid segment of the carotid artery and its main branches indicating arteritis due to purulent meningitis. The patient was treated with ventricular drainage and administration of antibiotics. Culture of the purulent CSF was negative. The patient's lab data, CSF finding and neurological status improved progressively. However, follow-up CT scan and angiogram a month later showed enlargement of the aneurysm, dilatation of the patent lumen and perifocal edema. On October 8, the patient suddenly became comatose with anisocoria. A CT scan showed massive edema with marked midline shift. Emergency bifrontal craniotomy was carried out, and clipping was completed after removal of the thrombosed portion of the aneurysm, and thromboendarterectomy of the aneurysmal neck.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2385324

  15. Examining Human T-Lymphotropic Virus Type 1 Infection and Replication by Cell-Free Infection with Recombinant Virus Vectors

    PubMed Central

    Derse, David; Hill, Shawn A.; Lloyd, Patricia A.; Chung, Hye-kyung; Morse, Barry A.

    2001-01-01

    A sensitive and quantitative cell-free infection assay, utilizing recombinant human T-cell leukemia virus type 1 (HTLV-1)-based vectors, was developed in order to analyze early events in the virus replication cycle. Previous difficulties with the low infectivity and restricted expression of the virus have prevented a clear understanding of these events. Virus stocks were generated by transfecting cells with three plasmids: (i) a packaging plasmid encoding HTLV-1 structural and regulatory proteins, (ii) an HTLV-1 transfer vector containing either firefly luciferase or enhanced yellow fluorescent protein genes, and (iii) an envelope expression plasmid. Single-round infections were initiated by exposing target cells to filtered supernatants and quantified by assaying for luciferase activity in cell extracts or by enumerating transduced cells by flow cytometry. Transduction was dependent on reverse transcription and integration of the recombinant virus genome, as shown by the effects of the reverse transcriptase inhibitor 3′-azido-3′-deoxythymidine (AZT) and by mutation of the integrase gene in the packaging vector, respectively. The 50% inhibitory concentration of AZT was determined to be 30 nM in this HTLV-1 replication system. The stability of HTLV-1 particles, pseudotyped with either vesicular stomatitis virus G protein or HTLV-1 envelope, was typical of retroviruses, exhibiting a half-life of approximately 3.5 h at 37°C. The specific infectivity of recombinant HTLV-1 virions was at least 3 orders of magnitude lower than that of analogous HIV-1 particles, though both were pseudotyped with the same envelope. Thus, the low infectivity of HTLV-1 is determined in large part by properties of the core particle and by the efficiency of postentry processes. PMID:11507191

  16. CT findings in viral lower respiratory tract infections caused by parainfluenza virus, influenza virus and respiratory syncytial virus

    PubMed Central

    Kim, Min-Chul; Kim, Mi Young; Lee, Hyun Joo; Lee, Sang-Oh; Choi, Sang-Ho; Kim, Yang Soo; Woo, Jun Hee; Kim, Sung-Han

    2016-01-01

    Abstract Viral lower respiratory tract infections (LRTIs) can present with a variety of computed tomography (CT) findings. However, identifying the contribution of a particular virus to CT findings is challenging due to concomitant infections and the limited data on the CT findings in viral LRTIs. We therefore investigate the CT findings in different pure viral LRTIs. All patients who underwent bronchoalveolar lavage (BAL) and were diagnosed with LRTIs caused by parainfluenza virus (PIV), influenza virus, or respiratory syncytial virus (RSV) between 1998 and 2014 were enrolled in a tertiary hospital in Seoul, South Korea. A pure viral LRTI was defined as a positive viral culture from BAL without any positive evidence from respiratory or blood cultures, or from polymerase chain reaction (PCR), or from serologic tests for bacteria, fungi, mycobacteria, or other viruses. CT images of 40 patients with viral LRTIs were analyzed: 14 with PIV, 14 with influenza virus, and 12 with RSV. Patch consolidation (≥1 cm or more than 1 segmental level) was found only in PIV (29%) (P = 0.03), by which CT findings caused by PIV could resemble those seen in bacterial LRTIs. Ground-glass opacities were seen in all cases of influenza virus and were more frequent than in PIV (71%) and RSV (67%) (P = 0.05). Bronchial wall thickening was more common in influenza virus (71%) and RSV (67%) LRTIs than PIV LRTIs (21%) (P = 0.02). With respect to anatomical distribution, PIV infections generally affected the lower lobes (69%), while influenza virus mostly caused diffuse changes throughout the lungs (57%), and RSV frequently formed localized patterns in the upper and mid lobes (44%). The CT findings in LRTIs of PIV, influenza virus, and RSV can be distinguished by certain characteristics. These differences could be useful for early differentiation of these viral LRTIs, and empirical use of appropriate antiviral agents. PMID:27368011

  17. Influenza A virus infections in marine mammals and terrestrial carnivores.

    PubMed

    Harder, Timm C; Siebert, Ursula; Wohlsein, Peter; Vahlenkamp, Thomas

    2013-01-01

    Influenza A viruses (IAV), members of the Orthomyxoviridae, cover a wide host spectrum comprising a plethora of avian and, in comparison, a few mammalian species. The viral reservoir and gene pool are kept in metapopulations of aquatic wild birds. The mammalian-adapted IAVs originally arose by transspecies transmission from avian sources. In swine, horse and man, species-adapted IAV lineages circulate independently of the avian reservoir and cause predominantly respiratory disease of highly variable severity. Sporadic outbreaks of IAV infections associated with pneumonic clinical signs have repeatedly occurred in marine mammals (harbour seals [Phoca vitulina]) off the New England coast of the U.S.A. due to episodic transmission of avian IAV. However, no indigenous marine mammal IAV lineages are described. In contrast to marine mammals, avian- and equine-derived IAVs have formed stable circulating lineages in terrestrial carnivores: IAVs of subtype H3N2 and H3N8 are found in canine populations in South Korea, China, and the U.S.A. Experimental infections revealed that dogs and cats can be infected with an even wider range of avian IAVs. Cats, in particular, also proved susceptible to native infection with human pandemic H1N1 viruses and, according to serological data, may be vulnerable to infection with further human-adapted IAVs. Ferrets are susceptible to a variety of avian and mammalian IAVs and are an established animal model of human IAV infection. Thus, a potential role of pet cats, dogs and ferrets as mediators of avian-derived viruses to the human population does exist. A closer observation for influenza virus infections and transmissions at this animal-human interface is indicated. PMID:24511825

  18. Giant DNA Virus Mimivirus Encodes Pathway for Biosynthesis of Unusual Sugar 4-Amino-4,6-dideoxy-d-glucose (Viosamine)*

    PubMed Central

    Piacente, Francesco; Marin, Margherita; Molinaro, Antonio; De Castro, Cristina; Seltzer, Virginie; Salis, Annalisa; Damonte, Gianluca; Bernardi, Cinzia; Claverie, Jean-Michel; Abergel, Chantal; Tonetti, Michela

    2012-01-01

    Mimivirus is one the largest DNA virus identified so far, infecting several Acanthamoeba species. Analysis of its genome revealed the presence of a nine-gene cluster containing genes potentially involved in glycan formation. All of these genes are co-expressed at late stages of infection, suggesting their role in the formation of the long fibers covering the viral surface. Among them, we identified the L136 gene as a pyridoxal phosphate-dependent sugar aminotransferase. This enzyme was shown to catalyze the formation of UDP-4-amino-4,6-dideoxy-d-glucose (UDP-viosamine) from UDP-4-keto-6-deoxy-d-glucose, a key compound involved also in the biosynthesis of l-rhamnose. This finding further supports the hypothesis that Mimivirus encodes a glycosylation system that is completely independent of the amoebal host. Viosamine, together with rhamnose, (N-acetyl)glucosamine, and glucose, was found as a major component of the viral glycans. Most of the sugars were associated with the fibers, confirming a capsular-like nature of the viral surface. Phylogenetic analysis clearly indicated that L136 was not a recent acquisition from bacteria through horizontal gene transfer, but it was acquired very early during evolution. Implications for the origin of the glycosylation machinery in giant DNA virus are also discussed. PMID:22157758

  19. Differential Sensitivity of Bat Cells to Infection by Enveloped RNA Viruses: Coronaviruses, Paramyxoviruses, Filoviruses, and Influenza Viruses

    PubMed Central

    Hoffmann, Markus; Müller, Marcel Alexander; Drexler, Jan Felix; Glende, Jörg; Erdt, Meike; Gützkow, Tim; Losemann, Christoph; Binger, Tabea; Deng, Hongkui; Schwegmann-Weßels, Christel; Esser, Karl-Heinz; Drosten, Christian; Herrler, Georg

    2013-01-01

    Bats (Chiroptera) host major human pathogenic viruses including corona-, paramyxo, rhabdo- and filoviruses. We analyzed six different cell lines from either Yinpterochiroptera (including African flying foxes and a rhinolophid bat) or Yangochiroptera (genera Carollia and Tadarida) for susceptibility to infection by different enveloped RNA viruses. None of the cells were sensitive to infection by transmissible gastroenteritis virus (TGEV), a porcine coronavirus, or to infection mediated by the Spike (S) protein of SARS-coronavirus (SARS-CoV) incorporated into pseudotypes based on vesicular stomatitis virus (VSV). The resistance to infection was overcome if cells were transfected to express the respective cellular receptor, porcine aminopeptidase N for TGEV or angiotensin-converting enzyme 2 for SARS-CoV. VSV pseudotypes containing the S proteins of two bat SARS-related CoV (Bg08 and Rp3) were unable to infect any of the six tested bat cell lines. By contrast, viral pseudotypes containing the surface protein GP of Marburg virus from the family Filoviridae infected all six cell lines though at different efficiency. Notably, all cells were sensitive to infection by two paramyxoviruses (Sendai virus and bovine respiratory syncytial virus) and three influenza viruses from different subtypes. These results indicate that bat cells are more resistant to infection by coronaviruses than to infection by paramyxoviruses, filoviruses and influenza viruses. Furthermore, these results show a receptor-dependent restriction of the infection of bat cells by CoV. The implications for the isolation of coronaviruses from bats are discussed. PMID:24023659

  20. Differential sensitivity of bat cells to infection by enveloped RNA viruses: coronaviruses, paramyxoviruses, filoviruses, and influenza viruses.

    PubMed

    Hoffmann, Markus; Müller, Marcel Alexander; Drexler, Jan Felix; Glende, Jörg; Erdt, Meike; Gützkow, Tim; Losemann, Christoph; Binger, Tabea; Deng, Hongkui; Schwegmann-Weßels, Christel; Esser, Karl-Heinz; Drosten, Christian; Herrler, Georg

    2013-01-01

    Bats (Chiroptera) host major human pathogenic viruses including corona-, paramyxo, rhabdo- and filoviruses. We analyzed six different cell lines from either Yinpterochiroptera (including African flying foxes and a rhinolophid bat) or Yangochiroptera (genera Carollia and Tadarida) for susceptibility to infection by different enveloped RNA viruses. None of the cells were sensitive to infection by transmissible gastroenteritis virus (TGEV), a porcine coronavirus, or to infection mediated by the Spike (S) protein of SARS-coronavirus (SARS-CoV) incorporated into pseudotypes based on vesicular stomatitis virus (VSV). The resistance to infection was overcome if cells were transfected to express the respective cellular receptor, porcine aminopeptidase N for TGEV or angiotensin-converting enzyme 2 for SARS-CoV. VSV pseudotypes containing the S proteins of two bat SARS-related CoV (Bg08 and Rp3) were unable to infect any of the six tested bat cell lines. By contrast, viral pseudotypes containing the surface protein GP of Marburg virus from the family Filoviridae infected all six cell lines though at different efficiency. Notably, all cells were sensitive to infection by two paramyxoviruses (Sendai virus and bovine respiratory syncytial virus) and three influenza viruses from different subtypes. These results indicate that bat cells are more resistant to infection by coronaviruses than to infection by paramyxoviruses, filoviruses and influenza viruses. Furthermore, these results show a receptor-dependent restriction of the infection of bat cells by CoV. The implications for the isolation of coronaviruses from bats are discussed. PMID:24023659

  1. Infection of human thymocytes by Epstein-Barr virus.

    PubMed

    Watry, D; Hedrick, J A; Siervo, S; Rhodes, G; Lamberti, J J; Lambris, J D; Tsoukas, C D

    1991-04-01

    The Epstein-Barr Virus (EBV) causes infectious mononucleosis, and has been strongly associated with certain human cancers. The virus is thought to exclusively bind to B lymphocytes and epithelial cells via receptors (CR2/CD21) that also interact with fragments of the third component of complement (C3). Recent evidence, however, has challenged this belief. We have used two-color immunofluorescence analysis using biotin-conjugated EBV and streptavidin-phycoerythrin along with fluorescein-conjugated anti-T cell antibodies and demonstrated that CD1-positive, CD3-dull (immature) human thymocytes express functional EBV receptors. In four replicate experiments, the binding of EBV to thymocytes ranged between 8 and 18%. This interaction is specific as evidenced by inhibition with nonconjugated virus, anti-CR2 antibodies, aggregated C3, and an antibody to the gp350 viral glycoprotein that the virus uses to bind to CR2. EBV can infect the thymocytes as evaluated by the presence of episomal EBV-DNA in thymocytes that had been incubated with the virus as short as 12 days or as long as 6 weeks. Episomal DNA analysis was performed by Southern blotting with a EBV-DNA probe that hybridizes to the first internal reiteration of the viral DNA. The presence of the EBV genome is also supported by the detection of EBV nuclear antigen 1 in infected thymocytes, assessed by Western blotting with EBV-immune sera. The EBV infection is specific as determined by blocking experiments using anti-CR2 and anti-gp350 antibodies. Finally, virus infection of thymocytes can act synergistically along with interleukin 2 and induce a lymphokine-dependent cellular proliferation. In view of previously reported cases of EBV-positive human T cell lymphomas, the possibility is raised that EBV may be involved in cancers of T lymphocytes that have not been previously appreciated. PMID:1706754

  2. Equine Influenza A(H3N8) Virus Infection in Cats

    PubMed Central

    Su, Shuo; Wang, Lifang; Fu, Xinliang; He, Shuyi; Hong, Malin; Zhou, Pei; Gray, Gregory

    2014-01-01

    Interspecies transmission of equine influenza A(H3N8) virus has resulted in establishment of a canine influenza virus. To determine if something similar could happen with cats, we experimentally infected 14 cats with the equine influenza A(H3N8) virus. All showed clinical signs, shed virus, and transmitted the virus to a contact cohort. PMID:25417790

  3. Common occurrence of concurrent infections by multiple dengue virus serotypes.

    PubMed

    Loroño-Pino, M A; Cropp, C B; Farfán, J A; Vorndam, A V; Rodríguez-Angulo, E M; Rosado-Paredes, E P; Flores-Flores, L F; Beaty, B J; Gubler, D J

    1999-11-01

    The co-circulation of all 4 dengue virus serotypes in the same community, common since the 1950s in Southeast Asia, has now become a frequent occurrence in many Caribbean Islands, Mexico, and Central and South America in the past 20 years. As a consequence, the frequency of concurrent infections would be expected to increase in these areas. To assess this, using state of the art technology, we screened viremic serum samples and mosquitoes inoculated with serum samples collected during epidemics involving multiple dengue virus serotypes in Indonesia, Mexico, and Puerto Rico for virus isolation. Of 292 samples tested, 16 (5.5%) were found to contain 2 or more dengue viruses by an indirect immunofluorescence test and/or the reverse transcriptase-polymerase chain reaction. PMID:10586902

  4. Pathophysiology of Ebola Virus Infection: Current Challenges and Future Hopes.

    PubMed

    Rivera, Andrea; Messaoudi, Ilhem

    2015-05-01

    The filoviruses, Ebola virus (EBOV) and Marburg virus (MARV), are among the deadliest viruses that cause disease in humans, with reported case fatality rates of up to 90% in some outbreaks. The high virulence of EBOV and MARV is largely attributed to the ability of these viruses to interfere with the host immune response. Currently, there are no approved vaccines or postexposure therapeutics, and treatment options for patients infected with EBOV are limited to supportive care. In this review, we discuss mechanisms of EBOV pathogenesis and its ability to subvert host immunity as well as several vaccines and therapeutics with respect to their evaluation in small animal models, nonhuman primates, and human clinical trials. PMID:27622648

  5. A conservation law for virus infection kinetics in vitro.

    PubMed

    Kakizoe, Yusuke; Morita, Satoru; Nakaoka, Shinji; Takeuchi, Yasuhiro; Sato, Kei; Miura, Tomoyuki; Beauchemin, Catherine A A; Iwami, Shingo

    2015-07-01

    Conservation laws are among the most important properties of a physical system, but are not commonplace in biology. We derived a conservation law from the basic model for viral infections which consists in a small set of ordinary differential equations. We challenged the conservation law experimentally for the case of a virus infection in a cell culture. We found that the derived, conserved quantity remained almost constant throughout the infection period, implying that the derived conservation law holds in this biological system. We also suggest a potential use for the conservation law in evaluating the accuracy of experimental measurements. PMID:25882746

  6. Human Immunodeficiency Virus Infection and Pregnancy

    PubMed Central

    1994-01-01

    The human immunodeficiency virus (HIV) epidemic is clearly one of the most serious health-care crises in the professional lives of contemporary physicians. It cannot be regarded as a curiosity to be dealt with by inner-city infectious-disease experts, but rather must be considered a problem for all health-care providers and a problem in which the obstetrician-gynecologist has a special role to play. PMID:18475370

  7. Lethal experimental infections of rhesus monkeys by aerosolized Ebola virus.

    PubMed Central

    Johnson, E.; Jaax, N.; White, J.; Jahrling, P.

    1995-01-01

    The potential of aerogenic infection by Ebola virus was established by using a head-only exposure aerosol system. Virus-containing droplets of 0.8-1.2 microns were generated and administered into the respiratory tract of rhesus monkeys via inhalation. Inhalation of viral doses as low as 400 plaque-forming units of virus caused a rapidly fatal disease in 4-5 days. The illness was clinically identical to that reported for parenteral virus inoculation, except for the occurrence of subcutaneous and venipuncture site bleeding and serosanguineous nasal discharge. Immunocytochemistry revealed cell-associated Ebola virus antigens present in airway epithelium, alveolar pneumocytes, and macrophages in the lung and pulmonary lymph nodes; extracellular antigen was present on mucosal surfaces of the nose, oropharynx and airways. Aggregates of characteristic filamentous virus were present within type I pneumocytes, macrophages, and air spaces of the lung by electron microscopy. Demonstration of fatal aerosol transmission of this virus in monkeys reinforces the importance of taking appropriate precautions to prevent its potential aerosol transmission to humans. Images Figure 3 Figure 4 Figure 5 PMID:7547435

  8. In vivo imaging of cidofovir treatment of cowpox virus infection.

    PubMed

    Goff, Arthur; Twenhafel, Nancy; Garrison, Aura; Mucker, Eric; Lawler, James; Paragas, Jason

    2007-09-01

    Variola virus and other members of the genus Orthopoxviruses constitute a prominent bioterrorism and public health threat. Treatment with the anti-viral drug cidofovir inhibits replication of orthopoxviruses in vitro and in vivo. In this study, we visualized the effect of cidofovir on viral kinetics in orthopoxvirus infected mice by using whole-body fluorescence imaging (FI). We engineered a cowpox virus (CPV) expressing the enhanced green fluorescent protein (GFP). Single-step growth curves and calculated 50% lethal doses (LD(50)) of wild-type CPX (Wt-CPV) and GFP-expressing CPX (GFP-CPV) were comparable. Whole-body FI first detected GFP fluorescence in the mesenteric tissue of untreated animals on post-infection day (PID) 1. On PID 3 GFP signal was detected throughout the mesentery, in all abdominal organs by PID 5 and in most major organs, except for the heart and brain by PID 6. Infected animals treated with 25mg/kg of cidofovir also began showing signs of viral replication on PID 1, however, the fluorescent signal was limited only to discrete foci throughout the course of the infection. This work describes the first use of an established Orthopox model of infection to evaluate drug efficacy and track virus progression on a macroscopic level. PMID:17524511

  9. Virus-associated papillomatous skin lesions in a giant guitarfish Rhynchobatus djiddensis: a case report.

    PubMed

    Camus, Alvin; Dill, Jennifer; McDermott, Alexa; Camus, Melinda; Fan Ng, Terry Fei

    2016-01-13

    Although elasmobranch species are increasingly displayed in public aquaria, knowledge of disease in wild and captive elasmobranchs, as well as the agents involved, remains limited, and descriptions are often incomplete. This report describes papillomatous skin lesions in a juvenile giant guitarfish Rhynchobatus djiddensis associated with intranuclear viral particles. Skin biopsies were collected from multiple, friable, raised, villonodular skin lesions affecting pigmented and non-pigmented skin of the caudal fin and ventrum, respectively. Microscopic examination revealed papillary proliferation of the epidermis, with widespread marked karyomegaly of squamous epithelial cells. In approximately 75% of nuclei, chromatin was marginated by one to multiple, large, amphophilic inclusions. Large numbers of unencapsulated, 75 nm, icosahedral viral particles were observed to form large arrays in affected nuclei using transmission electron microscopy. Based on intranuclear location, particle size and morphology, a consensus nested-PCR for adenovirus polymerase was attempted. However, no adenoviral gene sequence was amplified. The nature of the involved virus remains unknown and an ongoing area of investigation. Lesions regressed completely over a 6 mo period, during which time the animal showed no signs of systemic illness, and there has been no recrudescence for 6 mo following resolution. Two cohorts of similar age and in close contact with the case animal were unaffected. PMID:26758659

  10. Cutaneous Co-infected Cytomegalovirus and Herpes Simplex Virus Perigenital Ulcers in Human Immunodeficiency Virus Patients.

