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Sample records for pathogenic virus infection

  1. Highly pathogenic fowlpox virus in cutaneously infected chickens, China.

    PubMed

    Zhao, Kui; He, Wenqi; Xie, Shengnan; Song, Deguang; Lu, Huijun; Pan, Wei; Zhou, Ping; Liu, Wenfeng; Lu, Rongguang; Zhou, Jiyong; Gao, Feng

    2014-07-01

    We investigated an acute outbreak of the cutaneous form of fowlpox among chickens in China in November 2009. Using pathologic and virologic methods, we identified a novel type of fowlpox virus that carried an integrated genomic sequence of reticuloendotheliosis virus. This highly pathogenic virus could lead to severe ecologic effects and economic losses. PMID:24963887

  2. 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...

  3. High doses of highly pathogenic avian influenza virus in chicken meat are required to infect ferrets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    H5N1 high pathogenicity avian influenza viruses (HPAIV) have caused natural and experimental infections in various animals through consumption of infected bird carcasses and meat. However, little is known about the quantity of virus required and if all HPAIV subtypes can cause infections following c...

  4. 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 ...

  5. Age at infection affects the pathogenicity of Asian highly pathogenic avian influenza H5N1 viruses in ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Asian H5N1 avian influenza (AI) viruses have changed from producing no disease or mild respiratory infections in ducks to some strains causing systemic disease and death. Differences in pathogenicity between four of these viruses as well as the effect of host age on the outcome of infection were...

  6. Pathogenic simian immunodeficiency virus infection is associated with expansion of the enteric virome

    PubMed Central

    Handley, Scott; Thackray, Larissa B.; Zhao, Guoyan; Presti, Rachel; Miller, Andrew; Droit, Lindsay; Abbink, Peter; Maxfield, Lori F.; Kambal, Amal; Duan, Erning; Stanley, Kelly; Kramer, Joshua; Macri, Sheila C.; Permar, Sallie R.; Schmitz, Joern E.; Mansfield, Keith; Brenchley, Jason M.; Veazey, Ronald S.; Stappenbeck, Thaddeus S.; Wang, David; Barouch, Dan H.; Virgin, Herbert W.

    2012-01-01

    SUMMARY Pathogenic simian immunodeficiency virus (SIV) infection is associated with enteropathy which likely contributes to AIDS progression. To identify candidate etiologies for AIDS enteropathy, we used next generation sequencing to define the enteric virome during SIV infection in nonhuman primates. Pathogenic, but not non-pathogenic, SIV infection was associated with significant expansion of the enteric virome. We identified at least 32 previously undescribed enteric viruses during pathogenic SIV infection and confirmed their presence using viral culture and PCR testing. We detected unsuspected mucosal adenovirus infection associated with enteritis as well as parvovirus viremia in animals with advanced AIDS, indicating the pathogenic potential of SIV-associated expansion of the enteric virome. No association between pathogenic SIV infection and the family-level taxonomy of enteric bacteria was detected. Thus, enteric viral infections may contribute to AIDS enteropathy and disease progression. These findings underline the importance of metagenomic analysis of the virome for understanding AIDS pathogenesis. PMID:23063120

  7. Simian Immunodeficiency Virus Infection of Chimpanzees (Pan troglodytes) Shares Features of Both Pathogenic and Non-pathogenic Lentiviral Infections

    PubMed Central

    Greenwood, Edward J. D.; Schmidt, Fabian; Kondova, Ivanela; Niphuis, Henk; Hodara, Vida L.; Clissold, Leah; McLay, Kirsten; Guerra, Bernadette; Redrobe, Sharon; Giavedoni, Luis D.; Lanford, Robert E.; Murthy, Krishna K.; Rouet, François; Heeney, Jonathan L.

    2015-01-01

    The virus-host relationship in simian immunodeficiency virus (SIV) infected chimpanzees is thought to be different from that found in other SIV infected African primates. However, studies of captive SIVcpz infected chimpanzees are limited. Previously, the natural SIVcpz infection of one chimpanzee, and the experimental infection of six chimpanzees was reported, with limited follow-up. Here, we present a long-term study of these seven animals, with a retrospective re-examination of the early stages of infection. The only clinical signs consistent with AIDS or AIDS associated disease was thrombocytopenia in two cases, associated with the development of anti-platelet antibodies. However, compared to uninfected and HIV-1 infected animals, SIVcpz infected animals had significantly lower levels of peripheral blood CD4+ T-cells. Despite this, levels of T-cell activation in chronic infection were not significantly elevated. In addition, while plasma levels of β2 microglobulin, neopterin and soluble TNF-related apoptosis inducing ligand (sTRAIL) were elevated in acute infection, these markers returned to near-normal levels in chronic infection, reminiscent of immune activation patterns in ‘natural host’ species. Furthermore, plasma soluble CD14 was not elevated in chronic infection. However, examination of the secondary lymphoid environment revealed persistent changes to the lymphoid structure, including follicular hyperplasia in SIVcpz infected animals. In addition, both SIV and HIV-1 infected chimpanzees showed increased levels of deposition of collagen and increased levels of Mx1 expression in the T-cell zones of the lymph node. The outcome of SIVcpz infection of captive chimpanzees therefore shares features of both non-pathogenic and pathogenic lentivirus infections. PMID:26360709

  8. Highly pathogenic avian influenza virus (H5N1) in experimentally infected adult mute swans.

    PubMed

    Kalthoff, Donata; Breithaupt, Angele; Teifke, Jens P; Globig, Anja; Harder, Timm; Mettenleiter, Thomas C; Beer, Martin

    2008-08-01

    Adult, healthy mute swans were experimentally infected with highly pathogenic avian influenza virus A/Cygnus cygnus/Germany/R65/2006 subtype H5N1. Immunologically naive birds died, whereas animals with preexisting, naturally acquired avian influenza virus-specific antibodies became infected asymptomatically and shed virus. Adult mute swans are highly susceptible, excrete virus, and can be clinically protected by preexposure immunity. PMID:18680652

  9. Human Infection with Highly Pathogenic A(H7N7) Avian Influenza Virus, Italy, 2013

    PubMed Central

    Rossini, Giada; Facchini, Marzia; Vaccari, Gabriele; Di Trani, Livia; Di Martino, Angela; Gaibani, Paolo; Vocale, Caterina; Cattoli, Giovanni; Bennett, Michael; McCauley, John W.; Rezza, Giovanni; Moro, Maria Luisa; Rangoni, Roberto; Finarelli, Alba Carola; Landini, Maria Paola; Castrucci, Maria Rita; Donatelli, Isabella

    2014-01-01

    During an influenza A(H7N7) virus outbreak among poultry in Italy during August–September 2013, infection with a highly pathogenic A(H7N7) avian influenza virus was diagnosed for 3 poultry workers with conjunctivitis. Genetic analyses revealed that the viruses from the humans were closely related to those from chickens on affected farms. PMID:25271444

  10. Highly Pathogenic Avian Influenza Virus Infection of Mallards with Homo- and Heterosubtypic Immunity Induced by Low Pathogenic Avian Influenza Viruses

    PubMed Central

    Fereidouni, Sasan R.; Starick, Elke; Beer, Martin; Wilking, Hendrik; Kalthoff, Donata; Grund, Christian; Häuslaigner, Rafaela; Breithaupt, Angele; Lange, Elke; Harder, Timm C.

    2009-01-01

    The potential role of wild birds as carriers of highly pathogenic avian influenza virus (HPAIV) subtype H5N1 is still a matter of debate. Consecutive or simultaneous infections with different subtypes of influenza viruses of low pathogenicity (LPAIV) are very common in wild duck populations. To better understand the epidemiology and pathogenesis of HPAIV H5N1 infections in natural ecosystems, we investigated the influence of prior infection of mallards with homo- (H5N2) and heterosubtypic (H4N6) LPAIV on exposure to HPAIV H5N1. In mallards with homosubtypic immunity induced by LPAIV infection, clinical disease was absent and shedding of HPAIV from respiratory and intestinal tracts was grossly reduced compared to the heterosubtypic and control groups (mean GEC/100 µl at 3 dpi: 3.0×102 vs. 2.3×104 vs. 8.7×104; p<0.05). Heterosubtypic immunity induced by an H4N6 infection mediated a similar but less pronounced effect. We conclude that the epidemiology of HPAIV H5N1 in mallards and probably other aquatic wild bird species is massively influenced by interfering immunity induced by prior homo- and heterosubtypic LPAIV infections. PMID:19693268

  11. 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

  12. Within-Host Models of High and Low Pathogenic Influenza Virus Infections: The Role of Macrophages.

    PubMed

    Pawelek, Kasia A; Dor, Daniel; Salmeron, Cristian; Handel, Andreas

    2016-01-01

    The World Health Organization identifies influenza as a major public health problem. While the strains commonly circulating in humans usually do not cause severe pathogenicity in healthy adults, some strains that have infected humans, such as H5N1, can cause high morbidity and mortality. Based on the severity of the disease, influenza viruses are sometimes categorized as either being highly pathogenic (HP) or having low pathogenicity (LP). The reasons why some strains are LP and others HP are not fully understood. While there are likely multiple mechanisms of interaction between the virus and the immune response that determine LP versus HP outcomes, we focus here on one component, namely macrophages (MP). There is some evidence that MP may both help fight the infection and become productively infected with HP influenza viruses. We developed mathematical models for influenza infections which explicitly included the dynamics and action of MP. We fit these models to viral load and macrophage count data from experimental infections of mice with LP and HP strains. Our results suggest that MP may not only help fight an influenza infection but may contribute to virus production in infections with HP viruses. We also explored the impact of combination therapies with antivirals and anti-inflammatory drugs on HP infections. Our study suggests a possible mechanism of MP in determining HP versus LP outcomes, and how different interventions might affect infection dynamics. PMID:26918620

  13. Within-Host Models of High and Low Pathogenic Influenza Virus Infections: The Role of Macrophages

    PubMed Central

    Pawelek, Kasia A.; Dor, Daniel; Salmeron, Cristian; Handel, Andreas

    2016-01-01

    The World Health Organization identifies influenza as a major public health problem. While the strains commonly circulating in humans usually do not cause severe pathogenicity in healthy adults, some strains that have infected humans, such as H5N1, can cause high morbidity and mortality. Based on the severity of the disease, influenza viruses are sometimes categorized as either being highly pathogenic (HP) or having low pathogenicity (LP). The reasons why some strains are LP and others HP are not fully understood. While there are likely multiple mechanisms of interaction between the virus and the immune response that determine LP versus HP outcomes, we focus here on one component, namely macrophages (MP). There is some evidence that MP may both help fight the infection and become productively infected with HP influenza viruses. We developed mathematical models for influenza infections which explicitly included the dynamics and action of MP. We fit these models to viral load and macrophage count data from experimental infections of mice with LP and HP strains. Our results suggest that MP may not only help fight an influenza infection but may contribute to virus production in infections with HP viruses. We also explored the impact of combination therapies with antivirals and anti-inflammatory drugs on HP infections. Our study suggests a possible mechanism of MP in determining HP versus LP outcomes, and how different interventions might affect infection dynamics. PMID:26918620

  14. Serum and egg yolk antibody detection in chickens infected with low pathogenicity avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Surveillance for low pathogenicity avian influenza virus (LPAIV) infections has primarily relied on labor intensive collection and serological testing of serum, but for many poultry diseases, easier to collect yolk samples have replaced serum for surveillance testing. A time course LPAIV infection s...

  15. Infection of Myofibers Contributes to Increased Pathogenicity during Infection with an Epidemic Strain of Chikungunya Virus

    PubMed Central

    Rohatgi, Anjali; Corbo, Joseph C.; Monte, Kristen; Higgs, Stephen; Vanlandingham, Dana L.; Kardon, Gabrielle

    2014-01-01

    ABSTRACT Chikungunya virus (CHIKV) is an alphavirus transmitted by mosquitoes that is known to cause severe arthritis and myositis in affected patients. The ongoing epidemic began in eastern Africa in 2004 and then spread to islands of the Indian Ocean, India, and Southeast Asia, ultimately afflicting millions. During this outbreak, more severe disease manifestations, including fatalities, have been documented. The reasons for this change in pathogenesis are multifactorial but likely include mutations that have arisen in the viral genome which could alter disease pathogenesis. To test this hypothesis, we used a murine model of CHIKV to compare the disease pathogeneses of two recombinant strains of CHIKV, the first derived from the La Reunion outbreak in 2006 (LR2006 OPY1) and the second isolated from Senegal in 1983 (37997). While the two strains exhibited similar growth in mammalian cells in vitro, we observed more severe clinical disease and pathology in mice infected with the LR2006 OPY1 strain of CHIKV, which included prolonged viremia and elevated viral titers and persistence in the muscle, resulting in devastating myonecrosis. Both CHIKV strains infected connective tissue fibroblasts of the muscle, but only the LR2006 OPY1 strain replicated within myofibers in vivo, despite similar growth of the two strains in these cell types in vitro. However, when the 37997 strain was administered directly into muscle, myofiber infection was comparable to that in LR2006 OPY1-infected mice. These results indicate that differences in the ability of the strain of CHIKV to establish infection in myofibers may contribute to the increased disease severity. IMPORTANCE CHIKV is an emerging pathogen that causes significant morbidity. Little is known about the pathogenesis of the disease, and this study suggests that the ability of a recent epidemic strain to infect myofibers results in increased disease severity. Better understanding of how CHIKV causes disease contributes to the

  16. 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...

  17. Virus interference between H7N2 low pathogenic avian influenza virus and lentogenic Newcastle disease virus in experimental co-infections in chickens and turkeys

    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. Exposure to lentogenic NDV, either from live vaccines or field strains, is nearly unavoidable for poultry, and co-infections with low pathogenic (LP) AIV are expected to ...

  18. Transcriptome Analysis of Bombyx mori Larval Midgut during Persistent and Pathogenic Cytoplasmic Polyhedrosis Virus Infection

    PubMed Central

    Kolliopoulou, Anna; Van Nieuwerburgh, Filip; Stravopodis, Dimitrios J.; Deforce, Dieter; Swevers, Luc; Smagghe, Guy

    2015-01-01

    Many insects can be persistently infected with viruses but do not show any obvious adverse effects with respect to physiology, development or reproduction. Here, Bombyx mori strain Daizo, persistently infected with cytoplasmic polyhedrosis virus (BmCPV), was used to study the host’s transcriptional response after pathogenic infection with the same virus in midgut tissue of larvae persistently and pathogenically infected as 2nd and 4th instars. Next generation sequencing revealed that from 13,769 expressed genes, 167 were upregulated and 141 downregulated in both larval instars following pathogenic infection. Several genes that could possibly be involved in B. mori immune response against BmCPV or that may be induced by the virus in order to increase infectivity were identified, whereas classification of differentially expressed transcripts (confirmed by qRT-PCR) resulted in gene categories related to physical barriers, immune responses, proteolytic / metabolic enzymes, heat-shock proteins, hormonal signaling and uncharacterized proteins. Comparison of our data with the available literature (pathogenic infection of persistently vs. non-persistently infected larvae) unveiled various similarities of response in both cases, which suggests that pre-existing persistent infection does not affect in a major way the transcriptome response against pathogenic infection. To investigate the possible host’s RNAi response against BmCPV challenge, the differential expression of RNAi-related genes and the accumulation of viral small RNAs (vsRNAs) were studied. During pathogenic infection, siRNA-like traces like the 2-fold up-regulation of the core RNAi genes Ago-2 and Dcr-2 as well as a peak of 20 nt small RNAs were observed. Interestingly, vsRNAs of the same size were detected at lower rates in persistently infected larvae. Collectively, our data provide an initial assessment of the relative significance of persistent infection of silkworm larvae on the host response following

  19. Immediate early responses of avian tracheal epithelial cells to infection with highly pathogenic avian invluenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Highly pathogenic (HP) avian influenza viruses (AIV) present an ongoing threat to the world poultry industry. In order to develop new AIV control strategies it is necessary to understand the underlying mechanism of viral infection at mucosal respiratory sites. Chicken and duck tracheal epithelial ...

  20. Synergistic pathogenic effects of co-infection of subgroup J avian leukosis virus and reticuloendotheliosis virus in broiler chickens.

    PubMed

    Dong, Xuan; Zhao, Peng; Chang, Shuang; Ju, Sidi; Li, Yang; Meng, Fanfeng; Sun, Peng; Cui, Zhizhong

    2015-01-01

    To study interactions between avian leukosis virus subgroup J (ALV-J) and reticuloendotheliosis virus (REV) and the effects of co-infection on pathogenicity of these viruses, 1-day-old broiler chicks were infected with ALV-J, REV or both ALV-J and REV. The results indicated that co-infection of ALV-J and REV induced more growth retardation and higher mortality rate than ALV-J or REV single infection (P < 0.05). Chickens co-infected with ALV-J and REV also showed more severe immunosuppression than those with a single infection. This was manifested by significantly lower bursa of Fabricius and thymus to body weight ratios and lower antibody responses to Newcastle disease virus and H9-avian influenza virus (P < 0.05). Perihepatitis and pericarditis related to severe infection with Escherichia coli were found in many of the dead birds. E. coli was isolated from each case of perihepatitis and pericarditis. The mortality associated with E. coli infection in the co-infection groups was significantly higher than in the other groups (P < 0.05). Among 516 tested E. coli isolates from 58 dead birds, 12 serotypes of the O-antigen were identified in two experiments. Different serotypes of E. coli strains were even isolated from the same organ of the same bird. Diversification of O-serotypes suggested that perihepatitis and pericarditis associated with E. coli infection was the most frequent secondary infection following the immunosuppression induced by ALV-J and REV co-infection. These results suggested that the co-infection of ALV-J and REV caused more serious synergistic pathogenic effects, growth retardation, immunosuppression, and secondary E. coli infection in broiler chickens. PMID:25484188

  1. Variation in infectivity and adaptation of wild duck- and poultry-origin high pathogenicity and low pathogenicity avian influenza viruses for poultry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza (AI) viruses vary in their adaptation which impacts transmission between and infection of different bird species. We determine the intranasal mean bird infectious doses (BID50) for 11 high pathogenicity (HP) AI viruses for layer type chickens (LC), and three low pathogenicity (LP) A...

  2. Pathogenicity of different rabies virus variants inversely correlates with apoptosis and rabies virus glycoprotein expression in infected primary neuron cultures.

    PubMed

    Morimoto, K; Hooper, D C; Spitsin, S; Koprowski, H; Dietzschold, B

    1999-01-01

    The mouse-adapted rabies virus strain CVS-24 has stable variants, CVS-B2c and CVS-N2c, which differ greatly in their pathogenicity for normal adult mice and in their ability to infect nonneuronal cells. The glycoprotein (G protein), which has previously been implicated in rabies virus pathogenicity, shows substantial structural differences between these variants. Although prior studies have identified antigenic site III of the G protein as the major pathogenicity determinant, CVS-B2c and CVS-N2c do not vary at this site. The possibility that pathogenicity is inversely related to G protein expression levels is suggested by the finding that CVS-B2c, the less pathogenic variant, expresses at least fourfold-higher levels of G protein than CVS-N2c in infected neurons. Although there is some difference between CVS-B2c- and CVS-N2c-infected neurons in G protein mRNA expression levels, the differential expression of G protein appears to be largely determined by posttranslational mechanisms that affect G protein stability. Pulse-chase experiments indicated that the G protein of CVS-B2c is degraded more slowly than that of CVS-N2c. The accumulation of G protein correlated with the induction of programmed cell death in CVS-B2c-infected neurons. The extent of apoptosis was considerably lower in CVS-N2c-infected neurons, where G protein expression was minimal. While nucleoprotein (N protein) expression levels were similar in neurons infected with either variant, the transport of N protein into neuronal processes was strongly inhibited in CVS-B2c-infected cells. Thus, downregulation of G protein expression in neuronal cells evidently contributes to rabies virus pathogenesis by preventing apoptosis and the apparently associated failure of the axonal transport of N protein. PMID:9847357

  3. Pathogenicity of Different Rabies Virus Variants Inversely Correlates with Apoptosis and Rabies Virus Glycoprotein Expression in Infected Primary Neuron Cultures

    PubMed Central

    Morimoto, Kinjiro; Hooper, D. Craig; Spitsin, Sergei; Koprowski, Hilary; Dietzschold, Bernhard

    1999-01-01

    The mouse-adapted rabies virus strain CVS-24 has stable variants, CVS-B2c and CVS-N2c, which differ greatly in their pathogenicity for normal adult mice and in their ability to infect nonneuronal cells. The glycoprotein (G protein), which has previously been implicated in rabies virus pathogenicity, shows substantial structural differences between these variants. Although prior studies have identified antigenic site III of the G protein as the major pathogenicity determinant, CVS-B2c and CVS-N2c do not vary at this site. The possibility that pathogenicity is inversely related to G protein expression levels is suggested by the finding that CVS-B2c, the less pathogenic variant, expresses at least fourfold-higher levels of G protein than CVS-N2c in infected neurons. Although there is some difference between CVS-B2c- and CVS-N2c-infected neurons in G protein mRNA expression levels, the differential expression of G protein appears to be largely determined by posttranslational mechanisms that affect G protein stability. Pulse-chase experiments indicated that the G protein of CVS-B2c is degraded more slowly than that of CVS-N2c. The accumulation of G protein correlated with the induction of programmed cell death in CVS-B2c-infected neurons. The extent of apoptosis was considerably lower in CVS-N2c-infected neurons, where G protein expression was minimal. While nucleoprotein (N protein) expression levels were similar in neurons infected with either variant, the transport of N protein into neuronal processes was strongly inhibited in CVS-B2c-infected cells. Thus, downregulation of G protein expression in neuronal cells evidently contributes to rabies virus pathogenesis by preventing apoptosis and the apparently associated failure of the axonal transport of N protein. PMID:9847357

