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Sample records for giant viruses infecting

  1. 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

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

    PubMed Central

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

    2010-01-01

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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

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

    PubMed

    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. PMID:27055288

  10. 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.

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

    PubMed

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

    2012-10-30

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

  12. 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

  13. 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

  14. 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

  15. Giant Viruses of Amoebas: An Update.

    PubMed

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

    2016-01-01

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

  16. Giant Viruses of Amoebas: An Update

    PubMed Central

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

    2016-01-01

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

  17. 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

  18. Zika Virus Infection

    MedlinePlus

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

  19. 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

  20. 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

  1. Akabane virus infection.

    PubMed

    Kirkland, P D

    2015-08-01

    Akabane virus is a Culicoides-borne orthobunyavirus that is teratogenic to the fetus of cattle and small ruminant species. Depending upon the stage of gestation atwhich infection occurs, and the length of gestation of the mammalian host, a range of congenital defects may be observed. The developing central nervous system is usually the most severely affected, with hydranencephaly and arthrogryposis most frequently observed. Less commonly, some strains of Akabane virus can cause encephalitis in the neonate or, rarely, adult cattle. Akabane viruses are known to be widespread in temperate and tropical regions of Australia, Southeast Asia, the Middle East and some African countries. Disease is infrequently observed in regions where this virus is endemic and the presence of the virus remains unrecognised in the absence of serological surveillance. In some Asian countries, vaccines are used to minimise the occurrence of disease. PMID:26601444

  2. Schmallenberg virus infection.

    PubMed

    Wernike, K; Elbers, A; Beer, M

    2015-08-01

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

  3. 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

  4. [Zika virus infection during pregnancy].

    PubMed

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

    2016-05-01

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

  5. 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

  6. 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

  7. 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

  8. Avian Influenza A Virus Infections in Humans

    MedlinePlus

    ... Past Newsletters Avian Influenza A Virus Infections in Humans Language: English Español Recommend on Facebook Tweet ... A Viruses Avian Influenza A Virus Infections in Humans Although avian influenza A viruses usually do not ...

  9. 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

  10. 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

  11. 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

  12. Human Immunodeficiency Virus (HIV) Primary Infection

    MedlinePlus

    ... rash and rashes clinical tools newsletter | contact Share | Human Immunodeficiency Virus (HIV) Primary Infection Information for adults ... 1–6 weeks following exposure to HIV (the human immunodeficiency virus). Chronic infection with this virus can ...

  13. Soy isoflavones and virus infections

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Isoflavones and their related flavonoid compounds exert antiviral properties in vitro and in vivo against a wide range of viruses. Genistein is, by far, the most studied soy isoflavone in this regard, and it has been shown to inhibit the infectivity of enveloped or nonenveloped viruses, as well as s...

  14. 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 ...

  15. 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

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

    PubMed Central

    2014-01-01

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

  17. Zika Virus Infection

    MedlinePlus

    ... provide technical support for pilot studies of new mosquito control technologies Llaman a incorporar al zika en la ... of Disease Still Unclear PAHO answers questions about mosquito control for Zika Virus Sesame Street Muppets Join PAHO ...

  18. 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

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

    PubMed

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

    2015-01-01

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

  20. 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

  1. 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

  2. Neonatal Herpes Simplex Virus Infection.

    PubMed

    James, Scott H; Kimberlin, David W

    2015-09-01

    Herpes simplex virus (HSV) 1 and HSV-2 infections are highly prevalent worldwide and are characterized by establishing lifelong infection with periods of latency interspersed with periodic episodes of reactivation. Acquisition of HSV by an infant during the peripartum or postpartum period results in neonatal HSV disease, a rare but significant infection that can be associated with severe morbidity and mortality, especially if there is dissemination or central nervous system involvement. Diagnostic and therapeutic advances have led to improvements in mortality and, to a lesser extent, neurodevelopmental outcomes, but room exists for further improvement. PMID:26154662

  3. Dengue Virus Infection in Africa

    PubMed Central

    Kuritsky, Joel N.; Letson, G. William; Margolis, Harold S.

    2011-01-01

    Reported incidence of dengue has increased worldwide in recent decades, but little is known about its incidence in Africa. During 1960–2010, a total of 22 countries in Africa reported sporadic cases or outbreaks of dengue; 12 other countries in Africa reported dengue only in travelers. The presence of disease and high prevalence of antibody to dengue virus in limited serologic surveys suggest endemic dengue virus infection in all or many parts of Africa. Dengue is likely underrecognized and underreported in Africa because of low awareness by health care providers, other prevalent febrile illnesses, and lack of diagnostic testing and systematic surveillance. Other hypotheses to explain low reported numbers of cases include cross-protection from other endemic flavivirus infections, genetic host factors protecting against infection or disease, and low vector competence and transmission efficiency. Population-based studies of febrile illness are needed to determine the epidemiology and true incidence of dengue in Africa. PMID:21801609

  4. 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

  5. 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

  6. Probiotics in respiratory virus infections.

    PubMed

    Lehtoranta, L; Pitkäranta, A; Korpela, R

    2014-08-01

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

  7. 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

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

    PubMed

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

    2016-06-15

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

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

    PubMed Central

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

    2016-01-01

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

  10. 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

  11. 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

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

    PubMed

    Claverie, Jean-Michel

    2013-11-01

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

  13. 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

  14. 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

  15. 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...

  16. Models of dengue virus infection

    PubMed Central

    Bente, Dennis A.; Rico-Hesse, Rebeca

    2007-01-01

    The need for models of dengue disease has reached a pinnacle as the transmission of this mosquito-borne virus has increased dramatically. Little is known about the mechanisms that lead to dengue fever and its more severe form, dengue hemorrhagic fever; this is owing to the fact that only humans show signs of disease. In the past 5 years, research has better identified the initial target cells of infection, and this has led to the development of models of infection in primary human cell cultures. Mouse–human chimeras, containing these target cells, have also led to progress in developing animal models. These advances should soon end the stalemate in testing antivirals and vaccine preparations that had necessarily been done in incomplete or irrelevant models. PMID:18087566

  17. 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

  18. 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

  19. 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

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

    PubMed

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

    2014-08-29

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

  1. Immunopathogenesis of Hepatitis C Virus Infection.

    PubMed

    Kaplan, David E

    2015-12-01

    Despite advances in therapy, hepatitis C virus infection remains a major global health issue with 3 to 4 million incident cases and 170 million prevalent chronic infections. Complex, partially understood, host-virus interactions determine whether an acute infection with hepatitis C resolves, as occurs in approximately 30% of cases, or generates a persistent hepatic infection, as occurs in the remainder. Once chronic infection is established, the velocity of hepatocyte injury and resultant fibrosis is significantly modulated by immunologic as well as environmental factors. Immunomodulation has been the backbone of antiviral therapy despite poor understanding of its mechanism of action. PMID:26600217

  2. 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

  3. 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

  4. 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

  5. The Epidemiology of Human Immunodeficiency Virus Infection.

    ERIC Educational Resources Information Center

    Glasner, Peter D.; Kaslow, Richard A.

    1990-01-01

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

  6. 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

  7. Influenza Virus Infection of Marine Mammals.

    PubMed

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

    2016-03-01

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

  8. 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

  9. 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

  10. 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.

  11. [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

  12. 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

  13. METHODS USED TO STUDY RESPIRATORY VIRUS INFECTION

    PubMed Central

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

    2009-01-01

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

  14. 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

  15. 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

  16. 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

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

    PubMed Central

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

    2015-01-01

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

  18. Physiological significance of apoptosis in animal virus infection.

    PubMed

    Koyama, A H; Fukumori, T; Fujita, M; Irie, H; Adachi, A

    2000-07-01

    In contrast to insect viruses, animal viruses can produce considerable amounts of progeny virus in cells undergoing apoptosis. Nevertheless, viruses in general have acquired the ability to escape apoptosis of infected cells. These facts indicate that the role of apoptosis in virus infection is different in insect virus and animal virus, although both viruses need to avoid apoptosis of the infected cells for a viral life cycle in nature. In animal virus infection, the primary role of apoptosis is considered not to be a premature lysis of the infected cells (and the following abortion of virus multiplication) but to allow the dying cells to be phagocytosed by macrophages. This phagocytosis is able to prevent dysregulated inflammatory reactions at the site of virus infection and to initiate a specific immune response against the infected virus. PMID:10967291

  19. 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

  20. Molecular Biology of Hepatitis B Virus Infection

    PubMed Central

    Seeger, Christoph; Mason, William S.

    2015-01-01

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

  1. 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 ...

  2. 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

  3. Experimental Schmallenberg virus infection of pigs.

    PubMed

    Poskin, Antoine; Van Campe, Willem; Mostin, Laurent; Cay, Brigitte; De Regge, Nick

    2014-06-01

    Schmallenberg virus (SBV) is a newly emerged virus responsible for an acute non-specific syndrome in adult cattle including high fever, decrease in milk production and severe diarrhea. It also causes reproductive problems in cattle, sheep and goat including abortions, stillbirths and malformations. The role of pigs in the epidemiology of SBV has not yet been evaluated while this could be interesting seen their suggested role in the epidemiology of the closely related Akabane virus. To address this issue, four 12 week old seronegative piglets were subcutaneously infected with 1 ml of SBV infectious serum (FLI) and kept into contact with four non-infected piglets to examine direct virus transmission. Throughout the experiment blood, swabs and feces samples were collected and upon euthanasia at 28 dpi different organs (cerebrum, cerebellum, brain stem, lung, liver, iliac lymph nodes, kidney and spleen) were sampled. No clinical impact was observed and all collected samples tested negative for SBV in rRT-PCR. Despite the absence of viremia and virus transmission, low and short lasting amounts of neutralizing antibodies were found in 2 out of 4 infected piglets. The limited impact of SBV infection in pigs was further supported by the absence of neutralizing anti-SBV antibodies in field collected sera from indoor housed domestic pigs (n=106). In conclusion, SBV infection of pigs can induce seroconversion but is ineffective in terms of virus replication and transmission indicating that pigs have no obvious role in the SBV epidemiology. PMID:24679959

  4. 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

  5. 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

  6. 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...

  7. 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

  8. 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

  9. 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

  10. 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

  11. [Human immunodeficiency virus infection - treatment beyond medication].

    PubMed

    Teixeira, Carla; Rodrigues, Paula; Cardoso, Cármen; Morais, Angélica; Sequeira, Fátima; Diz, Alcinda; Santos, M Carmo; Marques, Laura

    2010-01-01

    Human Immunodeficiency Virus (HIV) infection is presently considered a chronic disorder. Infected people need a thorough medical surveillance and chronic therapy, which affects families and other caregivers. Infected children are also affected by their parents' infection and by the stigma that is still associated with this particular illness. Regular meetings were organized for HIV infected children, their families and the health team with recreational and formative purposes. These meetings were evaluated in a strongly positive manner by all the intervenients. The goal to maintain these activities is proposed as a way of improving the follow-up and the prognosis of these children. PMID:21144321

  12. 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

  13. 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

  14. Molecular diagnosis of respiratory virus infections.

    PubMed

    Mahony, James B; Petrich, Astrid; Smieja, Marek

    2011-01-01

    The appearance of eight new respiratory viruses, including the SARS coronavirus in 2003 and swine-origin influenza A/H1N1 in 2009, in the human population in the past nine years has tested the ability of virology laboratories to develop diagnostic tests to identify these viruses. Nucleic acid based amplification tests (NATs) for respiratory viruses were first introduced two decades ago and today are utilized for the detection of both conventional and emerging viruses. These tests are more sensitive than other diagnostic approaches, including virus isolation in cell culture, shell vial culture (SVC), antigen detection by direct fluorescent antibody (DFA) staining, and rapid enzyme immunoassay (EIA), and now form the backbone of clinical virology laboratory testing around the world. NATs not only provide fast, accurate and sensitive detection of respiratory viruses in clinical specimens but also have increased our understanding of the epidemiology of both new emerging viruses such as the pandemic H1N1 influenza virus of 2009, and conventional viruses such as the common cold viruses, including rhinovirus and coronavirus. Multiplex polymerase chain reaction (PCR) assays introduced in the last five years detect up to 19 different viruses in a single test. Several multiplex PCR tests are now commercially available and tests are working their way into clinical laboratories. The final chapter in the evolution of respiratory virus diagnostics has been the addition of allelic discrimination and detection of single nucleotide polymorphisms associated with antiviral resistance. These assays are now being multiplexed with primary detection and subtyping assays, especially in the case of influenza virus. These resistance assays, together with viral load assays, will enable clinical laboratories to provide physicians with new and important information for optimal treatment of respiratory virus infections. PMID:22185616

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

    PubMed Central

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

    2005-01-01

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

  16. [BK virus infections in kidney transplantation].

    PubMed

    Lanot, Antoine; Bouvier, Nicolas; Chatelet, Valérie; Dina, Julia; Béchade, Clémence; Ficheux, Maxence; Henri, Patrick; Lobbedez, Thierry; Hurault de Ligny, Bruno

    2016-04-01

    BK virus is near ubiquitous, with a seroprevalence of around 80% in the general population. Subsequent to an asymptomatic primary infection, BK virus then remains dormant in healthy subjects. Reactivation occurs in immunocompromised people. BKv is pathogenic mainly among patients who have received a kidney transplant, in whom the virus can cause specific tubulo-interstitial nephritis and even result in graft failure among approximately 20 to 30% of nephritic cases. Since the mid 90s, incidence has increased with the use of new powerful immunosuppressor treatments. The cornerstone of BK virus infection or BK virus-associated nephropathy treatment is a decrease of the immunosuppressive regimen, which must then be offset with the risk of rejection. The use of several adjuvant therapies has been submitted (fluoroquinolones, leflunomide, intravenous immunoglobulins, cidofovir), with no sufficient proof enabling the recommendation of first-line prescription. The high frequency of this infection and its potential harmfulness argue for the use of prevention strategies, at least among patients presenting risk factors. Retransplantation is safe after a first kidney allograft loss caused by BK-virus nephropathy, on condition that a screening for viremia is frequently conducted. PMID:26827190

  17. Pathway of Infection of Mosquito Iridescent Virus

    PubMed Central

    Stoltz, D. B.; Summers, M. D.

    1971-01-01

    Mosquito iridescent virus (MIV) is ingested in large amounts by first- and second-instar Aedes taeniorhynchus larvae without causing a high rate of infection. Electron microscope studies have been undertaken to determine the fate of ingested virus. Preliminary observations suggest that most, if not all, ingested particles are degraded shortly after entering the midgut. MIV and other virus particles employed in this study were apparently unable to penetrate the peritrophic membrane; consequently, none was observed inside, or in contact with, midgut epithelial cells. Images PMID:4152171

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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)

  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. Lethal Dengue Virus Infection: A Forensic Overview.

    PubMed

    Byard, Roger W

    2016-06-01

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

  7. 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

  8. 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

  9. Uterine adenocarcinoma with feline leukemia virus infection

    PubMed Central

    Cho, Sung-Jin; Lee, Hyun-A; Hong, Sunhwa

    2011-01-01

    Feline endometrial adenocarcinomas are uncommon malignant neoplasms that have been poorly characterized to date. In this study, we describe a uterine adenocarcinoma in a Persian cat with feline leukemia virus infection. At the time of presentation, the cat, a female Persian chinchilla, was 2 years old. The cat underwent surgical ovariohystectomy. A cross-section of the uterine wall revealed a thickened uterine horn. The cat tested positive for feline leukemia virus as detected by polymerase chain reaction. Histopathological examination revealed uterine adenocarcinoma that had metastasized to the omentum, resulting in thickening and the formation of inflammatory lesions. Based on the histopathological findings, this case was diagnosed as a uterine adenocarcinoma with abdominal metastasis. To the best of our knowledge, this is the first report of a uterine adenocarcinoma with feline leukemia virus infection. PMID:22232645

  10. 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...

  11. 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

  12. Oral Manifestations of Human Immunodeficiency Virus Infection

    PubMed Central

    Epstein, Joel B.; Mathias, Richard G.

    1988-01-01

    The AIDS epidemic continues. All health-care workers, including physicians and dental personnel, may be instrumental in recognizing risk factors associated with Acquired Immunodeficiency Syndrome (AIDS) and Human Immunodeficiency Virus (HIV) infection. Oral signs and symptoms of HIV infection may be the first presentation of the disease or may develop during the course of the disease and require management. Knowledge of the signs, symptoms and associated infections and tumours is needed to assist in recognition, diagnosis, and treatment. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6Figure 7Figure 8Figure 9Figure 10Figure 11Figure 12Figure 13 PMID:21253078

  13. Pathological consequences of systemic measles virus infection.

    PubMed

    Ludlow, Martin; McQuaid, Stephen; Milner, Dan; de Swart, Rik L; Duprex, W Paul

    2015-01-01

    The identification of poliovirus receptor-like 4 (PVRL4) as the second natural receptor for measles virus (MV) has closed a major gap in our understanding of measles pathogenesis, and explains how this predominantly lymphotropic virus breaks through epithelial barriers to transmit to a susceptible host. Advances in the development of wild-type, recombinant MVs which express fluorescent proteins making infected cells readily detectable in living tissues and animals, has also increased our understanding of this important and highly transmissible human disease. Thus, it is timely to review how these advances have provided new insights into MV infection of immune, epithelial and neural cells. This demands access to primate samples that help us understand the early and acute stages of the disease, which are challenging to dissect due to the mild/self-limiting nature of the infection. It also requires well-characterized and rather rare human tissue samples from patients who succumb to neurological sequelae to help study the consequences of the long-term persistence of this RNA virus in vivo. Collectively, these studies have provided unique insights into how the use of two cellular receptors, CD150 and PVRL4, governs the in vivo tissue-specific temporal patterns of virus spread and resulting pathological lesions. Analysis of tissue samples has also demonstrated the importance of differing mechanisms of virus cell-to-cell spread within lymphoid, epithelial and neural tissues in the dissemination of MV during acute and long-term persistent infections. Given the incentive to eradicate MV globally, and the inevitable question as to whether or not vaccination should cease in light of the existence of closely related morbilliviruses, a thorough understanding of measles pathological lesions is essential. PMID:25294240

  14. 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

  15. 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. PMID:26205627

  16. 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.

  17. 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

  18. 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

  19. [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

  20. 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 10 days 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

  1. 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

  2. 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...

  3. 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

  4. 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

  5. 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

  6. 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.

  7. 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

  8. 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...

  9. 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

  10. 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.

  11. Vaccinia Virus Infection Requires Maturation of Macropinosomes.

    PubMed

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

    2015-08-01

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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. Management of hepatitis B virus infection.

    PubMed

    Lee, Haeok; Park, Wanju; Yang, Jin Hyang; You, Kwang Soo

    2010-01-01

    An estimated 2 million people are living with chronic hepatitis B virus (CHBV) in the United States and are at risk for long-term consequences such as cirrhosis, liver decompensation, and hepatocellular carcinoma. Less than 10 years ago, there was no treatment of CHBV infection, but now, new drugs have recently been approved and there is considerable new knowledge about the treatment of CHBV infection. Recently, consensus guidelines for the management of hepatitis B virus infection have been released by the National Institutes of Health and the American Medical Association, addressing the selection of patients and drugs for treatments. Determining what constitutes best practices to manage patients with CHBV is challenging and requires nurses and nurse practitioners to acquire and maintain up-to-date knowledge to understand recently approved drugs and disease management. Nurses and nurse practitioners should know how to identify patients who need treatment and how to educate, counsel, and monitor treatment adherence and side effects; these skills are crucially important. The goal of this article is to provide nurses with the most current consensus guidelines for the management of CHBV infection and their application in nursing practice to optimize treatment to enhance patient outcomes. PMID:20389225

  18. 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

  19. 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...

  20. Patterns of Puumala virus infection in Finland.

    PubMed

    Rose, A M C; Vapalahti, O; Lyytikäinen, O; Nuorti, P

    2003-01-01

    Puumala hantavirus infection is prevalent throughout most of Europe, and in endemic areas it may be the most common cause of acute renal failure. To evaluate trends in incidence of Puumala virus infections in Finland, we analysed national surveillance data in 12-month periods from March 1995 to February 2002. During this time, 8184 laboratory-confirmed cases were notified to the National Infectious Disease Register. Three epidemic periods were identified, for which the number of cases was more than 1400 (there were approximately 600-900 cases per non-epidemic period). The incidence of Puumala hantavirus infection varied by geographic region during the study period, and the overall number of cases may be increasing. PMID:12631978

  1. [Chikungunya virus infections in children].