    PubMed

    Schoenfeld, Jason; Cannon, Sarah; Cam, Kristin; Keller, Matthew

    2013-10-01

    There is uncertainty regarding the pathogenic nature of cytomegalovirus in cutaneous lesions co-infected with herpes simplex virus. It is widely believed that herpes simplex virus is the main pathogenic factor in such lesions and that cytomegalovirus plays little if any role. There are, however, isolated case reports that describe cytomegalovirus as an important driving pathogen in such lesions. The authors present two human immunodeficiency virus patients who have cytomegalovirus and herpes simplex virus co-infected perigenital ulcers, one of whom improved on valacyclovir, while the other, who was already on valacyclovir for chronic herpes simplex virus suppression, showed no improvement with a single dose of cidofovir. He only showed rapid improvement when treated with valganciclovir. The latter patient underscores the viewpoint that at least in some cases, cytomegalovirus may be an important driving force behind the formation of such lesions. The authors therefore recommend that clinicians be aware of the possible pathogenic role of cytomegalovirus in these ulcers, and, in nonhealing ulcers, use anti-cytomegalovirus agents to prevent the onset of systemic disease. These results warrant further study of the pathogenesis of cytomegalovirus in co-infected herpes simplex virus ulcers. PMID:24155993

  11. Determination of Baylisascaris schroederi infection in wild giant pandas by an accurate and sensitive PCR/CE-SSCP method.

    PubMed

    Zhang, Wenping; Yie, Shangmian; Yue, Bisong; Zhou, Jielong; An, Renxiong; Yang, Jiangdong; Chen, Wangli; Wang, Chengdong; Zhang, Liang; Shen, Fujun; Yang, Guangyou; Hou, Rong; Zhang, Zhihe

    2012-01-01

    It has been recognized that other than habitat loss, degradation and fragmentation, the infection of the roundworm Baylisascaris schroederi (B. schroederi) is one of the major causes of death in wild giant pandas. However, the prevalence and intensity of the parasite infection has been inconsistently reported through a method that uses sedimentation-floatation followed by a microscope examination. This method fails to accurately determine infection because there are many bamboo residues and/or few B. schroederi eggs in the examined fecal samples. In the present study, we adopted a method that uses PCR and capillary electrophoresis combined with a single-strand conformation polymorphism analysis (PCR/CE-SSCP) to detect B. schroederi infection in wild giant pandas at a nature reserve, and compared it to the traditional microscope approach. The PCR specifically amplified a single band of 279-bp from both fecal samples and positive controls, which was confirmed by sequence analysis to correspond to the mitochondrial COII gene of B. schroederi. Moreover, it was demonstrated that the amount of genomic DNA was linearly correlated with the peak area of the CE-SSCP analysis. Thus, our adopted method can reliably detect the infectious prevalence and intensity of B. schroederi in wild giant pandas. The prevalence of B. schroederi was found to be 54% in the 91 fecal samples examined, and 48% in the fecal samples of 31 identified individual giant pandas. Infectious intensities of the 91 fecal samples were detected to range from 2.8 to 959.2 units/gram, and from 4.8 to 959.2 units/gram in the fecal samples of the 31 identified giant pandas. For comparison, by using the traditional microscope method, the prevalence of B. schroederi was found to be only 33% in the 91 fecal samples, 32% in the fecal samples of the 31 identified giant pandas, and no reliable infectious intensity was observed. PMID:22911871

  12. Role of macrophages and monocytes in hepatitis C virus infections

    PubMed Central

    Revie, Dennis; Salahuddin, Syed Zaki

    2014-01-01

    A number of studies conducted over many years have shown that hepatitis C virus (HCV) can infect a variety of cell types. In vivo infection of monocytes, macrophages, and dendritic cells by HCV has been frequently shown by a number of researchers. These studies have demonstrated replication of HCV by detecting the presence of both negative genomic strands and a variety of non-structural HCV proteins in infected cells. In addition, analyses of genome sequences have also shown that different cell types can harbor different HCV variants. Investigators have also done preliminary studies of which cellular genes are affected by HCV infection, but there have not yet been a sufficient number of these studies to understand the effects of infection on these cells. Analyses of in vitro HCV replication have shown that monocytes, macrophages and dendritic cells can be infected by HCV from patient sera or plasma. These studies suggest that entry and cellular locations may vary between different cell types. Some studies suggest that macrophages may preferentially allow HCV genotype 1 to replicate, but macrophages do not appear to select particular hypervariable regions. Overall, these studies agree with a model where monocytes and macrophages act as an amplification system, in which these cells are infected and show few cytopathic effects, but continuously produce HCV. This allows them to produce virus over an extended time and allows its spread to other cell types. PMID:24659871

  13. Immune responses of ducks infected with duck Tembusu virus

    PubMed Central

    Li, Ning; Wang, Yao; Li, Rong; Liu, Jiyuan; Zhang, Jinzhou; Cai, Yumei; Liu, Sidang; Chai, Tongjie; Wei, Liangmeng

    2015-01-01

    Duck Tembusu virus (DTMUV) can cause serious disease in ducks, characterized by reduced egg production. Although the virus has been isolated and detection methods developed, the host immune responses to DTMUV infection are unclear. Therefore, we systematically examined the expression of immune-related genes and the viral distribution in DTMUV-infected ducks, using quantitative real-time PCR. Our results show that DTMUV replicates quickly in many tissues early in infection, with the highest viral titers in the spleen 1 day after infection. Rig-1, Mda5, and Tlr3 are involved in the host immune response to DTMUV, and the expression of proinflammatory cytokines (Il-1β, –2, –6, Cxcl8) and antiviral proteins (Mx, Oas, etc.) are also upregulated early in infection. The expression of Il-6 increased most significantly in the tissues tested. The upregulation of Mhc-I was observed in the brain and spleen, but the expression of Mhc-II was upregulated in the brain and downregulated in the spleen. The expression of the interferons was also upregulated to different degrees in the spleen but that of the brain was various. Our study suggests that DTMUV replicates rapidly in various tissues and that the host immune responses are activated early in infection. However, the overexpression of cytokines may damage the host. These results extend our understanding of the immune responses of ducks to DTMUV infection, and provide insight into the pathogenesis of DTMUV attributable to host factors. PMID:26005441

  14. An improved syncytia infectivity assay for the bovine leukemia virus.

    PubMed

    Diglio, C A; Piper, C E; Ferrer, J F

    1978-06-01

    Several factors that influence the sensitivity of the syncytia infectivity assay for the bovine leukemia virus (BLV) and BLV-infected lymphocytes have been examined. The use of early-passage indicator bovine embryonic spleen (BESP) cells and their pretreatment with diethylamino-ethyl-dextran (DEAE-D) was essential for optimal sensitivity. Polybrene was less effective than DEAE-D. The combination of DEAE-D and polybrene was more effective than DEAE-D alone when BLV-infected leukocytes were used as the inoculum, but not when the inoculum was a cell-free BLV preparation. Using BESP cell passages 4 to 11 as indicators, reproducible titers were obtained when aliquots of the same virus stock were assayed at different times after freezer storage. When assaying peripheral blood lymphocytes from infected cattle, optimal syncytia responses were observed consistently by inoculating 5 X 10(6) viable lymphocytes per 60-mm Falcon dish. Centrifugation of peripheral blood leukocytes from BLV-infected cattle in discontinuous bovine serum albumin gradients can be used to separate a subpopulation of infected lymphocytes. Use of this subpopulation as the inoculum, rather than unseparated buffy-coat leukocytes, greatly increases the sensitivity of the syncytia infectivity assay. PMID:210107

  15. Total knee arthroplasty in human immunodeficiency virus-infected hemophiliacs.

    PubMed

    Unger, A S; Kessler, C M; Lewis, R J

    1995-08-01

    Twenty-six knee arthroplasties were performed in 15 patients with hemophilia A and human immunodeficiency virus infection from 1984 to 1991. Patient age range was 27 to 48 years. After an average follow-up period of 6.4 years (range, 1-9 years) all patients were alive and none of the implants had become infected. T4 lymphocyte counts showed some deterioration, which was not clinically significant. All of the patients were improved following surgery. Nineteen implants were rated excellent, four good, and three fair. Infection with human immunodeficiency virus did not adversely affect the clinical outcome of knee arthroplasty at follow-up periods up to 9 years. PMID:8523002

  16. Hepatitis E virus infections in humans and animals.

    PubMed

    Song, Young-Jo; Park, Woo-Jung; Park, Byung-Joo; Lee, Joong-Bok; Park, Seung-Yong; Song, Chang-Seon; Lee, Nak-Hyung; Seo, Kun-Ho; Kang, Young-Sun; Choi, In-Soo

    2014-01-01

    Hepatitis E has traditionally been considered an endemic disease of developing countries. It generally spreads through contaminated water. However, seroprevalence studies have shown that hepatitis E virus (HEV) infections are not uncommon in industrialized countries. In addition, the number of autochthonous hepatitis E cases in these countries is increasing. Most HEV infections in developed countries can be traced to the ingestion of contaminated raw or undercooked pork meat or sausages. Several animal species, including pigs, are known reservoirs of HEV that transmit the virus to humans. HEVs are now recognized as an emerging zoonotic agent. In this review, we describe the general characteristics of HEVs isolated from humans and animals, the risk factors for human HEV infection, and the current status of human vaccine development. PMID:24427760

  17. Hepatitis E virus infections in humans and animals

    PubMed Central

    Song, Young-Jo; Park, Woo-Jung; Park, Byung-Joo; Lee, Joong-Bok; Park, Seung-Yong; Song, Chang-Seon; Lee, Nak-Hyung; Seo, Kun-Ho; Kang, Young-Sun

    2014-01-01

    Hepatitis E has traditionally been considered an endemic disease of developing countries. It generally spreads through contaminated water. However, seroprevalence studies have shown that hepatitis E virus (HEV) infections are not uncommon in industrialized countries. In addition, the number of autochthonous hepatitis E cases in these countries is increasing. Most HEV infections in developed countries can be traced to the ingestion of contaminated raw or undercooked pork meat or sausages. Several animal species, including pigs, are known reservoirs of HEV that transmit the virus to humans. HEVs are now recognized as an emerging zoonotic agent. In this review, we describe the general characteristics of HEVs isolated from humans and animals, the risk factors for human HEV infection, and the current status of human vaccine development. PMID:24427760

  18. Hepatitis B virus infection and primary hepatocellular carcinoma.

    PubMed Central

    Feitelson, M

    1992-01-01

    For many years, epidemiological studies have demonstrated a strong link between chronic hepatitis B virus (HBV) infection and the development of primary hepatocellular carcinoma (PHC). Other hepatocarcinogens such as hepatitis C virus and aflatoxin also contribute to hepatocarcinogenesis either in conjunction with HBV infection or alone. Cellular and molecular biological studies are providing explanations for the HBV-PHC relationship, and models are now being formulated to further test the relative importance of various factors such as viral DNA integration, activation of oncogenes, genetic instability, loss of tumor suppressor genes, and trans-activating properties of HBV to the pathogenesis of PHC. Further research will probably define more than a single mechanism whereby chronic HBV infection results in PHC. PMID:1323384

  19. Herpes simplex Virus Esophagitis in an Immunocompetent Patient with Ebstein-Barr Virus Infection.

    PubMed

    Tzouvala, M; Gaglia, A; Papantoniou, N; Triantafyllou, K; Karamanolis, G

    2008-09-01

    Epstein-Barr virus infectious mononucleosis can cause transient immune deficiency which may predispose to reactivation of latent herpes simplex virus (HSV) infection in the immunocompetent host. We report the case of a 15-year-old male who presented with severe odynophagia and herpes labialis during the course of Epstein-Barr virus infectious mononucleosis that had been diagnosed ten days before. Esophagoscopy revealed extensive ulcerations with distinct borders and whitish exudates at the mid and distal esophagus. Polymerase chain reaction detected HSV-1 DNA in the biopsy specimens. The patient was treated with intravenous acyclovir. The symptoms resolved rapidly within 3 days, in accordance with improved endoscopic findings. PMID:21897798

  20. Cutaneous and diphtheritic avian poxvirus infection in a nestling Southern Giant Petrel (Macronectes giganteus) from Antarctica

    USGS Publications Warehouse

    Shearn-Bochsler, Valerie; Green, David Earl; Converse, K.A.; Docherty, D.E.; Thiel, T.; Geisz, H.N.; Fraser, William R.; Patterson-Fraser, Donna L.

    2008-01-01

    The Southern giant petrel (Macronectes giganteus) is declining over much of its range and currently is listed as vulnerable to extinction by the International Union for the Conservation of Nature (IUCN). Island-specific breeding colonies near Palmer Station, Antarctica, have been monitored for over 30 years, and because this population continues to increase, it is critically important to conservation. In austral summer 2004, six diseased giant petrel chicks were observed in four of these colonies. Diseased chicks were 6a??9 weeks old and had multiple proliferative nodules on their bills and skin. One severely affected chick was found dead on the nest and was salvaged for necropsy. Histopathological examination of nodules from the dead chick revealed epithelial cell hyperplasia and hypertrophy with numerous eosinophilic intracytoplasmic inclusions (B??llinger bodies). A poxvirus was isolated from multiple nodules. Poxviral infection has not been reported in this species, and the reason for its emergence and its potential impact on the population are not yet known.

  1. Analysis of Subcellular Prefoldin 1 Redistribution During Rabies Virus Infection

    PubMed Central

    Zhang, Jinyang; Han, Qinqin; Song, Yuzhu; Chen, Qiang; Xia, Xueshan

    2015-01-01

    Background: Rabies virus (RABV) is one of the old deadly zoonotic viruses. It attacks the central nervous system and causes acute encephalitis in humans and animals. Host factors are known to be essential for virus infection and replication in cells. The identification of the key host factors required for RABV infection may provide important information on RABV replication and may provide new potential targets for RABV drug discovery. Objectives: This study aimed to investigate the change in the subcellular distribution and expression of the host protein Prefoldin subunit 1 (PFDN1) in RABV-infected cells and the viral expression of plasmids in the transfected cells. Materials and Methods: Mouse Neuro-2a (N2a) cells were infected by RABV or transfected with the plasmids of the nucleoprotein (N) and/or phosphoprotein (P) gene of RABV. The subcellular distribution of PFDN1 was analyzed by confocal microscopy, and the transcription levels of PFDN1 in the N and/or P gene of the RABV-transfected or RABV-infected N2a cells were assessed via real-time quantitative polymerase chain reaction. Results: Confocal microscopy showed that PFDN1 was colocalized with the N protein of RABV in the infected N2a cells and was mainly recruited to the characteristic Negri-Body-Like (NBL) structures in the cytoplasm, as well as the cotransfection of the N and P genes of RABV. The transcription of PFDN1 in the RABV-infected N2a cells was upregulated, whereas the transfection of the N and/or P genes did not result in the upregulation of PFDN1. Conclusions: The results of this work demonstrated that the subcellular distribution of PFDN1 was altered in the RABV-infected N2a cells and colocalized with the N protein of RABV in the NBL structures. PMID:26421138

  2. Two small virus-specific polypeptides are produced during infection with Sindbis virus.

    PubMed Central

    Welch, W J; Sefton, B M

    1979-01-01

    We have identified and characterized two small virus-specific polypeptides which are produced during infection of cells with Sindbis virus, but which are not incorporated into the mature virion. The larger of these is a glycoprotein with an approximate molecular weight of 9,800 and is found predominantly in the medium of infected cells. Three independent lines of evidence demonstrate conclusively that this 9,800-dalton glycoprotein is produced during the proteolytic conversion of the precursor polypeptide, PE2, to the virion glycoprotein E2. This small glycoprotein is therefore analogous to the virion glycoprotein E3 of the very closely related alphavirus, Semliki Forest virus. The 9,800-dalton glycoprotein of Sindbis virus, unlike the E3 glycoprotein of Semliki Forest virus, is not, however, present in the viral particle. The other virus-specific polypeptide is 4,200 daltons in size, does not appear to be a glycoprotein, and is neither incorporated into the mature virus nor released into the culture medium. The gene for this small polypeptide is present in the viral 26S mRNA (the mRNA which encodes all the viral structural polypeptides) and appears to be located in the portion of the mRNA which encodes the two viral glycoproteins. The possibility that this 4,200-dalton polypeptide functions as a signal peptide during the synthesis of the viral membrane glycoproteins is discussed. Images PMID:448798

  3. Human trophoblasts confer resistance to viruses implicated in perinatal infection

    PubMed Central

    BAYER, Avraham; DELORME-AXFORD, Elizabeth; SLEIGHER, Christie; FREY, Teryl K.; TROBAUGH, Derek W.; KLIMSTRA, William B.; EMERT-SEDLAK, Lori A.; SMITHGALL, Thomas E.; KINCHINGTON, Paul R.; VADIA, Stephen; SEVEAU, Stephanie; Boyle, Jon P.