  4. Viruses accumulate in aging infection centers of a fungal forest pathogen

    PubMed Central

    Vainio, Eeva J; Müller, Michael M; Korhonen, Kari; Piri, Tuula; Hantula, Jarkko

    2015-01-01

    Fungal viruses (mycoviruses) with RNA genomes are believed to lack extracellular infective particles. These viruses are transmitted laterally among fungal strains through mycelial anastomoses or vertically via their infected spores, but little is known regarding their prevalence and patterns of dispersal under natural conditions. Here, we examined, in detail, the spatial and temporal changes in a mycovirus community and its host fungus Heterobasidion parviporum, the most devastating fungal pathogen of conifers in the Boreal forest region. During the 7-year sampling period, viruses accumulated in clonal host individuals as a result of indigenous viruses spreading within and between clones as well as novel strains arriving via airborne spores. Viral community changes produced pockets of heterogeneity within large H. parviporum clones. The appearance of novel viral infections in aging clones indicated that transient cell-to-cell contacts between Heterobasidion strains are likely to occur more frequently than what was inferred from genotypic analyses. Intraspecific variation was low among the three partitivirus species at the study site, whereas the unassigned viral species HetRV6 was highly polymorphic. The accumulation of point mutations during persistent infections resulted in viral diversification, that is, the presence of nearly identical viral sequence variants within single clones. Our results also suggest that co-infections by distantly related viral species are more stable than those between conspecific strains, and mutual exclusion may play a role in determining mycoviral communities. PMID:25126757

  5. Pathogenicity of an Indian isolate of bovine viral diarrhea virus 1b in experimentally infected calves.

    PubMed

    Galav, V; Mishra, N; Dubey, R; Rajukumar, K; Pitale, S S; Shrivastav, A B; Pradhan, H K

    2007-12-01

    The aim of this study was to determine the pathogenicity of an Indian bovine viral diarrhea virus (BVDV) 1b isolate in 7-9-months-old male calves. Infected (four) and control (two) calves were bled at three days interval for hematological, virological and serological studies until day 27. All infected calves developed respiratory illness, biphasic pyrexia, mild diarrhea, leucopenia and mild thrombocytopenia. Viraemia was demonstrated between 3 and 15dpi and the infected calves seroconverted by 15dpi. Prominent kidney lesions were endothelial cell swelling, proliferation of mesangial cells and podocytes leading to glomerular space obliteration. Degeneration and desquamation of cells lining seminiferous tubules were observed in two infected calves. Consolidation of lungs with interstitial pneumonia, mild gastroenteritis and systemic spread were also evident. It was concluded that Indian BVDV isolate induced moderate clinical disease in calves and glomerulonephritis resulting from acute BVDV infection was observed for the first time. PMID:17383693

  6. Infection with chicken anaemia virus impairs the generation of pathogen-specific cytotoxic T lymphocytes

    PubMed Central

    Markowski-Grimsrud, Carrie J; Schat, Karel A

    2003-01-01

    Infection with chicken anaemia virus (CAV), a circovirus, can result in immunosuppression and subsequent increased susceptibility to secondary infections. This is the first report of impairment of pathogen-specific cytotoxic T lymphocytes (CTL) after natural and experimental infection of chickens with CAV and Marek's disease virus (MDV) or reticuloendotheliosis virus (REV). MDV- and REV-specific CTL were generated at 7 days post infection by 9–30-day-old-chickens that were positive for maternal antibodies to CAV at 9–17 days of age. Replication of CAV could not be demonstrated in these chickens using quantitative real-time polymerase chain reaction (PCR) and reverse transcriptase (RT)–PCR assays. In contrast, REV-specific CTL failed to develop when chickens negative for maternal antibodies at 9–17 days of age were infected. Infection with CAV at 45 days of age after CAV maternal antibodies had waned also caused a decreased REV-specific CTL response. In these chickens increased levels of CAV DNA of up to 107 copy numbers per µg DNA and increased relative transcript levels of CAV by up to a factor of 106 were detected by quantitative real-time PCR and RT–PCR. Interleukin (IL)-1β and IL-2 mRNA levels were not significantly affected by CAV infection at 7 or 14 days p.i. Similar assays for interferon-γ (IFN-γ) transcripts demonstrated a 10-fold increase in IFN-γ mRNA levels at 7 days post infection following REV or REV + CAV infection, while CAV alone caused a two- to fourfold increase. These results show a strong link between CAV antibody status, CAV replication, and the ability to generate REV-specific CTL. It is likely that the immunosuppressive effects of subclinical infection have previously been underestimated. PMID:12757624

  7. The type I interferon response bridles rabies virus infection and reduces pathogenicity.

    PubMed

    Chopy, Damien; Detje, Claudia N; Lafage, Mireille; Kalinke, Ulrich; Lafon, Monique

    2011-08-01

    Rabies virus (RABV) is a neurotropic virus transmitted by the bite of an infected animal that triggers a fatal encephalomyelitis. During its migration in the nervous system (NS), RABV triggers an innate immune response, including a type I IFN response well known to limit viral infections. We showed that although the neuroinvasive RABV strain CVS-NIV dampens type I IFN signaling by inhibiting IRF3 phosphorylation and STAT2 translocation, an early and transient type I IFN response is still triggered in the infected neuronal cells and NS. This urged us to investigate the role of type I IFN on RABV infection. We showed that primary mouse neurons (DRGs) of type I IFN(α/β) receptor deficient mice (IFNAR(-/-) mice) were more susceptible to RABV than DRGs of WT mice. In addition, exogenous type I IFN is partially efficient in preventing and slowing down infection in human neuroblastoma cells. Intra-muscular inoculation of type I IFNAR deficient mice [IFNAR(-/-) mice and NesCre ((+/-)) IFNAR ((flox/flox)) mice lacking IFNAR in neural cells of neuroectodermal origin only] with RABV reveals that the type I IFN response limits RABV dissemination in the inoculated muscle, slows down invasion of the spinal cord, and delays mortality. Thus, the type I IFN which is still produced in the NS during RABV infection is efficient enough to reduce neuroinvasiveness and pathogenicity and partially protect the host from fatal infection. PMID:21805057

  8. Neuropathogenesis of a highly pathogenic avian influenza virus (H7N1) in experimentally infected chickens

    PubMed Central

    2011-01-01

    In order to understand the mechanism of neuroinvasion of a highly pathogenic avian influenza virus (HPAIV) into the central nervous system (CNS) of chickens, specific pathogen free chickens were inoculated with a H7N1 HPAIV. Blood, cerebrospinal fluid (CSF), nasal cavity and brain tissue samples were obtained from 1 to 4 days post-inoculation (dpi) of infected and control chickens. Viral antigen topographical distribution, presence of influenza A virus receptors in the brain, as well as, the role of the olfactory route in virus CNS invasion were studied using different immunohistochemistry techniques. Besides, viral RNA load in CSF and blood was quantified by means of a quantitative real-time reverse transcription-polymerase chain reaction. Viral antigen was observed widely distributed in the CNS, showing bilateral and symmetrical distribution in the nuclei of the diencephalon, mesencephalon and rhombencephalon. Viral RNA was detected in blood and CSF at one dpi, indicating that the virus crosses the blood-CSF-barrier early during infection. This early dissemination is possibly favoured by the presence of Siaα2,3 Gal and Siaα2,6 Gal receptors in brain vascular endothelial cells, and Siaα2,3 Gal receptors in ependymal and choroid plexus cells. No viral antigen was observed in olfactory sensory neurons, while the olfactory bulb showed only weak staining, suggesting that the virus did not use this pathway to enter into the brain. The sequence of virus appearance and the topographical distribution of this H7N1 HPAIV indicate that the viral entry occurs via the haematogenous route, with early and generalized spreading through the CSF. PMID:21982125

  9. Plasmacytoid Dendritic Cell Infection and Sensing Capacity during Pathogenic and Nonpathogenic Simian Immunodeficiency Virus Infection

    PubMed Central

    Jochems, Simon P.; Jacquelin, Beatrice; Chauveau, Lise; Huot, Nicolas; Petitjean, Gaël; Lepelley, Alice; Liovat, Anne-Sophie; Ploquin, Mickaël J.; Cartwright, Emily K.; Bosinger, Steven E.; Silvestri, Guido; Barré-Sinoussi, Françoise; Lebon, Pierre; Schwartz, Olivier

    2015-01-01

    ABSTRACT Human immunodeficiency virus (HIV) in humans and simian immunodeficiency virus (SIV) in macaques (MAC) lead to chronic inflammation and AIDS. Natural hosts, such as African green monkeys (AGM) and sooty mangabeys (SM), are protected against SIV-induced chronic inflammation and AIDS. Here, we report that AGM plasmacytoid dendritic cells (pDC) express extremely low levels of CD4, unlike MAC and human pDC. Despite this, AGM pDC efficiently sensed SIVagm, but not heterologous HIV/SIV isolates, indicating a virus-host adaptation. Moreover, both AGM and SM pDC were found to be, in contrast to MAC pDC, predominantly negative for CCR5. Despite such limited CD4 and CCR5 expression, lymphoid tissue pDC were infected to a degree similar to that seen with CD4+ T cells in both MAC and AGM. Altogether, our finding of efficient pDC infection by SIV in vivo identifies pDC as a potential viral reservoir in lymphoid tissues. We discovered low expression of CD4 on AGM pDC, which did not preclude efficient sensing of host-adapted viruses. Therefore, pDC infection and efficient sensing are not prerequisites for chronic inflammation. The high level of pDC infection by SIVagm suggests that if CCR5 paucity on immune cells is important for nonpathogenesis of natural hosts, it is possibly not due to its role as a coreceptor. IMPORTANCE The ability of certain key immune cell subsets to resist infection might contribute to the asymptomatic nature of simian immunodeficiency virus (SIV) infection in its natural hosts, such as African green monkeys (AGM) and sooty mangabeys (SM). This relative resistance to infection has been correlated with reduced expression of CD4 and/or CCR5. We show that plasmacytoid dendritic cells (pDC) of natural hosts display reduced CD4 and/or CCR5 expression, unlike macaque pDC. Surprisingly, this did not protect AGM pDC, as infection levels were similar to those found in MAC pDC. Furthermore, we show that AGM pDC did not consistently produce type I

  10. Immune responses in piglets infected with highly pathogenic porcine reproductive and respiratory syndrome virus.

    PubMed

    Wang, Gang; Song, Tengfei; Yu, Ying; Liu, Yonggang; Shi, Wenda; Wang, Shujie; Rong, Fulong; Dong, Jianguo; Liu, He; Cai, Xuehui; Zhou, En-Min

    2011-08-15

    Porcine reproductive and respiratory syndrome virus (PRRSV) infection compromises the host's innate and adaptive immunity. The aim of this study was to investigate the immune responses of piglets infected with highly pathogenic (HP) PRRSV (HuN4 strain) with or without the immunization with CH-1R attenuated PRRSV vaccine. The response was evaluated for the clinical signs, pathological changes and virus load in immune organs, antibody responses and levels of serum IFN-γ, IL-4 and IL-10. The result showed that in comparison with the piglets received the immunization, the piglets infected with HP-PRRSV alone had the thymus atrophy, decreased serum levels of IL-4 and increased serum levels of IL-10 and INF-γ. These results suggest that elevated IL-10 levels at the early stage of the infection may enhance virus survival and delay the induction of protective immunity, while increased levels of IL-4 induce the effective immune responses and increase the animals' health status. PMID:21612828

  11. Pathogenic influenza B virus in the ferret model establishes lower respiratory tract infection

    PubMed Central

    Huang, Stephen S. H.; Banner, David; Paquette, Stephane G.; Leon, Alberto J.; Kelvin, Alyson A.

    2014-01-01

    Influenza B viruses have become increasingly more prominent during influenza seasons. Influenza B infection is typically considered a mild disease and receives less attention than influenza A, but has been causing 20 to 50 % of the total influenza incidence in several regions around the world. Although there is increasing evidence of mid to lower respiratory tract diseases such as bronchitis and pneumonia in influenza B patients, little is known about the pathogenesis of recent influenza B viruses. Here we investigated the clinical and pathological profiles of infection with strains representing the two current co-circulating B lineages (B/Yamagata and B/Victoria) in the ferret model. Specifically, we studied two B/Victoria (B/Brisbane/60/2008 and B/Bolivia/1526/2010) and two B/Yamagata (B/Florida/04/2006 and B/Wisconsin/01/2010) strain infections in ferrets and observed strain-specific but not lineage-specific pathogenicity. We found B/Brisbane/60/2008 caused the most severe clinical illness and B/Brisbane/60/2008 and the B/Yamagata strains instigated pathology in the middle to lower respiratory tract. Importantly, B/Brisbane/60/2008 established efficient lower respiratory tract infection with high viral burden. Our phylogenetic analyses demonstrate profound reassortment among recent influenza B viruses, which indicates the genetic make-up of B/Brisbane/60/2008 differs from the other strains. This may explain the pathogenicity difference post-infection in ferrets. PMID:24989173

  12. Homo- and Heterosubtypic Low Pathogenic Avian Influenza Exposure on H5N1 Highly Pathogenic Avian Influenza Virus Infection in Wood Ducks (Aix sponsa)

    PubMed Central

    Costa, Taiana P.; Brown, Justin D.; Howerth, Elizabeth W.; Stallknecht, David E.; Swayne, David E.

    2011-01-01

    Wild birds in the Orders Anseriformes and Charadriiformes are the natural reservoirs for avian influenza (AI) viruses. Although they are often infected with multiple AI viruses, the significance and extent of acquired immunity in these populations is not understood. Pre-existing immunity to AI virus has been shown to modulate the outcome of a highly pathogenic avian influenza (HPAI) virus infection in multiple domestic avian species, but few studies have addressed this effect in wild birds. In this study, the effect of pre-exposure to homosubtypic (homologous hemagglutinin) and heterosubtypic (heterologous hemagglutinin) low pathogenic avian influenza (LPAI) viruses on the outcome of a H5N1 HPAI virus infection in wood ducks (Aix sponsa) was evaluated. Pre-exposure of wood ducks to different LPAI viruses did not prevent infection with H5N1 HPAI virus, but did increase survival associated with H5N1 HPAI virus infection. The magnitude of this effect on the outcome of the H5N1 HPAI virus infection varied between different LPAI viruses, and was associated both with efficiency of LPAI viral replication in wood ducks and the development of a detectable humoral immune response. These observations suggest that in naturally occurring outbreaks of H5N1 HPAI, birds with pre-existing immunity to homologous hemagglutinin or neuraminidase subtypes of AI virus may either survive H5N1 HPAI virus infection or live longer than naïve birds and, consequently, could pose a greater risk for contributing to viral transmission and dissemination. The mechanisms responsible for this protection and/or the duration of this immunity remain unknown. The results of this study are important for surveillance efforts and help clarify epidemiological data from outbreaks of H5N1 HPAI virus in wild bird populations. PMID:21253608

  13. Systemic virus distribution and host responses in brain and intestine of chickens infected with low pathogenic or high pathogenic avian influenza virus

    PubMed Central

    2012-01-01

    Background Avian influenza virus (AIV) is classified into two pathotypes, low pathogenic (LP) and high pathogenic (HP), based on virulence in chickens. Differences in pathogenicity between HPAIV and LPAIV might eventually be related to specific characteristics of strains, tissue tropism and host responses. Methods To study differences in disease development between HPAIV and LPAIV, we examined the first appearance and eventual load of viral RNA in multiple organs as well as host responses in brain and intestine of chickens infected with two closely related H7N1 HPAIV or LPAIV strains. Results Both H7N1 HPAIV and LPAIV spread systemically in chickens after a combined intranasal/intratracheal inoculation. In brain, large differences in viral RNA load and host gene expression were found between H7N1 HPAIV and LPAIV infected chickens. Chicken embryo brain cell culture studies revealed that both HPAIV and LPAIV could infect cultivated embryonic brain cells, but in accordance with the absence of the necessary proteases, replication of LPAIV was limited. Furthermore, TUNEL assay indicated apoptosis in brain of HPAIV infected chickens only. In intestine, where endoproteases that cleave HA of LPAIV are available, we found minimal differences in the amount of viral RNA and a large overlap in the transcriptional responses between HPAIV and LPAIV infected chickens. Interestingly, brain and ileum differed clearly in the cellular pathways that were regulated upon an AI infection. Conclusions Although both H7N1 HPAIV and LPAIV RNA was detected in a broad range of tissues beyond the respiratory and gastrointestinal tract, our observations indicate that differences in pathogenicity and mortality between HPAIV and LPAIV could originate from differences in virus replication and the resulting host responses in vital organs like the brain. PMID:22390870

  14. The Nonstructural Proteins of Nipah Virus Play a Key Role in Pathogenicity in Experimentally Infected Animals

    PubMed Central

    Yoneda, Misako; Guillaume, Vanessa; Sato, Hiroki; Fujita, Kentaro; Georges-Courbot, Marie-Claude; Ikeda, Fusako; Omi, Mio; Muto-Terao, Yuri; Wild, T. Fabian; Kai, Chieko

    2010-01-01

    Nipah virus (NiV) P gene encodes P protein and three accessory proteins (V, C and W). It has been reported that all four P gene products have IFN antagonist activity when the proteins were transiently expressed. However, the role of those accessory proteins in natural infection with NiV remains unknown. We generated recombinant NiVs lacking V, C or W protein, rNiV(V−), rNiV(C−), and rNiV(W−), respectively, to analyze the functions of these proteins in infected cells and the implications in in vivo pathogenicity. All the recombinants grew well in cell culture, although the maximum titers of rNiV(V−) and rNiV(C−) were lower than the other recombinants. The rNiV(V−), rNiV(C−) and rNiV(W−) suppressed the IFN response as well as the parental rNiV, thereby indicating that the lack of each accessory protein does not significantly affect the inhibition of IFN signaling in infected cells. In experimentally infected golden hamsters, rNiV(V−) and rNiV(C−) but not the rNiV(W−) virus showed a significant reduction in virulence. These results suggest that V and C proteins play key roles in NiV pathogenicity, and the roles are independent of their IFN-antagonist activity. This is the first report that identifies the molecular determinants of NiV in pathogenicity in vivo. PMID:20856799

  15. Pathogenicity of Highly Pathogenic Avian Influenza Virus H5N1 in Naturally Infected Poultry in Egypt

    PubMed Central

    Hagag, Ibrahim Thabet; Mansour, Shimaa M. G.; Zhang, Zerui; Ali, Ahmed A. H.; Ismaiel, El-Bakry M.; Salama, Ali A.; Cardona, Carol J.; Collins, James; Xing, Zheng

    2015-01-01

    Highly pathogenic avian influenza virus (HPAIV) H5N1 has been endemic in Egypt since 2006, and there is increasing concern for its potential to become highly transmissible among humans. Infection by HPAIV H5N1 has been described in experimentally challenged birds. However, the pathogenicity of the H5N1 isolated in Egypt has never been reported in naturally infected chickens and ducks. Here we report a 2013 outbreak of HPAIV H5N1 in commercial poultry farms and backyards in Sharkia Province, Egypt. The main symptoms were ecchymosis on the shanks and feet, cyanosis of the comb and wattles, subcutaneous edema of the head and neck for chickens, and nervous signs (torticollis) for ducks. Within 48-72 hrs of the onset of illness, the average mortality rates were 22.8-30% and 28.5-40% in vaccinated chickens and non-vaccinated ducks, respectively. Tissue samples of chickens and ducks were collected for analyses with cross-section immunohistochemistry and real-time RT-PCR for specific viral RNA transcripts. While viral RNA was detected in nearly all tissues and sera collected, viral nucleoprotein was detected almost ubiquitously in all tissues, including testis. Interestingly, viral antigen was also observed in endothelial cells of most organs in chickens, and clearly detected in the trachea and brain in particular. Viral nucleoprotein was also detected in mononuclear cells of various organs, especially pulmonary tissue. We performed phylogenetic analyses and compared the genomic sequences of the hemagglutinin (HA) and nonstructural proteins (NS) among the isolated viruses, the HPAIV circulated in Egypt in the past and currently, and some available vaccine strains. Further analysis of deduced amino acids of both HA and NS1 revealed that our isolates carried molecular determinants of HPAIV, including the multibasic amino acids (PQGERRRK/KR*GLF) in the cleavage site in HA and glutamate at position 92 (D92E) in NS1. This is the first report of the pathogenicity of the HPAIVH5N

  16. Host Innate Immune Responses of Ducks Infected with Newcastle Disease Viruses of Different Pathogenicities

    PubMed Central

    Kang, Yinfeng; Li, Yanling; Yuan, Runyu; Feng, Minsha; Xiang, Bin; Sun, Minhua; Li, Yaling; Xie, Peng; Tan, Yangtong; Ren, Tao

    2015-01-01

    Though previous studies have identified two strains of duck-origin Newcastle disease virus (NDV) with varying levels of pathogenicity, the relationship between the early-phase host innate immune response, and pathogenesis of ducks infected with these strains in the lungs and thymuses remains unclear. In this study, we compared the viral distribution and mRNA expression of immune-related genes in ducks following infection with two NDV strains, Duck/CH/GD/SS/10 (SS-10) and Duck/CH/GD/NH/10 (NH-10). Both NDV strains replicated systemically in tested tissues (i.e., small intestine, cecal tonsils, brain, lung, bursa of Fabricius, thymus, and spleen) and exhibited different biological properties in duck pathogenicity. Real-time quantitative polymerase chain reaction showed that the expression of TLR3, TLR7, RIG-I, MDA5, IL-1β, IL-2, IL-6, IL-8, IFN-alpha, IFN-beta, IFN-gamma in the lungs was significantly greater than in the respective thymus genes during the early post infection stage. However, in the lungs, the expression of TLR3, TLR7, IL-1β, IL-2, IL-8, IFN-alpha, IFN-gamma, and MHC II induced by SS-10 at 72 h post-inoculation (hpi) was less than with NH-10. Furthermore, the expression of IL-6 and IFN-beta in the lungs and thymuses following infection with SS-10 was greater than that with NH-10 at 24 and 48 hpi. These results highlight important differences in host innate immune responses, courses of infection, and pathogenesis following NDV infection. Further studies should work to expand understandings of the molecular mechanisms related to NDV infection. PMID:26635752

