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Sample records for giant viruses infecting

  1. Giant viruses infecting algae.

    PubMed

    Van Etten, J L; Meints, R H

    1999-01-01

    Paramecium bursaria chlorella virus (PBCV-1) is the prototype of a family of large, icosahedral, plaque-forming, double-stranded-DNA-containing viruses that replicate in certain unicellular, eukaryotic chlorella-like green algae. DNA sequence analysis of its 330, 742-bp genome leads to the prediction that this phycodnavirus has 376 protein-encoding genes and 10 transfer RNA genes. The predicted gene products of approximately 40% of these genes resemble proteins of known function. The chlorella viruses have other features that distinguish them from most viruses, in addition to their large genome size. These features include the following: (a) The viruses encode multiple DNA methyltransferases and DNA site-specific endonucleases; (b) PBCV-1 encodes at least part, if not the entire machinery to glycosylate its proteins; (c) PBCV-1 has at least two types of introns--a self-splicing intron in a transcription factor-like gene and a splicesomal processed type of intron in its DNA polymerase gene. Unlike the chlorella viruses, large double-stranded-DNA-containing viruses that infect marine, filamentous brown algae have a circular genome and a lysogenic phase in their life cycle. PMID:10547698

  2. 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

  3. 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 with herpes virus infection; yet, they can also be observed in patients with skin tumors or acantholytic dermatoses. Cutaneous herpes simplex virus infection can coexist in association with other conditions such as acantholytic dermatoses, benign skin tumors, bullous disorders, hematologic malignancies, inflammatory dermatoses, and physical therapies. However, when a herpes virus infection is suspected based upon the discovery of epithelial multinucleated giant cells in the epidermis, but either the clinic presentation or lack of response to viral therapy or absence of confirmatory laboratory studies does not support the diagnosis of a viral infection, the possibility of a primary acantholytic dermatosis should be considered and additional lesional skin biopsies performed. Also, because hematoxylin and eosin staining is not the golden standard for confirmation of autoimmune bullous dermatoses, skin biopsies for direct immunofluorescence should be performed when a primary bullous dermatosis is suspected since the histopathology observed on hematoxylin and eosin stained sections can be misleading. PMID:25396080

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

    PubMed Central

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

    2014-01-01

    Nucleocytoplasmic large DNA viruses (NCLDVs) are eukaryotic viruses with large genomes (100?kb2.5?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

  5. 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

  6. 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-2?, 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

  7. Faustovirus, an Asfarvirus-Related New Lineage of Giant Viruses Infecting Amoebae

    PubMed Central

    Reteno, Dorine Gaëlle; Benamar, Samia; Khalil, Jacques Bou; Andreani, Julien; Armstrong, Nicholas; Klose, Thomas; Rossmann, Michael; Colson, Philippe; Raoult, Didier

    2015-01-01

    ABSTRACT Giant viruses are protist-associated viruses belonging to the proposed order Megavirales; almost all have been isolated from Acanthamoeba spp. Their isolation in humans suggests that they are part of the human virome. Using a high-throughput strategy to isolate new giant viruses from their original protozoan hosts, we obtained eight isolates of a new giant viral lineage from Vermamoeba vermiformis, the most common free-living protist found in human environments. This new lineage was proposed to be the faustovirus lineage. The prototype member, faustovirus E12, forms icosahedral virions of ≈200 nm that are devoid of fibrils and that encapsidate a 466-kbp genome encoding 451 predicted proteins. Of these, 164 are found in the virion. Phylogenetic analysis of the core viral genes showed that faustovirus is distantly related to the mammalian pathogen African swine fever virus, but it encodes ≈3 times more mosaic gene complements. About two-thirds of these genes do not show significant similarity to genes encoding any known proteins. These findings show that expanding the panel of protists to discover new giant viruses is a fruitful strategy. IMPORTANCE By using Vermamoeba, a protist living in humans and their environment, we isolated eight strains of a new giant virus that we named faustovirus. The genomes of these strains were sequenced, and their sequences showed that faustoviruses are related to but different from the vertebrate pathogen African swine fever virus (ASFV), which belongs to the family Asfarviridae. Moreover, the faustovirus gene repertoire is ≈3 times larger than that of ASFV and comprises approximately two-thirds ORFans (open reading frames [ORFs] with no detectable homology to other ORFs in a database). PMID:25878099

  8. 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

  9. 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

  10. Giant virus in the sea

    PubMed Central

    Claverie, Jean-Michel

    2013-01-01

    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

  11. Evolutionary dynamics of giant viruses and their virophages

    PubMed Central

    Wodarz, Dominik

    2013-01-01

    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

  12. 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

  13. 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.

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

    PubMed

    Desnues, Christelle; La Scola, Bernard; Yutin, Natalya; Fournous, Ghislain; Robert, Catherine; Azza, Sad; Jardot, Priscilla; Monteil, Sonia; Campocasso, Anglique; 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

  15. Giant cell encephalitis and microglial infection with mucosally transmitted simian-human immunodeficiency virus SHIVSF162P3N in rhesus macaques

    PubMed Central

    Harbison, Carole; Zhuang, Ke; Gettie, Agegnehu; Blanchard, James; Knight, Heather; Didier, Peter; Cheng-Mayer, Cecilia; Westmoreland, Susan

    2015-01-01

    Neurocognitive disorders such as dementia and cognitive/motor impairments are among the most significant complications associated with human immunodeficiency virus (HIV) infection, especially in aging populations, yet the pathogenesis remains poorly understood. Activated macrophages and microglia in white matter along with the hallmark multinucleated giant cells are prominent features of HIV encephalitis (HIVE) and of several simian immunodeficiency virus (SIV) models. While infected microglia have been demonstrated in HIVE, this feature is not routinely seen in experimental infections in rhesus macaques using SIV or chimeric simian/HIV (SHIV) strains, limiting utility in HIV-1 pathogenesis and treatment studies. Here, 50 rhesus macaques were inoculated with the CCR5 (R5)-tropic SHIVSF162P3N virus by one of three routes: intravenously (n=9), intrarectally (n=17), or intravaginally (n=24). Forty-three monkeys became viremic, 26 developed AIDS, and 7 (7/26, 27 %) developed giant cell SIVencephalitis (SIVE). Rapid progressor phenotype was evident in five of seven (71 %) macaques with SIVE, and expansion to utilize the CXCR4 coreceptor (X4 coreceptor switch) was observed in four out of seven (57 %). SIVE lesions were present in gray and white matter in the cerebrum, cerebellum, thalamus, and brain stem of affected animals. Lesions were composed of virally infected CD68+, CD163+, and HLA-DR+ macrophages accompanied by white matter damage, necrosis, and astroglial and microglial activation. Importantly, microglial infection was observed, which makes R5 SHIVSF162P3N infection of macaques an attractive animal model not only to study transmission and HIVE pathogenesis but also to conduct preclinical evaluation of therapeutic interventions aimed at eradicating HIV-1 from the central nervous system (CNS). PMID:24464410

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

    PubMed

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

    2014-10-01

    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 500kb, namely Mimiviruses, Pithoviruses, and Pandoraviruses that hold the current record of viral genome size, about 2.5Mb. 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

  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. A case of liver cirrhosis due to hepatits C virus infection complicating giant anorectal varices treated with balloon-occluded retrograde transvenous obliteration.

    PubMed

    Watanabe, Kazuhiro; Imai, Yukinori; Takaya, Hiroaki; Nakazawa, Manabu; Chikayama, Taku; Ando, Satsuki; Mizuno, Yoshie; Sugawara, Kayoko; Nakamura, Yuuka; Saitoh, Eiko; Hamaoka, Kazuhiro; Motoya, Daisuke; Fujimori, Kenji; Inao, Mie; Nakayama, Nobuaki; Nagoshi, Sumiko; Mochida, Satoshi

    2011-02-01

    A 73-year-old man with liver cirrhosis due to hepatitis C virus infection was admitted to our hospital because of massive bleeding from external varices. Colonoscopic examination revealed that giant anorectal varices had developed between the anus and rectal ampulla, and had ruptured at the perianal site. On three-dimensional computed tomography imaging, the feeding and drainage vessels of the varices were identified as the inferior mesenteric vein and right inferior hemorrhoidal vein, respectively. Endoscopic therapies were not employed for the bleeding varices, because the blood flow volume of the feeding vessel was extremely large. Balloon-occluded retrograde transvenous obliteration (B-RTO) was therefore carried out through the drainage vessels. The variceal blood flow disappeared after B-RTO therapy, and the varices decreased in size with thrombus formation verified by colonoscopy. Bleeding from the external varices also ceased. B-RTO therapy may be an effective approach for giant anorectal varices presenting as a complication in liver cirrhosis patients in whom the main drainage vessels can be determined. PMID:26190616

  19. The Giant Cafeteria roenbergensis Virus That Infects a Widespread Marine Phagocytic Protist Is a New Member of the Fourth Domain of Life

    PubMed Central

    Colson, Philippe; Gimenez, Gregory; Boyer, Mickal; Fournous, Ghislain; Raoult, Didier

    2011-01-01

    Background A recent work has provided strong arguments in favor of a fourth domain of Life composed of nucleo-cytoplasmic large DNA viruses (NCLDVs). This hypothesis was supported by phylogenetic and phyletic analyses based on a common set of proteins conserved in Eukarya, Archaea, Bacteria, and viruses, and implicated in the functions of information storage and processing. Recently, the genome of a new NCLDV, Cafeteria roenbergensis virus (CroV), was released. The present work aimed to determine if CroV supports the fourth domain of Life hypothesis. Methods A consensus phylogenetic tree of NCLDVs including CroV was generated from a concatenated alignment of four universal proteins of NCLDVs. Some features of the gene complement of CroV and its distribution along the genome were further analyzed. Phylogenetic and phyletic analyses were performed using the previously identified common set of informational genes present in Eukarya, Archaea, Bacteria, and NCLDVs, including CroV. Findings Phylogenetic reconstructions indicated that CroV is clearly related to the Mimiviridae family. The comparison between the gene repertoires of CroV and Mimivirus showed similarities regarding the gene contents and genome organization. In addition, the phyletic clustering based on the comparison of informational gene repertoire between Eukarya, Archaea, Bacteria, and NCLDVs unambiguously classified CroV with other NCLDVs and clearly included it in a fourth domain of Life. Taken together, these data suggest that Mimiviridae, including CroV, may have inherited a common gene content probably acquired from a common Mimiviridae ancestor. Conclusions This further analysis of the gene repertoire of CroV consolidated the fourth domain of Life hypothesis and contributed to outline a functional pan-genome for giant viruses infecting phagocytic protistan grazers. PMID:21559486

  20. 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

  1. Zika Virus Infection

    MedlinePLUS

    ... Rare Diseases Information Center (GARD) Print friendly version Zika virus infection Table of Contents Overview Tests & Diagnosis Treatment ... Answered Other Names for this Disease Zika fever Zika virus disease About the GARD Information Center See Disclaimer ...

  2. 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

  3. 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

  4. Hepatitis B virus infection.

    PubMed

    Trpo, Christian; Chan, Henry L Y; Lok, Anna

    2014-12-01

    Hepatitis B virus infection is a major public health problem worldwide; roughly 30% of the world's population show serological evidence of current or past infection. Hepatitis B virus is a partly double-stranded DNA virus with several serological markers: HBsAg and anti-HBs, HBeAg and anti-HBe, and anti-HBc IgM and IgG. It is transmitted through contact with infected blood and semen. A safe and effective vaccine has been available since 1981, and, although variable, the implementation of universal vaccination in infants has resulted in a sharp decline in prevalence. Hepatitis B virus is not cytopathic; both liver damage and viral control--and therefore clinical outcome--depend on the complex interplay between virus replication and host immune response. Overall, as much as 40% of men and 15% of women with perinatally acquired hepatitis B virus infection will die of liver cirrhosis or hepatocellular carcinoma. In addition to decreasing hepatic inflammation, long-term antiviral treatment can reverse cirrhosis and reduce hepatocellular carcinoma. Development of new therapies that can improve HBsAg clearance and virological cure is warranted. PMID:24954675

  5. [West Nile virus infection].

    PubMed

    Prez Ruiz, Mercedes; Gmez, Sara Sanbonmatsu; Clavero, Miguel Angel Jimnez

    2011-12-01

    West Nile virus (WNV) is an arbovirus usually transmitted by mosquitoes. The main reservoirs are birds, although the virus may infect several vertebrate species, such as horses and humans. Up to 80% of human infections are asymptomatic. The most frequent clinical presentation is febrile illness, and neuroinvasive disease can occur in less than 1% of cases. Spain is considered a high-risk area for the emergence of WNV due to its climate and the passage of migratory birds from Africa (where the virus is endemic). These birds nest surrounding wetlands where populations of possible vectors for the virus are abundant. Diagnosis of human neurological infections can be made by detection of IgM in serum and/or cerebrospinal fluid samples, demonstration of a four-fold increase in IgG antibodies between acute-phase and convalescent-phase serum samples, or by detection of viral genome by reverse transcription-polymerase chain reaction (especially useful in transplant recipients). Since WNV is a biosafety level 3 agent, techniques that involve cell culture are restricted to laboratories with this level of biosafety, such as reference laboratories. The National Program for the Surveillance of WNV Encephalitis allows the detection of virus circulation among birds and vectors in areas especially favorable for the virus, such as wetlands, and provides information for evaluation of the risk of disease in horses and humans. PMID:22305666

  6. 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

  7. 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

  8. 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

  9. Virus infection improves drought tolerance.

    PubMed

    Xu, Ping; Chen, Fang; Mannas, Jonathan P; Feldman, Tracy; Sumner, Lloyd W; Roossinck, Marilyn J

    2008-01-01

    Viruses are obligate intracellular symbionts. Plant viruses are often discovered and studied as pathogenic parasites that cause diseases in agricultural plants. However, here it is shown that viruses can extend survival of their hosts under conditions of abiotic stress that could benefit hosts if they subsequently recover and reproduce. Various plant species were inoculated with four different RNA viruses, Brome mosaic virus (BMV), Cucumber mosaic virus (CMV), Tobacco mosaic virus and Tobacco rattle virus. The inoculated plants were stressed by withholding water. The onset of drought symptoms in virus-infected plants was compared with that in the plants that were inoculated with buffer (mock-inoculated plants). Metabolite profiling analysis was conducted and compared between mock-inoculated and virus-infected plants before and after being subjected to drought stress. In all cases, virus infection delayed the appearance of drought symptoms. Beet plants infected with CMV also exhibited significantly improved tolerance to freezing. Metabolite profiling analysis showed an increase in several osmoprotectants and antioxidants in BMV-infected rice and CMV-infected beet plants before and after drought stress. These results indicate that virus infection improves plant tolerance to abiotic stress, which correlates with increased osmoprotectant and antioxidant levels in infected plants. PMID:18823313

  10. 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

  11. Avian Influenza A Virus Infections in Humans

    MedlinePLUS

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  12. 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

  13. Mimivirus and the emerging concept of "giant" virus.

    PubMed

    Claverie, Jean-Michel; Ogata, Hiroyuki; Audic, Stphane; Abergel, Chantal; Suhre, Karsten; Fournier, Pierre-Edouard

    2006-04-01

    The recently discovered Acanthamoeba polyphaga Mimivirus is the largest known DNA virus. Its particle size (750 nm), genome length (1.2 million bp) and large gene repertoire (911 protein coding genes) blur the established boundaries between viruses and parasitic cellular organisms. In addition, the analysis of its genome sequence identified many types of genes never before encountered in a virus, including aminoacyl-tRNA synthetases and other central components of the translation machinery previously thought to be the signature of cellular organisms. In this article, we examine how the finding of such a giant virus might durably influence the way we look at microbial biodiversity, and lead us to revise the classification of microbial domains and life forms. We propose to introduce the word "girus" to recognize the intermediate status of these giant DNA viruses, the genome complexity of which makes them closer to small parasitic prokaryotes than to regular viruses. PMID:16469402

  14. 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

  15. Membrane assembly during the infection cycle of the giant Mimivirus.

    PubMed

    Mutsafi, Yael; Shimoni, Eyal; Shimon, Amir; Minsky, Abraham

    2013-01-01

    Although extensively studied, the structure, cellular origin and assembly mechanism of internal membranes during viral infection remain unclear. By combining diverse imaging techniques, including the novel Scanning-Transmission Electron Microscopy tomography, we elucidate the structural stages of membrane biogenesis during the assembly of the giant DNA virus Mimivirus. We show that this elaborate multistage process occurs at a well-defined zone localized at the periphery of large viral factories that are generated in the host cytoplasm. Membrane biogenesis is initiated by fusion of multiple vesicles, ~70 nm in diameter, that apparently derive from the host ER network and enable continuous supply of lipid components to the membrane-assembly zone. The resulting multivesicular bodies subsequently rupture to form large open single-layered membrane sheets from which viral membranes are generated. Membrane generation is accompanied by the assembly of icosahedral viral capsids in a process involving the hypothetical major capsid protein L425 that acts as a scaffolding protein. The assembly model proposed here reveals how multiple Mimivirus progeny can be continuously and efficiently generated and underscores the similarity between the infection cycles of Mimivirus and Vaccinia virus. Moreover, the membrane biogenesis process indicated by our findings provides new insights into the pathways that might mediate assembly of internal viral membranes in general. PMID:23737745

  16. Membrane Assembly during the Infection Cycle of the Giant Mimivirus

    PubMed Central

    Mutsafi, Yael; Shimoni, Eyal; Shimon, Amir; Minsky, Abraham

    2013-01-01

    Although extensively studied, the structure, cellular origin and assembly mechanism of internal membranes during viral infection remain unclear. By combining diverse imaging techniques, including the novel Scanning-Transmission Electron Microscopy tomography, we elucidate the structural stages of membrane biogenesis during the assembly of the giant DNA virus Mimivirus. We show that this elaborate multistage process occurs at a well-defined zone localized at the periphery of large viral factories that are generated in the host cytoplasm. Membrane biogenesis is initiated by fusion of multiple vesicles, ?70 nm in diameter, that apparently derive from the host ER network and enable continuous supply of lipid components to the membrane-assembly zone. The resulting multivesicular bodies subsequently rupture to form large open single-layered membrane sheets from which viral membranes are generated. Membrane generation is accompanied by the assembly of icosahedral viral capsids in a process involving the hypothetical major capsid protein L425 that acts as a scaffolding protein. The assembly model proposed here reveals how multiple Mimivirus progeny can be continuously and efficiently generated and underscores the similarity between the infection cycles of Mimivirus and Vaccinia virus. Moreover, the membrane biogenesis process indicated by our findings provides new insights into the pathways that might mediate assembly of internal viral membranes in general. PMID:23737745

  17. 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 ( ...

  18. 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 ...

  19. Chikungunya virus infection.

    PubMed

    Simon, Fabrice; Javelle, Emilie; Oliver, Manuela; Leparc-Goffart, Isabelle; Marimoutou, Catherine

    2011-06-01

    Chikungunya virus (CHIKV) is an alphavirus transmitted by mosquitoes, mostly Aedes aegypti and Aedes albopictus. After half a century of focal outbreaks of acute febrile polyarthralgia in Africa and Asia, the disease unexpectedly spread in the past decade with large outbreaks in Africa and around the Indian Ocean and rare autochthonous transmission in temperate areas. This emergence brought new insights on its pathogenesis, notably the role of the A226V mutation that improved CHIKV fitness in Ae. albopictus and the possible CHIKV persistence in deep tissue sanctuaries for months after infection. Massive outbreaks also revealed new aspects of the acute stage: the high number of symptomatic cases, unexpected complications, mother-to-child transmission, and low lethality in debilitated patients. The follow-up of patients in epidemic areas has identified frequent, long-lasting, rheumatic disorders, including rare inflammatory joint destruction, and common chronic mood changes associated with quality-of-life impairment. Thus, the globalization of CHIKV exposes countries with Aedes mosquitoes both to brutal outbreaks of acute incapacitating episodes and endemic long-lasting disorders. PMID:21465340

  20. Translation in Giant Viruses: A Unique Mixture of Bacterial and Eukaryotic Termination Schemes

    PubMed Central

    Jeudy, Sandra; Abergel, Chantal; Claverie, Jean-Michel; Legendre, Matthieu

    2012-01-01

    Mimivirus and Megavirus are the best characterized representatives of an expanding new family of giant viruses infecting Acanthamoeba. Their most distinctive features, megabase-sized genomes carried in particles of size comparable to that of small bacteria, fill the gap between the viral and cellular worlds. These giant viruses are also uniquely equipped with genes coding for central components of the translation apparatus. The presence of those genes, thought to be hallmarks of cellular organisms, revived fundamental interrogations on the evolutionary origin of these viruses and the link they might have with the emergence of eukaryotes. In this work, we focused on the Mimivirus-encoded translation termination factor gene, the detailed primary structure of which was elucidated using computational and experimental approaches. We demonstrated that the translation of this protein proceeds through two internal stop codons via two distinct recoding events: a frameshift and a readthrough, the combined occurrence of which is unique to these viruses. Unexpectedly, the viral gene carries an autoregulatory mechanism exclusively encountered in bacterial termination factors, though the viral sequence is related to the eukaryotic/archaeal class-I release factors. This finding is a hint that the virally-encoded translation functions may not be strictly redundant with the one provided by the host. Lastly, the perplexing occurrence of a bacterial-like regulatory mechanism in a eukaryotic/archaeal homologous gene is yet another oddity brought about by the study of giant viruses. PMID:23271980

  1. 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 574nm. The SMBV genome contains 938 ORFs, of which nine are ORFans. The 1,213.6kb 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

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

    PubMed

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

    2015-09-22

    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

  3. Zika Virus Infection

    MedlinePLUS

    ... The General Public For Health Authorities Videos on Zika Virus ??? Zika, a new threat. What is it? ... Dengue, chikungunya y zika - Jornada arbovirosis 2015 - Argentina Zika affected areas Zika Resources Missions to support countries ...

  4. Zika Virus Infection

    MedlinePLUS

    ... of Disease Still Unclear PAHO answers questions about mosquito control for Zika Virus Sesame Street Muppets Join PAHO to Educate Families About Preventing Zika Mosquito Bites Misión de la OPS/OMS propone reforzar ...

  5. 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

  6. Chikungunya virus infection: an overview.

    PubMed

    Caglioti, Claudia; Lalle, Eleonora; Castilletti, Concetta; Carletti, Fabrizio; Capobianchi, Maria Rosaria; Bordi, Licia

    2013-07-01

    Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus belonging to the Togaviridae family, first isolated in Tanzania in 1952. The main vectors are mosquitoes from the Aedes species. Recently, the establishment of an envelope mutation increased infectivity for A. albopictus. CHIKV has recently re-emerged causing millions of infections in countries around the Indian Ocean characterized by climate conditions favourable to high vector density. Importation of human cases to European regions with high density of suitable arthropod vectors (such as A. albopictus) may trigger autochthonous outbreaks. The clinical signs of CHIKV infection include non-specific flu-like symptoms, and a characteristic rash accompanied by joint pain that may last for a long time after the resolution of the infection. The death rate is not particularly high, but excess mortality has been observed in concomitance with large CHIKV outbreaks. Deregulation of innate defense mechanisms, such as cytokine inflammatory response, may participate in the main clinical signs of CHIKV infection, and the establishment of persistent (chronic) disease. There is no specific therapy, and prevention is the main countermeasure. Prevention is based on insect control and in avoiding mosquito bites in endemic countries. Diagnosis is based on the detection of virus by molecular methods or by virus culture on the first days of infection, and by detection of an immune response in later stages. CHIKV infection must be suspected in patients with compatible clinical symptoms returning from epidemic/endemic areas. Differential diagnosis should take into account the cross-reactivity with other viruses from the same antigenic complex (i.e. O'nyong-nyong virus). PMID:23912863

  7. 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, 30678 simple sequence repeats (SSRs) from all spleen samples, 26355 single nucleotide polymorphisms (SNPs) from the spleens of uninfected animals and 36070 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

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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; Cout, 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 ?m 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 ?m 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 ?m 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

  13. Characterization of Chinese giant salamander iridovirus tissue tropism and inflammatory response after infection.

    PubMed

    Jiang, Nan; Fan, Yuding; Zhou, Yong; Liu, Wenzhi; Ma, Jie; Meng, Yan; Xie, Congxin; Zeng, Lingbing

    2015-06-01

    The Chinese giant salamander iridovirus (GSIV), belonging to the genus Ranavirus in the family Iridoviridae, causes severe hemorrhagic lesions and nearly 100% mortality in naturally infected Chinese giant salamanders Andrias davidiamus. However, the replication and distribution of the virus has not been well characterized in vivo. Using in situ hybridization, the expression of the GSIV major capsid protein (MCP) was detected in the cytoplasm of cells of the spleen, kidney, liver and gut tissues. MCP expression in the spleen and kidney appeared to fluctuate significantly during the acute phase of infection. Using an immunofluorescence assay, GSIV antigens were abundant in the spleen and kidney tissues but appeared to be at relatively low levels in the liver and gut. Additionally, there were significant changes in the expression of the pro-inflammatory cytokines macrophage migration inhibitory factor (MIF), tumor necrosis factor ? (TNF-?) and interleukin-1? (IL-1?) in different tissues in response to infection with GSIV. The expression of MIF, TNF-? and IL-1? had significantly increased in the spleen at 3 d post-infection; this correlated with a decrease in virus replication in the spleen. These results suggest that the spleen and kidney are the major target tissues of GSIV, and the increased expression of MIF, TNF?? and IL-1? may contribute to a reduction of virus replication in the spleen. PMID:26036830

  14. 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

  15. Discrete virus infection model of hepatitis B virus.

    PubMed

    Zhang, Pengfei; Min, Lequan; Pian, Jianwei

    2015-01-01

    In 1996 Nowak and his colleagues proposed a differential equation virus infection model, which has been widely applied in the study for the dynamics of hepatitis B virus (HBV) infection. Biological dynamics may be described more practically by discrete events rather than continuous ones. Using discrete systems to describe biological dynamics should be reasonable. Based on one revised Nowak et al's virus infection model, this study introduces a discrete virus infection model (DVIM). Two equilibriums of this model, E1 and E2, represents infection free and infection persistent, respectively. Similar to the case of the basic virus infection model, this study deduces a basic virus reproductive number R0 independing on the number of total cells of an infected target organ. A proposed theorem proves that if the basic virus reproductive number R0<1 then the virus free equilibrium E1 is locally stable. The DVIM is more reasonable than an abstract discrete susceptible-infected-recovered model (SIRS) whose basic virus reproductive number R0 is relevant to the number of total cells of the infected target organ. As an application, this study models the clinic HBV DNA data of a patient who was accepted via anti-HBV infection therapy with drug lamivudine. The results show that the numerical simulation is good in agreement with the clinic data. PMID:26405998

  16. 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

  17. Getah Virus Infection among Racehorses, Japan, 2014.

    PubMed

    Nemoto, Manabu; Bannai, Hiroshi; Tsujimura, Koji; Kobayashi, Minoru; Kikuchi, Takuya; Yamanaka, Takashi; Kondo, Takashi

    2015-05-01

    An outbreak of Getah virus infection occurred among racehorses in Japan during September and October 2014. Of 49 febrile horses tested by reverse transcription PCR, 25 were positive for Getah virus. Viruses detected in 2014 were phylogenetically different from the virus isolated in Japan in 1978. PMID:25898181

  18. Swine influenza virus infections in humans.

    PubMed

    Dowdle, W R; Hattwick, M A

    1977-12-01

    Influenza in swine was first recognized as an epizootic disease in 1918. During that same year influenza virus in humans caused the worst pandemic on record. The virus of swine influenza was isolated in 1930. Swine influenza virus was first isolated from humans in 1974. Since then, including the cases at Fort Dix, there have been a total of nine viral isolations from humans in the United States. Serologic evidence of infections with swine influenza virus in humans has also been obtained. Evidence for transmission of swine influenza virus to humans before 1974 is minimal and circumstantial. Recent recognition of infections with swine influenza virus may be the result of better surveillance, increased numbers of susceptible humans, or increased viral infectivity for humans. Nevertheless, the apparent frequency of human infections and the declining levels of antibodies to swine influenza virus in the human population suggest that influenza viruses of swine may be a potential sources of epidemic disease for humans. PMID:342616

  19. Screening of parasitic and IHHNV infections in wild giant freshwater prawn Macrobrachium rosenbergii from Rejang River at Kuching, Sarawak.

    PubMed

    Kua, Beng Chu; Choong, F C; Hazreen Nita, M K; Muhd Faizul H, A H; Bhassu, S; Imelda, R R; Mohammed, M

    2011-04-01

    A preliminary survey of parasitic and infectious hypodermal and haematopoietic necrosis virus (IHHNV) infections in giant freshwater prawn from the Damak Sea of Rejang River, Kuching, Sarawak was conducted. Symptoms of black spots/patches on the rostrum, carapace, pleopods or telson were observed in most of the 107 samples collected. Parasitic examination revealed sessiline peritrichs such as (Zoothamnium sp.), nematode larvae, gregarine stage and cocoon of leech with prevalences of 1.2%, 1.2%, 5% and 17% respectively. Under histopathological examination, changes like accumulation of hemocytes around hepatopancreatic tubules due to vibriosis, basophilic intranuclear inclusions in the epithelium and E-cell of hepatopancreatic tubules as a result of HPV were seen through the section. No positive infection of IHHNV was detected in 78 samples. As such, the wild giant freshwater prawns in Damak Sea of Rejang River in Kuching are IHHNV-free though infections of parvo-like virus and bacteria were seen in histopathology. PMID:21602773

  20. 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

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

    PubMed

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

    2015-04-01

    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

  2. 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...

  3. Nipah virus infection: current scenario.

    PubMed

    Kulkarni, D D; Tosh, C; Venkatesh, G; Senthil Kumar, D

    2013-12-01

    The emergence of Nipah virus (NiV) infection into the pig population and subsequently into the human population is believed to be due to changes in ecological conditions. In Malaysia, A major NiV outbreak occurred in pigs and humans from September 1998 to April 1999 that resulted in infection of 265 and death of 105 persons. About 1.1 million pigs had to be destroyed to control the outbreak. The disease was recorded in the form of a major outbreak in India in 2001 and then a small incidence in 2007, both the outbreaks in West Bengal only in humans without any involvement of pigs. There were series of human Nipah incidences in Bangladesh from 2001 till 2013 almost every year with mortality exceeding 70%. The disease transmission from pigs acting as an intermediate host during Malaysian and Singapore outbreaks has changed in NIV outbreaks in India and Bangladesh, transmitting the disease directly from bats to human followed by human to human. The drinking of raw date palm sap contaminated with fruit bat urine or saliva containing NiV is the only known cause of outbreak of the disease in Bangladesh outbreaks. The virus is now known to exist in various fruit bats of Pteropus as well as bats of other genera in a wider belt from Asia to Africa. PMID:24426305

  4. Mimiviridae: clusters of orthologous genes, reconstruction of gene repertoire evolution and proposed expansion of the giant virus family

    PubMed Central

    2013-01-01

    Background The family Mimiviridae belongs to the large monophyletic group of Nucleo-Cytoplasmic Large DNA Viruses (NCLDV; proposed order Megavirales) and encompasses giant viruses infecting amoeba and probably other unicellular eukaryotes. The recent discovery of the Cafeteria roenbergensis virus (CroV), a distant relative of the prototype mimiviruses, led to a substantial expansion of the genetic variance within the family Mimiviridae. In the light of these findings, a reassessment of the relationships between the mimiviruses and other NCLDV and reconstruction of the evolution of giant virus genomes emerge as interesting and timely goals. Results Database searches for the protein sequences encoded in the genomes of several viruses originally classified as members of the family Phycodnaviridae, in particular Organic Lake phycodnaviruses and Phaeocystis globosa viruses (OLPG), revealed a greater number of highly similar homologs in members of the Mimiviridae than in phycodnaviruses. We constructed a collection of 898 Clusters of Orthologous Genes for the putative expanded family Mimiviridae (MimiCOGs) and used these clusters for a comprehensive phylogenetic analysis of the genes that are conserved in most of the NCLDV. The topologies of the phylogenetic trees for these conserved viral genes strongly support the monophyly of the OLPG and the mimiviruses. The same tree topology was obtained by analysis of the phyletic patterns of conserved viral genes. We further employed the mimiCOGs to obtain a maximum likelihood reconstruction of the history of genes losses and gains among the giant viruses. The results reveal massive gene gain in the mimivirus branch and modest gene gain in the OLPG branch. Conclusions These phylogenomic results reported here suggest a substantial expansion of the family Mimiviridae. The proposed expanded family encompasses a greater diversity of viruses including a group of viruses with much smaller genomes than those of the original members of the Mimiviridae. If the OLPG group is included in an expanded family Mimiviridae, it becomes the only family of giant viruses currently shown to host virophages. The mimiCOGs are expected to become a key resource for phylogenomics of giant viruses. PMID:23557328

  5. Giant viruses, giant chimeras: The multiple evolutionary histories of Mimivirus genes

    PubMed Central

    2008-01-01

    Background Although capable to evolve, viruses are generally considered non-living entities because they are acellular and devoid of metabolism. However, the recent publication of the genome sequence of the Mimivirus, a giant virus that parasitises amoebas, strengthened the idea that viruses should be included in the tree of life. In fact, the first phylogenetic analyses of a few Mimivirus genes that are also present in cellular lineages suggested that it could define an independent branch in the tree of life in addition to the three domains, Bacteria, Archaea and Eucarya. Results We tested this hypothesis by carrying out detailed phylogenetic analyses for all the conserved Mimivirus genes that have homologues in cellular organisms. We found no evidence supporting Mimivirus as a new branch in the tree of life. On the contrary, our phylogenetic trees strongly suggest that Mimivirus acquired most of these genes by horizontal gene transfer (HGT) either from its amoebal hosts or from bacteria that parasitise the same hosts. The detection of HGT events involving different eukaryotic donors suggests that the spectrum of hosts of Mimivirus may be larger than currently known. Conclusion The large number of genes acquired by Mimivirus from eukaryotic and bacterial sources suggests that HGT has been an important process in the evolution of its genome and the adaptation to parasitism. PMID:18205905

  6. Systems analysis of West Nile virus infection

    PubMed Central

    Suthar, Mehul S.; Pulendran, Bali

    2014-01-01

    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 based 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

  7. Microbiome in human immunodeficiency virus infection.

    PubMed

    Salas, January T; Chang, Theresa L

    2014-12-01

    Human immunodeficiency virus (HIV) primary infection occurs at mucosa tissues, suggesting an intricate interplay between the microbiome and HIV infection. Recent advanced technologies of high-throughput sequencing and bioinformatics allow researchers to explore nonculturable microbes, including bacteria, virus, and fungi, and their association with diseases. HIV/simian immunodeficiency virus infection is associated with microbiome shifts and immune activation that may affect the outcome of disease progression. In this review, the authors focus on microbiome in HIV infection at various mucosal compartments. Understanding the relationship between microbiome and HIV may offer insights into development of better strategies for HIV prevention and treatment. PMID:25439273

  8. Visualizing influenza virus infection in living mice.

    PubMed

    Pan, Weiqi; Dong, Zhenyuan; Li, Feng; Meng, Weixu; Feng, Liqiang; Niu, Xuefeng; Li, Chufang; Luo, Qinfang; Li, Zhengfeng; Sun, Caijun; Chen, Ling

    2013-01-01

    Preventing and treating influenza virus infection remain a challenge because of incomplete understanding of the host-pathogen interactions, limited therapeutics and lack of a universal vaccine. So far, methods for monitoring the course of infection with influenza virus in real time in living animals are lacking. Here we report the visualization of influenza viral infection in living mice using an engineered replication-competent influenza A virus carrying luciferase reporter gene. After intranasal inoculation, bioluminescence can be detected in the chest and nasopharyngeal passage of living mice. The intensity of bioluminescence in the chest correlates with the dosage of infection and the viral load in the lung. Bioluminescence in the chest of infected mice diminishes on antiviral treatment. This work provides a novel approach that enables real-time study of influenza virus infection and effects of antiviral therapeutics in living animals. PMID:24022374

  9. Visualizing influenza virus infection in living mice

    PubMed Central

    Pan, Weiqi; Dong, Zhenyuan; Li, Feng; Meng, Weixu; Feng, Liqiang; Niu, Xuefeng; Li, Chufang; Luo, Qinfang; Li, Zhengfeng; Sun, Caijun; Chen, Ling

    2013-01-01

    Preventing and treating influenza virus infection remain a challenge because of incomplete understanding of the hostpathogen interactions, limited therapeutics and lack of a universal vaccine. So far, methods for monitoring the course of infection with influenza virus in real time in living animals are lacking. Here we report the visualization of influenza viral infection in living mice using an engineered replication-competent influenza A virus carrying luciferase reporter gene. After intranasal inoculation, bioluminescence can be detected in the chest and nasopharyngeal passage of living mice. The intensity of bioluminescence in the chest correlates with the dosage of infection and the viral load in the lung. Bioluminescence in the chest of infected mice diminishes on antiviral treatment. This work provides a novel approach that enables real-time study of influenza virus infection and effects of antiviral therapeutics in living animals. PMID:24022374

  10. 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

  11. Ebola Virus Infection: What Should Be Known?

    PubMed Central

    Wiwanitkit, Viroj

    2014-01-01

    Ebola virus infection is the present global consideration. This deadly virus can result in a deadly acute febrile hemorrhagic illness. The patient can have several clinical manifestations. As a new emerging infection, the knowledge on this infection is extremely limited. The interesting issues to be discussed include a) the atypical clinical presentation, b) new diagnostic tool, c) new treatment, and d) disease prevention. Those topics will be discussed in this special review. PMID:25535601

  12. Heat shock response to vaccinia virus infection.

    PubMed Central

    Sedger, L; Ruby, J

    1994-01-01

    We have investigated the induction of heat shock proteins (HSPs) in mice infected with vaccinia virus. Vaccinia virus replicates to high levels in the ovaries of infected mice and causes a significant inhibition of host cell DNA, RNA, and protein synthesis. Many HSPs are constitutively expressed in murine ovarian tissue at low levels, consistent with their obligatory role in normal physiological events. In contrast with these events, HSP expression was augmented in virus-infected mouse ovaries 6 days postinfection. In particular, there was a dramatic increase in the expression of a protein identified as the inducible 72-kDa HSP. Analysis of cellular mRNA confirmed this protein to be the major mouse inducible HSP70 and demonstrated its presence within virus-infected cells. Hence, we have demonstrated the expression of stress proteins during poxvirus infection in vivo. Images PMID:8207845

  13. DNA-dependent RNA polymerase detects hidden giant viruses in published databanks.

    PubMed

    Sharma, Vikas; Colson, Philippe; Giorgi, Roch; Pontarotti, Pierre; Raoult, Didier

    2014-07-01

    Environmental metagenomic studies show that there is a "dark matter," composed of sequences not linked to any known organism, as determined mainly using ribosomal DNA (rDNA) sequences, which therefore ignore giant viruses. DNA-dependent RNA polymerase (RNAP) genes are universal in microbes and conserved in giant viruses and may replace rDNA for identifying microbes. We found while reconstructing RNAP subunit 2 (RNAP2) phylogeny that a giant virus sequenced together with the genome of a large eukaryote, Hydra magnipapillata, has been overlooked. To explore the dark matter, we used viral RNAP2 and reconstructed putative ancestral RNAP2, which were significantly superior in detecting distant clades than current sequences, and we revealed two additional unknown mimiviruses, misclassified as an euryarchaeote and an oomycete plant pathogen, and detected unknown putative viral clades. We suggest using RNAP systematically to decipher the black matter and identify giant viruses. PMID:24929085

  14. DNA-Dependent RNA Polymerase Detects Hidden Giant Viruses in Published Databanks

    PubMed Central

    Sharma, Vikas; Colson, Philippe; Giorgi, Roch; Pontarotti, Pierre; Raoult, Didier

    2014-01-01

    Environmental metagenomic studies show that there is a “dark matter,” composed of sequences not linked to any known organism, as determined mainly using ribosomal DNA (rDNA) sequences, which therefore ignore giant viruses. DNA-dependent RNA polymerase (RNAP) genes are universal in microbes and conserved in giant viruses and may replace rDNA for identifying microbes. We found while reconstructing RNAP subunit 2 (RNAP2) phylogeny that a giant virus sequenced together with the genome of a large eukaryote, Hydra magnipapillata, has been overlooked. To explore the dark matter, we used viral RNAP2 and reconstructed putative ancestral RNAP2, which were significantly superior in detecting distant clades than current sequences, and we revealed two additional unknown mimiviruses, misclassified as an euryarchaeote and an oomycete plant pathogen, and detected unknown putative viral clades. We suggest using RNAP systematically to decipher the black matter and identify giant viruses. PMID:24929085

  15. 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

  16. 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

  17. Occult hepatitis B virus infection

    PubMed Central

    Kwak, Min-Sun; Kim, Yoon Jun

    2014-01-01

    Occult hepatitis B virus (HBV) infection (OBI) refers to the presence of HBV DNA in the absence of detectable hepatitis B surface antigen. Since OBI was first described in the late 1970s, there has been increasing interest in this topic. The prevalence of OBI varies according to the different endemicity of HBV infection, cohort characteristics, and sensitivity and specificity of the methods used for detection. Although the exact mechanism of OBI has not been proved, intra-hepatic persistence of viral covalently closed circular DNA under the hosts strong immune suppression of HBV replication and gene expression seems to be a cause. OBI has important clinical significance in several conditions. First, OBI can be transmitted through transfusion, organ transplantation including orthotopic liver transplantation, or hemodialysis. Donor screening before blood transfusion, prophylaxis for high-risk organ transplantation recipients, and dialysis-specific infection-control programs should be considered to reduce the risk of transmission. Second, OBI may reactivate and cause acute hepatitis in immunocompromised patients or those receiving chemotherapy. Close HBV DNA monitoring and timely antiviral treatment can prevent HBV reactivation and consequent clinical deterioration. Third, OBI may contribute to the progression of hepatic fibrosis in patients with chronic liver disease including hepatitis C. Finally, OBI seems to be a risk factor for hepatocellular carcinoma by its direct proto-oncogenic effect and by indirectly causing persistent hepatic inflammation and fibrosis. However, this needs further investigation. We review published reports in the literature to gain an overview of the status of OBI and emphasize the clinical importance of OBI. PMID:25544873

  18. 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

  19. Ebola virus infection modeling and identifiability problems

    PubMed Central

    Nguyen, Van Kinh; Binder, Sebastian C.; Boianelli, Alessandro; Meyer-Hermann, Michael; Hernandez-Vargas, Esteban A.