    2014-01-01

    Objective(s) Primary human trophoblasts were previously shown to be resistant to viral infection, and able to confer this resistance to non-trophoblast cells. Can trophoblasts protect non-trophoblastic cells from infection by viruses or other intracellular pathogens that are implicated in perinatal infection? Study Design Isolated primary term human trophoblasts were cultured for 72 h. Diverse non-placental human cell lines (U2OS, HFF, TZM-bl, MeWo, and Caco-2) were pre-exposed to either trophoblast conditioned, non-conditioned medium, or miR-517-3p for 24 h. Cells were infected with several viral and non-viral pathogens known to be associated with perinatal infections. Cellular infection was defined and quantified by plaque assays, luciferase assays, microscopy, and/or colonization assays. Differences in infection were assessed by Student's t-test or ANOVA with Bonferroni's correction. Results Infection by rubella and other togaviruses, HIV-1, and varicella zoster, was attenuated in cells pre-exposed to trophoblast conditioned medium (p <0.05), and a partial effect by the Ch.19 microRNA miR-517-3p on specific pathogens. The conditioned medium had no effect on infection by Toxoplasma gondii or Listeria monocytogenes. Conclusion Our findings indicate that medium conditioned by primary human trophoblasts attenuate viral infection in non-trophoblastic cells. Our data point to a trophoblast-specific antiviral effect that may be exploited therapeutically. PMID:25108145

  4. Individual Correlates of Infectivity of Influenza A Virus Infections in Households

    PubMed Central

    Tsang, Tim K.; Fang, Vicky J.; Chan, Kwok-Hung; Ip, Dennis K. M.; Leung, Gabriel M.; Peiris, J. S. Malik; Cauchemez, Simon

    2016-01-01

    Background Identifying individual correlates of infectivity of influenza virus is important for disease control and prevention. Viral shedding is used as a proxy measure of infectivity in many studies. However, the evidence for this is limited. Methods In a detailed study of influenza virus transmission within households in 2008–12, we recruited index cases with confirmed influenza infection from outpatient clinics, and followed up their household contacts for 7–10 days to identify secondary infections. We used individual-based hazard models to characterize the relationship between individual viral shedding and individual infectivity. Results We analyzed 386 households with 1147 household contacts. Index cases were separated into 3 groups according to their estimated level of viral shedding at symptom onset. We did not find a statistically significant association of virus shedding with transmission. Index cases in medium and higher viral shedding groups were estimated to have 21% (95% CI: -29%, 113%) and 44% (CI: -16%, 167%) higher infectivity, compared with those in the lower viral shedding group. Conclusions Individual viral load measured by RT-PCR in the nose and throat was at most weakly correlated with individual infectivity in households. Other correlates of infectivity should be examined in future studies. PMID:27153194

  5. Bacterial vaginosis and human immunodeficiency virus infection

    PubMed Central

    Spear, Gregory T; St John, Elizabeth; Zariffard, M Reza

    2007-01-01

    Epidemiologic studies indicate that bacterial vaginosis (BV), a common alteration of lower genital tract flora in women, is associated with increased susceptibility to HIV infection. Other recent studies show that HIV is detected more frequently and at higher levels in the lower genital tract of HIV-seropositive women with BV. In vitro studies show that genital tract secretions from women with BV or flora associated with BV induce HIV expression in infected cells. The increased HIV expression appears to be due at least in part to activation through Toll-like receptors (TLR), specifically TLR2. Further research is needed to elucidate how BV contributes to HIV acquisition and transmission. PMID:17953761

  6. Viral metagenomics: are we missing the giants?

    PubMed

    Halary, S; Temmam, S; Raoult, D; Desnues, C

    2016-06-01

    Amoeba-infecting giant viruses are recently discovered viruses that have been isolated from diverse environments all around the world. In parallel to isolation efforts, metagenomics confirmed their worldwide distribution from a broad range of environmental and host-associated samples, including humans, depicting them as a major component of eukaryotic viruses in nature and a possible resident of the human/animal virome whose role is still unclear. Nevertheless, metagenomics data about amoeba-infecting giant viruses still remain scarce, mainly because of methodological limitations. Efforts should be pursued both at the metagenomic sample preparation level and on in silico analyses to better understand their roles in the environment and in human/animal health and disease. PMID:26851442

  7. Health care-associated hepatitis C virus infection

    PubMed Central

    Pozzetto, Bruno; Memmi, Meriam; Garraud, Olivier; Roblin, Xavier; Berthelot, Philippe

    2014-01-01

    Hepatitis C virus (HCV) is a blood-borne pathogen that has a worldwide distribution and infects millions of people. Care-associated HCV infections represented a huge part of hepatitis C burden in the past via contaminated blood and unsafe injections and continue to be a serious problem of public health. The present review proposes a panorama of health care-associated HCV infections via the three mode of contamination that have been identified: (1) infected patient to non-infected patient; (2) infected patient to non-infected health care worker (HCW); and (3) infected HCW to non infected patient. For each condition, the circumstances of contamination are described together with the means to prevent them. As a whole, the more important risk is represented by unsafe practices regarding injections, notably with the improper use of multidose vials used for multiple patients. The questions of occupational exposures and infected HCWs are also discussed. In terms of prevention and surveillance, the main arm for combating care-associated HCV infections is the implementation of standard precautions in all the fields of cares, with training programs and audits to verify their good application. HCWs must be sensitized to the risk of blood-borne pathogens, notably by the use of safety devices for injections and good hygiene practices in the operating theatre and in all the invasive procedures. The providers performing exposed-prone procedures must monitor their HCV serology regularly in order to detect early any primary infection and to treat it without delay. With the need to stay vigilant because HCV infection is often a hidden risk, it can be hoped that the number of people infected by HCV via health care will decrease very significantly in the next years. PMID:25516637

  8. Proteasome Inhibition Suppresses Dengue Virus Egress in Antibody Dependent Infection

    PubMed Central

    Costa, Vivian V.; Tan, Hwee Cheng; Horrevorts, Sophie; Ooi, Eng Eong

    2015-01-01

    The mosquito-borne dengue virus (DENV) is a cause of significant global health burden, with an estimated 390 million infections occurring annually. However, no licensed vaccine or specific antiviral treatment for dengue is available. DENV interacts with host cell factors to complete its life cycle although this virus-host interplay remains to be fully elucidated. Many studies have identified the ubiquitin proteasome pathway (UPP) to be important for successful DENV production, but how the UPP contributes to DENV life cycle as host factors remains ill defined. We show here that proteasome inhibition decouples infectious virus production from viral RNA replication in antibody-dependent infection of THP-1 cells. Molecular and imaging analyses in β-lactone treated THP-1 cells suggest that proteasome function does not prevent virus assembly but rather DENV egress. Intriguingly, the licensed proteasome inhibitor, bortezomib, is able to inhibit DENV titers at low nanomolar drug concentrations for different strains of all four serotypes of DENV in primary monocytes. Furthermore, bortezomib treatment of DENV-infected mice inhibited the spread of DENV in the spleen as well as the overall pathological changes. Our findings suggest that preventing DENV egress through proteasome inhibition could be a suitable therapeutic strategy against dengue. PMID:26565697

  9. Proteasome Inhibition Suppresses Dengue Virus Egress in Antibody Dependent Infection.

    PubMed

    Choy, Milly M; Zhang, Summer L; Costa, Vivian V; Tan, Hwee Cheng; Horrevorts, Sophie; Ooi, Eng Eong

    2015-11-01

    The mosquito-borne dengue virus (DENV) is a cause of significant global health burden, with an estimated 390 million infections occurring annually. However, no licensed vaccine or specific antiviral treatment for dengue is available. DENV interacts with host cell factors to complete its life cycle although this virus-host interplay remains to be fully elucidated. Many studies have identified the ubiquitin proteasome pathway (UPP) to be important for successful DENV production, but how the UPP contributes to DENV life cycle as host factors remains ill defined. We show here that proteasome inhibition decouples infectious virus production from viral RNA replication in antibody-dependent infection of THP-1 cells. Molecular and imaging analyses in β-lactone treated THP-1 cells suggest that proteasome function does not prevent virus assembly but rather DENV egress. Intriguingly, the licensed proteasome inhibitor, bortezomib, is able to inhibit DENV titers at low nanomolar drug concentrations for different strains of all four serotypes of DENV in primary monocytes. Furthermore, bortezomib treatment of DENV-infected mice inhibited the spread of DENV in the spleen as well as the overall pathological changes. Our findings suggest that preventing DENV egress through proteasome inhibition could be a suitable therapeutic strategy against dengue. PMID:26565697

  10. Virus Infection and Titration of SARS-CoV in Mouse Lung

    PubMed Central

    Fett, Craig; Zhao, Jincun; Perlman, Stanley

    2016-01-01

    Two critical steps when investigating an animal model of a virus infection are consistently successfully infecting animals and accurately determining viral titers in tissue throughout the course of infection. Here we discuss in detail how to infect mice with SARS-CoV and then quantify the titer of virus in the lung.

  11. Modelling Virus and Antibody Dynamics during Dengue Virus Infection Suggests a Role for Antibody in Virus Clearance

    PubMed Central

    Clapham, Hannah E; Dorigatti, Ilaria; Simmons, Cameron P; Ferguson, Neil M

    2016-01-01

    Dengue is an infection of increasing global importance, yet uncertainty remains regarding critical aspects of its virology, immunology and epidemiology. One unanswered question is how infection is controlled and cleared during a dengue infection. Antibody is thought to play a role, but little past work has examined the kinetics of both virus and antibody during natural infections. We present data on multiple virus and antibody titres measurements recorded sequentially during infection from 53 Vietnamese dengue patients. We fit mechanistic mathematical models of the dynamics of viral replication and the host immune response to these data. These models fit the data well. The model with antibody removing virus fits the data best, but with a role suggested for ADCC or other infected cell clearance mechanisms. Our analysis therefore shows that the observed viral and antibody kinetics are consistent with antibody playing a key role in controlling viral replication. This work gives quantitative insight into the relationship between antibody levels and the efficiency of viral clearance. It will inform the future development of mechanistic models of how vaccines and antivirals might modify the course of natural dengue infection. PMID:27213681

  12. Modelling Virus and Antibody Dynamics during Dengue Virus Infection Suggests a Role for Antibody in Virus Clearance.

    PubMed

    Clapham, Hannah E; Quyen, Than Ha; Kien, Duong Thi Hue; Dorigatti, Ilaria; Simmons, Cameron P; Ferguson, Neil M

    2016-05-01

    Dengue is an infection of increasing global importance, yet uncertainty remains regarding critical aspects of its virology, immunology and epidemiology. One unanswered question is how infection is controlled and cleared during a dengue infection. Antibody is thought to play a role, but little past work has examined the kinetics of both virus and antibody during natural infections. We present data on multiple virus and antibody titres measurements recorded sequentially during infection from 53 Vietnamese dengue patients. We fit mechanistic mathematical models of the dynamics of viral replication and the host immune response to these data. These models fit the data well. The model with antibody removing virus fits the data best, but with a role suggested for ADCC or other infected cell clearance mechanisms. Our analysis therefore shows that the observed viral and antibody kinetics are consistent with antibody playing a key role in controlling viral replication. This work gives quantitative insight into the relationship between antibody levels and the efficiency of viral clearance. It will inform the future development of mechanistic models of how vaccines and antivirals might modify the course of natural dengue infection. PMID:27213681

  13. Virus-Like Vesicle-Based Therapeutic Vaccine Vectors for Chronic Hepatitis B Virus Infection

    PubMed Central

    Reynolds, Tracy D.; Buonocore, Linda; Rose, Nina F.; Rose, John K.

    2015-01-01

    ABSTRACT More than 500,000 people die each year from the liver diseases that result from chronic hepatitis B virus (HBV) infection. Therapeutic vaccines, which aim to elicit an immune response capable of controlling the virus, offer a potential new treatment strategy for chronic hepatitis B. Recently, an evolved, high-titer vaccine platform consisting of Semliki Forest virus RNA replicons that express the vesicular stomatitis virus glycoprotein (VSV G) has been described. This platform generates virus-like vesicles (VLVs) that contain VSV G but no other viral structural proteins. We report here that the evolved VLV vector engineered to additionally express the HBV middle surface envelope glycoprotein (MHBs) induces functional CD8 T cell responses in mice. These responses were greater in magnitude and broader in specificity than those obtained with other immunization strategies, including recombinant protein and DNA. Additionally, a single immunization with VLV-MHBs protected mice from HBV hydrodynamic challenge, and this protection correlated with the elicitation of a CD8 T cell recall response. In contrast to MHBs, a VLV expressing HBV core protein (HBcAg) neither induced a CD8 T cell response in mice nor protected against challenge. Finally, combining DNA and VLV-MHBs immunization led to induction of HBV-specific CD8 T cell responses in a transgenic mouse model of chronic HBV infection. The ability of VLV-MHBs to induce a multispecific T cell response capable of controlling HBV replication, and to generate immune responses in a tolerogenic model of chronic infection, indicates that VLV vaccine platforms may offer a unique strategy for HBV therapeutic vaccination. IMPORTANCE HBV infection is associated with significant morbidity and mortality. Furthermore, treatments for chronic infection are suboptimal and rarely result in complete elimination of the virus. Therapeutic vaccines represent a unique approach to HBV treatment and have the potential to induce long

  14. Characterization of Lethal Zika Virus Infection in AG129 Mice

    PubMed Central

    Walker, Emma C.; Larkin, Katrina E.; Camacho, Erwin; Osorio, Jorge E.

    2016-01-01

    Background Mosquito-borne Zika virus (ZIKV) typically causes a mild and self-limiting illness known as Zika fever, which often is accompanied by maculopapular rash, headache, and myalgia. During the current outbreak in South America, ZIKV infection during pregnancy has been hypothesized to cause microcephaly and other diseases. The detection of ZIKV in fetal brain tissue supports this hypothesis. Because human infections with ZIKV historically have remained sporadic and, until recently, have been limited to small-scale epidemics, neither the disease caused by ZIKV nor the molecular determinants of virulence and/or pathogenicity have been well characterized. Here, we describe a small animal model for wild-type ZIKV of the Asian lineage. Methodology/Principal Findings Using mice deficient in interferon α/β and Ɣ receptors (AG129 mice), we report that these animals were highly susceptible to ZIKV infection and disease, succumbing within seven to eight days. Rapid viremic dissemination was observed in visceral organs and brain; but only was associated with severe pathologies in the brain and muscle. Finally, these results were consistent across challenge routes, age of mice, and inoculum doses. These data represent a mouse model for ZIKV that is not dependent on adapting ZIKV to intracerebral passage in mice. Conclusions/Significance Foot pad injection of AG129 mice with ZIKV represents a biologically relevant model for studying ZIKV infection and disease development following wild-type virus inoculation without the requirement for adaptation of the virus or intracerebral delivery of the virus. This newly developed Zika disease model can be exploited to identify determinants of ZIKV virulence and reveal molecular mechanisms that control the virus-host interaction, providing a framework for rational design of acute phase therapeutics and for vaccine efficacy testing. PMID:27093158

  15. Locally acquired hepatitis E virus infection, El Paso, Texas.

    PubMed

    Amon, Joseph J; Drobeniuc, Jan; Bower, William A; Magaña, Jorge C; Escobedo, Miguel A; Williams, Ian T; Bell, Beth P; Armstrong, Gregory L

    2006-06-01

    Hepatitis E virus (HEV) is an enterically transmitted RNA virus that causes both epidemic and sporadic cases of acute hepatitis. Despite sero-surveys showing antibody to HEV in up to 36% of the US population, acute hepatitis E has been reported among individuals with no history of international travel only three times in the United States. We report a case of apparently locally-acquired hepatitis E that occurred in El Paso, Texas that was 98% similar to a previously isolated HEV found in swine in the United States. Like the three previous cases, a thorough investigation found no conclusive sources of infection. Active case surveillance found no additional cases. PMID:16628579

  16. Border Control in Hepatitis C Virus Infection: Inhibiting Viral Entry.

    PubMed

    Schweitzer, Cameron J; Liang, T Jake

    2015-09-11

    A new era has begun in the treatment of hepatitis C virus (HCV) infection with powerful yet expensive therapies. New treatments are emerging that target the entry step of HCV and could potentially block reinfection after liver transplant. These treatments include antibodies, which target the virus or host receptors required by HCV. Additionally, several new and previously approved small-molecule compounds have been described that target unique aspects of HCV entry. Overall, the blocking entry represents an attractive strategy that could yield powerful combination therapies to combat HCV. PMID:27617924

  17. Antiviral therapy for human immunodeficiency virus infections.

    PubMed Central

    De Clercq, E

    1995-01-01

    Depending on the stage of their intervention with the viral replicative cycle, human immunodeficiency virus inhibitors could be divided into the following groups: (i) adsorption inhibitors (i.e., CD4 constructs, polysulfates, polysulfonates, polycarboxylates, and polyoxometalates), (ii) fusion inhibitors (i.e., plant lectins, succinylated or aconitylated albumins, and betulinic acid derivatives), (iii) uncoating inhibitors (i.e., bicyclams), (iv) reverse transcription inhibitors acting either competitively with the substrate binding site (i.e., dideoxynucleoside analogs and acyclic nucleoside phosphonates) or allosterically with a nonsubstrate binding site (i.e., non-nucleoside reverse transcriptase inhibitors), (v) integration inhibitors, (vi) DNA replication inhibitors, (vii) transcription inhibitors (i.e., antisense oligodeoxynucleotides and Tat antagonists), (viii) translation inhibitors (i.e., antisense oligodeoxynucleotides and ribozymes), (ix) maturation inhibitors (i.e., protease inhibitors, myristoylation inhibitors, and glycosylation inhibitors), and finally, (x) budding (assembly/release) inhibitors. Current knowledge, including the therapeutic potential, of these various inhibitors is discussed. In view of their potential clinical the utility, the problem of virus-drug resistance and possible strategies to circumvent this problem are also addressed. PMID:7542558

  18. Interval Between Infections and Viral Hierarchy Are Determinants of Viral Interference Following Influenza Virus Infection in a Ferret Model

    PubMed Central

    Laurie, Karen L.; Guarnaccia, Teagan A.; Carolan, Louise A.; Yan, Ada W. C.; Aban, Malet; Petrie, Stephen; Cao, Pengxing; Heffernan, Jane M.; McVernon, Jodie; Mosse, Jennifer; Kelso, Anne; McCaw, James M.; Barr, Ian G.

    2015-01-01

    Background. Epidemiological studies suggest that, following infection with influenza virus, there is a short period during which a host experiences a lower susceptibility to infection with other influenza viruses. This viral interference appears to be independent of any antigenic similarities between the viruses. We used the ferret model of human influenza to systematically investigate viral interference. Methods. Ferrets were first infected then challenged 1–14 days later with pairs of influenza A(H1N1)pdm09, influenza A(H3N2), and influenza B viruses circulating in 2009 and 2010. Results. Viral interference was observed when the interval between initiation of primary infection and subsequent challenge was <1 week. This effect was virus specific and occurred between antigenically related and unrelated viruses. Coinfections occurred when 1 or 3 days separated infections. Ongoing shedding from the primary virus infection was associated with viral interference after the secondary challenge. Conclusions. The interval between infections and the sequential combination of viruses were important determinants of viral interference. The influenza viruses in this study appear to have an ordered hierarchy according to their ability to block or delay infection, which may contribute to the dominance of different viruses often seen in an influenza season. PMID:25943206

  19. Herpes simplex virus 2 infection impacts stress granule accumulation.

    PubMed

    Finnen, Renée L; Pangka, Kyle R; Banfield, Bruce W

    2012-08-01

    Interference with stress granule (SG) accumulation is gaining increased appreciation as a common strategy used by diverse viruses to facilitate their replication and to cope with translational arrest. Here, we examined the impact of infection by herpes simplex virus 2 (HSV-2) on SG accumulation by monitoring the localization of the SG components T cell internal antigen 1 (TIA-1), Ras-GTPase-activating SH3-domain-binding protein (G3BP), and poly(A)-binding protein (PABP). Our results indicate that SGs do not accumulate in HSV-2-infected cells and that HSV-2 can interfere with arsenite-induced SG accumulation early after infection. Surprisingly, SG accumulation was inhibited despite increased phosphorylation of eukaryotic translation initiation factor 2α (eIF2α), implying that HSV-2 encodes previously unrecognized activities designed to maintain translation initiation downstream of eIF2α. SG accumulation was not inhibited in HSV-2-infected cells treated with pateamine A, an inducer that works independently of eIF2α phosphorylation. The SGs that accumulated following pateamine A treatment of infected cells contained G3BP and PABP but were largely devoid of TIA-1. We also identified novel nuclear structures containing TIA-1 that form late in infection. These structures contain the RNA binding protein 68-kDa Src-associated in mitosis (Sam68) and were noticeably absent in infected cells treated with inhibitors of viral DNA replication, suggesting that they arise as a result of late events in the virus replicative cycle. PMID:22623775