    PubMed

    Haas, H; Robin, S; Ramful, D; Houdon, L; Minodier, P; Gérardin, P

    2009-10-01

    Chikungunya fever is an arbovirosis caused by an alphavirus (CHIKV) belonging to the Togaviridae family. Its main vectors are Aedes mosquitoes. In its classic form, Chikungunya consists in a flu-like illness that can be very disabling, especially by incapacitating arthralgia. In children, the arthropathy is well known to be better tolerated than in adulthood but severe manifestations and complications can occur owing to neurologic, cardiac, hematologic or cutaneous dysfunctions, all carrying a fatality risk in the absence of appropriate intensive care. Out of these, the most singular is a severe encephalopathy, even in some cases genuine encephalitis. More rare, but quite specific of small infants, skin blisters have been reported, sometimes complicated by extensive detachments. Mother-to-child infections were demonstrated on La Réunion island with a fifty-percent probability of vertical transmission when the mother was highly viremic around the term of pregnancy. The diagnosis can be made by detecting CHIKV RNA using RT-PCR or specific IgM antibodies using MAC-Elisa serology. Chikungunya is a notifiable disease. The epidemic that emerged in Indian Ocean islands during 2005-2006, its progressive extension to Asia and even to Italy in July 2007, highlighted a very important capacity of CHIKV to cause huge outbreaks wherever Aedes sp. can proliferate. In France, Aedes albopictus is definitively endemic in the departments of Alpes-Maritimes since 2004, Corsica since 2005, and Var since 2007. Therefore, the risk of introduction of CHIKV from an epidemic area to Europe and especially in France is real. PMID:19836680

  2. 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

  3. 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

  4. Gene expression and hepatitis C virus infection

    PubMed Central

    Asselah, T; Bièche, I; Sabbagh, A; Bedossa, P; Moreau, R; Valla, D; Vidaud, M; Marcellin, P

    2009-01-01

    Hepatitis C virus (HCV) is a major cause of chronic liver disease, with about 170 million people infected worldwide. Up to 70% of patients will have persistent infection after inoculation, making this disease a significant cause of morbidity and mortality. The severity of disease varies widely, from asymptomatic chronic infection to cirrhosis and hepatocellular carcinoma. Since the discovery of HCV, the treatment of hepatitis C has considerably improved. Recently, combination of pegylated interferons with ribavirin gives a response rate of about 55%. Treatment is indicated in patients with moderate or severe fibrosis. The tolerability of combination treatment is relatively poor, with a frequent flu-like syndrome and an impaired quality of life. In addition to viral and environmental behavioural factors, host genetic diversity is believed to contribute to the spectrum of clinical outcomes in HCV infection. The sequencing of the human genome, together with the development of high-throughput technologies that measure the function of the genome, have afforded unique opportunities to develop profiles that can distinguish, identify and classify discrete subsets of disease, predict the disease outcome or predict the response to treatment. This paper reviews the published literature on gene expression associated with HCV infection (HCV infection, fibrosis progression), and also according to response to treatment. PMID:19074178

  5. 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

  6. 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

  7. Acute Human Inkoo and Chatanga Virus Infections, Finland.

    PubMed

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

    2016-05-01

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

  8. Acute Human Inkoo and Chatanga Virus Infections, Finland

    PubMed Central

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

    2016-01-01

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

  9. 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

  10. 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

  11. Phosphatidylinositol inhibits respiratory syncytial virus infection

    PubMed Central

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

    2015-01-01

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

  12. 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

  13. 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

  14. Therapy and prophylaxis of Ebola virus infections.

    PubMed

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

    2005-08-01

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

  15. Hepatitis E virus infection in developed countries.

    PubMed

    Miyamura, Tatsuo

    2011-10-01

    Hepatitis E was considered to be endemic infectious disease in developing countries in tropical or subtropical regions with poor sanitary conditions. Large, previously reported outbreaks were mainly due to contaminated water or heavy flooding. Prototype hepatitis E viruses of genotypes I and II were obtained from such endemic cases. In developed countries, in contrast, hepatitis E was rare and diagnosed only in travelers or imported cases. However, the development of accurate diagnostic tests, mainly PCR detection elucidated that autochthonous hepatitis E in developed countries is far more common than previously thought. Although the main route of transmission is food-borne, other routes including blood-borne have been suggested. Recent developments of gene-based diagnostic assays and molecular epidemiology have disclosed the significance of hepatitis E virus infection in developed countries. PMID:21443914

  16. 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

  17. Nipah virus infection in bats (order Chiroptera) in peninsular Malaysia.

    PubMed Central

    Yob, J. M.; Field, H.; Rashdi, A. M.; Morrissy, C.; van der Heide, B.; Rota, P.; bin Adzhar, A.; White, J.; Daniels, P.; Jamaluddin, A.; Ksiazek, T.

    2001-01-01

    Nipah virus, family Paramyxoviridae, caused disease in pigs and humans in peninsular Malaysia in 1998-99. Because Nipah virus appears closely related to Hendra virus, wildlife surveillance focused primarily on pteropid bats (suborder Megachiroptera), a natural host of Hendra virus in Australia. We collected 324 bats from 14 species on peninsular Malaysia. Neutralizing antibodies to Nipah virus were demonstrated in five species, suggesting widespread infection in bat populations in peninsular Malaysia. PMID:11384522

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

    PubMed

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

    1990-09-01

    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. PMID:1698293

  19. 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

  20. 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

  1. Dynamics of perinatal bovine leukemia virus infection

    PubMed Central

    2014-01-01

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

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. Control of immunopathology during chikungunya virus infection.

    PubMed

    Petitdemange, Caroline; Wauquier, Nadia; Vieillard, Vincent

    2015-04-01

    After several decades of epidemiologic silence, chikungunya virus (CHIKV) has recently re-emerged, causing explosive outbreaks and reaching the 5 continents. Transmitted through the bite of Aedes species mosquitoes, CHIKV is responsible for an acute febrile illness accompanied by several characteristic symptoms, including cutaneous rash, myalgia, and arthralgia, with the latter sometimes persisting for months or years. Although CHIKV has previously been known as a relatively benign disease, more recent epidemic events have brought waves of increased morbidity and fatality, leading it to become a serious public health problem. The host's immune response plays a crucial role in controlling the infection, but it might also contribute to the promotion of viral spread and immunopathology. This review focuses on the immune responses to CHIKV in human subjects with an emphasis on early antiviral immune responses. We assess recent developments in the understanding of their possible Janus-faced effects in the control of viral infection and pathogenesis. Although preventive vaccination and specific therapies are yet to be developed, exploring this interesting model of virus-host interactions might have a strong effect on the design of novel therapeutic options to minimize immunopathology without impairing beneficial host defenses. PMID:25843597

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

    PubMed

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

    2014-09-01

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

  10. 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...

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

    PubMed Central

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

    2007-01-01

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

  12. 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 ...

  13. 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) ...

  14. Pathobiology of avian influenza virus infections in wild birds

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    PubMed

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

    2016-01-01

    The number of metagenomic studies conducted each year is growing dramatically. Storage and analysis of such big data is difficult and time-consuming. Interestingly, analysis shows that environmental and human metagenomes include a significant amount of non-annotated sequences, representing a 'dark matter.' We established a bioinformatics pipeline that automatically detects metagenome reads matching query sequences from a given set and applied this tool to the detection of sequences matching large and giant DNA viral members of the proposed order Megavirales or virophages. A total of 1,045 environmental and human metagenomes (≈ 1 Terabase) were collected, processed, and stored on our bioinformatics server. In addition, nucleotide and protein sequences from 93 Megavirales representatives, including 19 giant viruses of amoeba, and 5 virophages, were collected. The pipeline was generated by scripts written in Python language and entitled MG-Digger. Metagenomes previously found to contain megavirus-like sequences were tested as controls. MG-Digger was able to annotate 100s of metagenome sequences as best matching those of giant viruses. These sequences were most often found to be similar to phycodnavirus or mimivirus sequences, but included reads related to recently available pandoraviruses, Pithovirus sibericum, and faustoviruses. Compared to other tools, MG-Digger combined stand-alone use on Linux or Windows operating systems through a user-friendly interface, implementation of ready-to-use customized metagenome databases and query sequence databases, adjustable parameters for BLAST searches, and creation of output files containing selected reads with best match identification. Compared to Metavir 2, a reference tool in viral metagenome analysis, MG-Digger detected 8% more true positive Megavirales-related reads in a control metagenome. The present work shows that massive, automated and recurrent analyses of metagenomes are effective in improving knowledge about the presence and prevalence of giant viruses in the environment and the human body. PMID:27065984

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

    PubMed Central

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

    2016-01-01

    The number of metagenomic studies conducted each year is growing dramatically. Storage and analysis of such big data is difficult and time-consuming. Interestingly, analysis shows that environmental and human metagenomes include a significant amount of non-annotated sequences, representing a ‘dark matter.’ We established a bioinformatics pipeline that automatically detects metagenome reads matching query sequences from a given set and applied this tool to the detection of sequences matching large and giant DNA viral members of the proposed order Megavirales or virophages. A total of 1,045 environmental and human metagenomes (≈ 1 Terabase) were collected, processed, and stored on our bioinformatics server. In addition, nucleotide and protein sequences from 93 Megavirales representatives, including 19 giant viruses of amoeba, and 5 virophages, were collected. The pipeline was generated by scripts written in Python language and entitled MG-Digger. Metagenomes previously found to contain megavirus-like sequences were tested as controls. MG-Digger was able to annotate 100s of metagenome sequences as best matching those of giant viruses. These sequences were most often found to be similar to phycodnavirus or mimivirus sequences, but included reads related to recently available pandoraviruses, Pithovirus sibericum, and faustoviruses. Compared to other tools, MG-Digger combined stand-alone use on Linux or Windows operating systems through a user-friendly interface, implementation of ready-to-use customized metagenome databases and query sequence databases, adjustable parameters for BLAST searches, and creation of output files containing selected reads with best match identification. Compared to Metavir 2, a reference tool in viral metagenome analysis, MG-Digger detected 8% more true positive Megavirales-related reads in a control metagenome. The present work shows that massive, automated and recurrent analyses of metagenomes are effective in improving knowledge about the presence and prevalence of giant viruses in the environment and the human body. PMID:27065984

  17. 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

  18. 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

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

    PubMed Central

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

    2013-01-01

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

  20. Decreased egg production in turkeys experimentally infected with eastern equine encephalitis virus or Highlands J virus.

    PubMed

    Guy, J S; Barnes, H J; Ficken, M D; Smith, L G; Emory, W H; Wages, D P

    1994-01-01

    Turkey breeder hens were experimentally infected with strains of eastern equine encephalitis (EEE) virus or Highlands J (HJ) virus previously isolated from turkey hens experiencing decreased egg production. Depression and inappetance were observed on day 1 postexposure (PE) in hens inoculated with either EEE virus or HJ virus, and egg production fell in each virus-inoculated group from approximately 75% to less than 20% within 2-3 days PE. Egg production remained depressed (less than 20%) for 15 days in EEE-virus-inoculated hens and for 7 days in HJ-virus-inoculated hens. EEE virus and HJ virus were recovered from various tissues on days 1-5 PE, and virus was detected in eggs laid on days 2-5 PE. The findings of this study confirm that EEE virus and HJ virus are potential causes of decreased egg production in turkey breeder hens. PMID:7832710

  1. 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

  2. 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

  3. 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

  4. 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...

  5. Neuralgic amyotrophy and hepatitis E virus infection

    PubMed Central

    van Eijk, Jeroen J.J.; Madden, Richie G.; van der Eijk, Annemiek A.; Hunter, Jeremy G.; Reimerink, Johan H.J.; Bendall, Richard P.; Pas, Suzan D.; Ellis, Vic; van Alfen, Nens; Beynon, Laura; Southwell, Lucy; McLean, Brendan; Jacobs, Bart C.; van Engelen, Baziel G.M.

    2014-01-01

    Objective: To determine whether there is an association between an acute preceding hepatitis E virus (HEV) infection and neuralgic amyotrophy (NA), and if so, whether patients with HEV-related NA differ from patients without an associated HEV infection. Methods: HEV testing was conducted in a retrospective cohort of 28 Cornish patients with NA (2011–2013) and a prospective cohort of 38 consecutive Dutch patients with NA (2004–2007). Acute-phase serum samples were analyzed for the presence of anti-HEV immunoglobulin (Ig) M and IgG and HEV RNA (quantitative real-time PCR). Results: Five cases (10.6%) of acute hepatitis E infection were identified in a total group of 47 patients with NA of whom serum samples were available. In 4 patients, HEV RNA was detected in serum samples taken at presentation. All patients with HEV-associated NA had clinical and electrophysiologic evidence of bilateral brachial plexus involvement. Anti-HEV IgM positivity was not related to age, sex, disease severity, disease course, or outcome. Conclusions: Acute hepatitis E is found in 10% of patients with NA from the United Kingdom and the Netherlands. Further research is required to investigate the role of HEV in NA in other geographical locations and to determine pathophysiologic mechanisms. PMID:24401685

  6. Hepatitis B virus infection and intrahepatic cholangiocarcinoma

    PubMed Central

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

    2014-01-01

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

  7. 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

  8. Persistent Infection of Mice with the Virus of Lymphocytic Choriomeningitis: Virus-Specific Immunological Tolerance

    PubMed Central

    Cihak, Josef; Lehmann-Grube, Fritz

    1974-01-01

    Lymphocytic choriomeningitis (LCM) virus-infected culture cells as targets were markedly reduced in numbers when incubated in vitro with spleen cells from LCM virus-immune mice, even if the cells were taken months after a subcutaneous immunizing infection of the donor animal. Spleen cells from mice persistently infected with LCM virus had no effect on target cells. Also, mitomycin C-blocked LCM virus-infected culture cells stimulated the incorporation of radiolabeled thymidine into spleen cells from LCM virus-immune mice. No stimulation was observed with spleen cells from LCM virus carrier mice. It was concluded that cell-mediated immunity directed against LCM virion surface antigen(s) is absent in LCM virus carrier mice. PMID:16558092

  9. 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

  10. 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

  11. Electron microscope evidence of virus infection in cultured marine fish

    NASA Astrophysics Data System (ADS)

    Sun, Xiu-Qin; Zhang, Jin-Xing; Qu, Ling-Yun

    2000-09-01

    Electron microscope investigation on the red sea bream ( Pagrosomus major), bastard halibut ( Paralichthys olivaceus) and stone flounder ( Kareius bicoloratus) in North China revealed virus infection in the bodies of the dead and diseased fish. These viruses included the lymphocystis disease virus (LDV), parvovirus, globular virus, and a kind of baculavirus which was not discovered and reported before and is now tentatively named baculavirus of stone flounder ( Kareius bicoloratus).

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

    PubMed Central

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

    2012-01-01

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

  13. Amplification of DNA polymerase gene fragments from viruses infecting microalgae.

    PubMed Central

    Chen, F; Suttle, C A

    1995-01-01

    Nested PCR with three highly degenerate primers was used for amplification and identification of DNA polymerase (pol) genes from viruses which infect three genera of microalgae. Group-specific primers (AVS1 and AVS2) were designed on the basis of inferred amino acid sequences unique to the DNA pol genes of viruses (PBCV-1 and NY-2A) that infect an endosymbiotic Chlorella-like alga (Chlorophyceae) and a virus (MpV-SP1) which infects the photosynthetic flagellate Micromonas pusilla (Prasinophyceae). In addition, a nested primer (POL) was designed on the basis of the highly conserved amino acid sequence YGDTDS found in most B-family (alpha-like) DNA pol genes. These primers were used to amplify DNA from the three viruses, PBCV-1, NY-2A, and MpV-SP1, for which the primers were designed, as well as eight clonal isolates of genetically distinct viruses which infect M. pusilla and others which infect Chrysochromulina spp. (Prymnesiophyceae), suggesting that these are a group of related viruses. In contrast, no product resulted from using DNA from viruses which infect the marine brown algae Ectocarpus siliculosis and Feldmannia sp. (Phaeophyceae), suggesting that these viruses may not be closely related to those that infect microalgae. These primers were also used to amplify DNA from natural virus communities. Our results indicate that nested PCR, even under low-stringency conditions, can be used as a rapid method to verify the presence in seawater of a group of related viruses which infect microalgae. Sequence analysis of these fragments should provide information on the genetic diversity and potentially the phyletic relationships among these viruses.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7747950

  14. Amplification of DNA polymerase gene fragments from viruses infecting microalgae.

    PubMed

    Chen, F; Suttle, C A

    1995-04-01

    Nested PCR with three highly degenerate primers was used for amplification and identification of DNA polymerase (pol) genes from viruses which infect three genera of microalgae. Group-specific primers (AVS1 and AVS2) were designed on the basis of inferred amino acid sequences unique to the DNA pol genes of viruses (PBCV-1 and NY-2A) that infect an endosymbiotic Chlorella-like alga (Chlorophyceae) and a virus (MpV-SP1) which infects the photosynthetic flagellate Micromonas pusilla (Prasinophyceae). In addition, a nested primer (POL) was designed on the basis of the highly conserved amino acid sequence YGDTDS found in most B-family (alpha-like) DNA pol genes. These primers were used to amplify DNA from the three viruses, PBCV-1, NY-2A, and MpV-SP1, for which the primers were designed, as well as eight clonal isolates of genetically distinct viruses which infect M. pusilla and others which infect Chrysochromulina spp. (Prymnesiophyceae), suggesting that these are a group of related viruses. In contrast, no product resulted from using DNA from viruses which infect the marine brown algae Ectocarpus siliculosis and Feldmannia sp. (Phaeophyceae), suggesting that these viruses may not be closely related to those that infect microalgae. These primers were also used to amplify DNA from natural virus communities. Our results indicate that nested PCR, even under low-stringency conditions, can be used as a rapid method to verify the presence in seawater of a group of related viruses which infect microalgae. Sequence analysis of these fragments should provide information on the genetic diversity and potentially the phyletic relationships among these viruses.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7747950

  15. Infection of Differentiated Porcine Airway Epithelial Cells by Influenza Virus: Differential Susceptibility to Infection by Porcine and Avian Viruses

    PubMed Central

    Punyadarsaniya, Darsaniya; Liang, Chi-Hui; Winter, Christine; Petersen, Henning; Rautenschlein, Silke; Hennig-Pauka, Isabel; Schwegmann-Wessels, Christel; Wu, Chung-Yi; Wong, Chi-Huey; Herrler, Georg

    2011-01-01

    Background Swine are important hosts for influenza A viruses playing a crucial role in the epidemiology and interspecies transmission of these viruses. Respiratory epithelial cells are the primary target cells for influenza viruses. Methodology/Principal Findings To analyze the infection of porcine airway epithelial cells by influenza viruses, we established precision-cut lung slices as a culture system for differentiated respiratory epithelial cells. Both ciliated and mucus-producing cells were found to be susceptible to infection by swine influenza A virus (H3N2 subtype) with high titers of infectious virus released into the supernatant already one day after infection. By comparison, growth of two avian influenza viruses (subtypes H9N2 and H7N7) was delayed by about 24 h. The two avian viruses differed both in the spectrum of susceptible cells and in the efficiency of replication. As the H9N2 virus grew to titers that were only tenfold lower than that of a porcine H3N2 virus this avian virus is an interesting candidate for interspecies transmission. Lectin staining indicated the presence of both α-2,3- and α-2,6-linked sialic acids on airway epithelial cells. However, their distribution did not correlate with pattern of virus infection indicating that staining by plant lectins is not a reliable indicator for the presence of cellular receptors for influenza viruses. Conclusions/Significance Differentiated respiratory epithelial cells significantly differ in their susceptibility to infection by avian influenza viruses. We expect that the newly described precision-cut lung slices from the swine lung are an interesting culture system to analyze the infection of differentiated respiratory epithelial cells by different pathogens (viral, bacterial and parasitic ones) of swine. PMID:22174804