  17. High Pathogenicity of Wild-Type Measles Virus Infection in CD150 (SLAM) Transgenic Mice

    PubMed Central

    Sellin, Caroline I.; Davoust, Nathalie; Guillaume, Vanessa; Baas, Dominique; Belin, Marie-Françoise; Buckland, Robin; Wild, T. Fabian; Horvat, Branka

    2006-01-01

    Measles virus (MV) infection causes an acute childhood disease, associated in certain cases with infection of the central nervous system and development of a severe neurological disease. We have generated transgenic mice ubiquitously expressing the human protein SLAM (signaling lymphocytic activation molecule), or CD150, recently identified as an MV receptor. In contrast to all other MV receptor transgenic models described so far, in these mice infection with wild-type MV strains is highly pathogenic. Intranasal infection of SLAM transgenic suckling mice leads to MV spread to different organs and the development of an acute neurological syndrome, characterized by lethargy, seizures, ataxia, weight loss, and death within 3 weeks. In addition, in this model, vaccine and wild-type MV strains can be distinguished by virulence. Furthermore, intracranial MV infection of adult transgenic mice generates a subclinical infection associated with a high titer of MV-specific antibodies in the serum. Finally, to analyze new antimeasles therapeutic approaches, we created a recombinant soluble form of SLAM and demonstrated its important antiviral activity both in vitro and in vivo. Taken together, our results show the high susceptibility of SLAM transgenic mice to MV-induced neurological disease and open new perspectives for the analysis of the implication of SLAM in the neuropathogenicity of other morbilliviruses, which also use this molecule as a receptor. Moreover, this transgenic model, in allowing a simple readout of the efficacy of an antiviral treatment, provides unique experimental means to test novel anti-MV preventive and therapeutic strategies. PMID:16775330

  18. Transmission of an H5N8-Subtype Highly Pathogenic Avian Influenza Virus from Infected Hens to Laid Eggs.

    PubMed

    Uchida, Yuko; Takemae, Nobuhiro; Tanikawa, Taichiro; Kanehira, Katsushi; Saito, Takehiko

    2016-06-01

    We showed here that an H5N8-subtype highly pathogenic avian influenza virus (HPAIV) was transmitted to both the internal contents and shells of eggs laid by white leghorn hens experimentally infected with the virus. Seven of eight HPAIV-infected hens laid eggs until 4 days postinoculation (dpi). The mean number of eggs laid per head daily decreased significantly from 0.58 before inoculation to 0.18 after viral inoculation. The virus was detected in the eggs laid by three of the seven hens. Viral transmission was detectable beginning on 3 dpi, and virus titers in tracheal and cloacal swabs from the hens that laid the contaminated eggs exceeded 2.9 log10 EID50. The level of viral replication and its timing when virus replicates enough to be detected in oviduct after virus inoculation appear to be key factors in the transmission of H5N8 HPAIV from infected hens to laid eggs. PMID:27309286

  19. Three-Dimensional Structure of a Protozoal Double-Stranded RNA Virus That Infects the Enteric Pathogen Giardia lamblia

    PubMed Central

    Janssen, Mandy E. W.; Takagi, Yuko; Parent, Kristin N.; Cardone, Giovanni

    2014-01-01

    ABSTRACT Giardia lamblia virus (GLV) is a small, nonenveloped, nonsegmented double-stranded RNA (dsRNA) virus infecting Giardia lamblia, the most common protozoan pathogen of the human intestine and a major agent of waterborne diarrheal disease worldwide. GLV (genus Giardiavirus) is a member of family Totiviridae, along with several other groups of protozoal or fungal viruses, including Leishmania RNA viruses and Trichomonas vaginalis viruses. Interestingly, GLV is more closely related than other Totiviridae members to a group of recently discovered metazoan viruses that includes penaeid shrimp infectious myonecrosis virus (IMNV). Moreover, GLV is the only known protozoal dsRNA virus that can transmit efficiently by extracellular means, also like IMNV. In this study, we used transmission electron cryomicroscopy and icosahedral image reconstruction to examine the GLV virion at an estimated resolution of 6.0 Å. Its outermost diameter is 485 Å, making it the largest totivirus capsid analyzed to date. Structural comparisons of GLV and other totiviruses highlighted a related “T=2” capsid organization and a conserved helix-rich fold in the capsid subunits. In agreement with its unique capacity as a protozoal dsRNA virus to survive and transmit through extracellular environments, GLV was found to be more thermoresistant than Trichomonas vaginalis virus 1, but no specific protein machinery to mediate cell entry, such as the fiber complexes in IMNV, could be localized. These and other structural and biochemical findings provide a basis for future work to dissect the cell entry mechanism of GLV into a “primitive” (early-branching) eukaryotic host and an important enteric pathogen of humans. IMPORTANCE Numerous pathogenic bacteria, including Corynebacterium diphtheriae, Salmonella enterica, and Vibrio cholerae, are infected with lysogenic bacteriophages that contribute significantly to bacterial virulence. In line with this phenomenon, several pathogenic protozoa

  20. Susceptibility And Adaptation Of A Mallard H5N2 Low Pathogenic Influenza Virus In Chickens Infected With Infectious Bursal Disease Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The influenza A/Mallard/Pennsylvania/12180/1984 (H5N2) virus is unable to replicate in 2 to 4-week old normal, immunocompetent specific-pathogen-free (SPF) chickens. In contrast, this mallard virus shows limited replication in chickens that had been previously infected with the immunosuppressive age...

  1. Evidence of Infection by H5N2 Highly Pathogenic Avian Influenza Viruses in Healthy Wild Waterfowl

    PubMed Central

    Hammoumi, Saliha; Newman, Scott H.; Hagemeijer, Ward; Takekawa, John Y.; Cappelle, Julien; Dodman, Tim; Joannis, Tony; Gil, Patricia; Monne, Isabella; Fusaro, Alice; Capua, Ilaria; Manu, Shiiwuua; Micheloni, Pierfrancesco; Ottosson, Ulf; Mshelbwala, John H.; Lubroth, Juan; Domenech, Joseph; Monicat, François

    2008-01-01

    The potential existence of a wild bird reservoir for highly pathogenic avian influenza (HPAI) has been recently questioned by the spread and the persisting circulation of H5N1 HPAI viruses, responsible for concurrent outbreaks in migratory and domestic birds over Asia, Europe, and Africa. During a large-scale surveillance programme over Eastern Europe, the Middle East, and Africa, we detected avian influenza viruses of H5N2 subtype with a highly pathogenic (HP) viral genotype in healthy birds of two wild waterfowl species sampled in Nigeria. We monitored the survival and regional movements of one of the infected birds through satellite telemetry, providing a rare evidence of a non-lethal natural infection by an HP viral genotype in wild birds. Phylogenetic analysis of the H5N2 viruses revealed close genetic relationships with H5 viruses of low pathogenicity circulating in Eurasian wild and domestic ducks. In addition, genetic analysis did not reveal known gallinaceous poultry adaptive mutations, suggesting that the emergence of HP strains could have taken place in either wild or domestic ducks or in non-gallinaceous species. The presence of coexisting but genetically distinguishable avian influenza viruses with an HP viral genotype in two cohabiting species of wild waterfowl, with evidence of non-lethal infection at least in one species and without evidence of prior extensive circulation of the virus in domestic poultry, suggest that some strains with a potential high pathogenicity for poultry could be maintained in a community of wild waterfowl. PMID:18704172

  2. Evidence of infection by H5N2 highly pathogenic avian influenza viruses in healthy wild waterfowl

    USGS Publications Warehouse

    Gaidet, N.; Cattoli, G.; Hammoumi, S.; Newman, S.H.; Hagemeijer, W.; Takekawa, J.Y.; Cappelle, J.; Dodman, T.; Joannis, T.; Gil, P.; Monne, I.; Fusaro, A.; Capua, I.; Manu, S.; Micheloni, P.; Ottosson, U.; Mshelbwala, J.H.; Lubroth, J.; Domenech, J.; Monicat, F.

    2008-01-01

    The potential existence of a wild bird reservoir for highly pathogenic avian influenza (HPAI) has been recently questioned by the spread and the persisting circulation of H5N1 HPAI viruses, responsible for concurrent outbreaks in migratory and domestic birds over Asia, Europe, and Africa. During a large-scale surveillance programme over Eastern Europe, the Middle East, and Africa, we detected avian influenza viruses of H5N2 subtype with a highly pathogenic (HP) viral genotype in healthy birds of two wild waterfowl species sampled in Nigeria. We monitored the survival and regional movements of one of the infected birds through satellite telemetry, providing a rare evidence of a non-lethal natural infection by an HP viral genotype in wild birds. Phylogenetic analysis of the H5N2 viruses revealed close genetic relationships with H5 viruses of low pathogenicity circulating in Eurasian wild and domestic ducks. In addition, genetic analysis did not reveal known gallinaceous poultry adaptive mutations, suggesting that the emergence of HP strains could have taken place in either wild or domestic ducks or in non-gallinaceous species. The presence of coexisting but genetically distinguishable avian influenza viruses with an HP viral genotype in two cohabiting species of wild waterfowl, with evidence of non-lethal infection at least in one species and without evidence of prior extensive circulation of the virus in domestic poultry, suggest that some strains with a potential high pathogenicity for poultry could be maintained in a community of wild waterfowl.

  3. In Vitro and In Vivo Infectivity and Pathogenicity of the Lymphoid Cell-Derived Woodchuck Hepatitis Virus

    PubMed Central

    Lew, Yuan-Yee; Michalak, Tomasz I.

    2001-01-01

    Woodchuck hepatitis virus (WHV) and human hepatitis B virus are closely related, highly hepatotropic mammalian DNA viruses that also replicate in the lymphatic system. The infectivity and pathogenicity of hepadnaviruses propagating in lymphoid cells are under debate. In this study, hepato- and lymphotropism of WHV produced by naturally infected lymphoid cells was examined in specifically established woodchuck hepatocyte and lymphoid cell cultures and coculture systems, and virus pathogenicity was tested in susceptible animals. Applying PCR-based assays discriminating between the total pool of WHV genomes and covalently closed circular DNA (cccDNA), combined with enzymatic elimination of extracellular viral sequences potentially associated with the cell surface, our study documents that virus replicating in woodchuck lymphoid cells is infectious to homologous hepatocytes and lymphoid cells in vitro. The productive replication of WHV from lymphoid cells in cultured hepatocytes was evidenced by the appearance of virus-specific DNA, cccDNA, and antigens, transmissibility of the virus through multiple passages in hepatocyte cultures, and the ability of the passaged virus to infect virus-naive animals. The data also revealed that WHV from lymphoid cells can initiate classical acute viral hepatitis in susceptible animals, albeit small quantities (∼103 virions) caused immunovirologically undetectable (occult) WHV infection that engaged the lymphatic system but not the liver. Our results provide direct in vitro and in vivo evidence that lymphoid cells in the infected host support propagation of infectious hepadnavirus that has the potential to induce hepatitis. They also emphasize a principal role of the lymphatic system in the maintenance and dissemination of hepadnavirus infection, particularly when infection is induced by low virus doses. PMID:11160675

  4. THERMAL INACTIVATION OF H5N1 HIGH PATHOGENICITY AVIAN INFLUENZA VIRUS IN NATURALLY INFECTED CHICKEN MEAT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thermal inactivation of the H5N1 high pathogenicity avian influenza (HPAI) virus strain A/chicken/Korea/ES/2003 (Korea/03) was quantitatively measured in thigh and breast meat harvested from infected chickens. The average Korea/03 titers in uncooked meat samples were 8.0 log 10 EID50/g (thigh) and 7...

  5. Experimental co-infections of domestic ducks with a virulent Newcastle disease virus and low or highly pathogenic avian influenza viruses

    PubMed Central

    Pantin-Jackwood, Mary; Costa-Hurtado, Mar; Miller, Patti J.; Afonso, Claudio L.; Spackman, Erica; Kapczynski, Darrell; Shepherd, Eric; Smith, Diane; Swayne, David

    2015-01-01

    Infections with avian influenza viruses (AIV) of low and high pathogenicity (LP and HP) and Newcastle disease virus (NDV) are commonly reported in domestic ducks in many parts of the world. However, it’s not clear if co-infections with these viruses affect the severity of the diseases they produce, the amount of virus shed, and transmission of the viruses. In this study we infected domestic ducks with a virulent NDV virus (vNDV) and either a LPAIV or a HPAIV by giving the viruses individually, simultaneously, or sequentially two days apart. No clinical signs were observed in ducks infected or co-infected with vNDV and LPAIV, but co-infection decreased the number of ducks shedding vNDV and the amount of virus shed (P <0.01) at 4 days post inoculation (dpi). Co-infection didn’t affect the number of birds shedding LPAIV, but more LPAIV was shed at 2 dpi (P <0.0001) from ducks inoculated with only LPAIV compared to ducks co-infected with vNDV. Ducks that received the HPAIV with the vNDV simultaneously survived fewer days (P <0.05) compared to the ducks that received the vNDV two days before the HPAIV. Co-infection also reduced transmission of vNDV to naïve contact ducks housed with the inoculated ducks. In conclusion, domestic ducks can become co-infected with vNDV and LPAIV with no effect on clinical signs but with reduction of virus shedding and transmission. These findings indicate that infection with one virus can interfere with replication of another, modifying the pathogenesis and transmission of the viruses. PMID:25759292

  6. Highly pathogenic porcine reproductive and respiratory syndrome virus infection and induction of apoptosis in bone marrow cells of infected piglets.

    PubMed

    Wang, Gang; Li, Li; Yu, Ying; Tu, Yabin; Tong, Jie; Zhang, Chong; Liu, Yonggang; Li, Yuming; Han, Zifeng; Jiang, Chenggang; Wang, Shujie; Zhou, En-Min; He, Xijun; Cai, Xuehui

    2016-06-01

    Highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) has been shown to have a wide range of tissue tropism, and can directly and indirectly induce cellular apoptosis. However, the impact of HP-PRRSV infection on the bone marrow (BM) of piglets remains unclear. In this study, we investigated the BM as a novel site of infection by the HP-PRRSV strain in piglets. HP-PRRSV infected SWC3+SWC8- cells in the BM and induced BM cells to undergo apoptosis. The number of apoptotic cells highlights the striking effects of HP-PRRSV on the central immune organs (BM and thymus) that may enhance the susceptibility of pigs to secondary infections and lead to high mortality. This study is, to the best of our knowledge, the first to report the impact of HP-PRRSV on the BM and implicate the depletion of BM cells during HP-PRRSV infection in the development of immunosuppression in this disease. PMID:26963602

  7. Variability in pathobiology of South Korean H5N1 high-pathogenicity avian influenza virus infection for 5 species of migratory waterfowl

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The biological outcome of H5N1 high pathogenicity avian influenza (HPAI) virus infection in wild waterfowl is poorly understood. This study examined infectivity and pathobiology of A/chicken/Korea/IS/06 (H5N1) HPAI virus infection in Mute swans (Cygnus olor), Greylag geese (Anser anser), Ruddy Sheld...

  8. Experimental infection of SPF and Korean native chickens with highly pathogenic avian influenza virus (H5N8).

    PubMed

    Lee, Eun-Kyoung; Song, Byung-Min; Kang, Hyun-Mi; Woo, Sang-Hee; Heo, Gyeong-Beom; Jung, Suk Chan; Park, Yong Ho; Lee, Youn-Jeong; Kim, Jae-Hong

    2016-05-01

    In 2014, an H5N8 outbreak of highly pathogenic avian influenza (HPAI) occurred in South Korea. The H5N8 strain produced mild to moderate clinical signs and mortality rates in commercial chicken farms, especially Korean native chicken farms. To understand the differences between their pathogenicity in SPF chicken and Korean native chicken., we evaluated the mean bird lethal doses (BLD50) of the Korean representative H5N8 virus (A/broiler duck/Korea/Buan2/2014) The BLD50values of the H5N8 virus were 10(5.3)EID50and 10(6.7)EID50in SPF and Korean native chickens, respectively. In addition, the mean death time was much longer, and the viral titers in tissues of H5N8-infected chickens were significantly lower, in the Korean group than in the SPF group. These features of the H5N8 virus likely account for its mild-to-moderate pathogenicity in commercial chicken farms, especially Korean native chicken flocks, despite the fact that it is a highly pathogenic virus according to the OIE criteria. To improve current understanding and management of HPAI, pathogenic characterization of novel emerging viruses should be performed by natural route in major poultry species in each country. PMID:26933235

  9. First reported detection of a low pathogenicity avian influenza virus subtype H9 infection in domestic fowl in England.

    PubMed

    Parker, C D; Reid, S M; Ball, A; Cox, W J; Essen, S C; Hanna, A; Mahmood, S; Slomka, M J; Irvine, R M; Brown, I H

    2012-10-13

    In December 2010, infection with a H9N1 low pathogenicity avian influenza (LPAI) virus was detected in a broiler breeder flock in East Anglia. Disease suspicion was based on acute drops in egg production in two of four sheds on the premises, poor egg shell quality and evidence of diarrhoea. H9N1 LPAI virus infection was confirmed by real-time reverse transcription PCR. Sequencing revealed high nucleotide identity of 93.6 per cent and 97.9 per cent with contemporary North American H9 and Eurasian N1 genes, respectively. Attempted virus isolation in embryonated specific pathogen free (SPF) fowls' eggs was unsuccessful. Epidemiological investigations were conducted to identify the source of infection and any onward spread. These concluded that infection was restricted to the affected premises, and no contacts or movements of poultry, people or fomites could be attributed as the source of infection. However, the infection followed a period of extremely cold weather and snow which impacted on the biosecurity protocols on site, and also led to increased wild bird activity locally, including waterfowl and game birds around the farm buildings. Analysis of the N1 gene sequence suggested direct introduction from wild birds. Although H9 infection in poultry is not notifiable, H9N2 LPAI viruses have been associated with production and mortality episodes in poultry in many parts of Asia and the Middle East. In the present H9N1 outbreak, clinical signs were relatively mild in the poultry with no mortality, transient impact on egg production and no indication of zoonotic spread. However, this first reported detection of H9 LPAI virus in chickens in England was also the first H9 UK poultry case for 40 years, and vindicates the need for continued vigilance and surveillance of avian influenza viruses in poultry populations. PMID:22949546

  10. Low pathogenicity avian influenza viruses infect chicken layers by different routes of inoculation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order to develop better control measures against avian influenza (AI) it’s necessary to understand how the virus transmits in poultry. In a previous study in which the infectivity and transmissibility of the pandemic H1N1influenza virus was examined in different poultry species, we found that no ...

  11. Pathobiology of Asian highly pathogenic avian influenza H5N1 virus infection in ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ducks and other wild aquatic birds are the natural reservoir of influenza type A viruses which normally are nonpathogenic in these birds. However, the Asian H5N1 avian influenza (AI) viruses have evolved from producing no disease or mild respiratory infections in ducks, to some strains producing se...

  12. Prevention of immunodeficiency virus induced CD4+ T-cell depletion by prior infection with a non-pathogenic virus

    SciTech Connect

    TerWee, Julie A.; Carlson, Jennifer K.; Sprague, Wendy S.; Sondgeroth, Kerry S.; Shropshire, Sarah B.; Troyer, Jennifer L.; VandeWoude, Sue

    2008-07-20

    Immune dysregulation initiated by a profound loss of CD4+ T-cells is fundamental to HIV-induced pathogenesis. Infection of domestic cats with a non-pathogenic lentivirus prevalent in the puma (puma lentivirus, PLV or FIV{sub PCO}) prevented peripheral blood CD4+ T-cell depletion caused by subsequent virulent FIV infection. Maintenance of this critical population was not associated with a significant decrease in FIV viremia, lending support to the hypothesis that direct viral cytopathic effect is not the primary cause of immunodeficiency. Although this approach was analogous to immunization with a modified live vaccine, correlates of immunity such as a serum-neutralizing antibody or virus-specific T-cell proliferative response were not found in protected animals. Differences in cytokine transcription profile, most notably in interferon gamma, were observed between the protected and unprotected groups. These data provide support for the importance of non-adaptive enhancement of the immune response in the prevention of CD4+ T-cell loss.

  13. H5N1 highly pathogenic avian influenza virus experimental infection trials in wild birds: what have we learned and what questions remain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Prior to 2002, there were very few reports of highly pathogenic avian influenza (HPAI) virus infections in wild birds. Since 2002; however, a variety of wild avian species have died from infection with Asian lineage H5N1 HPAI viruses and a growing body of evidence suggests migratory waterfowl may h...