    2015-01-01

    The recent outbreaks of Ebola virus (EBOV) infections have underlined the impact of the virus as a major threat for human health. Due to the high biosafety classification of EBOV (level 4), basic research is very limited. Therefore, the development of new avenues of thinking to advance quantitative comprehension of the virus and its interaction with the host cells is urgently needed to tackle this lethal disease. Mathematical modeling of the EBOV dynamics can be instrumental to interpret Ebola infection kinetics on quantitative grounds. To the best of our knowledge, a mathematical modeling approach to unravel the interaction between EBOV and the host cells is still missing. In this paper, a mathematical model based on differential equations is used to represent the basic interactions between EBOV and wild-type Vero cells in vitro. Parameter sets that represent infectivity of pathogens are estimated for EBOV infection and compared with influenza virus infection kinetics. The average infecting time of wild-type Vero cells by EBOV is slower than in influenza infection. Simulation results suggest that the slow infecting time of EBOV could be compensated by its efficient replication. This study reveals several identifiability problems and what kind of experiments are necessary to advance the quantification of EBOV infection. A first mathematical approach of EBOV dynamics and the estimation of standard parameters in viral infections kinetics is the key contribution of this work, paving the way for future modeling works on EBOV infection. PMID:25914675

  20. 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.

  1. 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

  2. [Imported Zika virus infection in the Netherlands].

    PubMed

    von Eije, K J; Schinkel, J; van den Kerkhof, J H C T; Schreuder, I; de Jong, M D; Grobusch, M P; Goorhuis, A

    2015-01-01

    Since mid-2015, a rapidly expanding outbreak of Zika virus infection is spreading across Latin America and the Caribbean. Although Zika virus infection usually causes only mild disease, the World Health Organization has declared the epidemiological association with the occurrence of congenital microcephaly and neurological complications a 'Public Health Emergency of International Concern' and urged the international community to mount a coordinated international response aimed to protect people at risk, especially pregnant women. In December 2015, the first case of imported Zika virus infection in the Netherlands was diagnosed in a returned traveler from Surinam. To date, more than 20 cases have been reported in The Netherlands, all imported from Surinam. We describe the epidemiology, clinical aspects, diagnostic challenges and the existing evidence to date that link Zika virus infection to complications. PMID:26906886

  3. METHODS USED TO STUDY RESPIRATORY VIRUS INFECTION

    PubMed Central

    Flao, 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

  4. Imported Mayaro virus infection in the Netherlands.

    PubMed

    Hassing, Robert-Jan; Leparc-Goffart, Isabelle; Blank, Sybrandus N; Thevarayan, Subashini; Tolou, Hugues; van Doornum, Gerard; van Genderen, Perry J

    2010-10-01

    A Dutch couple, presenting with persisting arthralgias, temporary fever and rash after a stay in Surinam were diagnosed with Mayaro virus infection. Mayaro virus is a relatively unknown South American Alphavirus responsible for dengue-like clinical features and persisting arthralgias. An important, but probably underappreciated cross-reactivity with other Alphaviruses like Chikungunya virus is present, which may become of clinical importance in the event the various Alphaviruses will have overlapping geographical distributions and in seroprevalence studies. PMID:20600300

  5. Lipid interactions during virus entry and infection

    PubMed Central

    Mazzon, Michela; Mercer, Jason

    2014-01-01

    Summary For entry and infection viruses have developed numerous strategies to subjugate indispensable cellular factors and functions. Host cell lipids and cellular lipid synthesis machinery are no exception. Not only do viruses exploit existing lipid signalling and modifications for virus entry and trafficking, they also reprogram lipid synthesis, metabolism, and compartmentalization for assembly and egress. Here we review these various concepts and highlight recent progress in understanding viral interactions with host cell lipids during entry and assembly. PMID:25131438

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

    PubMed Central

    Gallot-Lavalle, Lucie; Pagarete, Antnio; 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

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

    PubMed

    Gallot-Lavalle, Lucie; Pagarete, Antnio; Legendre, Matthieu; Santini, Sebastien; Sandaa, Ruth-Anne; Himmelbauer, Heinz; Ogata, Hiroyuki; Bratbak, Gunnar; Claverie, Jean-Michel

    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

  8. Nipah virus infection in dogs, Malaysia, 1999.

    PubMed

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

    2009-06-01

    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

  9. 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

  10. 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

  11. Mimivirus and Mimiviridae: giant viruses with an increasing number of potential hosts, including corals and sponges.

    PubMed

    Claverie, Jean-Michel; Grzela, Renata; Lartigue, Audrey; Bernadac, Alain; Nitsche, Serge; Vacelet, Jean; Ogata, Hiroyuki; Abergel, Chantal

    2009-07-01

    Mimivirus, a giant DNA virus (i.e. "girus") infecting species of the genus Acanthamoeba, was first identified in 2003. With a particle size of 0.7microm in diameter, and a genome size of 1.2Mb encoding more than 900 proteins, it is the most complex virus described to date. Beyond its unusual size, the Mimivirus genome was found to contain the first viral homologues of many genes thought to be the trademark of cellular organisms, such as central components of the translation apparatus. These findings revived the debate on the origin of DNA viruses, and the role they might have played in the emergence of eukaryotes. Published and ongoing studies on Mimivirus continue to lead to unexpected findings concerning a variety of aspects, such as the structure of its particle, unique features of its replication cycle, or the distribution and abundance of Mimivirus relatives in the oceans. Following a summary of these recent findings, we present preliminary results suggesting that octocorals might have come in close contact with an ancestor of Mimivirus, and that modern sponges might be host to a yet unidentified, even larger, member of the Mimiviridae. PMID:19457438

  12. 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

  13. Virus Infection-Induced Bronchial Asthma Exacerbation

    PubMed Central

    Yamaya, Mutsuo

    2012-01-01

    Infection with respiratory viruses, including rhinoviruses, influenza virus, and respiratory syncytial virus, exacerbates asthma, which is associated with processes such as airway inflammation, airway hyperresponsiveness, and mucus hypersecretion. In patients with viral infections and with infection-induced asthma exacerbation, inflammatory mediators and substances, including interleukins (ILs), leukotrienes and histamine, have been identified in the airway secretions, serum, plasma, and urine. Viral infections induce an accumulation of inflammatory cells in the airway mucosa and submucosa, including neutrophils, lymphocytes and eosinophils. Viral infections also enhance the production of inflammatory mediators and substances in airway epithelial cells, mast cells, and other inflammatory cells, such as IL-1, IL-6, IL-8, GM-CSF, RANTES, histamine, and intercellular adhesion molecule-1. Viral infections affect the barrier function of the airway epithelial cells and vascular endothelial cells. Recent reports have demonstrated augmented viral production mediated by an impaired interferon response in the airway epithelial cells of asthma patients. Several drugs used for the treatment of bronchial asthma reduce viral and pro-inflammatory cytokine release from airway epithelial cells infected with viruses. Here, I review the literature on the pathogenesis of the viral infection-induced exacerbation of asthma and on the modulation of viral infection-induced airway inflammation. PMID:22966430

  14. 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 ...

  15. Molecular biology of hepatitis B virus infection.

    PubMed

    Seeger, Christoph; Mason, William S

    2015-05-01

    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 lifelong, 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

  16. 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.

  17. 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

  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. 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...

  20. Chronic Rabies Virus Infection of Cell Cultures

    PubMed Central

    Wiktor, T. J.; Clark, H F.

    1972-01-01

    Exposure of both mammalian and reptilian cells in tissue culture to different strains of fixed rabies virus resulted in a carrier type of infection. No cytopathic effect was observed in either type of culture; infected cultures could be maintained by cell transfer for unlimited numbers of passages. A consistent pattern of cyclically rising and falling levels of viral infection was observed by fluorescent-antibody staining techniques and by titration of released infectious virus. Resistance to super-infection by vesicular stomatis virus and the production of an interferon-like substance by infected cells indicated that the maintenance of a carrier type of infection may be interferon-mediated. The degree of susceptibility of rabies-infected cells to immunolysis by antirabies antibody in the presence of complement was found to be correlated with the amount of virus maturation occurring by budding through the cell membrane and not with the presence of immunofluorescent antigen in the cytoplasm of infected cells. Images PMID:4344636

  1. 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

  2. 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

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

    PubMed

    Abraho, Jnatas S; Dornas, Fbio P; Silva, Lorena C F; Almeida, Gabriel M; Boratto, Paulo V M; Colson, Phillipe; La Scola, Bernard; Kroon, Erna G

    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

  4. 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

  5. Quantifying the infectivity of human immunodeficiency virus.

    PubMed Central

    Layne, S P; Spouge, J L; Dembo, M

    1989-01-01

    We have developed a mathematical model that quantifies lymphocyte infection by human immunodeficiency virus (HIV) and lymphocyte protection by blocking agents such as soluble CD4. We use this model to suggest standardized parameters for quantifying viral infectivity and to suggest techniques for calculating these parameters from well-mixed infectivity assays. We discuss the implications of the model for our understanding of the infectious process and virulence of HIV in vivo. PMID:2734313

  6. 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

  7. 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

  8. Host-virus interactions in hepatitis B virus infection.

    PubMed

    Guidotti, Luca G; Isogawa, Masanori; Chisari, Francis V

    2015-10-01

    Hepatitis B virus (HBV) is a noncytopathic, hepatotropic, double-stranded DNA virus that causes acute and chronic hepatitis. Although HBV does not induce a measurable innate immune response in the infected liver, the outcome of infection is determined by the kinetics, breadth, vigor, trafficking, and effector functions of HBV-specific adaptive T cell responses, and the development of neutralizing antibodies. Dysregulation of one or more of these events leads to persistent HBV infection and a variably severe chronic necroinflammatory liver disease that fosters the development of hepatocellular carcinoma. Deeper understanding of the mechanisms responsible for immunological tolerance to HBV is needed in order to devise immunotherapeutic strategies to cure chronic HBV infection and prevent its life-threatening sequelae. PMID:26186123

  9. Varicella Zoster Virus (Chickenpox) Infection in Pregnancy

    PubMed Central

    Lamont, Ronald F.; Sobel, Jack D; Carrington, D; Mazaki-Tovi, Shali; Kusanovic, Juan Pedro; Vaisbuch, Edi; Romero, Roberto

    2011-01-01

    Congenital varicella syndrome, maternal varicella zoster virus pneumonia and neonatal varicella infection are associated with serious feto-maternal morbidity and not infrequently with mortality. Vaccination against Varicella zoster virus can prevent the disease and outbreak control limits the exposure of pregnant women to the infectious agent. Maternal varicella zoster immune globulin (VZIG) administration before rash development, with or without antivirals medications can modify progression of the disease. PMID:21585641

  10. Persistence in herpes simplex virus infections.

    PubMed Central

    Longson, M.

    1978-01-01

    Diseases of man caused by the virus of herpes simplex fall into two broad categories. The primary disease occurs only once in any individual's life and is caused by transmission of virus from an already infected human. Thereafter, the individual may be subject to recurrent herpetic disease, the manifestations of which are different from the primary disease. Recurrent disease varies in severity from trivial, to incapacitating and frankly lethal (as in diseases resulting from the virus's neurotropic and oncogenic properties). The source of the virus in recurrent herpetic disease has never been conclusively resolved, but is almost certainly endogenous to the patient. Theories, case reports and experiments exist to show that endogenous virus may, in periods of clinical quiescence, be latent (or persistent) at the site of the recurrent lesions itself, or more remotely in nerve tissues related to the site of recurrence. Images Fig. 1 PMID:214773

  11. 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

  12. Parainfluenza virus 5 expressing the G protein of rabies virus protects mice after rabies virus infection.

    PubMed

    Huang, Ying; Chen, Zhenhai; Huang, Junhua; Fu, ZhenFang; He, Biao

    2015-03-01

    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

  13. Borna disease virus infection in cats.

    PubMed

    Wensman, Jonas Johansson; Jäderlund, Karin Hultin; Holst, Bodil Ström; Berg, Mikael

    2014-08-01

    Bornaviruses are known to cause neurological disorders in a number of animal species. Avian Bornavirus (ABV) causes proventricular dilatation disease (PDD) in birds and Borna disease virus (BDV) causes Borna disease in horses and sheep. BDV also causes staggering disease in cats, characterised by ataxia, behavioural changes and loss of postural reactions. BDV-infection markers in cats have been reported throughout the world. This review summarizes the current knowledge of Borna disease viruses in cats, including etiological agent, clinical signs, pathogenesis, epidemiology and diagnostics, with comparisons to Bornavirus infections in other species. PMID:24480411

  14. 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

  15. Identification of type I IFN in Chinese giant salamander (Andrias davidianus) and the response to an iridovirus infection.

    PubMed

    Chen, Qian; Ma, Jie; Fan, Yuding; Meng, Yan; Xu, Jin; Zhou, Yong; Liu, Wenzhi; Zeng, Xianhui; Zeng, Lingbing

    2015-06-01

    The type I IFNs play a major role in the first line of defense against virus infections. In this study, the type I IFN gene designated gsIFN was identified and characterized in the Chinese giant salamander (Andrias davidianus). The genomic DNA of gsIFN contains 5 exons and 4 introns and has a total length of 5622 bp. The full-length cDNA sequence of gsIFN is 1113 bp and encodes a putative protein of 186 amino acids that has a 43% identity to type I IFN of Xenopus tropicalis. The deduced amino acid sequence has the C-terminal CAWE motif, that is mostly conserved in the higher vertebrate type I IFNs. Real-time fluorescence quantitative RT-PCR analysis revealed broad expression of gsIFN in vivo and the highest level expression in blood, kidney and spleen. Additionally, the expression of gsIFN at the mRNA level was significantly induced in peripheral blood leucocytes after stimulation with poly I:C and after infection with the Chinese giant salamander iridovirus (GSIV). A plasmid expressing gsIFN was constructed and transfected into the Chinese giant salamander muscle cell line. Expression of the IFN-inducible gene Mx was up-regulated in the gsIFN-overexpressing cells after GSIV infection. The virus load and titer were significantly reduced compared with that in control cells. Additionally, a lower level of virus major capsid protein synthesis was confirmed by immunofluorescence assay compared to the control cells. These results suggest that the gsIFN gene plays an important role in the antiviral innate immune response. PMID:25733388

  16. 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

  17. Apoptosis in virus infection dynamics models

    PubMed Central

    Fan, Ruili; Dong, Yueping; Huang, Gang; Takeuchi, Yasuhiro

    2014-01-01

    In this paper, on the basis of the simplified two-dimensional virus infection dynamics model, we propose two extended models that aim at incorporating the influence of activation-induced apoptosis which directly affects the population of uninfected cells. The theoretical analysis shows that increasing apoptosis plays a positive role in control of virus infection. However, after being included the third population of cytotoxic T lymphocytes immune response in HIV-infected patients, it shows that depending on intensity of the apoptosis of healthy cells, the apoptosis can either promote or comfort the long-term evolution of HIV infection. Further, the discrete-time delay of apoptosis is incorporated into the pervious model. Stability switching occurs as the time delay in apoptosis increases. Numerical simulations are performed to illustrate the theoretical results and display the different impacts of a delay in apoptosis. PMID:24963975

  18. 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 ?M 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

  19. Pseudorabies virus infection in Oklahoma hunting dogs.

    PubMed

    Cramer, Sarah D; Campbell, Gregory A; Njaa, Bradley L; Morgan, Sandra E; Smith, Stephen K; McLin, William R; Brodersen, Bruce W; Wise, Annabel G; Scherba, Gail; Langohr, Ingeborg M; Maes, Roger K

    2011-09-01

    Pseudorabies is caused by Suid herpesvirus 1, a member of the Alphaherpesvirinae subfamily. Although pigs are the natural host of Pseudorabies virus (PRV), the virus has a broad host range and may cause fatal encephalitis in many species. The United States obtained PRV-free status in 2004 after the virus was eradicated from domestic swineherds, but the virus is still present in feral swine populations. The current report describes PRV infection in 3 dogs that were used to hunt feral swine. The dogs developed clinical signs including facial pruritus with facial abrasions, dyspnea, vomiting, diarrhea, ataxia, muscle stiffness, and death. Two were euthanized, and 1 died within approximately 48 hr after onset of clinical signs. The salient histologic changes consisted of neutrophilic trigeminal ganglioneuritis with neuronophagia and equivocal intranuclear inclusion bodies. Pseudorabies virus was isolated from fresh tissues from 2 of the dogs, and immunohistochemistry detected the virus in the third dog. Virus sequencing and phylogeny, based upon available GenBank sequences, revealed that the virus was likely a field strain that was closely related to a cluster of PRV strains previously identified in Illinois. Though eradicated from domestic swine in the United States, PRV is present in populations of feral swine, and should therefore continue to be considered a possible cause of disease in dogs and other domestic animals with compatible clinical history and signs. Continued surveillance is necessary to prevent reintroduction of PRV into domestic swine. PMID:21908347

  20. The rapidly expanding universe of giant viruses: Mimivirus, Pandoravirus, Pithovirus and Mollivirus.

    PubMed

    Abergel, Chantal; Legendre, Matthieu; Claverie, Jean-Michel

    2015-11-01

    More than a century ago, the term 'virus' was introduced to describe infectious agents that are invisible by light microscopy and capable of passing through sterilizing filters. In addition to their extremely small size, most viruses have minimal genomes and gene contents, and rely almost entirely on host cell-encoded functions to multiply. Unexpectedly, four different families of eukaryotic 'giant viruses' have been discovered over the past 10 years with genome sizes, gene contents and particle dimensions overlapping with that of cellular microbes. Their ongoing analyses are challenging accepted ideas about the diversity, evolution and origin of DNA viruses. PMID:26391910

  1. Origin of the Transmitted Virus in HIV Infection: Infected Cells Versus Cell-Free Virus

    PubMed Central

    Sagar, Manish

    2014-01-01

    All human immunodeficiency virus type 1 (HIV-1)infected inocula, such as genital secretions, breast milk, and blood, contain both cell-free virus and infected cells. The relative contributions of cell-free and/or cell-associated virus in establishing an infection in a naive host during the different modes of HIV-1 acquisition remains unclear. Studies aim to elucidate the source of the acquired virus because strategies to prevent acquisition may have differential efficacy against the different modes of transmission. In this review, I will detail some of the challenges in identifying the source of the transmitted virus, genotypic and phenotypic differences among cell-free compared with cell-associated HIV-1, and implications on the efficacy for prevention strategies. PMID:25414422

  2. Bacterial Infections, DNA Virus Infections, and RNA Virus Infections Manifest Differently in Neutrophil Receptor Expression

    PubMed Central

    Lilius, Esa-Matti; Nuutila, Jari

    2012-01-01

    Treating viral illnesses or noninfective causes of inflammation with antibiotics is ineffective and contributes to the development of antibiotic resistance, toxicity, and allergic reactions, leading to increasing medical costs. A major factor behind unnecessary use of antibiotics is, of course, incorrect diagnosis. For this reason, timely and accurate information on whether the infection is bacterial in origin would be highly beneficial. In this paper we will present our recent studies on the expression of opsonin receptors on phagocytes. The analysis of the expression levels of Fc?RI, CR1, and CR3, along with CRP and ESR data, provides a novel application to the diagnosis of infectious and inflammatory diseases. The best clinical benefit will be obtained when the individual variables are combined to generate the CIS point method for a bacterial infection marker, DNAVS point for differentiating between DNA and RNA virus infections, and CRP/CD11b ratio for a marker of Gram-positive sepsis. PMID:22536142

  3. BK-virus infections: a literature review.

    PubMed

    Siguier, M; Sellier, P; Bergmann, J-F

    2012-05-01

    BK-virus is a very common polyomavirus in the global population, similar to the JC-virus responsible for Progressive Multifocal Leukoencephalopathy. BK-virus infections are an important diagnostic and therapeutic challenge in immuno-compromised patients, including: bone marrow transplant pediatric recipients in whom it may cause hemorrhagic cystitis, renal transplant recipients in whom it may cause interstitial nephropathy leading to graft loss, and in HIV infected patients in whom it may cause some types of encephalitis. Indeed, this poorly documented virus is responsible for infections with various clinical profiles, probably under-diagnosed, but could also be involved in the genesis of some cancers, especially cervix and prostate cancer. We reviewed the latest published data on this virus focusing on its possible pro-oncogenic properties. We also listed the diseases in which it is involved, with an emphasis on rare and insufficiently investigated entities. Finally, we studied the new tools available for diagnosis and treatment, and their importance in current practice. PMID:22621826

  4. Characterization of a UDP-N-acetylglucosamine biosynthetic pathway encoded by the giant DNA virus Mimivirus.

    PubMed

    Piacente, Francesco; Bernardi, Cinzia; Marin, Margherita; Blanc, Guillaume; Abergel, Chantal; Tonetti, Michela G

    2014-01-01

    Mimivirus is a giant DNA virus belonging to the Megaviridae family and infecting unicellular Eukaryotes of the genus Acanthamoeba. The viral particles are characterized by heavily glycosylated surface fibers. Several experiments suggest that Mimivirus and other related viruses encode an autonomous glycosylation system, forming viral glycoproteins independently of their host. In this study, we have characterized three Mimivirus proteins involved in the de novo uridine diphosphate-N-acetylglucosamine (UDP-GlcNAc) production: a glutamine-fructose-6-phosphate transaminase (CDS L619), a glucosamine-6-phosphate N-acetyltransferase (CDS L316) and a UDP-GlcNAc pyrophosphorylase (CDS R689). Sequence and enzymatic analyses have revealed some unique features of the viral pathway. While it follows the eukaryotic-like strategy, it also shares some properties of the prokaryotic pathway. Phylogenetic analyses revealed that the Megaviridae enzymes cluster in monophyletic groups, indicating that they share common ancestors, but did not support the hypothesis of recent acquisitions from one of the known hosts. Rather, viral clades branched at deep nodes in phylogenetic trees, forming independent clades outside sequenced cellular organisms. The intermediate properties between the eukaryotic and prokaryotic pathways, the phylogenetic analyses and the fact that these enzymes are shared between most of the known members of the Megaviridae family altogether suggest that the viral pathway has an ancient origin, resulting from lateral transfers of cellular genes early in the Megaviridae evolution, or from vertical inheritance from a more complex cellular ancestor (reductive evolution hypothesis). The identification of a virus-encoded UDP-GlcNAc pathway reinforces the concept that GlcNAc is a ubiquitous sugar representing a universal and fundamental process in all organisms. PMID:24107487

  5. 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

  6. 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)

  7. Transmission of human infection with Nipah virus.

    PubMed

    Luby, Stephen P; Gurley, Emily S; Hossain, M Jahangir

    2009-12-01

    Nipah virus (NiV) is a paramyxovirus whose reservoir host is fruit bats of the genus Pteropus. Occasionally the virus is introduced into human populations and causes severe illness characterized by encephalitis or respiratory disease. The first outbreak of NiV was recognized in Malaysia, but 8 outbreaks have been reported from Bangladesh since 2001. The primary pathways of transmission from bats to people in Bangladesh are through contamination of raw date palm sap by bats with subsequent consumption by humans and through infection of domestic animals (cattle, pigs, and goats), presumably from consumption of food contaminated with bat saliva or urine with subsequent transmission to people. Approximately one-half of recognized Nipah case patients in Bangladesh developed their disease following person-to-person transmission of the virus. Efforts to prevent transmission should focus on decreasing bat access to date palm sap and reducing family members' and friends' exposure to infected patients' saliva. PMID:19886791

  8. A case of Ebola virus infection.

    PubMed

    Emond, R T; Evans, B; Bowen, E T; Lloyd, G

    1977-08-27

    In November 1976 an investigator at the Microbiological Research Establishment accidentally inoculated himself while processing material from patients in Africa who had been suffering from a haemorrhagic fever of unknown cause. He developed an illness closely resembling Marburg disease, and a virus was isolated from his blood that resembled Marburg virus but was distinct serologically. The course of the illness was mild and may have been modified by treatment with human interferon and convalescent serum. Convalescence was protracted; there was evidence of bone-marrow depression and virus was excreted in low titre for some weeks. Recovery was complete. Infection was contained by barrier-nursing techniques using a negative-pressure plastic isolator and infection did not spread to attendant staff or to the community. PMID:890413

  9. 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

  10. A case of Ebola virus infection.

    PubMed Central

    Emond, R T; Evans, B; Bowen, E T; Lloyd, G

    1977-01-01

    In November 1976 an investigator at the Microbiological Research Establishment accidentally inoculated himself while processing material from patients in Africa who had been suffering from a haemorrhagic fever of unknown cause. He developed an illness closely resembling Marburg disease, and a virus was isolated from his blood that resembled Marburg virus but was distinct serologically. The course of the illness was mild and may have been modified by treatment with human interferon and convalescent serum. Convalescence was protracted; there was evidence of bone-marrow depression and virus was excreted in low titre for some weeks. Recovery was complete. Infection was contained by barrier-nursing techniques using a negative-pressure plastic isolator and infection did not spread to attendant staff or to the community. PMID:890413

  11. 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...

  12. 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

  13. Bovine model of respiratory syncytial virus infection.

    PubMed

    Taylor, Geraldine

    2013-01-01

    Bovine respiratory syncytial virus (BRSV), which is an important cause of respiratory disease in young calves, is genetically and antigenically closely related to human (H)RSV. The epidemiology and pathogenesis of infection with these viruses are similar. The viruses are host-specific and infection produces a spectrum of disease ranging from subclinical to severe bronchiolitis and pneumonia, with the peak incidence of severe disease in individuals less than 6 months of age. BRSV infection in calves reproduces many of the clinical signs associated with HRSV in infants, including fever, rhinorrhoea, coughing, harsh breath sounds and rapid breathing. Although BRSV vaccines have been commercially available for decades, there is a need for greater efficacy. The development of effective BRSV and HRSV vaccines face similar challenges, such as the need to vaccinate at an early age in the presence of maternal antibodies, the failure of natural infection to prevent reinfection, and a history of vaccine-augmented disease. Neutralising monoclonal antibodies (mAbs) to the fusion (F) protein of HRSV, which can protect infants from severe HRSV disease, recognise the F protein of BRSV, and vice versa. Furthermore, bovine and human CD8(+) T-cells, which are known to be important in recovery from RSV infection, recognise similar proteins that are conserved between HRSV and BRSV. Therefore, not only can the bovine model of RSV be used to evaluate vaccine concepts, it can also be used as part of the preclinical assessment of certain HRSV candidate vaccines. PMID:24362697

  14. The cell biology of Chikungunya virus infection.

    PubMed

    Tang, Bor Luen

    2012-09-01

    Chikungunya virus (CHIKV) infection causes a disease which appears to affect multiple cell types and tissues. The acute phase is manifested by a non-fatal febrile illness, polyarthralgia and maculopapular rashes in adults, but with recurrent arthralgia that may linger for months during convalescence. The issue of cellular and tissue tropism of CHIKV has elicited interest primarily because of this lingering incapacitating chronic joint pain, as well as clear encephalopathy in severe cases among neonates during the re-emergence of the virus in recent epidemics. The principle cell types productively infected by CHIKV are skin fibroblasts, epithelial cells and lymphoid tissues. There is controversy as to whether CHIKV productively infects haematopoietic cells and neurones/glia. CHIKV infection triggers rapid and robust innate immune responses which quickly clears the acute phase infection. However, significant acute as well as chronic infection of less obvious cell types, such as monocytes, neurones/glia or even CNS neural progenitors may conceivably occur. There is therefore a need to ascertain the full range potential of CHIKV tropism, fully understand the cellular responses triggered during the acute the convalescent phases, and explore possible cell types that might be the source of chronic problems associated with CHIKV infection. PMID:22686853

  15. Hepatitis B virus infection in children.

    PubMed

    Komatsu, Haruki; Inui, Ayano

    2015-04-01

    For two decades, hepatitis B vaccine has been integrated into national routine childhood vaccination programs in almost all countries. The prevalence of HBsAg has decreased in children worldwide. However, there are children who miss the benefit of hepatitis B vaccine in some regions and countries. Long-term follow-up studies have revealed the clinical outcomes of chronic hepatitis B virus infection in children. A small percentage of chronically infected children develop liver cirrhosis and hepatocellular carcinoma. However, it is controversial who should be treated and when antiviral treatment should be initiated in children. Compared with adult studies, the data are insufficient to evaluate the pathogenesis of hepatitis B infection and the efficacy of antiviral treatment in childhood. New antiviral drugs have been approved for children and adults. Also, oral antiviral drugs are administered to pregnant women to reduce the hepatitis B virus mother-to-child transmission rate. PMID:25724218

  16. Hepatitis C virus infection and apoptosis

    PubMed Central

    Fischer, Richard; Baumert, Thomas; Blum, Hubert E

    2007-01-01

    Apoptosis is central for the control and elimination of viral infections. In chronic hepatitis C virus (HCV) infection, enhanced hepatocyte apoptosis and upregulation of the death inducing ligands CD95/Fas, TRAIL and TNF? occur. Nevertheless, HCV infection persists in the majority of patients. The impact of apoptosis in chronic HCV infection is not well understood. It may be harmful by triggering liver fibrosis, or essential in interferon (IFN) induced HCV elimination. For virtually all HCV proteins, pro- and anti-apoptotic effects have been described, especially for the core and NS5A protein. To date, it is not known which HCV protein affects apoptosis in vivo and whether the infectious virions act pro- or anti-apoptotic. With the availability of an infectious tissue culture system, we now can address pathophysiologically relevant issues. This review focuses on the effect of HCV infection and different HCV proteins on apoptosis and of the corresponding signaling cascades. PMID:17828818

  17. 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

  18. Epstein-Barr virus infection and neoplasia.

    PubMed

    Sprinkle, P M; Veltri, R W

    1981-01-01

    Once acquired, Epstein-Barr virus (EBV), a latent virus, remains in the body for what appears to be the lifetime of the human host. Circumstantial data suggest EBV is involved in clinical disease including malignancies far more often than previously recognized. A serologic test for early antigen (EA) is more specific for diagnosing active EBV disease than the monospot or heterophile test. A case study of active Epstein-Barr infection is reported showing persistently elevated early antigen titers prior to and following malignant transformation. PMID:6270614

  19. Current treatment of hepatitis B virus infections.

    PubMed

    De Clercq, Erik

    2015-11-01

    Chronic hepatitis B virus (HBV) infection remains an important global burden with an estimated 240 million HBV carriers worldwide and more than half a million people dying annually from the consequences of the HBV infection. Besides interferon and pegylated interferon, there are five antiviral drugs [lamivudine, adefovir (dipivoxil), entecavir, telbivudine, and tenofovir disoproxil fumarate] that have proved effective in the treatment of chronic hepatitis B. These five antiviral drugs interfere with viral DNA synthesis, which consists of a step reminiscent of the reverse transcriptase step in the replicative cycle of HIV. None of the antiviral drugs, or interferon, are capable of eradicating the covalently closed circular DNA, which remains settled as an episome within the virus-infected hepatocytes. In the short-term (1-3?years), the use of antiviral treatment is aimed at reducing viral DNA below levels of detection, whereas in the long term (10?years and, possibly, lifelong), treatment is aimed at reducing the progression to cirrhosis, hepatocellular carcinoma, liver decompensation, and death. As long as the virus can hide as the episomal covalently closed circular DNA, attempts to envisage a definite cure of the HBV infection may seem fortuitous. Copyright 2015 John Wiley & Sons, Ltd. PMID:26205627

  20. 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

  1. Zebrafish: modeling for herpes simplex virus infections.

    PubMed

    Antoine, Thessicar Evadney; Jones, Kevin S; Dale, Rodney M; Shukla, Deepak; Tiwari, Vaibhav

    2014-02-01

    For many years, zebrafish have been the prototypical model for studies in developmental biology. In recent years, zebrafish has emerged as a powerful model system to study infectious diseases, including viral infections. Experiments conducted with herpes simplex virus type-1 in adult zebrafish or in embryo models are encouraging as they establish proof of concept with viral-host tropism and possible screening of antiviral compounds. In addition, the presence of human homologs of viral entry receptors in zebrafish such as 3-O sulfated heparan sulfate, nectins, and tumor necrosis factor receptor superfamily member 14-like receptor bring strong rationale for virologists to test their in vivo significance in viral entry in a zebrafish model and compare the structure-function basis of virus zebrafish receptor interaction for viral entry. On the other end, a zebrafish model is already being used for studying inflammation and angiogenesis, with or without genetic manipulations, and therefore can be exploited to study viral infection-associated pathologies. The major advantage with zebrafish is low cost, easy breeding and maintenance, rapid lifecycle, and a transparent nature, which allows visualizing dissemination of fluorescently labeled virus infection in real time either at a localized region or the whole body. Further, the availability of multiple transgenic lines that express fluorescently tagged immune cells for in vivo imaging of virus infected animals is extremely attractive. In addition, a fully developed immune system and potential for receptor-specific knockouts further advocate the use of zebrafish as a new tool to study viral infections. In this review, we focus on expanding the potential of zebrafish model system in understanding human infectious diseases and future benefits. PMID:24266790

  2. 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.

  3. 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

  4. Hepatitis C virus infection in nephrology patients

    PubMed Central

    Rostaing, Lionel; Izopet, Jacques; Kamar, Nassim

    2013-01-01

    Context: Hepatitis C virus (HCV) infection leads to chronic liver disease, but also to extra-hepatic manifestations. Evidence Acquisitions: Directory of Open Access Journals (DOAJ), Google Scholar, Pubmed (NLM), LISTA (EBSCO) and Web of Science have been searched. Results: Herein, we provide an overview of renal diseases related to HCV and their therapies, as well as the treatment options available for HCV (+)/RNA (+) dialysis patients. We will not mention, however, HCV infection-related complications in the post-kidney transplantation setting. Conclusions: Extra-hepatic manifestations of HCV infection include mixed cryoglobulinemia, lymphoproliferative disorders, and renal disease. HCV infection has been reported in association with distinct histological patterns of glomerulonephritis in native kidneys. PMID:24475454

  5. Myeloradiculopathy associated with chikungunya virus infection.

    PubMed

    Bank, Anna M; Batra, Ayush; Colorado, Rene A; Lyons, Jennifer L

    2016-02-01

    Chikungunya virus (CHIKV) is a mosquito-borne alphavirus that is endemic to parts of Africa, South and Southeast Asia, and more recently the Caribbean. Patients typically present with fever, rash, and arthralgias, though neurologic symptoms, primarily encephalitis, have been described. We report the case of a 47-year-old woman who was clinically diagnosed with CHIKV while traveling in the Dominican Republic and presented 10days later with left lower extremity weakness, a corresponding enhancing thoracic spinal cord lesion, and positive CHIKV serologies. She initially responded to corticosteroids, followed by relapsing symptoms and gradual clinical improvement. The time lapse between acute CHIKV infection and the onset of myelopathic sequelae suggests an immune-mediated phenomenon rather than direct activity of the virus itself. Chikungunya virus should be considered in the differential diagnosis of myelopathy in endemic areas. The progression of symptoms despite corticosteroid administration suggests more aggressive immunomodulatory therapies may be warranted at disease onset. PMID:26306687

  6. [Hepatitis B virus infection in children].

    PubMed

    Czajka, H; Mizerski, J; Gorczyca, A; Bobrzyńska, J

    1993-01-01

    Retrospective analysis of 256 medical records of children with confirmed diagnosis of hepatitis B virus infection was done. The study focused on significance of patient's age and sex in the course of the disease, on circumstance accompanying the HBV infection and on course of infection, especially a chronic HBV infection. It has been found that factors increasing the risk of infection include: former hospitalizations, surgical procedures, malfunctions of an immune system and familial contacts. Hepatitis occurred more frequently in infants and young children and in this age it more often converted into a chronic form. The course of hepatitis infection depended on dynamics of the disease process. Seroconversion occurred more often after acute phase of the disease and asymptomatic course of infection most often resulted in chronic form. Treatment with immuno-potent (TFX, isoprinosine) had no effect on the course of hepatitis B infection. It should be recommended to extend prophylaxis to children of the risk group and to introduce routine test for HBs antigen in each inpatient child. PMID:8234842

  7. 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...

  8. Hepatitis C Virus Infection and Nonalcoholic Steatohepatitis

    PubMed Central

    Patel, Anish

    2012-01-01

    Nonalcoholic fatty-liver disease (NAFLD) is one of the most prevalent liver diseases in the Western hemisphere. The rising rates of obesity and diabetes mellitus correlate with the increasing incidence of NAFLD, which is the hepatic manifestation of metabolic syndrome. Hepatitis C virus infection is another common cause of liver disease worldwide. Up to 70% of patients with chronic hepatitis C (CHC) will have concomitant steatosis. The presence of NAFLD has been implicated as a cause of lower viral response rates in CHC patients who are treated with pegylated interferon and ribavirin. This review will focus on the factors that lead to NAFLD in the setting of hepatitis C virus infection, including viral and host factorsin particular, inflammatory mediators, cytokines, and lipid peroxidation. This paper will also discuss the implications of NAFLD and nonalcoholic steatohepatitis regarding fibrosis progression, risk of hepatocellular carcinoma, and limitations with antiviral therapy. PMID:22933860

  9. Dendritic cells and influenza A virus infection.

    PubMed

    Waithman, Jason; Mintern, Justine D

    2012-11-15

    Influenza A virus (IAV) is a dangerous virus equipped with the potential to evoke widespread pandemic disease. The 2009 H1N1 pandemic highlights the urgency for developing effective therapeutics against IAV infection. Vaccination is a major weapon to combat IAV and efforts to improve current regimes are critically important. Here, we will review the role of dendritic cells (DCs), a pivotal cell type in the initiation of robust IAV immunity. The complexity of DC subset heterogeneity in the respiratory tract and lymph node that drains the IAV infected lung will be discussed, together with the varied and in some cases, conflicting contributions of individual DC populations to presenting IAV associated antigen to T cells. PMID:23076333

  10. Prevention of respiratory syncytial virus infection

    PubMed Central

    Samson, L

    2009-01-01

    Respiratory syncytial virus (RSV) infection is the leading cause of lower respiratory tract infection in young children, with significant numbers of premature infants and those with other risk factors requiring hospitalization in Canada each year. Palivizumab, an RSV-specific monoclonal antibody, can reduce the hospitalization rate and severity of illness for a small group of high-risk or premature infants during their first RSV season. The present statement reviews the published literature and provides recommendations regarding its use in premature and other at-risk infants, for Canadian physicians. PMID:20885804

  11. Animal Models of Varicella Zoster Virus Infection

    PubMed Central

    Haberthur, Kristen; Messaoudi, Ilhem

    2013-01-01

    Primary infection with varicella zoster virus (VZV) results in varicella (chickenpox) followed by the establishment of latency in sensory ganglia. Declining T cell immunity due to aging or immune suppressive treatments can lead to VZV reactivation and the development of herpes zoster (HZ, shingles). HZ is often associated with significant morbidity and occasionally mortality in elderly and immune compromised patients. There are currently two FDA-approved vaccines for the prevention of VZV: Varivax (for varicella) and Zostavax (for HZ). Both vaccines contain the live-attenuated Oka strain of VZV. Although highly immunogenic, a two-dose regimen is required to achieve a 99% seroconversion rate. Zostavax vaccination reduces the incidence of HZ by 51% within a 3-year period, but a significant reduction in vaccine-induced immunity is observed within the first year after vaccination. Developing more efficacious vaccines and therapeutics requires a better understanding of the host response to VZV. These studies have been hampered by the scarcity of animal models that recapitulate all aspects of VZV infections in humans. In this review, we describe different animal models of VZV infection as well as an alternative animal model that leverages the infection of Old World macaques with the highly related simian varicella virus (SVV) and discuss their contributions to our understanding of pathogenesis and immunity during VZV infection. PMID:25437040

  12. 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.

  13. Chaperones in hepatitis C virus infection.

    PubMed

    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

  14. 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

  15. Influenza A virus infections in swine: pathogenesis and diagnosis.

    PubMed

    Janke, B H

    2014-03-01

    Influenza has been recognized as a respiratory disease in swine since its first appearance concurrent with the 1918 "Spanish flu" human pandemic. All influenza viruses of significance in swine are type A, subtype H1N1, H1N2, or H3N2 viruses. Influenza viruses infect epithelial cells lining the surface of the respiratory tract, inducing prominent necrotizing bronchitis and bronchiolitis and variable interstitial pneumonia. Cell death is due to direct virus infection and to insult directed by leukocytes and cytokines of the innate immune system. The most virulent viruses consistently express the following characteristics of infection: (1) higher or more prolonged virus replication, (2) excessive cytokine induction, and (3) replication in the lower respiratory tract. Nearly all the viral proteins contribute to virulence. Pigs are susceptible to infection with both human and avian viruses, which often results in gene reassortment between these viruses and endemic swine viruses. The receptors on the epithelial cells lining the respiratory tract are major determinants of infection by influenza viruses from other hosts. The polymerases, especially PB2, also influence cross-species infection. Methods of diagnosis and characterization of influenza viruses that infect swine have improved over the years, driven both by the availability of new technologies and by the necessity of keeping up with changes in the virus. Testing of oral fluids from pigs for virus and antibody is a recent development that allows efficient sampling of large numbers of animals. PMID:24363301

  16. 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

  17. Vaccinia Virus Infections in Martial Arts Gym, Maryland, USA, 2008

    PubMed Central

    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.