  16. Multiple virus infections in the honey bee and genome divergence of honey bee viruses.

    PubMed

    Chen, Yanping; Zhao, Yan; Hammond, John; Hsu, Hei-ti; Evans, Jay; Feldlaufer, Mark

    2004-01-01

    Using uniplex RT-PCR we screened honey bee colonies for the presence of several bee viruses, including black queen cell virus (BQCV), deformed wing virus (DWV), Kashmir bee virus (KBV), and sacbrood virus (SBV), and described the detection of mixed virus infections in bees from these colonies. We report for the first time that individual bees can harbor four viruses simultaneously. We also developed a multiplex RT-PCR assay for the simultaneous detection of multiple bee viruses. The feasibility and specificity of the multiplex RT-PCR assay suggests that this assay is an effective tool for simultaneous examination of mixed virus infections in bee colonies and would be useful for the diagnosis and surveillance of honey bee viral diseases in the field and laboratory. Phylogenetic analysis of putative helicase and RNA-dependent RNA polymerase (RdRp) encoded by viruses reveal that DWV and SBV fall into a same clade, whereas KBV and BQCV belong to a distinct lineage with other picorna-like viruses that infect plants, insects and vertebrates. Results from field surveys of these viruses indicate that mixed infections of BQCV, DWV, KBV, and SBV in the honey bee probably arise due to broad geographic distribution of viruses. PMID:15579317

  17. Araçatuba Virus: A Vaccinialike Virus Associated with Infection in Humans and Cattle

    PubMed Central

    de Souza Trindade, Giliane; Guimarães da Fonseca, Flávio; Marques, João Trindade; Nogueira, Maurício Lacerda; Mendes, Luiz Claudio Nogueira; Borges, Alexandre Secorun; Peiró, Juliana Regina; Pituco, Edviges Maristela; Bonjardim, Cláudio Antônio; Ferreira, Paulo César Peregrino

    2003-01-01

    We describe a vaccinialike virus, Araçatuba virus, associated with a cowpoxlike outbreak in a dairy herd and a related case of human infection. Diagnosis was based on virus growth characteristics, electron microscopy, and molecular biology techniques. Molecular characterization of the virus was done by using polymerase chain reaction amplification, cloning, and DNA sequencing of conserved orthopoxvirus genes such as the vaccinia growth factor (VGF), thymidine kinase (TK), and hemagglutinin. We used VGF-homologous and TK gene nucleotide sequences to construct a phylogenetic tree for comparison with other poxviruses. Gene sequences showed 99% homology with vaccinia virus genes and were clustered together with the isolated virus in the phylogenetic tree. Araçatuba virus is very similar to Cantagalo virus, showing the same signature deletion in the gene. Araçatuba virus could be a novel vaccinialike virus or could represent the spread of Cantagalo virus. PMID:12603984

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

    PubMed Central

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

    2015-01-01

    ABSTRACT Marburg virus is a genetically simple RNA virus that causes a severe hemorrhagic fever in humans and nonhuman primates. The mechanism of pathogenesis of the infection is not well understood, but it is well accepted that pathogenesis is appreciably driven by a hyperactive immune response. To better understand the overall response to Marburg virus challenge, we undertook a transcriptomic analysis of immune cells circulating in the blood following aerosol exposure of rhesus macaques to a lethal dose of Marburg virus. Using two-color microarrays, we analyzed the transcriptomes of peripheral blood mononuclear cells that were collected throughout the course of infection from 1 to 9 days postexposure, representing the full course of the infection. The response followed a 3-stage induction (early infection, 1 to 3 days postexposure; midinfection, 5 days postexposure; late infection, 7 to 9 days postexposure) that was led by a robust innate immune response. The host response to aerosolized Marburg virus was evident at 1 day postexposure. Analysis of cytokine transcripts that were overexpressed during infection indicated that previously unanalyzed cytokines are likely induced in response to exposure to Marburg virus and further suggested that the early immune response is skewed toward a Th2 response that would hamper the development of an effective antiviral immune response early in disease. Late infection events included the upregulation of coagulation-associated factors. These findings demonstrate very early host responses to Marburg virus infection and provide a rich data set for identification of factors expressed throughout the course of infection that can be investigated as markers of infection and targets for therapy. IMPORTANCE Marburg virus causes a severe infection that is associated with high mortality and hemorrhage. The disease is associated with an immune response that contributes to the lethality of the disease. In this study, we investigated how the immune cells circulating in the blood of infected primates respond following exposure to Marburg virus. Our results show that there are three discernible stages of response to infection that correlate with presymptomatic, early, and late symptomatic stages of infection, a response format similar to that seen following challenge with other hemorrhagic fever viruses. In contrast to the ability of the virus to block innate immune signaling in vitro, the earliest and most sustained response is an interferon-like response. Our analysis also identifies a number of cytokines that are transcriptionally upregulated during late stages of infection and suggest that there is a Th2-skewed response to infection. When correlated with companion data describing the animal model from which our samples were collected, our results suggest that the innate immune response may contribute to overall pathogenesis. PMID:26202234

  19. 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

  20. Sofosbuvir treatment and hepatitis C virus infection.

    PubMed

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

    2016-01-28

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

  1. Sofosbuvir treatment and hepatitis C virus infection

    PubMed Central

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

    2016-01-01

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

  2. Autophagosomal Protein Dynamics and Influenza Virus Infection

    PubMed Central

    Dumit, Verónica I.; Dengjel, Jörn

    2012-01-01

    Autophagy is a constitutive, catabolic process leading to the lysosomal degradation of cytosolic proteins and organelles. However, it is also induced under stress conditions, remodeling the eukaryotic cell by regulating energy, protein, and lipid homeostasis. It is likely that the autophagosomal/lysosomal pathway evolved primordially to recycle cell components, but further functionally developed as to become part of the immune system to defend against invading pathogens. Likewise, pathogenic, foreign agents developed strategies to fight back and even to employ the autophagy machinery to their own benefit. Hence, the regulation of autophagy has many implications on human health and disease. This review summarizes the molecular dynamics of autophagosome formation, maturation, and target selection. Membrane dynamics, as well as protein–protein and protein–membrane interactions are particularly addressed. In addition, it recapitulates current knowledge of the influences of influenza virus infection on the process. PMID:22566925

  3. Glucose abnormalities in hepatitis C virus infection.

    PubMed

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

    2013-02-01

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

  4. Choclo Virus Infection in the Syrian Golden Hamster

    PubMed Central

    Eyzaguirre, Eduardo J.; Milazzo, Mary Louise; Koster, Frederick T.; Fulhorst, Charles F.

    2009-01-01

    Andes virus and Choclo virus are agents of hantavirus pulmonary syndrome. Andes virus in hamsters almost always causes a disease that is pathologically indistinguishable from fatal hantavirus pulmonary syndrome. The purpose of this study was to assess the pathogenicity of Choclo virus in hamsters. None of 18 hamsters infected with Choclo virus exhibited any symptom of disease. No evidence of inflammation or edema was found in the lungs of the 10 animals killed on days 7, 9, 11, 13, and 16 post-inoculation or in the lungs of the 8 animals killed on day 28 post-inoculation; however, hantavirus antigen was present in large numbers of endothelial cells in the microvasculature of the lungs of the animals killed on days 7, 9, 11, and 13 post-inoculation. These results suggest that infection in the microvasculature of lung tissue alone does not result in the life-threatening pulmonary edema in hamsters infected with Andes virus. PMID:18385367

  5. 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

  6. Antibody dependent enhancement of frog virus 3 infection

    PubMed Central

    2010-01-01

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

  7. 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

  8. 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...

  9. 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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-03-01

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

  12. 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

  13. 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

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

    PubMed

    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

    2009-03-22

    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=10918) 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

  15. Secondary bacterial infections in influenza virus infection pathogenesis.

    PubMed

    Smith, Amber M; McCullers, Jonathan A

    2014-01-01

    Influenza is often complicated by bacterial pathogens that colonize the nasopharynx and invade the middle ear and/or lung epithelium. Incidence and pathogenicity of influenza-bacterial coinfections are multifactorial processes that involve various pathogenic virulence factors and host responses with distinct site- and strain-specific differences. Animal models and kinetic models have improved our understanding of how influenza viruses interact with their bacterial co-pathogens and the accompanying immune responses. Data from these models indicate that considerable alterations in epithelial surfaces and aberrant immune responses lead to severe inflammation, a key driver of bacterial acquisition and infection severity following influenza. However, further experimental and analytical studies are essential to determining the full mechanistic spectrum of different viral and bacterial strains and species and to finding new ways to prevent and treat influenza-associated bacterial coinfections. Here, we review recent advances regarding transmission and disease potential of influenza-associated bacterial infections and discuss the current gaps in knowledge. PMID:25027822

  16. 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

  17. 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

  18. 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

  19. 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

  20. Giant Thyroid Abscess Related to Postpartum Brucella Infection

    PubMed Central

    Akdemir, Zülküf; Karaman, Erbil; Akdeniz, Hüseyin; Alptekin, Cem

    2015-01-01

    Thyroid gland infection, although rare, may be a life threatening disease. Thyroid abscess, arising from acute suppurative thyroiditis (AST), is a rare clinic condition depending on widespread use of antibiotics. Infection may involve one or both lobes and abscess formation may not be apparent until late stage of the progress of illness. Thyroid left lobe is more often affected than the right one. Brucellosis, especially obvious in endemic areas, is a widely seen zoonosis around the world. Although brucella infection can affect many organs through various complications, thyroid gland infection is rare. We aimed to present ultrasonography (USG) and magnetic resonance images (MRI) of a case with an acute thyroiditis which rapidly developed and grew fast on the left half of the neck during the first postpartum month. As far as we know from literature reviewing, our case is the first case report of a thyroid abscess arising from brucella infection which is developed in first postpartum period with images of ultrasonography and MRI. PMID:25861492

  1. Giant thyroid abscess related to postpartum Brucella infection.

    PubMed

    Akdemir, Zülküf; Karaman, Erbil; Akdeniz, Hüseyin; Alptekin, Cem; Arslan, Harun

    2015-01-01

    Thyroid gland infection, although rare, may be a life threatening disease. Thyroid abscess, arising from acute suppurative thyroiditis (AST), is a rare clinic condition depending on widespread use of antibiotics. Infection may involve one or both lobes and abscess formation may not be apparent until late stage of the progress of illness. Thyroid left lobe is more often affected than the right one. Brucellosis, especially obvious in endemic areas, is a widely seen zoonosis around the world. Although brucella infection can affect many organs through various complications, thyroid gland infection is rare. We aimed to present ultrasonography (USG) and magnetic resonance images (MRI) of a case with an acute thyroiditis which rapidly developed and grew fast on the left half of the neck during the first postpartum month. As far as we know from literature reviewing, our case is the first case report of a thyroid abscess arising from brucella infection which is developed in first postpartum period with images of ultrasonography and MRI. PMID:25861492

  2. Experimental infections in man and horses with influenza A viruses*

    PubMed Central

    Kasel, J. A.; Couch, R. B.

    1969-01-01

    The recognition of an antigenic relationship between the haemagglutinins of A/Equi-2 and A2/Hong Kong/68 viruses led to experimental studies in man and horses with these virus types. Human volunteers were inoculated with A/Equi-2/Miami/63 virus and virus shedding ensued in all subjects. The most common clinical response was a febrile illness indistinguishable from naturally occurring human influenza. After administration of A2/Hong Kong/68 virus to 10 ponies there was virus shedding from 9 and a febrile response in 6. When the human subjects previously inoculated with equine virus were challenged with A2/Hong Kong/68 virus, the frequency of illness and the extent of virus shedding were lower than was observed among control individuals. This immunity was found to be related to the level of heterologous serum antibody to the human virus which developed after equine virus infection. Challenge with A/Equi-2/Miami/63 virus of ponies previously inoculated with A2/Hong Kong/68 virus, in the absence of any measurable levels of heterologous antibody to the human strain, resulted in less shedding of virus among these than occurred in control animals. PMID:5309454

  3. The immunogenicity of intracerebral virus infection depends on anatomical site.

    PubMed Central

    Stevenson, P G; Hawke, S; Sloan, D J; Bangham, C R

    1997-01-01

    The brain parenchyma affords immune privilege to tissue grafts, but it is not known whether the same is true for intracerebral viral infections. Using stereotactically guided microinjection, we have confined infection with influenza virus A/NT/60/68 to either the brain parenchyma or the cerebrospinal fluid (CSF). A/NT/60/68 infection in the CSF elicited a comparable immune response to intranasal infection, with the production of antiviral serum antibody, priming of antiviral cytotoxic T-cell precursors, and an antiviral proliferative response in the draining lymph nodes. The response to virus in the CSF was detectable sooner after inoculation than the response to intranasal virus and also involved a prolonged production of virus-specific immunoglobulin A in the CSF. In contrast, there was no detectable immune response to virus infection in the brain parenchyma by any of the parameters measured for at least 10 days after inoculation. Over the next 80 days, 46% of the mice given parenchymal virus developed low-level immune responses that did not involve CSF antibody production, while the remaining 54% had no detectable response at any time. Thus, a virus infection confined to the parenchymal substance of the brain primed the immune system inefficiently or not at all. PMID:8985333

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

    SciTech Connect

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

    1986-11-07

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

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

    PubMed

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

    2015-04-20

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

  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. 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…

  8. The pathogenesis of Epstein-Barr virus persistent infection.

    PubMed

    Thorley-Lawson, David A; Hawkins, Jared B; Tracy, Sean I; Shapiro, Michael

    2013-06-01

    Epstein-Barr virus (EBV) maintains a lifelong infection. According to the germinal center model (GCM), latently infected B cells transit the germinal center (GC) to become resting memory cells. Here, the virus resides quiescently, occasionally reactivating to infect new B cells, completing the cycle of infection. The GCM remains the only model that explains EBV biology and the pathogenesis of lymphoma. Recent work suggests modifications to the model notably that the virus contributes only modestly to the GC process and predictions from mathematical models that quiescence within memory B cells shapes the overall structure of viral infection but is not essential for persistence. Rather, it is the cycle of infection which allows viral persistence at the very low levels observed. PMID:23683686

  9. 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

  10. 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

  11. 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

  12. 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

  13. Encephalomyelitis associated with akabane virus infection in adult cows.

    PubMed

    Lee, J K; Park, J S; Choi, J H; Park, B K; Lee, B C; Hwang, W S; Kim, J H; Jean, Y H; Haritani, M; Yoo, H S; Kim, D Y

    2002-03-01

    Between August and September 2000, five 2-7-year-old cows in Korea exhibited neurologic signs and were diagnosed as infected with Akabane virus based on the results of histopathology, immunohistochemistry, serology, and reverse transcription polymerase chain reaction (RT-PCR) analysis. Immunohistochemistry and RT-PCR were equally effective and sensitive for diagnosing Akabane virus infection during the early stage of infection. Typical lymphohistiocytic inflammation characterized by perivascular mononuclear cell infiltration, gliosis, neuronophagia, and neuronal loss was noted in the brain and the ventral horn gray matter of the spinal cord. The lesions in the brain were most prominent in the pons and medulla oblongata. Akabane virus antigen was detected in the brain and spinal cord, mainly in degenerating neurons and glial cells. RT-PCR analysis revealed a target band of expected size in four cows. This is the first report on an outbreak of natural Akabane virus infection in adult cattle. PMID:12009066

  14. Swine as a model for influenza A virus infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  15. 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...

  16. 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 ...

  17. 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

  18. 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

  19. 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

  20. Monoclonal antibody therapy for Junin virus infection.

    PubMed

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

    2016-04-19

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

  1. Epidemiology of mammalian hepatitis E virus infection.

    PubMed

    Kaba, Mamadou; Moal, Valérie; Gérolami, René; Colson, Philippe

    2013-01-01

    Mammalian hepatitis E virus (HEV), the etiological agent of hepatitis E in humans, is a recently discovered infectious agent. It was identified for the first time in 1983 using electron microscopy on a faecal specimen of a person infected with non-A, non-B enterically-transmitted hepatitis. Based on retrospective and prospective studies, HEV was long described as one of the leading causes of acute viral hepatitis in tropical and subtropical countries, whereas in developed countries hepatitis E was considered an imported disease from HEV hyperendemic countries. Data from studies conducted during the past decade have greatly shifted our knowledge on the epidemiology and clinical spectrum of HEV. Recently, it has been shown that contrary to previous beliefs, hepatitis E is also an endemic disease in several developed countries, particularly in Japan and in Europe, as evidenced by reports of high anti-HEV immunoglobulin G prevalence in healthy individuals and an increasing number of non-travel-related acute hepatitis E cases. Moreover, a porcine reservoir and growing evidence of zoonotic transmission have been reported in these countries. This review summarizes the current knowledge on the epidemiology and prevention of transmission of mammalian HEV. PMID:23343760

  2. Monoclonal antibody therapy for Junin virus infection

    PubMed Central

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

    2016-01-01

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

  3. 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

  4. 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

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

    PubMed

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

    2016-04-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

  8. 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

  9. 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

  10. 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...

  11. 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...

  12. 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

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

    PubMed

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

    2014-01-01

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

  14. 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

  15. 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

  16. 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

  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. Natural infection of turkeys by infectious laryngotracheitis virus.

    PubMed

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

    2008-09-18

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

  19. 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

  20. Experimental Venezuelan Equine Encephalomyelitis Virus Infection of the Bovine

    PubMed Central

    Walton, Thomas E.; Johnson, Karl M.

    1972-01-01

    Two groups of four dairy cows (Bos taurus) were infected subcutaneously with the epizootic Venezuelan equine encephalomyelitis virus (VEE) strains MF-8 and San Pelayo, respectively. Animals experienced no clinical illness, but all developed significant neutropenia. Virus was recovered once each from the blood of three animals but did not exceed 102.2 SMICLD50 (Suckling mouse intracerebral lethal dose50)/ml. Specific neutralizing antibodies appeared in the serum of all animals, but there were no significant differences in titers against different naturally occurring VEE subtypes. Dairy cattle thus appear to play no role in virus transmission during VEE epizootics but may serve as retrospective immunological sentinels of virus activity. PMID:4564396

  1. Human Infection with Orf Virus from Goats in China, 2012

    PubMed Central

    Zhang, Keshan; Liu, Yongjie; Kong, Hanjin; Shang, Youjun

    2014-01-01

    Abstract Orf virus, which belongs to the Parapoxvirus genus, induces a zoonotic infectious disease characterized by acute, highly vascularized cutaneous pustular lesions in sheep and goats. A number of Orf outbreaks have been reported in sheep and goats in recent years, but no reports have described an Orf virus strain from humans in China. In this study, we diagnosed Orf virus infection in two people, a mother and son, in the Gansu province of China. The human Orf virus was isolated and its phylogenetic characterization was analyzed based on a complete B2L gene. The results are useful for developing prospective programs to control Orf virus infections in both goats and humans PMID:24745915

  2. Clinical aspects of feline immunodeficiency and feline leukemia virus infection.

    PubMed

    Hartmann, Katrin

    2011-10-15

    Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) are retroviruses with a global impact on the health of domestic cats. The two viruses differ in their potential to cause disease. FIV can cause an acquired immunodeficiency syndrome that increases the risk of developing opportunistic infections, neurological diseases, and tumors. In most naturally infected cats, however, FIV itself does not cause severe clinical signs, and FIV-infected cats may live many years without any health problems. FeLV is more pathogenic, and was long considered to be responsible for more clinical syndromes than any other agent in cats. FeLV can cause tumors (mainly lymphoma), bone marrow suppression syndromes (mainly anemia) and lead to secondary infectious diseases caused by suppressive effects of the virus on bone marrow and the immune system. Today, FeLV is less important as a deadly infectious agent as in the last 20 years prevalence has been decreasing in most countries. PMID:21807418

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

    PubMed Central

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

    2009-01-01

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

  4. 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...

  5. Neuromuscular Manifestations of West Nile Virus Infection

    PubMed Central

    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–Barré 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

  6. Prior Swine Influenza Virus Infection Enhances Pulmonary Responses to Secondary Haemophilus parasuis Infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Swine Influenza virus (SIV) infection and associated complications are a leading cause of morbidity and mortality. It is appreciated that SIV is often complicated by secondary bacterial infection. Tracheal epithelial cells (TEC) and pulmonary cells respond to infection with proinflammatory cytokin...