  14. Ostrich ( Struthio camelus ) Infected with H5N8 Highly Pathogenic Avian Influenza Virus in South Korea in 2014.

    PubMed

    Kim, Hye-Ryoung; Kwon, Yong-Kuk; Lee, Youn-Jeong; Kang, Hyun-Mi; Lee, Eun-Kyoung; Song, Byung-Min; Jung, Suk-Chan; Lee, Kyung-Hyun; Lee, Hyun-Kyoung; Baek, Kang-Hyun; Bae, You-Chan

    2016-06-01

    Highly pathogenic avian influenza (HPAI) virus of the H5N8 subtype was isolated from a young ostrich in South Korea in March 2014. Clinical signs characterized by anorexia, depression, and signs of nervousness were observed. The isolated A/ostrich/Korea/H829/2014 (H5N8) virus had a cleavage site motif containing multiple basic amino acids, typical of HPAI virus. The phylogenetic tree of the hemagglutinin gene of the H5 HPAI virus showed that this ostrich H5N8 virus belongs to clade 2.3.4.4 viruses together with H5N8 strains isolated from ducks and wild birds in South Korea in 2014. Pathologically, redness of pancreas, enlargement and hemorrhage of spleen, friability of brain, and hydropericardium were prominently found. Histologic legions were observed in pancreas, spleen, liver, lung, heart, and brain, and influenza A nucleoproteins were detected in the same organs by immunohistochemistry. Other ostriches farmed together in open camps were not infected with HPAI virus based on the serologic and virologic tests. The findings indicate that ostriches are susceptible to H5N8 HPAI virus, but this virus does not spread efficiently among ratites. PMID:27309301

  15. Host Regulatory Network Response to Infection with Highly Pathogenic H5N1 Avian Influenza Virus ▿ †

    PubMed Central

    Li, Chengjun; Bankhead, Armand; Eisfeld, Amie J.; Hatta, Yasuko; Jeng, Sophia; Chang, Jean H.; Aicher, Lauri D.; Proll, Sean; Ellis, Amy L.; Law, G. Lynn; Waters, Katrina M.; Neumann, Gabriele; Katze, Michael G.; McWeeney, Shannon; Kawaoka, Yoshihiro

    2011-01-01

    During the last decade, more than half of humans infected with highly pathogenic avian influenza (HPAI) H5N1 viruses have died, yet virus-induced host signaling has yet to be clearly elucidated. Airway epithelia are known to produce inflammatory mediators that contribute to HPAI H5N1-mediated pathogenicity, but a comprehensive analysis of the host response in this cell type is lacking. Here, we leveraged a system approach to identify and statistically validate signaling subnetworks that define the dynamic transcriptional response of human bronchial epithelial cells after infection with influenza A/Vietnam/1203/2004 (H5N1, VN1203). Importantly, we validated a subset of transcripts from one subnetwork in both Calu-3 cells and mice. A more detailed examination of two subnetworks involved in the immune response and keratinization processes revealed potential novel mediators of HPAI H5N1 pathogenesis and host response signaling. Finally, we show how these results compare to those for a less virulent strain of influenza virus. Using emergent network properties, we provide fresh insight into the host response to HPAI H5N1 virus infection and identify novel avenues for perturbation studies and potential therapeutic interventions for fatal HPAI H5N1 disease. PMID:21865398

  16. 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...

  17. Previous infection with virulent strains of Newcastle disease virus reduces highly pathogenic avian influenza virus replication, disease, and mortality in chickens.

    PubMed

    Costa-Hurtado, Mar; Afonso, Claudio L; Miller, Patti J; Shepherd, Eric; Cha, Ra Mi; Smith, Diane; Spackman, Erica; Kapczynski, Darrell R; Suarez, David L; Swayne, David E; Pantin-Jackwood, Mary J

    2015-01-01

    Highly pathogenic avian influenza virus (HPAIV) and Newcastle disease virus (NDV) are two of the most important viruses affecting poultry worldwide and produce co-infections especially in areas of the world where both viruses are endemic; but little is known about the interactions between these two viruses. The objective of this study was to determine if co-infection with NDV affects HPAIV replication in chickens. Only infections with virulent NDV strains (mesogenic Pigeon/1984 or velogenic CA/2002), and not a lentogenic NDV strain (LaSota), interfered with the replication of HPAIV A/chicken/Queretaro/14588-19/95 (H5N2) when the H5N2 was given at a high dose (10(6.9) EID50) two days after the NDV inoculation, but despite this interference, mortality was still observed. However, chickens infected with the less virulent mesogenic NDV Pigeon/1984 strain three days prior to being infected with a lower dose (10(5.3-5.5) EID50) of the same or a different HPAIV, A/chicken/Jalisco/CPA-12283-12/2012 (H7N3), had reduced HPAIV replication and increased survival rates. In conclusion, previous infection of chickens with virulent NDV strains can reduce HPAIV replication, and consequently disease and mortality. This interference depends on the titer of the viruses used, the virulence of the NDV, and the timing of the infections. The information obtained from these studies helps to understand the possible interactions and outcomes of infection (disease and virus shedding) when HPAIV and NDV co-infect chickens in the field. PMID:26394750

  18. Rhesus macaques previously infected with simian/human immunodeficiency virus are protected from vaginal challenge with pathogenic SIVmac239.

    PubMed Central

    Miller, C J; McChesney, M B; Lü, X; Dailey, P J; Chutkowski, C; Lu, D; Brosio, P; Roberts, B; Lu, Y

    1997-01-01

    Nontraumatic vaginal inoculation of rhesus macaques with a simian/human immunodeficiency virus (SIV/HIV) chimera containing the envelope gene from HIV-1 89.6 (SHIV 89.6) results in systemic infection (Y. Lu, B. Brosio, M. Lafaile, J. Li, R. G. Collman, J. Sodroski, and C. J. Miller, J. Virol. 70:3045-3050, 1996). A total of five rhesus macaques have each been infected by exposure to at least three intravaginal inoculations of SHIV 89.6. The SHIV 89.6 infection is characterized by a transient viremia that evokes humoral and cellular immune responses to HIV and SIV antigens, but disease does not develop in animals infected with SHIV 89.6. To determine if a previous infection with SHIV 89.6 by vaginal inoculation could protect animals from vaginal challenge with pathogenic SIV, all five animals were intravaginally inoculated twice with pathogenic SIV-mac239. After challenge, all of the SHIV-immunized animals had low or undetectable viral RNA levels in plasma compared to control animals. Three of the five of the SHIV-immunized animals remained virus isolation negative for more than 8 months, while two became virus isolation positive. The presence of SIV Gag-specific cytotoxic T lymphocytes in peripheral blood mononuclear cells and SIV-specific antibodies in cervicovaginal secretions at the time of challenge was associated with resistance to pathogenic SIV infection after vaginal challenge. These results suggest that protection from sexual transmission of HIV may be possible by effectively stimulating both humoral and cellular antiviral immunity in the systemic and genital mucosal immune compartments. PMID:9032322

  19. Experimental co-infection of SPF chickens with low pathogenicity avian influenza virus (LPAIV) subtypes H9N2, H5N2 and H7N9, and infectious bronchitis virus (IBV)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus (AIV) and infectious bronchitis virus (IBV) are two of the most important respiratory viruses affecting poultry worldwide, but little is known about the effect of co-infection of these two viruses in poultry. Low pathogenicity (LP) AIV can produce from mild to moderate upper r...

  20. Re-evaluation of the pathogenic roles of nonstructural protein 1 and its antibodies during dengue virus infection.

    PubMed

    Chuang, Yung-Chun; Wang, Shu-Ying; Lin, Yee-Shin; Chen, Hong-Ru; Yeh, Trai-Ming

    2013-01-01

    Dengue virus (DENV) infection can cause life-threatening dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Vascular leakage and abnormal hemorrhage are the two major pathogenic changes found in these patients. From previous studies, it is known that both antibodies and cytokines induced in response to DENV infection are involved in the immunopathogenesis of DHF/DSS. However, the role of viral factors during DENV infection remains unclear. Nonstructural protein 1 (NS1), which is secreted in the sera of patients, is a useful diagnostic marker for acute DENV infection. Nevertheless, the roles of NS1 and its antibodies in the pathogenesis of DHF/DSS are unclear. The focus of this review is to evaluate the possible contributions of NS1 and the antibodies it induces to vascular leakage and abnormal hemorrhage during DENV infection, which may provide clues to better understanding the pathogenesis of DHF/DSS. PMID:23806052

  1. The Chinese highly pathogenic porcine reproductive and respiratory syndrome virus infection suppresses Th17 cells response in vivo.

    PubMed

    Zhang, Long; Zhou, Lei; Ge, Xinna; Guo, Xin; Han, Jun; Yang, Hanchun

    2016-06-30

    Porcine reproductive and respiratory syndrome virus (PRRSV) has been shown to immunomodulate innate and adaptive immunity of pigs. The Chinese highly pathogenic PRRSV (HP-PRRSV) infection causes severe bacterial secondary infection in pigs. However, the mechanism in relation to the bacterial secondary infection induced by HP-PRRSV remains unknown. In the present study, Th17 cells response in peripheral blood, lungs, spleens and lymph nodes of piglets were analyzed, and bacterial loads in lungs of piglets were examined upon HP-PRRSV infection. Meanwhile the changes of CD4(+) and CD8(+) T cells in peripheral blood of the inoculated piglets were analyzed. The results showed that HP-PRRSV-inoculated piglets exhibited a suppressed Th17 cells response in peripheral blood and a reduced number of Th17 cells in lungs, and higher bacterial loads in lungs, compared with low pathogenic PRRSV. Moreover, HP-PRRSV obviously resulted in severe depletion of porcine T cells in peripheral blood at the early stage of infection. These findings indicate that HP-PRRSV infection suppresses the response of Th17 cells that play an important role in combating bacterial infections, suggesting a possible correlation between the suppression of Th17 cells response in vivo and bacterial secondary infection induced by HP-PRRSV. Our present study adds a novel insight into better understanding of the pathogenesis of the Chinese HP-PRRSV. PMID:27259830

  2. Highly (H5N1) and low (H7N2) pathogenic avian influenza virus infection in falcons via nasochoanal route and ingestion of experimentally infected prey.

    PubMed

    Bertran, Kateri; Busquets, Núria; Abad, Francesc Xavier; García de la Fuente, Jorge; Solanes, David; Cordón, Iván; Costa, Taiana; Dolz, Roser; Majó, Natàlia

    2012-01-01

    An experimental infection with highly pathogenic avian influenza (HPAI) and low pathogenic avian influenza (LPAI) viruses was carried out on falcons in order to examine the effects of these viruses in terms of pathogenesis, viral distribution in tissues and viral shedding. The distribution pattern of influenza virus receptors was also assessed. Captive-reared gyr-saker (Falco rusticolus x Falco cherrug) hybrid falcons were challenged with a HPAI H5N1 virus (A/Great crested grebe/Basque Country/06.03249/2006) or a LPAI H7N2 virus (A/Anas plathyrhynchos/Spain/1877/2009), both via the nasochoanal route and by ingestion of previously infected specific pathogen free chicks. Infected falcons exhibited similar infection dynamics despite the different routes of exposure, demonstrating the effectiveness of in vivo feeding route. H5N1 infected falcons died, or were euthanized, between 5-7 days post-infection (dpi) after showing acute severe neurological signs. Presence of viral antigen in several tissues was confirmed by immunohistochemistry and real time RT-PCR (RRT-PCR), which were generally associated with significant microscopical lesions, mostly in the brain. Neither clinical signs, nor histopathological findings were observed in any of the H7N2 LPAI infected falcons, although all of them had seroconverted by 11 dpi. Avian receptors were strongly present in the upper respiratory tract of the falcons, in accordance with the consistent oral viral shedding detected by RRT-PCR in both H5N1 HPAI and H7N2 LPAI infected falcons. The present study demonstrates that gyr-saker hybrid falcons are highly susceptible to H5N1 HPAI virus infection, as previously observed, and that they may play a major role in the spreading of both HPAI and LPAI viruses. For the first time in raptors, natural infection by feeding on infected prey was successfully reproduced. The use of avian prey species in falconry husbandry and wildlife rehabilitation facilities could put valuable birds of prey and

  3. Effect of Infection with a Mesogenic Strain of Newcastle Disease Virus on Infection with Highly Pathogenic Avian Influenza Virus in Chickens.

    PubMed

    Costa-Hurtado, Mar; Afonso, Claudio L; Miller, Patti J; Shepherd, Eric; DeJesus, Eric; Smith, Diane; Pantin-Jackwood, Mary J

    2016-05-01

    Little is known on the interactions between avian influenza virus (AIV) and Newcastle disease virus (NDV) when coinfecting the same poultry host. In a previous study we found that infection of chickens with a mesogenic strain of NDV (mNDV) can reduce highly pathogenic AIV (HPAIV) replication, clinical disease, and mortality. This interaction depended on the titer of the viruses used and the timing of the infections. To further explore the effect of mNDV infectious dose in protecting chickens against HPAIV infection, 2-wk-old birds were inoculated with different doses of mNDV (10(4), 10(6), or 10(7) 50% embryo infective dose [EID50]) 3 days before inoculation with a HPAIV (10(5) or 10(6) EID50). Although birds coinfected with the higher mNDV doses (10(6) or 10(7)) survived for longer than birds inoculated only with HPAIV (10(5)), we did not observe the same protection with the lower dose of mNDV (10(4)) or when given the higher dose of HPAIV (10(6)), indicating that the relation between the titer of the two coinfecting viruses is determinant in the outcome. In a similar experiment, a higher number of 4-wk-old birds survived, and for longer, even when given higher HPAIV doses (10(6.3) and 10(7.3) EID50). In addition, we also examined the duration of protection provided by mNDV (10(7) EID50) on a HPAIV infection. Five-week-old chickens were inoculated with mNDV followed by inoculation with 10(6) EID50 of an HPAIV given at 2, 4, 6, or 9 days after the mNDV. HPAIV replication was affected and an increase in survival was found in all coinfected groups when compared to the HPAIV single-inoculated group, but the mortality in coinfected groups was high. In conclusion, previous inoculation with mNDV can affect HPAIV replication in chickens for at least 9 days, but this viral interference is titer dependent. PMID:27309067

  4. BOVINE VIRAL DIARRHEA VIRUS IN CAMELIDS: AN EMERGING PATHOGEN AND WAYS TO MONITOR HERD INFECTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The subject of this report will attempt to tie in several aspects of bovine viral diarrhea virus (BVDV) and its most recent incursion into the camelid family, namely llamas and alpacas. We have known that both llamas and alpacas are susceptible to BVDV infections for over 20 years. In some cases, ...

  5. Transmission of H5N1 high pathogenicity avian influenza virus to Herring gulls (Larus argentatus) through intranasal inoculation of virus and ingestion of virus-infected chicken meat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order to evaluate the susceptibility of herring gulls (Larus argentatus) to H5N1 highly pathogenic avian influenza (HPAI) virus under natural routes of infection, we exposed gulls to two Asian lineage H5N1 HPAI viruses (A/whooper swan/Mongolia/244/05 and A/duck meat/Anyang/AVL-1/01) via intranasa...

  6. Reassessing the role of the NLRP3 inflammasome during pathogenic influenza A virus infection via temporal inhibition.

    PubMed

    Tate, Michelle D; Ong, James D H; Dowling, Jennifer K; McAuley, Julie L; Robertson, Avril B; Latz, Eicke; Drummond, Grant R; Cooper, Matthew A; Hertzog, Paul J; Mansell, Ashley

    2016-01-01

    The inflammasome NLRP3 is activated by pathogen associated molecular patterns (PAMPs) during infection, including RNA and proteins from influenza A virus (IAV). However, chronic activation by danger associated molecular patterns (DAMPs) can be deleterious to the host. We show that blocking NLRP3 activation can be either protective or detrimental at different stages of lethal influenza A virus (IAV). Administration of the specific NLRP3 inhibitor MCC950 to mice from one day following IAV challenge resulted in hypersusceptibility to lethality. In contrast, delaying treatment with MCC950 until the height of disease (a more likely clinical scenario) significantly protected mice from severe and highly virulent IAV-induced disease. These findings identify for the first time that NLRP3 plays a detrimental role later in infection, contributing to IAV pathogenesis through increased cytokine production and lung cellular infiltrates. These studies also provide the first evidence identifying NLRP3 inhibition as a novel therapeutic target to reduce IAV disease severity. PMID:27283237

  7. Reassessing the role of the NLRP3 inflammasome during pathogenic influenza A virus infection via temporal inhibition

    PubMed Central

    Tate, Michelle D.; Ong, James D. H.; Dowling, Jennifer K.; McAuley, Julie L.; Robertson, Avril B.; Latz, Eicke; Drummond, Grant R.; Cooper, Matthew A.; Hertzog, Paul J.; Mansell, Ashley

    2016-01-01

    The inflammasome NLRP3 is activated by pathogen associated molecular patterns (PAMPs) during infection, including RNA and proteins from influenza A virus (IAV). However, chronic activation by danger associated molecular patterns (DAMPs) can be deleterious to the host. We show that blocking NLRP3 activation can be either protective or detrimental at different stages of lethal influenza A virus (IAV). Administration of the specific NLRP3 inhibitor MCC950 to mice from one day following IAV challenge resulted in hypersusceptibility to lethality. In contrast, delaying treatment with MCC950 until the height of disease (a more likely clinical scenario) significantly protected mice from severe and highly virulent IAV-induced disease. These findings identify for the first time that NLRP3 plays a detrimental role later in infection, contributing to IAV pathogenesis through increased cytokine production and lung cellular infiltrates. These studies also provide the first evidence identifying NLRP3 inhibition as a novel therapeutic target to reduce IAV disease severity. PMID:27283237

  8. Infection Risk for Persons Exposed to Highly Pathogenic Avian Influenza A H5 Virus-Infected Birds, United States, December 2014-March 2015.

    PubMed

    Arriola, Carmen S; Nelson, Deborah I; Deliberto, Thomas J; Blanton, Lenee; Kniss, Krista; Levine, Min Z; Trock, Susan C; Finelli, Lyn; Jhung, Michael A

    2015-12-01

    Newly emerged highly pathogenic avian influenza (HPAI) A H5 viruses have caused outbreaks among birds in the United States. These viruses differ genetically from HPAI H5 viruses that previously caused human illness, most notably in Asia and Africa. To assess the risk for animal-to-human HPAI H5 virus transmission in the United States, we determined the number of persons with self-reported exposure to infected birds, the number with an acute respiratory infection (ARI) during a 10-day postexposure period, and the number with ARI who tested positive for influenza by real-time reverse transcription PCR or serologic testing for each outbreak during December 15, 2014-March 31, 2015. During 60 outbreaks in 13 states, a total of 164 persons were exposed to infected birds. ARI developed in 5 of these persons within 10 days of exposure. H5 influenza virus infection was not identified in any persons with ARI, suggesting a low risk for animal-to-human HPAI H5 virus transmission. PMID:26583382

  9. Accumulation of functionally immature myeloid dendritic cells in lymph nodes of rhesus macaques with acute pathogenic simian immunodeficiency virus infection

    PubMed Central

    Wijewardana, Viskam; Bouwer, Anthea L; Brown, Kevin N; Liu, Xiangdong; Barratt-Boyes, Simon M

    2014-01-01

    Myeloid dendritic cells (mDC) are key mediators of innate and adaptive immunity to virus infection, but the impact of HIV infection on the mDC response, particularly early in acute infection, is ill-defined. We studied acute pathogenic simian immunodeficiency virus (SIV) infection of rhesus macaques to address this question. The mDC in blood and bone marrow were depleted within 12 days of intravenous infection with SIVmac251, associated with a marked proliferative response. In lymph nodes, mDC were apoptotic, activated and proliferating, despite normal mDC numbers, reflecting a regenerative response that compensated for mDC loss. Blood mDC had increased expression of MHC class II, CCR7 and CD40, whereas in lymph nodes these markers were significantly decreased, indicating that acute infection induced maturation of mDC in blood but resulted in accumulation of immature mDC in lymph nodes. Following SIV infection, lymph node mDC had an increased capacity to secrete tumour necrosis factor-α upon engagement with a Toll-like receptor 7/8 ligand that mimics exposure to viral RNA, and this was inversely correlated with MHC class II and CCR7 expression. Lymph node mDC had an increased ability to capture and cleave soluble antigen, confirming their functionally immature state. These data indicate that acute SIV infection results in increased mDC turnover, leading to accumulation in lymph nodes of immature mDC with an increased responsiveness to virus stimulation. PMID:24684292

  10. Experimental infection with low and high pathogenicity H7N3 Chilean avian influenza viruses in Chiloe Wigeon (Anas sibilatrix) and Cinnamon Teal (Anas cyanoptera)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since 2002, H5N1 high pathogenicity avian influenza (HPAI) viruses have been associated with natural, lethal infections in wild aquatic birds which have been reproduced experimentally. Some aquatic bird species have been suggested as potential transporters of H5N1 HPAI virus via migration. However, ...

  11. Impact of vaccination on infection with Vietnam H5N1 high pathogenicity avian influenza virus in hens and the eggs they lay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Highly pathogenic avian influenza virus (HPAIV) infections in chickens produce a negative impact on egg production, and virus is deposited on surface and internal contents of eggs. Previously, vaccination maintained egg production and reduced egg contamination when challenged with a North American H...