    2011-01-01

    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

  18. Development of therapeutics for treatment of Ebola virus infection.

    PubMed

    Li, Haoyang; Ying, Tianlei; Yu, Fei; Lu, Lu; Jiang, Shibo

    2015-02-01

    Ebola virus infection can cause Ebola virus disease (EVD). Patients usually show severe symptoms, and the fatality rate can reach up to 90%. No licensed medicine is available. In this review, development of therapeutics for treatment of Ebola virus infection and EVD will be discussed. PMID:25498866

  19. REGULATION OF APOPTOSIS IN AFRICAN SWINE FEVER VIRUS INFECTED MACROPHAGES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A number of viruses have evolved antiapoptotic mechanisms to promote infected-cell survival, either to ensure efficient productive viral replication or to promote long-term survival of virus-infected cells. Recent studies identified critical African swine fever virus genes involved in the complex re...

  20. 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.

  1. 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

  2. Interferon production and virus replication in lymphoblastoid cells infected with different viruses.

    PubMed

    Heremans, H; de Ley, M; Volckaert-Vervliet, G; Billiau, A

    1980-01-01

    A semicontinuous infection system was used to test viral replication and interferon induction in lymphoblastoid cells: measles virus, Newcastle disease virus (NDV), Sendai virus, human parainfluenza virus (type II and III), Semliki forest virus (SFV) and Vesicular stomatitis virus (VSV). With the exception of Sendai virus, all viruses replicated in the Namalva cell line. Only measles virus was able to induce high levels of interferon. Three other cell lines, NC37, Raji (TK+-variant) and Raji (TK--variant) were tested using measles virus as inducer. The interferon yields from these cells were inferior to those obtained from Namalva cells. PMID:6243928

  3. Immunobiology of hepatitis B virus infection.

    PubMed

    Isogawa, Masanori; Tanaka, Yasuhito

    2015-01-01

    The adaptive immune response, particularly the virus-specific CD8(+) T-cell response, is largely responsible for viral clearance and disease pathogenesis during hepatitis B virus (HBV) infection. The HBV-specific CD8(+) T-cell response is vigorous, polyclonal and multispecific in acutely infected patients who successfully clear the virus and relatively weak and narrowly focused in chronically infected patients. The immunological basis for this dichotomy is unclear. A recent study using HBV transgenic mice and HBV-specific T-cell receptor transgenic mice suggests that intrahepatic antigen presentation by HBV positive hepatocytes suppresses HBV-specific CD8(+) T-cell responses through a co-inhibitory molecule, programmed cell death 1 (PD-1). In contrast, antigen presentation by activated professional antigen-presenting cells induces functional differentiation of HBV-specific CD8(+) T cells. These findings suggest that the outcome of T-cell priming is largely dependent on the nature of antigen-presenting cells. Another study suggests that the timing of HBV-specific CD4(+) T-cell priming regulates the magnitude of the HBV-specific CD8(+) T-cell response. Other factors that could regulate HBV-specific cellular immune responses are high viral loads, mutational epitope inactivation, T-cell receptor antagonism and infection of immunologically privileged tissues. However, these pathways become apparent only in the setting of an ineffective cellular immune response, which is therefore the fundamental underlying cause. Understanding the cellular and molecular mechanisms by which HBV evades host immune responses will eventually help develop new immunotherapeutic strategies designed to terminate chronic HBV infection. PMID:25331910

  4. West Nile Virus: Biology, Transmission, and Human Infection

    PubMed Central

    Colpitts, Tonya M.; Conway, Michael J.; Montgomery, Ruth R.

    2012-01-01

    Summary: West Nile Virus was introduced into the Western Hemisphere during the late summer of 1999 and has been causing significant and sometimes severe human diseases since that time. This article briefly touches upon the biology of the virus and provides a comprehensive review regarding recent discoveries about virus transmission, virus acquisition, and human infection and disease. PMID:23034323

  5. Significance of blood analysis in hemophiliacs co-infected with human immunodeficiency virus and hepatitis viruses

    PubMed Central

    Shen, Fang; Huang, Qin; Sun, Hong-Qing; Ghildyal, Reena

    2007-01-01

    AIM: To study the effect of hepatitis virus infection on cirrhosis and liver function markers in HIV-infected hemophiliacs. METHODS: We have analyzed the immunological, liver function and cirrhosis markers in a cohort of hemophiliacs co-infected with human immunodeficiency virus (HIV) and hepatitis viruses. RESULTS: There was no difference in immunological markers among co-infected patients and patients infected with HIV only and those co-infected with one or more hepatitis virus. Although liver function and cirrhosis markers remained within a normal range, there was a worsening trend in all patients co-infected with hepatitis virus C (HCV), which was further exacerbated in the presence of additional infection with hepatitis virus B (HBV). CONCLUSION: Co-infection with HIV, HBV and HCV leads to worsening of hyaluronic acid and liver function markers. Increases in serum hyaluronic acid may be suggestive of a predisposition to liver diseases. PMID:17465482

  6. Virus Clearance through Apoptosis-Dependent Phagocytosis of Influenza A Virus-Infected Cells by Macrophages

    PubMed Central

    Fujimoto, Ippei; Pan, Jiehong; Takizawa, Takenori; Nakanishi, Yoshinobu

    2000-01-01

    Some cultured cell lines undergo typical apoptosis upon infection with influenza virus. However, the release of replicated virus into the culture medium does not change when apoptosis is inhibited. Since apoptotic cells are heterophagically eliminated at early stages of the apoptosis pathway, we anticipated that the coexistence of phagocytic cells with virus-infected cells affects the extent of virus growth. When influenza A virus-infected HeLa cells were mixed with activated mouse peritoneal macrophages, efficient phagocytosis, which was abrogated in the presence of a caspase inhibitor, occurred. At the same time, the release of virus into the culture medium was completely inhibited, and this required direct contact between virus-infected cells and macrophages. Furthermore, an immunoelectron microscopic analysis detected influenza virus particles associated with phagosome-like structures within macrophages. These results indicate that apoptosis-dependent phagocytosis of virus-infected cells may lead to direct elimination of the pathogen. PMID:10708457

  7. Neurobiology of LCM virus infection in rodents

    PubMed Central

    Monjan, A. A.; Bohl, L. S.; Hudgens, G. A.

    1975-01-01

    In addition to the previously reported data on the retinal and cerebellar immunopathology following infection of neonatal rats with LCM virus, we have found that there are long-term effects on behavioural and neurological development. Rats were inoculated intracerebrally with the E-350 strain at different ages during the first 3 weeks after birth. Behavioural tests were initiated when the animals were either 3 months or 1 year of age. The behavioural consequences appear to be a long-term alteration in emotional reactivity such that the infected animals are less responsive than controls as assessed by these measures. No alterations were detected in animals infected after the first postnatal week. Complementing these data are the findings of a collaterally progressive lesion of the hippocampal dentate gyrus as well as a loss in total cell number in the forebrain (as assessed by DNA, RNA, and protein determinations) amounting to about 20% of the brain mass. These behavioural, histological, and biochemical data indicate that there are forebrain structures, most probably within the limbic system, that are susceptible at critical phases of development to the pathological consequences of infection with LCM virus. PMID:1085208

  8. 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

  9. 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...

  10. 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 ...

  11. 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

  12. 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

  13. Hepatitis C virus infection and insulin resistance

    PubMed Central

    Bose, Sandip K; Ray, Ranjit

    2014-01-01

    Approximately 170 million people worldwide are chronically infected with hepatitis C virus (HCV). Chronic HCV infection is the leading cause for the development of liver fibrosis, cirrhosis, hepatocellular carcinoma (HCC) and is the primary cause for liver transplantation in the western world. Insulin resistance is one of the pathological features in patients with HCV infection and often leads to development of type II diabetes. Insulin resistance plays an important role in the development of various complications associated with HCV infection. Recent evidence indicates that HCV associated insulin resistance may result in hepatic fibrosis, steatosis, HCC and resistance to anti-viral treatment. Thus, HCV associated insulin resistance is a therapeutic target at any stage of HCV infection. HCV modulates normal cellular gene expression and interferes with the insulin signaling pathway. Various mechanisms have been proposed in regard to HCV mediated insulin resistance, involving up regulation of inflammatory cytokines, like tumor necrosis factor-?, phosphorylation of insulin-receptor substrate-1, Akt, up-regulation of gluconeogenic genes like glucose 6 phosphatase, phosphoenolpyruvate carboxykinase 2, and accumulation of lipid droplets. In this review, we summarize the available information on how HCV infection interferes with insulin signaling pathways resulting in insulin resistance. PMID:24567801

  14. 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

  15. Hepatitis B virus infection in immigrant populations.

    PubMed

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

    2015-12-28

    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

  16. Pathogenesis of human immunodeficiency virus infection and prospects for control.

    PubMed Central

    Ho, D. D.; Kaplan, J. C.

    1987-01-01

    In just six years after the initial description of the acquired immunodeficiency syndrome, much has been learned about the etiologic agent, the human immunodeficiency virus. The pathogenic mechanisms utilized by this virus to infect selectively and persistently T4+ lymphocytes and monocyte/macrophages, leading to immunodeficiency and neurologic dysfunction, are slowly becoming clear. Better understanding of the pathogenesis of human immunodeficiency virus infection is essential for the rational design of therapeutic and preventive strategies to combat this deadly virus. PMID:3324508

  17. [Diagnosis of fetal virus infections by in situ hybridization].

    PubMed

    Mehraein, Y; Rehder, H; Draeger, H G; Froster-Iskenius, U G; Schwinger, E; Holzgreve, W

    1991-12-01

    Non-radioactive in situ hybridization of formalin-fixed paraffin-embedded placental and foetal tissue, using virus-specific DNA or RNA probes, may be helpful for the diagnosis of foetal virus infection causing foetal hydrops, granulomatous placentitis and abortion. We present four cases of intrauterine CMV-, Parvo-B19- and Varicella-Zoster virus infection, in which this diagnostic method established detection of the virus. PMID:1665465

  18. Imunocompetent Mice Model for Dengue Virus Infection

    PubMed Central

    Gonalves, Denise; de Queiroz Prado, Rafael; Almeida Xavier, Eric; Cristina de Oliveira, Natlia; da Matta Guedes, Paulo Marcos; da Silva, Joo Santana; Moraes Figueiredo, Luiz Tadeu; Aquino, Victor Hugo

    2012-01-01

    Dengue fever is a noncontagious infectious disease caused by dengue virus (DENV). DENV belongs to the family Flaviviridae, genus Flavivirus, and is classified into four antigenically distinct serotypes: DENV-1, DENV-2, DENV-3, and DENV-4. The number of nations and people affected has increased steadily and today is considered the most widely spread arbovirus (arthropod-borne viral disease) in the world. The absence of an appropriate animal model for studying the disease has hindered the understanding of dengue pathogenesis. In our study, we have found that immunocompetent C57BL/6 mice infected intraperitoneally with DENV-1 presented some signs of dengue disease such as thrombocytopenia, spleen hemorrhage, liver damage, and increase in production of IFN? and TNF? cytokines. Moreover, the animals became viremic and the virus was detected in several organs by real-time RT-PCR. Thus, this animal model could be used to study mechanism of dengue virus infection, to test antiviral drugs, as well as to evaluate candidate vaccines. PMID:22666132

  19. Ebola virus (EBOV) infection: Therapeutic strategies.

    PubMed

    De Clercq, Erik

    2015-01-01

    Within less than a year after its epidemic started (in December 2013) in Guinea, Ebola virus (EBOV), a member of the filoviridae, has spread over a number of West-African countries (Guinea, Sierra Leone and Liberia) and gained allures that have been unprecedented except by human immunodeficiency virus (HIV). Although EBOV is highly contagious and transmitted by direct contact with body fluids, it could be counteracted by the adequate chemoprophylactic and -therapeutic interventions: vaccines, antibodies, siRNAs (small interfering RNAs), interferons and chemical substances, i.e. neplanocin A derivatives (i.e. 3-deazaneplanocin A), BCX4430, favipiravir (T-705), endoplasmic reticulum (ER) ?-glucosidase inhibitors and a variety of compounds that have been found to inhibit EBOV infection blocking viral entry or by a mode of action that still has to be resolved. Much has to be learned from the mechanism of action of the compounds active against VSV (vesicular stomatitis virus), a virus belonging to the rhabdoviridae, that in its mode of replication could be exemplary for the replication of filoviridae. PMID:25481298

  20. Long-term productive human immunodeficiency virus-1 infection in human infant microglia.

    PubMed Central

    Ioannidis, J. P.; Reichlin, S.; Skolnik, P. R.

    1995-01-01

    The course of human immunodeficiency virus 1 (HIV-1) infection in human infant microglia was studied using purified primary cultures of microglia derived from brain autopsy tissue. Previous in vitro studies have used fetal or adult brain tissue. Important differences may exist between brain tissues of different maturational ages with regard to HIV-1 replication and other neuropathogenic effects. Infant microglia were infected with four different strains of HIV-1 (JR-FL, JR-CSF, Ba-L, and IIIB). Productive infection was demonstrated by p24 antigen production, immunocytochemistry, and recovery of replication-competent virus from the supernatants of the infected cultures. Multinucleated giant cells developed in culture mimicking the neuropathological changes seen in the brains of patients with HIV encephalopathy. Productive infection was more readily established by monocyte-tropic strains (JR-FL and Ba-L) of HIV-1 than by a lymphocyte-tropic strain (IIIB). p24 antigen production in this system peaked at 47 to 51 days postinfection. Viral persistence in giant cells was demonstrated by immunocytochemistry for the gp120 and gp41 viral antigens as late as 70 days postinfection. This in vitro culture system, using infant microglia that support viral replication for more than 2 months, may provide a useful model for studying the pathogenesis of progressive HIV encephalopathy. Images Figure 1 PMID:7485383

  1. Phosphatidylinositol inhibits respiratory syncytial virus infection.

    PubMed

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

    2015-03-01

    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 >10(3). 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

  2. Antibody-Dependent Enhancement of Ebola Virus Infection

    PubMed Central

    Takada, Ayato; Feldmann, Heinz; Ksiazek, Thomas G.; Kawaoka, Yoshihiro

    2003-01-01

    Most strains of Ebola virus cause a rapidly fatal hemorrhagic disease in humans, yet there are still no biologic explanations that adequately account for the extreme virulence of these emerging pathogens. Here we show that Ebola Zaire virus infection in humans induces antibodies that enhance viral infectivity. Plasma or serum from convalescing patients enhanced the infection of primate kidney cells by the Zaire virus, and this enhancement was mediated by antibodies to the viral glycoprotein and by complement component C1q. Our results suggest a novel mechanism of antibody-dependent enhancement of Ebola virus infection, one that would account for the dire outcome of Ebola outbreaks in human populations. PMID:12805454

  3. [Skin symptoms associated with human immunodeficiency virus infection].

    PubMed

    Tamsi, Bla; Marschalk, Mrta; Krpti, Sarolta

    2015-01-01

    The recently observed accelerated increase of human immunodeficiency virus infection in Hungary poses a major public concern for the healthcare system. Given the effective only but not the curative therapy, prevention should be emphasized. Current statistics estimate that about 50% of the infected persons are not aware of their human immunodeficiency virus-positivity. Thus, early diagnosis of the infection by serological screening and timely recognition of the disease-associated symptoms are crucial. The authors' intention is to facilitate early infection detection with this review on human immunodeficiency virus-associated skin symptoms, and highlight the significance of human immunodeficiency virus care in the everyday medical practice. PMID:25544049

  4. Autophagic flux without a block differentiates varicella-zoster virus infection from herpes simplex virus infection

    PubMed Central

    Buckingham, Erin M.; Carpenter, John E.; Jackson, Wallen; Zerboni, Leigh; Arvin, Ann M.; Grose, Charles

    2015-01-01

    Autophagy is a process by which misfolded and damaged proteins are sequestered into autophagosomes, before degradation in and recycling from lysosomes. We have extensively studied the role of autophagy in varicella-zoster virus (VZV) infection, and have observed that vesicular cells are filled with >100 autophagosomes that are easily detectable after immunolabeling for the LC3 protein. To confirm our hypothesis that increased autophagosome formation was not secondary to a block, we examined all conditions of VZV infection as well as carrying out two assessments of autophagic flux. We first investigated autophagy in human skin xenografts in the severe combined immunodeficiency (SCID) mouse model of VZV pathogenesis, and observed that autophagosomes were abundant in infected human skin tissues. We next investigated autophagy following infection with sonically prepared cell-free virus in cultured cells. Under these conditions, autophagy was detected in a majority of infected cells, but was much less than that seen after an infected-cell inoculum. In other words, inoculation with lower-titered cell-free virus did not reflect the level of stress to the VZV-infected cell that was seen after inoculation of human skin in the SCID mouse model or monolayers with higher-titered infected cells. Finally, we investigated VZV-induced autophagic flux by two different methods (radiolabeling proteins and a dual-colored LC3 plasmid); both showed no evidence of a block in autophagy. Overall, therefore, autophagy within a VZV-infected cell was remarkably different from autophagy within an HSV-infected cell, whose genome contains two modifiers of autophagy, ICP34.5 and US11, not present in VZV. PMID:25535384

  5. Suppression of human immunodeficiency virus replication by ascorbate in chronically and acutely infected cells.

    PubMed Central

    Harakeh, S; Jariwalla, R J; Pauling, L

    1990-01-01

    We have studied the action of ascorbate (vitamin C) on human immunodeficiency virus type 1 (HIV-1), the etiological agent clinically associated with AIDS. We report the suppression of virus production and cell fusion in HIV-infected T-lymphocytic cell lines grown in the presence of nontoxic concentrations of ascorbate. In chronically infected cells expressing HIV at peak levels, ascorbate reduced the levels of extracellular reverse transcriptase (RT) activity (by greater than 99%) and of p24 antigen (by 90%) in the culture supernatant. Under similar conditions, no detectable inhibitory effects on cell viability, host metabolic activity, and protein synthesis were observed. In freshly infected CD4+ cells, ascorbate inhibited the formation of giant-cell syncytia (by approximately 93%). Exposure of cell-free virus to ascorbate at 37 degrees C for 1 day had no effect on its RT activity or syncytium-forming ability. Prolonged exposure of virus (37 degrees C for 4 days) in the presence of ascorbate (100-150 micrograms/ml) resulted in the drop by a factor of 3-14 in RT activity as compared to a reduction by a factor of 25-172 in extracellular RT released from chronically infected cells. These results indicate that ascorbate mediates an anti-HIV effect by diminishing viral protein production in infected cells and RT stability in extracellular virions. Images PMID:1698293

  6. Hepatitis B virus infection and pregnancy.

    PubMed

    Pol, Stanislas; Corouge, Marion; Fontaine, Hlne

    2011-10-01

    Pregnancy only mildly affects that natural progression of acute and chronic infection by the hepatitis B virus (HBV) but it does bring to light three important questions. Mother to child (vertical) transmission risk is best prevented by mandatory HBs antigen testing in all pregnant women in their second trimester and by systemic serovaccination of newborns of infected mothers. In mothers with high viral load, vertical infection in utero could be prevented by lamivudine, telbivudine or tenofovir treatment. Invasive obstetric or gynecological procedures (such as amniocentesis, forceps, etc.) do not seem to increase the risk of vertical infection. Breastfeeding is not contraindicated in maternal HBV infection after serovaccination of the newborn. This holds true for mothers on active treatment with tenofovir which is not absorbed into breast milk. When it comes to managing active antiviral treatment, in absence of virosuppression with lamivudine, tenofovir remains a logical step-up treatment; in absence of virosuppression with adefovir, tenofovir also remains a logical step-up choice as do tenofovir/emtricitabine combinations or lamivudine in absence of preexisting resistance which may have been induced during combination treatment of adefovir and lamivudine. In cases of effective virosuppression with treatment by analogues, lamivudine should be continued and entecavir should eventually be replaced by lamivudine, telbivudine or tenofovir; adefovir should be replaced by tenofovir or lamivudine in absence of resistance (which would require tenofovir therapy) or adefovir which would restrict lamivudine therapy. PMID:21659015

  7. 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

  8. Ultrastructural Characterization of the Giant Volcano-like Virus Factory of Acanthamoeba polyphaga Mimivirus

    PubMed Central

    Suzan-Monti, Marie; Scola, Bernard La; Barrassi, Lina; Espinosa, Leon; Raoult, Didier

    2007-01-01

    Acanthamoeba polyphaga Mimivirus is a giant double-stranded DNA virus defining a new genus, the Mimiviridae, among the Nucleo-Cytoplasmic Large DNA Viruses (NCLDV). We used utrastructural studies to shed light on the different steps of the Mimivirus replication cycle: entry via phagocytosis, release of viral DNA into the cell cytoplasm through fusion of viral and vacuolar membranes, and finally viral morphogenesis in an extraordinary giant cytoplasmic virus factory (VF). Fluorescent staining of the AT-rich Mimivirus DNA showed that it enters the host nucleus prior to the generation of a cytoplasmic independent replication centre that forms the core of the VF. Assembly and filling of viral capsids were observed within the replication centre, before release into the cell cytoplasm where progeny virions accumulated. 3D reconstruction from fluorescent and differential contrast interference images revealed the VF emerging from the cell surface as a volcano-like structure. Its size dramatically grew during the 24 h infectious lytic cycle. Our results showed that Mimivirus replication is an extremely efficient process that results from a rapid takeover of cellular machinery, and takes place in a unique and autonomous giant assembly centre, leading to the release of a large number of complex virions through amoebal lysis. PMID:17389919

  9. Ultrastructural characterization of the giant volcano-like virus factory of Acanthamoeba polyphaga Mimivirus.

    PubMed

    Suzan-Monti, Marie; La Scola, Bernard; Barrassi, Lina; Espinosa, Leon; Raoult, Didier

    2007-01-01

    Acanthamoeba polyphaga Mimivirus is a giant double-stranded DNA virus defining a new genus, the Mimiviridae, among the Nucleo-Cytoplasmic Large DNA Viruses (NCLDV). We used utrastructural studies to shed light on the different steps of the Mimivirus replication cycle: entry via phagocytosis, release of viral DNA into the cell cytoplasm through fusion of viral and vacuolar membranes, and finally viral morphogenesis in an extraordinary giant cytoplasmic virus factory (VF). Fluorescent staining of the AT-rich Mimivirus DNA showed that it enters the host nucleus prior to the generation of a cytoplasmic independent replication centre that forms the core of the VF. Assembly and filling of viral capsids were observed within the replication centre, before release into the cell cytoplasm where progeny virions accumulated. 3D reconstruction from fluorescent and differential contrast interference images revealed the VF emerging from the cell surface as a volcano-like structure. Its size dramatically grew during the 24 h infectious lytic cycle. Our results showed that Mimivirus replication is an extremely efficient process that results from a rapid takeover of cellular machinery, and takes place in a unique and autonomous giant assembly centre, leading to the release of a large number of complex virions through amoebal lysis. PMID:17389919

  10. Enteric Virus Infections and Diarrhea in Healthy and Human Immunodeficiency Virus-Infected Children

    PubMed Central

    Liste, Mary B.; Natera, Ivelisse; Suarez, Jos A.; Pujol, Flor H.; Liprandi, Ferdinando; Ludert, Juan E.

    2000-01-01

    Forty-three stool samples from 27 human immunodeficiency virus (HIV)-seropositive children and 38 samples from 38 HIV-negative children, collected during a 15-month period, were examined for enteric viruses. Diagnostic assays included enzyme immunoassays for rotavirus, adenovirus, and Norwalk virus; polyacrylamide gel electrophoresis for picobirnavirus and atypical rotavirus; and PCR for astrovirus and enterovirus. Specimens from HIV-positive children were more likely than those of HIV-negative children to have enterovirus (56 versus 21%; P < 0.0002) and astrovirus (12 versus 0%; P < 0.02), but not rotavirus (5 versus 8%; P > 0.5). No adenoviruses, picobirnaviruses, or Norwalk viruses were found. The rates of virus-associated diarrhea were similar among HIV-positive and HIV-negative children. Enteroviruses were excreted for up to 6 months in HIV-positive children; however, no evidence for prolonged excretion of poliovirus vaccine was observed. These results suggest that although infection with enterovirus and astrovirus may be frequent in HIV-infected children, enteric viruses are not associated with the diarrhea frequently suffered by these children. PMID:10921942

  11. The ecology of viruses that infect eukaryotic algae.

    PubMed

    Short, Steven M

    2012-09-01

    Because viruses of eukaryotic algae are incredibly diverse, sweeping generalizations about their ecology are rare. These obligate parasites infect a range of algae and their diversity can be illustrated by considering that isolates range from small particles with ssRNA genomes to much larger particles with 560?kb dsDNA genomes. Molecular research has also provided clues about the extent of their diversity especially considering that genetic signatures of algal viruses in the environment rarely match cultivated viruses. One general concept in algal virus ecology that has emerged is that algal viruses are very host specific and most infect only certain strains of their hosts; with the exception of viruses of brown algae, evidence for interspecies infectivity is lacking. Although some host-virus systems behave with boom-bust oscillations, complex patterns of intraspecies infectivity can lead to host-virus coexistence obfuscating the role of viruses in host population dynamics. Within the framework of population dynamics, host density dependence is an important phenomenon that influences virus abundances in nature. Variable burst sizes of different viruses also influence their abundances and permit speculations about different life strategies, but as exceptions are common in algal virus ecology, life strategy generalizations may not be broadly applicable. Gaps in knowledge of virus seasonality and persistence are beginning to close and investigations of environmental reservoirs and virus resilience may answer questions about virus inter-annual recurrences. Studies of algal mortality have shown that viruses are often important agents of mortality reinforcing notions about their ecological relevance, while observations of the surprising ways viruses interact with their hosts highlight the immaturity of our understanding. Considering that just two decades ago algal viruses were hardly acknowledged, recent progress affords the optimistic perspective that future studies will provide keys to unlocking our understanding of algal virus ecology specifically, and aquatic ecosystems generally. PMID:22360532

  12. 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 (36months). 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 3months, one at 6months, and one at 12months. 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 36months 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 12months 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

  13. Hepatitis B virus infection in Indonesia.

    PubMed

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

    2015-10-14

    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

  14. 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

  15. 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

  16. Amoebae as Battlefields for Bacteria, Giant Viruses, and Virophages

    PubMed Central

    Slimani, Meriem; Pagnier, Isabelle; Raoult, Didier

    2013-01-01

    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

  17. Arthritis after infection with Chikungunya virus.

    PubMed

    Ali Ou Alla, Sanae; Combe, Bernard

    2011-06-01

    Chikungunya virus (CHIKV) is an emerging alphavirus responsible for several infectious outbreaks in the world. After an acute stage of illness characterised by a fever-arthralgia syndrome and rash, joint disorders due to CHIKV infection can sometimes persist for several months or years. Chronic arthritis after this emerging disease is well documented, and similarities to rheumatoid arthritis have been described. Knowledge of the geographical epidemiology of CHIKV infection is crucial for better control of the disease. Thus, recent outbreaks have led to several studies, which have highlighted the need for a better understanding of the clinical features of Chikungunya (CHIK) and beginning knowledge of the pathophysiogenesis, which can lead to further research. PMID:22100284

  18. Hepatitis C virus infection in the human immunodeficiency virus infected patient.

    PubMed

    Clausen, Louise Nygaard; Lundbo, Lene Fogt; Benfield, Thomas

    2014-09-14

    Human immunodeficiency virus (HIV) and hepatitis C virus (HCV) share the same transmission routes; therefore, coinfection is frequent. An estimated 5-10 million individuals alone in the western world are infected with both viruses. The majority of people acquire HCV by injection drug use and, to a lesser extent, through blood transfusion and blood products. Recently, there has been an increase in HCV infections among men who have sex with men. In the context of effective antiretroviral treatment, liver-related deaths are now more common than Acquired Immune Deficiency Syndrome-related deaths among HIV-HCV coinfected individuals. Morbidity and mortality rates from chronic HCV infection will increase because the infection incidence peaked in the mid-1980s and because liver disease progresses slowly and is clinically silent to cirrhosis and end-stage-liver disease over a 15-20 year time period for 15%-20% of chronically infected individuals. HCV treatment has rapidly changed with the development of new direct-acting antiviral agents; therefore, cure rates have greatly improved because the new treatment regimens target different parts of the HCV life cycle. In this review, we focus on the epidemiology, diagnosis and the natural course of HCV as well as current and future strategies for HCV therapy in the context of HIV-HCV coinfection in the western world. PMID:25232248

  19. Hepatitis C Virus Infection and Mixed Cryoglobulinemia

    PubMed Central

    Lauletta, Gianfranco; Russi, Sabino; Conteduca, Vincenza; Sansonno, Loredana

    2012-01-01

    Hepatitis C virus (HCV) chronic infection is recognized as the major cause of mixed cryoglobulinemia (MC). Its persistence represents a continuous stimulus for host immune system with production of circulating immune complexes (ICs), one-third of them with cryoprecipitate property. Several factors contribute to the biological activities of ICs, many of which are not completely known. Among them, complement factors play a crucial role in the cold-insoluble ICs-mediated vasculitis, involving primarily small blood vessels in different tissues including skin, kidney, peripheral, and central nervous system. Liver represents the major target of HCV infection with inflammatory infiltrates, resembling secondary lymphoid follicles. Cytokine like CXCL13 contribute to B-cell homing in intraportal lymphoid aggregates, in which B-cell clonal selection may arise. B-cell clonal expansion starts as an antigen-driven event and expands towards indolent and malignant B-cell proliferation. Occurrence of intrahepatic B-cell clonalities correlates with extrahepatic clinical manifestations of HCV infection. In this context, cryoglobulinemic patients should be considered a peculiar HCV-infected population that needs a clinical multidisciplinary approach and more articulated therapeutic measures. PMID:22844322

  20. Peptide inhibitors against dengue virus infection.

    PubMed

    Panya, Aussara; Bangphoomi, Kunan; Choowongkomon, Kiattawee; Yenchitsomanus, Pa-Thai

    2014-08-01

    Dengue virus (DENV) infection has become a public health problem worldwide. The development of anti-DENV drug is urgently needed because neither licensed vaccine nor specific drug is currently available. Inhibition of DENV attachment and entry to host cells by blocking DENV envelope (E) protein is an attractive strategy for anti-DENV drug development. A hydrophobic pocket on the DENV E protein is essential for structural transition in the membrane fusion, and inhibition of this process is able to inhibit DENV infection. To search for a safe anti-DENV drug, we identified short peptides targeting the hydrophobic pocket by molecular docking. In addition, the information of predicted ligand-binding site of reported active compounds of DENV2 hydrophobic pocket was also used for peptide inhibitors selection. The di-peptide, EF, was the most effective on DENV2 infection inhibition in vitro with a half maximal inhibition concentration (IC50) of 96?m. Treatment of DENV2 with EF at the concentration of 200?m resulted in 83.47% and 84.15% reduction in viral genome and intracellular E protein, respectively. Among four DENV serotypes, DENV2 was the most effective for the inhibition. Our results provide the proof of concept for the development of therapeutic peptide inhibitors against DENV infection by the computer-aided molecular design. PMID:24612829

  1. 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

  2. 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

  3. 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

  4. 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/?l of viral RNA under monoplex conditions and 10 pg/?l 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

  5. Evidence that hepatitis C virus genome partly controls infection outcome

    PubMed Central

    Hartfield, Matthew; Bull, Rowena; White, Peter A; Lloyd, Andrew; Luciani, Fabio; Alizon, Samuel

    2014-01-01

    Infection by hepatitis C virus (HCV) leads to one of two outcomes; either the infection resolves within approximately 6 months or the virus can persist indefinitely. Host genetics are known to affect the likelihood of clearance or persistence. By contrast, the importance of the virus genotype in determining infection outcome is unknown, as quantifying this effect traditionally requires well-characterized transmission networks, which are rare. Extending phylogenetic approaches previously developed to estimate the virus control over set-point viral load in HIV-1 infections, we simulate inheritance of a binary trait along a phylogenetic tree, use this data to quantify how infection outcomes cluster and ascertain the effect of virus genotype on these. We apply our method to the Hepatitis C Incidence and Transmission Study in prisons (HITS-p) data set from Australia, as this cohort prospectively identified incident cases including viraemic subjects who ultimately clear the virus, thus providing us with a unique collection of sequences from clearing infections. We detect significant correlations between infection outcome and virus distance in the phylogeny for viruses of Genotype 1, with estimates lying at around 67%. No statistically significant estimates were obtained for viruses of Genotype 3a. PMID:24944567

  6. ENHANCED AND PROLONGED PULMONARY INFLUENZA VIRUS INFECTION FOLLOWING PHOSGENE INHALATION

    EPA Science Inventory

    Animal infectivity models have been important in the demonstration of enhanced susceptibility to viral and bacterial infection as a result of low level toxicant exposure. his study demonstrated an enhanced and prolonged viral infection using an influenza virus infectivity model i...

  7. 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 ...

  8. 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) ...

  9. Zika virus infection acquired during brief travel to Indonesia.

    PubMed

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

    2013-09-01

    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

  10. Mayaro virus infection, Amazon Basin region, Peru, 2010-2013.

    PubMed

    Halsey, Eric S; Siles, Crystyan; Guevara, Carolina; Vilcarromero, Stalin; Jhonston, Erik J; Ramal, Cesar; Aguilar, Patricia V; Ampuero, Julia S

    2013-11-01

    During 2010-2013, we recruited 16 persons with confirmed Mayaro virus infection in the Peruvian Amazon to prospectively follow clinical symptoms and serologic response over a 12-month period. Mayaro virus infection caused long-term arthralgia in more than half, similar to reports of other arthritogenic alphaviruses. PMID:24210165

  11. Mayaro Virus Infection, Amazon Basin Region, Peru, 20102013

    PubMed Central

    Siles, Crystyan; Guevara, Carolina; Vilcarromero, Stalin; Jhonston, Erik J.; Ramal, Cesar; Aguilar, Patricia V.; Ampuero, Julia S.

    2013-01-01

    During 20102013, we recruited 16 persons with confirmed Mayaro virus infection in the Peruvian Amazon to prospectively follow clinical symptoms and serologic response over a 12-month period. Mayaro virus infection caused long-term arthralgia in more than half, similar to reports of other arthritogenic alphaviruses. PMID:24210165

  12. 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

  13. 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

  14. 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

  15. Zika virus infection spread through saliva - a truth or myth?

    PubMed

    Siqueira, Walter Luiz; Moffa, Eduardo Buozi; Mussi, Maria Carolina Martins; Machado, Maria Aparecida de Andrade Moreira

    2016-01-01

    In this Point-of-view article we highlighted some features related to saliva and virus infection, in special for zika virus. In addition, we pointed out the potential oral problems caused by a microcephaly originated by a zika virus infection. In the end the, we demonstrated the importance of a more comprehensive exploration of saliva and their components as a fluid for diagnostic and therapeutic approaches on oral and systemic diseases. PMID:26981761

  16. 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

  17. Virus-induced secondary bacterial infection: a concise review.

    PubMed

    Hendaus, Mohamed A; Jomha, Fatima A; Alhammadi, Ahmed H

    2015-01-01

    Respiratory diseases are a very common source of morbidity and mortality among children. Health care providers often face a dilemma when encountering a febrile infant or child with respiratory tract infection. The reason expressed by many clinicians is the trouble to confirm whether the fever is caused by a virus or a bacterium. The aim of this review is to update the current evidence on the virus-induced bacterial infection. We present several clinical as well in vitro studies that support the correlation between virus and secondary bacterial infections. In addition, we discuss the pathophysiology and prevention modes of the virus-bacterium coexistence. A search of the PubMed and MEDLINE databases was carried out for published articles covering bacterial infections associated with respiratory viruses. This review should provide clinicians with a comprehensive idea of the range of bacterial and viral coinfections or secondary infections that could present with viral respiratory illness. PMID:26345407

  18. 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...

  19. Human immunodeficiency virus can productively infect cultured human glial cells.

    PubMed Central

    Cheng-Mayer, C; Rutka, J T; Rosenblum, M L; McHugh, T; Stites, D P; Levy, J A

    1987-01-01

    Six isolates of the human immunodeficiency virus (HIV) showed differences in their ability to productively infect glioma-derived cell lines and early-passage human brain cell cultures. Susceptibility to HIV infection correlated well with the expression of the astrocyte marker glial fibrillary acidic protein. The CD4 molecule was expressed on some, but not all, of the brain-derived cells; however, no correlation was observed between CD4 protein expression and susceptibility to virus infection. The results show that HIV can productively infect human brain cells, particularly those of glial origin, and suggest that these cell types in the brain can harbor the virus. Images PMID:3472222

  20. Hepatitis C virus infection and glomerular disease.

    PubMed

    Fabrizi, F; Donato, F; Messa, P

    2014-06-01

    The association between hepatitis C virus (HCV) infection and chronic kidney disease (CKD) is well established and remains an area of intense research. HCV infection is associated with a large spectrum of histo-pathological lesions in both native and transplanted kidneys. The frequency of kidney damage in HCV-infected patients appears low even if is not fully detailed. The most frequent HCV-associated renal lesion is type I membrano-proliferative glomerulonephritis, usually in the context of type II mixed cryoglobulinemia. Various approaches have been tried for the treatment of HCV-related glomerulonephritis, including immunosuppressive therapy (corticosteroids and cytotoxic agents), plasma exchange and antiviral agents. Antiviral treatment of HCV-associated glomerulonephritis has shown encouraging results. Immunosuppressive therapy is particularly recommended for cryoglobulinemic kidney disease. Two distinct approaches should be considered for the treatment of HCV-associated cryoglobulinemic glomerulonephritis according to the level of proteinuria and kidney failure. Some evidence on rituximab therapy for HCV-related cryoglobulinemic glomerulonephritis exists but several questions related to its use need to be addressed. PMID:24988205

  1. Epidemiological and clinical evaluation of children with respiratory virus infections

    PubMed Central

    Shatizadeh, Somayeh; Yavarian, Jila; Rezaie, Farhad; Mahmoodi, Mahmood; Naseri, Maryam; Mokhtari Azad, Talat

    2014-01-01

    Background: Respiratory viruses are the leading cause of respiratory tract infections among children and are responsible for causing morbidity and mortality worldwide. This study was performed to detect viruses in children with respiratory infections and describe their epidemiology and clinical characteristics. Methods: In this descriptive cross sectional study, throat swabs and wash specimens from 202 children younger than six years of age with diagnosis of a respiratory tract infection from a total of 897 specimens were evaluated using multiplex PCR method. Results: Respiratory viruses were detected in 92 children: respiratory synsytial virus, 16.8%; influenza virus, 5.4%; parainfluenza virus, 8.4%; adenovirus, 14.4% and human metapneumo virus 0.49% with male predominance and higher distribution in children younger than 1 year of age with preference in the cold months of year. The clinical presentations of all detected viruses were almost similar. Conclusion: In the present study, nine different respiratory viruses were detected. RSV causes the great majority of respiratory virus infections in children. There was no significant difference in epidemiologic patterns of these viruses in comparison to other studies. PMID:25664303

  2. Facilitative and antagonistic interactions between plant viruses in mixed infections.

    PubMed

    Syller, Jerzy

    2012-02-01

    Mixed infections of plant viruses are common in nature, and a number of important virus diseases of plants are the outcomes of interactions between causative agents. Multiple infections lead to a variety of intrahost virus-virus interactions, many of which may result in the generation of variants showing novel genetic features, and thus change the genetic structure of the viral population. Hence, virus-virus interactions in plants may be of crucial significance for the understanding of viral pathogenesis and evolution, and consequently for the development of efficient and stable control strategies. The interactions between plant viruses in mixed infections are generally categorized as synergistic or antagonistic. Moreover, mixtures of synergistic and antagonistic interactions, creating usually unpredictable biological and epidemiological consequences, are likely to occur in plants. The mechanisms of some of these are still unknown. This review aims to bring together the current knowledge on the most commonly occurring facilitative and antagonistic interactions between related or unrelated viruses infecting the same host plant. The best characterized implications of these interactions for virus-vector-host relationships are included. The terms 'synergism' and 'helper dependence' for facilitative virus-virus interactions, and 'cross-protection' and 'mutual exclusion' for antagonistic interactions, are applied in this article. PMID:21726401

  3. Chikungunya Virus Infection during Pregnancy, Runion, France, 2006

    PubMed Central

    Rollot, Olivier; Grardin, Patrick; Gazre, Bernard-Alex; Bideault, Jacques; Lagarde, Louis; Dhuime, Barbara; Orvain, Eric; Cuillier, Fabrice; Ramful, Duksha; Sampriz, Sylvain; Jaffar-Bandjee, Marie-Christine; Michault, Alain; Cotte, Liliane; Kaminski, Monique; Fourmaintraux, Alain

    2010-01-01

    Mother-to-child transmission of chikungunya virus was reported during the 20052006 outbreak on Runion Island, France. To determine the effects of this virus on pregnancy outcomes, we conducted a study of pregnant women in Runion in 2006. The study population was composed of 1,400 pregnant women (628 uninfected, 658 infected during pregnancy, 27 infected before pregnancy, and 87 infected on unknown dates). We compared pregnancy outcomes for 655 (628 + 27) women not infected during pregnancy with 658 who were infected during pregnancy. Infection occurred during the first trimester for 15% of the infected women, the second for 59%, and the third for 26%. Only hospital admission during pregnancy differed between infected and uninfected women (40% vs. 29%). Other outcomes (cesarean deliveries, obstetric hemorrhaging, preterm births, stillbirths after 22 weeks, birthweight, congenital malformations, and newborn admissions) were similar. This virus had no observable effect on pregnancy outcomes. PMID:20202416

  4. Experimental simian varicella virus infection of St. Kitts vervet monkeys.

    PubMed

    Gray, W L; Williams, R J; Chang, R; Soike, K F

    1998-08-01

    Experimental simian varicella virus (SVV) infection of St. Kitts vervet monkeys was evaluated as an animal model to investigate human varicella-zoster virus (VZV) infections. During the incubation period, viremia disseminated infectious virus throughout the body via infected peripheral blood lymphocytes (PBLs). A vesicular skin rash in the inguinal area, and on the abdomen, extremities, and face appeared on day 7-10 postinfection. Necrosis and hemorrhage in lung and liver tissues from acutely infected monkeys were evident upon histologic analysis. Recovery from simian varicella was accompanied by a rise in the serum neutralizing antibody response to the virus. SVV latency was established in trigeminal ganglia of monkeys which resolved the acute infection. This study indicates that experimental SVV infection of St. Kitts vervets is a useful animal model to investigate SVV and VZV pathogenesis and to evaluate potential antiviral agents and vaccines. PMID:9879858

  5. Suramin inhibits in vitro infection by duck hepatitis B virus, Rous sarcoma virus, and hepatitis delta virus.

    PubMed

    Petcu, D J; Aldrich, C E; Coates, L; Taylor, J M; Mason, W S

    1988-12-01

    Suramin blocked in vitro infection by duck hepatitis B virus, a hepadnavirus, and Rous sarcoma virus, a retrovirus. Although suramin was able to inhibit the virus-encoded reverse transcriptase activities of these two viruses, this inhibition did not appear to account for the anti-viral effect of the drug. In particular, suramin was unable to block synthesis within cells of full-length viral DNAs when added subsequent to infection. The results are consistent with the hypothesis that suramin acted by blocking virus uptake or uncoating. As further support of this hypothesis, we found that suramin also blocked infection by hepatitis delta virus, an RNA virus that is not known to employ reverse transcriptase during the initiation of infection. PMID:2462306

  6. Animal models of respiratory syncytial virus infection.

    PubMed

    Byrd, L G; Prince, G A

    1997-12-01

    Over the past two decades, animal models of respiratory syncytial virus (RSV) infection have been developed using primates, cotton rats, mice, calves, guinea pigs, ferrets, and hamsters. Use of these models has shed light on the mechanisms of vaccine-enhanced disease seen in clinical trials of a formalin-inactivated RSV vaccine and has provided a means for testing efficacy and safety of candidate prophylactic and therapeutic strategies. The development of multiple animal models has coincided with the realization that RSV disease in humans is a multifaceted disease whose clinical manifestations and sequelae depend upon age, genetic makeup, immunologic status, and concurrent disease within subpopulations. There is no single human subpopulation in whom all forms of RSV disease manifest, nor is there a single animal model that duplicates all forms of RSV disease. The choice of an experimental model will be governed by the specific manifestation of disease to be studied. PMID:9431379

  7. 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

  8. 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

  9. 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

  10. Neonatal herpes simplex virus infection: epidemiology and treatment.

    PubMed

    James, Scott H; Kimberlin, David W

    2015-03-01

    Herpes simplex virus types 1 (HSV-1) and 2 (HSV-2) are highly prevalent viruses capable of establishing lifelong infection. Genital herpes in women of childbearing age represents a major risk for mother-to-child transmission (MTCT) of HSV infection, with primary and first-episode genital HSV infections posing the highest risk. The advent of antiviral therapy with parenteral acyclovir has led to significant improvement in neonatal HSV disease mortality. Further studies are needed to improve the clinician's ability to identify infants at increased risk for HSV infection and prevent MTCT, and to develop novel antiviral agents with increased efficacy in infants with HSV infection. PMID:25677996

  11. HIGH VIRUS TITER IN FEATHER PULP OF CHICKENS INFECTED WITH SUBGROUP J AVIAN LEUKOSIS VIRUS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Subgroup J avian leukosis viruses (ALVs), which are a recombinant virus between exogenous and endogenous ALVs, can spread by either vertical or horizontal transmission. Exogenous and endogenous ALVs, can be detected in feather pulp. In this study, virus titers in feather pulp of chickens infected w...