  20. Hepatitis during respiratory syncytial virus infection – a case report

    PubMed Central

    Kirin, Branka Kristić; Topić, Renata Zrinski; Dodig, Slavica

    2013-01-01

    Introduction: Respiratory syncytial virus (RSV) infection is the most common cause of hospitalization in infants and small children. The aim was to present a 13-months old boy diagnosed with acute airway infection, acute otitis media (AOM) and hepatitis during the RSV-infection. Material and methods: Serum catalytic activities of alkaline phosphatase (ALP), aspartate aminotranspherase (AST), alanine aminotranspherase (ALT), gamma glutamyl transpherase (GGT), lactate dehydrogenase (LD), and concentrations of bilirubin were monitored during hospitalization and at control examination. Results: The child had clinical signs and symptoms of respiratory failure, AOM, and laboratory findings of virus infection and liver disease. On admission, catalytic activities of enzymes were markedly increased, especially the activity of ALP (10333 U/L, i.e. 24-fold increase in comparison with the upper reference limit). The highest increased in AST (339 U/L, 4.5-fold), ALT (475 U/L, 10.3-fold) and LD (545 U/L, 1.5-fold) were registered on the 3rd day, and the highest increase in GGT (68 U/L, 3.1-fold) occurred on the 11th day. Seven weeks after discharge AST, ALT, GGT and LD decreased into reference range, and ALP remain mildly increased (478 U/L, 1.1 fold increase). RSV was confirmed in nasal lavage fluid. Conclusion: Laboratory results in patient with RSV infection needs to be interpreted in the light of both, respiratory and extrapulmonary manifestations of the infection, respectively. PMID:23457772

  1. Frontiers in the Treatment of Hepatitis C Virus Infection

    PubMed Central

    Ahn, Joseph

    2014-01-01

    In the United States, chronic hepatitis C virus (HCV) infection is the leading cause of blood-borne, virus-associated death related to advanced liver disease and the leading indication for liver transplantation. Although the diagnostic test for HCV has been available for more than 20 years, the majority of persons with HCV infection still have not received a diagnosis. This has led to a recent change in screening recommendations by the Centers for Disease Control and Prevention. Moreover, new medications were approved in 2011 after nearly a decade of minimal progress in the development of treatments for HCV infection. This was followed by the highly anticipated approval of sofosbuvir and simeprevir in 201 3. In the past 3 years, there has been an explosion of reports on medications from different classes, promising a dramatic expansion to an all-oral regimen for the treatment of HCV genotype 1 infection within the next few years. This article reviews the current screening recommendations and standard of care for treatment of HCV infection and highlights specific agents in the pipeline that should change the landscape of how HCV infection is treated in the near future. PMID:24803873

  2. Hepatitis B virus infection and metabolic syndrome: fact or fiction?

    PubMed

    Wang, Chia-Chi; Tseng, Tai-Chung; Kao, Jia-Horng

    2015-01-01

    Although hepatitis C virus infection is known to be linked with insulin resistance, dyslipidemia, and hepatic steatosis, the relationship between hepatitis B virus (HBV) infection and metabolic factors remains unclear. HBV infection is a health problem worldwide, especially in endemic regions such as Asia and Africa. It induces liver decompensation, cirrhosis, hepatocellualr carcinoma, and premature mortality. The prevalence of metabolic syndrome continues to increase in parallel with the epidemic of obesity, which is closely associated with the development of diabetes, cardiovascular disease, or even cancer. The systemic review shows that chronic HBV infection protects against instead of promotes fatty liver. The mechanism is possibly due to a lower frequency of dyslipidemia profile in patients with chronic HBV infection. The association of HBV with metabolic syndrome, insulin resistance, and the risk of arteriosclerosis is still inconclusive. In addition, obesity, diabetes, and metabolic syndrome may accelerate the progression of liver disease in patients with chronic HBV infection and synergistically induce cirrhosis or even hepatocellualr carcinoma development. PMID:25092429

  3. Activated mouse eosinophils protect against lethal respiratory virus infection

    PubMed Central

    Percopo, Caroline M.; Dyer, Kimberly D.; Ochkur, Sergei I.; Luo, Janice L.; Fischer, Elizabeth R.; Lee, James J.; Lee, Nancy A.; Domachowske, Joseph B.

    2014-01-01

    Eosinophils are recruited to the airways as a prominent feature of the asthmatic inflammatory response where they are broadly perceived as promoting pathophysiology. Respiratory virus infections exacerbate established asthma; however, the role of eosinophils and the nature of their interactions with respiratory viruses remain uncertain. To explore these questions, we established acute infection with the rodent pneumovirus, pneumonia virus of mice (PVM), in 3 distinct mouse models of Th2 cytokine–driven asthmatic inflammation. We found that eosinophils recruited to the airways of otherwise naïve mice in response to Aspergillus fumigatus, but not ovalbumin sensitization and challenge, are activated by and degranulate specifically in response to PVM infection. Furthermore, we demonstrate that activated eosinophils from both Aspergillus antigen and cytokine-driven asthma models are profoundly antiviral and promote survival in response to an otherwise lethal PVM infection. Thus, although activated eosinophils within a Th2-polarized inflammatory response may have pathophysiologic features, they are also efficient and effective mediators of antiviral host defense. PMID:24297871

  4. Juvenile rheumatoid arthritis in children with Ebstein Barr virus infection.

    PubMed

    Aghighi, Y; Gilani Sh, Modarres; Razavi, M; Zamani, A; Daneshjoo, K

    2007-10-15

    Juvenile Rheumatoid Arthritis (JRA) is a disease of unknown etiology. A total of 50 patients with JRA who were hospitalized in the Pediatrics Rheumatology Ward of Imam Khomeini Hospital in Tehran during the years 2001-2002, were assessed serologically (IgM and IgG specific viral capsid antigens) for EBV infection and their response to therapy was studied. Minimum age of the patients was at least 6 months and mean age was 60.96 plus/minus 43.46 months. EBV infection was seen in 44 (88%) patients 24 of whom were girls and 20 boys. Ninety two percent of girls and 83% boys were infected with the virus. Ebstein barr virus (EBV) infection was seen in 33 cases, 6 cases, 4 cases and 1 case in the polyarticular, pauciarticular, systemic and spondylitis group, respectively. Fifty four percent of EBV-positive patients with JRA did not respond to the classic therapy. EBV virus is involved in the pathogenesis of JRA and patients with EBV are in greater risk of developing JRA. PMID:19093474

  5. Pathogenesis of Lassa virus infection in guinea pigs.

    PubMed Central

    Jahrling, P B; Smith, S; Hesse, R A; Rhoderick, J B

    1982-01-01

    A rodent model for human Lassa fever was developed which uses inbred (strain 13) and outbred (Hartley) guinea pigs. Strain 13 guinea pigs were uniformly susceptible to lethal infection by 2 or more PFU of Lassa virus strain Josiah. In contrast, no more than 30% of the Hartley guinea pigs died regardless of the virus dose. In lethally infected strain 13 guinea pigs, peak titers of virus (10(7) to 10(8) PFU) occurred in the spleen and lymph nodes at 8 to 9 days, in the salivary glands at 11 days, and in the lung at 14 to 16 days. Virus reached low titers (10(4) PFU) in the plasma and brain and intermediate titers in the liver, adrenal glands, kidney, pancreas, and heart. In moribund animals, the most consistent and severe histological lesion as an interstitial pneumonia. In contrast, the brain was only minimally involved. The immune response of lethally infected strain 13 guinea pigs, as measured by the indirect fluorescent antibody test, was detectable within 10 days of infection and was similar in timing and intensity to the fluorescent antibody test response of both lethally infected and surviving outbred animals. In contrast to the fluorescent antibody response, neutralizing antibody developed late in convalescence and was thus detected only in surviving outbred guinea pigs. The availability of a rodent model for human Lassa fever in uniformly susceptible strain 13 guinea pigs should facilitate detailed pathophysiological studies and efficacy testing of antiviral drugs, candidate vaccines, and immunotherapy regimens to develop control methods for this life-threatening disease in humans. Images PMID:6749685

  6. Virus-neutralizing antibody response of mice to consecutive infection with human and avian influenza A viruses.

    PubMed

    Janulíková, J; Stropkovská, A; Bobišová, Z; Košík, I; Mucha, V; Kostolanský, F; Varečková, E

    2015-06-01

    In this work we simulated in a mouse model a naturally occurring situation of humans, who overcame an infection with epidemic strains of influenza A, and were subsequently exposed to avian influenza A viruses (IAV). The antibody response to avian IAV in mice previously infected with human IAV was analyzed. We used two avian IAV (A/Duck/Czechoslovakia/1956 (H4N6) and the attenuated virus rA/Viet Nam/1203-2004 (H5N1)) as well as two human IAV isolates (virus A/Mississippi/1/1985 (H3N2) of medium virulence and A/Puerto Rico/8/1934 (H1N1) of high virulence). Two repeated doses of IAV of H4 or of H5 virus elicited virus-specific neutralizing antibodies in mice. Exposure of animals previously infected with human IAV (of H3 or H1 subtype) to IAV of H4 subtype led to the production of antibodies neutralizing H4 virus in a level comparable with the level of antibodies against the human IAV used for primary infection. In contrast, no measurable levels of virus-neutralizing (VN) antibodies specific to H5 virus were detected in mice infected with H5 virus following a previous infection with human IAV. In both cases the secondary infection with avian IAV led to a significant increase of the titer of VN antibodies specific to the corresponding human virus used for primary infection. Moreover, cross-reactive HA2-specific antibodies were also induced by sequential infection. By virtue of these results we suggest that the differences in the ability of avian IAV to induce specific antibodies inhibiting virus replication after previous infection of mice with human viruses can have an impact on the interspecies transmission and spread of avian IAV in the human population. PMID:26104333

  7. Emergence of CD4 Independence Envelopes and Astrocyte Infection in R5 Simian-Human Immunodeficiency Virus Model of Encephalitis

    PubMed Central

    Zhuang, Ke; Leda, Ana Rachel; Tsai, Lily; Knight, Heather; Harbison, Carole; Gettie, Agegnehu; Blanchard, James; Westmoreland, Susan

    2014-01-01

    ABSTRACT Human immunodeficiency virus type 1 (HIV-1) infection in the central nervous system (CNS) is characterized by replication in macrophages or brain microglia that express low levels of the CD4 receptor and is the cause of HIV-associated dementia and related cognitive and motor disorders that affect 20 to 30% of treatment-naive patients with AIDS. Independent viral envelope evolution in the brain has been reported, with the need for robust replication in resident CD4low cells, as well as CD4-negative cells, such as astrocytes, proposed as a major selective pressure. We previously reported giant-cell encephalitis in subtype B and C R5 simian-human immunodeficiency virus (SHIV)-infected macaques (SHIV-induced encephalitis [SHIVE]) that experienced very high chronic viral loads and progressed rapidly to AIDS, with varying degrees of macrophage or microglia infection and activation of these immune cells, as well as astrocytes, in the CNS. In this study, we characterized envelopes (Env) amplified from the brains of subtype B and C R5 SHIVE macaques. We obtained data in support of an association between severe neuropathological changes, robust macrophage and microglia infection, and evolution to CD4 independence. Moreover, the degree of Env CD4 independence appeared to correlate with the extent of astrocyte infection in vivo. These findings further our knowledge of the CNS viral population phenotypes that are associated with the severity of HIV/SHIV-induced neurological injury and improve our understanding of the mechanism of HIV-1 cellular tropism and persistence in the brain. IMPORTANCE Human immunodeficiency virus type 1 (HIV-1) infection of astrocytes in the brain has been suggested to be important in HIV persistence and neuropathogenesis but has not been definitively demonstrated in an animal model of HIV-induced encephalitis (HIVE). Here, we describe a new nonhuman primate (NHP) model of R5 simian-human immunodeficiency virus (SHIV)-induced encephalitis

  8. Considerations in the Use of Nonhuman Primate Models of Ebola Virus and Marburg Virus Infection.

    PubMed

    Geisbert, Thomas W; Strong, James E; Feldmann, Heinz

    2015-10-01

    The filoviruses, Ebola virus and Marburg virus, are zoonotic pathogens that cause severe hemorrhagic fever in humans and nonhuman primates (NHPs), with case-fatality rates ranging from 23% to 90%. The current outbreak of Ebola virus infection in West Africa, with >26 000 cases, demonstrates the long-underestimated public health danger that filoviruses pose as natural human pathogens. Currently, there are no vaccines or treatments licensed for human use. Licensure of any medical countermeasure may require demonstration of efficacy in the gold standard cynomolgus or rhesus macaque models of filovirus infection. Substantial progress has been made over the last decade in characterizing the filovirus NHP models. However, there is considerable debate over a variety of experimental conditions, including differences among filovirus isolates used, routes and doses of exposure, and euthanasia criteria, all of which may contribute to variability of results among different laboratories. As an example of the importance of understanding these differences, recent data with Ebola virus shows that an addition of a single uridine residue in the glycoprotein gene at the editing site attenuates the virus. Here, we draw on decades of experience working with filovirus-infected NHPs to provide a perspective on the importance of various experimental conditions. PMID:26063223

  9. CD8+ T cells control Ross River virus infection in musculoskeletal tissues of infected mice.

    PubMed

    Burrack, Kristina S; Montgomery, Stephanie A; Homann, Dirk; Morrison, Thomas E

    2015-01-15

    Ross River virus (RRV), chikungunya virus, and related alphaviruses cause debilitating polyarthralgia and myalgia. Mouse models of RRV and chikungunya virus have demonstrated a role for the adaptive immune response in the control of these infections. However, questions remain regarding the role for T cells in viral control, including the magnitude, location, and dynamics of CD8(+) T cell responses. To address these questions, we generated a recombinant RRV expressing the H-2(b)-restricted glycoprotein 33 (gp33) determinant derived from the glycoprotein of lymphocytic choriomeningitis virus. Using tetramers, we tracked gp33-specific CD8(+) T cells during RRV-lymphocytic choriomeningitis virus infection. We found that acute RRV infection induces activation of CD8(+) T cell responses in lymphoid and musculoskeletal tissues that peak from 10-14 d postinoculation, suggesting that CD8(+) T cells contribute to control of acute RRV infection. Mice genetically deficient for CD8(+) T cells or wild-type mice depleted of CD8(+) T cells had elevated RRV loads in skeletal muscle tissue, but not joint-associated tissues, at 14 d postinoculation, suggesting that the ability of CD8(+) T cells to control RRV infection is tissue dependent. Finally, adoptively transferred T cells were capable of reducing RRV loads in skeletal muscle tissue of Rag1(-/-) mice, indicating that T cells can contribute to the control of RRV infection in the absence of B cells and Ab. Collectively, these data demonstrate a role for T cells in the control of RRV infection and suggest that the antiviral capacity of T cells is controlled in a tissue-specific manner. PMID:25488988

  10. Hepatitis B virus coinfection in human immunodeficiency virus-infected patients: A review

    PubMed Central

    Sun, Hsin-Yun; Sheng, Wang-Huei; Tsai, Mao-Song; Lee, Kuan-Yeh; Chang, Sui-Yuan; Hung, Chien-Ching

    2014-01-01

    Hepatitis B virus (HBV) infection is a leading cause of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma worldwide. Due to the shared modes of transmission, coinfection with HBV and human immunodeficiency virus (HIV) is not uncommon. It is estimated that 10% of HIV-infected patients worldwide are coinfected with HBV. In areas where an HBV vaccination program is implemented, the HBV seroprevalence has declined significantly. In HIV/HBV-coinfected patients, HBV coinfection accelerates immunologic and clinical progression of HIV infection and increases the risk of hepatotoxicity when combination antiretroviral therapy (cART) is initiated, while HIV infection increases the risk of hepatitis events, cirrhosis, and end-stage liver disease related to chronic HBV infection. With the advances in antiviral therapy, concurrent, successful long-term suppression of HIV and HBV replication can be achieved in the cART era. To reduce the disease burden of HBV infection among HIV-infected patients, adoption of safe sex practices, avoidance of sharing needles and diluent, HBV vaccination and use of cART containing tenofovir disoproxil fumarate plus emtricitabine or lamivudine are the most effective approaches. However, due to HIV-related immunosuppression, using increased doses of HBV vaccine and novel approaches to HBV vaccination are needed to improve the immunogenicity of HBV vaccine among HIV-infected patients. PMID:25356024

  11. West Nile Virus Infection of Birds, Mexico

    PubMed Central

    Guerrero-Sánchez, Sergio; Cuevas-Romero, Sandra; Nemeth, Nicole M.; Trujillo-Olivera, María Teresa Jesús; Worwa, Gabriella; Dupuis, Alan; Brault, Aaron C.; Kramer, Laura D.; Komar, Nicholas

    2011-01-01

    West Nile virus (WNV) has caused disease in humans, equids, and birds at lower frequency in Mexico than in the United States. We hypothesized that the seemingly reduced virulence in Mexico was caused by attenuation of the Tabasco strain from southeastern Mexico, resulting in lower viremia than that caused by the Tecate strain from the more northern location of Baja California. During 2006–2008, we tested this hypothesis in candidate avian amplifying hosts: domestic chickens, rock pigeons, house sparrows, great-tailed grackles, and clay-colored thrushes. Only great-tailed grackles and house sparrows were competent amplifying hosts for both strains, and deaths occurred in each species. Tecate strain viremia levels were higher for thrushes. Both strains produced low-level viremia in pigeons and chickens. Our results suggest that certain avian hosts within Mexico are competent for efficient amplification of both northern and southern WNV strains and that both strains likely contribute to bird deaths. PMID:22172633

  12. Transcriptome analysis of the endangered Chinese giant salamander (Andrias davidianus): Immune modulation in response to Aeromonas hydrophila infection.

    PubMed

    Qi, Zhitao; Zhang, Qihuan; Wang, Zisheng; Ma, Tianyi; Zhou, Jie; Holland, Jason W; Gao, Qian

    2016-01-01

    The endangered Chinese giant salamander (Andrias davidianus) is the largest extant amphibian species. Disease outbreaks represent one of the major factors threatening A. davidianus populations in the wild and the viability of artificial breeding programmes. Development of future immune therapies to eliminate infectious disease in A. davidianus is dependent on a thorough understanding of the immune mechanisms elicited by pathogen encounters. To this end we have undertaken, for the first time in amphibians, differential transcriptome analysis of the giant salamander response to Aeromonas hydrophila, one of the most devastating pathogens affecting amphibian populations. Out of 87,204 non-redundant consensus unigenes 19,216 were annotated, 6834 of which were upregulated and 906 down-regulated following bacterial infection. 2058 unigenes were involved with immune system processes, including 287 differentially expressed unigenes indicative of the impact of bacterial infection on several innate and adaptive immune pathways in the giant salamander. Other pathways not directly associated with immune-related activity were differentially expressed, including developmental, structural, molecular and growth processes. Overall, this work provides valuable insights into the underlying immune mechanisms elicited during bacterial infection in amphibians that may aid in the future development of disease control measures in protecting the Chinese giant salamander. With the unique position of amphibians in the transition of tetrapods from aquatic to terrestrial habitats, our study will also be invaluable towards the further understanding of the evolution of tetrapod immunity. PMID:26620078

  13. Ferret hepatitis E virus infection induces acute hepatitis and persistent infection in ferrets.

    PubMed

    Li, Tian-Cheng; Yang, Tingting; Yoshizaki, Sayaka; Ami, Yasushi; Suzaki, Yuriko; Ishii, Koji; Kishida, Noriko; Shirakura, Masayuki; Asanuma, Hideki; Takeda, Naokazu; Wakita, Takaji

    2016-02-01

    Ferret hepatitis E virus (HEV), a novel hepatitis E virus, has been identified in ferrets. However, the pathogenicity of ferret HEV remains unclear. In the present study, we compared the HEV RNA-positivity rates and alanine aminotransferase (ALT) levels of 63 ferrets between before and after import from the US to Japan. We found that the ferret HEV-RNA positivity rates were increased from 12.7% (8/63) to 60.3% (38/63), and ALT elevation was observed in 65.8% (25/38) of the ferret HEV RNA-positive ferrets, indicating that ferret HEV infection is responsible for liver damage. From long term-monitoring of ferret HEV infection we determined that this infection in ferrets exhibits three patterns: sub-clinical infection, acute hepatitis, and persistent infection. The ALT elevation was also observed in ferret HEV-infected ferrets in a primary infection experiment. These results indicate that the ferret HEV infection induced acute hepatitis and persistent infection in ferrets, suggesting that the ferrets are a candidate animal model for immunological as well as pathological studies of hepatitis E. PMID:26790932

  14. Effects of Aging on Influenza Virus Infection Dynamics

    PubMed Central

    Hernandez-Vargas, Esteban A.; Wilk, Esther; Canini, Laetitia; Toapanta, Franklin R.; Binder, Sebastian C.; Uvarovskii, Alexey; Ross, Ted M.; Guzmán, Carlos A.