  12. Impact of porcine group A rotavirus co-infection on porcine epidemic diarrhea virus pathogenicity in piglets.

    PubMed

    Jung, Kwonil; Kang, Bo-Kyu; Lee, Chul-Seung; Song, Dae-Sub

    2008-06-01

    Porcine epidemic diarrhea virus (PEDV) and porcine group A rotavirus (PGAR) are the main causative agents of acute diarrhea in piglets. In South Korea, PGAR is prevalent in piglets naturally infected with PEDV. Piglets naturally co-infected with PEDV and PGAR appeared to have severe and prolonged diarrhea that was distinct from that commonly observed. The aim of this study was to determine the impact of PGAR co-infection on PEDV pathogenicity in piglets. Thirty-six colostrum-deprived, one-day old, Large White-Duroc crossbred pigs were randomly divided into four equal groups: PEDV, PEDV/PGAR, PGAR, and control groups. The piglets were euthanized at 1, 2, or 3 days post-inoculation (DPI) to measure the villous height:crypt depth (VH:CD) ratio and to collect fecal samples for RT-PCR and virus isolation. No significant differences in mean VH:CD ratio and clinical symptoms (diarrhea, vomiting, dehydration, and anorexia) were observed between the PEDV/PGAR-infected and PEDV-infected groups of piglets at 1, 2 and 3 DPI; however, at 2 and 3 DPI, PGAR was detected in all fecal samples by RT-PCR and virus isolation. These findings failed to detect any interaction between PEDV and porcine rotavirus in the small intestines of piglets, suggesting that concurrent infection of PGAR may not synergistically enhance intestinal villous atrophy of piglets with PEDV disease. We propose that the severe diarrhea exhibited in PEDV and PGAR co-infected piglets may be more associated with the immunity level of the host rather than to any synergistic effect of PGAR on PEDV enteritis. PMID:17727905

  13. Synergistic effects of sequential infection with highly pathogenic porcine reproductive and respiratory syndrome virus and porcine circovirus type 2

    PubMed Central

    2013-01-01

    Background Porcine reproductive and respiratory syndrome virus (PRRSV) is the causative agent of porcine reproductive and respiratory syndrome (PRRS) and porcine circovirus type 2 (PCV2) is associated with postweaning multisystemic wasting syndrome (PMWS) in pigs. Coinfection with highly pathogenic PRRSV (HP-PRRSV) and PCV2 in the field has recently become extensive in some Asian countries. A synergistic pathogenicity between PRRSV and PCV2 infections has previously been reported. However, the consequences of the sequential infection of pigs with these two viruses are unknown. Methods Thirty 35-day-old piglets were randomly divided into six groups (n = 5 each): HP-PRRSV/PCV2 (group 1, inoculated with HP-PRRSV, then inoculated with PCV2 one week later), PCV2/HP-PRRSV (group 2, inoculated with PCV2, then inoculated with HP-PRRSV one week later), HP-PRRSV+PCV2 (group 3, inoculated with HP-PRRSV and PCV2 concurrently), HP-PRRSV (group 4, inoculated with HP-PRRSV), PCV2 (group 5, inoculated with PCV2), and the control (group 6, uninfected). This experiment lasted 28 days. Clinical symptoms and rectal temperatures were recorded each day after inoculation, body weight was recorded weekly, and serum samples were obtained for viral nucleic acid quantification and antibody titration. Variations in CD3+, CD4+ CD8–, CD3+, CD4–, and CD8+ cells, natural killer (NK) cells, and mononuclear cells were determined by flow cytometry. The serum concentrations of interferon γ (IFN-γ), tumor necrosis factor α (TNF-α), interleukin 10 (IL-10), and macrophage granulocyte-colony stimulating factor (GM-CSF) were determined. Pathological changes in different tissues from the experimentally infected pigs were recorded. Results The piglets in group 1 had the highest viral loads, the lowest antibody titers, the most-severe clinical signs, and the highest mortality (3/5, 60%; the mortality in the other groups was 0%), and interstitial pneumonia was more severe in this group compare to the

  14. Experimental infection of mallard ducks with different subtype H5 and H7 highly pathogenic avian influenza viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Highly pathogenic avian influenza viruses (HPAIV’s) remain a threat to poultry worldwide. Avian influenza viruses, including HPAIV, are usually non-pathogenic for ducks and other wild aquatic birds, with the exception of some Asian lineage H5N1 HPAIVs which can cause severe disease in ducks. With ...

  15. Innate immune responses to infection with H5N1 highly pathogenic avian influenza virus in different duck species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ducks have been implicated in the dissemination and evolution of H5N1 highly pathogenic avian influenza (HPAI) viruses. Differences in pathogenicity and response to vaccination have been observed between different duck species. The innate immune system is responsible for controlling viruses during t...

  16. Infection of United States swine with a Chinese highly pathogenic strain of porcine reproductive and respiratory syndrome virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To assess the pathogenic effects of Type 2 highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) on healthy 10-week old commercial swine in the United States, viral kinetics and resultant disease caused by intranasal inoculation of such virus rescued from an infectious clo...

  17. Short-Term Heat Shock Affects Host–Virus Interaction in Mice Infected with Highly Pathogenic Avian Influenza Virus H5N1

    PubMed Central

    Xue, Jia; Fan, Xiaoxu; Yu, Jing; Zhang, Shouping; Xiao, Jin; Hu, Yanxin; Wang, Ming

    2016-01-01

    Highly pathogenic avian influenza virus (HPAIV) H5N1 is a highly contagious virus that can cause acute respiratory infections and high human fatality ratio due to excessive inflammatory response. Short-term heat shock, as a stressful condition, could induce the expression of heat shock proteins that function as molecular chaperones to protect cells against multiple stresses. However, the protective effect of short-term heat shock in influenza infection is far from being understood. In this study, mice were treated at 39°C for 4 h before being infected with HPAIV H5N1. Interestingly, short-term heat shock significantly increased the levels of HSP70 and pro-inflammatory cytokines IL-6, TNF-α, IFN-β, and IFN-γ in the lung tissues of mice. Following HPAIV H5N1 infection, short-term heat shock alleviated immunopathology and viral replication in lung tissue and repressed the weight loss and increased the survival rate of H5N1-infected mice. Our data reported that short-term heat shock provided beneficial anti-HPAIV H5N1 properties in mice model, which offers an alternative strategy for non-drug prevention for influenza infection. PMID:27379054

  18. Annual survival of ruddy turnstones is not affected by natural infection with low pathogenicity avian influenza viruses.

    PubMed

    Maxted, Angela M; Porter, Ronald R; Luttrell, M Page; Goekjian, Virginia H; Dey, Amanda D; Kalasz, Kevin S; Niles, Lawrence J; Stallknecht, David E

    2012-09-01

    The population of ruddy turnstones (Arenaria interpres morinella) that migrates through Delaware Bay has undergone severe declines in recent years, attributable to reduced availability of horseshoe crab (Limulus polyphemus) eggs at this critical spring migration stopover site. Concurrently, this population has experienced annual low pathogenicity avian influenza virus (AIV) epidemics at this same site. Using a prospective cohort study design with birds individually flagged during May-June 2006-2008, we evaluated resighting rates (a proxy for annual survival) between AIV-infected and uninfected birds at 1 yr after capture, testing, and measurement. Overall resighting rate was 46%, which varied by year and increased with relative mass of the bird when captured. Resighting rates were not different between AIV-infected and uninfected birds in any period. In multivariate analyses, infection status was also unrelated to resighting rate after controlling for year, day, state, sex, body size, mass index, or whether the bird was blood-sampled. Thus, apparent annual survival in ruddy turnstones was not reduced by AIV infection at this migratory stopover. However, it is unknown whether intestinal AIV infection might cause subtle reductions in weight gain which could negatively influence reproduction. PMID:23050475

  19. Detection of H5N1 high pathogenicity avian influenza virus in meat and tracheal samples from experimentally infected chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Asian H5N1 highly pathogenic avian influenza (HPAI) virus causes a systemic disease with high mortality of poultry and is potentially zoonotic. In both chickens and ducks, the virus has been demonstrated to replicate in both cardiac and skeletal muscle cells. Experimentally, H5N1 HPAI virus ha...

  20. Of Mice and Men: Protective and Pathogenic Immune Responses to West Nile virus Infection

    PubMed Central

    Trobaugh, Derek

    2015-01-01

    West Nile virus, a mosquito-borne flavivirus, first emerged in the Western Hemisphere in 1999. Although the majority of infections are asymptomatic, WNV causes significant morbidity and mortality in a minority of individuals who develop neuroinvasive disease, in particular the elderly and immunocompromised. Research in animal models has demonstrated interactions between WNV and the innate and adaptive immune system, some of which protect the host and others which are deleterious. Studies of disease pathogenesis in humans are less numerous, largely due to the complexities of WNV epidemiology. Human studies that have been done support the notion that innate and adaptive immune responses are delicately balanced and may help or harm the host. Further human investigations are needed to characterize beneficial responses to WNV with the goal of such research leading to therapeutics and effective vaccines in order to control this emerging viral disease. PMID:26120511

  1. Human infection with a highly pathogenic avian influenza A (H5N6) virus in Yunnan province, China.

    PubMed

    Xu, Wen; Li, Hong; Jiang, Li

    2016-01-01

    Highly pathogenic avian influenza A H5N6 virus has caused four human infections in China. This study reports the preliminary findings of the first known human case of H5N6 in Yunnan province. The patient initially developed symptoms of sore throat and coughing on 27 January 2015. The disease rapidly progressed to severe pneumonia, multiple organ dysfunctions and acute respiratory distress syndrome and the patient died on 6 February. Virological analysis determined that the virus belonged to H5 clade 2.3.4.4 and it has obtained partial ability for mammalian adaptation and amantadine resistance. Environmental investigation found H5 in 63% of the samples including poultry faeces, tissues, cage surface swabs and sewage from local live poultry markets by real-time RT-PCR. These findings suggest that the expanding and enhancing of surveillance in both avian and humans are necessary to monitor the evolution of H5 influenza virus and to facilitate early detection of suspected cases. PMID:27030920

  2. Human Influenza Virus Infections.

    PubMed

    Peteranderl, Christin; Herold, Susanne; Schmoldt, Carole

    2016-08-01

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

  3. Analysis of the crow lung transcriptome in response to infection with highly pathogenic H5N1 avian influenza virus.

    PubMed

    Vijayakumar, Periyasamy; Mishra, Anamika; Ranaware, Pradip B; Kolte, Atul P; Kulkarni, Diwakar D; Burt, David W; Raut, Ashwin Ashok

    2015-03-15

    The highly pathogenic avian influenza (HPAI) H5N1 virus, currently circulating in Asia, causes severe disease in domestic poultry as well as wild birds like crow. However, the molecular pathogenesis of HPAIV infection in crows and other wild birds is not well known. Thus, as a step to explore it, a comprehensive global gene expression analysis was performed on crow lungs, infected with HPAI H5N1 crow isolate (A/Crow/India/11TI11/2011) using high throughput next generation sequencing (NGS) (GS FLX Titanium XLR70). The reference genome of crow is not available, so RNA seq analysis was performed on the basis of a de novo assembled transcriptome. The RNA seq result shows, 4052 genes were expressed uniquely in noninfected, 6277 genes were expressed uniquely in HPAIV infected sample and of the 6814 genes expressed in both samples, 2279 genes were significantly differentially expressed. Our transcriptome profile data allows for the ability to understand the molecular mechanism behind the recent lethal HPAIV outbreak in crows which was, until recently, thought to cause lethal infections only in gallinaceous birds such as chickens, but not in wild birds. The pattern of differentially expressed genes suggest that this isolate of H5N1 virus evades the host innate immune response by attenuating interferon (IFN)-inducible signalling possibly by down regulating the signalling from type I IFN (IFNAR1 and IFNAR2) and type II IFN receptors, upregulation of the signalling inhibitors suppressor of cytokine signalling 1 (SOCS1) and SOCS3 and altering the expression of toll-like receptors (TLRs). This may be the reason for disease and mortality in crows. PMID:25592823

  4. Long-Term Effect of Serial Infections with H13 and H16 Low-Pathogenic Avian Influenza Viruses in Black-Headed Gulls

    PubMed Central

    Verhagen, Josanne H.; van Amerongen, Geert; van de Bildt, Marco; Majoor, Frank; Fouchier, Ron A. M.

    2015-01-01

    ABSTRACT Infections of domestic and wild birds with low-pathogenic avian influenza viruses (LPAIVs) have been associated with protective immunity to subsequent infection. However, the degree and duration of immunity in wild birds from previous LPAIV infection, by the same or a different subtype, are poorly understood. Therefore, we inoculated H13N2 (A/black-headed gull/Netherlands/7/2009) and H16N3 (A/black-headed gull/Netherlands/26/2009) LPAIVs into black-headed gulls (Chroicocephalus ridibundus), their natural host species, and measured the long-term immune response and protection against one or two reinfections over a period of >1 year. This is the typical interval between LPAIV epizootics in wild birds. Reinfection with the same virus resulted in progressively less virus excretion, with complete abrogation of virus excretion after two infections for H13 but not H16. However, reinfection with the other virus affected neither the level nor duration of virus excretion. Virus excretion by immunologically naive birds did not differ in total levels of excreted H13 or H16 virus between first- and second-year birds, but the duration of H13 excretion was shorter for second-year birds. Furthermore, serum antibody levels did not correlate with protection against LPAIV infection. LPAIV-infected gulls showed no clinical signs of disease. These results imply that the epidemiological cycles of H13 and H16 in black-headed gulls are relatively independent from each other and depend mainly on infection of first-year birds. IMPORTANCE Low-pathogenic avian influenza viruses (LPAIVs) circulate mainly in wild water birds but are occasionally transmitted to other species, including humans, where they cause subclinical to fatal disease. To date, the effect of LPAIV-specific immunity on the epidemiology of LPAIV in wild birds is poorly understood. In this study, we investigated the effect of H13 and H16 LPAIV infection in black-headed gulls on susceptibility and virus excretion of

  5. Impact of vaccination on infection with Vietnam H5N1 high pathogenicity avian influenza virus in hens and the eggs they lay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High pathogenicity avian influenza virus (HPAIV) infections in chickens decrease egg production and eggs that are laid contain HPAIV. Vaccination once or twice was examined as a way to protect chickens from Vietnamese H5N1 HPAIV. Eighty-three percent of hens without vaccination died within 3 days ...

  6. Effect of homosubtypic and heterosubtypic low pathogenic avian influenza exposure on H5N1 highly pathogenic avian influenza virus infection in wood ducks (Aix sponsa)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wild birds in the Orders Anseriformes and Charadriiformes are the natural reservoirs for avian influenza (AI) viruses. Although they are often infected with multiple AI viruses, the significance and extent of acquired immunity in these populations is not understood. Pre-existing immunity to AI virus...

  7. Viral Small-RNA Analysis of Bombyx mori Larval Midgut during Persistent and Pathogenic Cytoplasmic Polyhedrosis Virus Infection

    PubMed Central

    Van Nieuwerburgh, Filip; Kolliopoulou, Anna; Apostolou-Karampelis, Konstantinos; Head, Steven R.; Deforce, Dieter; Smagghe, Guy; Swevers, Luc

    2015-01-01

    ABSTRACT The lepidopteran innate immune response against RNA viruses remains poorly understood, while in other insects several studies have highlighted an essential role for the exo-RNAi pathway in combating viral infection. Here, by using deep-sequencing technology for viral small-RNA (vsRNA) assessment, we provide evidence that exo-RNAi is operative in the silkworm Bombyx mori against both persistent and pathogenic infection of B. mori cytoplasmic polyhedrosis virus (BmCPV) which is characterized by a segmented double-stranded RNA (dsRNA) genome. Further, we show that Dicer-2 predominantly targets viral dsRNA and produces 20-nucleotide (nt) vsRNAs, whereas an additional pathway is responsive to viral mRNA derived from segment 10. Importantly, vsRNA distributions, which define specific hot and cold spot profiles for each viral segment, to a considerable degree overlap between Dicer-2-related (19 to 21 nt) and Dicer-2-unrelated vsRNAs, suggesting a common origin for these profiles. We found a degenerate motif significantly enriched at the cut sites of vsRNAs of various lengths which link an unknown RNase to the origins of vsRNAs biogenesis and distribution. Accordingly, the indicated RNase activity may be an important early factor for the host's antiviral defense in Lepidoptera. IMPORTANCE This work contributes to the elucidation of the lepidopteran antiviral response against infection of segmented double-stranded RNA (dsRNA) virus (CPV; Reoviridae) and highlights the importance of viral small-RNA (vsRNA) analysis for getting insights into host-pathogen interactions. Three vsRNA pathways are implicated in antiviral defense. For dsRNA, two pathways are proposed, either based on Dicer-2 cleavage to generate 20-nucleotide vsRNAs or based on the activity of an uncharacterized endo-RNase that cleaves the viral RNA substrate at a degenerate motif. The analysis also indicates the existence of a degradation pathway that targets the positive strand of segment 10. PMID

  8. Susceptibility of selected wild avian species to experimental infection with H5N1 high pathogenicity avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since 2002, H5N1 highly pathogenic avian influenza (HPAI) viruses have caused mortality in wide diversity of wild avian species but, to date, the role that different species play in the transmission and maintenance of H5N1 HPAI viruses is poorly understood. To begin to address these uncertainties a...

  9. Experimental infection with low and high pathogenicity H7N3 Chilean avian influenza viruses in Chiloe wigeon (Anas sibilatrix) and cinnamon teal (Anas cyanoptera).

    PubMed

    Sá e Silva, Mariana; Mathieu-Benson, Christian; Kwon, Yong-Kuk; Pantin-Jackwood, Mary; Swayne, David E

    2011-09-01

    Two different wild duck species common in Chile and neighboring countries, Chiloe wigeon (Anas sibilatrix) and cinnamon teal (Anas cyanoptera), were intranasally inoculated with 10(6) mean embryo infective dose (EID50) of the H7N3 low pathogenicity (LP) avian influenza virus (AIV) (A/chicken/Chile/176822/02) or high pathogenicity (HP) AIV (A/chicken/Chile/ 184240-1/02), in order to study the infectivity and pathobiology of these viruses. None of the virus-inoculated ducks had clinical signs or died, but most seroconverted by 14 days postinoculation (DPI), indicating a productive virus infection. Both LPAIV and HPAIV were isolated from oral swabs from two of six Chiloe wigeons and from oral and/or cloacal swabs from all five of the cinnamon teal at 2 DPI. Both LPAIV and HPAIV were efficiently transmitted to cinnamon teal contacts but not to Chiloe wigeon contacts. This study demonstrates that the cinnamon teal and Chiloe wigeons were susceptible to infection with both Chilean H7N3 LPAIV and HPAIV, but only the cinnamon teal showed contact transmission of the virus between birds, suggesting that the cinnamon teal has the potential to be a reservoir for these viruses, especially the LPAIV, as was demonstrated in 2001 with isolation of a genetically related H7N3 LPAIV strain in a cinnamon teal in Bolivia. However, the definitive source of the H7N3 Chilean LPAIV still remains unknown. PMID:22017047

  10. Experimental co-infection of chickens with lentogenic, mesogenic and velogenic strains of Newcastle disease viruses and highly pathogenic avian influenza viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  11. Host antiviral defenses induced by 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. To evaluate the dynamics of AIV-NDV co-i...

  12. Early events in tissues during infection with pathogenic (SIVmac239) and nonpathogenic (SIVmac1A11) molecular clones of simian immunodeficiency virus.

    PubMed Central

    Lackner, A. A.; Vogel, P.; Ramos, R. A.; Kluge, J. D.; Marthas, M.

    1994-01-01

    The extent of virus replication, tissue distribution, localization of virus within tissues, and the presence of pathological lesions was examined early after experimental infection of rhesus monkeys with simian immunodeficiency virus (SIV). Three strains of SIV were used: molecularly cloned pathogenic SIVmac239; molecularly cloned nonpathogenic SIVmac1A11; and uncloned pathogenic SIVmac. The major targets of infection in all animals at 2 weeks postinoculation were the thymus and spleen. The distribution of virus within lymphoid organs varied with the viral inoculum: nonpathogenic SIVmac1A11 was present primarily within lymphoid follicles and in the thymic cortex; SIVmac239 was present primarily within periarteriolar lymphoid sheaths in the spleen, the paracortex of lymph nodes, and the medulla of the thymus; uncloned SIVmac was present in all these areas but tended to parallel the distribution of SIVmac239. Animals inoculated with nonpathogenic SIVmac1A11 had fewer SIV-positive cells by in situ hybridization and after 13 weeks postinoculation, virus was undetectable in any tissue from these animals. No significant pathological abnormalities were recognized in animals inoculated with this nonpathogenic virus. In contrast, nearly half of the animals inoculated with either SIVmac or SIVmac239 developed significant pathological lesions, including opportunistic infections by 13 weeks postinoculation, highlighting the virulence of these viruses. Our results indicate marked differences in tissue distribution between pathogenic and nonpathogenic molecular clones of SIV during the acute phase of infection. The most striking differences were the absence of SIVmac1A11 from the central nervous system and thymic medulla. The prominent early involvement of the thymus suggests that infection of this organ is a key event in the induction of immune suppression by SIV. Images Figure 1 Figure 2 Figure 3 PMID:8053500

  13. Transcription factor regulation and cytokine expression following in vitro infection of primary chicken cell culture with low pathogenic avian influenza virus

    PubMed Central

    2013-01-01

    Background Avian influenza virus (AIV) induced proinflammatory cytokine expression is believed to contribute to the disease pathogenesis following infection of poultry. However, there is limited information on the avian immune response to infection with low pathogenic avian influenza virus (LPAIV). Methods To gain a better understanding of the early viral-host interactions of LPAIV in chickens, primary chicken embryo hepatocytes (CEH) were infected with four different LPAIVs of U.S. origin. Kinetics of virus replication, transcription factor (c-Jun, p50 and IRF-3) activation and immune response gene (IL-6, IL-1beta, IFN-alpha and Mx) expression were studied at four different time points (6, 12, 24 and 48 hours) post infection and compared to non-infected controls. Results CEH can support growth of the tested LPAIVs when with trypsin supplementation. All four immune response genes tested were upregulated following infection as were transcription factors c-Jun, p50 and IRF-3. Amplification of these genes was dependant on virus replication (e.g. inclusion of trypsin), such that immune response genes and transcription factors were upregulated as viral titers increased. Conclusion The results of these studies demonstrate the requirement of virus replication for innate immune regulation and broaden our understanding of transcription factor responses related to LPAIV infection in chickens. PMID:24252391

  14. Experimental infection of United States swine with a Chinese highly pathogenic strain of porcine reproductive and respiratory syndrome virus.