  7. Novel H1N1 virus infection and pregnancy.

    PubMed

    Satpathy, Hemant K; Lindsay, Michael; Kawwass, Jennifer F

    2009-11-01

    Human infection with the novel H1N1 influenza virus, initially popularly termed "swine flu," was first reported in April 2009 and has since prompted the World Health Organization (WHO) to raise its pandemic alert to the highest level. During pregnancy both mother and baby are at increased risk when infected with either pandemic or seasonal influenza. Because of concerns about the severity of the disease during pregnancy, the Centers for Disease Control and Prevention (CDC) has implemented enhanced surveillance for infection with this novel virus in pregnant women and has placed them in a group that merits priority vaccine administration. The benefit of treatment with the antiviral medication oseltamivir outweighs its theoretical risk, as pregnant women are at increased risk of severe complications from H1N1 virus infection. In addition to confirmed H1N1 cases, the associated symptoms, particularly fever, merit immediate attention. Moreover, precautions must be taken by both patients and health care professionals when confirmed or suspected H1N1-infected pregnant women present to labor and delivery, or the doctor's office. After delivery, pregnant women infected with H1N1 may breastfeed but must follow specific guidelines. Although the current strain of H1N1 virus has fairly mild sequelae, the virus may have mutated over the summer months and we must anticipate a possible second wave of more severe illness moving into fall 2009 and winter 2010. PMID:19940421

  8. Early Events in Herpes Simplex Virus Infection: a Radioautographic Study

    PubMed Central

    Hummeler, Klaus; Tomassini, Natale; Zajac, Barbara

    1969-01-01

    The early events in herpes simplex virus infection were studied by means of radio-autography. The virus was rapidly taken up by the host cells and uncoated. Viral deoxyribonucleic acid (DNA) reached the nuclear sites of replication in 15 to 30 min after infection. The viral DNA occasionally associated with chromosomes or condensed chromatin but was more frequently found to be randomly distributed. Viral progeny appeared 3 hr after infection. These particles did not show any particular spatial relationship to the parental DNA. The morphological latent period lasted 2.5 hr. Images PMID:4309102

  9. 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

  10. Interferon Response in Hepatitis C Virus (HCV) Infection: Lessons from Cell Culture Systems of HCV Infection

    PubMed Central

    Sung, Pil Soo; Shin, Eui-Cheol; Yoon, Seung Kew

    2015-01-01

    Hepatitis C virus (HCV) is a positive-stranded RNA virus that infects approximately 130–170 million people worldwide. In 2005, the first HCV infection system in cell culture was established using clone JFH-1, which was isolated from a Japanese patient with fulminant HCV infection. JFH-1 replicates efficiently in hepatoma cells and infectious virion particles are released into the culture supernatant. The development of cell culture-derived HCV (HCVcc) systems has allowed us to understand how hosts respond to HCV infection and how HCV evades host responses. Although the mechanisms underlying the different outcomes of HCV infection are not fully understood, innate immune responses seem to have a critical impact on the outcome of HCV infection, as demonstrated by the prognostic value of IFN-λ gene polymorphisms among patients with chronic HCV infection. Herein, we review recent research on interferon response in HCV infection, particularly studies using HCVcc infection systems. PMID:26457705

  11. Interferon Response in Hepatitis C Virus (HCV) Infection: Lessons from Cell Culture Systems of HCV Infection.

    PubMed

    Sung, Pil Soo; Shin, Eui-Cheol; Yoon, Seung Kew

    2015-01-01

    Hepatitis C virus (HCV) is a positive-stranded RNA virus that infects approximately 130-170 million people worldwide. In 2005, the first HCV infection system in cell culture was established using clone JFH-1, which was isolated from a Japanese patient with fulminant HCV infection. JFH-1 replicates efficiently in hepatoma cells and infectious virion particles are released into the culture supernatant. The development of cell culture-derived HCV (HCVcc) systems has allowed us to understand how hosts respond to HCV infection and how HCV evades host responses. Although the mechanisms underlying the different outcomes of HCV infection are not fully understood, innate immune responses seem to have a critical impact on the outcome of HCV infection, as demonstrated by the prognostic value of IFN-λ gene polymorphisms among patients with chronic HCV infection. Herein, we review recent research on interferon response in HCV infection, particularly studies using HCVcc infection systems. PMID:26457705

  12. Basal Autophagy Is Required for Herpes simplex Virus-2 Infection

    PubMed Central

    Yakoub, Abraam M.; Shukla, Deepak

    2015-01-01

    Autophagy is a conserved catabolic process of the cell, which plays an important role in regulating plethora of infections. The role of autophagy in Herpes simplex virus-2 (HSV-2) infection is unknown. Here, we found that HSV-2 does not allow induction of an autophagic response to infection, but maintains basal autophagy levels mostly unchanged during productive infection. Thus, we investigated the importance of basal autophagy for HSV-2 infection, using pharmacological autophagy suppression or cells genetically deficient in an autophagy-essential gene (ATG5). Interference with basal autophagy flux in cells significantly reduced viral replication and diminished the infection. These results indicate that basal autophagy plays an indispensable role required for a productive infection. Importantly, this study draws a sharp distinction between induced and basal autophagy, where the former acts as a viral clearance mechanism abrogating infection, while the latter supports infection. PMID:26248741

  13. 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

  14. Prevalence of Hepatitis δ (Delta) Virus Infection A Seroepidemiologic Study

    PubMed Central

    DeCock, Kevin M.; Jones, Brenda; Govindarajan, Sugantha; Redeker, Allan G.

    1988-01-01

    In assessing the prevalence of hepatitis δ (delta) virus (HDV) infection in 358 patients with acute hepatitis B seen in Los Angeles between 1983 and 1985 and in 196 patients with chronic hepatitis B followed between 1980 and 1985, we found that 23% of patients with chronic and 5% of patients with acute hepatitis B were infected with HDV. Among patients with chronic hepatitis B, the prevalence of HDV infection was 73% in intravenous drug users and 14% in homosexual men. Acute coinfection with the hepatitis B virus was also more frequent in drug users (8%) than in other groups. δ-Hepatitis is a common infection in hepatitis B virus carriers in Los Angeles, particularly in drug addicts, but also in homosexual men who do not abuse drugs intravenously. PMID:3363963

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

  16. 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

  17. Early Events in Chikungunya Virus Infection-From Virus Cell Binding to Membrane Fusion.

    PubMed

    van Duijl-Richter, Mareike K S; Hoornweg, Tabitha E; Rodenhuis-Zybert, Izabela A; Smit, Jolanda M

    2015-07-01

    Chikungunya virus (CHIKV) is a rapidly emerging mosquito-borne alphavirus causing millions of infections in the tropical and subtropical regions of the world. CHIKV infection often leads to an acute self-limited febrile illness with debilitating myalgia and arthralgia. A potential long-term complication of CHIKV infection is severe joint pain, which can last for months to years. There are no vaccines or specific therapeutics available to prevent or treat infection. This review describes the critical steps in CHIKV cell entry. We summarize the latest studies on the virus-cell tropism, virus-receptor binding, internalization, membrane fusion and review the molecules and compounds that have been described to interfere with virus cell entry. The aim of the review is to give the reader a state-of-the-art overview on CHIKV cell entry and to provide an outlook on potential new avenues in CHIKV research. PMID:26198242

  18. 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.

  19. Acute Epstein-Barr virus infection complicated by severe thrombocytopenia.

    PubMed

    Pipp, M L; Means, N D; Sixbey, J W; Morris, K L; Gue, C L; Baddour, L M

    1997-11-01

    We describe one patient with acute Epstein-Barr virus (EBV) infection associated with severe thrombocytopenia and review 36 additional cases reported in the literature. Complications of EBV infection due to severe thrombocytopenia occurred in 10 (27.0%) of 37 patients, and 2 (5.4%) of 37 patients died. Although acute EBV infections are generally benign and self-limiting, thrombocytopenia, a potentially serious complication, should not be overlooked. PMID:9402388

  20. Simian Virus 40 Infection in the Spinal Cord of Simian Immunodeficiency Virus-Immunosuppressed Rhesus Macaques.

    PubMed

    Kaliyaperumal, Saravanan; Wüthrich, Christian; Westmoreland, Susan V; Koralnik, Igor J

    2015-11-01

    Progressive multifocal leukoencephalopathy (PML) is an often-fatal demyelinating disease of the CNS that usually develops in immunocompromised individuals because of reactivation of quiescent JC virus (JCV). There are only a few reports of JCV infection in the human spinal cord. Progressive multifocal leukoencephalopathy-like demyelinating lesions have been documented in the brains of simian immunodeficiency virus-infected macaques. To determine whether simian virus 40 (SV40) can infect and cause PML lesions in spinal cords of immunosuppressed macaques, we examined archival spinal cord samples from 15 simian immunodeficiency virus-infected rhesus monkeys with acquired immunodeficiency syndrome and SV40 infection of the brain. Among those, 6 (40%) had SV40-infected cells in the spinal cord, including 1 with PML-like lesions, 1 with PML-like lesions and meningoencephalitis, 2 with meningoencephalitis, 1 with gray matter gliosis, and 1 with no lesions. One animal with a large PML-like lesion had extensive demyelination and SV40 infection of astrocytes, oligodendrocytes, and meningeal cells. None of the 6 animals had SV40-infected spinal cord neurons. These observations indicate that, like JCV in immunosuppressed humans, SV40 can infect glial cells and cause PML-like lesions in the spinal cord of immunosuppressed rhesus macaques. Rhesus macaques could serve as an animal model to study polyomavirus infection and pathogenesis in the spinal cord. PMID:26469249

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

    PubMed

    Chen, Hui-Lan; Tang, Ren-Bin

    2016-04-01

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

  2. 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

  3. 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

  4. 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....

  5. 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

  6. 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

  7. Antiviral activity of lanatoside C against dengue virus infection.

    PubMed

    Cheung, Yan Yi; Chen, Karen Caiyun; Chen, Huixin; Seng, Eng Khuan; Chu, Justin Jang Hann

    2014-11-01

    Dengue infection poses a serious threat globally due to its recent rapid spread and rise in incidence. Currently, there is no approved vaccine or effective antiviral drug for dengue virus infection. In response to the urgent need for the development of an effective antiviral for dengue virus, the US Drug Collection library was screened in this study to identify compounds with anti-dengue activities. Lanatoside C, an FDA approved cardiac glycoside was identified as a candidate anti-dengue compound. Our data revealed that lanatoside C has an IC50 of 0.19μM for dengue virus infection in HuH-7 cells. Dose-dependent reduction in dengue viral RNA and viral proteins synthesis were also observed upon treatment with increasing concentrations of lanatoside C. Time of addition study indicated that lanatoside C inhibits the early processes of the dengue virus replication cycle. Furthermore, lanatoside C can effectively inhibit all four serotypes of dengue virus, flavivirus Kunjin, alphavirus Chikungunya and Sindbis virus as well as the human enterovirus 71. These findings suggest that lanatoside C possesses broad spectrum antiviral activity against several groups of positive-sense RNA viruses. PMID:25251726

  8. 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.

  9. 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

  10. Rapid diagnosis of parainfluenza virus infection in children.

    PubMed Central

    Wong, D T; Welliver, R C; Riddlesberger, K R; Sun, M S; Ogra, P L

    1982-01-01

    The indirect immunofluorescent-antibody (IFA) assay for detection of parainfluenza virus antigen was performed on samples of nasopharyngeal secretions obtained from infants and children with various respiratory illnesses to determine the usefulness of the IFA assay for rapid diagnosis of parainfluenza virus infection. Ninety-four samples of nasopharyngeal secretions were obtained from 78 children during a community outbreak of parainfluenza virus infection. Application of the IFA assay revealed the presence of parainfluenza antigen in 67 of the 94 samples. When these same specimens were inoculated into tissue culture, the presence of parainfluenza virus was confirmed in 62 (93%) of the 67 IFA-positive specimens by hemadsorption on tissue culture monolayers (31 cases), presence of parainfluenza hemagglutinin in infected tissue culture fluids (23 cases), or by other methods (8 cases). Only four IFA-negative specimens were subsequently shown to be positive for parainfluenza virus by tissue culture infectivity. The IFA assay provided a more rapid and more accurate method for diagnosis of parainfluenza infection in children than did routine tissue culture methods employed currently. PMID:6286717

  11. 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

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

    PubMed Central

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

    2009-01-01

    Alpha-herpesviruses, including human herpes simplex virus 1 & 2, varicella zoster virus and the swine pseudorabies virus (PRV), infect the peripheral nervous system of their hosts. Symptoms of infection often include itching, numbness, or pain indicative of altered neurological function. To determine if there is an in vitro electrophysiological correlate to these characteristic in vivo symptoms, we infected cultured rat sympathetic neurons with well-characterized strains of PRV known to produce virulent or attenuated symptoms in animals. Whole-cell patch clamp recordings were made at various times after infection. By 8 hours of infection with virulent PRV, action potential (AP) firing rates increased substantially and were accompanied by hyperpolarized resting membrane potentials and spikelet-like events. Coincident with the increase in AP firing rate, adjacent neurons exhibited coupled firing events, first with AP-spikelets and later with near identical resting membrane potentials and AP firing. Small fusion pores between adjacent cell bodies formed early after infection as demonstrated by transfer of the low molecular weight dye, Lucifer Yellow. Later, larger pores formed as demonstrated by transfer of high molecular weight Texas red-dextran conjugates between infected cells. Further evidence for viral-induced fusion pores was obtained by infecting neurons with a viral mutant defective for glycoprotein B, a component of the viral membrane fusion complex. These infected neurons were essentially identical to mock infected neurons: no increased AP firing, no spikelet-like events, and no electrical or dye transfer. Infection with PRV Bartha, an attenuated circuit-tracing strain delayed, but did not eliminate the increased neuronal activity and coupling events. We suggest that formation of fusion pores between infected neurons results in electrical coupling and elevated firing rates, and that these processes may contribute to the altered neural function seen in PRV-infected animals. PMID:19876391

  13. 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

  14. 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

  15. 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 μg 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

  16. Epstein-Barr Virus (EBV): infection, propagation, quantitation, and storage.

    PubMed

    Lan, Ke; Verma, Subhash C; Murakami, Masanao; Bajaj, Bharat; Robertson, Erle S

    2007-08-01

    Epstein-Barr virus (EBV) was first reported as the etiological agent of Burkitt's lymphoma in 1964. Since then, EBV has also been associated with nasopharyngeal carcinoma, which is highly prevalent in Southeast Asia, as well as infectious mononucleosis, complications of AIDS, and transplant-related B cell lymphomas. This virus has further been linked with T cell lymphomas and Hodgkin's disease, establishing the concept of a wide spectrum of EBV-associated malignant disorders. So far, there are a number of EBV-infected cell lines established that can be induced for production of infectious viral progeny and that facilitate the study of the mechanism of EBV-related infection, transformation, and oncogenesis. This unit describes procedures for the preparation of EBV virion particles and in vitro infection of cells with EBV. In addition, procedures for quantitation and storage of the virus are provided. PMID:18770612

  17. 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

  18. 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.

  19. 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

  20. Antibody landscapes after influenza virus infection or vaccination

    PubMed Central

    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.; 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.

    2014-01-01

    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 six years and for 225 individuals pre- and post-vaccination. On 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 use of an antigenically advanced virus had the dual benefit of inducing antibodies against both advanced and previous antigenic clusters. These results indicate that pre-emptive vaccine updates may improve influenza vaccine efficacy in previously-exposed individuals. PMID:25414313

  1. 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

  2. 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

  3. Pneumonia Virus of Mice Severe Respiratory Virus Infection in a Natural Host

    PubMed Central

    Rosenberg, Helene F.; Domachowske, Joseph B.

    2008-01-01

    Pneumonia virus of mice (PVM; family Paramyxoviridae, genus Pneumovirus) is a natural mouse pathogen that is closely related to the human and bovine respiratory syncytial viruses. Among the prominent features of this infection, robust replication of PVM takes place in bronchial epithelial cells in response to a minimal virus inoculum. Virus replication in situ results in local production of proinflammatory cytokines (MIP-1α, MIP-2, MCP-1 and IFNγ) and granulocyte recruitment to the lung. If left unchecked, PVM infection and the ensuing inflammatory response ultimately lead to pulmonary edema, respiratory compromise and death. In this review, we consider the recent studies using the PVM model that have provided important insights into the role of the inflammatory response in the pathogenesis of severe respiratory virus infection. We also highlight several works that have elucidated acquired immune responses to this pathogen, including T cell responses and the development of humoral immunity. Finally, we consider several immunomodulatory strategies that have been used successfully to reduce morbidity and mortality when administered to PVM infected, symptomatic mice, and thus hold promise as realistic therapeutic strategies for severe respiratory virus infections in human subjects. PMID:18471897

  4. 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

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

    PubMed

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

    2012-10-01

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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

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

    PubMed

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

    2015-04-01

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

  12. 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

  13. 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

  14. 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

  15. Effect of cacao husk extract on human immunodeficiency virus infection.

    PubMed

    Unten, S; Ushijima, H; Shimizu, H; Tsuchie, H; Kitamura, T; Moritome, N; Sakagami, H

    1991-12-01

    A sodium hydroxide extract from cacao husk inhibited the cytopathic effect of human immunodeficiency virus type 1 (HIV-1) against HTLV-1-transformed T-cell lines MT-2 and MT-4. It also inhibited syncytium formation between HIV-infected and uninfected lymphoblastoid T-cell line, MOLT-4. The anti-HIV activity was concentrated by membrane filter fractionation to a fraction with molecular weight of 100-300 KDa. Anti-HIV activity of the extract was attributable to interference with the virus adsorption, rather than to inhibition of the virus replication after adsorption. PMID:1367748

  16. 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

  17. Infection and immunity with a virus isolate from turkeys.

    PubMed

    Winterfield, R W; Reed, W M; Thacker, H L

    1985-11-01

    Avian pox virus was isolated from cutaneous pox lesions removed from turkey breeders that had been vaccinated three times with a commercial fowl pox vaccine. In three cross-immunization experiments with turkeys and two with chickens, the turkey pox isolate, designated NC5271, proved immunologically different from fowl, pigeon, and quail pox viruses. Significant protection against NC5271 virus infection and inducement of pox lesions was only attained when the homologous isolate was used as a vaccine. The potential need in the field for such a vaccine was discussed. PMID:2999743

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

    PubMed Central

    Filée, Jonathan

    2015-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  20. 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

  1. 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

  2. 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

  3. Hepatitis C Virus Infection: Looking for Interferon Free Regimens

    PubMed Central

    González-Moreno, J.; Payeras-Cifre, A.