    2014-01-01

    ABSTRACT The consequences of influenza virus infection are generally more severe in individuals over 65 years of age (the elderly). Immunosenescence enhances the susceptibility to viral infections and renders vaccination less effective. Understanding age-related changes in the immune system is crucial in order to design prophylactic and immunomodulatory strategies to reduce morbidity and mortality in the elderly. Here, we propose different mathematical models to provide a quantitative understanding of the immune strategies in the course of influenza virus infection using experimental data from young and aged mice. Simulation results suggested a central role of CD8+ T cells for adequate viral clearance kinetics in young and aged mice. Adding the removal of infected cells by natural killer cells did not improve the model fit in either young or aged animals. We separately examined the infection-resistant state of cells promoted by the cytokines alpha/beta interferon (IFN-α/β), IFN-γ, and tumor necrosis factor alpha (TNF-α). The combination of activated CD8+ T cells with any of the cytokines provided the best fits in young and aged animals. During the first 3 days after infection, the basic reproductive number for aged mice was 1.5-fold lower than that for young mice (P < 0.05). IMPORTANCE The fits of our models to the experimental data suggest that the increased levels of IFN-α/β, IFN-γ, and TNF-α (the “inflammaging” state) promote slower viral growth in aged mice, which consequently limits the stimulation of immune cells and contributes to the reported impaired responses in the elderly. A quantitative understanding of influenza virus pathogenesis and its shift in the elderly is the key contribution of this work. PMID:24478442

  15. The influence of commensal bacteria on infection with enteric viruses.

    PubMed

    Karst, Stephanie M

    2016-04-01

    The intestinal microbiota exerts a marked influence in the mammalian host, both during homeostasis and disease. However, until very recently, there has been relatively little focus on the potential effect of commensal microorganisms on viral infection of the intestinal tract. In this Progress article, I review the recent advances that elucidate the mechanisms by which enteric viruses use commensal bacteria to enhance viral infectivity. These mechanisms segregate into two general categories: the direct facilitation of viral infection, including bacterial stabilization of viral particles and the facilitation of viral attachment to host target cells; and the indirect skewing of the antiviral immune response in a manner that promotes viral infection. Finally, I discuss the implications of these interactions for the development of vaccines and novel therapeutic approaches. PMID:26853118

  16. Treatment of Hepatitis C Virus Infection in Liver Transplant Recipients

    PubMed Central

    Suraweera, Duminda; Sundaram, Vinay

    2016-01-01

    Chronic hepatitis C virus (HCV) infection is the leading cause of liver transplantation in adults. Although the recurrence of HCV infection after liver transplantation is nearly universal, the recent advances in direct-acting antiviral (DAA) agents have revolutionized the management of HCV infection in the posttransplant setting. A number of these agents have been evaluated in recent clinical trials and have shown high sustained virologic response rates, shorter durations of treatment, and decreased adverse events when compared with the previous treatment of pegylated interferon and ribavirin. This article will review the current literature on the efficacy, tolerability, and potential drug interactions of various DAA agents in patients with recurrent HCV infection posttransplant. PMID:27330501

  17. EFFECT OF SIALODACRYOADENITIS VIRUS INFECTION ON AXONAL REGENERATION

    PubMed Central

    YU, VIVIAN M.; MACKINNON, SUSAN E.; HUNTER, DANIEL A.; BRENNER, MICHAEL J.

    2014-01-01

    The effect of sialodacryoadenitis virus (SDAV) infection on axonal regeneration and functional recovery was investigated in male Lewis rats. Animals underwent unilateral tibial nerve transection, immediate repair, and treatment with either FK506 (treated) or control vehicle (untreated). Serial walking track analyses were performed to assess functional recovery. Nerves were harvested for morphometric analysis on postoperative day 18 after an SDAV outbreak occurred that affected the 12 experimental animals. Histomorphometry and walking track data were compared against 36 historical controls. Rats infected with SDAV demonstrated severely impaired axonal regeneration and diminished functional recovery. Total fiber counts, nerve density, and percent neural tissue were all significantly reduced in infected animals (P < 0.05). Active SDAV infection severely impaired nerve regeneration and negated the positive effect of FK506 on nerve regeneration in rats. Immunosuppressive risks must be weighed carefully against the potential neuroregenerative benefits in the treatment of peripheral nerve injuries. PMID:21866574

  18. Renal involvement in feline immunodeficiency virus infection: a clinicopathological study.

    PubMed

    Poli, A; Abramo, F; Taccini, E; Guidi, G; Barsotti, P; Bendinelli, M; Malvaldi, G

    1993-01-01

    Renal tissues from 15 cats naturally infected with feline immunodeficiency virus (FIV) were examined histologically, immunohistochemically and ultrastructurally. Renal function and urinary proteins were also studied. Kidney abnormalities were found in 12 cats and were characterized by mesangial widening with segmental to diffuse glomerulosclerosis and presence of IgM and C3, and scanty IgG deposits in the mesangium. Tubulointerstitial lesions were also present. In 6 cats the lesions were severe enough to cause marked increase in blood urea nitrogen and creatinine, and heavy glomerular nonselective proteinuria. These findings suggest that a renal involvement is a frequent occurrence in FIV-infected cats. As the histopathological features observed were similar to those described in HIV-infected patients, FIV-infected cats may represent a valuable model for a better understanding of HIV-associated nephropathy in humans. PMID:8321363

  19. Epstein-Barr Virus Infection with Acute Acalculous Cholecystitis

    PubMed Central

    Kim, Ahlee; Moon, Jin Soo; Chang, Ju Young; Ko, Jae Sung

    2014-01-01

    Acute acalculous cholecystitis (AAC) is an inflammation of the gallbladder in the absence of demonstrated stones. AAC is frequently associated with severe systemic inflammation. However, the exact etiology and pathogenesis of AAC still remain unclear. Acute infection with Epstein Barr virus (EBV) in childhood is usually aymptomatic, whereas it often presents as typical infectious mononucleosis symptoms such as fever, cervical lymphadenopathy, and hepatosplenomegaly. AAC may occur during the course of acute EBV infection, which is rarely encountered in the pediatric population. AAC complicating the course of a primary EBV infection is usually associated with a favorable outcome. Most of the patients recover without any surgical treatment. Therefore, the detection of EBV in AAC would be important for prediction of better prognosis. We describe the case of a 10-year-old child who presented with AAC during the course of primary EBV infection, the first in Korea, and review the relevant literature. PMID:24749090

  20. Epstein-barr virus infection with acute acalculous cholecystitis.

    PubMed

    Kim, Ahlee; Yang, Hye Ran; Moon, Jin Soo; Chang, Ju Young; Ko, Jae Sung

    2014-03-01

    Acute acalculous cholecystitis (AAC) is an inflammation of the gallbladder in the absence of demonstrated stones. AAC is frequently associated with severe systemic inflammation. However, the exact etiology and pathogenesis of AAC still remain unclear. Acute infection with Epstein Barr virus (EBV) in childhood is usually aymptomatic, whereas it often presents as typical infectious mononucleosis symptoms such as fever, cervical lymphadenopathy, and hepatosplenomegaly. AAC may occur during the course of acute EBV infection, which is rarely encountered in the pediatric population. AAC complicating the course of a primary EBV infection is usually associated with a favorable outcome. Most of the patients recover without any surgical treatment. Therefore, the detection of EBV in AAC would be important for prediction of better prognosis. We describe the case of a 10-year-old child who presented with AAC during the course of primary EBV infection, the first in Korea, and review the relevant literature. PMID:24749090

  1. Systems biology unravels interferon responses to respiratory virus infections

    PubMed Central

    Kroeker, Andrea L; Coombs, Kevin M

    2014-01-01

    Interferon production is an important defence against viral replication and its activation is an attractive therapeutic target. However, it has long been known that viruses perpetually evolve a multitude of strategies to evade these host immune responses. In recent years there has been an explosion of information on virus-induced alterations of the host immune response that have resulted from data-rich omics technologies. Unravelling how these systems interact and determining the overall outcome of the host response to viral infection will play an important role in future treatment and vaccine development. In this review we focus primarily on the interferon pathway and its regulation as well as mechanisms by which respiratory RNA viruses interfere with its signalling capacity. PMID:24600511

  2. Tomato bushy stunt virus (TBSV) infecting Lycopersicon esculentum.

    PubMed

    Hafez, El Sayed E; Saber, Ghada A; Fattouh, Faiza A

    2010-01-01

    Tomato bushy stunt virus (TBSV) was detected in tomato crop (Lycopersicon esculentum) in Egypt with characteristic mosaic leaf deformation, stunting, and bushy growth symptoms. TBSV infection was confirmed serologically by ELISA and calculated incidence was 25.5%. Basic physicochemical properties of a purified TBSV Egh isolate were identical to known properties of tombusviruses of isometric 30-nm diameter particles, 41-kDa coat protein and the genome of approximately 4800 nt. This is the first TBSV isolate reported in Egypt. Cloning and partial sequencing of the isolate showed that it is more closely related to TBSV-P and TBSV-Ch than TBSV-Nf and TBSV-S strains of the virus. However, it is distinct from the above strains and could be a new strain of the virus which further confirms the genetic diversity of tombusviruses. PMID:21138066

  3. Modeling Influenza Virus Infection: A Roadmap for Influenza Research

    PubMed Central

    Boianelli, Alessandro; Nguyen, Van Kinh; Ebensen, Thomas; Schulze, Kai; Wilk, Esther; Sharma, Niharika; Stegemann-Koniszewski, Sabine; Bruder, Dunja; Toapanta, Franklin R.; Guzmán, Carlos A.; Meyer-Hermann, Michael; Hernandez-Vargas, Esteban A.

    2015-01-01

    Influenza A virus (IAV) infection represents a global threat causing seasonal outbreaks and pandemics. Additionally, secondary bacterial infections, caused mainly by Streptococcus pneumoniae, are one of the main complications and responsible for the enhanced morbidity and mortality associated with IAV infections. In spite of the significant advances in our knowledge of IAV infections, holistic comprehension of the interplay between IAV and the host immune response (IR) remains largely fragmented. During the last decade, mathematical modeling has been instrumental to explain and quantify IAV dynamics. In this paper, we review not only the state of the art of mathematical models of IAV infection but also the methodologies exploited for parameter estimation. We focus on the adaptive IR control of IAV infection and the possible mechanisms that could promote a secondary bacterial coinfection. To exemplify IAV dynamics and identifiability issues, a mathematical model to explain the interactions between adaptive IR and IAV infection is considered. Furthermore, in this paper we propose a roadmap for future influenza research. The development of a mathematical modeling framework with a secondary bacterial coinfection, immunosenescence, host genetic factors and responsiveness to vaccination will be pivotal to advance IAV infection understanding and treatment optimization. PMID:26473911

  4. Hepatitis C virus infection of human cytotrophoblasts cultured in vitro.

    PubMed

    Nie, Qing-He; Gao, Lu-Hua; Cheng, Yong-Qian; Huang, Xiao-Feng; Zhang, Ya-Fei; Luo, Xin-Dong; Wang, Jun-Qing; Wang, Yuan-Yuan

    2012-10-01

    Hepatitis C virus (HCV) infection in the uterus is a significant path of vertical HCV transmission. Some studies consider vertical HCV transmission in the uterus as the result of maternal blood leakage into infant blood, whereas others theorize that HCV is transmitted by the mother to the infant through cells constituting the placenta barrier. Although trophoblasts play an important role in the placenta barrier, no definitive evidence has been presented to prove that cytotrophoblasts can be infected with HCV. The current study investigated whether or not these can be infected with HCV by conducting an experiment, in which cultured human cytotrophoblasts were infected with HCV in vitro. The results were analyzed using reverse transcription polymerase chain reaction (RT-PCR), ultrastructural characteristic changes under an electron microscope, and immunoelectron microscopy. HCV RNA in the supernatant of the cultured medium of the infected group was intermittently detected during the 16-day incubation period using RT-PCR. Under an electron microscope, the ultrastructures of infected human cytotrophoblasts were markedly different from normal cells, demonstrating lysosomal hyperplasia, rough endoplasmic reticulum, decreased lipid droplets, presence of vacuoles, and the appearance of HCV-like particles. Using immunoelectron microscopy, HCV-like particles conjoined with golden granules were also observed. Based on the data, the current study concludes that HCV infects a human cytotrophoblast cultured in vitro; moreover, its ultrastructure changes dramatically upon infection. PMID:22930506

  5. A unicellular algal virus, Emiliania huxleyi virus 86, exploits an animal-like infection strategy.

    PubMed

    Mackinder, Luke C M; Worthy, Charlotte A; Biggi, Gaia; Hall, Matthew; Ryan, Keith P; Varsani, Arvind; Harper, Glenn M; Wilson, William H; Brownlee, Colin; Schroeder, Declan C

    2009-09-01

    Emiliania huxleyi virus 86 (EhV-86) belongs to the family Phycodnaviridae, a group of viruses that infect a wide range of freshwater and marine eukaryotic algae. Phycodnaviridae is one of the five families that belong to a large and phylogenetically diverse group of viruses known as nucleocytoplasmic large dsDNA viruses (NCLDVs). To date, our understanding of algal NCLDV entry is based on the entry mechanisms of members of the genera Chlorovirus and Phaeovirus, both of which consist of non-enveloped viruses that 'inject' their genome into their host via a viral inner-membrane host plasma membrane fusion mechanism, leaving an extracellular viral capsid. Using a combination of confocal and electron microscopy, this study demonstrated for the first time that EhV-86 differs from its algal virus counterparts in two fundamental areas. Firstly, its capsid is enveloped by a lipid membrane, and secondly, EhV-86 enters its host via either an endocytotic or an envelope fusion mechanism in which an intact nucleoprotein core still encapsulated by its capsid is seen in the host cytoplasm. Real-time fluorescence microscopy showed that viral internalization and virion breakdown took place within the host on a timescale of seconds. At around 4.5 h post-infection, virus progeny were released via a budding mechanism during which EhV-86 virions became enveloped with host plasma membrane. EhV-86 therefore appears to have an infection mechanism different from that employed by other algal NCLDVs, with entry and exit strategies showing a greater analogy to animal-like NCLDVs. PMID:19474246

  6. Characterisation of immunosuppression in rabbits after infection with myxoma virus.

    PubMed

    Jeklova, Edita; Leva, Lenka; Matiasovic, Jan; Kovarcik, Kamil; Kudlackova, Hana; Nevorankova, Zora; Psikal, Ivan; Faldyna, Martin

    2008-05-25

    Myxoma virus (MXV) causes the systemic disease myxomatosis in the European rabbit. Despite many in vitro studies on the function of MXV immunomodulatory proteins and detailed molecular knowledge of virus, little is known about the dynamics of interaction of the virus with the integrated host-immune system during infection. In this study changes in haematological profile, changes in lymphocyte subset distribution and non-specific proliferation activity of lymphocytes from different lymphoid compartments on the 2nd, 4th, 6th, 9th and 11th day after experimental infection of rabbits with MXV strain Lausanne was characterised. The relationship between alterations of immune parameters and dynamic of virus dissemination through the body was investigated. Haematological changes included moderate leucopenia with significant lymphopenia, neutrophilia, monocytosis and eosinopenia. A decrease of T cells including CD4+ and CD8+ and increase of CD79alpha+ were observed in draining popliteal lymph node 4 days after virus inoculation. From day 6, comparable changes were seen in collateral popliteal lymph node, spleen and peripheral blood. From day 9, the mentioned lymphocyte subsets tended to reach their original state in all of these lymphocyte compartments except draining popliteal lymph node. In thymus, MXV infection affected mainly CD4+CD8+ double positive thymocytes. On the other hand, proliferation activity of lymphocytes determined by the proliferation assay with plant-derived mitogens was significantly reduced from day 4 or 6 and remained reduced until the end of experiment in all observed lymphoid organs. Presence of MXV in respective lymphoid compartments preceded changes in lymphocyte subset distribution or lymphocyte activity. PMID:18222052

  7. Predicted pattern of Zika virus infection distribution with reference to rainfall in Thailand.

    PubMed

    Wiwanitkit, Somsri; Wiwanitkit, Viroj

    2016-07-01

    Zika virus infection is the present global medical problem. The disease appears in several countries around the world. The relationship between rainfall and occurrence of Zika virus infection was previously mentioned. Here, the authors use the mathematical modeling technique to reappraise on the previous data on immunoreactivity rate of Zika virus, dengue virus and Ckikungunya virus in Thailand and the reported interrelationship between arboviral infections and rainfall in Thailand for constructing of the predicted pattern of Zika virus distribution in Thailand. This data can be a useful tool for further disease surveillance in this area. PMID:27393105

  8. Genetic variation of occult hepatitis B virus infection

    PubMed Central

    Zhu, Hui-Lan; Li, Xu; Li, Jun; Zhang, Zhen-Hua

    2016-01-01

    Occult hepatitis B virus infection (OBI), characterized as the persistence of hepatitis B virus (HBV) surface antigen (HBsAg) seronegativity and low viral load in blood or liver, is a special form of HBV infection. OBI may be related mainly to mutations in the HBV genome, although the underlying mechanism of it remains to be clarified. Mutations especially within the immunodominant “α” determinant of S protein are “hot spots” that could contribute to the occurrence of OBI via affecting antigenicity and immunogenicity of HBsAg or replication and secretion of virion. Clinical reports account for a large proportion of previous studies on OBI, while functional analyses, especially those based on full-length HBV genome, are rare. PMID:27053845

  9. Current treatments for chronic hepatitis B virus infections.

    PubMed

    Zoulim, Fabien; Lebossé, Fanny; Levrero, Massimo

    2016-06-01

    Over 240 million people worldwide are chronically infected with hepatitis B virus (HBV) and although a prophylactic vaccine and effective antiviral therapies are available, no cure exists. Curative regimens are urgently needed because up to one million deaths per year are caused by HBV-related liver cancer and end-stage liver disease. HBV is an hepatotropic virus which belongs to the Hepadnaviridae family and replicates its DNA genome via a reverse transcriptase mechanism. Effective therapies have been developed for chronic hepatitis B (CHB) infection in the last two decades. They rely on the use of interferon alpha and its pegylated formulation, and on nucleos(t)ide analogs that inhibit viral polymerase activity. Their results are discussed in this review as well as future perspectives. PMID:27318098

  10. Detection of Zika Virus Infection in Thailand, 2012–2014

    PubMed Central

    Buathong, Rome; Hermann, Laura; Thaisomboonsuk, Butsaya; Rutvisuttinunt, Wiriya; Klungthong, Chonticha; Chinnawirotpisan, Piyawan; Manasatienkij, Wudtichai; Nisalak, Ananda; Fernandez, Stefan; Yoon, In-Kyu; Akrasewi, Passakorn; Plipat, Tanarak

    2015-01-01

    Zika virus (ZIKV) is an emerging mosquito-borne pathogen with reported cases in Africa, Asia, and large outbreaks in the Pacific. No autochthonous ZIKV infections have been confirmed in Thailand. However, there have been several cases reported in travelers returning from Thailand. Here we report seven cases of acute ZIKV infection in Thai residents across the country confirmed by molecular or serological testing including sequence data. These endemic cases, combined with previous reports in travelers, provide evidence that ZIKV is widespread throughout Thailand. PMID:26101272

  11. Human Immunodeficiency Virus Infection: The Spectrum Beyond AIDS

    PubMed Central

    Willoughby, Brain C.