    PubMed

    Guo, Baoqing; Lager, Kelly M; Henningson, Jamie N; Miller, Laura C; Schlink, Sarah N; Kappes, Matthew A; Kehrli, Marcus E; Brockmeier, Susan L; Nicholson, Tracy L; Yang, Han-Chun; Faaberg, Kay S

    2013-01-20

    The pathogenesis of Type 2 highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) in 10-week old swine in the United States was investigated. rJXwn06, rescued from an infectious clone of Chinese HP-PRRSV, replicated in swine with at least 100-fold increased kinetics over U.S. strain VR-2332. rJXwn06 caused significant weight loss, exacerbated disease due to bacterial sepsis and more severe histopathological lung lesions in pigs exposed to HP-PRRSV than to those infected with VR-2332. Novel findings include identification of bacterial species present, the degree of thymic atrophy seen, and the inclusion of contact animals that highlighted the ability of HP-PRRSV to rapidly transmit between animals. Furthermore, comprehensive detailed cytokine analysis of serum, bronchoalveolar lavage fluid, and tracheobronchial lymph node tissue homogenate revealed a striking elevation in levels of cytokines associated with both innate and adaptive immunity in HP-PRRSV infected swine, and showed that contact swine differed in the degree of cytokine response. PMID:23079105

  15. Disease Severity Is Associated with Differential Gene Expression at the Early and Late Phases of Infection in Nonhuman Primates Infected with Different H5N1 Highly Pathogenic Avian Influenza Viruses

    PubMed Central

    Muramoto, Yukiko; Shoemaker, Jason E.; Le, Mai Quynh; Itoh, Yasushi; Tamura, Daisuke; Sakai-Tagawa, Yuko; Imai, Hirotaka; Uraki, Ryuta; Takano, Ryo; Kawakami, Eiryo; Ito, Mutsumi; Okamoto, Kiyoko; Ishigaki, Hirohito; Mimuro, Hitomi; Sasakawa, Chihiro; Matsuoka, Yukiko; Noda, Takeshi; Fukuyama, Satoshi; Ogasawara, Kazumasa; Kitano, Hiroaki

    2014-01-01

    ABSTRACT Occasional transmission of highly pathogenic avian H5N1 influenza viruses to humans causes severe pneumonia with high mortality. To better understand the mechanisms via which H5N1 viruses induce severe disease in humans, we infected cynomolgus macaques with six different H5N1 strains isolated from human patients and compared their pathogenicity and the global host responses to the virus infection. Although all H5N1 viruses replicated in the respiratory tract, there was substantial heterogeneity in their replicative ability and in the disease severity induced, which ranged from asymptomatic to fatal. A comparison of global gene expression between severe and mild disease cases indicated that interferon-induced upregulation of genes related to innate immunity, apoptosis, and antigen processing/presentation in the early phase of infection was limited in severe disease cases, although interferon expression was upregulated in both severe and mild cases. Furthermore, coexpression analysis of microarray data, which reveals the dynamics of host responses during the infection, demonstrated that the limited expression of these genes early in infection led to a failure to suppress virus replication and to the hyperinduction of genes related to immunity, inflammation, coagulation, and homeostasis in the late phase of infection, resulting in a more severe disease. Our data suggest that the attenuated interferon-induced activation of innate immunity, apoptosis, and antigen presentation in the early phase of H5N1 virus infection leads to subsequent severe disease outcome. IMPORTANCE Highly pathogenic avian H5N1 influenza viruses sometimes transmit to humans and cause severe pneumonia with ca. 60% lethality. The continued circulation of these viruses poses a pandemic threat; however, their pathogenesis in mammals is not fully understood. We, therefore, investigated the pathogenicity of six H5N1 viruses and compared the host responses of cynomolgus macaques to the virus

  16. Pathogenesis and transmissibility of highly (H7N1) and low (H7N9) pathogenic avian influenza virus infection in red-legged partridge (Alectoris rufa)

    PubMed Central

    2011-01-01

    An experimental infection with highly pathogenic avian influenza virus (HPAIV) and low pathogenic avian influenza virus (LPAIV) was carried out in red-legged partridges (Alectoris rufa) in order to study clinical signs, gross and microscopic lesions, and viral distribution in tissues and viral shedding. Birds were infected with a HPAIV subtype H7N1 (A/Chicken/Italy/5093/1999) and a LPAIV subtype H7N9 (A/Anas crecca/Spain/1460/2008). Uninoculated birds were included as contacts in both groups. In HPAIV infected birds, the first clinical signs were observed at 3 dpi, and mortality started at 4 dpi, reaching 100% at 8 dpi. The presence of viral antigen in tissues and viral shedding were confirmed by immunohistochemistry and quantitative real time RT-PCR (qRRT-PCR), respectively, in all birds infected with HPAIV. However, neither clinical signs nor histopathological findings were observed in LPAIV infected partridges. In addition, only short-term viral shedding together with seroconversion was detected in some LPAIV inoculated animals. The present study demonstrates that the red-legged partridge is highly susceptible to the H7N1 HPAIV strain, causing severe disease, mortality and abundant viral shedding and thus contributing to the spread of a potential local outbreak of this virus. In contrast, our results concerning H7N9 LPAIV suggest that the red-legged partridge is not a reservoir species for this virus. PMID:21314907

  17. Infected or not: are PCR-positive oropharyngeal swabs indicative of low pathogenic influenza A virus infection in the respiratory tract of Mallard Anas platyrhynchos?

    PubMed

    Wille, Michelle; van Run, Peter; Waldenström, Jonas; Kuiken, Thijs

    2014-01-01

    Detection of influenza virus in oropharyngeal swabs collected during wild bird surveillance is assumed to represent respiratory infection, although intestine is the main site of infection. We tested this assumption by histological examination of the respiratory tract of wild Mallards with virus-positive oropharyngeal swabs. Thirty-two of 125 Mallards tested had viral-RNA positive oropharyngeal swabs. The respiratory tracts of four Mallards with the most virus were examined in detail by immunohistochemistry. None had detectable virus antigen in the respiratory tract, suggesting it was not infected. An alternative explanation is that the oropharynx was contaminated with virus through feeding in surface water or through preening. PMID:24885647

  18. Molecular Signatures Associated with Mx1-Mediated Resistance to Highly Pathogenic Influenza Virus Infection: Mechanisms of Survival

    PubMed Central

    Cilloniz, Cristian; Pantin-Jackwood, Mary J.; Ni, Chester; Carter, Victoria S.; Korth, Marcus J.; Swayne, David E.; Tumpey, Terrence M.

    2012-01-01

    Understanding the role of host factors during lethal influenza virus infection is critical to deciphering the events that determine the fate of the host. One such factor is encoded by the Mx1 gene, which confers resistance to influenza virus infection. Here, we compared pathology and global gene expression profiles in lung tissue from BALB/c (Mx1−) and BALB · A2G-Mx1 mice (Mx1+/+) infected with the fully reconstructed 1918 pandemic influenza virus. Mx1+/+ mice showed less tissue damage than Mx− animals, and pathology and mortality were further reduced by treating the mice with interferon prior to infection. Using global transcriptional profiling, we identified distinct molecular signatures associated with partial protection, complete protection, and the contribution of interferon to the host response. In the absence of interferon treatment, partial protection was characterized by the generation of an acute response with the upregulation of genes associated with apoptosis, reactive oxygen species, and cell migration. Complete protection was characterized by the downregulation of cytokine and chemokine genes previously associated with influenza virus pathogenesis. The contribution of interferon treatment to total protection in virus-infected Mx1+/+ mice was characterized by the altered regulation of cell cycle genes. These genes were upregulated in Mx1+/+ mice treated with interferon but downregulated in the absence of interferon treatment. Our results suggest that Mx1+/+ mice generate a protective antiviral response by controlling the expression of key modulator molecules associated with influenza virus lethality. PMID:22190720

  19. Differences in pathogenicity and response to vaccination between Pekin and Muscovy ducks infected with H5N1 highly pathogenic influenza viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ducks have been implicated in the dissemination and evolution of H5N1 highly pathogenic avian influenza (HPAI) viruses. Vaccination of domestic ducks against H5N1 HPAI is being conducted as a method of control but with mixed results. One of the observations from the field is that Muscovy ducks (Cair...

  20. Experimental infection of bar-headed geese (Anser indicus) and ruddy shelducks (Tadorna ferruginea) with a clade 2.3.2 H5N1 highly pathogenic avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since 2005, clade 2.2 H5N1 highly pathogenic avian influenza (HPAI) viruses have caused infections and disease involving numerous species of wild waterfowl in Eurasia and Africa. However, outbreaks associated with clade 2.3.2 viruses have increased since 2009, and viruses within this clade have beco...

  1. Highly Pathogenic Simian Immunodeficiency Virus mne Variants That Emerge during the Course of Infection Evolve Enhanced Infectivity and the Ability To Downregulate CD4 but Not Class I Major Histocompatibility Complex Antigens

    PubMed Central

    Patel, Parul G.; Yu Kimata, Monica T.; Biggins, Julia E.; Wilson, Joelle M.; Kimata, Jason T.

    2002-01-01

    The replicative, cytopathic, and antigenic properties of simian immunodeficiency virus (SIV) variants influence its replication efficiency in vivo. To further define the viral properties and determinants that may be important for high-level replication in vivo and progression to AIDS, we compared a minimally pathogenic SIVmne molecular clone with two highly pathogenic variants cloned from late stages of infection. Both variants had evolved greater infectivity than the parental clone due to mutations in nef. Interestingly, a pol determinant in one of the highly pathogenic variants also contributed to its increased infectivity. Furthermore, because replication in vivo may also be influenced by the ability of a virus to evade the cellular immune response of the host, we examined whether the variants were more capable of downregulating surface expression of class I major histocompatibility complex (MHC). Decreased MHC class I expression was not observed in cells infected with any of the viruses. Furthermore, the Nef proteins of the highly pathogenic variants only slightly reduced surface MHC class I expression in transfected cells, although they efficiently downregulated CD4. Together, these data demonstrate that mutations which can enhance viral infectivity, as well as CD4 downregulation, may be important for efficient replication of SIV in the host. However, Nef-mediated reduction of MHC class I expression does not appear to be critical for the increased in vivo replicative ability of highly pathogenic late variants. PMID:12050354

  2. Pathogenic Pseudorabies Virus, China, 2012

    PubMed Central

    Yu, Xiuling; Zhou, Zhi; Hu, Dongmei; Zhang, Qian; Han, Tao; Li, Xiaoxia; Gu, Xiaoxue; Yuan, Lin; Zhang, Shuo; Wang, Baoyue; Qu, Ping; Liu, Jinhua; Zhai, Xinyan

    2014-01-01

    In 2012, an unprecedented large-scale outbreak of disease in pigs in China caused great economic losses to the swine industry. Isolates from pseudorabies virus epidemics in swine herds were characterized. Evidence confirmed that the pathogenic pseudorabies virus was the etiologic agent of this epidemic. PMID:24377462

  3. West Nile Virus Infection.

    PubMed

    Sejvar, James J

    2016-06-01

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

  4. Metagenomic Detection of Viral Pathogens in Spanish Honeybees: Co-Infection by Aphid Lethal Paralysis, Israel Acute Paralysis and Lake Sinai Viruses

    PubMed Central

    Rubio-Guerri, Consuelo; Karlsson, Oskar E.; Kukielka, Deborah; Belák, Sándor; Sánchez-Vizcaíno, José Manuel

    2013-01-01

    The situation in Europe concerning honeybees has in recent years become increasingly aggravated with steady decline in populations and/or catastrophic winter losses. This has largely been attributed to the occurrence of a variety of known and “unknown”, emerging novel diseases. Previous studies have demonstrated that colonies often can harbour more than one pathogen, making identification of etiological agents with classical methods difficult. By employing an unbiased metagenomic approach, which allows the detection of both unexpected and previously unknown infectious agents, the detection of three viruses, Aphid Lethal Paralysis Virus (ALPV), Israel Acute Paralysis Virus (IAPV), and Lake Sinai Virus (LSV), in honeybees from Spain is reported in this article. The existence of a subgroup of ALPV with the ability to infect bees was only recently reported and this is the first identification of such a strain in Europe. Similarly, LSV appear to be a still unclassified group of viruses with unclear impact on colony health and these viruses have not previously been identified outside of the United States. Furthermore, our study also reveals that these bees carried a plant virus, Turnip Ringspot Virus (TuRSV), potentially serving as important vector organisms. Taken together, these results demonstrate the new possibilities opened up by high-throughput sequencing and metagenomic analysis to study emerging new diseases in domestic and wild animal populations, including honeybees. PMID:23460860

  5. Experimental infection of highly and low pathogenic avian influenza viruses to chickens, ducks, tree sparrows, jungle crows, and black rats for the evaluation of their roles in virus transmission.

    PubMed

    Hiono, Takahiro; Okamatsu, Masatoshi; Yamamoto, Naoki; Ogasawara, Kohei; Endo, Mayumi; Kuribayashi, Saya; Shichinohe, Shintaro; Motohashi, Yurie; Chu, Duc-Huy; Suzuki, Mizuho; Ichikawa, Takaya; Nishi, Tatsuya; Abe, Yuri; Matsuno, Keita; Tanaka, Kazuyuki; Tanigawa, Tsutomu; Kida, Hiroshi; Sakoda, Yoshihiro

    2016-01-15

    Highly pathogenic avian influenza viruses (HPAIVs) have spread in both poultry and wild birds. Determining transmission routes of these viruses during an outbreak is essential for the control of avian influenza. It has been widely postulated that migratory ducks play crucial roles in the widespread dissemination of HPAIVs in poultry by carrying viruses along with their migrations; however close contacts between wild migratory ducks and poultry are less likely in modern industrial poultry farming settings. Therefore, we conducted experimental infections of HPAIVs and low pathogenic avian influenza viruses (LPAIVs) to chickens, domestic ducks, tree sparrows, jungle crows, and black rats to evaluate their roles in virus transmission. The results showed that chickens, ducks, sparrows, and crows were highly susceptible to HPAIV infection. Significant titers of virus were recovered from the sparrows and crows infected with HPAIVs, which suggests that they potentially play roles of transmission of HPAIVs to poultry. In contrast, the growth of LPAIVs was limited in each of the animals tested compared with that of HPAIVs. The present results indicate that these common synanthropes play some roles in influenza virus transmission from wild birds to poultry. PMID:26711036

  6. Pathogenicity of an H5N1 avian influenza virus isolated in Vietnam in 2012 and reliability of conjunctival samples for diagnosis of infection

    PubMed Central

    Bui, Vuong N.; Dao, Tung D.; Nguyen, Tham T. H.; Nguyen, Lien T.; Bui, Anh N.; Trinh, Dai Q.; Pham, Nga T.; Inui, Kenjiro; Runstadler, Jonathan; Ogawa, Haruko; Nguyen, Khong V.; Imai, Kunitoshi

    2013-01-01

    The continued spread of highly pathogenic avian influenza virus (HPAIV) subtype H5N1 among poultry in Vietnam poses a potential threat to animals and public health. To evaluate the pathogenicity of a 2012 H5N1 HPAIV isolate and to assess the utility of conjunctival swabs for viral detection and isolation in surveillance, an experimental infection with HPAIV subtype H5N1 was carried out in domestic ducks. Ducks were infected with 107.2 TCID50 of A/duck/Vietnam/QB1207/2012 (H5N1), which was isolated from a moribund domestic duck. In the infected ducks, clinical signs of disease, including neurological disorder, were observed. Ducks started to die at 3 days-post-infection (dpi), and the study mortality reached 67%. Viruses were recovered from oropharyngeal and conjunctival swabs until 7 dpi and from cloacal swabs until 4 dpi. In the ducks that died or were sacrificed on 3, 5, or 6 dpi, viruses were recovered from lung, brain, heart, pancreas and intestine, among which the highest virus titers were in the lung, brain or heart. Results of virus titration were confirmed by real-time RT-PCR. Genetic and phylogenetic analysis of the HA gene revealed that the isolate belongs to clade 2.3.2.1 similarly to the H5N1 viruses isolated in Vietnam in 2012. The present study demonstrated that this recent HPAI H5N1 virus of clade 2.3.2.1 could replicate efficiently in the systemic organs, including the brain, and cause severe disease with neurological symptoms in domestic ducks. Therefore, this HPAI H5N1 virus seems to retain the neurotrophic feature and has further developed properties of shedding virus from the oropharynx and conjunctiva in addition to the cloaca, potentially posing a higher risk of virus spread through cross-contact and/or environmental transmission. Continued surveillance and diagnostic programs using conjuntcival swabs in the field would further verify the apparent reliability of conjunctival samples for the detection of AIV. PMID:24211664

  7. Histopathologic Characterization and Shedding Dynamics of Guineafowl (Numida meleagris) Intravenously Infected with a H6N2 Low Pathogenicity Avian Influenza Virus.

    PubMed

    Dimitrov, Kiril M; Zarkov, Ivan S; Dinev, Ivan; Goujgoulova, Gabriela V; Miller, Patti J; Suarez, David L

    2016-05-01

    Guineafowl of different ages were inoculated intravenously with a H6N2 wild waterfowl-origin low pathogenicity avian influenza virus (LPAIV). No clinical disease was observed. The infected birds had atrophy of the spleen, thymus, and cloacal bursa when compared with the noninfected control groups. The central and peripheral lymphoid tissues presented either lymphoproliferative or degenerative lesions that increased in intensity from 14 to 21 days postinoculation (DPI). Lymphoid depletion was present in the bursa, thymic lobes, and spleen T-dependent zone. In contrast, lymphoid proliferation was observed in liver, pancreas, and spleen B-dependent zone. Bronchus associated lymphoid tissue hyperplasia was observed in the lungs of the birds at 14 and 21 DPI. The virus was detected by virus isolation and reverse transcription PCR from both oropharyngeal and cloacal swabs with higher isolation rates from the latter. Most birds from the LPAIV inoculated groups shed virus up to 7 DPI. The virus was infrequently isolated from lung, kidney, liver, bursa, or spleen of infected birds until 14 DPI and from two samples (kidney and spleen, 1-yr-old birds) at 21 DPI. These data indicate that the wild bird-origin LPAIV used in this study caused pantropic infection in guineafowl when inoculated intravenously. PMID:27309068

  8. The effect of age on the pathogenesis of a highly pathogenic avian influenza (HPAI) H5N1 virus in Pekin ducks (Anas platyrhynchos) infected experimentally

    PubMed Central

    Löndt, Brandon Z.; Núñez, Alejandro.; Banks, Jill; Alexander, Dennis J.; Russell, Christine; Richard‐ Löndt, Angela C.; Brown, Ian H.

    2009-01-01

    Background  Highly pathogenic avian influenza (HPAI) H5N1 viruses have recently displayed increased virulence for wild waterfowl. Objectives  To study the effect of host age on the shedding and tissue dissemination of a HPAI H5N1 virus in infected Pekin ducks. Methods  Pekin ducks in two age‐matched groups (n = 18), 8 and 12 weeks old (wo) were each infected with 106 EID50/0·1 ml of HPAI A/turkey/Turkey/1/05 (H5N1, clade 2·2). Each day for 5 days, birds were monitored clinically, and cloacal and oropharyngeal swabs collected, before three birds from each group were selected randomly for post‐mortem examination. Tissue samples were collected for examination by real‐time RT‐PCR, histopathology and immunohistochemistry (IHC). Results  Severe clinical signs, including incoordination and torticollis were observed in the 8 wo group resulting in 100% mortality by 4 dpi. Mild clinical signs were observed in the 12 wo group with no mortality. Real‐time RT‐PCR and IHC results demonstrated the systemic spread of H5N1 virus in birds of both age groups. Higher levels of virus shedding were detected in oropharyngeal swabs than in cloacal swabs, with similar levels of shedding detected in both age groups. Variations in level and temporal dissemination of virus within tissues of older ducks, and the presence of the virus in brain and heart were observed, which coincided with the appearance of clinical signs preceding death in younger birds. Conclusions  These results are consistent with reports of natural infections of wild waterfowl and poultry possibly indicating an age‐related association with dissemination and clinical outcome in ducks following infection with H5N1 HPAI virus. PMID:20021503

  9. The Detection of a Low Pathogenicity Avian Influenza Virus Subtype H9 Infection in a Turkey Breeder Flock in the United Kingdom.

    PubMed

    Reid, Scott M; Banks, Jill; Ceeraz, Vanessa; Seekings, Amanda; Howard, Wendy A; Puranik, Anita; Collins, Susan; Manvell, Ruth; Irvine, Richard M; Brown, Ian H

    2016-05-01

    In April 2013, an H9N2 low pathogenicity avian influenza (LPAI) virus was isolated in a turkey breeder farm in Eastern England comprising 4966 birds. Point-of-lay turkey breeding birds had been moved from a rearing site and within 5 days had shown rapid onset of clinical signs of dullness, coughing, and anorexia. Three houses were involved, two contained a total of 4727 turkey hens, and the third housed 239 male turkeys. Around 50% of the hens were affected, whereas the male turkeys demonstrated milder clinical signs. Bird morbidity rose from 10% to 90%, with an increase in mortality in both houses of turkey hens to 17 dead birds in one house and 27 birds in the second house by day 6. The birds were treated with an antibiotic but were not responsive. Postmortem investigation revealed air sacculitis but no infraorbital sinus swellings or sinusitis. Standard samples were collected, and influenza A was detected. H9 virus infection was confirmed in all three houses by detection and subtyping of hemagglutinating agents in embryonated specific-pathogen-free fowls' eggs, which were shown to be viruses of H9N2 subtype using neuraminidase inhibition tests and a suite of real-time reverse transcription PCR assays. LPAI virus pathotype was suggested by cleavage site sequencing, and an intravenous pathogenicity index of 0.00 confirmed that the virus was of low pathogenicity. Therefore, no official disease control measures were required, and despite the high morbidity, birds recovered and were kept in production. Neuraminidase sequence analysis revealed a deletion of 78 nucleotides in the stalk region, suggesting an adaptation of the virus to poultry. Hemagglutinin gene sequences of two of the isolates clustered with a group of H9 viruses containing other contemporary European H9 strains in the Y439/Korean-like group. The closest matches to the two isolates were A/turkey/Netherlands/11015452/11 (H9N2; 97.9-98% nucleotide identity) and A/mallard/Finland/Li13384/10 (H9N2; 97

  10. 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

  11. The critical time of avian leukosis virus subgroup J-mediated immunosuppression during early stage infection in specific pathogen-free chickens.