    2013-01-01

    Recent developments of new drugs' combinations are changing the treatment paradigm in hepatitis C virus infection. Due to the side effect profile of pegylated interferons, interferon-sparing regimens have become the main target in chronic hepatitis C treatment research. Recent proofs of concept studies have suggested that cure of chronic hepatitis C can be achieved without interferon. The purpose of this paper is to provide an overview of the clinical results recently reported for the treatment of hepatitis C virus infection with interferon-free regimens, focusing on the most promising new compounds and combinations. PMID:23710151

  4. 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

  5. Herpes Simplex Virus Products in Productive and Abortive Infection

    PubMed Central

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

    1968-01-01

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  7. 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

  8. 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

  9. 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

  10. 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

  11. Adaptive immune response during hepatitis C virus infection

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    1995-01-01

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

  13. 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

  14. Experimental Infection of Horses with West Nile virus

    PubMed Central

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

    2002-01-01

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

  15. Microglial activation induces neuronal death in Chandipura virus infection.

    PubMed

    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

  16. 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

  17. 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

  18. Fatal Cowpox Virus Infection in an Aborted Foal.

    PubMed

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

    2016-06-01

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

  19. 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

  20. 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

  1. Generation of transforming viruses in cultures of chicken fibroblasts infected with an avian leukosis virus.

    PubMed Central

    Stavnezer, E; Gerhard, D S; Binari, R C; Balazs, I

    1981-01-01

    During serial passages of an avian leukosis virus (the transformation-defective, src deletion mutant of Bratislava 77 avian sarcoma virus, designated tdB77) in chicken embryo fibroblasts, viruses which transformed chicken embryo fibroblasts in vitro emerged. Chicken embryo fibroblasts infected with these viruses (SK770 and Sk780) had a distinctive morphology, formed foci in monolayer cultures, and grew independent of anchorage in semisolid agar. Bone marrow cells were not transformed by these viruses. Another virus (SK790) with similar properties emerged during serial subcultures of chicken embryo fibroblasts after a single infection with tdB77. The 50S to RNAs isolated from these viruses contained a tdB77-sized genome (7.6 kilobases), 8.7- and 5.7-kilobase RNAs, and either a 4.1-kilobase RNA or a 4.6-kilobase RNA. These RNAs did not hybridize with cDNA's representing the src, erb, mac, and myb genes of avian acute transforming viruses. Cells transformed by any one of the Sk viruses (SK770, SK780, or SK790) synthesized two novel gag-related polyproteins having molecular weights of 110,000 (p110) and 125,000 (p125). We investigated the compositions of these proteins with monospecific antiviral protein sera. We found that p110 was a gag-pol fusion protein which contained antigenic determinants, leaving 49,000 daltons which was antigenically unrelated to the structural and replicative proteins of avian leukosis viruses. An analysis of the SK viral RNAs with specific DNA probes indicated that the 5.7-kilobase RNA contained gag sequences but lacked pol sequences and, therefore, probably encoded p125. The transforming ability, the deleted genome, and the induced polyproteins of the SK viruses were reminiscent of the properties of several replication-defective acute transforming viruses. Images PMID:6169846

  2. 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

  3. 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...

  4. 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

  5. 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

  6. Alteration of cell cycle progression by Sindbis virus infection

    SciTech Connect

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

    2015-07-10

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

  7. 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

  8. 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

  9. Animal Models of Chronic Hepatitis Delta Virus Infection Host–Virus Immunologic Interactions

    PubMed Central

    Aldabe, Rafael; Suárez-Amarán, Lester; Usai, Carla; González-Aseguinolaza, Gloria

    2015-01-01

    Hepatitis delta virus (HDV) is a defective RNA virus that has an absolute requirement for a virus belonging to the hepadnaviridae family like hepatitis B virus (HBV) for its replication and formation of new virions. HDV infection is usually associated with a worsening of HBV-induced liver pathogenesis, which leads to more frequent cirrhosis, increased risk of hepatocellular carcinoma (HCC), and fulminant hepatitis. Importantly, no selective therapies are available for HDV infection. The mainstay of treatment for HDV infection is pegylated interferon alpha; however, response rates to this therapy are poor. A better knowledge of HDV–host cell interaction will help with the identification of novel therapeutic targets, which are urgently needed. Animal models like hepadnavirus-infected chimpanzees or the eastern woodchuck have been of great value for the characterization of HDV chronic infection. Recently, more practical animal models in which to perform a deeper study of host virus interactions and to evaluate new therapeutic strategies have been developed. Therefore, the main focus of this review is to discuss the current knowledge about HDV host interactions obtained from cell culture and animal models. PMID:25686091

  10. Role of Regulatory T Cells during Virus Infection

    PubMed Central

    Veiga-Parga, Tamara; Sehrawat, Sharvan; Rouse, Barry T.

    2013-01-01

    Summary The host response to viruses includes multiple cell types that have regulatory function. Most information focuses on CD4+ regulatory T cells that express the transcription factor Foxp3+ (Tregs), which are the topic of this review. We explain how viruses through specific and non-specific means can trigger the response of thymus-derived natural Tregs as well as induce Tregs. The latter derive under appropriate stimulation conditions either from uncommitted precursors or from differentiated cells that convert to become Tregs. We describe instances where Tregs appear to limit the efficacy of antiviral protective immunity and other perhaps more common immune-mediated inflammatory conditions, where the Tregs function to limit the extent of tissue damage that occurs during a virus infection. We discuss the controversial roles that Tregs may play in the pathogenesis of human immunodeficiency and hepatitis C virus infections. The issue of plasticity is discussed, since this may result in Tregs losing their protective function when present in inflammatory environments. Finally, we mention approaches used to manipulate Treg numbers and function and assess their current value and likely future success to manage the outcome of virus infection, especially those that are responsible for chronic tissue damage. PMID:23947355

  11. Discovery of mammalian genes that participate in virus infection

    PubMed Central

    Organ, Edward L; Sheng, Jinsong; Ruley, H Earl; Rubin, Donald H

    2004-01-01

    Background Viruses are obligate intracellular parasites that rely upon the host cell for different steps in their life cycles. The characterization of cellular genes required for virus infection and/or cell killing will be essential for understanding viral life cycles, and may provide cellular targets for new antiviral therapies. Results Candidate genes required for lytic reovirus infection were identified by tagged sequence mutagenesis, a process that permits rapid identification of genes disrupted by gene entrapment. One hundred fifty-one reovirus resistant clones were selected from cell libraries containing 2 × 105 independently disrupted genes, of which 111 contained mutations in previously characterized genes and functionally anonymous transcription units. Collectively, the genes associated with reovirus resistance differed from genes targeted by random gene entrapment in that known mutational hot spots were under represented, and a number of mutations appeared to cluster around specific cellular processes, including: IGF-II expression/signalling, vesicular transport/cytoskeletal trafficking and apoptosis. Notably, several of the genes have been directly implicated in the replication of reovirus and other viruses at different steps in the viral lifecycle. Conclusions Tagged sequence mutagenesis provides a rapid, genome-wide strategy to identify candidate cellular genes required for virus infection. The candidate genes provide a starting point for mechanistic studies of cellular processes that participate in the virus lifecycle and may provide targets for novel anti-viral therapies. PMID:15522117

  12. 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

  13. Potent neutralizing monoclonal antibodies against Ebola virus infection

    PubMed Central

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

    2016-01-01

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

  14. Potent neutralizing monoclonal antibodies against Ebola virus infection.

    PubMed

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

    2016-01-01

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

  15. Lethal Nipah Virus Infection Induces Rapid Overexpression of CXCL10

    PubMed Central

    Mathieu, Cyrille; Guillaume, Vanessa; Sabine, Amélie; 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

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

    PubMed Central

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

    2016-01-01

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

  17. Herpes simplex virus-1 and varicella virus infections in familial dysautonomia patients.

    PubMed

    Maayan, C; Nimrod, A; Morag, A; Becker, Y

    1998-03-01

    Familial dystautonomia (FD) patients are deficient in type C fibers, suggesting that there may be a different pattern of infection and clinical presentation when infected by Herpes simplex virus type 1 (HSV-1) or Varicella-Zoster virus (VZV). These viruses infect and are reactivated in the periphery of the body through type C sensory nerve fibers. HSV-1 infects epithelial cells, penetrates into type C fibers, and migrates to the ganglia to generate latent infection. In reactivation, the viral DNA migrates through type C fibers, infecting the epidermis at the entry site. VZV infects through the respiratory tract, causing systemic viral infection and latency in the ganglia, from which it is reactivated and reaches the skin. The study was carried by clinical questionnaire and by HSV and VZV IgG antibodies on fifty-one FD patients and eighty matched controls. The questionnaire revealed that no FD patient had a history of clinical HSV-1 infection, compared to 15% in the control group (P < 0.05), while 50% FD patients had been infected by varicella, compared to 66% in the VZV control group. However in FD, VZV clinical manifestations were mild in comparison to controls. There was no difference in infection rates for some other viral diseases. HSV-1 antibodies were detected in 24% of the FD patients, compared to 38% in the control group (P < 0.1). VZV antibodies were similar in FD and controls (66%, 63%). We concluded that the rate of HSV infection in FD is low and clinical reactivation is rare. The rate of varicella infection appears to be the same for patients and controls, but in FD the clinical presentation is mild. We suggest that these differences are due to the lack of type C fibers in FD patients. PMID:9515762

  18. 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.

  19. 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...

  20. Aquagenic urticaria and human immunodeficiency virus infection: treatment with stanozolol.

    PubMed

    Fearfield, L A; Gazzard, B; Bunker, C B

    1997-10-01

    We report the first case of aquagenic urticaria in a patient with human immunodeficiency virus (HIV) infection. This is a rare physical urticaria not previously described in this context. The disorder proved unamenable to conventional treatment with antihistamines, but did respond dramatically to stanozolol, suggesting a novel indication for this anabolic steroid. PMID:9390343

  1. 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

  2. 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

  3. 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

  4. Retinochoroiditis in acute Epstein-Barr virus infection.

    PubMed Central

    Kelly, S P; Rosenthal, A R; Nicholson, K G; Woodward, C G

    1989-01-01

    The case is reported of a 17-year-old male with secondary glaucoma and retinochoroiditis complicating acute clinical infectious mononucleosis. The diagnosis was confirmed by Epstein-Barr virus specific serology. Toxoplasmic infection was initially suspected. The differential diagnosis and relevant literature are discussed. Images PMID:2611181

  5. 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...

  6. 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...

  7. 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

  8. 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...

  9. Current Approaches for Diagnosis of Influenza Virus Infections in Humans

    PubMed Central

    Vemula, Sai Vikram; Zhao, Jiangqin; Liu, Jikun; Wang, Xue; Biswas, Santanu; Hewlett, Indira

    2016-01-01

    Despite significant advancement in vaccine and virus research, influenza continues to be a major public health concern. Each year in the United States of America, influenza viruses are responsible for seasonal epidemics resulting in over 200,000 hospitalizations and 30,000–50,000 deaths. Accurate and early diagnosis of influenza viral infections are critical for rapid initiation of antiviral therapy to reduce influenza related morbidity and mortality both during seasonal epidemics and pandemics. Several different approaches are currently available for diagnosis of influenza infections in humans. These include viral isolation in cell culture, immunofluorescence assays, nucleic acid amplification tests, immunochromatography-based rapid diagnostic tests, etc. Newer diagnostic approaches are being developed to overcome the limitations associated with some of the conventional detection methods. This review discusses diagnostic approaches currently available for detection of influenza viruses in humans. PMID:27077877

  10. Current Approaches for Diagnosis of Influenza Virus Infections in Humans.

    PubMed

    Vemula, Sai Vikram; Zhao, Jiangqin; Liu, Jikun; Wang, Xue; Biswas, Santanu; Hewlett, Indira

    2016-01-01

    Despite significant advancement in vaccine and virus research, influenza continues to be a major public health concern. Each year in the United States of America, influenza viruses are responsible for seasonal epidemics resulting in over 200,000 hospitalizations and 30,000-50,000 deaths. Accurate and early diagnosis of influenza viral infections are critical for rapid initiation of antiviral therapy to reduce influenza related morbidity and mortality both during seasonal epidemics and pandemics. Several different approaches are currently available for diagnosis of influenza infections in humans. These include viral isolation in cell culture, immunofluorescence assays, nucleic acid amplification tests, immunochromatography-based rapid diagnostic tests, etc. Newer diagnostic approaches are being developed to overcome the limitations associated with some of the conventional detection methods. This review discusses diagnostic approaches currently available for detection of influenza viruses in humans. PMID:27077877

  11. 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

  12. 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

  13. Examining Human T-Lymphotropic Virus Type 1 Infection and Replication by Cell-Free Infection with Recombinant Virus Vectors

    PubMed Central

    Derse, David; Hill, Shawn A.; Lloyd, Patricia A.; Chung, Hye-kyung; Morse, Barry A.

    2001-01-01

    A sensitive and quantitative cell-free infection assay, utilizing recombinant human T-cell leukemia virus type 1 (HTLV-1)-based vectors, was developed in order to analyze early events in the virus replication cycle. Previous difficulties with the low infectivity and restricted expression of the virus have prevented a clear understanding of these events. Virus stocks were generated by transfecting cells with three plasmids: (i) a packaging plasmid encoding HTLV-1 structural and regulatory proteins, (ii) an HTLV-1 transfer vector containing either firefly luciferase or enhanced yellow fluorescent protein genes, and (iii) an envelope expression plasmid. Single-round infections were initiated by exposing target cells to filtered supernatants and quantified by assaying for luciferase activity in cell extracts or by enumerating transduced cells by flow cytometry. Transduction was dependent on reverse transcription and integration of the recombinant virus genome, as shown by the effects of the reverse transcriptase inhibitor 3′-azido-3′-deoxythymidine (AZT) and by mutation of the integrase gene in the packaging vector, respectively. The 50% inhibitory concentration of AZT was determined to be 30 nM in this HTLV-1 replication system. The stability of HTLV-1 particles, pseudotyped with either vesicular stomatitis virus G protein or HTLV-1 envelope, was typical of retroviruses, exhibiting a half-life of approximately 3.5 h at 37°C. The specific infectivity of recombinant HTLV-1 virions was at least 3 orders of magnitude lower than that of analogous HIV-1 particles, though both were pseudotyped with the same envelope. Thus, the low infectivity of HTLV-1 is determined in large part by properties of the core particle and by the efficiency of postentry processes. PMID:11507191

  14. 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

  15. 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

  16. Association of inconclusive sera for human immunodeficiency virus infection with malaria and Epstein-Barr virus infection in Central Africa.

    PubMed

    Mbopi-Keou, Francois-Xavier; Ndjoyi-Mbiguino, Angélique; Talla, Frédéric; Péré, Hélène; Kebe, Khady; Matta, Mathieu; Sosso, Maurice Aurelien; Bélec, Laurent

    2014-02-01

    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

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

    PubMed Central

    Ndjoyi-Mbiguino, Angélique; Talla, Frédéric; Péré, Hélène; Kebe, Khady; Matta, Mathieu; Sosso, Maurice Aurelien; Bélec, 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

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

    MedlinePlus

    ... About RSV Infection and Incidence Symptoms and Care Transmission and Prevention For Healthcare Professionals Research & Surveillance Trends and Surveillance RSV in Alaskan Natives History Multimedia References & Resources Infographic Related Links Related Links ...

  19. 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

  20. Equine influenza A(H3N8) virus infection in cats.

    PubMed

    Su, Shuo; Wang, Lifang; Fu, Xinliang; He, Shuyi; Hong, Malin; Zhou, Pei; Lai, Alexander; Gray, Gregory; Li, Shoujun

    2014-12-01

    Interspecies transmission of equine influenza A(H3N8) virus has resulted in establishment of a canine influenza virus. To determine if something similar could happen with cats, we experimentally infected 14 cats with the equine influenza A(H3N8) virus. All showed clinical signs, shed virus, and transmitted the virus to a contact cohort. PMID:25417790

  1. Equine Influenza A(H3N8) Virus Infection in Cats

    PubMed Central

    Su, Shuo; Wang, Lifang; Fu, Xinliang; He, Shuyi; Hong, Malin; Zhou, Pei; Gray, Gregory

    2014-01-01

    Interspecies transmission of equine influenza A(H3N8) virus has resulted in establishment of a canine influenza virus. To determine if something similar could happen with cats, we experimentally infected 14 cats with the equine influenza A(H3N8) virus. All showed clinical signs, shed virus, and transmitted the virus to a contact cohort. PMID:25417790

  2. 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

  3. Common occurrence of concurrent infections by multiple dengue virus serotypes.

    PubMed

    Loroño-Pino, M A; Cropp, C B; Farfán, J A; Vorndam, A V; Rodríguez-Angulo, E M; Rosado-Paredes, E P; Flores-Flores, L F; Beaty, B J; Gubler, D J

    1999-11-01

    The co-circulation of all 4 dengue virus serotypes in the same community, common since the 1950s in Southeast Asia, has now become a frequent occurrence in many Caribbean Islands, Mexico, and Central and South America in the past 20 years. As a consequence, the frequency of concurrent infections would be expected to increase in these areas. To assess this, using state of the art technology, we screened viremic serum samples and mosquitoes inoculated with serum samples collected during epidemics involving multiple dengue virus serotypes in Indonesia, Mexico, and Puerto Rico for virus isolation. Of 292 samples tested, 16 (5.5%) were found to contain 2 or more dengue viruses by an indirect immunofluorescence test and/or the reverse transcriptase-polymerase chain reaction. PMID:10586902

  4. 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

  5. A conservation law for virus infection kinetics in vitro.

    PubMed

    Kakizoe, Yusuke; Morita, Satoru; Nakaoka, Shinji; Takeuchi, Yasuhiro; Sato, Kei; Miura, Tomoyuki; Beauchemin, Catherine A A; Iwami, Shingo

    2015-07-01

    Conservation laws are among the most important properties of a physical system, but are not commonplace in biology. We derived a conservation law from the basic model for viral infections which consists in a small set of ordinary differential equations. We challenged the conservation law experimentally for the case of a virus infection in a cell culture. We found that the derived, conserved quantity remained almost constant throughout the infection period, implying that the derived conservation law holds in this biological system. We also suggest a potential use for the conservation law in evaluating the accuracy of experimental measurements. PMID:25882746

  6. Human Immunodeficiency Virus Infection-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

  7. Atypical Presentations of Respiratory Syncytial Virus Infection: Case Series.

    PubMed

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

    2016-02-01

    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

  8. 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

  9. Effect of lithium in murine immunodeficiency virus infected animals.

    PubMed

    Gallicchio, V S; Cibull, M L; Hughes, N K; Tse, K F

    1993-01-01

    Murine AIDS (MAIDS) is a disease that shows many similarities to human HIV infection. The etiological agent of MAIDS is a defective murine leukemia virus that seems to be able to induce disease in the absence of viral replication. This animal model has been useful in stimulating the search of answers to questions and the formation of new hypotheses related to human AIDS. The monovalent cation lithium can influence a number of immunohematopoietic cell types and cellular processes where proliferation and differentiation occur. We describe here the result of in vivo studies investigating the effect of lithium treatment on MAIDS-infected mice. Viral control and lithium-treated animals were monitored for survival and development of MAIDS pathology. MAIDS animals treated with lithium demonstrated a marked reduction in their development of lymphadenopathy and splenomegaly. Both MAIDS control and lithium-treated virus-infected mice developed evidence of lymphoma; however, the involvement was much more massive both at the gross and microscopic levels in the MAIDS control compared with the lithium-treated mice. These data suggest that lithium may be effective in modulating murine immunodeficiency virus infection and raise important questions related to the potential role lithium may play in the pathophysiological processes associated with retroviral infections. PMID:8216844

  10. 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

  11. Viruses in fungi: infection of yeast with the K1 and K2 killer viruses.

    PubMed Central

    el-Sherbeini, M; Bostian, K A

    1987-01-01

    We demonstrate here that yeast killer viruses, previously thought to be transmitted only by cytoplasmic mixing during division, mating, or other induced forms of cell fusion, are capable of extracellular transmission. Viral particles from standard K1 and K2 killer strains were used to inoculate sensitive cells of Saccharomyces cerevisiae, rendered competent by spheroplasting, lithium acetate treatment, or by natural mating. Extracellular transmission of the killer viruses was judged by the following criteria and controls. Filter-sterilized virus inocula were shown to be free of viable yeast cells, and host cells treated in the absence of added virus did not yield killer progeny. Infected clones originating from spheroplasts or lithium acetate-treated cells were shown to possess the genotype of the host strain and the killer phenotype of the infecting virus. Infected clones derived from complementary mating pairs were found to be wild-type diploids, whose meiotic segregants exhibited 2:2 segregation for unlinked nutritional markers and 4:0 segregation for the killer phenotype. This technique is generally applicable to the study of interactions between yeast viruses and different hosts and suggests that extracellular transmission may be a natural route for the inheritance and dissemination of mycoviruses. Images PMID:3295880

  12. Cutaneous Co-infected Cytomegalovirus and Herpes Simplex Virus Perigenital Ulcers in Human Immunodeficiency Virus Patients.