    1987-01-01

    Since 1981, the Acquired Immune Deficiency Syndrome (AIDS) has emerged as the major infectious epidemic of our time. It is the most profound manifestation of infection with the Human Immunodeficiency Virus (HIV). Since 1984, serologic methods have existed to detect antibody to HIV. Several other clinical entities have been detected and are attributable to HIV infection. Appropriate counsel must accompany antibody testing. The author discusses the acute seroconversion event, as well as asymptomatic carrier status, including generalized lymphadenopathy. He also reviews the symptomatic states that do not meet the surveillance definition of AIDS, including treatments where available. PMID:21263801

  12. Epidemiology and prevention of hepatitis B virus infection

    PubMed Central

    Kwon, So Young

    2011-01-01

    Hepatitis B virus (HBV) infection has been a major global cause of morbidity and mortality. The recognition of the problem led to a worldwide effort to reduce transmission of HBV through routine infant vaccination. HBV infection is the most common cause of chronic liver diseases and hepatocellular carcinoma in Korea. After hepatitis B vaccine era, seroprevalence of hepatits B surface antigen is decreasing, particularly in children. Hepatitis B vaccine is remarkably safe and shows high immunogenicity. Universal childhood immunization with three doses of hepatitis B vaccine in the first year of life is a highly effective method for prevention and control of hepatitis B. PMID:21757978

  13. Antiretroviral Therapy for Prevention of Human Immunodeficiency Virus Infection.

    PubMed

    Kalapila, Aley G; Marrazzo, Jeanne

    2016-07-01

    Human immunodeficiency virus (HIV) infection is considered a chronic medical condition. Several new drugs are available, including fixed-dose combination tablets, that have greatly simplified combination antiretroviral therapy (ART) regimens to treat HIV, while increasing the life-expectancy of infected individuals. In the last decade, multiple well-regarded studies have established the benefits of using ART in high-risk, HIV-negative persons to prevent HIV acquisition. The primary care provider must not only understand commonly encountered issues pertaining to ART, such as toxicities and drug interactions, but also needs to be aware of using ART for HIV prevention. PMID:27235622

  14. Care of the Human Immunodeficiency Virus-Infected Menopausal Woman

    PubMed Central

    Cejtin, Helen E.

    2012-01-01

    More women than ever before are both Human Immunodeficiency Virus-infected and menopausal, because of increased survival and more frequent diagnosis in older women. Such a woman has the combined burden of her infection, its treatment, comorbid conditions, and aging. Thus she is at risk for a variety of problems such as disorders of bone mineral density and deficiencies in cognitive functioning. In addition to this, she experiences menopause in a unique fashion, with more symptoms and perhaps at an earlier age. The clinician caring for her must take a proactive approach to this multitude of factors that may affect her health and well-being. PMID:22284959

  15. Hepatitis B and hepatitis delta virus infection in South America.

    PubMed Central

    Torres, J R

    1996-01-01

    About 100,000 cases of acute hepatitis B virus (HBV) infection occur annually in South America. The overall prevalence of HBV infection in low risk populations ranges from 6.7% to 41%, while hepatitis B surface antigen (HBsAg) rates range from 0.4% to 13%. In high endemicity aboriginal or rural populations, perinatal transmission may play a major part in the spread of HBV. In urban populations, however, horizontal transmission, probably by sexual contact, is the predominant mode of spread, with higher rates of HBV positivity in lower socioeconomic groups. High risk populations such as health care workers and haemodialysis patients show higher rates of HBV infection than comparable populations elsewhere. The risk of posttransfusion hepatitis B remains high in some areas. Concomitant HBV infection may accelerate the chronic liver disease seen in decompensated hepatosplenic schistosomiasis. In the north, the prevalence of hepatitis delta virus (HDV) infection ranks among the highest in the world. In the south, the problem appears negligible although it is increasing within high risk urban communities. HDV superinfection has been the cause of large outbreaks of fulminant hepatitis. The cost of comprehensive or mass vaccination programmes remains unaffordable for most South American countries. Less expensive alternatives such as low dose intradermal schedules of immunisation have been used with success in selected adult subjects. PMID:8786054

  16. Evidence of Apis cerana Sacbrood virus Infection in Apis mellifera.

    PubMed

    Gong, Hong-Ri; Chen, Xiu-Xian; Chen, Yan Ping; Hu, Fu-Liang; Zhang, Jiang-Lin; Lin, Zhe-Guang; Yu, Ji-Wei; Zheng, Huo-Qing

    2016-04-15

    Sacbrood virus(SBV) is one of the most destructive viruses in the Asian honeybeeApis ceranabut is much less destructive inApis mellifera In previous studies, SBV isolates infectingA. cerana(AcSBV) and SBV isolates infectingA. mellifera(AmSBV) were identified as different serotypes, suggesting a species barrier in SBV infection. In order to investigate this species isolation, we examined the presence of SBV infection in 318A. melliferacolonies and 64A. ceranacolonies, and we identified the genotypes of SBV isolates. We also performed artificial infection experiments under both laboratory and field conditions. The results showed that 38A. melliferacolonies and 37A. ceranacolonies were positive for SBV infection. Phylogenetic analysis based on RNA-dependent RNA polymerase (RdRp) gene sequences indicated thatA. ceranaisolates and mostA. melliferaisolates formed two distinct clades but two strains isolated fromA. melliferawere clustered with theA. ceranaisolates. In the artificial-infection experiments, AcSBV negative-strand RNA could be detected in both adult bees and larvae ofA. mellifera, although there were no obvious signs of the disease, demonstrating the replication of AcSBV inA. mellifera Our results suggest that AcSBV is able to infectA. melliferacolonies with low prevalence (0.63% in this study) and pathogenicity. This work will help explain the different susceptibilities ofA. ceranaandA. melliferato sacbrood disease and is potentially useful for guiding beekeeping practices. PMID:26801569

  17. Virus Competition for Shedding and Tumor Formation Over Time in Marek's Disease Virus Dual-infected Chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was designed to determine what effect multiple virulent Marek’s disease viruses have on each other over time during dual-infection. Serotype 1 viruses able to be differentiated were administered either simultaneously or with a short (24 hours) or long (13 days) interval. Virus frequency ...

  18. Characterisation of DNA forms associated with cassava latent virus infection.

    PubMed Central

    Stanley, J; Townsend, R

    1985-01-01

    In addition to the major encapsidated DNA species found in preparations of cassava latent virus (genomic DNAs 1 and 2) there are minor DNA populations of twice (dimeric) and approximately half genome length. Both minor species resemble the genomic DNAs in that they are composed of predominantly circular single-stranded DNA. All of these size groups have a corresponding covalently-closed circular double-stranded DNA form in infected tissue. Infectivity studies using cloned DNAs 1 and 2 show that dimeric DNA routinely appears, suggesting it to be an intermediate in the DNA replicative cycle that can be encapsidated at low efficiency. In contrast, half unit length DNA has not yet been detected after multiple passaging of virus derived from the cloned DNA inoculum. Half unit length DNAs appear to be derived exclusively from DNA 2 and consist of a population of molecules exhibiting a relatively specific deletion. As they have an inhibitory effect on virus multiplication, their encapsidated forms are analogous to defective interfering particles associated with other eukaryotic DNA containing viruses. Small primer molecules associated with the genomic single-stranded DNAs, as reported for another geminivirus, have not been detected in CLV. Images PMID:4000956

  19. [Epidemiology of hepatitis E virus infection in Spain].

    PubMed

    Echevarría, José Manuel; Fogeda, Marta; Avellón, Ana

    2015-04-01

    The general features of the epidemiology and ecology of hepatitis E virus in Spain are already known after 20 years of investigations. Genotype 3 strains, mainly from sub-genotype 3f, circulated among swine livestock and certain wild mammals, and would be sporadically transmitted to humans through direct contact with the reservoirs or by consumption of foods derived from them. Bivalve shellfish contaminated by hepatitis E virus from sewage could also play a role in transmission. Although the interpretation of results from seroprevalence studies in low endemic settings is still controversial, antibody to hepatitis E virus displays an overall prevalence less than 10% among the population of Spain, increasing significantly with age. From the, approximately, 150 cases of acute hepatitis E recorded in the international literature, males older than 40 years, suffering a mild, locally acquired disease predominate. In addition, hepatitis E might be more frequent in the North of the country than in other regions. Although the disease does not usually have a great clinical relevance, the occasional finding of cases of fulminant hepatitis, and of ribavirin-resistant, chronic hepatitis E virus infections among the immunocompromised would recommend the surveillance of the infection by the public health authority and a better implementation of specific diagnostic procedures in clinical laboratories. PMID:24447919

  20. Small RNA profiles from virus-infected fresh market vegetables.

    PubMed

    Frizzi, Alessandra; Zhang, Yuanji; Kao, John; Hagen, Charles; Huang, Shihshieh

    2014-12-10

    Functional small RNAs, such as short interfering RNAs (siRNAs) and microRNAs (miRNAs), exist in freshly consumed fruits and vegetables. These siRNAs can be derived either from endogenous sequences or from viruses that infect them. Symptomatic tomatoes, watermelons, zucchini, and onions were purchased from grocery stores and investigated by small RNA sequencing. By aligning the obtained small RNA sequences to sequences of known viruses, four different viruses were identified as infecting these fruits and vegetables. Many of these virally derived small RNAs along with endogenous small RNAs were found to be highly complementary to human genes. However, the established history of safe consumption of these vegetables suggests that this sequence homology has little biological relevance. By extension, these results provide evidence for the safe use by humans and animals of genetically engineered crops using RNA-based suppression technologies, especially vegetable crops with virus resistance conferred by expression of siRNAs or miRNAs derived from viral sequences. PMID:25389086

  1. [IMMUNOPATHOGENESIS OF OCCULT INFECTION CAUSED BY HEPATITIS B VIRUS].

    PubMed

    Semenenko, T A; Suslov, A P

    2015-01-01

    The concept of occult infection caused by hepatitis B virus (HBV) is determined as the presence of HBV DNA in blood sera or liver with the absence of detectable HBsAg. The actuality of this problem is associated with the fact, that occult hepatitis B (OHB) can be transmitted during hemotransfusions, cause reactivation of chronic hepatitis B in immune compromised individuals, facilitate development of liver cirrhosis and hepatocellular carcinoma. Several different hypotheses of OHB immunopathogenesis have been proposed, including a low number of copies of HBV DNA, altered immune response of the macroorganism, genetic variability of the S gene, integration of viral DNA into host genome, infection of mononuclear cells of peripheral blood, presence of immune complexes that hide HBsAg, and interference by other viruses such as HCV and HIV. Molecular mechanisms of HBV virus in HBsAg-negative individuals are not fully understood, however, viral mutations seem a very significant factor. Approaches of OHB prophylaxis including use of a polyvalent vaccine, that allows vaccination against wild and mutant HBV viruses, are examined. PMID:26950999

  2. Neurocysticercosis and human immunodeficiency virus infection: a case report.

    PubMed

    Chianura, Leonardo; Sberna, Maurizio; Moioli, Cristina; Villa, Maria Riccarda; Orcese, Carloandrea; Causarano, Renzo

    2006-01-01

    Ecuador is considered a holoendemic high-risk area for the transmission of cysticercosis. Moreover, the progression of human immunodeficiency virus (HIV) occurs worldwide. We present a case of simultaneous diagnosis of cysticercosis and HIV infection in a 22-year-old Ecuadorian immigrant. We would postulate that with the increasing HIV incidence in endemic areas of cysticercosis, the simultaneous diagnosis of both diseases is an event to be expected. PMID:17107432

  3. [Lopinavir/ritonavir in human immunodeficiency virus-infected women].

    PubMed

    Téllez, María Jesús

    2014-11-01

    There are clear sex-related biological differences between men and women. Diseases that affect the two sexes differently are studied separately. However, some diseases affect both men and women, but their incidence or outcome are clearly different. In human immunodeficiency virus infection, the potential differences in the effects of antiretroviral therapy are poorly characterized and few studies have been designed to elucidate these differences. Moreover, women are usually poorly represented in clinical trials of antiretroviral drugs. PMID:25542872

  4. [Epstein-Barr virus infections in adults: a diagnostic challenge].

    PubMed

    Goltzman, G; Nagornov, S; Horwitz, M; Rapoport, M J

    2000-04-16

    The adult form of mononucleosis caused by Ebstein-Barr virus (EBV) is different from the disease in children and adolescents. In most adults there is no pharyngitis or lymphadenopathy, fever is much more prolonged, abnormal liver function is frequent and lymphocytosis and the presence of atypical lymphocytes are not common. Such an atypical disease presentation often results in delayed diagnosis and unnecessary treatments. We describe 2 adults with such atypical presentations and complications of EBV infection. PMID:10883203

  5. Isolation and complete genome sequencing of Mimivirus bombay, a Giant Virus in sewage of Mumbai, India.

    PubMed

    Chatterjee, Anirvan; Ali, Farhan; Bange, Disha; Kondabagil, Kiran

    2016-09-01

    We report the isolation and complete genome sequencing of a new Mimiviridae family member, infecting Acanthamoeba castellanii, from sewage in Mumbai, India. The isolated virus has a particle size of about 435 nm and a 1,182,200-bp genome. A phylogeny based on the DNA polymerase sequence placed the isolate as a new member of the Mimiviridae family lineage A and was named as Mimivirus bombay. Extensive presence of Mimiviridae family members in different environmental niches, with remarkably similar genome size and genetic makeup, point towards an evolutionary advantage that needs to be further investigated. The complete genome sequence of Mimivirus bombay was deposited at GenBank/EMBL/DDBJ under the accession number KU761889. PMID:27330993

  6. Ebola virus-like particles protect from lethal Ebola virus infection

    PubMed Central

    Warfield, Kelly L.; Bosio, Catharine M.; Welcher, Brent C.; Deal, Emily M.; Mohamadzadeh, Mansour; Schmaljohn, Alan; Aman, M. Javad; Bavari, Sina

    2003-01-01

    The filovirus Ebola causes hemorrhagic fever with 70–80% human mortality. High case-fatality rates, as well as known aerosol infectivity, make Ebola virus a potential global health threat and possible biological warfare agent. Development of an effective vaccine for use in natural outbreaks, response to biological attack, and protection of laboratory workers is a higher national priority than ever before. Coexpression of the Ebola virus glycoprotein (GP) and matrix protein (VP40) in mammalian cells results in spontaneous production and release of virus-like particles (VLPs) that resemble the distinctively filamentous infectious virions. VLPs have been tested and found efficacious as vaccines for several viruses, including papillomavirus, HIV, parvovirus, and rotavirus. Herein, we report that Ebola VLPs (eVLPs) were immunogenic in vitro as eVLPs matured and activated mouse bone marrow-derived dendritic cells, assessed by increases in cell-surface markers CD40, CD80, CD86, and MHC class I and II and secretion of IL-6, IL-10, macrophage inflammatory protein (MIP)-1α, and tumor necrosis factor α by the dendritic cells. Further, vaccinating mice with eVLPs activated CD4+ and CD8+ T cells, as well as CD19+ B cells. After vaccination with eVLPs, mice developed high titers of Ebola virus-specific antibodies, including neutralizing antibodies. Importantly, mice vaccinated with eVLPs were 100% protected from an otherwise lethal Ebola virus inoculation. Together, our data suggest that eVLPs represent a promising vaccine candidate for protection against Ebola virus infections and a much needed tool to examine the genesis and nature of immune responses to Ebola virus. PMID:14673108

  7. Decreased virus population diversity in p53-null mice infected with weakly oncogenic Abelson virus.

    PubMed

    Marchlik, Erica; Kalman, Richard; Rosenberg, Naomi

    2005-09-01

    The Abelson murine leukemia virus (Ab-MLV), like other retroviruses that contain v-onc genes, arose following a recombination event between a replicating retrovirus and a cellular oncogene. Although experimentally validated models have been presented to address the mechanism by which oncogene capture occurs, very little is known about the events that influence emerging viruses following the recombination event that incorporates the cellular sequences. One feature that may play a role is the genetic makeup of the host in which the virus arises; a number of host genes, including oncogenes and tumor suppressor genes, have been shown to affect the pathogenesis of many murine leukemia viruses. To examine how a host gene might affect an emerging v-onc gene-containing retrovirus, we studied the weakly oncogenic Ab-MLV-P90A strain, a mutant that generates highly oncogenic variants in vivo, and compared the viral populations in normal mice and mice lacking the p53 tumor suppressor gene. While variants arose in both p53+/+ and p53-/- tumors, the samples from the wild-type animals contained a more diverse virus population. Differences in virus population diversity were not observed when wild-type and null animals were infected with a highly oncogenic wild-type strain of Ab-MLV. These results indicate that p53, and presumably other host genes, affects the selective forces that operate on virus populations in vivo and likely influences the evolution of oncogenic retroviruses such as Ab-MLV. PMID:16140739

  8. Active NF-kappaB signalling is a prerequisite for influenza virus infection.

    PubMed

    Nimmerjahn, Falk; Dudziak, Diana; Dirmeier, Ulrike; Hobom, Gerd; Riedel, Alexander; Schlee, Martin; Staudt, Louis M; Rosenwald, Andreas; Behrends, Uta; Bornkamm, Georg W; Mautner, Josef

    2004-08-01

    Influenza virus still poses a major threat to human health. Despite widespread vaccination programmes and the development of drugs targeting essential viral proteins, the extremely high mutation rate of influenza virus still leads to the emergence of new pathogenic virus strains. Therefore, it has been suggested that cellular cofactors that are essential for influenza virus infection might be better targets for antiviral therapy. It has previously been reported that influenza virus efficiently infects Epstein-Barr virus-immortalized B cells, whereas Burkitt's lymphoma cells are virtually resistant to infection. Using this cellular system, it has been shown here that an active NF-kappaB signalling pathway is a general prerequisite for influenza virus infection of human cells. Cells with low NF-kappaB activity were resistant to influenza virus infection, but became susceptible upon activation of NF-kappaB. In addition, blocking of NF-kappaB activation severely impaired influenza virus infection of otherwise highly susceptible cells, including the human lung carcinoma cell lines A549 and U1752 and primary human cells. On the other hand, infection with vaccinia virus was not dependent on an active NF-kappaB signalling pathway, demonstrating the specificity of this pathway for influenza virus infection. These results might be of major importance for both the development of new antiviral therapies and the understanding of influenza virus biology. PMID:15269376

  9. Cross-species infection of Deformed Wing virus poses a new threat to pollinator conservation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Here we provide the evidence that Deformed Wing Virus (DWV), one of the most prevalent and common viruses in honey bees Apis mellifera, could cause an infection in bumble bees, Bombus huntii and that the virus infection could spread over the entire body of B. huntii. Our results showed that gut of...

  10. Gene expression responses to highly pathogenic avian influenza H5N1 virus infections in ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Differences in host response to infection with avian influenza (AI) viruses were investigated by identifying genes differentially expressed in tissues of infected ducks. Clear differences in pathogenicity were observed among ducks inoculated with five H5N1 HPAI viruses. Virus titers in tissues cor...

  11. [Significance of PRRS virus infections for respiratory tract infections in swine--a literature review].