  12. Giant viruses coexisted with the cellular ancestors and represent a distinct supergroup along with superkingdoms Archaea, Bacteria and Eukarya

    PubMed Central

    2012-01-01

    Background The discovery of giant viruses with genome and physical size comparable to cellular organisms, remnants of protein translation machinery and virus-specific parasites (virophages) have raised intriguing questions about their origin. Evidence advocates for their inclusion into global phylogenomic studies and their consideration as a distinct and ancient form of life. Results Here we reconstruct phylogenies describing the evolution of proteomes and protein domain structures of cellular organisms and double-stranded DNA viruses with medium-to-very-large proteomes (giant viruses). Trees of proteomes define viruses as a ‘fourth supergroup’ along with superkingdoms Archaea, Bacteria, and Eukarya. Trees of domains indicate they have evolved via massive and primordial reductive evolutionary processes. The distribution of domain structures suggests giant viruses harbor a significant number of protein domains including those with no cellular representation. The genomic and structural diversity embedded in the viral proteomes is comparable to the cellular proteomes of organisms with parasitic lifestyles. Since viral domains are widespread among cellular species, we propose that viruses mediate gene transfer between cells and crucially enhance biodiversity. Conclusions Results call for a change in the way viruses are perceived. They likely represent a distinct form of life that either predated or coexisted with the last universal common ancestor (LUCA) and constitute a very crucial part of our planet’s biosphere. PMID:22920653

  13. Genetic Strategy to Prevent Influenza Virus Infections in Animals

    PubMed Central

    Chen, Jianzhu; Chen, Steve C.-Y.; Stern, Patrick; Scott, Benjamin B.; Lois, Carlos

    2009-01-01

    The natural reservoirs of influenza viruses are aquatic birds. After adaptation, avian viruses can acquire the ability to infect humans and cause severe disease. Because domestic poultry serves as a key link between the natural reservoir of influenza viruses and epidemics and pandemics in human populations, an effective measure to control influenza would be to eliminate or reduce influenza virus infection in domestic poultry. The development and distribution of influenza-resistant poultry represents a proactive strategy for controlling the origin of influenza epidemics and pandemics in both poultry and human populations. Recent developments in RNA interference and transgenesis in birds should facilitate the development of influenza-resistant poultry. PMID:18269324

  14. Human immunodeficiency virus infection in pregnancy

    PubMed Central

    Arikan, Yasemin; Burdge, David R

    1998-01-01

    The incidence and prevalence of human immunodeficiency virus (HIV) infection in women of child-bearing age continue to increase both internationally and in Canada. The care of HIV-infected pregnant women is complex, and multiple issues must be addressed, including the current and future health of the woman, minimization of the risk of maternal-infant HIV transmission, and maintenance of the well-being of the fetus and neonate. Vertical transmission of HIV can occur in utero, intrapartum and postpartum, but current evidence suggests that the majority of transmission occurs toward end of term, or during labour and delivery. Several maternal and obstetrical factors influence transmission rates, which can be reduced by optimal medical and obstetrical care. Zidovudine therapy has been demonstrated to reduce maternal-infant transmission significantly, but several issues, including the short and long term safety of antiretrovirals and the optimal use of combination antiretroviral therapy in pregnancy, remain to be defined. It is essential that health care workers providing care to these women fully understand the natural history of HIV disease in pregnancy, the factors that affect vertical transmission and the management issues during pregnancy. Close collaboration among a multidisciplinary team of knowledgeable health professionals and, most importantly, the woman herself can improve both maternal and infant outcomes. PMID:22346550

  15. Occult hepatitis B virus infection in Egypt

    PubMed Central

    Elbahrawy, Ashraf; Alaboudy, Alshimaa; El Moghazy, Walid; Elwassief, Ahmed; Alashker, Ahmed; Abdallah, Abdallah Mahmoud

    2015-01-01

    The emerging evidence of the potentially clinical importance of occult hepatitis B virus (HBV) infection (OBI) increases the interest in this topic. OBI may impact in several clinical contexts, which include the possible transmission of the infection, the contribution to liver disease progression, the development of hepatocellular carcinoma, and the risk of reactivation. There are several articles that have published on OBI in Egyptian populations. A review of MEDLINE database was undertaken for relevant articles to clarify the epidemiology of OBI in Egypt. HBV genotype D is the only detectable genotype among Egyptian OBI patients. Higher rates of OBI reported among Egyptian chronic HCV, hemodialysis, children with malignant disorders, and cryptogenic liver disease patients. There is an evidence of OBI reactivation after treatment with chemotherapy. The available data suggested that screening for OBI must be a routine practice in these groups of patients. Further studies needed for better understand of the epidemiology of OBI among Egyptian young generations after the era of hepatitis B vaccination. PMID:26140086

  16. 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

  17. Virus-induced secondary bacterial infection: a concise review

    PubMed Central

    Hendaus, Mohamed A; Jomha, Fatima A; Alhammadi, Ahmed H

    2015-01-01

    Respiratory diseases are a very common source of morbidity and mortality among children. Health care providers often face a dilemma when encountering a febrile infant or child with respiratory tract infection. The reason expressed by many clinicians is the trouble to confirm whether the fever is caused by a virus or a bacterium. The aim of this review is to update the current evidence on the virus-induced bacterial infection. We present several clinical as well in vitro studies that support the correlation between virus and secondary bacterial infections. In addition, we discuss the pathophysiology and prevention modes of the virus–bacterium coexistence. A search of the PubMed and MEDLINE databases was carried out for published articles covering bacterial infections associated with respiratory viruses. This review should provide clinicians with a comprehensive idea of the range of bacterial and viral coinfections or secondary infections that could present with viral respiratory illness. PMID:26345407

  18. Effects of influenza A virus infection on migrating mallard ducks

    PubMed Central

    Latorre-Margalef, Neus; Gunnarsson, Gunnar; Munster, Vincent J.; Fouchier, Ron A.M.; Osterhaus, Albert D.M.E.; Elmberg, Johan; Olsen, Björn; Wallensten, Anders; Haemig, Paul D.; Fransson, Thord; Brudin, Lars; Waldenström, Jonas

    2008-01-01

    The natural reservoir of influenza A virus is waterfowl, particularly dabbling ducks (genus Anas). Although it has long been assumed that waterfowl are asymptomatic carriers of the virus, a recent study found that low-pathogenic avian influenza (LPAI) infection in Bewick's swans (Cygnus columbianus bewickii) negatively affected stopover time, body mass and feeding behaviour. In the present study, we investigated whether LPAI infection incurred ecological or physiological costs to migratory mallards (Anas platyrhynchos) in terms of body mass loss and staging time, and whether such costs could influence the likelihood for long-distance dispersal of the avian influenza virus by individual ducks. During the autumn migrations of 2002–2007, we collected faecal samples (n=10 918) and biometric data from mallards captured and banded at Ottenby, a major staging site in a flyway connecting breeding and wintering areas of European waterfowl. Body mass was significantly lower in infected ducks than in uninfected ducks (mean difference almost 20 g over all groups), and the amount of virus shed by infected juveniles was negatively correlated with body mass. There was no general effect of infection on staging time, except for juveniles in September, in which birds that shed fewer viruses stayed shorter than birds that shed more viruses. LPAI infection did not affect speed or distance of subsequent migration. The data from recaptured individuals showed that the maximum duration of infection was on average 8.3 days (s.e. 0.5), with a mean minimum duration of virus shedding of only 3.1 days (s.e. 0.1). Shedding time decreased during the season, suggesting that mallards acquire transient immunity for LPAI infection. In conclusion, deteriorated body mass following infection was detected, but it remains to be seen whether this has more long-term fitness effects. The short virus shedding time suggests that individual mallards are less likely to spread the virus at continental or intercontinental scales. PMID:19129127

  19. Early Dengue Virus Infection in Human Skin: A Cycle of Inflammation and Infectivity.

    PubMed

    Ivory, Matthew O; Birchall, James C; Piguet, Vincent

    2015-07-01

    Early events during dengue virus (DENV) infection remain poorly understood. In this issue, Schaeffer and colleagues employ ex vivo human skin cells to investigate viral infection. They show that skin-resident immune cells are infected by DENV and that their infectability is increased in the inflammatory skin conditions (especially those in which IL-4 is released) that accompany the mosquito bites transmitting the virus. PMID:26066889

  20. Steroid-responsive, progressive, focal measles virus brain infection.

    PubMed

    Steiner, Israel; Livneh, Vered; Hoffmann, Chen; Nass, Dvora; Mor, Orna; Chapman, Joab

    2014-06-01

    Chronic measles virus infection of the brain causes subacute sclerosing panencephalitis (SSPE), a progressive, relentless fatal disorder. We report a 52-year-old male who developed focal, chronic persistent measles virus infection of the brain following interferon and ribavirin therapy for hepatitis C, and who responded to steroid therapy. This case, diametrically different from SSPE, has 2 unique features, its focal nature and its permissive response to steroids, that may add to the understanding of the pathogenesis of SSPE and the mechanism enabling viruses to evade the immune response and establish persistent brain infection. PMID:24817010

  1. Hepatitis C virus infection in hemodialysis patients.

    PubMed

    Vallet-Pichard, Anais; Pol, Stanislas

    2013-09-01

    Hepatitis C virus (HCV) infection is observed in around 20% of dialysis patients and in allograft recipients and results in a significant morbidity and mortality, especially after transplantation. Its prevalence has markedly decreased in patients who are candidates for transplantation since the introduction of screening, hygiene and prevention measures, including systematic screening of blood and organ donations, use of erythropoietin, and compliance with universal hygiene rules. A liver biopsy is preferable to non-invasive biochemical and/or morphological tests of fibrosis to evaluate liver fibrosis before and even after transplantation. In HCV-infected dialyzed patients who are not candidates for renal transplantation, the indication for antiviral therapy is limited to significant fibrosis (fibrosis ≥ 2 on the METAVIR scale). Antiviral treatment should be proposed to any HCV-infected candidate for renal transplantation, whatever the baseline histopathology. The recommendation is to use standard interferon-α as monotherapy, but pegylated interferon can be used, resulting in sustained virological response, while low doses of combined ribavirin may enhance the antiviral efficacy. After transplantation, interferon-α is contra-indicated but may be used in patients for whom the benefits of antiviral treatment clearly outweigh the risks, especially that of allograft rejection. All cirrhotic patients should be screened for hepatocellular carcinoma, whose risk is enhanced by immunosuppressive regimens. Sustained suppression of necro-inflammation may result in the reversal of cirrhosis, which reduces liver-related morbidity and improves patient and allograft survival. Finally, due to the high mortality after renal transplantation, active cirrhosis must be considered to be a contraindication to kidney transplantation, but an indication to combined liver-kidney transplantation; on the contrary, inactive compensated cirrhosis may permit renal transplantation alone. PMID:23933193

  2. JC Virus Antibody Status Underestimates Infection Rates

    PubMed Central

    Berger, Joseph R.; Houff, Sidney A.; Gurwell, Julie; Vega, Nubia; Miller, Craig S.; Danaher, Robert J.

    2013-01-01

    Background JC virus (JCV) seropositivity is a risk factor for progressive multifocal leukoencephalopathy (PML) in patients on natalizumab. Accordingly, the JCV serological antibody test is of paramount importance in determining disease risk. Methods We tested the accuracy of the JCV serum antibody test by comparing the results of JCV serology to JC viruria and viremia in 67 patients enrolled in a single-center, retrospective cohort study. Bodily fluids (urine and blood) were assessed for JCV DNA by real time quantitative polymerase chain reaction 6 to 47 months earlier (mean 26.1 months) before JCV antibody testing. In 10 individuals, blood and urine samples were obtained on two separate occasions at 6 month intervals. Results Forty (59.7%) of the 67 patients were JCV seropositive. Of 27 JCV seronegative patients, 10 (37%) had JC viruria. Urine JCV DNA copy numbers were significantly higher in the seropositive group (mean log copy number: 5.93; range 1.85 – 9.21) than the seronegative group (mean log copy number: 2.41; range 1.85 – 5.43) (p=0.0026). Considering all body fluid test results, 50 (74.6%) of the 67 patients were previously infected with JCV. Conclusions The false negative rate of the JCV serology in this study was 37%; therefore, JCV serostatus does not appear to identify all patients infected with JCV. Thus, a negative JCV antibody result should not be conflated with absence of JCV infection. This discordance may be important in understanding JCV biology, risk for PML and PML pathogenesis. PMID:23526716

  3. Reference gene selection for quantitative real-time PCR analysis in virus infected cells: SARS corona virus, Yellow fever virus, Human Herpesvirus-6, Camelpox virus and Cytomegalovirus infections

    PubMed Central

    Radoni?, Aleksandar; Thulke, Stefanie; Bae, Hi-Gung; Mller, Marcel A; Siegert, Wolfgang; Nitsche, Andreas

    2005-01-01

    Ten potential reference genes were compared for their use in experiments investigating cellular mRNA expression of virus infected cells. Human cell lines were infected with Cytomegalovirus, Human Herpesvirus-6, Camelpox virus, SARS coronavirus or Yellow fever virus. The expression levels of these genes and the viral replication were determined by real-time PCR. Genes were ranked by the BestKeeper tool, the GeNorm tool and by criteria we reported previously. Ranking lists of the genes tested were tool dependent. However, over all, ?-actin is an unsuitable as reference gene, whereas TATA-Box binding protein and peptidyl-prolyl-isomerase A are stable reference genes for expression studies in virus infected cells. PMID:15705200

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

    PubMed Central

    Priet, Stphane; Lartigue, Audrey; Debart, Franoise; 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

  5. 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

  6. 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…

  7. Detection, pathogenesis, and therapy of respiratory syncytial virus infections.

    PubMed Central

    Welliver, R C

    1988-01-01

    Respiratory syncytial virus (RSV) infection is a major cause of serious lower respiratory disease in infancy and early childhood. The unique pathogenesis of lower respiratory illness due to RSV offers some intriguing clues to the role of the human immune system in both protection against and development of respiratory illness. More than any other virus, rapid diagnostic techniques have been especially successful in identifying RSV infection. Many of these techniques could be easily adaptable to diagnosis of influenza virus infection and other agents. Finally, ribavirin therapy of RSV infection represents one of the few instances in which antiviral therapy has been shown to be effective for respiratory illnesses. Fundamental observations in these areas in the case of RSV infection open up new and exciting pathways for investigation of respiratory infection due to other viral, chlamydial, and mycoplasmal agents. PMID:3060243

  8. Innate immune cell networking in hepatitis C virus infection.

    PubMed

    Saha, Banishree; Szabo, Gyongyi

    2014-11-01

    Persistent viral infection, such as HCV infection, is the result of the inability of the host immune system to mount a successful antiviral response, as well as the escape strategies devised by the virus. Although each individual component of the host immune system plays important roles in antiviral immunity, the interactive network of immune cells as a whole acts against the virus. The innate immune system forms the first line of host defense against viral infection, and thus, virus elimination or chronic HCV infection is linked to the direct outcome of the interactions between the various innate immune cells and HCV. By understanding how the distinct components of the innate immune system function both individually and collectively during HCV infection, potential therapeutic targets can be identified to overcome immune dysfunction and control chronic viral infection. PMID:25001860

  9. 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

  10. Fibromyalgia-associated hepatitis C virus infection.

    PubMed

    Rivera, J; de Diego, A; Trinchet, M; Garca Monforte, A

    1997-09-01

    The objective was to determine whether there might be an association between hepatitis C virus (HCV) chronic infection and fibromyalgia (FM). We determined the prevalence of HCV infection in 112 FM patients, in comparison with matched rheumatoid arthritis (RA) patients from the out-patient clinic of a teaching tertiary care general hospital. Furthermore, we looked for evidence of FM in 58 patients diagnosed with chronic hepatitis due to HCV, compared with matched surgery clinic patients, HCV antibodies were determined by enzyme-linked immunosorbent assay (ELISA) and recombinant immunoblot assay (RIBA). Serum RNA of HCV (HCV-RNA) was determined by polymerase chain reaction. In the group of FM patients, HCV antibodies were found by ELISA in 17 (15.2%) patients and in six (5.3%) of the RA controls (P < 0.05). RIBA was positive in 16 and indeterminate in one of the FM patients. Serum HCV-RNA was found in 13 of these FM patients. In eight (47%) FM patients, alanine aminotransferase (ALT) was normal, although HCV-RNA was detected in four (50%) of them. In the group of patients with chronic hepatitis due to HCV, all patients had HCV antibodies and the presence of HCV-RNA in serum. Within these patients, 31 (53%) had diffuse musculoskeletal pain, while six (10%) fulfilled FM diagnostic criteria. In the control group, 13/58 (22%) had diffuse musculoskeletal pain (P < 0.001), whereas only one female patient (1.7%) fulfilled FM criteria (P < 0.05). Serum ALT was 51.7 +/- 38.4 in FM patients, whereas it was 122 +/- 76.3 in patients with HCV chronic hepatitis but without FM (P < 0.001). There were no statistical differences in autoimmune markers between patients with and without FM. These data suggest that there exists an association between FM and active HCV infection in some of our patients. FM is not associated with liver damage or autoimmune markers in these patients. HCV infection should be considered in FM patients even though ALT elevations were absent. PMID:9376995

  11. Maternal Effects of Respiratory Syncytial Virus Infection during Pregnancy.

    PubMed

    Wheeler, Sarahn M; Dotters-Katz, Sarah; Heine, R Phillip; Grotegut, Chad A; Swamy, Geeta K

    2015-11-01

    Given the illness and deaths caused by respiratory syncytial virus (RSV) infection during the first year of life, preventing infant RSV infections through maternal vaccination is intriguing. However, little is known about the extent and maternal effects of RSV infection during pregnancy. We describe 3 cases of maternal RSV infection diagnosed at a US center during winter 2014. Case-patient 1 (26 years old, week 33 of gestation) received a diagnosis of RSV infection and required mechanical ventilation. Case-patient 2 (27 years old, week 34 of gestation) received a diagnosis of infection with influenza A(H1N1) virus and RSV and required mechanical ventilation. Case-patient 3 (21 years old, week 32 of gestation) received a diagnosis of group A streptococcus pharyngitis and RSV infection and was monitored as an outpatient. Clarifying the effects of maternal RSV infection could yield valuable insights into potential maternal and fetal benefits of an effective RSV vaccination program. PMID:26485575

  12. Maternal Effects of Respiratory Syncytial Virus Infection during Pregnancy

    PubMed Central

    Wheeler, Sarahn M.; Dotters-Katz, Sarah; Heine, R. Phillip; Grotegut, Chad A.

    2015-01-01

    Given the illness and deaths caused by respiratory syncytial virus (RSV) infection during the first year of life, preventing infant RSV infections through maternal vaccination is intriguing. However, little is known about the extent and maternal effects of RSV infection during pregnancy. We describe 3 cases of maternal RSV infection diagnosed at a US center during winter 2014. Case-patient 1 (26 years old, week 33 of gestation) received a diagnosis of RSV infection and required mechanical ventilation. Case-patient 2 (27 years old, week 34 of gestation) received a diagnosis of infection with influenza A(H1N1) virus and RSV and required mechanical ventilation. Case-patient 3 (21 years old, week 32 of gestation) received a diagnosis of group A streptococcus pharyngitis and RSV infection and was monitored as an outpatient. Clarifying the effects of maternal RSV infection could yield valuable insights into potential maternal and fetal benefits of an effective RSV vaccination program. PMID:26485575

  13. 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

  14. 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

  15. The Impact of Wolbachia on Virus Infection in Mosquitoes.

    PubMed

    Johnson, Karyn N

    2015-11-01

    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

  16. Immune response and tolerance during chronic hepatitis B virus infection.

    PubMed

    Bertoletti, Antonio; Gehring, Adam

    2007-10-01

    The hepatitis B virus (HBV) is a hepatotropic non-cytopathic DNA virus that despite the presence of an effective prophylactic vaccine is estimated to infect 300 million people, with a particularly high prevalence in Asia and Africa. It causes liver diseases that vary greatly in severity from person to person. Some subjects control infection efficiently and clear the virus from the bloodstream either without clinically evident liver disease or with an acute inflammation of the liver (acute hepatitis) that can resolve without long-term clinical sequelae. Other patients fail to clear the virus and develop chronic infection. Most chronically infected patients remain asymptomatic without life-threatening liver disease but 10-30% develop liver cirrhosis with possible progression to liver cancer. Outcome of infection and the pathogenesis of liver disease are determined by virus and host factors, which have been difficult tofully elucidate because the host range of HBV is limited to man and chimpanzees. However, the study of animal models of related Hepadnavirus infections and transgenic mouse able to express individual HBV genes or replicate the entire viral genome have clarified several aspects connected to HBV infection. Furthermore, the ability to analyze many immunological phenomena ex vivo through direct quantification of Ag-specific T cells in humans and chimps has considerably increased our knowledge of HBV pathogenesis. Here, we will discuss the distinctions of HBV adaptive immunity between resolved and persistently infected patients and the host/viral factors that can cause and maintain them. PMID:17931183

  17. 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 ...

  18. 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...

  19. 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...

  20. Experimental sialodacryoadenitis virus infection in severe combined immunodeficient mice.

    PubMed Central

    Percy, D H; Williams, K L; Croy, B A

    1991-01-01

    Mice with a severe combined immunodeficiency in B and T lymphocytes and natural killer cells (SCID-beige) were inoculated intranasally with sialodacryoadenitis (SDA) virus, a coronavirus of rats. Animals were killed at designated intervals and tissues were examined for evidence of viral infection by light microscopy and immunofluorescence microscopy. Based on these criteria, there was no evidence that these immunodeficient mice were susceptible to infection with SDA virus. PMID:1653101

  1. Easy and Rapid Detection of Mumps Virus by Live Fluorescent Visualization of Virus-Infected Cells.

    PubMed

    Takahashi, Tadanobu; Agarikuchi, Takashi; Kurebayashi, Yuuki; Shibahara, Nona; Suzuki, Chihiro; Kishikawa, Akiko; Fukushima, Keijo; Takano, Maiko; Suzuki, Fumie; Wada, Hirohisa; Otsubo, Tadamune; Ikeda, Kiyoshi; Minami, Akira; Suzuki, Takashi

    2015-01-01

    Mumps viruses show diverse cytopathic effects (CPEs) of infected cells and viral plaque formation (no CPE or no plaque formation in some cases) depending on the viral strain, highlighting the difficulty in mumps laboratory studies. In our previous study, a new sialidase substrate, 2-(benzothiazol-2-yl)-4-bromophenyl 5-acetamido-3,5-dideoxy-?-D-glycero-D-galacto-2-nonulopyranosidonic acid (BTP3-Neu5Ac), was developed for visualization of sialidase activity. BTP3-Neu5Ac can easily and rapidly perform histochemical fluorescent visualization of influenza viruses and virus-infected cells without an antiviral antibody and cell fixation. In the present study, the potential utility of BTP3-Neu5Ac for rapid detection of mumps virus was demonstrated. BTP3-Neu5Ac could visualize dot-blotted mumps virus, virus-infected cells, and plaques (plaques should be called focuses due to staining of infected cells in this study), even if a CPE was not observed. Furthermore, virus cultivation was possible by direct pick-up from a fluorescent focus. In conventional methods, visible appearance of the CPE and focuses often requires more than 6 days after infection, but the new method with BTP3-Neu5Ac clearly visualized infected cells after 2 days and focuses after 4 days. The BTP3-Neu5Ac assay is a precise, easy, and rapid assay for confirmation and titration of mumps virus. PMID:26629699

  2. Easy and Rapid Detection of Mumps Virus by Live Fluorescent Visualization of Virus-Infected Cells

    PubMed Central

    Takahashi, Tadanobu; Agarikuchi, Takashi; Kurebayashi, Yuuki; Shibahara, Nona; Suzuki, Chihiro; Kishikawa, Akiko; Fukushima, Keijo; Takano, Maiko; Suzuki, Fumie; Wada, Hirohisa; Otsubo, Tadamune; Ikeda, Kiyoshi; Minami, Akira; Suzuki, Takashi

    2015-01-01

    Mumps viruses show diverse cytopathic effects (CPEs) of infected cells and viral plaque formation (no CPE or no plaque formation in some cases) depending on the viral strain, highlighting the difficulty in mumps laboratory studies. In our previous study, a new sialidase substrate, 2-(benzothiazol-2-yl)-4-bromophenyl 5-acetamido-3,5-dideoxy-α-D-glycero-D-galacto-2-nonulopyranosidonic acid (BTP3-Neu5Ac), was developed for visualization of sialidase activity. BTP3-Neu5Ac can easily and rapidly perform histochemical fluorescent visualization of influenza viruses and virus-infected cells without an antiviral antibody and cell fixation. In the present study, the potential utility of BTP3-Neu5Ac for rapid detection of mumps virus was demonstrated. BTP3-Neu5Ac could visualize dot-blotted mumps virus, virus-infected cells, and plaques (plaques should be called focuses due to staining of infected cells in this study), even if a CPE was not observed. Furthermore, virus cultivation was possible by direct pick-up from a fluorescent focus. In conventional methods, visible appearance of the CPE and focuses often requires more than 6 days after infection, but the new method with BTP3-Neu5Ac clearly visualized infected cells after 2 days and focuses after 4 days. The BTP3-Neu5Ac assay is a precise, easy, and rapid assay for confirmation and titration of mumps virus. PMID:26629699

  3. 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

  4. Ultrastructural immunohistochemical localization of virus in acute and chronic demyelinating Theiler's virus infection.

    PubMed Central

    Dal Canto, M. C.; Lipton, H. L.

    1982-01-01

    Mice experimentally infected with Theiler's murine encephalomyelitis virus (TMEV) develop a persistent infection of the central nervous system (CNS). The most striking feature of this infection is the occurrence of inflammatory primary demyelination in the spinal cord white matter. The pathogenesis of myelin degeneration in this model has not been clarified, but morphologic and immunologic data suggest that the host immune response plays a major role in the production of myelin injury. Because of low virus titers in infected adult mice and of the small size of TMEV, virus particles have never been observed in this demyelinating model. Yet elucidation of the types of cells in the CNS supporting virus replication would be important for a better understanding of both virus persistence and virus-induced demyelinating pathology. The present paper is a sequential study of the localization of TMEV in the spinal cord in infected mice by ultrastructural immunohistochemical techniques. Results indicate that virus replication is mainly in neurons during the acute phase of the disease, while in the chronic phase viral inclusions are mainly found in macrophages in and around demyelinating lesions. Other cells are also infected, but to a lesser degree. In the neuronal system both axoplasmic and dendritic flow appear to facilitate the spread of virus in the CNS. In macrophages, the presence of virus particles and the association of virus with altered components of the cytoskeleton support active virus production rather than simple internalization. The macrophage appears to play an important role in both the establishment of virus persistence and in the process of demyelination in this animal model. Images Figure 1 and 2 Figure 3 and 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10-12 Figure 13 Figure 14 Figure 15 and 16 PMID:6275708

  5. Recombinant Vesicular Stomatitis VirusBased Vaccines Against Ebola and Marburg Virus Infections

    PubMed Central

    Feldmann, Heinz

    2011-01-01

    The filoviruses, Marburg virus and Ebola virus, cause severe hemorrhagic fever with a high mortality rate in humans and nonhuman primates. Among the most-promising filovirus vaccines under development is a system based on recombinant vesicular stomatitis virus (rVSV) that expresses a single filovirus glycoprotein (GP) in place of the VSV glycoprotein (G). Importantly, a single injection of blended rVSV-based filovirus vaccines was shown to completely protect nonhuman primates against Marburg virus and 3 different species of Ebola virus. These rVSV-based vaccines have also shown utility when administered as a postexposure treatment against filovirus infections, and a rVSV-based Ebola virus vaccine was recently used to treat a potential laboratory exposure. Here, we review the history of rVSV-based vaccines and pivotal animal studies showing their utility in combating Ebola and Marburg virus infections. PMID:21987744

  6. Inhalational monkeypox virus infection in cynomolgus macaques

    PubMed Central

    Barnewall, Roy E.; Fisher, David A.; Robertson, Ashley B.; Vales, Pauline A.; Knostman, Katherine A.; Bigger, John E.

    2012-01-01

    An inhalation exposure system was characterized to deliver aerosolized monkeypox virus (MPXV), and a non-human primate (NHP) inhalation monkeypox model was developed in cynomolgus macaques. A head-only aerosol exposure system was characterized, and two sampling methods were evaluated: liquid impingement via an impinger and impaction via a gelatin filter. The aerosol concentrations obtained with the gelatin filter and impinger were virtually identical, indicating that either method is acceptable for sampling aerosols containing MPXV. The mass median aerodynamic diameter (MMAD) for individual aerosol tests in the aerosol system characterization and the NHP study ranged from 1.08 to 1.15 ?m, indicating that the aerosol particles were of a sufficient size to reach the alveoli. Six cynomolgus macaques (four male and two female) were used on study. The animals were aerosol exposed with MPXV and received doses between 2.51 104 to 9.28 105 plaque forming units (PFUs) inhaled. Four of the six animals died or were euthanized due to their moribund conditions. Both animals that received the lowest exposure doses survived to the end of the observation period. The inhalation LD50 was determined to be approximately 7.8 104 pfu inhaled. These data demonstrate that an inhalation MPXV infection model has been developed in the cynomolgus macaque with disease course and lethal dose similar to previously published data. PMID:23061051

  7. Hepatitis delta virus infection: open issues.

    PubMed

    Niro, Grazia Anna; Gioffreda, Domenica; Fontana, Rosanna

    2011-01-01

    Hepatitis delta virus (HDV) consists of a circular single-stranded RNA genome which assembles two viral proteins and acquires a lipid envelope in which the hepatitis B surface antigens (HBsAg) are embedded. HDV does not encode its own polymerase, but exploits a cellular enzyme for its replication. A better understanding of the mechanisms of HDV replication mechanism would provide new insights for antiviral strategies. Based on genomic variability, eight major genotypes of HDV have been identified, which differ as much as 40% in the nucleotide sequence. The cloning of HDV-RNA has provided genetic probes for the measurement of HDV-RNA in serum and liver; the sensitivity of HDV-RNA detection improved significantly when the reverse transcriptase-polymerase chain reaction (PCR) technique was introduced. As no commercial test is standardized for viral load detection, home-made assays have been developed in the different referral centers, which may not be comparable. Quantification of HDV in serum by real-time PCR has been recently proposed in the management of chronically infected patients. No specific inhibitors of HDV are available at present and, in spite of the crucial relationship between HDV and HBV, drugs that block HBV have only a theoretical but no sound effect on HDV replication. PMID:21195367

  8. 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

  9. SEN virus infection--a new hepatitis virus: a review.

    PubMed

    Sehgal, R

    2003-04-01

    Approximately 10% of transfusion associated hepatitis and 20% of community acquired hepatitis cases do not have a defined etiology, suggesting the existence of an additional causative agent. The recent agents which have been detected in blood were Hepatitis G virus (HGV) and TT virus (TTV), members of the family Circoviridae. These viruses were initially thought to be associated with post-transfusion hepatitis but later studies negated this causal effect. Recently, a novel DNA virus at the moment designated as SEN virus (SEN-V) was discovered and is thought to be associated with post-transfusion hepatitis. This virus is related to the above two agents and belongs to the same family. Whether, like HGV and TTV causal relationship with hepatitis is finally confirmed only time will tell, but, at the moment the association appears to present. The present review summarizes the present available data on this new agent of hepatitis. PMID:15022932

  10. Neutralizing Antibodies after Infection with Dengue 1 Virus

    PubMed Central

    Alvarez, Mayling; Rodriguez-Roche, Rosmari; Bernardo, Ldice; Montes, Tibaire; Vazquez, Susana; Morier, Luis; Alvarez, Angel; Gould, Ernest A; Halstead, Scott B

    2007-01-01

    Severity of disease is markedly increased when infection with dengue virus type 2 (DENV-2) follows infection with DENV-1. Studies have shown that heterologous neutralizing antibody titers are inversely correlated with severity of a second infection. If this mechanism controlled disease severity in Cuba, heterotypic antibody titers should have declined over time. To determine whether phenotypic changes in dengue antibodies occur over time, we analyzed serum samples collected 48 and 2022 years after DENV-1 infection. We found a significant increase in mean titer of homologous DENV-1 neutralizing antibodies and a significant decrease in heterologous antibodies to 1 of 2 genotypes of DENV-2 virus (the American genotype). Asian DENV-2 viruses were not neutralized during either interval; however, the American genotype underwent phenotypic changes in heterotypic viral neutralizing antibodies in the predicted direction. This finding may be related to the time-dependent changes in severity of disease found with secondary dengue infection. PMID:17479892

  11. 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

  12. Cell Fusion by Canine Distemper Virus-Infected Cells

    PubMed Central

    Rankin, Anne M.; Fisher, Linda E.; Bussell, Robert H.

    1972-01-01

    AV3 cells (continuous human amnion) infected with the Onderstepoort strain of canine distemper virus produced cell fusion within 2 to 5 hr when added to AV3 cell monolayers. An apparent requirement for intact, infected cells was demonstrated by showing that (i) frozen-and-thawed infected cells failed to induce fusion, (ii) infected cells frozen in the presence of glycerol retained their ability to induce fusion, (iii) infected cells subjected to swelling in hypotonic buffer and homogenization lost their ability to fuse cells, and (iv) semipurified and concentrated virus preparations with infectivity titers as high as 107.5 mean tissue culture doses per ml failed to induce fusion within 5 hr. Preparations of intact, infected cells had a mean log10 ratio of infectivity to fusion activity of 3.6. Treatment with beta-propiolactone rendered the active preparations free from detectable infectivity while they retained their ability to cause cell fusion. Cycloheximide did not block the formation of syncytia in assay cells. This type of cell fusion was neutralized by canine distemper virus immune antisera, and measles virus immune sera showed a slight degree of cross-neutralization. Other cell lines, HEp-2, MA 139 (embryonic ferret lung), MA 104 (embryonic rhesus monkey kidney), and Vero (African green monkey kidney) were also susceptible. PMID:4644630

  13. 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...

  14. 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...

  15. Contrasting effects of immunosuppression on Theiler's virus infection in mice.

    PubMed Central

    Lipton, H L; Canto, C D

    1977-01-01

    In the present study, cyclophosphamide and rabbit anti-mouse thymocyte serum were used to immunosuppress SJL/J mice infected with Theiler's mouse encephalomyelitis virus (TMEV) in order to delineate the potential mechanism(s) of virus-induced cellular injury in this infection. Whereas both immunosuppressive agents produced a significant increase in mortality, this treatment had differing effects on the pathological involvement of gray and white-matter structures in the central nervous system. The central nervous system of immunosuppressed TMEV-infected mice had increased microglial cell proliferation and neuronal necrosis, longer maintenance of high virus levels and spread of virus antigen to involve the neocortex and hippocampal complex. These observations indicate that TMEV causes a cytolotic infection of neurons and possibly other cells in gray matter. In contrast, immunosuppression produced a dramatic reduction in mononuclear inflammatory cells in the leptomeninges and spinal cord white matter of infected mice and prevented demyelination. Further, virus antigen was not detected in the leptomeninges and white matter of immunosuppressed and infected mice. These findings suggest that demyelination of TMEV infection is immune mediated. Images PMID:192679

  16. 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

  17. 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 tropism of the virus for an essential but poorly characterized organ in the digestive tract, the crop. Our results may have relevance for other members of the Dicistroviridae, some of which are pathogenic to beneficial or pest insect species. PMID:25253354

  18. 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

  19. Characteristics of Mild Dengue Virus Infection in Thai Children

    PubMed Central

    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.

    2013-01-01

    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

  20. 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

  1. Natural infection of turkeys by infectious laryngotracheitis virus.

    PubMed

    Portz, Cristiana; Beltro, Nilzane; Furian, Thales Quedi; Jnior, Alfredo Bianco; Macagnan, Marisa; Griebeler, Josiane; Lima Rosa, Carlos Andr Veiga; Colodel, Edson Moleta; Driemeier, David; Back, Alberto; Barth Schatzmayr, Ortrud Monika; Canal, Cludio 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

  2. The Role of Virus Infection in Deregulating the Cytokine Response to Secondary Bacterial Infection.

    PubMed

    Mehta, Divya; Petes, Carlene; Gee, Katrina; Basta, Sameh

    2015-12-01

    Proinflammatory cytokines are produced by macrophages and dendritic cells (DCs) after infection to stimulate T helper (Th) cells, linking innate and adaptive immunity. Virus infections can deregulate the proinflammatory cytokine response like tumor necrosis factor-? and interleukin (IL)-2, making the host more susceptible to secondary bacterial infections. Studies using various viruses such as lymphocytic choriomeningitis virus, influenza A virus, and human immunodeficiency virus have revealed several intriguing mechanisms that account for the increased susceptibility to several prevalent bacterial infections. In particular, type I interferons induced during a virus infection have been observed to play a role in suppressing the production of some key antibacterial proinflammatory cytokines such as IL-23 and IL-17. Other suppressive mechanisms as a result of cytokine deregulation by viral infections include reduced function of immune cells such as DC, macrophage, natural killer, CD4(+), and CD8(+) T cells leading to impaired clearance of secondary bacterial infections. In this study, we highlight some of the immune mechanisms that become deregulated by viral infections, and can thus become defective during secondary bacterial infections. PMID:26308503

  3. Analysis of multiple virus-infected grapevine plant reveals persistence but uneven virus distribution.

    PubMed

    Kominek, P; Glasa, M; Kominkova, M

    2009-01-01

    LN33 grapevine plants were artificially inoculated with budwoods originating from a field-cultivated Traminer grapevine which was naturally infected with Grapevine leafroll-associated virus 1 (GLRaV-1), Grapevine virus A (GVA), Grapevine virus B (GVB), Rupestris stem pitting-associated virus (RSPaV), and an unclassified tymovirus. Four years after inoculation, a comparison of the cane weights between healthy and infected grapevines did not show any significant difference. Corky bark symptoms or destructive effects of GVB infection never appeared on the infected grapevines. Dormant canes, sampled before the beginning of the vegetation period, were used for detection of grapevine viruses by ELISA or RT-PCR. ELISA turned out unexpectedly to be more effective than RT-PCR for detecting GLRaV-1 probably due to an insufficient specificity of the primers used, not reflecting the actual genetic variability of the virus. Distribution of viruses in the infected grapevines showed a different degree of irregularity in dependence on individual viruses. Therefore, in order to properly verify the sanitary status of grapevines under testing, several random samples from different parts of a tested plant have to be analyzed. PMID:19941393

  4. 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 ( ...