    PubMed

    Schoenfeld, Jason; Cannon, Sarah; Cam, Kristin; Keller, Matthew

    2013-10-01

    There is uncertainty regarding the pathogenic nature of cytomegalovirus in cutaneous lesions co-infected with herpes simplex virus. It is widely believed that herpes simplex virus is the main pathogenic factor in such lesions and that cytomegalovirus plays little if any role. There are, however, isolated case reports that describe cytomegalovirus as an important driving pathogen in such lesions. The authors present two human immunodeficiency virus patients who have cytomegalovirus and herpes simplex virus co-infected perigenital ulcers, one of whom improved on valacyclovir, while the other, who was already on valacyclovir for chronic herpes simplex virus suppression, showed no improvement with a single dose of cidofovir. He only showed rapid improvement when treated with valganciclovir. The latter patient underscores the viewpoint that at least in some cases, cytomegalovirus may be an important driving force behind the formation of such lesions. The authors therefore recommend that clinicians be aware of the possible pathogenic role of cytomegalovirus in these ulcers, and, in nonhealing ulcers, use anti-cytomegalovirus agents to prevent the onset of systemic disease. These results warrant further study of the pathogenesis of cytomegalovirus in co-infected herpes simplex virus ulcers. PMID:24155993

  13. 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

  14. An improved syncytia infectivity assay for the bovine leukemia virus.

    PubMed

    Diglio, C A; Piper, C E; Ferrer, J F

    1978-06-01

    Several factors that influence the sensitivity of the syncytia infectivity assay for the bovine leukemia virus (BLV) and BLV-infected lymphocytes have been examined. The use of early-passage indicator bovine embryonic spleen (BESP) cells and their pretreatment with diethylamino-ethyl-dextran (DEAE-D) was essential for optimal sensitivity. Polybrene was less effective than DEAE-D. The combination of DEAE-D and polybrene was more effective than DEAE-D alone when BLV-infected leukocytes were used as the inoculum, but not when the inoculum was a cell-free BLV preparation. Using BESP cell passages 4 to 11 as indicators, reproducible titers were obtained when aliquots of the same virus stock were assayed at different times after freezer storage. When assaying peripheral blood lymphocytes from infected cattle, optimal syncytia responses were observed consistently by inoculating 5 X 10(6) viable lymphocytes per 60-mm Falcon dish. Centrifugation of peripheral blood leukocytes from BLV-infected cattle in discontinuous bovine serum albumin gradients can be used to separate a subpopulation of infected lymphocytes. Use of this subpopulation as the inoculum, rather than unseparated buffy-coat leukocytes, greatly increases the sensitivity of the syncytia infectivity assay. PMID:210107

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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

  3. Ex vivo infection of live tissue with oncolytic viruses.

    PubMed

    Diallo, Jean-Simon; Roy, Dominic; Abdelbary, Hesham; De Silva, Naomi; Bell, John C

    2011-01-01

    Oncolytic Viruses (OVs) are novel therapeutics that selectively replicate in and kill tumor cells(1). Several clinical trials evaluating the effectiveness of a variety of oncolytic platforms including HSV, Reovirus, and Vaccinia OVs as treatment for cancer are currently underway(2-5). One key characteristic of oncolytic viruses is that they can be genetically modified to express reporter transgenes which makes it possible to visualize the infection of tissues by microscopy or bio-luminescence imaging(6,7). This offers a unique advantage since it is possible to infect tissues from patients ex vivo prior to therapy in order to ascertain the likelihood of successful oncolytic virotherapy(8). To this end, it is critical to appropriately sample tissue to compensate for tissue heterogeneity and assess tissue viability, particularly prior to infection(9). It is also important to follow viral replication using reporter transgenes if expressed by the oncolytic platform as well as by direct titration of tissues following homogenization in order to discriminate between abortive and productive infection. The object of this protocol is to address these issues and herein describes 1. The sampling and preparation of tumor tissue for cell culture 2. The assessment of tissue viability using the metabolic dye alamar blue 3. Ex vivo infection of cultured tissues with vaccinia virus expressing either GFP or firefly luciferase 4. Detection of transgene expression by fluorescence microscopy or using an In Vivo Imaging System (IVIS) 5. Quantification of virus by plaque assay. This comprehensive method presents several advantages including ease of tissue processing, compensation for tissue heterogeneity, control of tissue viability, and discrimination between abortive infection and bone fide viral replication. PMID:21730946

  4. Treating hepatitis C virus infection in active substance users.

    PubMed

    Sylvestre, Diana L

    2005-04-15

    Although injection drug users represent the majority of new and existing cases of infection with hepatitis C virus (HCV), many lack access to treatment because of concerns about adherence, effectiveness, and reinfection. On the basis of on a small but increasing body of evidence showing that injection drug users can undergo treatment for HCV infection successfully, the 2002 National Institutes of Health Consensus Statement on Hepatitis C has recommended that substance users be treated for HCV infection on a case-by-case basis. However, the criteria on which these treatment decisions should be made are unclear. The duration of pretreatment abstinence, concurrent psychiatric illness, intervening drug use, and the potential for injected interferon to cause relapse of drug use may all influence results of treatment for HCV infection. This overview presents preliminary data on the impact of these potential barriers on outcomes of treatment for HCV infection. PMID:15768341

  5. 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

  6. Hepatitis C Virus Infection and Its Rheumatologic Implications

    PubMed Central

    Sayiner, Zeynel A.; Haque, Uzma; Malik, Mohammad U.

    2014-01-01

    Extrahepatic manifestations are frequently encountered among patients with chronic hepatitis C virus (HCV) infection. Many of these manifestations are autoimmune disorders, with added mortality and morbidity due to involvement of multiple organ systems. Symptoms of HCV infection and rheumatic diseases may be similar and include arthralgia, myalgia, arthritis, and vasculitis. Also, serologic abnormalities may be found in both cases. Some treatment modalities for HCV infection, including interferon therapy, may aggravate the symptoms of rheumatic diseases, thus confounding clinical presentation. It is imperative to distinguish whether symptoms such as arthralgia, myalgia, and arthritis occur in patients with HCV infection due to primary chronic HCV infection or to a newly developed rheumatologic disease process. PMID:24987312

  7. 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

  8. Bacterial vaginosis and human immunodeficiency virus infection

    PubMed Central

    Spear, Gregory T; St John, Elizabeth; Zariffard, M Reza

    2007-01-01

    Epidemiologic studies indicate that bacterial vaginosis (BV), a common alteration of lower genital tract flora in women, is associated with increased susceptibility to HIV infection. Other recent studies show that HIV is detected more frequently and at higher levels in the lower genital tract of HIV-seropositive women with BV. In vitro studies show that genital tract secretions from women with BV or flora associated with BV induce HIV expression in infected cells. The increased HIV expression appears to be due at least in part to activation through Toll-like receptors (TLR), specifically TLR2. Further research is needed to elucidate how BV contributes to HIV acquisition and transmission. PMID:17953761

  9. 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

  10. Individual Correlates of Infectivity of Influenza A Virus Infections in Households

    PubMed Central

    Tsang, Tim K.; Fang, Vicky J.; Chan, Kwok-Hung; Ip, Dennis K. M.; Leung, Gabriel M.; Peiris, J. S. Malik; Cauchemez, Simon

    2016-01-01

    Background Identifying individual correlates of infectivity of influenza virus is important for disease control and prevention. Viral shedding is used as a proxy measure of infectivity in many studies. However, the evidence for this is limited. Methods In a detailed study of influenza virus transmission within households in 2008–12, we recruited index cases with confirmed influenza infection from outpatient clinics, and followed up their household contacts for 7–10 days to identify secondary infections. We used individual-based hazard models to characterize the relationship between individual viral shedding and individual infectivity. Results We analyzed 386 households with 1147 household contacts. Index cases were separated into 3 groups according to their estimated level of viral shedding at symptom onset. We did not find a statistically significant association of virus shedding with transmission. Index cases in medium and higher viral shedding groups were estimated to have 21% (95% CI: -29%, 113%) and 44% (CI: -16%, 167%) higher infectivity, compared with those in the lower viral shedding group. Conclusions Individual viral load measured by RT-PCR in the nose and throat was at most weakly correlated with individual infectivity in households. Other correlates of infectivity should be examined in future studies. PMID:27153194

  11. 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

  12. 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

  13. 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

  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. Determination of Baylisascaris schroederi Infection in Wild Giant Pandas by an Accurate and Sensitive PCR/CE-SSCP Method

    PubMed Central

    Zhang, Wenping; Yie, Shangmian; Yue, Bisong; Zhou, Jielong; An, Renxiong; Yang, Jiangdong; Chen, Wangli; Wang, Chengdong; Zhang, Liang; Shen, Fujun; Yang, Guangyou; Hou, Rong; Zhang, Zhihe

    2012-01-01

    It has been recognized that other than habitat loss, degradation and fragmentation, the infection of the roundworm Baylisascaris schroederi (B. schroederi) is one of the major causes of death in wild giant pandas. However, the prevalence and intensity of the parasite infection has been inconsistently reported through a method that uses sedimentation-floatation followed by a microscope examination. This method fails to accurately determine infection because there are many bamboo residues and/or few B. schroederi eggs in the examined fecal samples. In the present study, we adopted a method that uses PCR and capillary electrophoresis combined with a single-strand conformation polymorphism analysis (PCR/CE-SSCP) to detect B. schroederi infection in wild giant pandas at a nature reserve, and compared it to the traditional microscope approach. The PCR specifically amplified a single band of 279-bp from both fecal samples and positive controls, which was confirmed by sequence analysis to correspond to the mitochondrial COII gene of B. schroederi. Moreover, it was demonstrated that the amount of genomic DNA was linearly correlated with the peak area of the CE-SSCP analysis. Thus, our adopted method can reliably detect the infectious prevalence and intensity of B. schroederi in wild giant pandas. The prevalence of B. schroederi was found to be 54% in the 91 fecal samples examined, and 48% in the fecal samples of 31 identified individual giant pandas. Infectious intensities of the 91 fecal samples were detected to range from 2.8 to 959.2 units/gram, and from 4.8 to 959.2 units/gram in the fecal samples of the 31 identified giant pandas. For comparison, by using the traditional microscope method, the prevalence of B. schroederi was found to be only 33% in the 91 fecal samples, 32% in the fecal samples of the 31 identified giant pandas, and no reliable infectious intensity was observed. PMID:22911871

  16. 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

  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. 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

  19. 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.

  20. Concomitant Human Infections with 2 Cowpox Virus Strains in Related Cases, France, 2011

    PubMed Central

    Ducournau, Corinne; Ferrier-Rembert, Audrey; Ferraris, Olivier; Joffre, Aurélie; Favier, Anne-Laure; Flusin, Olivier; Van Cauteren, Dieter; Kecir, Kaci; Auburtin, Brigitte; Védy, Serge; Bessaud, Maël

    2013-01-01

    We investigated 4 related human cases of cowpox virus infection reported in France during 2011. Three patients were infected by the same strain, probably transmitted by imported pet rats, and the fourth patient was infected by another strain. The 2 strains were genetically related to viruses previously isolated from humans with cowpox infection in Europe. PMID:24274113

  1. Characterization of Lethal Zika Virus Infection in AG129 Mice

    PubMed Central

    Walker, Emma C.; Larkin, Katrina E.; Camacho, Erwin; Osorio, Jorge E.

    2016-01-01

    Background Mosquito-borne Zika virus (ZIKV) typically causes a mild and self-limiting illness known as Zika fever, which often is accompanied by maculopapular rash, headache, and myalgia. During the current outbreak in South America, ZIKV infection during pregnancy has been hypothesized to cause microcephaly and other diseases. The detection of ZIKV in fetal brain tissue supports this hypothesis. Because human infections with ZIKV historically have remained sporadic and, until recently, have been limited to small-scale epidemics, neither the disease caused by ZIKV nor the molecular determinants of virulence and/or pathogenicity have been well characterized. Here, we describe a small animal model for wild-type ZIKV of the Asian lineage. Methodology/Principal Findings Using mice deficient in interferon α/β and Ɣ receptors (AG129 mice), we report that these animals were highly susceptible to ZIKV infection and disease, succumbing within seven to eight days. Rapid viremic dissemination was observed in visceral organs and brain; but only was associated with severe pathologies in the brain and muscle. Finally, these results were consistent across challenge routes, age of mice, and inoculum doses. These data represent a mouse model for ZIKV that is not dependent on adapting ZIKV to intracerebral passage in mice. Conclusions/Significance Foot pad injection of AG129 mice with ZIKV represents a biologically relevant model for studying ZIKV infection and disease development following wild-type virus inoculation without the requirement for adaptation of the virus or intracerebral delivery of the virus. This newly developed Zika disease model can be exploited to identify determinants of ZIKV virulence and reveal molecular mechanisms that control the virus-host interaction, providing a framework for rational design of acute phase therapeutics and for vaccine efficacy testing. PMID:27093158

  2. [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

  3. 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

  4. Herpes simplex virus 2 infection impacts stress granule accumulation.

    PubMed

    Finnen, Renée L; Pangka, Kyle R; Banfield, Bruce W

    2012-08-01

    Interference with stress granule (SG) accumulation is gaining increased appreciation as a common strategy used by diverse viruses to facilitate their replication and to cope with translational arrest. Here, we examined the impact of infection by herpes simplex virus 2 (HSV-2) on SG accumulation by monitoring the localization of the SG components T cell internal antigen 1 (TIA-1), Ras-GTPase-activating SH3-domain-binding protein (G3BP), and poly(A)-binding protein (PABP). Our results indicate that SGs do not accumulate in HSV-2-infected cells and that HSV-2 can interfere with arsenite-induced SG accumulation early after infection. Surprisingly, SG accumulation was inhibited despite increased phosphorylation of eukaryotic translation initiation factor 2α (eIF2α), implying that HSV-2 encodes previously unrecognized activities designed to maintain translation initiation downstream of eIF2α. SG accumulation was not inhibited in HSV-2-infected cells treated with pateamine A, an inducer that works independently of eIF2α phosphorylation. The SGs that accumulated following pateamine A treatment of infected cells contained G3BP and PABP but were largely devoid of TIA-1. We also identified novel nuclear structures containing TIA-1 that form late in infection. These structures contain the RNA binding protein 68-kDa Src-associated in mitosis (Sam68) and were noticeably absent in infected cells treated with inhibitors of viral DNA replication, suggesting that they arise as a result of late events in the virus replicative cycle. PMID:22623775

  5. Hepatitis during respiratory syncytial virus infection – a case report

    PubMed Central

    Kirin, Branka Kristić; Topić, Renata Zrinski; Dodig, Slavica

    2013-01-01

    Introduction: Respiratory syncytial virus (RSV) infection is the most common cause of hospitalization in infants and small children. The aim was to present a 13-months old boy diagnosed with acute airway infection, acute otitis media (AOM) and hepatitis during the RSV-infection. Material and methods: Serum catalytic activities of alkaline phosphatase (ALP), aspartate aminotranspherase (AST), alanine aminotranspherase (ALT), gamma glutamyl transpherase (GGT), lactate dehydrogenase (LD), and concentrations of bilirubin were monitored during hospitalization and at control examination. Results: The child had clinical signs and symptoms of respiratory failure, AOM, and laboratory findings of virus infection and liver disease. On admission, catalytic activities of enzymes were markedly increased, especially the activity of ALP (10333 U/L, i.e. 24-fold increase in comparison with the upper reference limit). The highest increased in AST (339 U/L, 4.5-fold), ALT (475 U/L, 10.3-fold) and LD (545 U/L, 1.5-fold) were registered on the 3rd day, and the highest increase in GGT (68 U/L, 3.1-fold) occurred on the 11th day. Seven weeks after discharge AST, ALT, GGT and LD decreased into reference range, and ALP remain mildly increased (478 U/L, 1.1 fold increase). RSV was confirmed in nasal lavage fluid. Conclusion: Laboratory results in patient with RSV infection needs to be interpreted in the light of both, respiratory and extrapulmonary manifestations of the infection, respectively. PMID:23457772

  6. Frontiers in the Treatment of Hepatitis C Virus Infection

    PubMed Central

    Ahn, Joseph

    2014-01-01

    In the United States, chronic hepatitis C virus (HCV) infection is the leading cause of blood-borne, virus-associated death related to advanced liver disease and the leading indication for liver transplantation. Although the diagnostic test for HCV has been available for more than 20 years, the majority of persons with HCV infection still have not received a diagnosis. This has led to a recent change in screening recommendations by the Centers for Disease Control and Prevention. Moreover, new medications were approved in 2011 after nearly a decade of minimal progress in the development of treatments for HCV infection. This was followed by the highly anticipated approval of sofosbuvir and simeprevir in 201 3. In the past 3 years, there has been an explosion of reports on medications from different classes, promising a dramatic expansion to an all-oral regimen for the treatment of HCV genotype 1 infection within the next few years. This article reviews the current screening recommendations and standard of care for treatment of HCV infection and highlights specific agents in the pipeline that should change the landscape of how HCV infection is treated in the near future. PMID:24803873

  7. Genetics of natural resistance to Sendai virus infection in mice.

    PubMed Central

    Brownstein, D G

    1983-01-01

    The genetics of resistance to a naturally occurring respiratory infection caused by Sendai virus was examined in F1, F2, and backcross progeny of resistant C57BL/6J and susceptible DBA/2J mice and in 25 recombinant inbred strains. An intranasal inoculum of 0.1 50% tissue culture infective dose (low dose) of Sendai virus caused 0% mortality in C57BL/6J and F1 mice and 73% mortality in DBA/2J mice. An inoculum of 1.0 50% tissue culture infective dose (high dose) caused 3, 0, and 89% mortality in C57BL/6J, F1, and DBA/2J mice, respectively. Low-dose infection caused 36% mortality in F1 X DBA/2J hybrids and 0% mortality in F2 hybrids. High-dose infection caused 29 and 32% mortality in F1 X DBA/2J and F2 hybrids, respectively. Resistance was not linked to H-2 haplotype, coat color, or sex. High-dose infection caused deaths in 12 recombinant inbred strains, and the strain distribution pattern was concordant with that of a chromosome 1 marker, Sas-1, in 20 of 25 strains (P less than 0.01). Resistance therefore behaved as a simple Mendelian dominant trait which presumptively mapped to chromosome 1. PMID:6305840

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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

  15. Previous infection protects house finches from re-infection with St. Louis encephalitis virus.

    PubMed

    Reisen, W K; Chiles, R E; Green, E N; Fang, Y; Mahmood, F

    2003-05-01

    Antibody titers against St. Louis encephalitis virus (SLE) measured by a plaque reduction neutralization test (PRNT) decreased rapidly in house finches (Capodacus mexicanus) after initial infection, whereas antibodies measured by enzyme immunoassay (EIA) remained detectable in all birds for the length of the experiment, indicating long-term persistence and greater assay sensitivity of the EIA. After 52 wk, birds were challenged by subcutaneous inoculation with the same strain of SLE virus. Virus was not detected for 1-4 d postchallenge in blood samples tested by plaque assay and RT-PCR or by xenodiagnosis in Culex tarsalis fed concurrently and then held for 11 d at 26 degrees C. Virus was detected by all three methods in control birds infected concurrently for the first time. Challenge with SLE produced a rapid and marked ananmestic rise in both neutralizing and EIA antibody titers that exceeded the primary response in the same birds or in concurrently inoculated control birds. At necropsy 4 wk postchallenge, 3 of 7 challenged and 1 of 2 positive control birds were chronically infected, with viral RNA detected by RT-PCR in brain, spleen, lung, and/or kidney tissues. Our results indicated that persistence of protective antibody prevents reinfection during the following season and may prevent the recrudescence of infectious virus in chronically infected birds. PMID:12943108

  16. Pathogenesis of Lassa virus infection in guinea pigs.

    PubMed Central

    Jahrling, P B; Smith, S; Hesse, R A; Rhoderick, J B

    1982-01-01

    A rodent model for human Lassa fever was developed which uses inbred (strain 13) and outbred (Hartley) guinea pigs. Strain 13 guinea pigs were uniformly susceptible to lethal infection by 2 or more PFU of Lassa virus strain Josiah. In contrast, no more than 30% of the Hartley guinea pigs died regardless of the virus dose. In lethally infected strain 13 guinea pigs, peak titers of virus (10(7) to 10(8) PFU) occurred in the spleen and lymph nodes at 8 to 9 days, in the salivary glands at 11 days, and in the lung at 14 to 16 days. Virus reached low titers (10(4) PFU) in the plasma and brain and intermediate titers in the liver, adrenal glands, kidney, pancreas, and heart. In moribund animals, the most consistent and severe histological lesion as an interstitial pneumonia. In contrast, the brain was only minimally involved. The immune response of lethally infected strain 13 guinea pigs, as measured by the indirect fluorescent antibody test, was detectable within 10 days of infection and was similar in timing and intensity to the fluorescent antibody test response of both lethally infected and surviving outbred animals. In contrast to the fluorescent antibody response, neutralizing antibody developed late in convalescence and was thus detected only in surviving outbred guinea pigs. The availability of a rodent model for human Lassa fever in uniformly susceptible strain 13 guinea pigs should facilitate detailed pathophysiological studies and efficacy testing of antiviral drugs, candidate vaccines, and immunotherapy regimens to develop control methods for this life-threatening disease in humans. Images PMID:6749685

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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

  3. Hepatitis A virus infections in Voyvodina.

    PubMed Central

    Vuković, B. S.; Rončević, N.; Borota, R.; Terzin, A. L.