    PubMed

    Wang, Feng; Wang, Xiaowei; Chen, Hongbo; Liu, Jianzhu; Cheng, Ziqiang

    2011-09-01

    The critical time of avian leukosis virus subgroup J (ALV-J)-mediated immunosuppression was determined by body weight, relative immune organ weight, histopathology, and presence of group specific antigen and antibodies in specific pathogen-free (SPF) chickens. CD4(+) and CD8(+) cell activity in the spleen, total and differential leukocyte counts in blood, and viral RNA levels in spleen were measured. Significant growth suppression was observed in the two ALV-J-infected groups. A strong immune response by infected groups was present in spleen at 2-weeks-of-age, but after 4-weeks-of-age, the response decreased quickly. The thymus and bursa showed persistent immunosuppression until 4-weeks-of-age. Proliferation of fibroblasts and dendritic cells were observed in immune organs at 4- and 5-weeks-of-age. However, the granulocyte cell number was markedly lower in the infected groups than in the control group. In group 1 (day 1 infection) CD4(+) cells increased during the second week but significantly decreased during the fourth week, while group 2 (day 7 infection) showed the opposite effect. Viral RNA increased significantly by the fourth week. These data identify 3~4 weeks post-infection as the key time at which the ALV-J virus exerts its immunosuppressive effects on the host. PMID:21897096

  12. The critical time of avian leukosis virus subgroup J-mediated immunosuppression during early stage infection in specific pathogen-free chickens

    PubMed Central

    Wang, Feng; Wang, Xiaowei; Chen, Hongbo; Liu, Jianzhu

    2011-01-01

    The critical time of avian leukosis virus subgroup J (ALV-J)-mediated immunosuppression was determined by body weight, relative immune organ weight, histopathology, and presence of group specific antigen and antibodies in specific pathogen-free (SPF) chickens. CD4+ and CD8+ cell activity in the spleen, total and differential leukocyte counts in blood, and viral RNA levels in spleen were measured. Significant growth suppression was observed in the two ALV-J-infected groups. A strong immune response by infected groups was present in spleen at 2-weeks-of-age, but after 4-weeks-of-age, the response decreased quickly. The thymus and bursa showed persistent immunosuppression until 4-weeks-of-age. Proliferation of fibroblasts and dendritic cells were observed in immune organs at 4- and 5-weeks-of-age. However, the granulocyte cell number was markedly lower in the infected groups than in the control group. In group 1 (day 1 infection) CD4+ cells increased during the second week but significantly decreased during the fourth week, while group 2 (day 7 infection) showed the opposite effect. Viral RNA increased significantly by the fourth week. These data identify 3~4 weeks post-infection as the key time at which the ALV-J virus exerts its immunosuppressive effects on the host. PMID:21897096

  13. Neurotropism in blackcaps (Sylvia atricapilla) and red-billed queleas (Quelea quelea) after highly pathogenic avian influenza virus H5N1 infection.

    PubMed

    Breithaupt, A; Kalthoff, D; Dale, J; Bairlein, F; Beer, M; Teifke, J P

    2011-09-01

    The epidemiologic role of passerine birds in the spread of highly pathogenic avian influenza virus (HPAIV) remains controversial. However, confirmed natural infections with HPAIV in Passeriformes, their close contact to poultry and humans, and their role as a human food source indicate a need for increased research on passerines. To date, there are only a few studies on viral shedding and pathomorphologic changes in songbirds infected with HPAIV. To investigate susceptibility, clinical outcome, virus spread, and pathomorphology, the authors inoculated oculo-oronasally 22 red-billed queleas (Quelea quelea) and 11 blackcaps (Sylvia atricapilla) with A/Cygnus cygnus/Germany/R65/2006 (H5N1) using 2 different doses of either 10(4) EID50 (50% egg infective dose) or 10(6) EID50 per animal. They monitored all birds for clinical signs and oropharyngeal and cloacal virus shedding. They also performed immunohistochemistry and obtained molecular virologic data by real-time reverse transcription polymerase chain reaction in tissue samples. In contrast to blackcaps, where 100% of the infected individuals died, queleas were much less susceptible, with a mortality of 82% and 18%, depending on the doses applied. In both species, the virus was shed within 3 to 6 days postinfection, mainly via the respiratory tract. Viral antigen was detected in 100% of the succumbed birds, particularly in the central nervous system. In blackcaps, the heart, lungs, and pancreas were mainly infected. In contrast, the pancreas was predominantly affected in queleas, whereas the heart and the lower respiratory tract were of minor relevance. The authors hypothesize that neurotropism should be considered a main factor for the fatal course of disease in Passeriformes after infection with HPAIV. PMID:20974871

  14. Clinical Characteristics of 26 Human Cases of Highly Pathogenic Avian Influenza A (H5N1) Virus Infection in China

    PubMed Central

    Xiang, Nijuan; Zhou, Lei; Huai, Yang; Feng, Luzhao; Peng, Zhibin; Li, Zhongjie; Xu, Cuiling; Li, Junhua; Hu, Chengping; Li, Qun; Xu, Xiaoling; Liu, Xuecheng; Liu, Zigui; Xu, Longshan; Chen, Yusheng; Luo, Huiming; Wei, Liping; Zhang, Xianfeng; Xin, Jianbao; Guo, Junqiao; Wang, Qiuyue; Yuan, Zhengan; Zhou, Longnv; Zhang, Kunzhao; Zhang, Wei; Yang, Jinye; Zhong, Xiaoning; Xia, Shichang; Li, Lanjuan; Cheng, Jinquan; Ma, Erdang; He, Pingping; Lee, Shui Shan; Wang, Yu; Uyeki, Timothy M.; Yang, Weizhong

    2008-01-01

    Background While human cases of highly pathogenic avian influenza A (H5N1) virus infection continue to increase globally, available clinical data on H5N1 cases are limited. We conducted a retrospective study of 26 confirmed human H5N1 cases identified through surveillance in China from October 2005 through April 2008. Methodology/Principal Findings Data were collected from hospital medical records of H5N1 cases and analyzed. The median age was 29 years (range 6–62) and 58% were female. Many H5N1 cases reported fever (92%) and cough (58%) at illness onset, and had lower respiratory findings of tachypnea and dyspnea at admission. All cases progressed rapidly to bilateral pneumonia. Clinical complications included acute respiratory distress syndrome (ARDS, 81%), cardiac failure (50%), elevated aminotransaminases (43%), and renal dysfunction (17%). Fatal cases had a lower median nadir platelet count (64.5×109 cells/L vs 93.0×109 cells/L, p = 0.02), higher median peak lactic dehydrogenase (LDH) level (1982.5 U/L vs 1230.0 U/L, p = 0.001), higher percentage of ARDS (94% [n = 16] vs 56% [n = 5], p = 0.034) and more frequent cardiac failure (71% [n = 12] vs 11% [n = 1], p = 0.011) than nonfatal cases. A higher proportion of patients who received antiviral drugs survived compared to untreated (67% [8/12] vs 7% [1/14], p = 0.003). Conclusions/Significance The clinical course of Chinese H5N1 cases is characterized by fever and cough initially, with rapid progression to lower respiratory disease. Decreased platelet count, elevated LDH level, ARDS and cardiac failure were associated with fatal outcomes. Clinical management of H5N1 cases should be standardized in China to include early antiviral treatment for suspected H5N1 cases. PMID:18716658

  15. Reduced experimental infectivity and transmissibility of intercontinental H5 (H5N8 and H5N2) compared to Eurasian H5N1 highly pathogenic avian influenza viruses for chickens, turkeys, and Japanese quail

    Technology Transfer Automated Retrieval System (TEKTRAN)

    H5N1 high pathogenicity avian influenza (HPAI) virus (HPAIV) emerged in 1996 in Guangdong China and has since spread to infect and cause deaths in wild birds, poultry and humans in over 63 countries in Asia, Europe and Africa; and more recently a reassortant H5N8 clade 2.3.4.4 HPAI virus has spread ...

  16. Pathogenic human viruses in coastal waters

    USGS Publications Warehouse

    Griffin, Dale W.; Donaldson, Kim A.; Paul, J.H.; Rose, Joan B.

    2003-01-01

    This review addresses both historical and recent investigations into viral contamination of marine waters. With the relatively recent emergence of molecular biology-based assays, a number of investigations have shown that pathogenic viruses are prevalent in marine waters being impacted by sewage. Research has shown that this group of fecal-oral viral pathogens (enteroviruses, hepatitis A viruses, Norwalk viruses, reoviruses, adenoviruses, rotaviruses, etc.) can cause a broad range of asymptomatic to severe gastrointestinal, respiratory, and eye, nose, ear, and skin infections in people exposed through recreational use of the water. The viruses and the nucleic acid signature survive for an extended period in the marine environment. One of the primary concerns of public health officials is the relationship between the presence of pathogens and the recreational risk to human health in polluted marine environments. While a number of studies have attempted to address this issue, the relationship is still poorly understood. A contributing factor to our lack of progress in the field has been the lack of sensitive methods to detect the broad range of both bacterial and viral pathogens. The application of new and advanced molecular methods will continue to contribute to our current state of knowledge in this emerging and

  17. Pathogenic Human Viruses in Coastal Waters

    PubMed Central

    Griffin, Dale W.; Donaldson, Kim A.; Paul, John H.; Rose, Joan B.

    2003-01-01

    This review addresses both historical and recent investigations into viral contamination of marine waters. With the relatively recent emergence of molecular biology-based assays, a number of investigations have shown that pathogenic viruses are prevalent in marine waters being impacted by sewage. Research has shown that this group of fecal-oral viral pathogens (enteroviruses, hepatitis A viruses, Norwalk viruses, reoviruses, adenoviruses, rotaviruses, etc.) can cause a broad range of asymptomatic to severe gastrointestinal, respiratory, and eye, nose, ear, and skin infections in people exposed through recreational use of the water. The viruses and the nucleic acid signature survive for an extended period in the marine environment. One of the primary concerns of public health officials is the relationship between the presence of pathogens and the recreational risk to human health in polluted marine environments. While a number of studies have attempted to address this issue, the relationship is still poorly understood. A contributing factor to our lack of progress in the field has been the lack of sensitive methods to detect the broad range of both bacterial and viral pathogens. The application of new and advanced molecular methods will continue to contribute to our current state of knowledge in this emerging and important field. PMID:12525429

  18. Bagaza virus is pathogenic and transmitted by direct contact in experimentally infected partridges, but is not infectious in house sparrows and adult mice.

    PubMed

    Llorente, Francisco; Pérez-Ramírez, Elisa; Fernández-Pinero, Jovita; Elizalde, Maia; Figuerola, Jordi; Soriguer, Ramón C; Jiménez-Clavero, Miguel Ángel

    2015-01-01

    Bagaza virus (BAGV) is a mosquito-borne flavivirus belonging to the Ntaya serocomplex. In 2010, a disease outbreak was reported in Cádiz (Southern Spain) affecting game birds (red-legged partridges and common pheasants). In this work, red-legged partridges were inoculated experimentally with infectious BAGV isolated from this outbreak in order to make a complete clinical and analytical assessment of the disease caused by the pathogen in this species. Viral load (by real-time RT-PCR) in blood, oral and cloacal swabs, and feathers, and neutralizing antibody titres (by VNT) were measured. In order to determine direct contact transmission, non-inoculated partridges were caged together with the inoculated ones. To assess infectiousness in other species, house sparrows and mice were also inoculated with the virus. All the inoculated partridges were clinically affected, and 30% of them died. All the infected individuals lost weight, with larger losses being recorded in females. Conversely, no mortality or disease symptoms were observed in the sparrows or mice. Remarkably, all the contact partridges acquired the infection by direct (non-vectored) transmission. This study confirms that the red-legged partridge is a susceptible host for BAGV infection, and that this pathogen is transmitted by direct contact. Long-lasting viral loads detected in calami of immature feathers demonstrate that feather sampling could be a useful strategy in active surveillance programs for early detection of BAGV. PMID:26338714

  19. Loss of IL-17-producing CD8 T cells during late chronic stage of pathogenic simian immunodeficiency virus infection.

    PubMed

    Nigam, Pragati; Kwa, Suefen; Velu, Vijayakumar; Amara, Rama Rao

    2011-01-15

    Progressive disease caused by pathogenic SIV/HIV infections is marked by systemic hyperimmune activation, immune dysregulation, and profound depletion of CD4(+) T cells in lymphoid and gastrointestinal mucosal tissues. IL-17 is important for protective immunity against extracellular bacterial infections at mucosa and for maintenance of mucosal barrier. Although IL-17-secreting CD4 (Th17) and CD8 (Tc17) T cells have been reported, very little is known about the latter subset for any infectious disease. In this study, we characterized the anatomical distribution, phenotype, and functional quality of Tc17 and Th17 cells in healthy (SIV-) and SIV+ rhesus macaques. In healthy macaques, Tc17 and Th17 cells were present in all lymphoid and gastrointestinal tissues studied with predominance in small intestine. About 50% of these cells coexpressed TNF-α and IL-2. Notably, ∼50% of Tc17 cells also expressed the co-inhibitory molecule CTLA-4, and only a minority (<20%) expressed granzyme B suggesting that these cells possess more of a regulatory than cytotoxic phenotype. After SIV infection, unlike Th17 cells, Tc17 cells were not depleted during the acute phase of infection. However, the frequency of Tc17 cells in SIV-infected macaques with AIDS was lower compared with that in healthy macaques demonstrating the loss of these cells during end-stage disease. Antiretroviral therapy partially restored the frequency of Tc17 and Th17 cells in the colorectal mucosa. Depletion of Tc17 cells was not observed in colorectal mucosa of chronically infected SIV+ sooty mangabeys. In conclusion, our results suggest a role for Tc17 cells in regulating disease progression during pathogenic SIV infection. PMID:21148794

  20. Effect of porcine circovirus type 2a or 2b on infection kinetics and pathogenicity of two genetically divergent strains of porcine reproductive and respiratory syndrome virus in the conventional pig model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to characterize the infection dynamics and pathogenicity of two heterologous type 2 porcine reproductive and respiratory syndrome virus (PRRSV) isolates in a conventional pig model under the influence of concurrent porcine circovirus (PCV) subtype 2a or 2b infection. ...

  1. 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

  2. Experimental infection of a North American raptor, American kestrel (Falco sparverius), with highly pathogenic avian influenza virus (H5N1)

    USGS Publications Warehouse

    Hall, J.S.; Ip, H.S.; Franson, J.C.; Meteyer, C.; Nashold, S.; Teslaa, J.L.; French, J.; Redig, P.; Brand, C.

    2009-01-01

    Several species of wild raptors have been found in Eurasia infected with highly pathogenic avian influenza virus (HPAIV) subtype H5N1. Should HPAIV (H5N1) reach North America in migratory birds, species of raptors are at risk not only from environmental exposure, but also from consuming infected birds and carcasses. In this study we used American kestrels as a representative species of a North American raptor to examine the effects of HPAIV (H5N1) infection in terms of dose response, viral shedding, pathology, and survival. Our data showed that kestrels are highly susceptible to HPAIV (H5N1). All birds typically died or were euthanized due to severe neurologic disease within 4-5 days of inoculation and shed significant amounts of virus both orally and cloacally, regardless of dose administered. The most consistent microscopic lesions were necrosis in the brain and pancreas. This is the first experimental study of HPAIV infection in a North American raptor and highlights the potential risks to birds of prey if HPAIV (H5N1) is introduced into North America.

  3. Differences of immune responses between Tongcheng (Chinese local breed) and Large White pigs after artificial infection with highly pathogenic porcine reproductive and respiratory syndrome virus.

    PubMed

    Liang, Wan; Li, Zhenhong; Wang, Peng; Fan, Pengcheng; Zhang, Yu; Zhang, Qingde; Wang, Yan; Xu, Xuewen; Liu, Bang

    2016-04-01

    Porcine reproductive and respiratory syndrome (PRRS) is one of the severest infectious diseases of pigs throughout the world. Pigs of different breeds infected with PRRS virus (PRRSV) have been reported to vary in their immune responses. Here, the differences of immune responses to highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) were investigated by artificially infecting Tongcheng (TC) pigs (a Chinese indigenous breed) and Large White (LW) pigs with PRRSV WUH3. Compared to LW pigs, TC pigs showed less severe symptoms and lower level of viral load. The routine blood test results indicated that TC pigs were relatively steady in terms of erythrocyte, leukocyte and platelet. Additionally, PRRSV infection induced higher IFN-γ activity in TC pigs, but stimulated an excessive level of IL-10 and IL-12p40 in LW pigs. Our study provides direct evidence that TC pigs have stronger resistance to early PRRSV infection than LW pigs, suggesting that the resistance of pigs to PRRSV is likely associated with breed differences. PMID:26878768

  4. Risk Reduction Modeling of High Pathogenicity Avian Influenza Virus Titers in Nonpasteurized Liquid Egg Obtained from Infected but Undetected Chicken Flocks.

    PubMed

    Weaver, J Todd; Malladi, Sasidhar; Spackman, Erica; Swayne, David E

    2015-11-01

    Control of highly pathogenic avian influenza (HPAI) outbreaks in poultry has traditionally involved the establishment of disease containment zones, where poultry products are only permitted to move from within a zone under permit. Nonpasteurized liquid egg (NPLE) is one such commodity for which movements may be permitted, considering inactivation of HPAI virus via pasteurization. Active surveillance testing at the flock level, using targeted matrix gene real-time reversed transcriptase-polymerase chain reaction testing (RRT-PCR) has been incorporated into HPAI emergency response plans as the primary on-farm diagnostic test procedure to detect HPAI in poultry and is considered to be a key risk mitigation measure. To inform decisions regarding the potential movement of NPLE to a pasteurization facility, average HPAI virus concentrations in NPLE produced from a HPAI virus infected, but undetected, commercial table-egg-layer flock were estimated for three HPAI virus strains using quantitative simulation models. Pasteurization under newly proposed international design standards (5 log10 reduction) is predicted to inactivate HPAI virus in NPLE to a very low concentration of less than 1 embryo infectious dose (EID)50 /mL, considering the predicted virus titers in NPLE from a table-egg flock under active surveillance. Dilution of HPAI virus from contaminated eggs in eggs from the same flock, and in a 40,000 lb tanker-truck load of NPLE containing eggs from disease-free flocks was also considered. Risk assessment can be useful in the evaluation of commodity-specific risk mitigation measures to facilitate safe trade in animal products from countries experiencing outbreaks of highly transmissible animal diseases. PMID:25867713

  5. Investigation of tick-borne viruses as pathogens of humans in South Africa and evidence of Dugbe virus infection in a patient with prolonged thrombocytopenia.

    PubMed Central

    Burt, F. J.; Spencer, D. C.; Leman, P. A.; Patterson, B.; Swanepoel, R.

    1996-01-01

    In the course of investigating suspected cases of viral haemorrhagic fever in South Africa patients were encountered who had been bitten by ticks, but who lacked evidence of infection with Crimean-Congo haemorrhagic fever (CCHF) virus or non-viral tick-borne agents. Cattle sera were tested by enzyme-linked immunoassay to determine whether tick-borne viruses other than CCHF occur in the country. The prevalence of antibody in cattle sera was 905/2116 (42.8%) for CCHF virus, 70/1358 (5.2%) for Dugbe, 21/1358 (1.5%) for louping ill, 6/450 (1.3%) for West Nile, 7/1358 (0.5%) for Nairobi sheep disease, 3/625 (0.5%) for Kadam and 2/450 (0.4%) for Chenuda. No reactions were recorded with Hazara, Bahig, Bhanja, Thogoto and Dhori viruses. The CCHF findings confirmed previous observations that the virus is widely prevalent within the distribution range of ticks of the genus Hyalomma, while antibody activity to Dugbe antigen was detected only within the distribution range of the tick Amblyomma hebraeum. Cross-reactivity for the nairoviruses, Hazara, Nairobi sheep disease and Dugbe, was detected in serum samples from 3/72 human patients with confirmed CCHF infection, and serum from 1/162 other patients reacted monospecifically with Dugbe antigen. The latter patient suffered from febrile illness with prolonged thrombocytopenia. PMID:8666081

  6. Transcription analysis on response of porcine alveolar macrophages to co-infection of the highly pathogenic porcine reproductive and respiratory syndrome virus and Mycoplasma hyopneumoniae.

    PubMed

    Li, Bin; Du, Luping; Xu, Xiangwei; Sun, Bing; Yu, Zhengyu; Feng, Zhixin; Liu, Maojun; Wei, Yanna; Wang, Haiyan; Shao, Guoqing; He, Kongwang

    2015-01-22

    Porcine respiratory disease complex (PRDC) is of great concern economically, for swine producers worldwide. Co-infections with porcine reproductive and respiratory syndrome virus (PRRSV) and Mycoplasma hyopneumoniae (Mhp) are considered the major causative agents of PRDC, and responsible for mass mortality in pigs. Nevertheless, the molecular mechanisms underlying the host factors involved in pathogenesis and persistent infection have not been clearly established because of a lack of information regarding host responses following co-infection. In the current study, high throughput cDNA microarray assays were employed to evaluate host responses of porcine alveolar macrophages (PAM) to co-infection with highly pathogenic PRRSV (HP-PRRSV) and Mhp. A total of 2152 and 1760 genes were identified as being differentially expressed between the control group and PRRSV+Mhp co-infected group at 6 and 15 h post infection, respectively. The DE genes were involved in many vital functional classes, including inflammatory response, immune response, apoptosis, defense response, signal transduction. The pathway analysis demonstrated that the most significant pathways were associated with chemokine signaling pathway, cytokine, TLR, RLR and NLR signaling pathways and Jak-STAT signaling pathway. STRING analysis demonstrated that IL-1β is an integral gene in co-infections with PRRSV and Mhp. The present study is the first to document the response of PAMs to co-infection with HP-PRRSV and Mhp. The observed gene expression profile could help with the screening of potential host agents for reducing the prevalence of co-infections, and to further develop our understanding of the molecular pathogenesis associated with PRRSV and Mhp co-infection in pigs. PMID:25445346

  7. Effect of age on pathogenesis and innate immune responses in Pekin ducks infected with different H5N1 highly pathogenic avian influenza viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The pathogenicity of H5N1 highly pathogenic avian influenza (HPAI) viruses in domestic ducks varies between different viruses and is affected by the age of the ducks, with younger ducks presenting more severe disease. In order to better understand the pathobiology of H5N1 HPAI in ducks, including t...