  5. Role of the vacuolar-ATPase in Sindbis virus infection.

    PubMed

    Hunt, Sabrina R; Hernandez, Raquel; Brown, Dennis T

    2011-02-01

    Bafilomycin A(1) is a specific inhibitor of the vacuolar-ATPase (V-ATPase), which is responsible for pH homeostasis of the cell and for the acidification of endosomes. Bafilomycin A(1) has been commonly used as a method of inhibition of infection by viruses known or suspected to follow the path of receptor-mediated endocytosis and low-pH-mediated membrane fusion. The exact method of entry for Sindbis virus, the prototype alphavirus, remains undetermined. To further investigate the role of the V-ATPase in Sindbis virus infection, the effects of bafilomycin A(1) on the infection of BHK and insect cells by Sindbis virus were studied. Bafilomycin A(1) was found to block the expression of a virus-encoded reporter gene in both infection and transfection of BHK cells. The inhibitory effects of bafilomycin A(1) were found to be reversible. The results suggest that in BHK cells in the presence of bafilomycin A(1), virus RNA enters the cell and is translated, but replication and proper folding of the product proteins requires the function of the V-ATPase. Bafilomycin A(1) had no significant effect on the outcome of infection in insect cells. PMID:21084471

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

    PubMed Central

    Salgado, Doris Martha; Eltit, Jos Miguel; Mansfield, Keith; Panqueba, Csar; Castro, Dolly; Vega, Martha Rocio; Xhaja, Kris; Schmidt, Diane; Martin, Katherine J.; Allen, Paul D.; Rodriguez, Jairo Antonio; Dinsmore, Jonathan H.; Lpez, Jos 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

  7. Outbreak of West Nile Virus Infection in Greece, 2010

    PubMed Central

    Papa, Anna; Theocharopoulos, George; Dougas, Georgios; Athanasiou, Maria; Detsis, Marios; Baka, Agoritsa; Lytras, Theodoros; Mellou, Kassiani; Bonovas, Stefanos; Panagiotopoulos, Takis

    2011-01-01

    During 2010, an outbreak of West Nile virus infection occurred in Greece. A total of 197 patients with neuroinvasive disease were reported, of whom 33 (17%) died. Advanced age and a history of heart disease were independently associated with death, emphasizing the need for prevention of this infection in persons with these risk factors. PMID:22000357

  8. ROLE OF MONOCYTES IN RESPIRATORY SYNCTIAL VIRUS (RSV) INFECTION.

    EPA Science Inventory

    ROLE OF MONOCYTES IN RESPIRATORY SYNCYTIAL VIRUS (RSV) INFECTION.
    Joleen M. Soukup and Susanne Becker, National Health and Environmental Effects Research
    Laboratory, US EPA, Research Traingle Park, NC USA.

    RSV infection in airway epithelial cells (EC) results i...

  9. Neuromuscular manifestations of west nile virus infection.

    PubMed

    Leis, A Arturo; Stokic, Dobrivoje S

    2012-01-01

    The most common neuromuscular manifestation of West Nile virus (WNV) infection is a poliomyelitis syndrome with asymmetric paralysis variably involving one (monoparesis) to four limbs (quadriparesis), with or without brainstem involvement and respiratory failure. This syndrome of acute flaccid paralysis may occur without overt fever or meningoencephalitis. Although involvement of anterior horn cells in the spinal cord and motor neurons in the brainstem are the major sites of pathology responsible for neuromuscular signs, inflammation also may involve skeletal or cardiac muscle (myositis, myocarditis), motor axons (polyradiculitis), and peripheral nerves [Guillain-Barr syndrome (GBS), brachial plexopathy]. In addition, involvement of spinal sympathetic neurons and ganglia provides an explanation for autonomic instability seen in some patients. Many patients also experience prolonged subjective generalized weakness and disabling fatigue. Despite recent evidence that WNV may persist long-term in the central nervous system or periphery in animals, the evidence in humans is controversial. WNV persistence would be of great concern in immunosuppressed patients or in those with prolonged or recurrent symptoms. Support for the contention that WNV can lead to autoimmune disease arises from reports of patients presenting with various neuromuscular diseases that presumably involve autoimmune mechanisms (GBS, other demyelinating neuropathies, myasthenia gravis, brachial plexopathies, stiff-person syndrome, and delayed or recurrent symptoms). Although there is no specific treatment or vaccine currently approved in humans, and the standard remains supportive care, drugs that can alter the cascade of immunobiochemical events leading to neuronal death may be potentially useful (high-dose corticosteroids, interferon preparations, and intravenous immune globulin containing WNV-specific antibodies). Human experience with these agents seems promising based on anecdotal reports. PMID:22461779

  10. Seronegative Hepatitis C Virus Infection in a Child Infected via Mother-to-Child Transmission

    PubMed Central

    Larouche, Ariane; Gatan, Genevive; El-Bilali, Nabil; Quesnel-Vallires, Mathieu; Martin, Steven R.; Alvarez, Fernando; Shoukry, Naglaa H.

    2012-01-01

    Hepatitis C virus (HCV) infection typically leads to antibody response within weeks after primary infection. Here, we describe the case of a child infected with HCV by mother-to-child transmission who remained persistently seronegative despite the presence of high levels of circulating HCV RNA. PMID:22535990

  11. The chimpanzee model for hepatitis B virus infection.

    PubMed

    Wieland, Stefan F

    2015-06-01

    Even before the discovery of hepatitis B virus (HBV), it was known that chimpanzees (Pan troglodytes) are susceptible to human hepatitis viruses. The chimpanzee is the only primate animal model for HBV infections. Much like HBV-infected human patients, chimpanzees can develop acute and chronic HBV infections and consequent hepatitis. Chimpanzees also develop a cellular immune response similar to that observed in humans. For these reasons, the chimpanzee has proven to be an invaluable model for investigations on HBV-driven disease pathogenesis and also the testing of novel antiviral therapies and prophylactic approaches. PMID:26033082

  12. Passive antibody protection of cats against feline immunodeficiency virus infection.

    PubMed Central

    Hohdatsu, T; Pu, R; Torres, B A; Trujillo, S; Gardner, M B; Yamamoto, J K

    1993-01-01

    All six cats passively immunized with sera from either feline immunodeficiency virus (FIV)-vaccinated cats or cats infected with FIV (Petaluma strain) were protected from homologous FIV infection at a challenge dose that infected all six control cats. Passive immunization with sera from cats vaccinated with uninfected allogeneic T cells used to grow the vaccine virus did not protect either of two cats against the same FIV challenge. These results suggest that antiviral humoral immunity, perhaps in synergy with anticellular antibodies, may be responsible for previously reported vaccine protection. PMID:8383246

  13. Virus Enrichment for Single Virus Infection by Using 3D Insulator Based Dielectrophoresis

    PubMed Central

    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 m/s) and brought it infected with a selected single H292 cell. PMID:24918921

  14. Natural history of chronic hepatitis B virus infection.

    PubMed

    Busch, Katrin; Thimme, Robert

    2015-02-01

    Hepatitis B virus infection represents a major global health problem. Currently, there are more than 240 million chronically infected people worldwide. The development of chronic hepatitis B virus-mediated liver disease may lead to liver fibrosis, cirrhosis and eventually hepatocellular carcinoma. Recently, the discovery of the viral entry receptor sodium taurocholate cotransporting polypeptide has facilitated new approaches for a better understanding of viral physiopathology. Hopefully, these novel insights may give rise to the development of more effective antiviral therapy concepts during the next years. In this review, we will discuss the natural history of hepatitis B virus infection including the viral biology, the clinical course of infection and the role of the immune response. PMID:25540037

  15. 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, an immunosuppressive virus. IBV was detected in 3 nasal swabs from PRRSV-seropositive pigs by real-time reverse transcription-PCR and sequencing. Moreover, both lineages of IBV were able to infect pigs under experimental conditions, with transmissibility of influenza B/Victoria lineage virus among pigs being observed. Our results demonstrate that pigs are susceptible to IBV infections, indicating that IBV is a swine pathogen, and swine may serve as a natural reservoir of IBVs. In addition, pigs may serve as a model to study the mechanisms of transmission and pathogenesis of IBVs. PMID:25673727

  16. Finding a cure for human immunodeficiency virus-1 infection.

    PubMed

    Blankson, Joel N; Siliciano, Janet D; Siliciano, Robert F

    2014-12-01

    Remarkable advances have been made in the treatment of human immunodeficiency virus (HIV)-1 infection, but in the entire history of the epidemic, only 1 patient has been cured. Herein we review the fundamental mechanisms that render HIV-1 infection difficult to cure and then discuss recent clinical and experimental situations in which some form of cure has been achieved. Finally, we consider approaches that are currently being taken to develop a general cure for HIV-1 infection. PMID:25277513

  17. 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.

  18. Herpes simplex virus glycoprotein D mediates interference with herpes simplex virus infection.

    PubMed Central

    Johnson, R M; Spear, P G

    1989-01-01

    We showed that the expression of a single protein, glycoprotein D (gD-1), specified by herpes simplex virus type 1 (HSV-1) renders cells resistant to infection by HSV but not to infection by other viruses. Mouse (LMtk-) and human (HEp-2) cell lines containing the gene for gD-1 under control of the human metallothionein promoter II expressed various levels of gD-1 constitutively and could be induced to express higher levels with heavy metal ions. Radiolabeled viruses bound equally well to gD-1-expressing and control cell lines. Adsorbed viruses were unable to penetrate cells expressing sufficient levels of gD-1, based on lack of any cytopathic effects of the challenge virus and on failure to detect either the induction of viral protein synthesis or the shutoff of host protein synthesis normally mediated by a virion-associated factor. The resistance to HSV infection conferred by gD-1 expression was not absolute and depended on several variables, including the amount of gD-1 expressed, the dosage of the challenge virus, the serotype of the challenge virus, and the properties of the cells themselves. The interference activity of gD-1 is discussed in relation to the role of gD-1 in virion infectivity and its possible role in permitting escape of progeny HSV from infected cells. Images PMID:2536105

  19. Secondary dengue virus type 4 infections in Vietnam.

    PubMed

    Buchy, Philippe; Vo, Van Luong; Bui, Khanh Toan; Trinh, Thi Xuan Mai; Glaziou, Philippe; Le, Thi Thu Ha; Le, Viet Lo; Bui, Trong Chien

    2005-01-01

    This study was designated to describe clinical and biological features of patients with a suspected diagnosis of dengue fever/dengue hemorrhagic fever during an outbreak in Central Vietnam. One hundred and twenty-five consecutive patients hospitalized at Khanh Hoa and Binh Thuan Provincial hospitals between November 2001 and January 2002 with a diagnosis of suspected dengue infection were included in the present study. Viruses were isolated in C6/36 and VERO E6 cell cultures or detected by RT-PCR. A hemagglutination-inhibition test (HI) was done on each paired sera using dengue antigens type 1-4, Japanese encephalitis (JE) virus antigen, Chickungunya virus antigen and Sindbis virus antigen. Anti-dengue and anti-JE virus IgM were measured by a capture enzyme-linked immunosorbent assay (MAC-ELISA). Anti-dengue and anti-JE virus IgG were measured by an ELISA test. Dengue viruses were isolated in cell culture and/or detected by RT-PCR in 20.8% of blood samples. DEN-4 and DEN-2 serotypes were found in 18.4% and 2.4% of the patients, respectively. A total of 86.4% of individuals had a diagnosis of acute dengue fever by using the HI test and/or dengue virus-specific IgM capture-ELISA and/or virus isolation and/or RT-PCR. The prevalence of primary and secondary acute dengue infection was 4% and 78.4%, respectively. Anti-dengue IgG ELISA test was positive in 88.8% of the patients. In 5 cases (4%), Japanese encephalitis virus infection was positive by serology but the cell culture was negative. No Chickungunya virus or Sindbis virus infection was detected by the HI test. In patients with acute dengue virus infection, the most common presenting symptom was headache, followed by conjunctivitis, petechial rash, muscle and joint pain, nausea and abdominal pain. Four percent of hospitalized patients were classified as dengue hemorrhagic fever. The clinical presentation and blood cell counts were similar between patients hospitalized with acute dengue fever and patients with other febrile illnesses. PMID:15906664

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

    PubMed

    Alonso-Villaverde, Carlos; Menndez, 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

  1. 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....

  2. 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 ubiquitous green microalga Ostreococcus. This study provides the first glimpse into the diversity of predicted gene functions in Ostreococcus viruses originating from distant sites and provides new insights into potential host distributions and restrictions in the world oceans. PMID:25787287

  3. Dissecting the Role of COPI Complexes in Influenza Virus Infection

    PubMed Central

    Sun, Eileen; He, Jiang

    2013-01-01

    As an obligate pathogen, influenza virus requires host cell factors and compartments to mediate productive infection and to produce infectious progeny virus. Recently, several small interfering RNA (siRNA) knockdown screens revealed influenza virus host dependency proteins, all of which identified at least two subunits of the coat protein I (COPI) complex. COPI proteins oligomerize to form coated vesicles that transport contents between the Golgi apparatus and the endoplasmic reticulum, and they have also been reported to mediate endosomal trafficking. However, it remains unclear which steps in the influenza virus infection cycle rely on the COPI complex. Upon systematic dissection of the influenza virus infection cycle, from entry to progeny virion production, we found that prolonged exposure to COPI complex disruption through siRNA depletion resulted in significant defects in virus internalization and trafficking to late endosomes. Acute inhibition of COPI complex recruitment to the Golgi apparatus with pharmacological compounds failed to recapitulate the same entry defects as observed with the COPI-depleted cells but did result in specific decreases in viral membrane protein expression and assembly, leading to defects in progeny virion production. Taken together, our findings suggest that COPI complexes likely function indirectly in influenza virus entry but play direct roles in viral membrane protein expression and assembly. PMID:23255804

  4. Clinical and molecular pathogenesis of varicella virus infection.

    PubMed

    Gilden, Donald H; Cohrs, Randall J; Mahalingam, Ravi

    2003-01-01

    Varicella zoster virus (VZV) is a neurotropic human herpesvirus that infects nearly all humans and causes chickenpox (varicella). After chickenpox, VZV becomes latent in cranial nerve, dorsal root, and autonomic nervous system ganglia along the entire neuraxis. Virus reactivation produces shingles (zoster), characterized by pain and rash usually restricted to 1-3 dermatomes. Zoster is often complicated by postherpetic neuralgia (PHN), pain that persists for months to years after rash resolves. Virus may also spread to the spinal cord and blood vessels of the brain, producing a unifocal or multifocal vasculopathy, particularly in immunocompromised individuals. The increased incidence of zoster in elderly and immunocompromised individuals appears to be due to a VZV-specific host immunodeficiency. PHN may reflect a chronic VZV ganglionitis, and VZV vasculopathy is due to productive virus infection in cerebral arteries. Strategies that might boost host cell-mediated immunity to VZV are discussed, as well as the physical state of viral nucleic acid during latency and the possible mechanisms by which herpesvirus latency is maintained and virus is reactivated. A current summary of varicella latency and pathogenesis produced by simian varicella virus (SVV), the counterpart of human VZV, points to the usefulness of a primate model of natural infection to study varicella latency, as well as the experimental model of intratracheal inoculation to study the effectiveness of antiviral agents in driving persistent varicella virus into a latent state. PMID:14583142

  5. 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.

  6. 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

  7. Epidemiology, surveillance and control of Nipah virus infections in Malaysia.

    PubMed

    Chua, K B

    2010-12-01

    The outbreak of Nipah virus, affecting pigs and pig-farm workers, was first noted in September 1998 in the north-western part of peninsular Malaysia. By March 1999, the outbreak had spread to other pig-farming areas of the country, inclusive of the neighbouring country, Singapore. A total of 283 human cases of viral encephalitis with 109 deaths were recorded in Malaysia from 29 September 1998 to December 1999. During the outbreak period, a number of surveillances under three broad groups; Surveillance in Human Health Sector, Surveillance in Animal Health Sector, and Surveillance for the Reservoir Hosts, were carried out to determine the prevalence, risk of virus infections and transmission in human and swine populations as well as the source and reservoir hosts of Nipah virus. Surveillance data showed that the virus spread rapidly among pigs within infected farms and transmission was attributed to direct contact with infective excretions and secretions. The spread of the virus among pig farms within and between states of peninsular Malaysia was due to movement of pigs. The transmission of the virus to humans was through close contact with infected pigs. Human to human transmission was considered a rare event though the Nipah virus could be isolated from saliva, urine, nasal and pharyngeal secretions of patients. Field investigations identified fruitbats of the Pteropid species as the natural reservoir hosts of the viruses. The outbreak was effectively brought under control following the discovery of the virus and institution of correct control measures through a combined effort of multi-ministerial and multidisciplinary teams working in close co-operation and collaboration with other international agencies. PMID:21329176

  8. 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

  9. Co-infection between influenza virus and flagellated bacteria.

    PubMed

    Mancini, Dalva Assunção Portari; Mendonça, Rita Maria Zucatelli; Dias, Andrea Luppi Fernandes; Mendonça, Ronaldo Zucatelli; Pinto, José Ricardo

    2005-01-01

    Trypsin is required in the hemagglutinin (HA) cleavage to in vitro influenza viruses activation. This HA cleavage is necessary for virus cell entry by receptor-mediated endocytosis. Bacteria in the respiratory tract are potential sources of proteases that could contribute to the cleavage of influenza virus in vivo. From 47 samples collected from horses, pigs, and from humans, influenza presence was confirmed in 13 and these samples demonstrated co-infection of influenza with flagellated bacteria, Stenotrophomonas maltophilia from the beginning of the experiments. Despite treatment with antibiotics, the bacteria remained resistant in several of the co-infected samples (48.39%). These bacteria, considered opportunistic invaders from environmental sources, are associated with viral infections in upper respiratory tract of hosts. The protease (elastase), secreted by Stenotrophomonas maltophilia plays a role in the potentiation of influenza virus infection. Proteolytic activity was detected by casein agar test. Positive samples from animals and humans had either a potentiated influenza infectivity or cytopathic effect (CPE) in MDCK and NCI H292 cells, Stenotrophomonas maltophilia were always present. Virus and bacteria were observed ultrastructurally. These in vitro findings show that microbial proteases could contribute to respiratory complications by host protease activity increasing inflammation or destroying endogenous cell protease inhibitors. PMID:16302111

  10. Evidence for negative-strand RNA virus infection in fungi.

    PubMed

    Kondo, Hideki; Chiba, Sotaro; Toyoda, Kazuhiro; Suzuki, Nobuhiro

    2013-01-20

    Fungal viruses comprise two groups: a major group of five families with double-stranded RNA genomes and a minor group with positive-sense single-stranded (ss)RNA genomes. Although many fungal viruses have been identified, no negative-stranded (-)ssRNA mycoviruses have been reported. Here we present two lines of evidence suggesting the presence of (-)ssRNA viruses in filamentous fungi based on an exhaustive search using extant (-)ssRNA viruses as queries. This revealed (-)ssRNA virus L protein-like sequences in the genome of a phytopathogenic obligate ascomycete, Erysiphe pisi. A similar search for (-)ssRNA viruses in fungal transcriptome shotgun assembly libraries demonstrated that two independent libraries from Sclerotinia homoeocarpa, another phytopathogenic ascomycete, contained several sequences considered to correspond to the entire mononegavirus L gene and likely originating from an infecting (-)ssRNA virus. These results provide strong evidence for both ancient and extant (-)ssRNA virus infections in fungi. PMID:23099204

  11. The susceptibility of pregnant mice to encephalomyocarditis (EMC) virus infection on different days of gestation.

    PubMed

    Nakayama, Yumi; Su, Weiping; Katayama, Kei-Ichi; Nakayama, Hiroyuki; Doi, Kunio

    2004-04-01

    Pregnant mice of the BALB/c CrSlc strain were experimentally infected with the D variant of encephalomyocarditis virus (EMC-D, 5 x 10(2) PFU/head) on three different gestational days (GD). Mice were intraperitoneally inoculated with EMC-D on 11, 13 and 15 GD and sacrificed 3 days post inoculation. There was no significant difference in the fetal mortality among all inoculation groups. Placenta showed higher virus titer than fetus and dam's serum in all inoculation groups, and the virus titer of the fetus was lowest in the 15GD group. Histopathological changes and signals of viral RNAs detected by in situ hybridization were observed almost restricted to the spongiotrophoblast layer of the placenta in all inoculation groups, and the signals were strongest in the 11GD group. In the fetus of the11GD group, signals of viral RNAs were also seen in myocardium and hepatocytes. Ultrastructurally, intracytoplasmic aggregations of virus-like particles in crystalline array were observed in trophoblast cells and giant cells in the spongiotrophoblast layer in all inoculation groups. PMID:15153681

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

    PubMed

    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

    2015-09-01

    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-?. 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

  13. 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-?. 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

  14. Novel clinical features of recurrent human respiratory syncytial virus infections

    PubMed Central

    Yui, Ikuko; Fujino, Motoko; Sawada, Akihito; Nakayama, Tetsuo

    2014-01-01

    Children and elderly individuals are often infected easily and repeatedly with human respiratory syncytial virus (HRSV); however, the features of recurrent infection in the same individual are defined poorly. To clarify the clinical significance of repeated HRSV infections in relation to subgroup epidemiology, this study performed prospective and longitudinal analyses in children with lower respiratory tract infections over 20 consecutive epidemics between 1985 and 2005 at a pediatric outpatient clinic in Kawasaki, Japan. HRSV infections were confirmed by 2 types of reverse-transcription PCR. Samples obtained from patients with repeated infections were subjected to sequence analysis and cloning analysis. A total of 1,312 lower respiratory tract infections observed in 1,010 patients were diagnosed as HRSV infections. Repeated HRSV infections occurred in 208 of the 1,010 patients. Analysis of the patients with repeated infections revealed that children were often infected multiple times even within a single short epidemic. Some patients were re-infected with strains having the same or virtually identical N gene sequences. In patients infected more than 4 times, cloning analysis revealed more frequent dual infections with both subgroups (23.8%). The HRSV-A subgroup caused subsequent homologous infections more frequently than did HRSV-B; furthermore, HRSV-A infections provided no protection from a second homologous infection. In contrast, HRSV-B infections offered significant protection against a second homologous infection. Statistical analysis revealed alleviation of symptoms with a reduced rate of dyspnoeic attacks only in the group re-infected with homologous HRSV-A strains. Thus, this study elucidates new clinical features of recurrent HRSV infection. J. Med. Virol 86: 16291638, 2014. PMID:24166209

  15. 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

  16. Establishment of a new cell line from the heart of giant grouper, Epinephelus lanceolatus (Bloch), and its application in toxicology and virus susceptibility.

    PubMed

    Guo, C Y; Huang, Y H; Wei, S N; Ouyang, Z L; Yan, Y; Huang, X H; Qin, Q W

    2015-02-01

    A new marine fish cell line, derived from the heart of giant grouper, Epinephelus lanceolatus (Bloch), was established and characterized. The cell line was designated as ELGH and subcultured with more than 60 passages. The ELGH cells were mainly composed of fibroblast-like cells and multiplied well in Leibovitz's L-15 medium supplemented with 10% foetal bovine serum (FBS) at 28 C. Chromosome analysis indicated that the modal chromosome number was 48. The fluorescent signals were detected in ELGH when transfected with green fluorescent protein reporter plasmids. The 50% cytotoxic concentration (CC50 ) of the extracellular products (ECPs) from Streptococcus iniae and Vibrio alginolyticus E333 on ELGH cells was 60.02 and 12.49 ?g mL(-1), respectively. Moreover, the ELGH cells showed susceptibility to Singapore grouper iridovirus (SGIV), but not to soft-shelled turtle iridovirus (STIV), red-spotted grouper nervous necrosis virus (RGNNV) and spring viremia of carp virus (SVCV), which was demonstrated by the presence of a severe cytopathic effect (CPE) and increased viral titres. In addition, electron microscopy observation showed that abundant virus particles were present in the infected cells. Taken together, our data above provided the potential utility of ELGH cells for transgenic and genetic manipulation, as well as cytotoxicity testing and virus pathogenesis. PMID:24372271

  17. 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

  18. 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

  19. Endocrinopathies in children infected with human immunodeficiency virus.

    PubMed

    Loomba-Albrecht, Lindsey A; Bregman, Thea; Chantry, Caroline J

    2014-09-01

    Endocrine changes (including adrenal insufficiency, disorders of growth and puberty, thyroid dysfunction, metabolic abnormalities and osteopenia) accompany human immunodeficiency virus (HIV) infection in pediatric patients. The cause of these changes is multifactorial and includes direct viral effects of HIV, and effects of antiretroviral therapy. These effects may be of particular importance in childhood given the critical developmental processes that occur during this time period and the likelihood of prolonged exposure to the virus and medications. PMID:25169569

  20. Antibody landscapes after influenza virus infection or vaccination.

    PubMed

    Fonville, J M; Wilks, S H; James, S L; Fox, A; Ventresca, M; Aban, M; Xue, L; Jones, T C; Le, N M H; Pham, Q T; Tran, N D; Wong, Y; Mosterin, A; Katzelnick, L C; Labonte, D; Le, T T; van der Net, G; Skepner, E; Russell, C A; Kaplan, T D; Rimmelzwaan, G F; Masurel, N; de Jong, J C; Palache, A; Beyer, W E P; Le, Q M; Nguyen, T H; Wertheim, H F L; Hurt, A C; Osterhaus, A D M E; Barr, I G; Fouchier, R A M; Horby, P W; Smith, D J

    2014-11-21

    We introduce the antibody landscape, a method for the quantitative analysis of antibody-mediated immunity to antigenically variable pathogens, achieved by accounting for antigenic variation among pathogen strains. We generated antibody landscapes to study immune profiles covering 43 years of influenza A/H3N2 virus evolution for 69 individuals monitored for infection over 6 years and for 225 individuals pre- and postvaccination. Upon infection and vaccination, titers increased broadly, including previously encountered viruses far beyond the extent of cross-reactivity observed after a primary infection. We explored implications for vaccination and found that the use of an antigenically advanced virus had the dual benefit of inducing antibodies against both advanced and previous antigenic clusters. These results indicate that preemptive vaccine updates may improve influenza vaccine efficacy in previously exposed individuals. PMID:25414313

  1. 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.

  2. A Review on JC Virus Infection in Kidney Transplant Recipients

    PubMed Central

    Delbue, Serena; Ferraresso, Mariano; Ghio, Luciana; Carloni, Camilla; Carluccio, Silvia; Belingheri, Mirco; Edefonti, Alberto; Ferrante, Pasquale

    2013-01-01

    The polyomavirus (PyV), JC virus (JCV), is a small nonenveloped DNA virus that asymptomatically infects about 80% of healthy adults and establishes latency in the kidney tissue. In case of immunodeficient hosts, JCV can lytically infect the oligodendrocytes, causing a fatal demyelinating disease, known as progressive multifocal leukoencephalopathy (PML). Although the reactivation of another human PyV, BK virus (BKV), is relatively common and its association with the polyomavirus associated nephropathy (PyVAN) following renal transplantation is proven, JCV replication and its impact on graft function and survival are less well studied. Here we describe the biology of JCV and its pathological features and we review the literature regarding the JCV infection analyzed in the setting of transplantations. PMID:23424601

  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 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. Human trophoblasts confer resistance to viruses implicated in perinatal infection.

    TOXLINE Toxicology Bibliographic Information

    Bayer A; Delorme-Axford E; Sleigher C; Frey TK; Trobaugh DW; Klimstra WB; Emert-Sedlak LA; Smithgall TE; Kinchington PR; Vadia S; Seveau S; Boyle JP; Coyne CB; Sadovsky Y

    2015-01-01

    OBJECTIVE: Primary human trophoblasts were previously shown to be resistant to viral infection, and able to confer this resistance to nontrophoblast cells. Can trophoblasts protect nontrophoblastic 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 48-72 hours. Diverse nonplacental human cell lines (U2OS, human foreskin fibroblast, TZM-bl, MeWo, and Caco-2) were preexposed to either trophoblast conditioned medium, nonconditioned medium, or miR-517-3p for 24 hours. Cells were infected with several viral and nonviral 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 t test or analysis of variance with Bonferroni correction.RESULTS: Infection by rubella and other togaviruses, human immunodeficiency virus-1, and varicella zoster was attenuated in cells preexposed to trophoblast-conditioned medium (P < .05), and a partial effect by the chromosome 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 attenuates viral infection in nontrophoblastic cells. Our data point to a trophoblast-specific antiviral effect that may be exploited therapeutically.

  6. In vitro infection of woodchuck hepatocytes with woodchuck hepatitis virus and ground squirrel hepatitis virus.

    PubMed

    Aldrich, C E; Coates, L; Wu, T T; Newbold, J; Tennant, B C; Summers, J; Seeger, C; Mason, W S

    1989-09-01

    Primary cultures of woodchuck hepatocytes were demonstrated to be susceptible to in vitro infection by both woodchuck hepatitis virus and ground squirrel hepatitis virus, as evidenced by the appearance of DNA species characteristic of hepadnavirus replication. Initiation of infection by woodchuck hepatitis virus was blocked by the presence of suramin, polybrene, or dideoxycytidine. Viral CCC DNA, the putative template for viral RNA transcription, was detected at 2 days postinfection. Accumulation of intracellular intermediates in virion DNA synthesis was negligible until 7-10 days postinfection, but these DNA intermediates then increased dramatically in amount over the next few weeks. Results were obtained which suggested that the prolonged accumulation of intermediates in virion DNA synthesis was an intrinsic property of the infection of individual cells, and not the result of a slow spread of virus through the cultures. PMID:2549713

  7. 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

  8. Marburg Virus Infection Detected in a Common African Bat

    PubMed Central

    Towner, Jonathan S.; Pourrut, Xavier; Albariño, César G.; Nkogue, Chimène Nze; Bird, Brian H.; Grard, Gilda; Ksiazek, Thomas G.; Gonzalez, Jean-Paul; Nichol, Stuart T.; Leroy, Eric M.

    2007-01-01

    Marburg and Ebola viruses can cause large hemorrhagic fever (HF) outbreaks with high case fatality (80–90%) in human and great apes. Identification of the natural reservoir of these viruses is one of the most important topics in this field and a fundamental key to understanding their natural history. Despite the discovery of this virus family almost 40 years ago, the search for the natural reservoir of these lethal pathogens remains an enigma despite numerous ecological studies. Here, we report the discovery of Marburg virus in a common species of fruit bat (Rousettus aegyptiacus) in Gabon as shown by finding virus-specific RNA and IgG antibody in individual bats. These Marburg virus positive bats represent the first naturally infected non-primate animals identified. Furthermore, this is the first report of Marburg virus being present in this area of Africa, thus extending the known range of the virus. These data imply that more areas are at risk for MHF outbreaks than previously realized and correspond well with a recently published report in which three species of fruit bats were demonstrated to be likely reservoirs for Ebola virus. PMID:17712412

  9. 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

  10. 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 public sewage was associated with lower infection at a nearly significant level. No other clear risk factors were identifiable. Infection was not related to travel abroad. CONCLUSIONS Our results indicate a relatively high exposure of Jeddah residents to infection by dengue viruses, which must be considered endemic to this region. Infection largely remained asymptomatic or was only associated with minor illness for which patients did not seek treatment. These results call for continued vigilance for clinical cases of dengue that may arise from this wide exposure. They also call for more extensive control efforts to reduce exposure to and transmission of dengue viruses. PMID:26917954

  11. 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

  12. Concurrent infection with influenza virus and mumps virus or pneumonia virus of mice as bearing on the inhibition of virus multiplication by bacterial polysaccharides.

    PubMed

    GINSBERG, H S; HORSFALL, F L

    1949-01-01

    Preexisting infection with PVM or mumps virus does not prevent multiplication of the virus of influenza A or B in the same tissue. Similarly, pre-existing infection with one or another of the influenza viruses does not prevent multiplication of either PVM or mumps virus in the same tissue. The failure of these two groups of viruses to interfere with the multiplication of each other is discussed in relation to the mechanism of inhibition of multiplication of mumps virus and PVM by the capsular polysaccharides of Friedlnder bacilli, and the ability of influenza A and influenza B viruses to multiply in the presence of large quantities of these carbohydrates. It is suggested that differences in the requirements of the two groups of viruses for host cell metabolic systems may serve to explain both the lack of interference between them and the differing effect of polysaccharides upon their multiplication. PMID:18099164

  13. 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, and using insect repellents when outdoors. Pregnant and lactating women can use all U.S. Environmental Protection Agency (EPA)-registered insect repellents according to the product label. PMID:26820244

  14. 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

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

    PubMed

    Susevich, Mara Laura; Marti, Gerardo Anbal; Metz, Germn Ernesto; Echeverra, Mara 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

  16. Cowpea viruses: Effect of single and mixed infections on symptomatology and virus concentration

    PubMed Central

    Taiwo, Moni A; Kareem, Kehinde T; Nsa, Imade Y; D'A Hughes, Jackies

    2007-01-01

    Natural multiple viral infections of cultivated cowpeas have been reported in Nigeria. In this study, three Nigerian commercial cowpea cultivars ("Olo 11", "Oloyin" and "White") and two lines from the IITA (IT86D- 719 and TVU 76) were mechanically inoculated with Cowpea aphid-borne mosaic virus (CABMV), Bean southern mosaic virus (SBMV) and Cowpea mottle virus (CMeV) singly, as well as in all possible combinations at 10, 20 and 30 days after planting (DAP). Samples of leaves or stems were collected at 10, 20 and 30 days after inoculation (DAI) and analyzed for relative virus concentration by Enzyme-Linked Immunosrbent Assay. All the cultivars and lines {CVS/L} were susceptible to the viruses but the commercial CVS showed more severe symptoms and had relatively higher viral concentration. In single virus infections, CABMV which induced the most severe symptoms had absorbance values (at 405 nm) of 0.11 to 0.46 while SBMV and CMeV which induced moderate symptoms had virus titre of 0.74 to 1.99 and 0.11 to 0.90 respectively. Plants inoculated 10 DAP had significantly higher virus concentration than those inoculated 30 DAP. In mixed infections involving CABMV (10 DAP) apical necrosis and death were observed in commercial cultivars "Olo 11" and "White". Enhancement of CMeV titers were observed in plants infected with CMeV + CABMV. Multiple viral infections of cowpeas may result in complete yield loss, hence, the availability of seeds of cultivars with a high level of multiple virus resistance is recommended as a means of control. PMID:17900355

  17. Plasticity and Virus Specificity of the Airway Epithelial Cell Immune Response during Respiratory Virus Infection

    PubMed Central

    Ioannidis, Ioannis; McNally, Beth; Willette, Meredith; Peeples, Mark E.; Chaussabel, Damien; Durbin, Joan E.; Ramilo, Octavio

    2012-01-01

    Airway epithelial cells (AECs) provide the first line of defense in the respiratory tract and are the main target of respiratory viruses. Here, using oligonucleotide and protein arrays, we analyze the infection of primary polarized human AEC cultures with influenza virus and respiratory syncytial virus (RSV), and we show that the immune response of AECs is quantitatively and qualitatively virus specific. Differentially expressed genes (DEGs) specifically induced by influenza virus and not by RSV included those encoding interferon B1 (IFN-B1), type III interferons (interleukin 28A [IL-28A], IL-28B, and IL-29), interleukins (IL-6, IL-1A, IL-1B, IL-23A, IL-17C, and IL-32), and chemokines (CCL2, CCL8, and CXCL5). Lack of type I interferon or STAT1 signaling decreased the expression and secretion of cytokines and chemokines by the airway epithelium. We also observed strong basolateral polarization of the secretion of cytokines and chemokines by human and murine AECs during infection. Importantly, the antiviral response of human AECs to influenza virus or to RSV correlated with the infection signature obtained from peripheral blood mononuclear cells (PBMCs) isolated from patients with acute influenza or RSV bronchiolitis, respectively. IFI27 (also known as ISG12) was identified as a biomarker of respiratory virus infection in both AECs and PBMCs. In addition, the extent of the transcriptional perturbation in PBMCs correlated with the clinical disease severity. Our results demonstrate that the human airway epithelium mounts virus-specific immune responses that are likely to determine the subsequent systemic immune responses and suggest that the absence of epithelial immune mediators after RSV infection may contribute to explaining the inadequacy of systemic immunity to the virus. PMID:22398282

  18. Hepatitis B virus infection among pregnant women in northeastern Romania.

    PubMed

    Woodruff, B A; Popovici, F; Beldescu, N; Shapiro, C N; Hersh, B S

    1993-10-01

    We conducted a serological survey of pregnant women attending prenatal clinics in northeastern Romania to determine the prevalence of hepatitis B virus (HBV) infection in this population. Overall, 162 (28%) of 573 women had evidence of past or current HBV infection, and 48 (8.4%) were carriers. The prevalence of past or current infection rose with age, but did not differ by educational level, occupation, or rural versus urban residence. Integration of hepatitis B vaccine into routine childhood immunization schedules, with the first dose given at birth, may have a substantial impact on HBV infection in Romania by preventing both perinatal and early childhood transmission. PMID:8282474

  19. Extrahepatic manifestations of chronic hepatitis C virus infection.

    PubMed

    Cacoub, Patrice; Gragnani, Laura; Comarmond, Cloe; Zignego, Anna Linda

    2014-12-15

    Hepatitis C virus (HCV) infected patients are known to be at risk of developing liver complications i.e. cirrhosis and liver cancer. However, the risks of morbidity and mortality are underestimated because they do not take into account non-liver consequences of chronic hepatitis C virus infection. Numerous extrahepatic manifestations have been reported in up to 74% of patients, from perceived to disabling conditions. The majority of data concern hepatitis C virus-related autoimmune and/or lymphoproliferative disorders, from mixed cryoglobulinaemia vasculitis to frank lymphomas. More recently, other hepatitis C virus-associated disorders have been reported including cardiovascular, renal, metabolic, and central nervous system diseases. This review aims to outline most of the extrahepatic manifestations that are currently being investigated, including some of autoimmune and/or lymphoproliferative nature, and others in which the role of immune mechanisms appears less clear. Beyond the liver, hepatitis C virus chronic infection should be analyzed as a multifaceted systemic disease leading to heavy direct and indirect costs. The accurate consideration of extrahepatic consequences of such a systemic infection significantly increases the weight of its pathological burden. The need for effective viral eradication measures is underlined. PMID:25458776

  20. Torque teno virus infection in hemodialysis patients in North India.

    PubMed

    Irshad, Mohammad; Mandal, Kishore; Singh, Shiwani; Agarwal, S K

    2010-12-01

    This study describes the prevalence and association of Torque teno virus (TTV) infection with blood-transmitted viral hepatitis including hepatitis B virus (HBV) and hepatitis C virus (HCV) infections in patients with chronic renal failure (CRF) on maintenance hemodialysis (HD). TTV infection was diagnosed by detection of TTV-DNA in serum, using the polymerase chain reaction (PCR) technique. TTV-DNA was estimated in a total number of one hundred patients with CRF and in 100 voluntary blood donors as controls. The markers of HBV and HCV were also tested in sera samples of these patients. TTV-DNA was detected in 39 of 100 patients (39%) with CRF and in 27 of 100 (27%) healthy controls. The analysis of the results demonstrated HBsAg, IgM anti-HBc, anti-HCV, and HCV core antigen in 5.0, 3.0, 6.0, and 4.0% of patients, respectively. This study could not show any association of TTV with HBV and HCV infections for the transmission pattern or any impact on severity of diseases caused by these viruses in CRF patients. TTV also could not show any association with demographic characteristics of patients, duration of dialysis, number of blood transfusions and renal/liver function of the patients. As such, this study concludes that TTV appears as a benign pathogen, showing no sign of renal/liver damage or any change in the severity of diseases caused by blood-borne hepatitis viruses. PMID:19777363

  1. 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

  2. Emerging concepts in immunity to hepatitis C virus infection

    PubMed Central

    Rosen, Hugo R.