    1981-01-01

    Sera of 1000 persons in Voyvodina were tested with radioimmunoassay for antibodies against hepatitis A virus (HAV). The morbidity and age incidence of positive findings have been analysed and compared with relevant findings in other countries. Below the age of 19 years the morbidity rates are higher (0.138 to 0.595 per mill) and the prevalences of seropositives are lower (17.1-64.0%) than the respective frequencies above that age (0.011 to 0.052 per mill and 85.7-98.7% respectively). Below the first year of life seropositivity is more frequent than in 1- to 14-year old children. After the first year until the age of 30-39 years the frequency of seropositives increases with increasing age up to a maximum of about 90%. PMID:6257777

  4. West Nile Virus Infection of Birds, Mexico

    PubMed Central

    Guerrero-Sánchez, Sergio; Cuevas-Romero, Sandra; Nemeth, Nicole M.; Trujillo-Olivera, María Teresa Jesús; Worwa, Gabriella; Dupuis, Alan; Brault, Aaron C.; Kramer, Laura D.; Komar, Nicholas

    2011-01-01

    West Nile virus (WNV) has caused disease in humans, equids, and birds at lower frequency in Mexico than in the United States. We hypothesized that the seemingly reduced virulence in Mexico was caused by attenuation of the Tabasco strain from southeastern Mexico, resulting in lower viremia than that caused by the Tecate strain from the more northern location of Baja California. During 2006–2008, we tested this hypothesis in candidate avian amplifying hosts: domestic chickens, rock pigeons, house sparrows, great-tailed grackles, and clay-colored thrushes. Only great-tailed grackles and house sparrows were competent amplifying hosts for both strains, and deaths occurred in each species. Tecate strain viremia levels were higher for thrushes. Both strains produced low-level viremia in pigeons and chickens. Our results suggest that certain avian hosts within Mexico are competent for efficient amplification of both northern and southern WNV strains and that both strains likely contribute to bird deaths. PMID:22172633

  5. 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

  6. 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

  7. [The role of Epstein-Barr virus infections in human pathology].

    PubMed

    Vujosević, M; Gvozdenović, E

    1994-01-01

    Epstein-Barr virus (EBV) belongs to the group of herpesvirus and may remain latent after primary infection with a possibility of periodical reactivation EBV infection is transmitted by intimate, oral contact with previously infected persons, persons sick or infected earlier which secrete virus periodically. We report on pathogenesis of primary infection as well as clinical characteristics of infective mononucleosis and other EBV associated diseases (Birkitt lymphoma, nasopharyngeal carcinoma, syndrome of chronical fatigue). PMID:7476696

  8. 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

  9. Is virus coinfection a predictor of severity in children with viral respiratory infections?

    PubMed

    Asner, S A; Rose, W; Petrich, A; Richardson, S; Tran, D J

    2015-03-01

    Molecular assays have resulted in increased detection of viral respiratory infections, including virus coinfection, from children with acute respiratory infections. Yet the clinical severity of virus coinfection compared to single virus infection remains uncertain. We performed a retrospective study of children presenting with acute respiratory infections comparing clinical severity of single respiratory virus infection to virus coinfection, detected on midturbinate swabs by molecular assays. Patient characteristics and measures of clinical severity were abstracted from health records. A total of 472 virus-infected children were included, 391 with a single virus infection and 81 with virus coinfection. Virus status did not affect admission to hospital (odds ratio (OR) = 0.8; 95 % confidence interval (CI) 0.5-1.4; p 0.491) or clinical disease severity among inpatients (OR = 0.8; 95% CI 0.5-1.5; p 0.515) after adjusting for age and underlying comorbidities. However, children infected with rhinovirus/enterovirus (HRV/ENT) alone were more likely to be admitted to the hospital compared to those coinfected with HRV/ENT and at least another virus, although this was not significant in multivariable analyses (OR 0.47; 95% CI 0.22-1.0; p 0.051). In multivariable analyses, children coinfected with respiratory syncytial virus (RSV) and other viruses were significantly more likely to present with radiologically confirmed pneumonia compared to those with an isolated RSV infection (OR 3.16, 95% CI 1.07-9.34, p 0.037). Equivalent clinical severity was observed between children with single virus infection and virus coinfection, although children coinfected with RSV and other viruses presented more frequently with pneumonia than those with single RSV infection. Increased disease severity observed among children with single HRV/ENT infection requires further investigation. PMID:25596778

  10. [Hepatitis B Virus Infection: Current Trends and Issues].

    PubMed

    Furusyo, Norihiro; Shimizu, Motohiro; Ogawa, Eijchi; Murata, Masayuki; Hayashi, Jun

    2015-06-01

    Hepatitis B virus (HBV) infection is a global public health problem. HBV has been classified into eight genotypes (A to H) based on complete nucleotide sequencing. The prevalence of specific genotype varies geographically. The rationale for treatment in patients with chronic hepatitis B is to reduce the risk of progressive chronic liver disease, such as cirrhosis and hepatocellular carcinoma. Treatment strategies for chronic HBV infection include interferon and nucleotide analogues (lamivudine, adefovir dipivoxil, entecavir, and tenofovir disoproxil). HBV persists in the body even after serological recovery from acute hepatitis B. Thus, individuals who have been exposed to HBV are at risk of the reactivation of infection, which may result in an increase in serum aminotransferases or a flare when the immune response is suppressed. Patients requiring immunosuppressive therapy should undergo serologic testing for markers of HBV infection. This topic review summarizes these issues related to the management of hepatitis B. PMID:26548241

  11. Trends in human immunodeficiency virus infection: epidemiology in Singapore.

    PubMed

    Chew, S K

    1993-03-01

    The acquired immunodeficiency syndrome (AIDS), caused by the human immunodeficiency virus (HIV) and recognised a decade ago, has reached pandemic proportions worldwide. By early 1992, the World Health Organisation estimates that at least 10 to 12 million people are infected with HIV globally. The majority of these infections are the result of heterosexual transmission. In South and South-east Asia, the AIDS pandemic is growing rapidly due to intravenous drug use and heterosexual transmission. Since 1985, the major route of HIV transmission in Singapore has been sexual. The transmission pattern, however, has changed from one that was predominantly homosexual or bisexual to one that is increasingly heterosexual from mid-1990. In addition, HIV infections among intravenous drug users, children and organ recipients who received transplantation overseas have also surfaced since 1990. It is estimated that there will be 400 cases of HIV infection in Singapore by the mid-1990s. PMID:8363325

  12. Prevention and management of neonatal herpes simplex virus infections

    PubMed Central

    Allen, Upton D; Robinson, Joan L

    2014-01-01

    Human herpes simplex virus (HSV) infection in neonates can result in devastating outcomes, including mortality and significant morbidity. All infants are potentially at risk for neonatal HSV infection. This position statement reviews epidemiology, transmission and risk factors, with a focus on intrapartum infection. It considers diagnosis and prognosis according to infection category, along with testing modalities and limitations. Recommendations for managing newborns known to have been exposed intrapartum to HSV are based on expert opinion because a randomized trial to compare management options is not feasible. Guidance is provided for the empirical management of infants with suspected clinical sepsis, including those who do not respond to antibacterial therapy. The present statement replaces a 2006 position statement by the Canadian Paediatric Society. PMID:24855418

  13. Systemic fungal infections in patients with human inmunodeficiency virus.

    PubMed

    Rodríguez-Cerdeira, C; Arenas, R; Moreno-Coutiño, G; Vásquez, E; Fernández, R; Chang, P

    2014-01-01

    Histoplasmosis is a systemic infection caused by the dimorphic fungus Histoplasma capsulatum. In immunocompromised patients, primary pulmonary infection can spread to the skin and meninges. Clinical manifestations appear in patients with a CD4(+) lymphocyte count of less than 150 cells/μL. Coccidioidomycosis is a systemic mycosis caused by Coccidioides immitis and Coccidioides posadasii. It can present as diffuse pulmonary disease or as a disseminated form primarily affecting the central nervous system, the bones, and the skin. Cryptococcosis is caused by Cryptococcus neoformans (var. neoformans and var. grubii) and Cryptococcus gattii, which are members of the Cryptococcus species complex and have 5 serotypes: A, B, C, D, and AD. It is a common opportunistic infection in patients with human immunodeficiency virus (HIV)/AIDS, even those receiving antiretroviral therapy. Histopathologic examination and culture of samples from any suspicious lesions are essential for the correct diagnosis of systemic fungal infections in patients with HIV/AIDS. PMID:23107866

  14. 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

  15. 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

  16. Immunopathogenesis of Oropharyngeal Candidiasis in Human Immunodeficiency Virus Infection

    PubMed Central

    de Repentigny, Louis; Lewandowski, Daniel; Jolicoeur, Paul

    2004-01-01

    Oropharyngeal and esophageal candidiases remain significant causes of morbidity in human immunodeficiency virus (HIV)-infected patients, despite the dramatic ability of antiretroviral therapy to reconstitute immunity. Notable advances have been achieved in understanding, at the molecular level, the relationships between the progression of HIV infection, the acquisition, maintenance, and clonality of oral candidal populations, and the emergence of antifungal resistance. However, the critical immunological defects which are responsible for the onset and maintenance of mucosal candidiasis in patients with HIV infection have not been elucidated. The devastating impact of HIV infection on mucosal Langerhans' cell and CD4+ cell populations is most probably central to the pathogenesis of mucosal candidiasis in HIV-infected patients. However, these defects may be partly compensated by preserved host defense mechanisms (calprotectin, keratinocytes, CD8+ T cells, and phagocytes) which, individually or together, may limit Candida albicans proliferation to the superficial mucosa. The availability of CD4C/HIV transgenic mice expressing HIV-1 in immune cells has provided the opportunity to devise a novel model of mucosal candidiasis that closely mimics the clinical and pathological features of candidal infection in human HIV infection. These transgenic mice allow, for the first time, a precise cause-and-effect analysis of the immunopathogenesis of mucosal candidiasis in HIV infection under controlled conditions in a small laboratory animal. PMID:15489345

  17. 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

  18. 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

  19. 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

  20. Molecular Mechanisms Underlying Occult Hepatitis B Virus Infection

    PubMed Central

    Samal, Jasmine; Kandpal, Manish

    2012-01-01

    Summary: Chronic hepatitis B virus (HBV) infection is a complex clinical entity frequently associated with cirrhosis and hepatocellular carcinoma (HCC). The persistence of HBV genomes in the absence of detectable surface antigenemia is termed occult HBV infection. Mutations in the surface gene rendering HBsAg undetectable by commercial assays and inhibition of HBV by suppression of viral replication and viral proteins represent two fundamentally different mechanisms that lead to occult HBV infections. The molecular mechanisms underlying occult HBV infections, including recently identified mechanisms associated with the suppression of HBV replication and inhibition of HBV proteins, are reviewed in detail. The availability of highly sensitive molecular methods has led to increased detection of occult HBV infections in various clinical settings. The clinical relevance of occult HBV infection and the utility of appropriate diagnostic methods to detect occult HBV infection are discussed. The need for specific guidelines on the diagnosis and management of occult HBV infection is being increasingly recognized; the aspects of mechanistic studies that warrant further investigation are discussed in the final section. PMID:22232374

  1. Immunopathogenesis of oropharyngeal candidiasis in human immunodeficiency virus infection.

    PubMed

    de Repentigny, Louis; Lewandowski, Daniel; Jolicoeur, Paul

    2004-10-01

    Oropharyngeal and esophageal candidiases remain significant causes of morbidity in human immunodeficiency virus (HIV)-infected patients, despite the dramatic ability of antiretroviral therapy to reconstitute immunity. Notable advances have been achieved in understanding, at the molecular level, the relationships between the progression of HIV infection, the acquisition, maintenance, and clonality of oral candidal populations, and the emergence of antifungal resistance. However, the critical immunological defects which are responsible for the onset and maintenance of mucosal candidiasis in patients with HIV infection have not been elucidated. The devastating impact of HIV infection on mucosal Langerhans' cell and CD4(+) cell populations is most probably central to the pathogenesis of mucosal candidiasis in HIV-infected patients. However, these defects may be partly compensated by preserved host defense mechanisms (calprotectin, keratinocytes, CD8(+) T cells, and phagocytes) which, individually or together, may limit Candida albicans proliferation to the superficial mucosa. The availability of CD4C/HIV transgenic mice expressing HIV-1 in immune cells has provided the opportunity to devise a novel model of mucosal candidiasis that closely mimics the clinical and pathological features of candidal infection in human HIV infection. These transgenic mice allow, for the first time, a precise cause-and-effect analysis of the immunopathogenesis of mucosal candidiasis in HIV infection under controlled conditions in a small laboratory animal. PMID:15489345

  2. Th17 lymphocytes in respiratory syncytial virus infection.

    PubMed

    Bystrom, Jonas; Al-Adhoubi, Nasra; Al-Bogami, Mohammed; Jawad, Ali S; Mageed, Rizgar A

    2013-03-01

    Infection by respiratory syncytial virus (RSV) affects approximately 33 million infants annually worldwide and is a major cause of hospitalizations. Helper T lymphocytes (Th) play a central role in the immune response during such infections. However, Th lymphocytes that produce interleukin 17 (IL-17), known as Th17 lymphocytes, in addition to been protective can also cause pathology that accompany this type of infection. The protective effects of Th17 is associated with better prognosis in most infected individuals but heightened Th17 responses causes inflammation and pathology in others. Studies employing animal models haves shown that activated Th17 lymphocytes recruit neutrophils and facilitate tertiary lymphoid structure development in infected lungs. However, IL-17 also inhibits the ability of CD8+ lymphocytes to clear viral particles and acts synergistically with the innate immune system to exacerbate inflammation. Furthermore, IL-17 enhances IL-13 production which, in turn, promotes the activation of Th2 lymphocytes and excessive mucus production. Studies of these animal models have also shown that a lack of, or inadequate, responses by the Th1 subset of T lymphocytes enhances Th17-mediated responses and that this is detrimental during RSV co-infection in experimental asthma. The available evidence, therefore, indicates that Th17 can play contradictory roles during RSV infections. The factors that determine the shift in the balance between beneficial and adverse Th17 mediated effects during RSV infection remains to be determined. PMID:23462708

  3. Tomato bushy stunt virus (TBSV) infecting Lycopersicon esculentum.

    PubMed

    Hafez, El Sayed E; Saber, Ghada A; Fattouh, Faiza A

    2010-01-01

    Tomato bushy stunt virus (TBSV) was detected in tomato crop (Lycopersicon esculentum) in Egypt with characteristic mosaic leaf deformation, stunting, and bushy growth symptoms. TBSV infection was confirmed serologically by ELISA and calculated incidence was 25.5%. Basic physicochemical properties of a purified TBSV Egh isolate were identical to known properties of tombusviruses of isometric 30-nm diameter particles, 41-kDa coat protein and the genome of approximately 4800 nt. This is the first TBSV isolate reported in Egypt. Cloning and partial sequencing of the isolate showed that it is more closely related to TBSV-P and TBSV-Ch than TBSV-Nf and TBSV-S strains of the virus. However, it is distinct from the above strains and could be a new strain of the virus which further confirms the genetic diversity of tombusviruses. PMID:21138066

  4. 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

  5. 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

  6. 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

  7. Genetic variation of occult hepatitis B virus infection.

    PubMed

    Zhu, Hui-Lan; Li, Xu; Li, Jun; Zhang, Zhen-Hua

    2016-04-01

    Occult hepatitis B virus infection (OBI), characterized as the persistence of hepatitis B virus (HBV) surface antigen (HBsAg) seronegativity and low viral load in blood or liver, is a special form of HBV infection. OBI may be related mainly to mutations in the HBV genome, although the underlying mechanism of it remains to be clarified. Mutations especially within the immunodominant "α" determinant of S protein are "hot spots" that could contribute to the occurrence of OBI via affecting antigenicity and immunogenicity of HBsAg or replication and secretion of virion. Clinical reports account for a large proportion of previous studies on OBI, while functional analyses, especially those based on full-length HBV genome, are rare. PMID:27053845

  8. Genetic variation of occult hepatitis B virus infection

    PubMed Central

    Zhu, Hui-Lan; Li, Xu; Li, Jun; Zhang, Zhen-Hua

    2016-01-01

    Occult hepatitis B virus infection (OBI), characterized as the persistence of hepatitis B virus (HBV) surface antigen (HBsAg) seronegativity and low viral load in blood or liver, is a special form of HBV infection. OBI may be related mainly to mutations in the HBV genome, although the underlying mechanism of it remains to be clarified. Mutations especially within the immunodominant “α” determinant of S protein are “hot spots” that could contribute to the occurrence of OBI via affecting antigenicity and immunogenicity of HBsAg or replication and secretion of virion. Clinical reports account for a large proportion of previous studies on OBI, while functional analyses, especially those based on full-length HBV genome, are rare. PMID:27053845

  9. Human papilloma virus and oral infections: an update.

    PubMed

    Kumaraswamy, K L; Vidhya, M

    2011-01-01

    Human papilloma virus (HPV) is one of the most common virus groups affecting the skin and mucosal areas of the body in the world today. It is also a known fact that HPV causes many lesions in the oral cavity. The most common conditions induced by oral HPV infection are usually benign-like oral papillomas, oral condylomas, and focal epithelial hyperplasia. Oral HPV infection has been found to be associated with some cases of oropharyngeal cancer, but it is not the main risk factor for this kind of cancer. HPV is been proved to be the causative agent in causation of cervical cancers without doubt, but its role as a etiologic agent in causing oral cancers needs to be evaluated and studied more to come into any conclusion. We have used review papers, case reports, cohort studies, case control studies, and various internet sources published from 1960 to 2011 to prepare this review of literature. PMID:21768696

  10. 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

  11. Acute Epstein–Barr 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 Epstein–Barr 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

  12. 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

  13. 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

  14. 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

  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. 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

  17. Evidence of Apis cerana Sacbrood virus Infection in Apis mellifera.

    PubMed

    Gong, Hong-Ri; Chen, Xiu-Xian; Chen, Yan Ping; Hu, Fu-Liang; Zhang, Jiang-Lin; Lin, Zhe-Guang; Yu, Ji-Wei; Zheng, Huo-Qing

    2016-04-15

    Sacbrood virus(SBV) is one of the most destructive viruses in the Asian honeybeeApis ceranabut is much less destructive inApis mellifera In previous studies, SBV isolates infectingA. cerana(AcSBV) and SBV isolates infectingA. mellifera(AmSBV) were identified as different serotypes, suggesting a species barrier in SBV infection. In order to investigate this species isolation, we examined the presence of SBV infection in 318A. melliferacolonies and 64A. ceranacolonies, and we identified the genotypes of SBV isolates. We also performed artificial infection experiments under both laboratory and field conditions. The results showed that 38A. melliferacolonies and 37A. ceranacolonies were positive for SBV infection. Phylogenetic analysis based on RNA-dependent RNA polymerase (RdRp) gene sequences indicated thatA. ceranaisolates and mostA. melliferaisolates formed two distinct clades but two strains isolated fromA. melliferawere clustered with theA. ceranaisolates. In the artificial-infection experiments, AcSBV negative-strand RNA could be detected in both adult bees and larvae ofA. mellifera, although there were no obvious signs of the disease, demonstrating the replication of AcSBV inA. mellifera Our results suggest that AcSBV is able to infectA. melliferacolonies with low prevalence (0.63% in this study) and pathogenicity. This work will help explain the different susceptibilities ofA. ceranaandA. melliferato sacbrood disease and is potentially useful for guiding beekeeping practices. PMID:26801569

  18. 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

  19. Virus Competition for Shedding and Tumor Formation Over Time in Marek's Disease Virus Dual-infected Chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was designed to determine what effect multiple virulent Marek’s disease viruses have on each other over time during dual-infection. Serotype 1 viruses able to be differentiated were administered either simultaneously or with a short (24 hours) or long (13 days) interval. Virus frequency ...