    PubMed

    Grosse Beilage, E

    1995-12-01

    The paper summarises present knowledge concerning the possible role of a virus which has in the meantime been classified as belonging to the arteriviridae and which causes PRRS (Porcine Reproductive and Respiratory Syndrome), in the pathogenesis of respiratory diseases four years after first isolation of the virus. Although the fact that PRRSV-infection produces an immunity which protects swine from repeated bouts of PRRSV is common knowledge by now, reinfection with the virus might be possible. An immunosuppression, which has been suggested by many investigators, and which was thought to be the result of destruction of alveolar macrophages during virus replication, was not found as yet. The significance of the extent and the duration of the decrease in the number of alveolar macrophages, which belong to the unspecific immunity, for the total immune system of swine infected with PRRSV remains unclear. A general impairment of specific immunity through PRRSV-infection could not be shown. The present role of PRRS for the pathogenesis of respiratory disease is seen very differently. The significance of PRRSV as primary cause of an "influenza-like" illness which is principally followed by severe bacterial infection of the respiratory tract, is questioned by the results of studies which identify PRRSV-infection as a mainly subclinical disease. In these studies, clinical cases are the exemption. Attempts at experimental reproduction of a clinically manifest, respiratory disease was not successful as yet. The paper describes factors which might be responsible for these variable results. Control of PRRS is difficult in areas with a high density of the swine population, since the spreading of the virus with the wind seems to be important besides the recruitment of new, infected animals. A vaccine has not yet been registered in Germany. First experimental experiences with vaccination are available from Denmark and the USA. PMID:8591744

  12. Neurological Complications of Ebola Virus Infection.

    PubMed

    Billioux, Bridgette Jeanne; Smith, Bryan; Nath, Avindra

    2016-07-01

    Ebola virus disease is one of the deadliest pathogens known to man, with a mortality rate between 25-90% depending on the species and outbreak of Ebola. Typically, it presents with fever, headache, voluminous vomiting and diarrhea, and can progress to a hemorrhagic illness; neurologic symptoms, including meningoencephalitis, seizures, and coma, can also occur. Recently, an outbreak occurred in West Africa, affecting > 28,000 people, and killing > 11,000. Owing to the magnitude of this outbreak, and the large number (>17,000) of Ebola survivors, the medical and scientific communities are learning much more about the acute manifestations and sequelae of Ebola. A number of neurologic complications can occur after Ebola, such as seizures, memory loss, headaches, cranial nerve abnormalities, and tremor. Ebola may also persist in some immunologically privileged sites, including the central nervous system, and can rarely lead to relapse in disease. Owing to these findings, it is important that survivors are evaluated and monitored for neurologic symptoms. Much is unknown about this disease, and treatment remains largely supportive; however, with ongoing clinical and basic science, the mechanisms of how Ebola affects the central nervous system and how it persists after acute disease will hopefully become more clear, and better treatments and clinical practices for Ebola patients will be developed. PMID:27412684

  13. Hepatitis C virus (HCV) and human immunodeficiency virus type 1 (HIV-1) infections in alcoholics.

    PubMed

    Prakash, Om; Mason, Andrew; Luftig, Ronald B; Bautista, Abraham P

    2002-07-01

    Approximately 400,000 individuals in the United States are co-infected with hepatitis C virus (HCV) and human immunodeficiency virus type 1 (HIV-1) and it is likely that almost one in two of these subjects consumes alcohol. The majority of these patients suffer an accelerated course of liver disease as manifested by the onset of cirrhosis within 5 to 10 years of developing HCV infection, as well as an increased risk of developing hepatocellular carcinoma (HCC). It is thought that chronic alcohol abuse mediates liver damage as a result of increased production of free radicals and proinflammatory cytokines. In the setting of chronic HCV infection, alcohol ingestion has an additional effect of diminishing immune clearance and increasing viral burden to hasten the onset of cirrhosis and HCC. Likewise, chronic HCV and HIV-1 co-infection results in a net increase in HCV burden; higher prevalence rates of HCV transmission to sexual partners and offspring, as well as an accelerated progression to end stage liver disease as compared to individuals with HCV infection alone. Thus, the synergistic effects of alcohol abuse and HIV-1 greatly impact on the morbidity and mortality for patients with HCV coinfection. Ultimately, this cumulative disease process will require far more aggressive management with abstinence and counseling for alcohol abuse; highly active antiretroviral therapy (HAART) for HIV infection and combination anti-viral therapy for HCV infection to stem the rapid progression to end stage liver disease. PMID:12086918

  14. Drug repurposing of minocycline against dengue virus infection.

    PubMed

    Leela, Shilpa Lekshmi; Srisawat, Chatchawan; Sreekanth, Gopinathan Pillai; Noisakran, Sansanee; Yenchitsomanus, Pa-Thai; Limjindaporn, Thawornchai

    2016-09-01

    Dengue virus infection is one of the most common arthropod-borne viral diseases. A complex interplay between host and viral factors contributes to the severity of infection. The antiviral effects of three antibiotics, lomefloxacin, netilmicin, and minocycline, were examined in this study, and minocycline was found to be a promising drug. This antiviral effect was confirmed in all four serotypes of the virus. The effects of minocycline at various stages of the viral life cycle, such as during viral RNA synthesis, intracellular envelope protein expression, and the production of infectious virions, were examined and found to be significantly reduced by minocycline treatment. Minocycline also modulated host factors, including the phosphorylation of extracellular signal-regulated kinase1/2 (ERK1/2). The transcription of antiviral genes, including 2'-5'-oligoadenylate synthetase 1 (OAS1), 2'-5'-oligoadenylate synthetase 3 (OAS3), and interferon α (IFNA), was upregulated by minocycline treatment. Therefore, the antiviral activity of minocycline may have a potential clinical use against Dengue virus infection. PMID:27396621

  15. A dual drug regimen synergistically blocks human parainfluenza virus infection

    PubMed Central

    Bailly, Benjamin; Dirr, Larissa; El-Deeb, Ibrahim M.; Altmeyer, Ralf; Guillon, Patrice; von Itzstein, Mark

    2016-01-01

    Human parainfluenza type-3 virus (hPIV-3) is one of the principal aetiological agents of acute respiratory illness in infants worldwide and also shows high disease severity in the elderly and immunocompromised, but neither therapies nor vaccines are available to treat or prevent infection, respectively. Using a multidisciplinary approach we report herein that the approved drug suramin acts as a non-competitive in vitro inhibitor of the hPIV-3 haemagglutinin-neuraminidase (HN). Furthermore, the drug inhibits viral replication in mammalian epithelial cells with an IC50 of 30 μM, when applied post-adsorption. Significantly, we show in cell-based drug-combination studies using virus infection blockade assays, that suramin acts synergistically with the anti-influenza virus drug zanamivir. Our data suggests that lower concentrations of both drugs can be used to yield high levels of inhibition. Finally, using NMR spectroscopy and in silico docking simulations we confirmed that suramin binds HN simultaneously with zanamivir. This binding event occurs most likely in the vicinity of the protein primary binding site, resulting in an enhancement of the inhibitory potential of the N-acetylneuraminic acid-based inhibitor. This study offers a potentially exciting avenue for the treatment of parainfluenza infection by a combinatorial repurposing approach of well-established approved drugs. PMID:27053240

  16. A dual drug regimen synergistically blocks human parainfluenza virus infection

    NASA Astrophysics Data System (ADS)

    Bailly, Benjamin; Dirr, Larissa; El-Deeb, Ibrahim M.; Altmeyer, Ralf; Guillon, Patrice; von Itzstein, Mark

    2016-04-01

    Human parainfluenza type-3 virus (hPIV-3) is one of the principal aetiological agents of acute respiratory illness in infants worldwide and also shows high disease severity in the elderly and immunocompromised, but neither therapies nor vaccines are available to treat or prevent infection, respectively. Using a multidisciplinary approach we report herein that the approved drug suramin acts as a non-competitive in vitro inhibitor of the hPIV-3 haemagglutinin-neuraminidase (HN). Furthermore, the drug inhibits viral replication in mammalian epithelial cells with an IC50 of 30 μM, when applied post-adsorption. Significantly, we show in cell-based drug-combination studies using virus infection blockade assays, that suramin acts synergistically with the anti-influenza virus drug zanamivir. Our data suggests that lower concentrations of both drugs can be used to yield high levels of inhibition. Finally, using NMR spectroscopy and in silico docking simulations we confirmed that suramin binds HN simultaneously with zanamivir. This binding event occurs most likely in the vicinity of the protein primary binding site, resulting in an enhancement of the inhibitory potential of the N-acetylneuraminic acid-based inhibitor. This study offers a potentially exciting avenue for the treatment of parainfluenza infection by a combinatorial repurposing approach of well-established approved drugs.

  17. A dual drug regimen synergistically blocks human parainfluenza virus infection.

    PubMed

    Bailly, Benjamin; Dirr, Larissa; El-Deeb, Ibrahim M; Altmeyer, Ralf; Guillon, Patrice; von Itzstein, Mark

    2016-01-01

    Human parainfluenza type-3 virus (hPIV-3) is one of the principal aetiological agents of acute respiratory illness in infants worldwide and also shows high disease severity in the elderly and immunocompromised, but neither therapies nor vaccines are available to treat or prevent infection, respectively. Using a multidisciplinary approach we report herein that the approved drug suramin acts as a non-competitive in vitro inhibitor of the hPIV-3 haemagglutinin-neuraminidase (HN). Furthermore, the drug inhibits viral replication in mammalian epithelial cells with an IC50 of 30 μM, when applied post-adsorption. Significantly, we show in cell-based drug-combination studies using virus infection blockade assays, that suramin acts synergistically with the anti-influenza virus drug zanamivir. Our data suggests that lower concentrations of both drugs can be used to yield high levels of inhibition. Finally, using NMR spectroscopy and in silico docking simulations we confirmed that suramin binds HN simultaneously with zanamivir. This binding event occurs most likely in the vicinity of the protein primary binding site, resulting in an enhancement of the inhibitory potential of the N-acetylneuraminic acid-based inhibitor. This study offers a potentially exciting avenue for the treatment of parainfluenza infection by a combinatorial repurposing approach of well-established approved drugs. PMID:27053240

  18. Measles Virus Infection Among Vaccinated and Unvaccinated Children in Nigeria

    PubMed Central

    Adeniji, Johnson A.; Olusola, Babatunde A.; Motayo, Babatunde O.; Akintunde, Grace B.

    2015-01-01

    Abstract This study investigated measles infection in vaccinated and unvaccinated children presenting with fever and maculopapular rash during measles outbreaks in the southern and western states of Nigeria. Measles, an acute viral illness caused by a virus in the family Paramyxoviridae, is a vaccine-preventable disease. Measles outbreak is common in Nigeria, despite the national immunization program. Children presenting with symptoms of measles infection in general hospitals and health centers in the states of southern and western Nigeria were recruited for this study. Vaccination history, clinical details, and 5 mL of blood were obtained from the children. Their sera samples were screened for specific immunoglobulin M antibodies to measles virus. Of 234 children tested (124 [53.2%] female), 133 (56.8%) had previously been vaccinated against measles virus, while 93 (39.7%) had not been vaccinated. Vaccination information for eight children could not be retrieved. One hundred and forty-three (62.4%) had measles IgM antibodies. Of these, 79 (55.3%) had been vaccinated for measles, while 65 (44.7%) had not. Despite the ongoing vaccination program in Nigeria, a high number of children are still being infected with measles, despite their vaccination status. Therefore, there is need to identify the reason for the low level of vaccine protection. PMID:26102341

  19. Infection of wild and laboratory animals with Machupo and Latino viruses*

    PubMed Central

    Webb, P. A.; Justines, G.; Johnson, K. M.

    1975-01-01

    Natural infection with Machupo and Latino viruses occurs only in the cricetine rodent Calomys callosus. Machupo virus induces fatal infection in suckling mice and hamsters, and in adult guinea-pigs, marmosets, and rhesus monkeys. Latino virus kills only suckling hamsters; it produces chronic but non-viraemic infection in Calomys rodents. Machupo virus, in contrast, induces a viraemic immunotolerant infection in suckling Calomys, and a split response in animals more than 9 days of age. Tolerant infection is associated with haemolytic anaemia and splenomegaly, lesions not observed in animals able to clear viraemia and produce circulating neutralizing antibodies. Experimental increase in the fraction of tolerant response was obtained by decreasing the virus dose or by phenotypic inbreeding of rodents. Long-term effects of tolerant infection included mild runting, decreased survival time, and almost total sterility among females, largely caused by fatal virus infection of embryos. PMID:182399

  20. Hepatitis B Virus Infection and Immunizations among Asian American College Students: Infection, Exposure, and Immunity Rates

    ERIC Educational Resources Information Center

    Lee, Haeok; Kiang, Peter; Watanabe, Paul; Halon, Patricia; Shi, Ling; Church, Daniel R.

    2013-01-01

    Objectives: To evaluate the prevalence of hepatitis B virus (HBV) infection, exposure, and immunity among Asian American college students as a basis for evaluating HBV screening and vaccination policy. Participants and Methods: Self-identified Asian American college students aged 18 years or older were examined. Serological tests of HBV surface…

  1. Experimental co-infection of chickens and turkeys with avian influenza and newcastle disease viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus (AIV) and Newcastle disease virus (NDV) are the two most important viruses affecting poultry worldwide. Co-infections of poultry with AIV and NDV are a problem from both the clinical point of view and the diagnosis of these viruses. The goal of this study was to examine the i...

  2. Oral lesions in infection with human immunodeficiency virus.

    PubMed Central

    Coogan, Maeve M.; Greenspan, John; Challacombe, Stephen J.

    2005-01-01

    This paper discusses the importance of oral lesions as indicators of infection with human immunodeficiency virus (HIV) and as predictors of progression of HIV disease to acquired immunodeficiency syndrome (AIDS). Oral manifestations are among the earliest and most important indicators of infection with HIV. Seven cardinal lesions, oral candidiasis, hairy leukoplakia, Kaposi sarcoma, linear gingival erythema, necrotizing ulcerative gingivitis, necrotizing ulcerative periodontitis and non-Hodgkin lymphoma, which are strongly associated with HIV infection, have been identified and internationally calibrated, and are seen in both developed and developing countries. They may provide a strong indication of HIV infection and be present in the majority of HIV-infected people. Antiretroviral therapy may affect the prevalence of HIV-related lesions. The presence of oral lesions can have a significant impact on health-related quality of life. Oral health is strongly associated with physical and mental health and there are significant increases in oral health needs in people with HIV infection, especially in children, and in adults particularly in relation to periodontal diseases. International collaboration is needed to ensure that oral aspects of HIV disease are taken into account in medical programmes and to integrate oral health care with the general care of the patient. It is important that all health care workers receive education and training on the relevance of oral health needs and the use of oral lesions as surrogate markers in HIV infection. PMID:16211162

  3. Hepatitis B Virus Infection during Pregnancy: Transmission and Prevention.

    PubMed

    Navabakhsh, Behrouz; Mehrabi, Narges; Estakhri, Arezoo; Mohamadnejad, Mehdi; Poustchi, Hossein

    2011-09-01

    Hepatitis B virus (HBV) infection is a global public health problem. In endemic areas, HBV infection occurs mainly during infancy and early childhood, with mother to child transmission (MTCT) accounting for approximately half of the transmission routes of chronic HBV infections. Prevention of MTCT is an essential step in reducing the global burden of chronic HBV. Natal transmission accounts for most of MTCT, and providing immunoprophylaxis to newborns is an excellent way to block natal transmission. Prenatal transmission is responsible for the minority of MTCT not preventable by immunoprophylaxis. Because of the correlation between prenatal transmission and the level of maternal viremia, some authors find it sound to offer lamivudine in women who have a high viral load (more than 8 to 9 log 10 copies/mL). In addition to considerations regarding the transmission of HBV to the child, the combination of HBV infection and pregnancy raises several unique management issues. Chronic HBV infection during pregnancy is usually mild but may flare after delivery or with discontinuing therapy. Management of chronic HBV infection in pregnancy is mostly supportive with antiviral medications indicated in a small subset of HBV infected women with rapidly progressive chronic liver disease. PMID:25197539

  4. Human Immunodeficiency Virus Infection and Host Defense in the Lungs.

    PubMed

    Charles, Tysheena P; Shellito, Judd E

    2016-04-01

    Immunosuppression associated with human immunodeficiency virus (HIV) infection impacts all components of host defense against pulmonary infection. Cells within the lung have altered immune function and are important reservoirs for HIV infection. The host immune response to infected lung cells further compromises responses to a secondary pathogenic insult. In the upper respiratory tract, mucociliary function is impaired and there are decreased levels of salivary immunoglobulin A. Host defenses in the lower respiratory tract are controlled by alveolar macrophages, lymphocytes, and polymorphonuclear leukocytes. As HIV infection progresses, lung CD4 T cells are reduced in number causing a lack of activation signals from CD4 T cells and impaired defense by macrophages. CD8 T cells, on the other hand, are increased in number and cause lymphocytic alveolitis. Specific antibody responses by B-lymphocytes are decreased and opsonization of microorganisms is impaired. These observed defects in host defense of the respiratory tract explain the susceptibility of HIV-infected persons for oropharyngeal candidiasis, bacterial pneumonia, Pneumocystis pneumonia, and other opportunistic infections. PMID:26974294

  5. Oral lesions in infection with human immunodeficiency virus.

    PubMed

    Coogan, Maeve M; Greenspan, John; Challacombe, Stephen J

    2005-09-01

    This paper discusses the importance of oral lesions as indicators of infection with human immunodeficiency virus (HIV) and as predictors of progression of HIV disease to acquired immunodeficiency syndrome (AIDS). Oral manifestations are among the earliest and most important indicators of infection with HIV. Seven cardinal lesions, oral candidiasis, hairy leukoplakia, Kaposi sarcoma, linear gingival erythema, necrotizing ulcerative gingivitis, necrotizing ulcerative periodontitis and non-Hodgkin lymphoma, which are strongly associated with HIV infection, have been identified and internationally calibrated, and are seen in both developed and developing countries. They may provide a strong indication of HIV infection and be present in the majority of HIV-infected people. Antiretroviral therapy may affect the prevalence of HIV-related lesions. The presence of oral lesions can have a significant impact on health-related quality of life. Oral health is strongly associated with physical and mental health and there are significant increases in oral health needs in people with HIV infection, especially in children, and in adults particularly in relation to periodontal diseases. International collaboration is needed to ensure that oral aspects of HIV disease are taken into account in medical programmes and to integrate oral health care with the general care of the patient. It is important that all health care workers receive education and training on the relevance of oral health needs and the use of oral lesions as surrogate markers in HIV infection. PMID:16211162

  6. Autonomic Nervous Dysfunction in Hamsters Infected with West Nile Virus

    PubMed Central

    Wang, Hong; Siddharthan, Venkatraman; Hall, Jeffery O.; Morrey, John D.

    2011-01-01

    Clinical studies and case reports clearly document that West Nile virus (WNV) can cause respiratory and gastrointestinal (GI) complications. Other functions controlled by the autonomic nervous system may also be directly affected by WNV, such as bladder and cardiac functions. To investigate how WNV can cause autonomic dysfunctions, we focused on the cardiac and GI dysfunctions of rodents infected with WNV. Infected hamsters had distension of the stomach and intestines at day 9 after viral challenge. GI motility was detected by a dye retention assay; phenol red dye was retained more in the stomachs of infected hamsters as compared to sham-infected hamsters. The amplitudes of electromygraphs (EMGs) of intestinal muscles were significantly reduced. Myenteric neurons that innervate the intestines, in addition to neurons in the brain stem, were identified to be infected with WNV. These data suggest that infected neurons controlling autonomic function were the cause of GI dysfunction in WNV-infected hamsters. Using radiotelemetry to record electrocardiograms and to measure heart rate variability (HRV), a well-accepted readout for autonomic function, we determined that HRV and autonomic function were suppressed in WNV-infected hamsters. Cardiac histopathology was observed at day 9 only in the right atrium, which was coincident with WNV staining. A subset of WNV infected cells was identified among cells with hyperplarization-activated cyclic nucleotide-gated potassium channel 4 (HCN4) as a marker for cells in the sinoatrial (SA) and atrioventricular (AV) nodes. The unique contribution of this study is the discovery that WNV infection of hamsters can lead to autonomic dysfunction as determined by reduced HRV and reduced EMG amplitudes of the GI tract. These data may model autonomic dysfunction of the human West Nile neurological disease. PMID:21573009

  7. [Hepatitis C virus infection in patients with hemophilia].

    PubMed

    Baptista González, Héctor A

    2002-10-01

    After the introduction of second generation ELISA and confirmatory tests clinically available, it was possible to determine that prevalence of infection with HCV was 98% among hemophiliacs exposed to factor VIII concentrates that weren't submitted to viral inactivation. Liver failure is 4.2 times more probable among patients also infected with HIV. The hepatocellular carcinoma studies show similar findings. They report a rate of 1.4 for every 1,000 hemophiliacs, and almost all patients have antibodies for hepatitis C virus. The studies with hemophiliacs exposed to unsafe blood products for HCV showed a significant increase in mortality from different liver diseases, as compared to control subjects. Mortality rate shows an important increase in the hemophiliacs also infected with human immunodeficiency virus. Combination therapy (ribavirin and interferon) doesn't seem to make a difference in the response rate as compared to patients without hemophilia. In spite of the best efforts to improve the safety of factor VIII concentrates, it has been impossible to eliminate the risk of transmission of other infective agents. That's why it seems that recombinant technology will be the answer in obtaining the concentrates. PMID:12712860

  8. Host Immune Status and Response to Hepatitis E Virus Infection

    PubMed Central

    Krain, Lisa J.; Nelson, Kenrad E.