    2013-01-01

    Since the discovery of hepatitis C virus (HCV) by molecular cloning almost a quarter of a century ago, unprecedented at the time because the virus had never been grown in cell culture or detected serologically, there have been impressive strides in many facets of our understanding of the natural history of the disease, the viral life cycle, the pathogenesis, and antiviral therapy. It is apparent that the virus has developed multiple strategies to evade immune surveillance and eradication. This Review covers what we currently understand of the temporal and spatial immunological changes within the human innate and adaptive host immune responses that ultimately determine the outcomes of HCV infection. PMID:24084744

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

    PubMed Central

    Gammon, Don B; Duraffour, Sophie; Rozelle, Daniel K; Hehnly, Heidi; Sharma, Rita; Sparks, Michael E; West, Cara C; Chen, Ying; Moresco, James J; Andrei, Graciela; Connor, John H; Conte, Darryl; Gundersen-Rindal, Dawn E; Marshall, William L; Yates, John R; Silverman, Neal; Mello, Craig C

    2014-01-01

    Virus-host interactions drive a remarkable diversity of immune responses and countermeasures. We found that two RNA viruses with broad host ranges, vesicular stomatitis virus (VSV) and Sindbis virus (SINV), are completely restricted in their replication after entry into Lepidopteran cells. This restriction is overcome when cells are co-infected with vaccinia virus (VACV), a vertebrate DNA virus. Using RNAi screening, we show that Lepidopteran RNAi, Nuclear Factor-?B, and ubiquitin-proteasome pathways restrict RNA virus infection. Surprisingly, a highly conserved, uncharacterized VACV protein, A51R, can partially overcome this virus restriction. We show that A51R is also critical for VACV replication in vertebrate cells and for pathogenesis in mice. Interestingly, A51R colocalizes with, and stabilizes, host microtubules and also associates with ubiquitin. We show that A51R promotes viral protein stability, possibly by preventing ubiquitin-dependent targeting of viral proteins for destruction. Importantly, our studies reveal exciting new opportunities to study virus-host interactions in experimentally-tractable Lepidopteran systems. DOI: http://dx.doi.org/10.7554/eLife.02910.001 PMID:24966209

  4. Insights into Head-Tailed Viruses Infecting Extremely Halophilic Archaea

    PubMed Central

    Pietilä, Maija K.; Laurinmäki, Pasi; Russell, Daniel A.; Ko, Ching-Chung; Jacobs-Sera, Deborah; Butcher, Sarah J.

    2013-01-01

    Extremophilic archaea, both hyperthermophiles and halophiles, dominate in habitats where rather harsh conditions are encountered. Like all other organisms, archaeal cells are susceptible to viral infections, and to date, about 100 archaeal viruses have been described. Among them, there are extraordinary virion morphologies as well as the common head-tailed viruses. Although approximately half of the isolated archaeal viruses belong to the latter group, no three-dimensional virion structures of these head-tailed viruses are available. Thus, rigorous comparisons with bacteriophages are not yet warranted. In the present study, we determined the genome sequences of two of such viruses of halophiles and solved their capsid structures by cryo-electron microscopy and three-dimensional image reconstruction. We show that these viruses are inactivated, yet remain intact, at low salinity and that their infectivity is regained when high salinity is restored. This enabled us to determine their three-dimensional capsid structures at low salinity to a ∼10-Å resolution. The genetic and structural data showed that both viruses belong to the same T-number class, but one of them has enlarged its capsid to accommodate a larger genome than typically associated with a T=7 capsid by inserting an additional protein into the capsid lattice. PMID:23283946

  5. Insights into head-tailed viruses infecting extremely halophilic archaea.

    PubMed

    Pietil, Maija K; Laurinmki, Pasi; Russell, Daniel A; Ko, Ching-Chung; Jacobs-Sera, Deborah; Butcher, Sarah J; Bamford, Dennis H; Hendrix, Roger W

    2013-03-01

    Extremophilic archaea, both hyperthermophiles and halophiles, dominate in habitats where rather harsh conditions are encountered. Like all other organisms, archaeal cells are susceptible to viral infections, and to date, about 100 archaeal viruses have been described. Among them, there are extraordinary virion morphologies as well as the common head-tailed viruses. Although approximately half of the isolated archaeal viruses belong to the latter group, no three-dimensional virion structures of these head-tailed viruses are available. Thus, rigorous comparisons with bacteriophages are not yet warranted. In the present study, we determined the genome sequences of two of such viruses of halophiles and solved their capsid structures by cryo-electron microscopy and three-dimensional image reconstruction. We show that these viruses are inactivated, yet remain intact, at low salinity and that their infectivity is regained when high salinity is restored. This enabled us to determine their three-dimensional capsid structures at low salinity to a ?10- resolution. The genetic and structural data showed that both viruses belong to the same T-number class, but one of them has enlarged its capsid to accommodate a larger genome than typically associated with a T=7 capsid by inserting an additional protein into the capsid lattice. PMID:23283946

  6. Mucocutaneous manifestations in children with human immunodeficiency virus infection.

    PubMed

    Mendiratta, Vibhu; Mittal, Saurabh; Jain, Arpita; Chander, Ram

    2010-01-01

    Skin is one of the most frequently involved organs in human immunodeficiency virus (HIV) infection, and mucocutaneous manifestations may be one of the earliest markers of AIDS. The prevalence of cutaneous abnormalities in HIV approaches nearly 90%. Mucocutaneous manifestations may also act as a prognostic marker of HIV infection. Children are increasingly being affected by HIV infection and it is important to realize the presence of the infection early in the disease process as their immune status is not mature enough to handle the stress of various infections. Skin manifestations can serve as early markers and prognostic indicators of HIV infection. This review highlights the epidemiology, transmission, pathogenesis, and the mucocutaneous manifestations of HIV infection in children. PMID:20826983

  7. Visualizing hepatitis C virus infection in humanized mice

    PubMed Central

    von Schaewen, Markus; Ding, Qiang; Ploss, Alexander

    2014-01-01

    Hepatitis C virus (HCV) establishes frequently persistent infections. Chronic carriers can develop severe liver disease. HCV has been intensely studied in a variety of cell culture systems. However, commonly used cell lines and primary hepatocyte cultures do not or only in part recapitulate the intricate host environment HCV faces in the liver. HCV infects readily only humans and chimpanzees, which poses challenges in studying HCV infection in vivo. Consequently, tractable small animal models are needed that are not only suitable for analyzing HCV infection but also for testing novel therapeutics. Here, we will focus our discussion on humanized mice, i.e. mice engrafted with human tissues or expressing human genes, which support HCV infection. We will further highlight novel methods that can be used to unambiguously detect HCV infected cells in situ, thereby facilitating a spatio-temporal dissection of HCV infection in the three dimensional context of the liver. PMID:24642425

  8. A case of Mayaro virus infection imported from French Guiana.

    PubMed

    Llagonne-Barets, Marion; Icard, Vinca; Leparc-Goffart, Isabelle; Prat, Christine; Perpoint, Thomas; André, Patrice; Ramière, Christophe

    2016-04-01

    Emergence of arboviruses is a rising problem in several areas in the world. Here we report a case of Mayaro virus infection that was diagnosed in a French citizen presenting a dengue-like syndrome with prolonged arthralgia following a travel in French Guiana. Diagnosis was based on serological testing, a newly developed specific RT-PCR and sequencing. The real incidence of this viral infection among travelers is poorly known but this case is the first reported in a European area where Aedes albopictus mosquitoes are established, which underscores the necessity to determine the vector competence of the European strain of this mosquito species for Mayaro virus. PMID:26921736

  9. In vivo infection by a neuroinvasive neurovirulent dengue virus.

    PubMed

    Velandia-Romero, Myriam Lucia; Acosta-Losada, Orlando; Castellanos, Jaime E

    2012-10-01

    Although neurological manifestations associated with dengue infections have been reported in endemic countries, the viral or host characteristics determining the infection or alteration of nervous function have not been described. In order to investigate neurobiological conditions related to central nervous system dengue virus (DENV) infection, we established a mouse model of neuroinfection. A DENV-4 isolate was first adapted to neuroblastoma cells, later inoculated in suckling mice brain, and finally, this D4MB-6 viral variant was inoculated intraperitoneally in Balb/c mice at different postnatal days (pnd). Virus-induced fatal encephalitis in 2 and 7 pnd mice but infected at 14 and 21 pnd mice survived. The younger mice presented encephalitis at the sixth day postinfection with limb paralysis and postural instability concomitant with efficient viral replication in brain. In this mice model, we found activated microglial cells positive to viral antigen. Neurons, oligodendrocytes, and endothelial cells were also infected by the D4MB-6 virus in neonatal mice, which showed generalized and local plasma leakage with blood-brain barrier (BBB) severe damage. These results suggest that there was a viral fitness change which led to neuroinfection only in immune or neurological immature mice. Infection of neurons, endothelial, and microglial cells may be related to detrimental function or architecture found in susceptible mice. This experimental neuroinfection model could help to have a better understanding of neurological manifestations occurring during severe cases of dengue infection. PMID:22825914

  10. 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. J. Med. Virol. 88:631-638, 2016. © 2015 Wiley Periodicals, Inc. PMID:26381440

  11. The heat shock response restricts virus infection in Drosophila

    PubMed Central

    Merkling, Sarah H.; Overheul, Gijs J.; van Mierlo, Joël T.; Arends, Daan; Gilissen, Christian; van Rij, Ronald P.

    2015-01-01

    Innate immunity is the first line of defence against pathogens and is essential for survival of the infected host. The fruit fly Drosophila melanogaster is an emerging model to study viral pathogenesis, yet antiviral defence responses remain poorly understood. Here, we describe the heat shock response, a cellular mechanism that prevents proteotoxicity, as a component of the antiviral immune response in Drosophila. Transcriptome analyses of Drosophila S2 cells and adult flies revealed strong induction of the heat shock response upon RNA virus infection. Dynamic induction patterns of heat shock pathway components were characterized in vitro and in vivo following infection with different classes of viruses. The heat shock transcription factor (Hsf), as well as active viral replication, were necessary for the induction of the response. Hsf-deficient adult flies were hypersensitive to virus infection, indicating a role of the heat shock response in antiviral defence. In accordance, transgenic activation of the heat shock response prolonged survival time after infection and enabled long-term control of virus replication to undetectable levels. Together, our results establish the heat shock response as an important constituent of innate antiviral immunity in Drosophila. PMID:26234525

  12. Cd4+ T Cell Subsets during Virus Infection

    PubMed Central

    Maloy, Kevin J.; Burkhart, Christoph; Junt, Tobias M.; Odermatt, Bernhard; Oxenius, Annette; Piali, Luca; Zinkernagel, Rolf M.; Hengartner, Hans

    2000-01-01

    To analyze the antiviral protective capacities of CD4+ T helper (Th) cell subsets, we used transgenic T cells expressing an I-Abrestricted T cell receptor specific for an epitope of vesicular stomatitis virus glycoprotein (VSV-G). After polarization into Th1 or Th2 effectors and adoptive transfer into T celldeficient recipients, protective capacities were assessed after infection with different types of viruses expressing the VSV-G. Both Th1 and Th2 CD4+ T cells could transfer protection against systemic VSV infection, by stimulating the production of neutralizing immunoglobulin G antibodies. However, only Th1 CD4+ T cells were able to mediate protection against infection with recombinant vaccinia virus expressing the VSV-G (Vacc-IND-G). Similarly, only Th1 CD4+ T cells were able to rapidly eradicate Vacc-IND-G from peripheral organs, to mediate delayed-type hypersensitivity responses against VSV-G and to protect against lethal intranasal infection with VSV. Protective capacity correlated with the ability of Th1 CD4+ T cells to rapidly migrate to peripheral inflammatory sites in vivo and to respond to inflammatory chemokines that were induced after virus infection of peripheral tissues. Therefore, the antiviral protective capacity of a given CD4+ T cell is governed by the effector cytokines it produces and by its migratory capability. PMID:10859340

  13. Historical perspective of foamy virus epidemiology and infection.

    PubMed

    Meiering, C D; Linial, M L

    2001-01-01

    Foamy viruses (FV) are complex retroviruses which are widespread in many species. Despite being discovered over 40 years ago, FV are among the least well characterized retroviruses. The replication of these viruses is different in many interesting respects from that of all other retroviruses. Infection of natural hosts by FV leads to a lifelong persistent infection, without any evidence of pathology. A large number of studies have looked at the prevalence of primate foamy viruses in the human population. Many of these studies have suggested that FV infections are prevalent in some human populations and are associated with specific diseases. More recent data, using more rigorous criteria for the presence of viruses, have not confirmed these studies. Thus, while FV are ubiquitous in all nonhuman primates, they are only acquired as rare zoonotic infections in humans. In this communication, we briefly discuss the current status of FV research and review the history of FV epidemiology, as well as the lack of pathogenicity in natural, experimental, and zoonotic infections. PMID:11148008

  14. Review: Occult hepatitis C virus infection: still remains a controversy.

    PubMed

    Vidimliski, Pavlina Dzekova; Nikolov, Igor; Geshkovska, Nadica Matevska; Dimovski, Aleksandar; Rostaing, Lionel; Sikole, Aleksandar

    2014-09-01

    Occult hepatitis C virus (HCV) infection is characterized by the presence of HCV RNA in the liver cells or peripheral blood mononuclear cells of the patients whose serum samples test negative for HCV RNA, with or without presence of HCV antibodies. The present study reviews the existing literature on the persistence of occult hepatitis C virus infection, with description of the clinical characteristics and methods for identification of occult hepatitis C. Occult hepatitis C virus infection was detected in patients with abnormal results of liver function tests of unknown origin, with HCV antibodies and HCV RNA negativity in serum, and also in patients with spontaneous or treatment-induced recovery from hepatitis C. The viral replication in the liver cells and/or peripheral blood mononuclear cells was present in all clinical presentations of occult hepatitis C. The peripheral blood mononuclear cells represent an extra-hepatic site of HCV replication. The reason why HCV RNA was not detectable in the serum of patients with occult hepatitis C, could be the low number of circulating viral particles not detectable by the diagnostic tests with low sensitivity. It is uncertain whether occult hepatitis C is a different clinical entity or just a form of chronic hepatitis C virus infection. Data accumulated over the last decade demonstrated that an effective approach to the diagnosis of HCV infection would be the implementation of more sensitive HCV RNA diagnostic assays, and also, examination of the presence of viral particles in the cells of the immune system. PMID:24895180

  15. Regulatory T Cells Resist Virus Infection-Induced Apoptosis

    PubMed Central

    Che, Jenny W.; Kraft, Anke R. M.; Selin, Liisa K.

    2014-01-01

    ABSTRACT Regulatory T (Treg) cells are important in the maintenance of self-tolerance, and the depletion of Treg cells correlates with autoimmune development. It has been shown that type I interferon (IFN) responses induced early in the infection of mice can drive memory (CD44hi) CD8 and CD4 T cells into apoptosis, and we questioned here whether the apoptosis of CD44-expressing Treg cells might be involved in the infection-associated autoimmune development. Instead, we found that Treg cells were much more resistant to apoptosis than CD44hi CD8 and CD4 T cells at days 2 to 3 after lymphocytic choriomeningitis virus infection, when type I IFN levels are high. The infection caused a downregulation of the interleukin-7 (IL-7) receptor, needed for survival of conventional T cells, while increasing on Treg cells the expression of the high-affinity IL-2 receptor, needed for STAT5-dependent survival of Treg cells. The stably maintained Treg cells early during infection may explain the relatively low incidence of autoimmune manifestations among infected patients. IMPORTANCE Autoimmune diseases are controlled in part by regulatory T cells (Treg) and are thought to sometimes be initiated by viral infections. We tested the hypothesis that Treg may die off at early stages of infection, when virus-induced factors kill other lymphocyte types. Instead, we found that Treg resisted this cell death, perhaps reducing the tendency of viral infections to cause immune dysfunction and induce autoimmunity. PMID:25473049

  16. 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

  17. Screening for Hepatitis B Virus Infection in Nonpregnant Adolescents and Adults

    MedlinePLUS

    ... Screening for Hepatitis B Virus Infection in Nonpregnant Adolescents and Adults The U.S. Preventive Services Task Force ( ... Screening for Hepatitis B Virus Infection in Nonpregnant Adolescents and Adults. This final recommendation statement applies only ...

  18. Ammonium chloride and chloroquine inhibit rabies virus infection in neuroblastoma cells. Brief report.

    PubMed

    Tsiang, H; Superti, F

    1984-01-01

    Two lysosomotropic agents, ammonium chloride and chloroquine inhibit the infection of murine neuroblastoma cells by rabies virus. The experiments indicate that rabies virus infects the neuronal cells through an endosome pH dependent entry pathway. PMID:6148053

  19. 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

  20. 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

  1. Occupational hepatitis B virus infection in sewage workers.

    PubMed

    Arvanitidou, M; Constantinidis, T C; Doutsos, J; Mandraveli, K; Katsouyannopoulos, V

    1998-01-01

    In a cross-sectional study the employees of a Sewage Company were tested for hepatitis B virus (HBV) markers--HBsAg, anti-HBs, anti-HBc--to determine the prevalence of HBV infection and assess the risk of exposed sewage workers becoming infected, so as to evaluate the necessity for appropriate vaccination. The overall prevalence of HBV markers was 43.9% and 6.6% of the employees were HBsAg carriers. In the univariate analysis the prevalence of past and current infection was significantly associated with exposure to sewage (p < 0.001), age (p < 0.001) and with educational level (p < 0.001). However, the logistic regression analysis confirmed that only exposure to sewage was independently associated with positivity for HBV infection (p < 0.001). Workers exposed to sewage should therefore be considered for vaccination against hepatitis B virus. PMID:10064948

  2. 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

  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. EpsteinBarr virus infectionRelated hemophagocytic lymphohistiocytosis

    PubMed Central

    Kumar, Navin; Mehta, Chitra; Sarma, Smita; Singh, Sumit; Mehta, Yatin

    2015-01-01

    We report a case of 27-year-old female diagnosed with hemophagocytic lymphohistiocytosis (HLH) following a recent EpsteinBarr virus (EBV) infection. A known case of relapsing remitting multiple sclerosis on corticosteroids for last 6 months presented to the critical care unit with fever, maculopapular rash and difficulty in breathing. A rapid and correct diagnosis with the precise treatment led to complete recovery of this patient. The HLH is a rare complication of primary EBV infection. PMID:26180435

  5. Vaccinia virus infection & temporal analysis of virus gene expression: part 1.

    PubMed

    Yen, Judy; Golan, Ron; Rubins, Kathleen

    2009-01-01

    The family Poxviridae consists of large double-stranded DNA containing viruses that replicate exclusively in the cytoplasm of infected cells. Members of the orthopox genus include variola, the causative agent of human small pox, monkeypox, and vaccinia (VAC), the prototypic member of the virus family. Within the relatively large (approximately 200 kb) vaccinia genome, three classes of genes are encoded: early, intermediate, and late. While all three classes are transcribed by virally-encoded RNA polymerases, each class serves a different function in the life cycle of the virus. Poxviruses utilize multiple strategies for modulation of the host cellular environment during infection. In order to understand regulation of both host and virus gene expression, we have utilized genome-wide approaches to analyze transcript abundance from both virus and host cells. Here, we demonstrate time course infections of HeLa cells with Vaccinia virus and sampling RNA at several time points post-infection. Both host and viral total RNA is isolated and amplified for hybridization to microarrays for analysis of gene expression. PMID:19488021

  6. Vaccinia virus infection & temporal analysis of virus gene expression: Part 3.

    PubMed

    Yen, Judy; Golan, Ron; Rubins, Kathleen

    2009-01-01

    The family Poxviridae consists of large double-stranded DNA containing viruses that replicate exclusively in the cytoplasm of infected cells. Members of the orthopox genus include variola, the causative agent of human small pox, monkeypox, and vaccinia (VAC), the prototypic member of the virus family. Within the relatively large (approximately 200 kb) vaccinia genome, three classes of genes are encoded: early, intermediate, and late. While all three classes are transcribed by virally-encoded RNA polymerases, each class serves a different function in the life cycle of the virus. Poxviruses utilize multiple strategies for modulation of the host cellular environment during infection. In order to understand regulation of both host and virus gene expression, we have utilized genome-wide approaches to analyze transcript abundance from both virus and host cells. Here, we demonstrate time course infections of HeLa cells with Vaccinia virus and sampling RNA at several time points post-infection. Both host and viral total RNA is isolated and amplified for hybridization to microarrays for analysis of gene expression. PMID:19365326

  7. Vaccinia virus infection & temporal analysis of virus gene expression: Part 2.

    PubMed

    Yen, Judy; Golan, Ron; Rubins, Kathleen

    2009-01-01

    The family Poxviridae consists of large double-stranded DNA containing viruses that replicate exclusively in the cytoplasm of infected cells. Members of the orthopox genus include variola, the causative agent of human small pox, monkeypox, and vaccinia (VAC), the prototypic member of the virus family. Within the relatively large (approximately 200 kb) vaccinia genome, three classes of genes are encoded: early, intermediate, and late. While all three classes are transcribed by virally-encoded RNA polymerases, each class serves a different function in the life cycle of the virus. Poxviruses utilize multiple strategies for modulation of the host cellular environment during infection. In order to understand regulation of both host and virus gene expression, we have utilized genome-wide approaches to analyze transcript abundance from both virus and host cells. Here, we demonstrate time course infections of HeLa cells with Vaccinia virus and sampling RNA at several time points post-infection. Both host and viral total RNA is isolated and amplified for hybridization to microarrays for analysis of gene expression. PMID:19363464

  8. Bird movement predicts Buggy Creek virus infection in insect vectors.

    PubMed

    Brown, Charles R; Brown, Mary Bomberger; Moore, Amy T; Komar, Nicholas

    2007-01-01

    Predicting the spatial foci of zoonotic diseases is a major challenge for epidemiologists and disease ecologists. Migratory birds are often thought to be responsible for introducing some aviozoonotic pathogens such as West Nile and avian influenza viruses to a local area, but most information on how bird movement correlates with virus prevalence is anecdotal or indirect. We report that the prevalence of Buggy Creek virus (BCRV) infection in cimicid swallow bugs (Oeciacus vicarius), the principal invertebrate vector for this virus, was directly associated with the likelihood of movement by cliff swallows (Petrochelidon pyrrhonota), an amplifying host for the virus, between nesting colonies. The prevalence of BCRV in bugs was also directly correlated with the number of swallows immigrating into a site. Birds that move into a site are often transient individuals that may have more often encountered virus elsewhere. These results indicate that the magnitude and direction of daily bird movement in a local area can accurately predict transmission foci for this virus and provide rare quantitative evidence that birds can play a critical role in the dispersal of certain vector-borne viruses. PMID:17760513

  9. 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...

  10. The Role of IKK? 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-?B cascade in the in vivo pathology. Initial studies indicated that at early time points of VEEV infection, the NF-?B 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 IKK? component of the IKK complex. Our previous studies with Rift valley fever virus, which exhibited early activation of the NF-?B cascade in infected cells, had indicated that the IKK? 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 IKK? in VEEV infected cells that resulted in formation of lower molecular weight complexes. Well-documented inhibitors of IKK? function, BAY-11-7082, BAY-11-7085 and IKK2 compound IV, were employed to determine whether IKK? 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 IKK? for VEEV replication, we over-expressed IKK? in cells and observed an increase in viral titers. In contrast, studies carried out using IKK??/? 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 IKK? may interact with the viral protein nsP3. In conclusion, our studies have revealed that the host IKK? protein may be critically involved in VEEV replication. PMID:24586253

  11. Cytokine-Mediated Immunopathogenesis of Hepatitis B Virus Infections.

    PubMed

    Li, Xuefen; Liu, Xia; Tian, Li; Chen, Yu

    2016-02-01

    Hepatitis B virus (HBV) infection is a worldwide health problem, with approximately one third of populations have been infected, among which 3-5 % of adults and more than 90 % of children developed to chronic HBV infection. Host immune factors play essential roles in the outcome of HBV infection. Thus, ineffective immune response against HBV may result in persistent virus replications and liver necroinflammations, then lead to chronic HBV infection, liver cirrhosis, and even hepatocellular carcinoma. Cytokine balance was shown to be an important immune characteristic in the development and progression of hepatitis B, as well as in an effective antiviral immunity. Large numbers of cytokines are not only involved in the initiation and regulation of immune responses but also contributing directly or indirectly to the inhibition of virus replication. Besides, cytokines initiate downstream signaling pathway activities by binding to specific receptors expressed on the target cells and play important roles in the responses against viral infections and, therefore, might affect susceptibility to HBV and/or the natural course of the infection. Since cytokines are the primary causes of inflammation and mediates liver injury after HBV infection, we have discussed recent advances on the roles of various cytokines [including T helper type 1 cells (Th1), Th2, Th17, regulatory T cells (Treg)-related cytokines] in different phases of HBV infection and cytokine-related mechanisms for impaired viral control and liver damage during HBV infection. We then focus on experimental therapeutic applications of cytokines to gain a better understanding of this newly emerging aspect of disease pathogenesis. PMID:25480494

  12. Hepatitis B and human immunodeficiency virus co-infection

    PubMed Central

    Phung, Bao-Chau; Sogni, Philippe; Launay, Odile

    2014-01-01

    Hepatitis B and human immunodeficiency virus (HBV and HIV) infection share transmission patterns and risk factors, which explains high prevalence of chronic HBV infection in HIV infected patients. The natural course of HBV disease is altered by the HIV infection with less chance to clear acute HBV infection, faster progression to cirrhosis and higher risk of liver-related death in HIV-HBV co-infected patients than in HBV mono-infected ones. HIV infected patients with chronic hepatitis B should be counseled for liver damage and surveillance of chronic hepatitis B should be performed to screen early hepatocellular carcinoma. Noninvasive tools are now available to evaluate liver fibrosis. Isolated hepatitis B core antibodies (anti-HBc) are a good predictive marker of occult HBV infection. Still the prevalence and significance of occult HBV infection is controversial, but its screening may be important in the management of antiretroviral therapy. Vaccination against HBV infection is recommended in non-immune HIV patients. The optimal treatment for almost all HIV-HBV co-infected patients should contain tenofovir plus lamivudine or emtricitabine and treatment should not be stopped to avoid HBV reactivation. Long term tenofovir therapy may lead to significant decline in hepatitis B surface Antigen. The emergence of resistant HBV strains may compromise the HBV therapy and vaccine therapy. PMID:25516647

  13. Mayaro virus infection cycle relies on casein kinase 2 activity.

    PubMed

    Barroso, Madalena M S; Lima, Carla S; Silva-Neto, Mrio A C; Da Poian, Andrea T

    2002-09-01

    Replication of Mayaro virus in Vero cells induces dramatic cytopathic effects and cell death. In this study, we have evaluated the role of casein kinase 2 (CK2) during Mayaro virus infection cycle. We found that CK2 was activated during the initial stages of infection ( approximately 36% after 4h). This activation was further confirmed when the enzyme was partially purified from the cellular lysate either by Mono Q 5/5Hr column or heparin-agarose column. Using this later column, we found that the elution profile of CK2 activity from infected cells was different from that obtained for control cell enzyme, suggesting a structural modification of CK2 after infection. Treatment of infected cells with a cell-permeable inhibitor of CK2, dichloro-1-(beta-D-ribofuranosyl)benzimidazole (DRB), abolished the cytopathic effect in a dose-dependent manner. Together this set of data demonstrates for the first time that CK2 activity in host cells is required in Mayaro virus infection cycle. PMID:12207921

  14. 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

  15. CHARACTERIZATION OF THREE NOVEL VIRUSES INFECTING RASPBERRY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During routine graft indexing at the USDA-ARS Horticultural Crops Research Laboratory in Corvallis, Oregon, USA, a Glen Clova plant that originated in Europe induced severe symptoms on indicator plants causing mottling, epinasty and apical necrosis. Testing for all Rubus viruses with available lab...

  16. Vaccinia Virus Infection in Monkeys, Brazilian Amazon

    PubMed Central

    Abraho, Jnatas S.; Silva-Fernandes, Andr T.; Lima, Larissa S.; Campos, Rafael K.; Guedes, Maria I.M.C.; Cota, Marcela M.G.; Assis, Felipe L.; Borges, Iara A.; Souza-Jnior, Milton F.; Lobato, Zlia I.P.; Bonjardim, Cludio A.; Ferreira, Paulo C.P.; Trindade, Giliane S.

    2010-01-01

    To detect orthopoxvirus in the Brazilian Amazon, we conducted a serosurvey of 344 wild animals. Neutralizing antibodies against orthopoxvirus were detected by plaque-reduction neutralizing tests in 84 serum samples. Amplicons from 6 monkey samples were sequenced. These amplicons identified vaccinia virus genetically similar to strains from bovine vaccinia outbreaks in Brazil. PMID:20507750

  17. 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.

  18. 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

  19. Global Reprogramming of Host SUMOylation during Influenza Virus Infection.

    PubMed

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

    2015-11-17

    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

  20. Lethal Nipah virus infection induces rapid overexpression of CXCL10.

    PubMed

    Mathieu, Cyrille; Guillaume, Vanessa; Sabine, Amlie; Ong, Kien Chai; Wong, Kum Thong; Legras-Lachuer, Catherine; Horvat, Branka

    2012-01-01

    Nipah virus (NiV) is a recently emerged zoonotic Paramyxovirus that causes regular outbreaks in East Asia with mortality rate exceeding 75%. Major cellular targets of NiV infection are endothelial cells and neurons. To better understand virus-host interaction, we analyzed the transcriptome profile of NiV infection in primary human umbilical vein endothelial cells. We further assessed some of the obtained results by in vitro and in vivo methods in a hamster model and in brain samples from NiV-infected patients. We found that NiV infection strongly induces genes involved in interferon response in endothelial cells. Among the top ten upregulated genes, we identified the chemokine CXCL10 (interferon-induced protein 10, IP-10), an important chemoattractant involved in the generation of inflammatory immune response and neurotoxicity. In NiV-infected hamsters, which develop pathology similar to what is seen in humans, expression of CXCL10 mRNA was induced in different organs with kinetics that followed NiV replication. Finally, we showed intense staining for CXCL10 in the brain of patients who succumbed to lethal NiV infection during the outbreak in Malaysia, confirming induction of this chemokine in fatal human infections. This study sheds new light on NiV pathogenesis, indicating the role of CXCL10 during the course of infection and suggests that this chemokine may serve as a potential new marker for lethal NiV encephalitis. PMID:22393386

  1. Epidemiology and natural history of hepatitis C virus infection

    PubMed Central

    Lee, Mei-Hsuan; Yang, Hwai-I; Yuan, Yong; LItalien, Gilbert; Chen, Chien-Jen

    2014-01-01

    Hepatitis C virus (HCV) affects 130-210 million people worldwide and is one of the major risk factors for hepatocellular carcinoma. Globally, at least one third of hepatocellular carcinoma cases are attributed to HCV infection, and 350000 people died from HCV related diseases per year. There is a great geographical variation of HCV infection globally, with risk factors for the HCV infection differing in various countries. The progression of chronic hepatitis C to end-stage liver disease also varies in different study populations. A long-term follow-up cohort enrolling participants with asymptomatic HCV infection is essential for elucidating the natural history of HCV-caused hepatocellular carcinoma, and for exploring potential seromarkers that have high predictability for risk of hepatocellular carcinoma. However, prospective cohorts comprising individuals with HCV infection are still uncommon. The risk evaluation of viral load elevation and associated liver disease/cancer in HCV (REVEAL-HCV) study has followed a cohort of 1095 residents seropositive for antibodies against hepatitis C virus living in seven townships in Taiwan for more than fifteen years. Most of them have acquired HCV infection through iatrogenic transmission routes. As the participants in the REVEAL-HCV study rarely receive antiviral therapies, it provides a unique opportunity to study the natural history of chronic HCV infection. In this review, the prevalence, risk factors and natural history of HCV infection are comprehensively reviewed. The study cohort, data collection, and findings on liver disease progression of the REVEAL-HCV study are described. PMID:25071320

  2. Host DNA damage response facilitates African swine fever virus infection.

    PubMed

    Simes, Margarida; Martins, Carlos; Ferreira, Fernando

    2013-07-26

    Studies with different viral infection models on virus interactions with the host cell nucleus have opened new perspectives on our understanding of the molecular basis of these interactions in African swine fever virus (ASFV) infection. The present study aims to characterize the host DNA damage response (DDR) occurring upon in vitro infection with the ASFV-Ba71V isolate. We evaluated protein levels during ASFV time-course infection, of several signalling cascade factors belonging to DDR pathways involved in double strand break repair - Ataxia Telangiectasia Mutated (ATM), ATM-Rad 3 related (ATR) and DNA dependent protein kinase catalytic subunit (DNA-PKcs). DDR inhibitory trials using caffeine and wortmannin and ATR inducible-expression cell lines were used to confirm specific pathway activation during viral infection. Our results show that ASFV specifically elicits ATR-mediated pathway activation from the early phase of infection with increased levels of H2AX, RPA32, p53, ATR and Chk1 phosphorylated forms. Viral p72 synthesis was abrogated by ATR kinase inhibitors and also in ATR-kd cells. Furthermore, a reduction of viral progeny was identified in these cells when compared to the outcome of infection in ATR-wt. Overall, our results strongly suggest that the ATR pathway plays an essential role for successful ASFV infection of host cells. PMID:23398667

  3. Persistent Equine Arteritis Virus Infection in HeLa Cells?

    PubMed Central

    Zhang, Jianqiang; Timoney, Peter J.; MacLachlan, N. James; McCollum, William H.; Balasuriya, Udeni B. R.

    2008-01-01

    The horse-adapted virulent Bucyrus (VB) strain of equine arteritis virus (EAV) established persistent infection in high-passage-number human cervix cells (HeLa-H cells; passages 170 to 221) but not in low-passage-number human cervix cells (HeLa-L cells; passages 95 to 115) or in several other cell lines that were evaluated. However, virus recovered from the 80th passage of the persistently infected HeLa-H cells (HeLa-H-EAVP80) readily established persistent infection in HeLa-L cells. Comparative sequence analysis of the entire genomes of the VB and HeLa-H-EAVP80 viruses identified 16 amino acid substitutions, including 4 in the replicase (nsp1, nsp2, nsp7, and nsp9) and 12 in the structural proteins (E, GP2, GP3, GP4, and GP5). Reverse genetic studies clearly showed that substitutions in the structural proteins but not the replicase were responsible for the establishment of persistent infection in HeLa-L cells by the HeLa-H-EAVP80 virus. It was further demonstrated that recombinant viruses with substitutions in the minor structural proteins E and GP2 or GP3 and GP4 were unable to establish persistent infection in HeLa-L cells but that recombinant viruses with combined substitutions in the E (Ser53?Cys and Val55?Ala), GP2 (Leu15?Ser, Trp31?Arg, Val87?Leu, and Ala112?Thr), GP3 (Ser115?Gly and Leu135?Pro), and GP4 (Tyr4?His and Ile109?Phe) proteins or with a single point mutation in the GP5 protein (Pro98?Leu) were able to establish persistent infection in HeLa-L cells. In summary, an in vitro model of EAV persistence in cell culture was established for the first time. This system can provide a valuable model for studying virus-host cell interactions, especially virus-receptor interactions. PMID:18579588

  4. PREVENTION AND CONTROL OF RETICULOENDOTHELIOSIS VIRUS INFECTION: RATIONALE AND STRATEGIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reticuloendotheliosis virus (REV) is a common retroviral infection of poultry that only rarely causes significant disease problems. Typically, the issue of control is dismissed as unnecessary for and not practiced in commercial flocks. Prevention is a more relevant issue and preventive measures ar...

  5. WEST NILE VIRUS INFECTION IN REINDEER (RANGIFER TARANDUS)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    West Nile virus (WNV) is a mosquito-borne member of the Flaviviridae family (genus Flavivirus) transmitted among bird populations by mosquitoes and incidentally infecting mammals. First recognized in the United States in 1999, WNV has spread across the United States in subsequent years. Numerous cas...

  6. Antibody-Dependent Enhancement of Marburg Virus Infection

    PubMed Central

    Nakayama, Eri; Tomabechi, Daisuke; Matsuno, Keita; Kishida, Noriko; Yoshida, Reiko; Feldmann, Heinz

    2011-01-01

    Background. Marburg virus (MARV) and Ebola virus (EBOV) cause severe hemorrhagic fever in primates. Earlier studies demonstrated that antibodies to particular epitopes on the glycoprotein (GP) of EBOV enhanced virus infectivity in vitro. Methods. To investigate this antibody-dependent enhancement (ADE) in MARV infection, we produced mouse antisera and monoclonal antibodies (mAbs) to the GPs of MARV strains Angola and Musoke. Results. The infectivity of vesicular stomatitis virus pseudotyped with Angola GP in K562 cells was significantly enhanced in the presence of Angola GP antisera, whereas only minimal ADE activity was seen with Musoke GP antisera. This difference correlated with the percentage of hybridoma clones producing infectivity-enhancing mAbs. Using mAbs to MARV GP, we identified 3 distinct ADE epitopes in the mucinlike region on Angola GP. Interestingly, some of these antibodies bound to both Angola and Musoke GPs but showed significantly higher ADE activity for strain Angola. ADE activity depended on epitopes in the mucinlike region and glycine at amino acid position 547, present in the Angola but absent in the Musoke GP. Conclusions. These results suggest a possible link between ADE and MARV pathogenicity and provide new insights into the mechanisms underlying ADE entry of filoviruses. PMID:21987779

  7. 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...

  8. West Nile virus infection among the homeless, Houston, Texas.

    PubMed

    Meyer, Tamra E; Bull, Lara M; Cain Holmes, Kelly; Pascua, Rhia F; Travassos da Rosa, Amelia; Gutierrez, Christian R; Corbin, Tracie; Woodward, Jennifer L; Taylor, Jeffrey P; Tesh, Robert B; Murray, Kristy O

    2007-10-01

    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

  9. Genital ulcers associated with acute Epstein-Barr virus infection.

    PubMed

    Taylor, S; Drake, S M; Dedicoat, M; Wood, M J

    1998-08-01

    To date there have been only five reported cases of females with genital ulceration associated with primary Epstein-Barr virus infection. We describe two further patients and review the clinical features of all seven cases, noting the typical features, particularly purple ulcer margins and systemic symptoms, which should alert the physician to consider this diagnosis. PMID:9924475

  10. Genital ulcers associated with acute Epstein-Barr virus infection

    PubMed Central

    Taylor, S.; Drake, S. M.; Dedicoat, M.; Wood, M. J.

    1998-01-01

    To date there have been only five reported cases of females with genital ulceration associated with primary Epstein-Barr virus infection. We describe two further patients and review the clinical features of all seven cases, noting the typical features, particularly purple ulcer margins and systemic symptoms, which should alert the physician to consider this diagnosis. ??? PMID:9924475

  11. 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

  12. Cytopathological potato virus Y structures during Solanaceous plants infection.

    PubMed

    Otulak, Katarzyna; Garbaczewska, Gra?yna

    2012-07-01

    The ultrastructural analysis of tobacco, potato and pepper tissues during infection with necrotic strains and the ordinary Potato virus Y strain of revealed the presence of virus inclusions not only in the epidermis and mesophyll but also in the vascular tissues. For the first time cytoplasmic inclusions were documented in companion cells and phloem parenchyma as well as in xylem tracheary elements. The ultrastructural features studied in this work consisted of mostly laminated inclusions (in the traverse and longitudinal section), which were frequently connected with enlarged cisternae of endoplasmic reticulum (ER) located in the direct vicinity of the cell wall attached to virus particles opposite to plasmodesmata. It was noticed that ER participates in synthesis and condensation of the PVY inclusions. During compatible interaction of tobacco and potato plants with PVY, amorphous and nuclear inclusions were observed. Such forms were not found in pepper tissues and potato revealing the hypersensitivity reaction to the infection with PVY necrotic strains. It was stated that the forms of cytoplasmic inclusions cannot serve as a cytological criterion to distinguish the potato virus Y strains and do not depend on host resistance level. Only in compatible interaction in Solanaceous plants tissues cytoplasmic inclusions were observed from the moment the morphological symptoms appeared. In the reaction of hypersensitivity, the inclusions were found on the 24th day following the infection with the PVY necrotic strains, whereas the symptoms were observed 3 days after the PVY infection. PMID:22410276

  13. Inhibition of Mayaro virus infection by bovine lactoferrin.

    PubMed

    Carvalho, Carlos A M; Sousa, Ivanildo P; Silva, Jerson L; Oliveira, Andra C; Gonalves, 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

  14. 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...