  20. 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

  1. Epidemiology of hepatitis B virus infection in India.

    PubMed Central

    Tandon, B N; Acharya, S K; Tandon, A

    1996-01-01

    The average estimated carrier rate of hepatitis B virus (HBV) in India is 4%, with a total pool of approximately 36 million carriers. Wide variations in social, economic, and health factors in different regions may explain variations in carrier rates from one part of the country to another. Professional blood donors constitute the major high risk group for HBV infection in India, with a hepatitis B surface antigen positivity rate of 14%. Blood transfusions represent the most important route of HBV transmission among adults. However, most of India's carrier pool is established in early childhood, predominantly by horizontal spread due to crowded living conditions and poor hygiene. Acute and subacute liver failure are common complications of viral hepatitis in India and HBV is reckoned to be the aetiological agent in 42% and 45% of adult cases, respectively. HBV is reported to be responsible for 70% of cases of chronic hepatitis and 80% of cases of cirrhosis of the liver. About 60% of patients with hepatocellular carcinoma are HBV marker positive. Small numbers of patients have been reported to be infected with the pre-core mutant virus but none with the S mutant. Coinfection with hepatitis C virus or hepatitis delta virus is comparatively uncommon. In conclusion, hepatitis B is a major public health problem in India and will continue to be until appropriate nationwide vaccination programmes and other control measures are established. PMID:8786056

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

    PubMed

    Echevarría, José Manuel; Fogeda, Marta; Avellón, Ana

    2015-04-01

    The general features of the epidemiology and ecology of hepatitis E virus in Spain are already known after 20 years of investigations. Genotype 3 strains, mainly from sub-genotype 3f, circulated among swine livestock and certain wild mammals, and would be sporadically transmitted to humans through direct contact with the reservoirs or by consumption of foods derived from them. Bivalve shellfish contaminated by hepatitis E virus from sewage could also play a role in transmission. Although the interpretation of results from seroprevalence studies in low endemic settings is still controversial, antibody to hepatitis E virus displays an overall prevalence less than 10% among the population of Spain, increasing significantly with age. From the, approximately, 150 cases of acute hepatitis E recorded in the international literature, males older than 40 years, suffering a mild, locally acquired disease predominate. In addition, hepatitis E might be more frequent in the North of the country than in other regions. Although the disease does not usually have a great clinical relevance, the occasional finding of cases of fulminant hepatitis, and of ribavirin-resistant, chronic hepatitis E virus infections among the immunocompromised would recommend the surveillance of the infection by the public health authority and a better implementation of specific diagnostic procedures in clinical laboratories. PMID:24447919

  3. 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

  4. Serum immunoglobulin A response to Norwalk virus infection.

    PubMed Central

    Erdman, D D; Gary, G W; Anderson, L J

    1989-01-01

    We describe the serum immunoglobulin A (IgA) antibody response to Norwalk virus infection in human volunteers and compare it with previously described IgM and total antibody responses. Whereas specific IgA and IgM peak within 2 weeks after onset of symptoms, titers of total blocking antibody continue to rise, implying mediation by IgG antibody. PMID:2546980

  5. Lymphocytic choriomeningitis virus infection induced by percutaneous exposure.

    PubMed

    Aebischer, O; Meylan, P; Kunz, S; Lazor-Blanchet, C

    2016-03-01

    We report a case of acquired lymphocytic choriomeningitis virus (LCMV) infection due to an accidental percutaneous inoculation of LCMV at work. The injured worker developed a flu-like syndrome, followed by pericarditis and meningoencephalitis. Seroconversion was confirmed by ELISA. The patient made a complete recovery. We review measures undertaken to prevent a similar event and propose a follow-up protocol in the event of accidental LCMV exposure. PMID:26416845

  6. [Lopinavir/ritonavir in human immunodeficiency virus-infected women].

    PubMed

    Téllez, María Jesús

    2014-11-01

    There are clear sex-related biological differences between men and women. Diseases that affect the two sexes differently are studied separately. However, some diseases affect both men and women, but their incidence or outcome are clearly different. In human immunodeficiency virus infection, the potential differences in the effects of antiretroviral therapy are poorly characterized and few studies have been designed to elucidate these differences. Moreover, women are usually poorly represented in clinical trials of antiretroviral drugs. PMID:25542872

  7. Ebola virus-like particles protect from lethal Ebola virus infection.

    PubMed

    Warfield, Kelly L; Bosio, Catharine M; Welcher, Brent C; Deal, Emily M; Mohamadzadeh, Mansour; Schmaljohn, Alan; Aman, M Javad; Bavari, Sina

    2003-12-23

    The filovirus Ebola causes hemorrhagic fever with 70-80% human mortality. High case-fatality rates, as well as known aerosol infectivity, make Ebola virus a potential global health threat and possible biological warfare agent. Development of an effective vaccine for use in natural outbreaks, response to biological attack, and protection of laboratory workers is a higher national priority than ever before. Coexpression of the Ebola virus glycoprotein (GP) and matrix protein (VP40) in mammalian cells results in spontaneous production and release of virus-like particles (VLPs) that resemble the distinctively filamentous infectious virions. VLPs have been tested and found efficacious as vaccines for several viruses, including papillomavirus, HIV, parvovirus, and rotavirus. Herein, we report that Ebola VLPs (eVLPs) were immunogenic in vitro as eVLPs matured and activated mouse bone marrow-derived dendritic cells, assessed by increases in cell-surface markers CD40, CD80, CD86, and MHC class I and II and secretion of IL-6, IL-10, macrophage inflammatory protein (MIP)-1alpha, and tumor necrosis factor alpha by the dendritic cells. Further, vaccinating mice with eVLPs activated CD4+ and CD8+ T cells, as well as CD19+ B cells. After vaccination with eVLPs, mice developed high titers of Ebola virus-specific antibodies, including neutralizing antibodies. Importantly, mice vaccinated with eVLPs were 100% protected from an otherwise lethal Ebola virus inoculation. Together, our data suggest that eVLPs represent a promising vaccine candidate for protection against Ebola virus infections and a much needed tool to examine the genesis and nature of immune responses to Ebola virus. PMID:14673108

  8. Neuro-invasion of Chandipura virus mediates pathogenesis in experimentally infected mice

    PubMed Central

    Anukumar, Balakrishnan; Amirthalingam, Balasubramaniam G; Shelke, Vijay N; Gunjikar, Rashmi; Shewale, Poonam

    2013-01-01

    Neuro-tropism is a major feature in many viral infections. Chandipura virus produces neurological symptoms in naturally infected young children and experimentally infected suckling mice. This study was undertaken to find out the neuro-invasive behaviour of Chandipura virus in suckling mice. The suckling mice were infected with the virus via footpad injection. Different tissues were collected at 24-h intervals up to 96-h post infection and processed for virus quantification and histological study. Further confirming the virus predilection to nerves tissues, the adult mice were inoculated with the virus via different routes. The suckling mice experimental results revealed a progressive replication of virus in spinal cord and brain. The progressive-virus replication was not observed in the other tissues like kidney, spleen, liver etc. Histo-pathological lesions noticed in the spinal cord and brain tissues suggested the extensive damages in these tissues. In adult mice experiment, the virus replication observed only in the brain of the mice infected via intra-cerebral route. From this study, we conclude that nervous tissues are predilection sites for Chandipura virus replication in suckling and adult mice. In suckling mice, virus might transmit through nervous tissues for dissemination. In contrast, the adult mice the nervous terminal might not pick up the virus through footpad infection. The pathogenesis in mice might be due to the virus replication mediated damage in the central nervous system. PMID:23826408

  9. Cross-species infection of Deformed Wing virus poses a new threat to pollinator conservation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Here we provide the evidence that Deformed Wing Virus (DWV), one of the most prevalent and common viruses in honey bees Apis mellifera, could cause an infection in bumble bees, Bombus huntii and that the virus infection could spread over the entire body of B. huntii. Our results showed that gut of...

  10. Gene expression responses to highly pathogenic avian influenza H5N1 virus infections in ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Differences in host response to infection with avian influenza (AI) viruses were investigated by identifying genes differentially expressed in tissues of infected ducks. Clear differences in pathogenicity were observed among ducks inoculated with five H5N1 HPAI viruses. Virus titers in tissues cor...

  11. Subclinical Highly Pathogenic Avian Influenza Virus Infection among Vaccinated Chickens, China

    PubMed Central

    Ma, Qing-Xia; Jiang, Wen-Ming; Liu, Shuo; Wang, Su-Chun; Zhuang, Qing-Ye; Hou, Guang-Yu; Liu, Xiang-Ming; Sui, Zheng-Hong

    2014-01-01

    Subclinical infection of vaccinated chickens with a highly pathogenic avian influenza A(H5N2) virus was identified through routine surveillance in China. Investigation suggested that the virus has evolved into multiple genotypes. To better control transmission of the virus, we recommend a strengthened program of education, biosecurity, rapid diagnostics, surveillance, and elimination of infected poultry. PMID:25418710

  12. A dual drug regimen synergistically blocks human parainfluenza virus infection

    NASA Astrophysics Data System (ADS)

    Bailly, Benjamin; Dirr, Larissa; El-Deeb, Ibrahim M.; Altmeyer, Ralf; Guillon, Patrice; von Itzstein, Mark

    2016-04-01

    Human parainfluenza type-3 virus (hPIV-3) is one of the principal aetiological agents of acute respiratory illness in infants worldwide and also shows high disease severity in the elderly and immunocompromised, but neither therapies nor vaccines are available to treat or prevent infection, respectively. Using a multidisciplinary approach we report herein that the approved drug suramin acts as a non-competitive in vitro inhibitor of the hPIV-3 haemagglutinin-neuraminidase (HN). Furthermore, the drug inhibits viral replication in mammalian epithelial cells with an IC50 of 30 μM, when applied post-adsorption. Significantly, we show in cell-based drug-combination studies using virus infection blockade assays, that suramin acts synergistically with the anti-influenza virus drug zanamivir. Our data suggests that lower concentrations of both drugs can be used to yield high levels of inhibition. Finally, using NMR spectroscopy and in silico docking simulations we confirmed that suramin binds HN simultaneously with zanamivir. This binding event occurs most likely in the vicinity of the protein primary binding site, resulting in an enhancement of the inhibitory potential of the N-acetylneuraminic acid-based inhibitor. This study offers a potentially exciting avenue for the treatment of parainfluenza infection by a combinatorial repurposing approach of well-established approved drugs.

  13. Occult Hepatitis B Virus Infection in Chacma Baboons, South Africa

    PubMed Central

    Dickens, Caroline; Kew, Michael C.; Purcell, Robert H.

    2013-01-01

    During previous studies of susceptibility to hepatitis B virus (HBV) infection, HBV DNA was detected in 2/6 wild-caught baboons. In the present study, HBV DNA was amplified from 15/69 wild-caught baboons. All animals were negative for HBV surface antigen and antibody against HBV core antigen. Liver tissue from 1 baboon was immunohistochemically negative for HBV surface antigen but positive for HBV core antigen. The complete HBV genome of an isolate from this liver clustered with subgenotype A2. Reverse transcription PCR of liver RNA amplified virus precore and surface protein genes, indicating replication of virus in baboon liver tissue. Four experimentally naive baboons were injected with serum from HBV DNA–positive baboons. These 4 baboons showed transient seroconversion, and HBV DNA was amplified from serum at various times after infection. The presence of HBV DNA at relatively low levels and in the absence of serologic markers in the baboon, a nonhuman primate, indicates an occult infection. PMID:23631817

  14. A dual drug regimen synergistically blocks human parainfluenza virus infection

    PubMed Central

    Bailly, Benjamin; Dirr, Larissa; El-Deeb, Ibrahim M.; Altmeyer, Ralf; Guillon, Patrice; von Itzstein, Mark

    2016-01-01

    Human parainfluenza type-3 virus (hPIV-3) is one of the principal aetiological agents of acute respiratory illness in infants worldwide and also shows high disease severity in the elderly and immunocompromised, but neither therapies nor vaccines are available to treat or prevent infection, respectively. Using a multidisciplinary approach we report herein that the approved drug suramin acts as a non-competitive in vitro inhibitor of the hPIV-3 haemagglutinin-neuraminidase (HN). Furthermore, the drug inhibits viral replication in mammalian epithelial cells with an IC50 of 30 μM, when applied post-adsorption. Significantly, we show in cell-based drug-combination studies using virus infection blockade assays, that suramin acts synergistically with the anti-influenza virus drug zanamivir. Our data suggests that lower concentrations of both drugs can be used to yield high levels of inhibition. Finally, using NMR spectroscopy and in silico docking simulations we confirmed that suramin binds HN simultaneously with zanamivir. This binding event occurs most likely in the vicinity of the protein primary binding site, resulting in an enhancement of the inhibitory potential of the N-acetylneuraminic acid-based inhibitor. This study offers a potentially exciting avenue for the treatment of parainfluenza infection by a combinatorial repurposing approach of well-established approved drugs. PMID:27053240

  15. A dual drug regimen synergistically blocks human parainfluenza virus infection.

    PubMed

    Bailly, Benjamin; Dirr, Larissa; El-Deeb, Ibrahim M; Altmeyer, Ralf; Guillon, Patrice; von Itzstein, Mark

    2016-01-01

    Human parainfluenza type-3 virus (hPIV-3) is one of the principal aetiological agents of acute respiratory illness in infants worldwide and also shows high disease severity in the elderly and immunocompromised, but neither therapies nor vaccines are available to treat or prevent infection, respectively. Using a multidisciplinary approach we report herein that the approved drug suramin acts as a non-competitive in vitro inhibitor of the hPIV-3 haemagglutinin-neuraminidase (HN). Furthermore, the drug inhibits viral replication in mammalian epithelial cells with an IC50 of 30 μM, when applied post-adsorption. Significantly, we show in cell-based drug-combination studies using virus infection blockade assays, that suramin acts synergistically with the anti-influenza virus drug zanamivir. Our data suggests that lower concentrations of both drugs can be used to yield high levels of inhibition. Finally, using NMR spectroscopy and in silico docking simulations we confirmed that suramin binds HN simultaneously with zanamivir. This binding event occurs most likely in the vicinity of the protein primary binding site, resulting in an enhancement of the inhibitory potential of the N-acetylneuraminic acid-based inhibitor. This study offers a potentially exciting avenue for the treatment of parainfluenza infection by a combinatorial repurposing approach of well-established approved drugs. PMID:27053240

  16. Hepatitis B Virus Infection and Immunizations among Asian American College Students: Infection, Exposure, and Immunity Rates

    ERIC Educational Resources Information Center

    Lee, Haeok; Kiang, Peter; Watanabe, Paul; Halon, Patricia; Shi, Ling; Church, Daniel R.

    2013-01-01

    Objectives: To evaluate the prevalence of hepatitis B virus (HBV) infection, exposure, and immunity among Asian American college students as a basis for evaluating HBV screening and vaccination policy. Participants and Methods: Self-identified Asian American college students aged 18years or older were examined. Serological tests of HBV surface

  17. Hepatitis B Virus Infection and Immunizations among Asian American College Students: Infection, Exposure, and Immunity Rates

    ERIC Educational Resources Information Center

    Lee, Haeok; Kiang, Peter; Watanabe, Paul; Halon, Patricia; Shi, Ling; Church, Daniel R.

    2013-01-01

    Objectives: To evaluate the prevalence of hepatitis B virus (HBV) infection, exposure, and immunity among Asian American college students as a basis for evaluating HBV screening and vaccination policy. Participants and Methods: Self-identified Asian American college students aged 18 years or older were examined. Serological tests of HBV surface…

  18. Medical management of human immunodeficiency virus infection

    PubMed Central

    2008-01-01

    The human immunodeficiency virus (HIV)/ acquired immune deficiency syndrome (AIDS) pandemic has pervasive effects on culture, economics, policy, and human development. All organs can be affected by complications of HIV/AIDS, including the eye. When sufficient resources are available and widespread antiretroviral resistance does not exist, the four available classes of antiretroviral agents - nucleoside/ nucleotide reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, protease inhibitors, and fusion inhibitors - can be combined to provide highly active antiretroviral therapy (HAART). For many (not all) patients, HAART converts an inexorably fatal disease into a chronic disease with a fairly good prognosis. Use of HAART often induces partial immune recovery, which has predominantly beneficial effects on ocular complications of AIDS. However, HAART-induced immune recovery sometimes results in immune recovery inflammatory syndromes, such as immune recovery uveitis. Use of HAART is the single most useful intervention for most patients with ocular complications of AIDS. However, specific ocular therapy is also critical to avoid blindness in the early months before immune recovery can occur, or if HAART is unavailable. Increasing availability of HAART worldwide shows great promise to alleviate one of the world′s greatest plagues. However, predictable secular trends in the AIDS epidemic make it likely that the number of cases of ocular complications of AIDS will increase substantially before they decrease. Ophthalmologists worldwide should be familiar with the diagnosis and management of cytomegalovirus retinitis - the most common ocular complication of AIDS - and should establish partnerships with physicians who are able to provide HAART. Research is needed to determine the optimal approach for managing cytomegalovirus retinitis in resource- constrained settings. PMID:18711266

  19. Human Immunodeficiency Virus Infection and Host Defense in the Lungs.

    PubMed

    Charles, Tysheena P; Shellito, Judd E

    2016-04-01

    Immunosuppression associated with human immunodeficiency virus (HIV) infection impacts all components of host defense against pulmonary infection. Cells within the lung have altered immune function and are important reservoirs for HIV infection. The host immune response to infected lung cells further compromises responses to a secondary pathogenic insult. In the upper respiratory tract, mucociliary function is impaired and there are decreased levels of salivary immunoglobulin A. Host defenses in the lower respiratory tract are controlled by alveolar macrophages, lymphocytes, and polymorphonuclear leukocytes. As HIV infection progresses, lung CD4 T cells are reduced in number causing a lack of activation signals from CD4 T cells and impaired defense by macrophages. CD8 T cells, on the other hand, are increased in number and cause lymphocytic alveolitis. Specific antibody responses by B-lymphocytes are decreased and opsonization of microorganisms is impaired. These observed defects in host defense of the respiratory tract explain the susceptibility of HIV-infected persons for oropharyngeal candidiasis, bacterial pneumonia, Pneumocystis pneumonia, and other opportunistic infections. PMID:26974294

  20. Chronic hepatitis C virus infection, a new cardiovascular risk factor?

    PubMed

    Domont, Fanny; Cacoub, Patrice

    2016-05-01

    Among the large scope of extrahepatic manifestations related to hepatitis C virus (HCV) infection, many studies recently evaluated the frequency and characteristics of cardiovascular involvement. To assess the current published data on HCV infection and cardiovascular diseases. Published studies on cardiovascular disease, i.e. cerebrovascular accident and ischaemic heart disease in subjects with HCV infection were analysed from literature databases. Subjects with HCV chronic infection have an increased prevalence of carotid atherosclerosis and increased intima-media thickness compared to healthy controls or those with hepatitis B or non-alcoholic steatohepatitis. Active chronic HCV infection appears as an independent risk factor for ischaemic cerebrovascular accidents. Active chronic HCV infection is associated with increased risk of ischaemic heart disease. In some studies, successful interferon-based therapy showed a beneficial impact on the cardiovascular risk. The risk of major cardiovascular events is higher in patients with HCV infection compared to controls, independent of the severity of the liver disease or the common cardiovascular risk factors. The beneficial impact of interferon-based therapy needs to be confirmed with new direct antiviral interferon-free agents in prospective studies with extended follow-up. PMID:26763484