    2014-01-01

    SUMMARY Hepatitis E virus (HEV), identified over 30 years ago, remains a serious threat to life, health, and productivity in developing countries where access to clean water is limited. Recognition that HEV also circulates as a zoonotic and food-borne pathogen in developed countries is more recent. Even without treatment, most cases of HEV-related acute viral hepatitis (with or without jaundice) resolve within 1 to 2 months. However, HEV sometimes leads to acute liver failure, chronic infection, or extrahepatic symptoms. The mechanisms of pathogenesis appear to be substantially immune mediated. This review covers the epidemiology of HEV infection worldwide, the humoral and cellular immune responses to HEV, and the persistence and protection of antibodies produced in response to both natural infection and vaccines. We focus on the contributions of altered immune states (associated with pregnancy, human immunodeficiency virus [HIV], and immunosuppressive agents used in cancer and transplant medicine) to the elevated risks of chronic infection (in immunosuppressed/immunocompromised patients) and acute liver failure and mortality (among pregnant women). We conclude by discussing outstanding questions about the immune response to HEV and interactions with hormones and comorbid conditions. These questions take on heightened importance now that a vaccine is available. PMID:24396140

  9. Autochthonous Dobrava-Belgrade virus infection in Eastern Germany.

    PubMed

    Rasche, Franz Maximilian; Schmidt, Sabrina; Kretzschmar, Christian; Mertens, Marc; Thiel, Jörg; Groschup, Martin H; Schlegel, Mathias; Mayer, Christof; Lindner, Tom H; Schiekofer, Stephan; Ulrich, Rainer G

    2015-02-01

    A 21-year-old male patient from Borna, Saxony, in Eastern Germany, suffered from acute kidney injury (AKI) and symptoms typical for a hantavirus infection. These symptoms included nausea, vomiting, abdominal pain, diarrhea, and acute renal failure. Serological investigations by indirect IgM and IgG in-house ELISAs, commercial immunofluorescence and line assays, as well as chemiluminescence focus reduction neutralization assay confirmed an acute Dobrava-Belgrade virus (DOBV) infection of the patient. Serological and RT-PCR analyses of striped field mouse (Apodemus agrarius) trapped in a neighboring region of the residence of the patient identified an infection by DOBV, genotype Kurkino. This is the first report of an autochthonous DOBV infection in a German patient living far from the known endemic region in the north of the country. This finding has implications for the awareness of physicians in areas which are not recognized as hantavirus endemic regions but where the reservoir host of the virus is present. PMID:24495905

  10. Reevaluation of possible outcomes of infections with human immunodeficiency virus.

    PubMed

    Tamalet, C; Colson, P; Decroly, E; Dhiver, C; Ravaux, I; Stein, A; Raoult, D

    2016-04-01

    Several lines of evidence indicate that HIV infection can result in several possible incomes, including a very small proportion of individuals whose HIV replication is controlled after treatment interruption (known as HIV posttreatment controllers) or spontaneously without any treatment (known as HIV elite controllers). Both types of individuals are HIV RNA negative but HIV DNA positive, with living virus which can be stimulated ex vivo. A review was conducted to assess the literature on yet rarer cases with detectable integrated HIV DNA without HIV infectious virus in HIV-seropositive or -negative individuals. Three categories of patients were identified: (a) HIV-seropositive individuals with apparent spontaneous cure from their HIV infection, (b) HIV-seronegative children born to HIV-infected mothers and (c) highly exposed seronegative adults. Validity criteria were proposed to assess the presence of integrated HIV DNA as possible or unquestionable in these three categories. Only three articles among the 22 ultimately selected fulfilled these criteria. Among the highly exposed seronegative subjects, some individuals were described as being without integrated HIV DNA, probably because these subjects were not investigated using relevant, highly sensitive methods. Finally, we propose a definition of spontaneous cure of HIV infection based on clinical, immunologic and virologic criteria. PMID:26794031

  11. Hepatitis C virus infection of cholangiocarcinoma cell lines.

    PubMed

    Fletcher, Nicola F; Humphreys, Elizabeth; Jennings, Elliott; Osburn, William; Lissauer, Samantha; Wilson, Garrick K; van IJzendoorn, Sven C D; Baumert, Thomas F; Balfe, Peter; Afford, Simon; McKeating, Jane A

    2015-06-01

    Hepatitis C virus (HCV) infects the liver and hepatocytes are the major cell type supporting viral replication. Hepatocytes and cholangiocytes derive from a common hepatic progenitor cell that proliferates during inflammatory conditions, raising the possibility that cholangiocytes may support HCV replication and contribute to the hepatic reservoir. We screened cholangiocytes along with a panel of cholangiocarcinoma-derived cell lines for their ability to support HCV entry and replication. While primary cholangiocytes were refractory to infection and lacked expression of several entry factors, two cholangiocarcinoma lines, CC-LP-1 and Sk-ChA-1, supported efficient HCV entry; furthermore, Sk-ChA-1 cells supported full virus replication. In vivo cholangiocarcinomas expressed all of the essential HCV entry factors; however, cholangiocytes adjacent to the tumour and in normal tissue showed a similar pattern of receptor expression to ex vivo isolated cholangiocytes, lacking SR-BI expression, explaining their inability to support infection. This study provides the first report that HCV can infect cholangiocarcinoma cells and suggests that these heterogeneous tumours may provide a reservoir for HCV replication in vivo. PMID:25701818

  12. Hepatitis C virus infection of cholangiocarcinoma cell lines

    PubMed Central

    Fletcher, Nicola F.; Humphreys, Elizabeth; Jennings, Elliott; Osburn, William; Lissauer, Samantha; Wilson, Garrick K.; van IJzendoorn, Sven C. D.; Baumert, Thomas F.; Balfe, Peter; Afford, Simon

    2015-01-01

    Hepatitis C virus (HCV) infects the liver and hepatocytes are the major cell type supporting viral replication. Hepatocytes and cholangiocytes derive from a common hepatic progenitor cell that proliferates during inflammatory conditions, raising the possibility that cholangiocytes may support HCV replication and contribute to the hepatic reservoir. We screened cholangiocytes along with a panel of cholangiocarcinoma-derived cell lines for their ability to support HCV entry and replication. While primary cholangiocytes were refractory to infection and lacked expression of several entry factors, two cholangiocarcinoma lines, CC-LP-1 and Sk-ChA-1, supported efficient HCV entry; furthermore, Sk-ChA-1 cells supported full virus replication. In vivo cholangiocarcinomas expressed all of the essential HCV entry factors; however, cholangiocytes adjacent to the tumour and in normal tissue showed a similar pattern of receptor expression to ex vivo isolated cholangiocytes, lacking SR-BI expression, explaining their inability to support infection. This study provides the first report that HCV can infect cholangiocarcinoma cells and suggests that these heterogeneous tumours may provide a reservoir for HCV replication in vivo. PMID:25701818

  13. Porcine epidemic diarrhea virus infection: Etiology, epidemiology, pathogenesis and immunoprophylaxis.

    PubMed

    Jung, Kwonil; Saif, Linda J

    2015-05-01

    Porcine epidemic diarrhea virus (PEDV), a member of the genera Alphacoronavirus in the family Coronaviridae, causes acute diarrhea/vomiting, dehydration and high mortality in seronegative neonatal piglets. For the last three decades, PEDV infection has resulted in significant economic losses in the European and Asian pig industries, but in 2013-2014 the disease was also reported in the US, Canada and Mexico. The PED epidemic in the US, from April 2013 to the present, has led to the loss of more than 10% of the US pig population. The disappearance and re-emergence of epidemic PED indicates that the virus is able to escape from current vaccination protocols, biosecurity and control systems. Endemic PED is a significant problem, which is exacerbated by the emergence (or potential importation) of multiple PEDV variants. Epidemic PEDV strains spread rapidly and cause a high number of pig deaths. These strains are highly enteropathogenic and acutely infect villous epithelial cells of the entire small and large intestines although the jejunum and ileum are the primary sites. PEDV infections cause acute, severe atrophic enteritis accompanied by viremia that leads to profound diarrhea and vomiting, followed by extensive dehydration, which is the major cause of death in nursing piglets. A comprehensive understanding of the pathogenic characteristics of epidemic or endemic PEDV strains is needed to prevent and control the disease in affected regions and to develop an effective vaccine. This review focuses on the etiology, epidemiology, disease mechanisms and pathogenesis as well as immunoprophylaxis against PEDV infection. PMID:25841898

  14. HIV Infection Upregulates Caveolin 1 Expression To Restrict Virus Production▿

    PubMed Central

    Lin, Shanshan; Wang, Xiao Mei; Nadeau, Peter E.; Mergia, Ayalew

    2010-01-01

    Caveolin 1 (Cav-1) is a major protein of a specific membrane lipid raft known as caveolae. Cav-1 interacts with the gp41 of the human immunodeficiency virus (HIV) envelope, but the role of Cav-1 in HIV replication and pathogenesis is not known. In this report, we demonstrate that HIV infection in primary human monocyte-derived macrophages (MDMs), THP-1 macrophages, and U87-CD4 cells results in a dramatic upregulation of Cav-1 expression mediated by HIV Tat. The activity of p53 is essential for Tat-induced Cav-1 expression, as our findings show enhanced phosphorylation of serine residues at amino acid positions 15 and 46 in the presence of Tat with a resulting Cav-1 upregulation. Furthermore, inhibition of p38 mitogen-activated protein kinase (MAPK) blocked phosphorylation of p53 in the presence of Tat. Infection studies of Cav-1-overexpressing cells reveal a significant reduction of HIV production. Taken together, these results suggest that HIV infection enhances the expression of Cav-1, which subsequently causes virus reduction, suggesting that Cav-1 may contribute to persistent infection in macrophages. PMID:20610713

  15. Plasmacytoid Dendritic Cell Infection and Sensing Capacity during Pathogenic and Nonpathogenic Simian Immunodeficiency Virus Infection

    PubMed Central

    Jochems, Simon P.; Jacquelin, Beatrice; Chauveau, Lise; Huot, Nicolas; Petitjean, Gaël; Lepelley, Alice; Liovat, Anne-Sophie; Ploquin, Mickaël J.; Cartwright, Emily K.; Bosinger, Steven E.; Silvestri, Guido; Barré-Sinoussi, Françoise; Lebon, Pierre; Schwartz, Olivier

    2015-01-01

    ABSTRACT Human immunodeficiency virus (HIV) in humans and simian immunodeficiency virus (SIV) in macaques (MAC) lead to chronic inflammation and AIDS. Natural hosts, such as African green monkeys (AGM) and sooty mangabeys (SM), are protected against SIV-induced chronic inflammation and AIDS. Here, we report that AGM plasmacytoid dendritic cells (pDC) express extremely low levels of CD4, unlike MAC and human pDC. Despite this, AGM pDC efficiently sensed SIVagm, but not heterologous HIV/SIV isolates, indicating a virus-host adaptation. Moreover, both AGM and SM pDC were found to be, in contrast to MAC pDC, predominantly negative for CCR5. Despite such limited CD4 and CCR5 expression, lymphoid tissue pDC were infected to a degree similar to that seen with CD4+ T cells in both MAC and AGM. Altogether, our finding of efficient pDC infection by SIV in vivo identifies pDC as a potential viral reservoir in lymphoid tissues. We discovered low expression of CD4 on AGM pDC, which did not preclude efficient sensing of host-adapted viruses. Therefore, pDC infection and efficient sensing are not prerequisites for chronic inflammation. The high level of pDC infection by SIVagm suggests that if CCR5 paucity on immune cells is important for nonpathogenesis of natural hosts, it is possibly not due to its role as a coreceptor. IMPORTANCE The ability of certain key immune cell subsets to resist infection might contribute to the asymptomatic nature of simian immunodeficiency virus (SIV) infection in its natural hosts, such as African green monkeys (AGM) and sooty mangabeys (SM). This relative resistance to infection has been correlated with reduced expression of CD4 and/or CCR5. We show that plasmacytoid dendritic cells (pDC) of natural hosts display reduced CD4 and/or CCR5 expression, unlike macaque pDC. Surprisingly, this did not protect AGM pDC, as infection levels were similar to those found in MAC pDC. Furthermore, we show that AGM pDC did not consistently produce type I

  16. Dynamics of virus shedding and antibody responses in influenza A virus-infected feral swine.

    PubMed

    Sun, Hailiang; Cunningham, Fred L; Harris, Jillian; Xu, Yifei; Long, Li-Ping; Hanson-Dorr, Katie; Baroch, John A; Fioranelli, Paul; Lutman, Mark W; Li, Tao; Pedersen, Kerri; Schmit, Brandon S; Cooley, Jim; Lin, Xiaoxu; Jarman, Richard G; DeLiberto, Thomas J; Wan, Xiu-Feng

    2015-09-01

    Given their free-ranging habits, feral swine could serve as reservoirs or spatially dynamic 'mixing vessels' for influenza A virus (IAV). To better understand virus shedding patterns and antibody response dynamics in the context of IAV surveillance amongst feral swine, we used IAV of feral swine origin to perform infection experiments. The virus was highly infectious and transmissible in feral swine, and virus shedding patterns and antibody response dynamics were similar to those in domestic swine. In the virus-inoculated and sentinel groups, virus shedding lasted ≤ 6 and ≤ 9 days, respectively. Antibody titres in inoculated swine peaked at 1 : 840 on day 11 post-inoculation (p.i.), remained there until 21 days p.i. and dropped to < 1 : 220 at 42 days p.i. Genomic sequencing identified changes in wildtype (WT) viruses and isolates from sentinel swine, most notably an amino acid divergence in nucleoprotein position 473. Using data from cell culture as a benchmark, sensitivity and specificity of a matrix gene-based quantitative reverse transcription-PCR method using nasal swab samples for detection of IAV in feral swine were 78.9 and 78.1 %, respectively. Using data from haemagglutination inhibition assays as a benchmark, sensitivity and specificity of an ELISA for detection of IAV-specific antibody were 95.4 and 95.0 %, respectively. Serological surveillance from 2009 to 2014 showed that ∼7.58 % of feral swine in the USA were positive for IAV. Our findings confirm the susceptibility of IAV infection and the high transmission ability of IAV amongst feral swine, and also suggest the need for continued surveillance of IAVs in feral swine populations. PMID:26297148

  17. Infection of Murine Macrophages by Salmonella enterica Serovar Heidelberg Blocks Murine Norovirus Infectivity and Virus-induced Apoptosis.

    PubMed

    Agnihothram, Sudhakar S; Basco, Maria D S; Mullis, Lisa; Foley, Steven L; Hart, Mark E; Sung, Kidon; Azevedo, Marli P

    2015-01-01

    Gastroenteritis caused by bacterial and viral pathogens constitutes a major public health threat in the United States accounting for 35% of hospitalizations. In particular, Salmonella enterica and noroviruses cause the majority of gastroenteritis infections, with emergence of sporadic outbreaks and incidence of increased infections. Although mechanisms underlying infections by these pathogens have been individually studied, little is known about the mechanisms regulating co-infection by these pathogens. In this study, we utilized RAW 264.7 murine macrophage cells to investigate the mechanisms governing co-infection with S. enterica serovar Heidelberg and murine norovirus (MNV). We demonstrate that infection of RAW 264.7 cells with S. enterica reduces the replication of MNV, in part by blocking virus entry early in the virus life cycle, and inducing antiviral cytokines later in the infection cycle. In particular, bacterial infection prior to, or during MNV infection affected virus entry, whereas MNV entry remained unaltered when the virus infection preceded bacterial invasion. This block in virus entry resulted in reduced virus replication, with the highest impact on replication observed during conditions of co-infection. In contrast, bacterial replication showed a threefold increase in MNV-infected cells, despite the presence of antibiotic in the medium. Most importantly, we present evidence that the infection of MNV-infected macrophages by S. enterica blocked MNV-induced apoptosis, despite allowing efficient virus replication. This apoptosis blockade was evidenced by reduction in DNA fragmentation and absence of poly-ADP ribose polymerase (PARP), caspase 3 and caspase 9 cleavage events. Our study suggests a novel mechanism of pathogenesis whereby initial co-infection with these pathogens could result in prolonged infection by either of these pathogens or both together. PMID:26658916

  18. Infection of Murine Macrophages by Salmonella enterica Serovar Heidelberg Blocks Murine Norovirus Infectivity and Virus-induced Apoptosis

    PubMed Central

    Agnihothram, Sudhakar S.; Basco, Maria D. S.; Mullis, Lisa; Foley, Steven L.; Hart, Mark E.; Sung, Kidon; Azevedo, Marli P.

    2015-01-01

    Gastroenteritis caused by bacterial and viral pathogens constitutes a major public health threat in the United States accounting for 35% of hospitalizations. In particular, Salmonella enterica and noroviruses cause the majority of gastroenteritis infections, with emergence of sporadic outbreaks and incidence of increased infections. Although mechanisms underlying infections by these pathogens have been individually studied, little is known about the mechanisms regulating co-infection by these pathogens. In this study, we utilized RAW 264.7 murine macrophage cells to investigate the mechanisms governing co-infection with S. enterica serovar Heidelberg and murine norovirus (MNV). We demonstrate that infection of RAW 264.7 cells with S. enterica reduces the replication of MNV, in part by blocking virus entry early in the virus life cycle, and inducing antiviral cytokines later in the infection cycle. In particular, bacterial infection prior to, or during MNV infection affected virus entry, whereas MNV entry remained unaltered when the virus infection preceded bacterial invasion. This block in virus entry resulted in reduced virus replication, with the highest impact on replication observed during conditions of co-infection. In contrast, bacterial replication showed a threefold increase in MNV-infected cells, despite the presence of antibiotic in the medium. Most importantly, we present evidence that the infection of MNV-infected macrophages by S. enterica blocked MNV-induced apoptosis, despite allowing efficient virus replication. This apoptosis blockade was evidenced by reduction in DNA fragmentation and absence of poly-ADP ribose polymerase (PARP), caspase 3 and caspase 9 cleavage events. Our study suggests a novel mechanism of pathogenesis whereby initial co-infection with these pathogens could result in prolonged infection by either of these pathogens or both together. PMID:26658916

  19. Clinical aspects on Epstein-Barr virus infection.

    PubMed

    Andersson, J P

    1991-01-01

    Epstein-Barr virus infection (EBV) was discovered 25 years ago in tumour cells from Burkitt's lymphoma. Extensive virological studies have relieved that EBV causes infectious mononucleosis and contributes to the pathogenesis of Burkitt's lymphoma and nasopharyngeal cancer. Atypical courses of the primary infection may induce meningoencephalitis or hepatitis and are attracting increasing attention. Antiviral treatment with acyclovir has been administered for 7 days, intravenously or orally, in the early stages of infectious mononucleosis, in 2 placebo controlled trials. An inhibition of oropharyngeal EBV replication was verified but minimal effects on clinical symptoms was observed. A combination of intravenous acyclovir and prednisolone treatment for 10 days was therefore tried in 15 patients with fulminant mononucleosis in a pilot study. A transient cessation of virus shedding was noticed in all patients, and a substantial clinical effect on pharyngeal symptoms and on fever was seen in 12/15 patients within 3 days. Treatment with chemotherapy or irradiation is recommended in EBV-associated B-cell lymphomas seen in immunosuppressed, transplanted, or human immunodeficiency virus-seropositive patients. No effect of acyclovir has been reported, but such therapy may be considered in the early stage when EBV induces a polyclonal B cell activation. Acyclovir treatment is effective in the EBV-genome positive hairy leukoplakia noticed in human immunodeficiency virus-seropositive patients. However, no effect of any antiviral therapy has been reported in the X-linked lymphoproliferative syndrome affecting in particular 2-7 year old boys. Prophylactic use of immunoglobulin or acyclovir has been suggested in susceptible children. These results indicate that the variety of clinical manifestations induced by EBV at least partly depend on the immune response elicited in the host and not of virus replication per se. Therefore, treatment of these various disorders cannot be

  20. High doses of highly pathogenic avian influenza virus in chicken meat are required to infect ferrets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    H5N1 high pathogenicity avian influenza viruses (HPAIV) have caused natural and experimental infections in various animals through consumption of infected bird carcasses and meat. However, little is known about the quantity of virus required and if all HPAIV subtypes can cause infections following c...