  15. 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

  16. The mortality of neonatal herpes simplex virus infection.

    PubMed

    Lopez-Medina, Eduardo; Cantey, Joseph B; Snchez, Pablo J

    2015-06-01

    This retrospective study characterized the clinical course of 13 neonates who died with herpes simplex virus infection from 2001 to 2011, representing a 26% case-fatality rate. Fatal disease developed at ? 48 hours of age in one-third of infants, was mostly disseminated disease, and occurred despite early administration of high-dose acyclovir therapy. PMID:25868428

  17. Enterotropic mouse hepatitis virus infection in nude mice.

    PubMed

    Barthold, S W; Smith, A L; Povar, M L

    1985-12-01

    The cause of emaciation and diarrhea in athymic nude mice was found to be hyperplastic typhlocolitis resulting from infection with enterotropic mouse hepatitis virus (MHV). The disease was reproduced in experimentally-inoculated nude mice using intestinal homogenates from affected mice and cell culture-derived virus. Material derived from an experimental mouse was passed into neonatal Swiss mice and caused acute typhlocolitis. Virus failed to grow in NCTC-1469 cells and 17Cl-1 cells, which are normally permissive for MHV, but grew to low titer in a mouse rectal carcinoma cell line, CMT 93. These results show that an enterotropic strain of MHV can cause chronic enteric disease in athymic nude mice. The pattern of infection differs markedly from the more common MHV wasting syndrome in nude mice caused by non-enteric strains of MHV. PMID:3005764

  18. 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

  19. Evidence of Apeu Virus Infection in Wild Monkeys, Brazilian Amazon.

    PubMed

    Oliveira, Danilo B; Luiz, Ana Paula Moreira Franco; Fagundes, Alexandre; Pinto, Carla Amaral; Bonjardim, Cláudio A; Trindade, Giliane S; Kroon, Erna G; Abrahão, Jônatas S; Ferreira, Paulo C P

    2016-03-01

    Orthobunyaviruses are arboviruses in which at least 30 members are human pathogens. The members of group C orthobunyaviruses were first isolated in the Brazilian Amazon in 1950, since that time little information is accumulated about ecology and the medical impact of these virus groups in Brazil. Herein, we describe the evidence of Apeu virus (APEUV; an Orthobunyavirus member) infection in wild monkeys from the Brazilian Amazon forest. APEUV was detected by using a neutralizing antibody in serum and its RNA, suggesting past and acute infection of Amazonian monkeys by this virus. These results altogether represent an important contribution of orthobunyavirus ecology in the Amazon and an update about recent circulation and risk for humans with expansion of the cities to Amazon forest. PMID:26787153

  20. 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 37C. 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

  1. 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

  2. Tioman virus infection in experimentally infected mouse brain and its association with apoptosis.

    PubMed

    Yaiw, Koon Chu; Ong, Kien Chai; Chua, Kaw Bing; Bingham, John; Wang, Linfa; Shamala, Devi; Wong, Kum Thong

    2007-08-01

    Tioman virus is a newly described bat-urine derived paramyxovirus isolated in Tioman Island, Malaysia in 2001. Hitherto, neither human nor animal infection by this virus has been reported. Nonetheless, its close relationship to another paramyxovirus, the Menangle virus which had caused diseases in humans and pigs [Philbey, A.W., Kirkland, P.D., Ross, A.D., Davis, R.J., Gleeson, A.B., Love, R.J., Daniels, P.W., Gould, A.R., Hyatt, A.D., 1998. An apparently new virus (family Paramyxoviridae) infectious for pigs, humans, and fruit bats. Emerg. Infect. Dis. 4, 269-271], raises the possibility that it may be potentially pathogenic. In this study, mice were experimentally infected with Tioman virus by intraperitoneal and intracerebral routes, and the cellular targets and topographical distribution of viral genome and antigens were examined using in situ hybridization and immunohistochemistry, respectively. The possible association between viral infection and apoptosis was also investigated using the TUNEL assay and immunohistochemistry to FasL, Caspase-3, Caspase-8, Caspase-9 and bcl-2. The results showed that Tioman virus inoculated intracerebrally was neurotropic causing plaque-like necrotic areas, and appeared to preferentially replicate in the neocortex and limbic system. Viral infection of inflammatory cells was also demonstrated. TUNEL and Caspase-3 positivity was found in inflammatory cells but not in neurons, while FasL, Caspase-8 and Caspase-9 were consistently negative. This suggests that neuronal infection was associated with necrosis rather than apoptosis. Moreover, the data suggest that there may be an association between viral infection and apoptosis in inflammatory cells, and that it could, at least in part, involve Caspase-independent pathways. Bcl-2 was expressed in some neurons and inflammatory cells indicating its possible role in anti-apoptosis. There was no evidence of central nervous system infection via the intraperitoneal route. PMID:17442409

  3. Differential Sensitivity of Bat Cells to Infection by Enveloped RNA Viruses: Coronaviruses, Paramyxoviruses, Filoviruses, and Influenza Viruses

    PubMed Central

    Hoffmann, Markus; Mller, Marcel Alexander; Drexler, Jan Felix; Glende, Jrg; Erdt, Meike; Gtzkow, Tim; Losemann, Christoph; Binger, Tabea; Deng, Hongkui; Schwegmann-Weels, 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

  4. Association of Inconclusive Sera for Human Immunodeficiency Virus Infection with Malaria and Epstein-Barr Virus Infection in Central Africa

    PubMed Central

    Ndjoyi-Mbiguino, Anglique; Talla, Frdric; Pr, Hlne; Kebe, Khady; Matta, Mathieu; Sosso, Maurice Aurelien; Blec, Laurent

    2014-01-01

    Among 464 sera from adults in Cameroon, 56 (12.1%) gave inconclusive HIV serology. All were negative for HIV-1 DNA; 44.6% (n = 25) were significantly associated with Plasmodium (42.8%) or Epstein-Barr virus (EBV) (17.8%) infections. In Central Africa, sera giving inconclusive results for HIV are frequently associated with malaria, EBV infection, or both. PMID:24478507

  5. Studies on Japanese encephalitis virus infection of reptiles. I. Experimental infection of snakes and lizards.

    PubMed

    Oya, A; Doi, R; Shirasaka, A; Yabe, S; Sasa, M

    1983-04-01

    Experimental infection of four species of snakes, Rhabdophis tigrinus tigrinus, Elaphe quadrivirgata, Elaphe climacophora and Agkistrodon halys, and five species of lizards, Takydromus tachydromoides, Eumeces latiscutatus, Eumeces barbouri, Eumeces marginatus oshimensis and Gekko japonicus, with Japanese encephalitis virus (JEV) was carried out. Evidence of JEV multiplication in snakes was not obtained at least under the conditions used in the present study. All lizards except G. japonicus were infected with JEV by ip injection of virus suspension. The minimum infectious dose for a lizard was around 10(3) MLD50/0.05 ml, and this dose was considered to be proportional to the virus dose which is injected into a host by a vector mosquito at a single bite. Temperature dependence of JE virus growth in the lizards was demonstrated. JEV multiplied slower at 20 degrees C than at 26 degrees C, though the peak titers of viremia were equivalent in both groups of lizards kept at 20 degrees C and 26 degrees C. E. latiscutatus developed viremia with ip injection of a partially attenuated strain, Nakayama NIH which could not infect adult mice by peripheral inoculation. T. tachydromoides and E. latiscutatus were also infected by oral feeding of JEV infected mosquitoes. E. latiscutatus was infected by oral feeding of only one infected mosquito. PMID:6141310

  6. Human Ebola virus infection results in substantial immune activation

    PubMed Central

    McElroy, Anita K.; Akondy, Rama S.; Davis, Carl W.; Ellebedy, Ali H.; Mehta, Aneesh K.; Kraft, Colleen S.; Lyon, G. Marshall; Ribner, Bruce S.; Varkey, Jay; Sidney, John; Sette, Alessandro; Campbell, Shelley; Ströher, Ute; Damon, Inger; Nichol, Stuart T.; Spiropoulou, Christina F.; Ahmed, Rafi

    2015-01-01

    Four Ebola patients received care at Emory University Hospital, presenting a unique opportunity to examine the cellular immune responses during acute Ebola virus infection. We found striking activation of both B and T cells in all four patients. Plasmablast frequencies were 10–50% of B cells, compared with less than 1% in healthy individuals. Many of these proliferating plasmablasts were IgG-positive, and this finding coincided with the presence of Ebola virus-specific IgG in the serum. Activated CD4 T cells ranged from 5 to 30%, compared with 1–2% in healthy controls. The most pronounced responses were seen in CD8 T cells, with over 50% of the CD8 T cells expressing markers of activation and proliferation. Taken together, these results suggest that all four patients developed robust immune responses during the acute phase of Ebola virus infection, a finding that would not have been predicted based on our current assumptions about the highly immunosuppressive nature of Ebola virus. Also, quite surprisingly, we found sustained immune activation after the virus was cleared from the plasma, observed most strikingly in the persistence of activated CD8 T cells, even 1 mo after the patients’ discharge from the hospital. These results suggest continued antigen stimulation after resolution of the disease. From these convalescent time points, we identified CD4 and CD8 T-cell responses to several Ebola virus proteins, most notably the viral nucleoprotein. Knowledge of the viral proteins targeted by T cells during natural infection should be useful in designing vaccines against Ebola virus. PMID:25775592

  7. Antiviral Activity of HPMPC (Cidofovir) Against ORF Virus Infected Lambs

    PubMed Central

    Scagliarini, A.; McInnes, C.J.; Gallina, L.; Dal, Pozzo F.; Scagliarini, L.; Snoeck, R.; Prosperi, S.; Sales, J.; Gilray, J.A.; Nettleton, P.F.

    2007-01-01

    (S)-9-[3-hydroxy-2-(phosphonomethoxy)propyl]-2,6-diaminopurine (HPMPC, cidofovir, CDV, Vistide) is an acyclic nucleoside analogue with a potent and selective activity against a broad spectrum of DNA viruses including the poxviruses. In this study we present the results of different treatment regimens in lambs experimentally infected with orf virus with different cidofovir formulations prepared in Beeler basis and Unguentum M. Our results show that choice of excipient, concentration of cidofovir and treatment regimen were all important to the clinical outcome of the therapy. Whilst one particular regimen appeared to exacerbate the lesion, treatment with 1% w/v cidofovir cream, prepared in Beeler Basis, for 4 consecutive days did result in milder lesions that resolved more quickly than untreated lesions. Furthermore the scabs of the treated animals contained significantly lower amounts of viable virus meaning there should be less contamination of the environment with virus than would normally occur. PMID:17049627

  8. Human Immunodeficiency Virus Infection-Related Heart Disease.

    PubMed

    Pham, Thuy Van; Torres, Mercedes

    2015-08-01

    Human immunodeficiency virus (HIV) infection and antiretroviral medications are independent risk factors for cardiovascular disease. In the pre-antiretroviral therapy (ART) era, HIV-infected patients had increased morbidity and mortality from opportunistic infections; in the post-ART era, these patients are at increased risk of chronic diseases such as acute coronary syndrome, coronary artery disease, cardiac arrhythmias, and cardiomyopathy. They may present with vague symptoms such as weakness, dyspnea, or fatigue as the initial presentation of their cardiovascular disease. An overview of the clinical presentation, workup, management, and treatment of different cardiovascular disease is provided in this article. PMID:26226869

  9. Sweet's syndrome in human immune deficiency virus-infected patient.

    PubMed

    Rajendran, Adarsh; Zacharia, George Sarin; Zacharia, Sue Ann; George, K C

    2014-01-01

    Sweet's syndrome is an uncommon dermatosis and can be associated with a wide variety of illnesses including infections and malignancies. Sweet's syndrome as a dermatological manifestation in human immunedeficiency virus (HIV) infection is rarely reported. Furthermore, called acute febrile neutrophilic dermatosis is characterized by fever and skin lesions, which are often erythematous papules and pseudovesicles. Diagnosis is based on clinical features and histology. The gold standard for treatment is systemic steroids although many other medications have been tried with variable success. We here report a case of Sweet's syndrome in an HIV-infected patient. PMID:26396453

  10. Astrocytic infection in canine distemper virus-induced demyelination.

    PubMed

    Mutinelli, F; Vandevelde, M; Griot, C; Richard, A

    1989-01-01

    Acute canine distemper virus (CDV)-induced demyelinating lesions were examined with double-labelling immunocytochemistry simultaneously demonstrating CDV antigen and glial fibrillary acidid protein (GFAP) as marker for astrocytes. It was shown that 64% of all astrocytes within the demyelinating lesions were infected and that 95% of all infected cells counted in the lesions were astrocytes. These results suggest that the astrocyte is the main target for CDV and that astroglial infection may play an important role in the mechanism of demyelination. PMID:2922996

  11. Immune-mediated Liver Injury in Hepatitis B Virus Infection

    PubMed Central

    Oh, In Soo

    2015-01-01

    Hepatitis B virus (HBV) is responsible for approximately 350 million chronic infections worldwide and is a leading cause of broad-spectrum liver diseases such as hepatitis, cirrhosis and liver cancer. Although it has been well established that adaptive immunity plays a critical role in viral clearance, the pathogenetic mechanisms that cause liver damage during acute and chronic HBV infection remain largely known. This review describes our current knowledge of the immune-mediated pathogenesis of HBV infection and the role of immune cells in the liver injury during hepatitis B. PMID:26330805

  12. 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

  13. Chronic social stress impairs virus specific adaptive immunity during acute Theilers virus infection

    PubMed Central

    Young, Erin E.; Vichaya, Elisabeth G.; Reusser, Nicole M.; Cook, Jennifer L.; Steelman, Andrew R.; Welsh, C. Jane R.; Meagher, Mary W.

    2012-01-01

    Prior exposure to social disruption (SDR) stress exacerbates Theilers murine encephalomyelitis virus (TMEV) infection, a model of multiple sclerosis. Here we examined the impact of SDR on T cell responses to TMEV infection in SJL mice. SDR impaired viral clearance and exacerbated acute disease. Moreover, TMEV infection alone increased CD4 and CD8 mRNA expression in brain and spleen while SDR impaired this response. SDR decreased both CD4+ and CD8+ virus-specific T cells in CNS, but not spleen. These findings suggest that SDR-induced suppression of virus-specific T cell responses contributes to impairments in viral clearance and exacerbation of acute disease. PMID:23021485

  14. Giant DNA virus mimivirus encodes pathway for biosynthesis of unusual sugar 4-amino-4,6-dideoxy-D-glucose (Viosamine).

    PubMed

    Piacente, Francesco; Marin, Margherita; Molinaro, Antonio; De Castro, Cristina; Seltzer, Virginie; Salis, Annalisa; Damonte, Gianluca; Bernardi, Cinzia; Claverie, Jean-Michel; Abergel, Chantal; Tonetti, Michela

    2012-01-27

    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

  15. 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

  16. 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

  17. Persistent infection of human fetal endothelial cells with rubella virus.

    PubMed

    Perelygina, Ludmila; Zheng, Qi; Metcalfe, Maureen; Icenogle, Joseph

    2013-01-01

    Cardiovascular abnormalities are the leading cause of neonatal death among patients with congenital rubella syndrome (CRS). Although persistence of rubella virus (RV) in fetal endothelium has been repeatedly suggested as a possible cause of cardiovascular birth defects, evidence of the permissiveness of fetal endothelial cells to RV is lacking. In this study we evaluated the ability of RV to infect and persist in primary fetal endothelial cells derived from human umbilical vein (HUVEC). We found that wild type (wt) low passage clinical RV productively infected HUVEC cultures without producing cytopathology or ultrastructural changes. RV did not inhibit host cell protein synthesis, cell proliferation, or interfere with the cell cycle. Persistently infected cultures were easily established at low and high multiplicities of infection (MOI) with both laboratory and wt clinical RV strains. However, synchronous infections of entire HUVEC monolayers were only observed with clinical RV strains. The release of infectious virions into media remained at consistently high levels for several subcultures of infected HUVEC. The results indicate that macrovascular fetal endothelial cells are highly permissive to RV and allow slow persistent RV replication. The findings provide more evidence for the suggestion that vascular pathologies in CRS are triggered by persistent rubella virus infection of the endothelium. PMID:23940821

  18. 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

  19. Ultrastructural description of rabies virus infection in cultured sensory neurons.

    PubMed

    Velandia, Myriam L; Prez-Castro, Rosala; Hurtado, Hernn; Castellanos, Jaime E

    2007-06-01

    Primary cultures were made from adult mouse spinal ganglia for depicting an ultrastructural description of rabies virus (RABV) infection in adult mouse sensory neuron cultures; they were infected with rabies virus for 24, 36, and 48 h. The monolayers were processed for transmission electron microscopy and immunochemistry studies at the end of each period. As previously reported, sensory neurons showed great susceptibility to infection by RABV; however, in none of the periods evaluated were assembled virions observed in the cytoplasm or seen to be associated with the cytoplasmic membrane. Instead, fibril matrices of aggregated ribonucleoprotein were detected in the cytoplasm. When infected culture lysate were inoculated into normal animals via intra-cerebral route it was observed that these animals developed clinical symptoms characteristic of infection and transmission electron microscopy revealed assembled virions in the cerebral cortex and other areas of the brain. Sensory neurons infected in vitro by RABV produced a large amount of unassembled viral ribonucleoprotein. However, this intracellular material was able to produce infection and virions on being intra-cerebrally inoculated. It can thus be suggested that the lack of intracellular assembly in sensory neurons forms part of an efficient dissemination strategy. PMID:17612763

  20. Treatment of feline leukemia virus (FeLV) infection.

    PubMed

    Hartmann, K; Block, A; Ferk, G; Beer, B; Vollmar, A; Lutz, H

    1999-09-01

    FeLV infection is still considered to account for most disease-related deaths in pet cats. Different treatment attempts with various drugs were performed in the past but none resulted in healing or complete virus elimination. Therefore, it caused a sensation when Horber and Mayr [Horber, D., Mayr, B., 1991. Prax. 19, 311-314; Horber, D., Schnabl, W., Mayr, B., 1992. Tierarztl. Umschau 47, 556-560; Mayr, B., Horber, D., 1992. Kleintierprax. 37, 515-518] published that they were able to cure 80 to 100% FeLV-infected cats from viremia by using an immunomodulating compound. Articles in cat breeder and cat owner journals appeared assuming that obviously there is a rescue for FeLV-infected cats suffering from this deadly infection. The immunomodulator [Buttner, M., 1993. Comp. Immun. Microbiol. Infect. Dis. 18, 1-10] used in those studies was the so-called 'paramunity inducer' PIND-ORF (Baypamun, Bayer, Leverkusen, Germany) consisting of inactivated parapox ovis virus. Since that time, Baypamun is the most commonly used drug for treatment of FeLV infection in Germany and other European countries. Four placebo-controlled double-blind trials were performed to determine the therapeutic efficacy of Baypamun and other compounds in naturally FeLV-infected cats under controlled conditions. PMID:10515279

  1. 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

  2. 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

  3. The Innate Immune Playbook for Restricting West Nile Virus Infection

    PubMed Central

    Quicke, Kendra M.; Suthar, Mehul S.

    2013-01-01

    West Nile virus (WNV) is an emerging mosquito-borne flavivirus that causes annual epidemics of encephalitic disease throughout the world. Despite the ongoing risk to public health, no approved vaccines or therapies exist for use in humans to prevent or combat WNV infection. The innate immune response is critical for controlling WNV replication, limiting virus-induced pathology, and programming protective humoral and cell-mediated immunity to WNV infection. The RIG-I like receptors, Toll-like receptors, and Nod-like receptors detect and respond to WNV by inducing a potent antiviral defense program, characterized by production of type I IFN, IL-1β and expression of antiviral effector genes. Recent research efforts have focused on uncovering the mechanisms of innate immune sensing, antiviral effector genes that inhibit WNV, and countermeasures employed by WNV to antagonize innate immune cellular defenses. In this review, we highlight the major research findings pertaining to innate immune regulation of WNV infection. PMID:24178712

  4. The innate immune playbook for restricting West Nile virus infection.

    PubMed

    Quicke, Kendra M; Suthar, Mehul S

    2013-11-01

    West Nile virus (WNV) is an emerging mosquito-borne flavivirus that causes annual epidemics of encephalitic disease throughout the world. Despite the ongoing risk to public health, no approved vaccines or therapies exist for use in humans to prevent or combat WNV infection. The innate immune response is critical for controlling WNV replication, limiting virus-induced pathology, and programming protective humoral and cell-mediated immunity to WNV infection. The RIG-I like receptors, Toll-like receptors, and Nod-like receptors detect and respond to WNV by inducing a potent antiviral defense program, characterized by production of type I IFN, IL-1β and expression of antiviral effector genes. Recent research efforts have focused on uncovering the mechanisms of innate immune sensing, antiviral effector genes that inhibit WNV, and countermeasures employed by WNV to antagonize innate immune cellular defenses. In this review, we highlight the major research findings pertaining to innate immune regulation of WNV infection. PMID:24178712

  5. 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

  6. Virus antibody dynamics in primary and secondary dengue infections.

    PubMed

    Gujarati, Tanvi P; Ambika, G

    2014-12-01

    Dengue viral infections show unique infection patterns arising from its four serotypes, (DENV-1,2,3,4). Its effects range from simple fever in primary infections to potentially fatal secondary infections. We analytically and numerically analyse virus dynamics and humoral response in a host during primary and secondary dengue infection for long periods using micro-epidemic models. The models presented here incorporate time delays, antibody dependent enhancement, a dynamic switch and a correlation factor between different DENV serotypes. We find that the viral load goes down to undetectable levels within 7-14 days as is observed for dengue infection, in both cases. For primary infection, the stability analysis of steady states shows interesting dependence on the time delay involved in the production of antibodies from plasma cells. We demonstrate the existence of a critical value for the immune response parameter, beyond which the infection gets completely cured. For secondary infections with a different serotype, the homologous antibody production is enhanced due to the influence of heterologous antibodies. The antibody production is also controlled by the correlation factor, which is a measure of similarities between the different DENV serotypes involved. Our results agree with clinically observed humoral responses for primary and secondary infections. PMID:24384697

  7. 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

  8. 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

  9. Sexual transmission of hepatitis C virus infection.

    PubMed

    Scotto, G; Savastano, A M; Fazio, V; Conte, P E; Ferrara, S; Mangano, A; Tantimonaco, G

    1996-06-01

    The role of sexual transmission in the diffusion of HCV infection, was studied through the seroprevalence of anti-HCV antibodies in the heterosexual habitual partners of 83 anti-HCV positive subjects. The index cases were represented by 10 dialysed subjects, 31 patients with chronic liver disease and 42 healthy carriers. Seroprevalence of anti-HCV positivity reported in partners was 8.43%, with a higher rate in cohabitants of patients with chronic liver disease (16.12% vs 4.76% of carriers); no case was found among partners of dialysed subjects Laboratory and ultrasonograph signs of chronic hepatitis were reported in 3 cases (3.61%). Control on 70% of the cohabitants' relatives, was negative for HCV infections. These data suggest a possible sexual transmission of HCV infection, even if its prevalence resulted modest, undoubtedly lower than in other disease sexually transmitted. PMID:8884190

  10. Dermatological manifestations of hepatitis C virus infection in Saudi Arabia.

    PubMed

    Halawani, Mona R

    2014-06-01

    The Saudi Ministry of Health data indicates that almost 32% of viral hepatitis cases were caused by hepatitis C virus (HCV). It has been widely reported that chronic HCV infection is associated with and may trigger or exacerbate many skin manifestations in 20-40% of patients visiting dermatologists. The most commonly encountered dermatological manifestations of HCV infection globally include mixed cryoglobulinemia, porphyria cutanea tarda, cutaneous and/or oral lichen planus, urticaria, pruritus, thrombocytopenic purpura, and psoriasis. The current article indicates that HCV infection is increasing in Saudi Arabia and approximately 12% of the reported dermatological manifestations are caused by HCV infection. We recommend the urgent need for large-scale, case-control studies to understand the impact of HCV infection in patients with skin disease. PMID:24888650

  11. Antiviral activity of ginseng extract against respiratory syncytial virus infection

    PubMed Central

    LEE, JONG SEOK; KO, EUN-JU; HWANG, HYE SUK; LEE, YU-NA; KWON, YOUNG-MAN; KIM, MIN-CHUL; KANG, SANG-MOO

    2014-01-01

    Panax ginseng has been known to have a number of immuno-modulatory effects. In this study, we investigated whether Panax Korean red ginseng extract (KRGE) has in vitro and in vivo antiviral effects on respiratory syncytial virus (RSV) infection. KRGE improved the survival of human lung epithelial cells against RSV infection and inhibited RSV replication. In addition, KRGE treatment suppressed the expression of RSV-induced inflammatory cytokine genes (IL-6 and IL-8) and the formation of reactive oxygen species in epithelial cell cultures. Oral administration of mice with KRGE resulted in lowering lung viral loads after RSV infection. Additionally, the in vivo effects of KRGE showed an enhanced level of interferon-γ (IFN-γ) producing dendritic cells subsequent to RSV infection. Taken together, these results suggested that KRGE has antiviral activity against RSV infection. PMID:24756136

  12. Evidence that a plant virus switched hosts to infect a vertebrate and then recombined with a vertebrate-infecting virus

    PubMed Central

    Gibbs, Mark J.; Weiller, Georg F.

    1999-01-01

    There are several similarities between the small, circular, single-stranded-DNA genomes of circoviruses that infect vertebrates and the nanoviruses that infect plants. We analyzed circovirus and nanovirus replication initiator protein (Rep) sequences and confirmed that an N-terminal region in circovirus Reps is similar to an equivalent region in nanovirus Reps. However, we found that the remaining C-terminal region is related to an RNA-binding protein (protein 2C), encoded by picorna-like viruses, and we concluded that the sequence encoding this region of Rep was acquired from one of these single-stranded RNA viruses, probably a calicivirus, by recombination. This is clear evidence that a DNA virus has incorporated a gene from an RNA virus, and the fact that none of these viruses code for a reverse transcriptase suggests that another agent with this capacity was involved. Circoviruses were thought to be a sister-group of nanoviruses, but our phylogenetic analyses, which take account of the recombination, indicate that circoviruses evolved from a nanovirus. A nanovirus DNA was transferred from a plant to a vertebrate. This transferred DNA included the viral origin of replication; the sequence conservation clearly indicates that it maintained the ability to replicate. In view of these properties, we conclude that the transferred DNA was a kind of virus and the transfer was a host-switch. We speculate that this host-switch occurred when a vertebrate was exposed to sap from an infected plant. All characterized caliciviruses infect vertebrates, suggesting that the host-switch happened first and that the recombination took place in a vertebrate. PMID:10393941

  13. 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.

  14. Specific human cytotoxic T cells recognize B-cell lines persistently infected with respiratory syncytial virus.

    PubMed Central

    Bangham, C R; McMichael, A J

    1986-01-01

    The T-lymphocyte response to respiratory syncytial (RS) virus has been invoked to explain the bronchiolitis and pneumonia caused by RS virus in human infants. However, T cells also appear to play a role in protection against RS virus infection. Although RS virus-specific human lymphocytes have been demonstrated, neither the phenotype nor the function of the lymphocytes was characterized. We describe here the induction of anti-RS virus cytotoxic T lymphocytes, in both bulk culture and restimulated cell lines, from human peripheral blood. Infection of Epstein-Barr virus-transformed human B-cell lines with RS virus in vitro readily caused a persistent infection; these cells continued to synthesize RS viral proteins and secrete infectious RS virus 4 months after infection. The persistently infected cells were used both to restimulate cytotoxic-T-cell precursors and as targets for RS virus-specific cytotoxic T cells. Images PMID:3097646

  15. 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

  16. Health care-associated hepatitis C virus infection.

    PubMed

    Pozzetto, Bruno; Memmi, Meriam; Garraud, Olivier; Roblin, Xavier; Berthelot, Philippe

    2014-12-14

    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

  17. 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

  18. 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

  19. Dynamics of influenza A virus infections in permanently infected pig farms: evidence of recurrent infections, circulation of several swine influenza viruses and reassortment events

    PubMed Central

    2013-01-01

    Concomitant infections by different influenza A virus subtypes within pig farms increase the risk of new reassortant virus emergence. The aims of this study were to characterize the epidemiology of recurrent swine influenza virus infections and identify their main determinants. A follow-up study was carried out in 3 selected farms known to be affected by repeated influenza infections. Three batches of pigs were followed within each farm from birth to slaughter through a representative sample of 40 piglets per batch. Piglets were monitored individually on a monthly basis for serology and clinical parameters. When a flu outbreak occurred, daily virological and clinical investigations were carried out for two weeks. Influenza outbreaks, confirmed by influenza A virus detection, were reported at least once in each batch. These outbreaks occurred at a constant age within farms and were correlated with an increased frequency of sneezing and coughing fits. H1N1 and H1N2 viruses from European enzootic subtypes and reassortants between viruses from these lineages were consecutively and sometimes simultaneously identified depending on the batch, suggesting virus co-circulations at the farm, batch and sometimes individual levels. The estimated reproduction ratio R of influenza outbreaks ranged between 2.5 [1.9-2.9] and 6.9 [4.1-10.5] according to the age at infection-time and serological status of infected piglets. Duration of shedding was influenced by the age at infection time, the serological status of the dam and mingling practices. An impaired humoral response was identified in piglets infected at a time when they still presented maternally-derived antibodies. PMID:24007505

  20. A novel integrase-containing element may interact with Laem-Singh virus (LSNV) to cause slow growth in giant tiger shrimp

    PubMed Central

    2011-01-01

    Background From 2001-2003 monodon slow growth syndrome (MSGS) caused severe economic losses for Thai shrimp farmers who cultivated the native, giant tiger shrimp, and this led them to adopt exotic stocks of the domesticated whiteleg shrimp as the species of cultivation choice, despite the higher value of giant tiger shrimp. In 2008, newly discovered Laem-Singh virus (LSNV) was proposed as a necessary but insufficient cause of MSGS, and this stimulated the search for the additional component cause(s) of MSGS in the hope that discovery would lead to preventative measures that could revive cultivation of the higher value native shrimp species. Results Using a universal shotgun cloning protocol, a novel RNA, integrase-containing element (ICE) was found in giant tiger shrimp from MSGS ponds (GenBank accession number FJ498866). In situ hybridization probes and RT-PCR tests revealed that ICE and Laem-Singh virus (LSNV) occurred together in lymphoid organs (LO) of shrimp from MSGS ponds but not in shrimp from normal ponds. Tissue homogenates of shrimp from MSGS ponds yielded a fraction that gave positive RT-PCR reactions for both ICE and LSNV and showed viral-like particles by transmission electron microscopy (TEM). Bioassays of this fraction with juvenile giant tiger shrimp resulted in retarded growth with gross signs of MSGS, and in situ hybridization assays revealed ICE and LSNV together in LO, eyes and gills. Viral-like particles similar to those seen in tissue extracts from natural infections were also seen by TEM. Conclusions ICE and LSNV were found together only in shrimp from MSGS ponds and only in shrimp showing gross signs of MSGS after injection with a preparation containing ICE and LSNV. ICE was never found in the absence of LSNV although LSNV was sometimes found in normal shrimp in the absence of ICE. The results suggest that ICE and LSNV may act together as component causes of MSGS, but this cannot be proven conclusively without single and combined bioassays using purified preparations of both ICE and LSNV. Despite this ambiguity, it is recommended in the interim that ICE be added to the agents such as LSNV already listed for exclusion from domesticated stocks of the black tiger shrimp. PMID:21569542

  1. Hepatitis B Virus / Human Immunodeficiency Virus Co-Infection and Its Hepatocarcinogenic Potential in Sub-Saharan Black Africans

    PubMed Central

    Kew, Michael C.

    2012-01-01

    Context Since the introduction of highly active anti-retroviral regimen for human immunodeficiency virus-1 infection, a significant increase in the incidence of hepatocellular carcinoma has been reported in patients already chronically infected with hepatitis B virus and then given this form of regimen for their retroviral infection. Evidence Acquisition This phenomenon was initially attributed to the far more prolonged survival of those patients who received this new regimen, which provided sufficient time, allowing hepatitis B virus-induced hepatocellular carcinoma to develop. Results The current belief is that the increased incidence of hepatocellular carcinoma is because of co-infection with the two viruses, one known to be hepatocarcinogenic and the other suspected to increase the carcinogenic potential of the other. Because both hepatitis B virus and human immunodeficiency virus -1 are endemic in the Black population of sub-Saharan Africa and are transmitted in similar ways, as many as 20% of this population are co-infected with the two viruses. In this way, the already high risk of Black African patients developing hepatitis B virus-induced hepatocellular carcinoma is further increased. Conclusions The pathogenetic mechanism or mechanisms involved in the carcinogenic interaction between the hepatitis B virus and the human immunodeficiency virus-1 in sub-Saharan Black Africans and other populations co-infected with these viruses have yet to be determined. PMID:23166538

  2. Detection of virus-specific antigen in the nuclei or nucleoli of cells infected with Zika or Langat virus.

    PubMed

    Buckley, A; Gould, E A

    1988-08-01

    Two monoclonal antibodies (MAbs) with molecular specificities for either the viral envelope glycoprotein (MAb 541) or the non-structural NS1 glycoprotein (MAb 109) were derived using West Nile and yellow fever (YF) viruses respectively. Their antigenic reactivity with a large number of flaviviruses was tested by indirect immunofluorescence microscopy. Both produced cytoplasmic fluorescent staining patterns with the homologous virus against which they were raised. Additionally, MAb 541 reacted with two substrains of YF virus whereas MAb 109 reacted with Bussuquara, YF and Ntaya viruses. These reactions were exclusively cytoplasmic. Two unexpected patterns of fluorescent labelling were observed when the antibodies were tested with Zika and Langat viruses. MAb 541 produced fluorescent staining of the nuclei, but not the cytoplasm, of cells infected with Zika virus and MAb 109 labelled only the nucleoli of cells infected with Langat virus. Double-labelling experiments showed that the nuclear fluorescent label was confined to virus-infected cells, and antibody absorption experiments with virus-infected cell packs confirmed the virus specificity of the nuclear antigen. The unexpected presence of virus-specific antigen in the nuclei or nucleoli of Zika or Langat virus-infected cells brings into question the role of the nucleus in flavivirus replication. PMID:2841406

  3. [Innate immune response to RNA virus infection].

    PubMed

    Oshiumi, Hiroyuki; Matsumoto, Misako; Seya, Tsukasa

    2011-12-01

    Viral RNA is recognized by RIG-I-like receptors and Toll-like receptors. RIG-I is a cytoplasmic viral RNA sensor. High Mobility Group Box (HMGB) proteins and DExD/H box RNA helicases, such as DDX3 and 60, associate with viral RNA. Those proteins promotes the RIG-I binding to viral RNA. RIG-I triggers the signal via IPS-1 adaptor molecule to induce type I IFN. RIG-I harbors Lys63-linked polyubiquitination by Riplet and TRIM25 ubiquitin ligases. The polyubiquitination is essential for RIG-I-mediated signaling. Toll-like receptors are located in endosome. TLR3 recognizes viral double-stranded RNA, and TLR7 and 8 recognize single-strand RNA. Virus has the ability to suppress these innate immune response. For example, to inhibit RIG-I-mediated signaling, HCV core protein suppresses the function of DDX3. In addition, HCV NS3-4A protein cleaves IPS-1 to inhibit the signal. Molecular mechanism of how viral RNA is recognized by innate immune system will make great progress on our understanding of how virus escapes from host immune system. PMID:22916562

  4. 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

  5. Deviatoric stressitis: A virus infecting the Earth science community

    NASA Astrophysics Data System (ADS)

    Engelder, Terry

    This note serves as a warning that a recently mutated virus, deviatoric stressitis, has infected many in the Earth science community. The good news is that this virus, nicknamed deveitis (dee vee' i-tis), is not lethal and its victims can hope for a complete recovery. The bad news is that deveitis has spread like wildfire and leads to great confusion about Earth stress in papers, abstracts, and discussions by any of its victims.Deveitis is easy to recognize. The most common symptom is the use of the term, deviatoric stress, in papers, abstracts, and discussions.

  6. Acute infection of encephalomyocarditis (EMC) virus in Syrian hamsters.

    PubMed

    Sugawara, Y; Hirasawa, K; Takeda, M; Han, J S; Doi, K

    1991-06-01

    One-month-old Syrian hamsters of the APA and Std: golden strains were inoculated intraperitoneally with 10(5) PFU/head of the D variant of encephalomyocarditis (EMC) virus and examined virologically and pathologically up to 7 days after inoculation. APA hamsters developed apparent hyperglycemia due to pancreatic islet cell damage while Std:golden hamsters did not. Hamsters of both strains showed clear histopathologic changes in the testis with prominent viral replication as well as in the brain, heart and exocrine pancreas. The susceptibility to EMC virus-infection was higher in males than in females and in APA than in Std: golden hamsters. PMID:1653039

  7. 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

  8. Naturally Occurring Animal Models of Human Hepatitis E Virus Infection

    PubMed Central

    Yugo, Danielle M.; Cossaboom, Caitlin M.; Meng, Xiang-Jin

    2014-01-01

    Hepatitis E virus (HEV) is a single-stranded, positive-sense RNA virus in the family Hepeviridae. Hepatitis E caused by HEV is a clinically important global disease. There are currently four well-characterized genotypes of HEV in mammalian species, although numerous novel strains of HEV likely belonging to either new genotypes or species have recently been identified from several other animal species. HEV genotypes 1 and 2 are limited to infection in humans, whereas genotypes 3 and 4 infect an expanding host range of animal species and are zoonotic to humans. Historical animal models include various species of nonhuman primates, which have been indispensable for the discovery of human HEV and for understanding its pathogenesis and course of infection. With the genetic identification and characterization of animal strains of HEV, a number of naturally occurring animal models such as swine, chicken, and rabbit have recently been developed for various aspects of HEV research, including vaccine trials, pathogenicity, cross-species infection, mechanism of virus replication, and molecular biology studies. Unfortunately, the current available animal models for HEV are still inadequate for certain aspects of HEV research. For instance, an animal model is still lacking to study the underlying mechanism of severe and fulminant hepatitis E during pregnancy. Also, an animal model that can mimic chronic HEV infection is critically needed to study the mechanism leading to chronicity in immunocompromised individuals. Genetic identification of additional novel animal strains of HEV may lead to the development of better naturally occurring animal models for HEV. This article reviews the current understanding of animal models of HEV infection in both natural and experimental infection settings and identifies key research needs and limitations. PMID:24936039

  9. Oligodendroglial pathology in canine distemper virus infection in vitro.

    PubMed

    Zurbriggen, A; Vandevelde, M; Dumas, M; Griot, C; Bollo, E

    1987-01-01

    Dog brain cell cultures were infected with different canine distemper virus (CDV) strains to study the oligodendrocytes, which were characterized with eight different antibodies to cover the whole oligodendroglial population in the culture. A few weeks after infection all oligodendroglial cell types started to degenerate and disappeared from the culture. However, since no CDV protein could be demonstrated in the degenerating oligodendrocytes with extensive double-labelling studies, this lesion can not be explained as being a result of cytolytic infection. This conclusion was further supported in experiments with plaque-forming CDV, in which viral replication is restricted to the cytolytic areas only; oligodendrocytes also degenerated in virus-free areas between the plaques. The hypothesis of toxic factors released by other infected cell types in the culture leading to secondary damage of the oligodendrocyte could not be confirmed by transferring supernatants from infected to normal cultures. Whereas the presence of toxic factors can not be completely excluded, the possibility of an abortive infection of the oligodendrocytes with no or very limited viral protein synthesis is discussed. PMID:3687388

  10. Multiple roles of the coagulation protease cascade during virus infection

    PubMed Central

    Antoniak, Silvio

    2014-01-01

    The coagulation cascade is activated during viral infections. This response may be part of the host defense system to limit spread of the pathogen. However, excessive activation of the coagulation cascade can be deleterious. In fact, inhibition of the tissue factor/factor VIIa complex reduced mortality in a monkey model of Ebola hemorrhagic fever. Other studies showed that incorporation of tissue factor into the envelope of herpes simplex virus increases infection of endothelial cells and mice. Furthermore, binding of factor X to adenovirus serotype 5 enhances infection of hepatocytes but also increases the activation of the innate immune response to the virus. Coagulation proteases activate protease-activated receptors (PARs). Interestingly, we and others found that PAR1 and PAR2 modulate the immune response to viral infection. For instance, PAR1 positively regulates TLR3-dependent expression of the antiviral protein interferon ?, whereas PAR2 negatively regulates expression during coxsackievirus group B infection. These studies indicate that the coagulation cascade plays multiple roles during viral infections. PMID:24632711

  11. Neuropathogenesis of persistent infection with Borna disease virus.

    PubMed

    Honda, Tomoyuki

    2015-01-01

    Borna disease virus (BDV), belonging to the non-segmented, negative-stranded RNA viruses, persistently infects the central nervous system of many mammals. Neonatal BDV infection in rodent models induces neurodevelopmental disturbance without overt inflammatory responses, resulting in a wide range of neurobehavioral abnormalities, such as anxiety, abnormal play behaviors, and cognitive deficits, resembling those of autism patients. Therefore, studies of BDV could provide a valuable model to investigate neuropathogenesis of neurodevelopmental disorders. However, the detailed neuropathogenesis of BDV has not been revealed. Here, we proposed two novel mechanisms that may contribute to BDV neuropathology. The first mechanism is abnormal IGF signaling. Using transgenic mice expressing BDV P protein in glial cells (P-Tg) that show neurobehavioral abnormalities resembling those in BDV-infected animals, we found that the upregulation of insulin-like growth factor (IGF) binding protein 3 in the astrocytes disturbs the IGF signaling and induces the Purkinje cell loss in BDV infection. The other is the integration of BDV sequences into the host genome. We recently found that BDV mRNAs are reverse-transcribed and integrated into the genome of infected cells. BDV integrants have the potential to produce their translated products or piRNAs, suggesting that BDV might exhibit the pathogenicity thorough these molecules. We also demonstrated that BDV integrants affect neighboring gene expression. Collectively, BDV integrants may alter transcriptome of infected cells, affecting BDV neuropathology. PMID:26923969

  12. Immunophenotypical characterization of monocytes in canine distemper virus infection.

    PubMed

    Stein, Veronika M; Schreiner, Nicole M S; Moore, Peter F; Vandevelde, Marc; Zurbriggen, Andreas; Tipold, Andrea

    2008-10-15

    Canine distemper virus (CDV) infection induces multifocal demyelination in the central nervous system (CNS). It is thought that the resident macrophages of the CNS, the microglia, as well as invading monocytes associated with the inflammatory reaction may play a central role in the demyelinating process. To evaluate changes in peripheral monocytes in CDV infection their immunophenotype was characterized by flow cytometry during the course of an experimental CDV infection in dogs. The highest number of CDV-infected monocytes was found in dogs developing demyelinating lesions. In CD18, CD45, CD44, and CD14 neither up- nor down-regulation was observed. Marked up-regulation occurred in a number of surface molecules including CD1c, B7-1 and B7-2, MHC I, and CD11b. Peak expression was found at 4-5 weeks post-infection (PI), regardless of clinical outcome. All these molecules play an important role in the host's immune response, notably antigen presentation and cell adhesion. These results demonstrate that CDV infection in vivo may enhance several macrophage functions. This could lead to more effective clearance of the virus but may also increase demyelination through a bystander effect in animals that accumulated significant amounts of CDV in the CNS. PMID:18472370

  13. Virus evolution during chronic hepatitis B virus infection as revealed by ultradeep sequencing data.

    PubMed

    Jones, Leandro R; Sede, Mariano; Manrique, Julieta M; Quarleri, Jorge

    2016-02-01

    Despite chronic hepatitis B virus (HBV) infection (CHB) being a leading cause of liver cirrhosis and cancer, HBV evolution during CHB is not fully understood. Recent studies have indicated that virus diversity progressively increases along the course of CHB and that some virus mutations correlate with severe liver conditions such as chronic hepatitis, cirrhosis and hepatocellular carcinoma. Using ultradeep sequencing (UDS) data from an intrafamilial case, we detected such mutations at low frequencies among three immunotolerant patients and at high frequencies in an inactive carrier. Furthermore, our analyses indicated that the HBV population from the seroconverter patient underwent many genetic changes in response to virus clearance. Together, these data indicate a potential use of UDS for developing non-invasive biomarkers for monitoring disease changes over time or in response to specific therapies. In addition, our analyses revealed that virus clearance seemed not to require the virus effective population size to decline. A detailed genetic analysis of the viral lineages arising during and after the clearance suggested that mutations at or close to critical elements of the core promoter (enhancer II, epsilon encapsidation signal, TA2, TA3 and direct repeat 1-hormone response element) might be responsible for a sustained replication. This hypothesis requires the decline in virus load to be explained by constant clearance of virus-producing hepatocytes, consistent with the sustained progress towards serious liver conditions experienced by many CHB patients. PMID:26581478

  14. Challenges in managing hepatitis C virus infection in cancer patients.

    PubMed

    Borchardt, Roy A; Torres, Harrys A

    2014-03-21

    Cancer patients have unique problems associated with hepatitis C virus (HCV) infection and treatment not seen in the general population. HCV infection poses additional challenges and considerations for the management of cancer, and vice versa. HCV infection also can lead to the development of cancer, particularly hepatocellular carcinoma and non-Hodgkin lymphoma. In severely immunocompromised cancer patients, diagnosis of HCV infection requires increased reliance on RNA detection techniques. HCV infection can affect chemotherapy, and delay of HCV infection treatment until completion of chemotherapy and achievement of cancer remission may be required to decrease the potential for drug-drug interactions between antineoplastic agents and HCV therapeutics and potentiation of side effects of these agents. In addition, hematopoietic stem cell transplant (HSCT) recipients have an increased risk of early development of cirrhosis and fibrosis. Whether this increased risk applies to all patients regardless of cancer treatment is unknown. Furthermore, patients with cancer may have poorer sustained virological responses to HCV infection treatment than do those without cancer. Unfortunately, not all cancer patients are candidates for HCV infection therapy. In this article, we review the challenges in managing HCV infection in cancer patients and HSCT recipients. PMID:24659870

  15. Experimental Lassa virus infection in the squirrel monkey.

    PubMed Central

    Walker, D. H.; Wulff, H.; Murphy, F. A.

    1975-01-01

    Experimental Lassa virus infection was investigated in a nonhuman primate in order to elucidate the target organs of the viral infection and the course of pathologic events. Four squirrel monkeys (Saimiri scirreus) were inoculated intramuscularly with Lassa virus and sacrificed for organ titrations and histopathology, one each day, on Days 7, 12, 14, and 28 after inoculation. The animals showed a variable clinical course, with an incubation period of 8 to 18 days. The virus was demonstrated to be virtually pantropic; however, lymph node, liver, and kidney were key early targets. After the onset of overt disease, patterns of lymphoreticulotropism, hepatotropism, nephrotropism, adrenotropism, and persistent viremia were evident. Complement-fixing antibody failed to develop after 28 days of infection. Histopathologic findings included germinal center necrosis in spleen and lymph node; myocarditis; acute arteritis; renal tubular necrosis and regeneration; hepatocytic regeneration; chronic inflammation of choroid plexus, ependyma, and meninges; and cerebral perivascular cuffing. There is a relationship between many of these lesions and certain features of other arenavirus infections. The model offers the opportunity to pursue investigations of experimental pathogenesis, transmissibility, and efficacy of immunotherapy. Images Figure 1 Figure 2 Figure 9 Figure 10 Figure 11 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 PMID:1163630

  16. Chayote mosaic virus, a New Tymovirus Infecting Cucurbitaceae.

    PubMed

    Bernal, J J; Jiménez, I; Moreno, M; Hord, M; Rivera, C; Koenig, R; Rodríguez-Cerezo, E

    2000-10-01

    ABSTRACT Chayote mosaic virus (ChMV) is a putative tymovirus isolated from chayote crops in Costa Rica. ChMV was characterized at the host range, serological, and molecular levels. ChMV was transmitted mechanically and induced disease symptoms mainly in Cucurbitaceae hosts. Asymptomatic infections were detected in other host families. Serologically, ChMV is related to the Andean potato latent virus (APLV) and the Eggplant mosaic virus (EMV), both members of the genus Tymovirus infecting solanaceous hosts in the Caribbean Basin and South America. The sequence of the genomic RNA of ChMV was determined and its genetic organization was typical of tymoviruses. Comparisons with other tymoviral sequences showed that ChMV was a new member of the genus Tymovirus. The phylogenetic analyses of the coat protein gene were consistent with serological comparisons and positioned ChMV within a cluster of tymoviruses infecting mainly cucurbit or solanaceous hosts, including APLV and EMV. Phylogenetic analyses of the replicase protein gene confirmed the close relationship of ChMV and EMV. Our results suggest that ChMV is related to two tymoviruses (APLV and EMV) of proximal geographical provenance but with different natural host ranges. ChMV is the first cucurbit-infecting tymovirus to be fully characterized at the genomic level. PMID:18944472

  17. Inhibition of Bim Enhances Replication of Varicella-Zoster Virus and Delays Plaque Formation in Virus-Infected Cells

    PubMed Central

    Liu, XueQiao

    2014-01-01

    Programmed cell death (apoptosis) is an important host defense mechanism against intracellular pathogens, such as viruses. Accordingly, viruses have evolved multiple mechanisms to modulate apoptosis to enhance replication. Varicella-zoster virus (VZV) induces apoptosis in human fibroblasts and melanoma cells. We found that VZV triggered the phosphorylation of the proapoptotic proteins Bim and BAD but had little or no effect on other Bcl-2 family members. Since phosphorylation of Bim and BAD reduces their proapoptotic activity, this may prevent or delay apoptosis in VZV-infected cells. Phosphorylation of Bim but not BAD in VZV-infected cells was dependent on activation of the MEK/extracellular signal-regulated kinase (ERK) pathway. Cells knocked down for Bim showed delayed VZV plaque formation, resulting in longer survival of VZV-infected cells and increased replication of virus, compared with wild-type cells infected with virus. Conversely, overexpression of Bim resulted in earlier plaque formation, smaller plaques, reduced virus replication, and increased caspase 3 activity. Inhibition of caspase activity in VZV-infected cells overexpressing Bim restored levels of virus production similar to those seen with virus-infected wild-type cells. Previously we showed that VZV ORF12 activates ERK and inhibits apoptosis in virus-infected cells. Here we found that VZV ORF12 contributes to Bim and BAD phosphorylation. In summary, VZV triggers Bim phosphorylation; reduction of Bim levels results in longer survival of VZV-infected cells and increased VZV replication. PMID:24227856

  18. Glycosaminoglycan Sulfation Requirements for Respiratory Syncytial Virus Infection

    PubMed Central

    Hallak, Louay K.; Spillmann, Dorothe; Collins, Peter L.; Peeples, Mark E.

    2000-01-01

    Glycosaminoglycans (GAGs) on the surface of cultured cells are important in the first step of efficient respiratory syncytial virus (RSV) infection. We evaluated the importance of sulfation, the major biosynthetic modification of GAGs, using an improved recombinant green fluorescent protein-expressing RSV (rgRSV) to assay infection. Pretreatment of HEp-2 cells with 50 mM sodium chlorate, a selective inhibitor of sulfation, for 48 h prior to inoculation reduced the efficiency of rgRSV infection to 40%. Infection of a CHO mutant cell line deficient in N-sulfation was three times less efficient than infection of the parental CHO cell line, indicating that N-sulfation is important. In contrast, infection of a cell line deficient in 2-O-sulfation was as efficient as infection of the parental cell line, indicating that 2-O-sulfation is not required for RSV infection. Incubating RSV with the purified soluble heparin, the prototype GAG, before inoculation had previously been shown to neutralize its infectivity. Here we tested chemically modified heparin chains that lack their N-, C6-O-, or C2-O-sulfate groups. Only heparin chains lacking the N-sulfate group lost the ability to neutralize infection, confirming that N-sulfation, but not C6-O- or C2-O-sulfation, is important for RSV infection. Analysis of heparin fragments identified the 10-saccharide chain as the minimum size that can neutralize RSV infectivity. Taken together, these results show that, while sulfate modification is important for the ability of GAGs to mediate RSV infection, only certain sulfate groups are required. This specificity indicates that the role of cell surface GAGs in RSV infection is not based on a simple charge interaction between the virus and sulfate groups but instead involves a specific GAG structural configuration that includes N-sulfate and a minimum of 10 saccharide subunits. These elements, in addition to iduronic acid demonstrated previously (L. K. Hallak, P. L. Collins, W. Knudson, and M. E. Peeples, Virology 271:264275, 2000), partially define cell surface molecules important for RSV infection of cultured cells. PMID:11044095

  19. Hepatitis C virus (HCV) core serotypes in chronic HCV infection.

    PubMed Central

    Mondelli, M U; Cerino, A; Bono, F; Cividini, A; Maccabruni, A; Aric, M; Malfitano, A; Barbarini, G; Piazza, V; Minoli, L

    1994-01-01

    Recently, two distinct hepatitis C virus (HCV) serologic types have been identified on the basis of amino acid variations in the core region. The two serologic types can readily discriminate between genotypes I-II-V (serotype 1) and III-IV (serotype 2), according to the Okamoto classification. We compared HCV core serotyping with genotyping with sera from 363 anti-HCV-positive patients (309 HCV RNA positive by PCR) using a synthetic core peptide-based enzyme immunoassay and PCR amplification of core region sequences with type-specific primers, respectively. Serologic responses to HCV serotypes were successfully identified in 164 (45%) patients, of whom 153 were viremic. Eighty-nine patients had evidence of exposure to serotype 1: 8 of these were infected with genotype I, 50 were infected with genotype II, 2 were infected with genotype III, 7 were infected with genotype V, 13 had infections with mixed genotypes, 3 were infected with an indeterminate genotype, and 6 were nonviremic. Seventy-four patients had been exposed to serotype 2: 64 were infected with genotype III, 3 were infected with mixed genotypes, 2 were infected with an indeterminate genotype, and 5 were nonviremic. The serum of one patient, infected with genotype III, showed reactivity to both serotypes. Comparative evaluation of HCV core region serotyping and genotyping with sera from 294 viremic patients infected with a known HCV genotype showed a remarkable concordance between HCV core region genotyping and serotyping, with only 2 apparently discordant serum samples (both from patients with genotype III infection) of 148 (1.4%) successfully serotyped samples. Serotype 1 infection was more frequently observed in patients with overt chronic liver disease and accounted for all successfully serotyped samples from intravenous drug abusers. In contrast, serotype 2 was more prevalent in subjects with biochemically silent HCV infection (alanine aminotransferase, < 45 U/liter), in agreement with previous findings at the molecular level. HCV core serologic typing is a simple, inexpensive, and highly reproducible assay that can be applied to more than 50% of viremic HCV antibody carriers prior to the use of more sophisticated molecular typing techniques. Moreover, it may be helpful in tracking transmissions routes, particularly for incorrectly stored samples in which the RNA has degraded or for subjects who have cleared the virus and therefore have only antibodies remaining to testify to a remote infection. The lack of recognition of the core sequence from residues 67 to 81, which contains a minor B-cell epitope used to detect type-specific immunoreactivity, may explain the negative serologic findings for half of the patients. PMID:7814491

  20. NF-kappaB and virus infection: who controls whom.

    PubMed

    Santoro, M Gabriella; Rossi, Antonio; Amici, Carla

    2003-06-01

    Among the different definitions of viruses, 'pirates of the cell' is one of the most picturesque, but also one of the most appropriate. Viruses have been known for a long time to utilize a variety of strategies to penetrate cells and, once inside, to take over the host nucleic acid and protein synthesis machinery to build up their own components and produce large amounts of viral progeny. As their genomes carry a minimal amount of information, encoding only a few structural and regulatory proteins, viruses are largely dependent on their hosts for survival; however, despite their apparent simplicity, viruses have evolved different replicative strategies that are regulated in a sophisticated manner. During the last years, the study of the elaborate relationship between viruses and their hosts has led to the understanding of how viral pathogens not only are able to alter the host metabolism via their signaling proteins, but are also able to hijack cellular signaling pathways and transcription factors, and control them to their own advantage. In particular, the nuclear factor-kappaB (NF-kappaB) pathway appears to be an attractive target for common human viral pathogens. This review summarizes what is known about the control of NF-kappaB by viruses, and discusses the possible outcome of NF-kappaB activation during viral infection, which may benefit either the host or the pathogen. PMID:12773372

  1. 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

  2. Temporal Analysis of Andes Virus and Sin Nombre Virus Infections of Syrian Hamsters?

    PubMed Central

    Wahl-Jensen, Victoria; Chapman, Jennifer; Asher, Ludmila; Fisher, Robert; Zimmerman, Michael; Larsen, Tom; Hooper, Jay W.

    2007-01-01

    Andes virus (ANDV) and Sin Nombre virus (SNV) are rodent-borne hantaviruses that cause a highly lethal hemorrhagic fever in humans known as hantavirus pulmonary syndrome (HPS). There are no vaccines or specific drugs to prevent or treat HPS, and the pathogenesis is not understood. Syrian hamsters infected with ANDV, but not SNV, develop a highly lethal disease that closely resembles HPS in humans. Here, we performed a temporal pathogenesis study comparing ANDV and SNV infections in hamsters. SNV was nonpathogenic and viremia was not detected despite the fact that all animals were infected. ANDV was uniformly lethal with a mean time to death of 11 days. The first pathology detected was lymphocyte apoptosis starting on day 4. Animals were viremic and viral antigen was first observed in multiple organs by days 6 and 8, respectively. Levels of infectious virus in the blood increased 4 to 5 logs between days 6 and 8. Pulmonary edema was first detected ultrastructurally on day 6. Ultrastructural analysis of lung tissues revealed the presence of large inclusion bodies and substantial numbers of vacuoles within infected endothelial cells. Paraendothelial gaps were not observed, suggesting that fluid leakage was transcellular and directly attributable to infecting virus. Taken together, these data imply that HPS treatment strategies aimed at preventing virus replication and dissemination will have the greatest probability of success if administered before the viremic phase; however, because vascular leakage is associated with infected endothelial cells, a therapeutic strategy targeting viral replication might be effective even at later times (e.g., after disease onset). PMID:17475651

  3. Effect of heterosubtypic immunity on infection with attenuated influenza A virus vaccines in young children.

    PubMed Central

    Steinhoff, M C; Fries, L F; Karron, R A; Clements, M L; Murphy, B R

    1993-01-01

    Resistance to infection with an influenza A virus conferred by previous infection with an influenza A virus belonging to another subtype is called heterosubtypic immunity. Heterosubtypic immunity is demonstrable in laboratory animals but is believed to be weak in humans. The present study examined whether heterosubtypic immunity from previous influenza virus infection induced resistance to infection with an attenuated influenza A vaccine virus. Two groups of vaccinees consisting of young infants and children who received either influenza A H1N1 or H3N2 attenuated virus were studied. Influenza A H3N2 virus vaccine recipients were classified by their preexisting H1N1 heterosubtypic antibody level induced by prior infection with wild-type virus, and the H1N1 vaccinees were classified by their history of infection with H3N2 vaccine virus. For both groups of vaccinees, the rates of seroconversion and virus shedding and the level of vaccine virus replication were compared in subjects with and without heterosubtypic immunity. In 48 influenza A H3N2 virus and 39 H1N1 virus vaccinees, heterosubtypic immunity had no demonstrable effect on infectivity, immunogenicity, or replication of attenuated vaccine virus. These observations confirm the weak nature of heterosubtypic immunity in humans and suggest that it will not limit the utility of live attenuated influenza A viruses in young infants and children. PMID:8463393

  4. 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

  5. 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 (SHIVE) with several classical HIVE features that include astrocyte infection. We further show an association between severe neuropathological changes, robust resident microglia infection, and evolution to CD4 independence of viruses in the central nervous system (CNS), with expansion to infection of truly CD4-negative cells in vivo. These findings support the use of the R5 SHIVE models to study the contribution of the HIV envelope and viral clades to neurovirulence and residual virus replication in the CNS, providing information that should guide efforts to eradicate HIV from the body. PMID:24829360

  6. 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

  7. Neurological complications of dengue virus infection.

    PubMed

    Carod-Artal, Francisco Javier; Wichmann, Ole; Farrar, Jeremy; Gascn, Joaquim

    2013-09-01

    Dengue is the second most common mosquito-borne disease affecting human beings. In 2009, WHO endorsed new guidelines that, for the first time, consider neurological manifestations in the clinical case classification for severe dengue. Dengue can manifest with a wide range of neurological features, which have been noted--depending on the clinical setting--in 05-21% of patients with dengue admitted to hospital. Furthermore, dengue was identified in 4-47% of admissions with encephalitis-like illness in endemic areas. Neurological complications can be categorised into dengue encephalopathy (eg, caused by hepatic failure or metabolic disorders), encephalitis (caused by direct virus invasion), neuromuscular complications (eg, Guillain-Barr syndrome or transient muscle dysfunctions), and neuro-ophthalmic involvement. However, overlap of these categories is possible. In endemic countries and after travel to these regions, dengue should be considered in patients presenting with fever and acute neurological manifestations. PMID:23948177

  8. West Nile Virus Infection of Birds, Mexico

    PubMed Central

    Guerrero-Snchez, Sergio; Cuevas-Romero, Sandra; Nemeth, Nicole M.; Trujillo-Olivera, Mara Teresa Jess; 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 20062008, 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

  9. Bluetongue virus infection in India: a review.

    PubMed

    Prasad, G; Jain, N C; Gupta, Y

    1992-09-01

    The history and epizootiology of bluetongue (BT) in India are reviewed. BT has become endemic in India. The first outbreak of BT in sheep and goats in the country was recorded in 1964 in Maharashtra State. Since then, several outbreaks of BT have been reported in sheep. Exotic sheep are more susceptible than indigenous and cross-bred sheep. A serological survey has indicated the presence of bluetongue virus (BTV) antibodies in cattle and buffalo in several states in India. However, clinical BT has not been observed in cattle or buffalo to date. Of the 24 known serotypes of BTV, 18 have been reported in India. Although BTV has been isolated from Culicoides midges, the particular species responsible for transmission has not yet been identified. PMID:1335304

  10. Virus-specific antibodies in sera from patients with genital herpes simplex virus infection.

    PubMed Central

    Zweerink, H J; Corey, L

    1982-01-01

    Virus-specific antibodies against a number of herpes simplex virus type 2 antigens were determined by radioimmunoprecipitation assays in sequential serum samples obtained from 12 patients with initial genital herpes simplex virus infection. The progressive appearance of antibodies to virus-specific antigens was observed; antibodies against a 130,000-molecular-weight glycoprotein complex appeared first, followed by antibodies against the major nucleocapsid polypeptide and then antibodies against a number of other viral antigens, including a polypeptide with a molecular weight of 62,000. Patients who developed a wide variety of antibodies to viral polypeptides shortly after resolution of their initial episode seemed to experience more severe initial infections and more recurrences than did those who reacted poorly with these virus-specific antigens. This was most apparent with respect to antibodies to virus-specific polypeptides with molecular weights between 30,000 and 43,000. Antibody specificity did not change during the course of follow-up regardless of whether serum samples were taken shortly before, during, or after recurrent episodes. Glycoprotein-specific antibodies were quantitated with the purified 130,000-molecular-weight glycoprotein material. No significant fluctuations in these antibody titers were observed before or after recurrences of the disease. Images PMID:7118244

  11. Neuroinflammation and Virus Replication in the Spinal Cord of Simian Immunodeficiency Virus-infected Macaques

    PubMed Central

    Mangus, Lisa M.; Dorsey, Jamie L.; Laast, Victoria A.; Hauer, Peter; Queen, Suzanne E.; Adams, Robert J.; McArthur, Justin C.; Mankowski, Joseph L.

    2014-01-01

    Studies of neurologic disease induced by simian immunodeficiency virus (SIV) in Asian macaques have contributed greatly to the current understanding of human immunodeficiency virus (HIV) pathogenesis in the brain and the peripheral nervous system (PNS). Detailed investigations into SIV-induced alterations in the spinal cord, a critical sensorimotor relay point between the brain and the PNS, have yet to be reported. In this study, lumbar spinal cords from SIV-infected pigtailed macaques were examined to quantify SIV replication and associated neuroinflammation. In untreated SIV-infected animals there was a strong correlation between amount of SIV RNA in the spinal cord and expression of the macrophage marker CD68, as well as key pro-inflammatory mediators tumor necrosis factor and CCL2. We also found a significant correlation between SIV-induced alterations in the spinal cord and the degree of distal epidermal nerve fiber loss among untreated animals. Spinal cord changes also were present in SIV-infected antiretroviral-treated animals, including elevated glial fibrillary acidic protein immunostaining and enhanced CCL2 expression despite SIV suppression. A fuller understanding of the complex virus and host factor dynamics in the spinal cord during HIV infection will be critical in the development of new treatments for HIV-associated sensory neuropathies and studies aimed at virus eradication from the central nervous system. PMID:25470348

  12. 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

  13. Prevalence of Hepatitis B virus, Hepatitis C virus and human immunodeficiency virus infections among patients candidate for orthopedic trauma surgeries

    PubMed Central

    Yeganeh, Ali; Hatami, Negin; Mahmoudi, Mani; Boduhi, Bahram; Saidifard, Mahzad; Otoukesh, Babak

    2015-01-01

    Background: Infectious diseases are major public health problems, among which blood-borne ones are the most important infections. Patients who undergo orthopedic surgery are at higher risk of transmitting infectious diseases from and to others, due to repeated blood examinations and injection, drains secretion and receiving blood products. Accordingly, in this study we determined prevalence of Hepatitis B Virus (HBV) Hepatitis C Virus (HCV) and human immunodeficiency Virus (HIV) infections in patients who underwent surgery in a general training hospital. Methods: In this cross-sectional study the prevalence of HBV, HCV, and HIV infections was determined among 320 patients under orthopedic trauma surgeries in a general training hospital in Tehran, Iran from 2009 to 2011. Associations of these rates with age, gender, marital status, residence location, substance abuse history, hospital admission history, previous surgery, blood transfusion, dentistry procedures, and previous medical history were also assessed. Results: A total of 320 patients (290 male, 30 female) were studied. Ten patients (3.2%) had at least one of these three infections. Totally 10 patients (3.2%), 2 subjects (0.6%), and 8 patients (2.5%) had HCV, HIV, and HBV infections, respectively. None of the evaluated variables had significant relationship with HCV, HBV, and HIV infections (p> 0.05). Conclusion: According to the obtained results, routine use of diagnostic tests for infectious disease such as HIV and viral hepatitis is recommended and should be considered before orthopedic operations. PMID:26793665

  14. Host susceptibility to persistent hepatitis B virus infection

    PubMed Central

    He, Ying-Li; Zhao, Ying-Ren; Zhang, Shu-Lin; Lin, Shu-Mei

    2006-01-01

    Genetic epidemiology researches such as twin studies, family-clustering of hepatitis B virus (HBV) infection studies and ethnic difference studies have provided the evidence that host genetic factors play an important role in determining the outcome of HBV infection. The opening questions include which human genes are important in infection and how to find them. Though a number of studies have sought genetic associations between HBV infection/persistence and gene polymorphisms, the candidate gene-based approach is clearly inadequate to fully explain the genetic basis of the disease. With the advent of new genetic markers and automated genotyping, genetic mapping can be conducted extremely rapid. This approach has been successful in some infectious diseases. Linkage analysis can find host genes susceptible to HBV and is of great clinical importance. PMID:16937459

  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. Gene silencing: a therapeutic approach to combat influenza virus infections.

    PubMed

    Khanna, Madhu; Saxena, Latika; Rajput, Roopali; Kumar, Binod; Prasad, Rajendra

    2015-01-01

    Selective gene silencing technologies such as RNA interference (RNAi) and nucleic acid enzymes have shown therapeutic potential for treating viral infections. Influenza virus is one of the major public health concerns around the world and its management is challenging due to a rapid increase in antiviral resistance. Influenza vaccine also has its limitations due to the emergence of new strains that may escape the immunity developed by the previous year's vaccine. Antiviral drugs are the primary mode of prevention and control against a pandemic and there is an urgency to develop novel antiviral strategies against influenza virus. In this review, we discuss the potential utility of several gene silencing mechanisms and their prophylactic and therapeutic potential against the influenza virus. PMID:25598342

  17. 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

  18. NTCP opens the door for hepatitis B virus infection.

    PubMed

    Yan, Huan; Liu, Yang; Sui, Jianhua; Li, Wenhui

    2015-09-01

    A liver bile acids transporter, sodium taurocholate cotransporting polypeptide (NTCP, encoded by SLC10A1) was recently identified as a functional receptor for hepatitis B virus (HBV) and its satellite hepatitis D virus (HDV). NTCP-complemented human hepatoma HepG2 cells (HepG2-NTCP) were shown to support infection of HBV and HDV in vitro, providing a much-needed and convenient cell culture system for the viruses. Identification of NTCP as a functional receptor for HBV has significantly advanced our understanding of the viral life cycle and opened new opportunities for developing anti-HBV interventions. This article forms part of a symposium in Antiviral Research on "An unfinished story: from the discovery of the Australia antigen to the development of new curative therapies for hepatitis B". PMID:26071008

  19. Viruses infecting marine picoplancton encode functional potassium ion channels.

    PubMed

    Siotto, Fenja; Martin, Corinna; Rauh, Oliver; Van Etten, James L; Schroeder, Indra; Moroni, Anna; Thiel, Gerhard

    2014-10-01

    Phycodnaviruses are dsDNA viruses, which infect algae. Their large genomes encode many gene products, like small K(+) channels, with homologs in prokaryotes and eukaryotes. Screening for K(+) channels revealed their abundance in viruses from fresh-water habitats. Recent sequencing of viruses from marine algae or from salt water in Antarctica revealed sequences with the predicted characteristics of K(+) channels but with some unexpected features. Two genes encode either 78 or 79 amino acid proteins, which are the smallest known K(+) channels. Also of interest is an unusual sequence in the canonical ?-helixes in K(+) channels. Structural prediction algorithms indicate that the new channels have the conserved ?-helix folds but the algorithms failed to identify the expected transmembrane domains flanking the K(+) channel pores. In spite of these unexpected properties electophysiological studies confirmed that the new proteins are functional K(+) channels. PMID:25441713

  20. Coxsackie B virus infection in coronary care unit patients.

    PubMed Central

    O'Neill, D; McArthur, J D; Kennedy, J A; Clements, G

    1983-01-01

    It has been suggested that Coxsackie B virus infections may play a part in causing or triggering myocardial infarction. This study was designed to compare the incidence of such infections in Coronary Care Unit patients and normal controls. The choice of a suitable criterion for diagnosis of Coxsackie infection is discussed fully. Two hundred and fifty admissions to a Coronary Care Unit and 100 control subjects had a serum sample tested by microneutralisation for Coxsackie B antibodies. The incidence of infection among 130 patients diagnosed as acute myocardial infarction was 5% compared with 4% in the control group. In a subgroup classified as non-transmural myocardial infarction, the incidence of infection was 14%. The sex ratio of this group differed from the myocardial infarction group as a whole suggesting that the non-transmural group may not have been homogeneous. Normal coronary arteriograms were subsequently found in three patients who were diagnosed as non-transmural myocardial infarction but who had serological evidence of recent Coxsackie infection. This study does not demonstrate an association between Coxsackie infection and myocardial infarction as a whole and does not support the view that Coxsackie infection causes or provokes myocardial infarction. It does, however, suggest that myocarditis may simulate non-transmural infarction. PMID:6304150

  1. Respiratory syncytial virus infection increases chlorine-induced airway hyperresponsiveness.

    PubMed

    Song, Weifeng; Yu, Zhihong; Doran, Stephen F; Ambalavanan, Namasivayam; Steele, Chad; Garantziotis, Stavros; Matalon, Sadis

    2015-08-01

    Exposure to chlorine (Cl2) damages airway and alveolar epithelia resulting in acute lung injury and reactive airway hyperresponsiveness (AHR) to methacholine. However, little is known about the effect of preexisting respiratory disease on Cl2-induced lung injury. By using a murine respiratory syncytial virus (RSV) infection model, we found that preexisting RSV infection increases Cl2 (187 ppm for 30 min)-induced lung inflammation and airway AHR at 24 h after exposure (5 days after infection). RSV infection and Cl2 exposure synergistically induced oxygen desaturation and neutrophil infiltration and increased MCP-1, MIP-1β, IL-10, IFN-γ, and RANTES concentrations in the bronchoalveolar lavage fluid (BALF). In contrast, levels of type 2 cytokines (i.e., IL-4, IL-5, IL-9, and IL-13) were not significantly affected by either RSV infection or Cl2 exposure. Cl2 exposure, but not RSV infection, induced AHR to methacholine challenge as measured by flexiVent. Moreover, preexisting RSV infection amplified BALF levels of hyaluronan (HA) and AHR. The Cl2-induced AHR was mitigated by treatment with inter-α-trypsin inhibitor antibody, which inhibits HA signaling, suggesting a mechanism of HA-mediated AHR from exacerbated oxidative injury. Our results show for the first time that preexisting RSV infection predisposes the lung to Cl2-induced injury. These data emphasize the necessity for further research on the effects of Cl2 in vulnerable populations and the development of appropriate treatments. PMID:26071553

  2. Modeling Influenza Virus Infection: A Roadmap for Influenza Research.

    PubMed

    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

    2015-10-01

    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

  3. Ovine fetal immune response to Cache Valley virus infection.

    PubMed

    Rodrigues Hoffmann, Aline; Dorniak, Piotr; Filant, Justyna; Dunlap, Kathrin A; Bazer, Fuller W; de la Concha-Bermejillo, Andres; Welsh, Christabel Jane; Varner, Patricia; Edwards, John Francis

    2013-05-01

    Cache Valley virus (CVV)-induced malformations have been previously reproduced in ovine fetuses. To evaluate the development of the antiviral response by the early, infected fetus, before the development of immunocompetency, ovine fetuses at 35 days of gestation were inoculated in utero with CVV and euthanized at 7, 10, 14, 21, and 28 days postinfection. The antiviral immune response in immature fetuses infected with CVV was evaluated. Gene expression associated with an innate, immune response was quantified by real-time quantitative PCR. The upregulated genes in infected fetuses included ISG15, Mx1, Mx2, IL-1, IL-6, TNF-?, TLR-7, and TLR-8. The amount of Mx1 protein, an interferon-stimulated GTPase capable of restricting growth of bunyaviruses, was elevated in the allantoic and amniotic fluid in infected fetuses. ISG15 protein expression was significantly increased in target tissues of infected animals. B lymphocytes and immunoglobulin-positive cells were detected in lymphoid tissues and in the meninges of infected animals. These results demonstrated that the infected ovine fetus is able to initiate an innate and adaptive immune response much earlier than previously known, which presumably contributes to viral clearance in infected animals. PMID:23468505

  4. Ovine Fetal Immune Response to Cache Valley Virus Infection

    PubMed Central

    Dorniak, Piotr; Filant, Justyna; Dunlap, Kathrin A.; Bazer, Fuller W.; de la Concha-Bermejillo, Andres; Welsh, Christabel Jane; Varner, Patricia

    2013-01-01

    Cache Valley virus (CVV)-induced malformations have been previously reproduced in ovine fetuses. To evaluate the development of the antiviral response by the early, infected fetus, before the development of immunocompetency, ovine fetuses at 35 days of gestation were inoculated in utero with CVV and euthanized at 7, 10, 14, 21, and 28 days postinfection. The antiviral immune response in immature fetuses infected with CVV was evaluated. Gene expression associated with an innate, immune response was quantified by real-time quantitative PCR. The upregulated genes in infected fetuses included ISG15, Mx1, Mx2, IL-1, IL-6, TNF-?, TLR-7, and TLR-8. The amount of Mx1 protein, an interferon-stimulated GTPase capable of restricting growth of bunyaviruses, was elevated in the allantoic and amniotic fluid in infected fetuses. ISG15 protein expression was significantly increased in target tissues of infected animals. B lymphocytes and immunoglobulin-positive cells were detected in lymphoid tissues and in the meninges of infected animals. These results demonstrated that the infected ovine fetus is able to initiate an innate and adaptive immune response much earlier than previously known, which presumably contributes to viral clearance in infected animals. PMID:23468505

  5. Preventing toxoplasmic encephalitis in persons infected with human immunodeficiency virus.

    PubMed

    Richards, F O; Kovacs, J A; Luft, B J

    1995-08-01

    Toxoplasmic encephalitis (TE) is the second most common AIDS-related opportunistic infection of the CNS. It occurs in 10%-50% of patients with AIDS who are seropositive for antibodies to Toxoplasma gondii and have CD4+ T lymphocyte counts of < 100/mm3. Primary toxoplasmic infection usually is acquired by ingestion of T. gondii oocysts from soil contaminated by cat feces or by ingestion of tissue cysts present in undercooked red meats. In patients with AIDS, TE probably results from the reactivation of Toxoplasma tissue cysts that remained latent after the primary infection. Detection of IgG antibodies to Toxoplasma indicates prior infection and the possible presence of tissue cysts and, thus, risk for developing TE. A regimen of trimethoprim-sulfamethoxazole or dapsone plus pyrimethamine with leucovorin is recommended for persons infected with the human immunodeficiency virus (HIV) and who are seropositive for IgG to Toxoplasma after their CD4+ T lymphocyte counts fall to < 100/mm3. HIV-infected persons who are seronegative for IgG to Toxoplasma should be counseled to protect themselves from primary toxoplasmic infection by eating only well-cooked meats and washing their hands after outdoor activities involving soil contact; if they have a cat, they should feed it only commercial or well-cooked foods, keep it indoors, and make sure that the litter box is changed daily. HIV-infected persons who are Toxoplasma seropositive may also be advised about these preventive behavioral practices. PMID:8547512

  6. 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

  7. 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

  8. Host detection and the stealthy phenotype in influenza virus infection.

    PubMed

    Dash, Pradyot; Thomas, Paul G

    2015-01-01

    The innate host response to influenza virus infection plays a critical role in determining the subsequent course of infection and the clinical outcome of disease. The host has a diverse array of detection and effector mechanisms that are able to recognize and initiate effective antiviral responses. In opposition, the virus utilizes a number of distinct mechanisms to evade host detection and effector activity in order to remain "stealthy" throughout its replication cycle. In this review, we describe these host and viral mechanisms, including the major pattern recognition receptor families (the TLRs, NLRs, and RLRs) in the host and the specific viral proteins such as NS1 that are key players in this interaction. Additionally, we explore nonreductive mechanisms of viral immune evasion and propose areas important for future inquiry. PMID:25038940

  9. Detection of Zika Virus Infection in Thailand, 2012-2014.

    PubMed

    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

    2015-08-01

    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

  10. Acute EpsteinBarr virus infection-associated collapsing glomerulopathy

    PubMed Central

    Joshi, Amit; Arora, Amit; Cimbaluk, David; Dunea, George; Hart, Peter

    2012-01-01

    A 21-year-old woman presenting with acute EpsteinBarr virus (EBV) infection (infectious mononucleosis) was noted to have renal involvement. She had proteinuria, leukocyturia and microscopic hematuria, and 10 days after admission became nephrotic (23 g of protein per g of creatinine). Renal biopsy revealed glomerular tuft collapse, visceral epithelial cell proliferation and vacuolization consistent with collapsing glomerulopathy. She had only transient deterioration in renal function, attributed to contrast nephropathy, but after recovery remained proteinuric. Renal disease is well described in EBV infection, but collapsing glomerulopathy has not been reported previously. PMID:25874088

  11. 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

  12. Epidemiology and prevention of hepatitis B virus infection.

    PubMed

    Kwon, So Young; Lee, Chang Hong

    2011-06-01

    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. Predictors for Early Identification of Hepatitis C Virus Infection.

    PubMed

    Tsai, Mei-Hua; Lin, Kuei-Hsiang; Lin, Kuan-Tsou; Hung, Chi-Ming; Cheng, Hung-Shiang; Tyan, Yu-Chang; Huang, Hui-Wen; Sanno-Duanda, Bintou; Yang, Ming-Hui; Yuan, Shyng-Shiou; Chu, Pei-Yu

    2015-01-01

    Hepatitis C virus (HCV) infection can cause permanent liver damage and hepatocellular carcinoma, and deaths related to HCV deaths have recently increased. Chronic HCV infection is often undiagnosed such that the virus remains infective and transmissible. Identifying HCV infection early is essential for limiting its spread, but distinguishing individuals who require further HCV tests is very challenging. Besides identifying high-risk populations, an optimal subset of indices for routine examination is needed to identify HCV screening candidates. Therefore, this study analyzed data from 312 randomly chosen blood donors, including 144 anti-HCV-positive donors and 168 anti-HCV-negative donors. The HCV viral load in each sample was measured by real-time polymerase chain reaction method. Receiver operating characteristic curves were used to find the optimal cell blood counts and thrombopoietin measurements for screening purposes. Correlations with values for key indices and viral load were also determined. Strong predictors of HCV infection were found by using receiver operating characteristics curves to analyze the optimal subsets among red blood cells, monocytes, platelet counts, platelet large cell ratios, and mean corpuscular hemoglobin concentrations. Sensitivity, specificity, and area under the receiver operator characteristic curve (P < 0.0001) were 75.6%, 78.5%, and 0.859, respectively. PMID:26413522

  14. Predictors for Early Identification of Hepatitis C Virus Infection

    PubMed Central

    Tsai, Mei-Hua; Lin, Kuei-Hsiang; Lin, Kuan-Tsou; Hung, Chi-Ming; Cheng, Hung-Shiang; Tyan, Yu-Chang; Huang, Hui-Wen; Sanno-Duanda, Bintou; Yang, Ming-Hui; Yuan, Shyng-Shiou; Chu, Pei-Yu

    2015-01-01

    Hepatitis C virus (HCV) infection can cause permanent liver damage and hepatocellular carcinoma, and deaths related to HCV deaths have recently increased. Chronic HCV infection is often undiagnosed such that the virus remains infective and transmissible. Identifying HCV infection early is essential for limiting its spread, but distinguishing individuals who require further HCV tests is very challenging. Besides identifying high-risk populations, an optimal subset of indices for routine examination is needed to identify HCV screening candidates. Therefore, this study analyzed data from 312 randomly chosen blood donors, including 144 anti-HCV-positive donors and 168 anti-HCV-negative donors. The HCV viral load in each sample was measured by real-time polymerase chain reaction method. Receiver operating characteristic curves were used to find the optimal cell blood counts and thrombopoietin measurements for screening purposes. Correlations with values for key indices and viral load were also determined. Strong predictors of HCV infection were found by using receiver operating characteristics curves to analyze the optimal subsets among red blood cells, monocytes, platelet counts, platelet large cell ratios, and mean corpuscular hemoglobin concentrations. Sensitivity, specificity, and area under the receiver operator characteristic curve (P < 0.0001) were 75.6%, 78.5%, and 0.859, respectively. PMID:26413522

  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. M-protein-positive chronic active Epstein-Barr virus infection: features mimicking HIV-1 infection.

    PubMed

    Imashuku, Shinsaku; Azuma, Naoto; Kanegane, Hirokazu; Kasahara, Yoshihito

    2009-09-01

    Chronic active Epstein-Barr virus infection (CAEBV) is a unique and fatal lymphoproliferative disease (LPD), which often shows high serum IgG and/or IgE. The significance of such immunoglobulin abnormalities in CAEBV has not been fully evaluated and discussed. In addition, such clinical features mimic HIV-1 infection. We report here a case of CAEBV with M-protein detected which may shed a new light on the pathogenesis of this disease. PMID:19588219

  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 Mareks 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. [Epidemiology of hepatitis E virus infection in Spain].

    PubMed

    Echevarra, Jos Manuel; Fogeda, Marta; Avelln, 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

  19. 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

  20. A Bacteriophage-Related Chimeric Marine Virus Infecting Abalone

    PubMed Central

    Zhuang, Jun; Cai, Guiqin; Lin, Qiying; Wu, Zujian; Xie, Lianhui

    2010-01-01

    Marine viruses shape microbial communities with the most genetic diversity in the sea by multiple genetic exchanges and infect multiple marine organisms. Here we provide proof from experimental infection that abalone shriveling syndrome-associated virus (AbSV) can cause abalone shriveling syndrome. This malady produces histological necrosis and abnormally modified macromolecules (hemocyanin and ferritin). The AbSV genome is a 34.952-kilobase circular double-stranded DNA, containing putative genes with similarity to bacteriophages, eukaryotic viruses, bacteria and endosymbionts. Of the 28 predicted open reading frames (ORFs), eight ORF-encoded proteins have identifiable functional homologues. The 4 ORF products correspond to a predicted terminase large subunit and an endonuclease in bacteriophage, and both an integrase and an exonuclease from bacteria. The other four proteins are homologous to an endosymbiont-derived helicase, primase, single-stranded binding (SSB) protein, and thymidylate kinase, individually. Additionally, AbSV exhibits a common gene arrangement similar to the majority of bacteriophages. Unique to AbSV, the viral genome also contains genes associated with bacterial outer membrane proteins and may lack the structural protein-encoding ORFs. Genomic characterization of AbSV indicates that it may represent a transitional form of microbial evolution from viruses to bacteria. PMID:21079776