  8. Systems Analysis of Immune Responses in Marek's Disease Virus-Infected Chickens Identifies a Gene Involved in Susceptibility and Highlights a Possible Novel Pathogenicity Mechanism▿†

    PubMed Central

    Smith, Jacqueline; Sadeyen, Jean-Remy; Paton, Ian R.; Hocking, Paul M.; Salmon, Nigel; Fife, Mark; Nair, Venugopal; Burt, David W.; Kaiser, Pete

    2011-01-01

    Marek's disease virus (MDV) is a highly contagious oncogenic alphaherpesvirus that causes disease that is both a cancer model and a continuing threat to the world's poultry industry. This comprehensive gene expression study analyzes the host response to infection in both resistant and susceptible lines of chickens and inherent expression differences between the two lines following the infection of the host. A novel pathogenicity mechanism, involving the downregulation of genes containing HIC1 transcription factor binding sites as early as 4 days postinfection, was suggested from this analysis. HIC1 drives antitumor mechanisms, suggesting that MDV infection switches off genes involved in antitumor regulation several days before the expression of the MDV oncogene meq. The comparison of the gene expression data to previous QTL data identified several genes as candidates for involvement in resistance to MD. One of these genes, IRG1, was confirmed by single nucleotide polymorphism analysis to be involved in susceptibility. Its precise mechanism remains to be elucidated, although the analysis of gene expression data suggests it has a role in apoptosis. Understanding which genes are involved in susceptibility/resistance to MD and defining the pathological mechanisms of the disease gives us a much greater ability to try to reduce the incidence of this virus, which is costly to the poultry industry in terms of both animal welfare and economics. PMID:21865384

  9. Combinations of Oseltamivir and T-705 Extend the Treatment Window for Highly Pathogenic Influenza A(H5N1) Virus Infection in Mice

    PubMed Central

    Marathe, Bindumadhav M.; Wong, Sook-San; Vogel, Peter; Garcia-Alcalde, Fernando; Webster, Robert G.; Webby, Richard J.; Najera, Isabel; Govorkova, Elena A.

    2016-01-01

    Current anti-influenza therapy depends on administering drugs soon after infection, which is often impractical. We assessed whether combinations of oseltamivir (a neuraminidase inhibitor) and T-705 (a nonspecific inhibitor of viral polymerases) could extend the window for treating lethal infection with highly pathogenic A(H5N1) influenza virus in mice. Combination therapy protected 100% of mice, even when delayed until 96 h postinoculation. Compared to animals receiving monotherapy, mice receiving combination therapy had reduced viral loads and restricted viral spread in lung tissues, limited lung damage, and decreased inflammatory cytokine production. Next-generation sequencing showed that virus populations in T-705–treated mice had greater genetic variability, with more frequent transversion events, than did populations in control and oseltamivir-treated mice, but no substitutions associated with resistance to oseltamivir or T-705 were detected. Thus, combination therapy extended the treatment window for A(H5N1) influenza infection in mice and should be considered for evaluation in a clinical setting. PMID:27221530

  10. Combinations of Oseltamivir and T-705 Extend the Treatment Window for Highly Pathogenic Influenza A(H5N1) Virus Infection in Mice.

    PubMed

    Marathe, Bindumadhav M; Wong, Sook-San; Vogel, Peter; Garcia-Alcalde, Fernando; Webster, Robert G; Webby, Richard J; Najera, Isabel; Govorkova, Elena A

    2016-01-01

    Current anti-influenza therapy depends on administering drugs soon after infection, which is often impractical. We assessed whether combinations of oseltamivir (a neuraminidase inhibitor) and T-705 (a nonspecific inhibitor of viral polymerases) could extend the window for treating lethal infection with highly pathogenic A(H5N1) influenza virus in mice. Combination therapy protected 100% of mice, even when delayed until 96 h postinoculation. Compared to animals receiving monotherapy, mice receiving combination therapy had reduced viral loads and restricted viral spread in lung tissues, limited lung damage, and decreased inflammatory cytokine production. Next-generation sequencing showed that virus populations in T-705-treated mice had greater genetic variability, with more frequent transversion events, than did populations in control and oseltamivir-treated mice, but no substitutions associated with resistance to oseltamivir or T-705 were detected. Thus, combination therapy extended the treatment window for A(H5N1) influenza infection in mice and should be considered for evaluation in a clinical setting. PMID:27221530

  11. Differences in innate immune responses to H5N1 highly pathogenic avian influenza virus infection between Pekin, Muscovy and Mallard ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ducks have been implicated in the dissemination and evolution of H5N1 highly pathogenic avian influenza (HPAI) viruses. However, differences in pathogenicity and response to vaccination have been observed between different duck species. In this study we examined the pathogenicity of H5N1 HPAI viru...

  12. [ZIKA--VIRUS INFECTION].

    PubMed

    Velev, V

    2016-01-01

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

  13. Highly pathogenic avian influenza virus H5N1 infection in a long-distance migrant shorebird under migratory and non-migratory states.

    PubMed

    Reperant, Leslie A; van de Bildt, Marco W G; van Amerongen, Geert; Buehler, Debbie M; Osterhaus, Albert D M E; Jenni-Eiermann, Susi; Piersma, Theunis; Kuiken, Thijs

    2011-01-01

    Corticosterone regulates physiological changes preparing wild birds for migration. It also modulates the immune system and may lead to increased susceptibility to infection, with implications for the spread of pathogens, including highly pathogenic avian influenza virus (HPAIV) H5N1. The red knot (Calidris canutus islandica) displays migratory changes in captivity and was used as a model to assess the effect of high plasma concentration of corticosterone on HPAIV H5N1 infection. We inoculated knots during pre-migration (N = 6), fueling (N = 5), migration (N = 9) and post-migration periods (N = 6). Knots from all groups shed similar viral titers for up to 5 days post-inoculation (dpi), peaking at 1 to 3 dpi. Lesions of acute encephalitis, associated with virus replication in neurons, were seen in 1 to 2 knots per group, leading to neurological disease and death at 5 to 11 dpi. Therefore, the risk of HPAIV H5N1 infection in wild birds and of potential transmission between wild birds and poultry may be similar at different times of the year, irrespective of wild birds' migratory status. However, in knots inoculated during the migration period, viral shedding levels positively correlated with pre-inoculation plasma concentration of corticosterone. Of these, knots that did not become productively infected had lower plasma concentration of corticosterone. Conversely, elevated plasma concentration of corticosterone did not result in an increased probability to develop clinical disease. These results suggest that birds with elevated plasma concentration of corticosterone at the time of migration (ready to migrate) may be more susceptible to acquisition of infection and shed higher viral titers--before the onset of clinical disease--than birds with low concentration of corticosterone (not ready for take-off). Yet, they may not be more prone to the development of clinical disease. Therefore, assuming no effect of sub-clinical infection on the likelihood of

  14. Molecular characterization of porcine SARM1 and its role in regulating TLRs signaling during highly pathogenic porcine reproductive and respiratory syndrome virus infection in vivo.

    PubMed

    Zhou, Xiang; Jiang, Tengfei; Du, Xiaochuan; Zhou, Ping; Jiang, Zhihua; Michal, Jennifer J; Liu, Bang

    2013-01-01

    Toll-like receptors (TLRs) are important pattern-recognition receptors (PRRs) that trigger innate immune response and mediate acquired immunity. Evidence has shown that SARM1 (sterile-α and TIR motif containing protein 1) is one of five TIR domain-containing adaptor proteins involved in TLRs signaling transduction. In the present study, a full-length cDNA sequence was cloned for the porcine SARM1 gene, which contains nine exons. Using the radiation hybrid mapping approach, we assigned the porcine gene to SSC12 q13. Under the normal condition, porcine SARM1 was highly expressed in brain and spleen. Polyinosinic-polycytidylic acid (poly (I:C)) weakly induced the porcine SARM1 expression in the early stimulation. We found that porcine SARM1 protein is localized in mitochondria and attenuates NF-κB activation induced by stimulation and infection. The quantitative real-time PCR (Q-PCR) analysis showed that the expression of porcine SARM1 significantly decreased in several tissues of Tongcheng pigs infected with highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV). Gene-interaction network analysis for porcine SARM1 in porcine alveolar macrophages (PAMs) showed that down-regulation of SARM1 gene in infected Tongcheng pig may modulate TRIF-depend TLRs signaling and regulate the expression of disease-resistant genes and inflammatory genes. Our findings provide evidence that porcine SARM1 may play an important role in immune regulation with PRRSV infection. PMID:22366489

  15. Outbreak of H5N2 highly pathogenic avian Influenza A virus infection in two commercial layer facilities: lesions and viral antigen distribution.

    PubMed

    Arruda, Paulo H E; Stevenson, Gregory W; Killian, Mary L; Burrough, Eric R; Gauger, Phillip C; Harmon, Karen M; Magstadt, Drew R; Yoon, Kyoung-Jin; Zhang, Jianqiang; Madson, Darin M; Piñeyro, Pablo; Derscheid, Rachel J; Schwartz, Kent J; Cooper, Vickie L; Halbur, Patrick G; Main, Rodger G; Sato, Yuko; Arruda, Bailey L

    2016-09-01

    The largest outbreak of highly pathogenic avian Influenza A virus (HPAIV) infection in U.S. history began in December 2014 resulting in the euthanasia of millions of birds and collateral economic consequences to the U.S. poultry industry. We describe 2 cases of H5N2 HPAIV infection in laying hens in Iowa. Following a sharp increase in mortality with minimal clinical signs, 15 dead birds, from 2 unrelated farms, were submitted to the Iowa State University Veterinary Diagnostic Laboratory. Common lesions included diffuse edema and multifocal hemorrhage of the comb, catarrhal exudate in the oropharynx, and multifocal tracheal hemorrhage. Less common lesions included epicardial petechiae, splenic hemorrhage, and pancreatic necrosis. Influenza A virus nucleoprotein was detected by immunohistochemistry in multiple cell types including ependymal cells, the choroid plexus, neurons, respiratory epithelium and macrophages in the lung, cardiac myocytes, endothelial cells, necrotic foci in the spleen, Kupffer cells in the liver, and necrotic acinar cells in the pancreas. Real-time polymerase chain reaction and sequencing confirmed H5N2 HPAIV with molecular characteristics similar to other contemporary U.S. H5N2 HPAIVs in both cases. PMID:27423731

  16. Immune-related gene expression in response to H11N9 low pathogenic avian influenza virus infection in chicken and Pekin duck peripheral blood mononuclear cells.

    PubMed

    Adams, Sean C; Xing, Zheng; Li, Jinling; Cardona, Carol J

    2009-05-01

    The duck and chicken are important hosts of avian influenza virus (AIV) with distinctive responses to infection. Frequently, AIV infections in ducks are asymptomatic and long-lasting in contrast to the clinically apparent and transient infections observed in chickens. These differences may be due in part to the host response to AIV infection. Using real-time quantitative PCR, we examined the expression of immune-related genes in response to low pathogenic AIV H11N9 infection in peripheral blood mononuclear cells (PBMC) isolated from the blood of chickens and Pekin ducks. While chicken PBMC expressed IL-1beta and IL-6 at high levels similar to mammalian species, duck PBMC expression levels were minimal or unchanged. Similarly, duck IFN-beta expression was nearly unaffected, whereas chicken expression was highly upregulated. Chicken IFN-gamma was expressed to higher levels than duck IFN-gamma, while IFN-alpha was expressed similarly by both species. IL-2 was elevated early in infection in duck PBMC, but returned to baseline levels by the end of the experiment; in contrast, IL-2 was weakly induced in chicken PBMC at late time points. TLR-7 and MHC class I molecule expressions were conserved between species, whereas duck MHC class II expression was downregulated and chicken expression was unchanged. These results show distinct PBMC expression patterns of pro-inflammatory cytokines and IFNs between species. The differences in pro-inflammatory cytokine and IFN expression reflect the asymptomatic and lasting infection observed in ducks and the tendency towards clinical signs and rapid clearance seen in chickens. These results highlight important differences in the host response to AIV of two species thought to be critical in the genesis and maintenance of epidemic strains of AIV. PMID:19250679

  17. A soluble envelope protein of endogenous retrovirus (FeLIX) present in serum of domestic cats mediates infection of a pathogenic variant of feline leukemia virus.

    PubMed

    Sakaguchi, Shoichi; Shojima, Takayuki; Fukui, Daisuke; Miyazawa, Takayuki

    2015-03-01

    T-lymphotropic feline leukemia virus (FeLV-T), a highly pathogenic variant of FeLV, induces severe immunosuppression in cats. FeLV-T is fusion defective because in its PHQ motif, a gammaretroviral consensus motif in the N terminus of an envelope protein, histidine is replaced with aspartate. Infection by FeLV-T requires FeLIX, a truncated envelope protein encoded by an endogenous FeLV, for transactivation of infectivity and Pit1 for binding FeLIX. Although Pit1 is present in most tissues in cats, the expression of FeLIX is limited to certain cells in lymphoid organs. Therefore, the host cell range of FeLV-T was thought to be restricted to cells expressing FeLIX. However, because FeLIX is a soluble factor and is expressed constitutively in lymphoid organs, we presumed it to be present in blood and evaluated its activities in sera of various mammalian species using a pseudotype assay. We demonstrated that cat serum has FeLIX activity at a functional level, suggesting that FeLIX is present in the blood and that FeLV-T may be able to infect cells expressing Pit1 regardless of the expression of FeLIX in vivo. In addition, FeLIX activities in sera were detected only in domestic cats and not in other feline species tested. To our knowledge, this is the first report to prove that a large amount of truncated envelope protein of endogenous retrovirus is circulating in the blood to facilitate the infection of a pathogenic exogenous retrovirus. PMID:25395593

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  19. Pathobiology of avian influenza virus infections in wild birds

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  20. Human pathogenic hantaviruses and prevention of infection

    PubMed Central

    Schönrich, Günther; Klempa, Boris

    2011-01-01

    Hantaviruses are emerging viruses which are hosted by small mammals. When transmitted to humans, they can cause two clinical syndromes, hemorrhagic fever with renal syndrome or hantavirus cardiopulmonary syndrome. The review compiles the current list of hantaviruses which are thought to be pathogenic in humans on the basis of molecular or at least serological evidence. Whereas induction of a neutralizing humoral immune response is considered to be protective against infection, the dual role of cellular immunity (protection versus immunopathogenicity) is discussed. For immunization, inactivated virus vaccines are licensed in certain Asian countries. Moreover, several classical and molecular vaccine approaches are in pre-clinical stages of development. The development of hantavirus vaccines is hampered by the lack of adequate animal models of hantavirus-associated disease. In addition to active immunization strategies, the review summarizes other ways of infection prevention, as passive immunization, chemoprophylaxis and exposition prophylaxis. PMID:21508676

  1. Sequential Activation of Two Pathogen-Sensing Pathways Required for Type I Interferon Expression and Resistance to an Acute DNA Virus Infection.

    PubMed

    Xu, Ren-Huan; Wong, Eric B; Rubio, Daniel; Roscoe, Felicia; Ma, Xueying; Nair, Savita; Remakus, Sanda; Schwendener, Reto; John, Shinu; Shlomchik, Mark; Sigal, Luis J

    2015-12-15

    Toll-like receptor 9 (TLR9), its adaptor MyD88, the downstream transcription factor interferon regulatory factor 7 (IRF7), and type I interferons (IFN-I) are all required for resistance to infection with ectromelia virus (ECTV). However, it is not known how or in which cells these effectors function to promote survival. Here, we showed that after infection with ECTV, the TLR9-MyD88-IRF7 pathway was necessary in CD11c(+) cells for the expression of proinflammatory cytokines and the recruitment of inflammatory monocytes (iMos) to the draining lymph node (dLN). In the dLN, the major producers of IFN-I were infected iMos, which used the DNA sensor-adaptor STING to activate IRF7 and nuclear factor κB (NF-κB) signaling to induce the expression of IFN-α and IFN-β, respectively. Thus, in vivo, two pathways of DNA pathogen sensing act sequentially in two distinct cell types to orchestrate resistance to a viral disease. PMID:26682986

  2. Using mean infectious dose of wild duck-and poultry-origin high and low pathogenicity avian influenza viruses as one measure of infectivity and adaptation to poultry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mean infectious doses of selected avian influenza virus (AIV) isolates, determined in domestic poultry under experimental conditions, were shown to be both host and virus dependent and could be considered one measure of the infectivity and adaptation to a specific host. As such, the mean infect...

  3. Persistence of Highly Pathogenic Avian Influenza Viruses in Natural Ecosystems

    PubMed Central

    Feare, Chris J.; Renaud, François; Thomas, Frédéric; Gauthier-Clerc, Michel

    2010-01-01

    Understanding of ecologic factors favoring emergence and maintenance of highly pathogenic avian influenza (HPAI) viruses is limited. Although low pathogenic avian influenza viruses persist and evolve in wild populations, HPAI viruses evolve in domestic birds and cause economically serious epizootics that only occasionally infect wild populations. We propose that evolutionary ecology considerations can explain this apparent paradox. Host structure and transmission possibilities differ considerably between wild and domestic birds and are likely to be major determinants of virulence. Because viral fitness is highly dependent on host survival and dispersal in nature, virulent forms are unlikely to persist in wild populations if they kill hosts quickly or affect predation risk or migratory performance. Interhost transmission in water has evolved in low pathogenic influenza viruses in wild waterfowl populations. However, oropharyngeal shedding and transmission by aerosols appear more efficient for HPAI viruses among domestic birds. PMID:20587174

  4. Analysis of the swine tracheobronchial lymphnode transcriptomic response to infection with a Chinese highly pathogenic strain of porcine reproductive and respiratory syndrome virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Porcine reproductive and respiratory syndrome virus (PRRSV) is a major pathogen of swine worldwide. Emergence in 2006 of a novel highly pathogenic PRRSV (HP-PRRSV) isolate in China necessitated a comparative investigation into the host transcriptome response in tracheobronchial lymph nod...

  5. Analysis of the swine tracheobronchial lymphnode transcriptomic response to infection with a Chinese highly pathogenic strain of porcine reproductive and respiratory syndrome virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Porcine reproductive and respiratory syndrome virus (PRRSV) is a major pathogen of swine worldwide. Emergence in 2006 of a novel highly pathogenic PRRSV (HP-PRRSV) isolate in China necessitated a comparative investigation into the host transcriptome response in tracheobronchial lymph nodes (TBLN) 14...

  6. Swine tracheobronchial lymph node mRNA responses in swine infected with a highly pathogenic strain of porcine reproductive and respiratory syndrome virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Porcine reproductive and respiratory syndrome virus (PRRSV) is a major pathogen of swine worldwide. Emergence in 2006 of a novel highly pathogenic PRRSV (HP-PRRSV) isolate in China necessitated a comparative investigation into the host transcriptome response in tracheobronchial lymph nodes (TBLN) 14...

  7. Highly Pathogenic Avian Influenza H5N8 Clade 2.3.4.4 Virus: Equivocal Pathogenicity and Implications for Surveillance Following Natural Infection in Breeder Ducks in the United Kingdom.

    PubMed

    Núñez, A; Brookes, S M; Reid, S M; Garcia-Rueda, C; Hicks, D J; Seekings, J M; Spencer, Y I; Brown, I H

    2016-02-01

    Since early 2014, several outbreaks involving novel reassortant highly pathogenic avian influenza (HPAI) A(H5N8) viruses have been detected in poultry and wild bird species in Asia, Europe and North America. These viruses have been detected in apparently healthy and dead wild migratory birds, as well as in domestic chickens, turkeys, geese and ducks. In this study, we describe the pathology of an outbreak of H5N8 HPAIV in breeder ducks in the UK. A holding with approximately 6000 breeder ducks, aged approximately 60 weeks, showed a gradual reduction in egg production and increased mortality over a 7-day period. Post-mortem examination revealed frequent fibrinous peritonitis, with severely haemorrhagic ovarian follicles and occasional splenic and pancreatic necrosis and high incidence of mycotic granulomas in the air sacs and lung. Low-to-moderate levels of HPAI H5N8 virus were detected mainly in respiratory and digestive tract, with minor involvement of other organs. Although histopathological examination confirmed the gross pathology findings, intralesional viral antigen detection by immunohistochemistry was not observed. Immunolabelled cells were rarely only present in inflamed air sacs and serosa, usually superficial to granulomatous inflammation. Abundant bacterial microcolonies were observed in haemorrhagic ovaries and oviduct. The limited viral tissue distribution and presence of inter-current fungal and bacterial infections suggest a minor role for HPAIV H5N8 in clinical disease in layer ducks. PMID:26519234

  8. Detecting the emergence of novel, zoonotic viruses pathogenic to humans

    PubMed Central

    2015-01-01

    RNA viruses, with their high potential for mutation and epidemic spread, are the most common class of pathogens found as new causes of human illness. Despite great advances made in diagnostic technology since the 1950s, the annual rate at which novel virulent viruses have been found has remained at 2–3. Most emerging viruses are zoonoses; they have jumped from mammal or bird hosts to humans. An analysis of virus discovery indicates that the small number of novel viruses discovered annually is an artifact of inadequate surveillance in tropical and subtropical countries, where even established endemic pathogens are often misdiagnosed. Many of the emerging viruses of the future are already infecting humans but remain to be uncovered by a strategy of disease surveillance in selected populations. PMID:25416679

  9. Schmallenberg virus infection.

    PubMed

    Wernike, K; Elbers, A; Beer, M

    2015-08-01

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

  10. Yellow Fever Virus Infection

    PubMed Central

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

    1971-01-01

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

  11. Feline immunodeficiency virus infection.

    PubMed

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

    1989-05-01

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

  12. Integrated Omics Analysis of Pathogenic Host Responses during Pandemic H1N1 Influenza Virus Infection: The Crucial Role of Lipid Metabolism.

    PubMed

    Tisoncik-Go, Jennifer; Gasper, David J; Kyle, Jennifer E; Eisfeld, Amie J; Selinger, Christian; Hatta, Masato; Morrison, Juliet; Korth, Marcus J; Zink, Erika M; Kim, Young-Mo; Schepmoes, Athena A; Nicora, Carrie D; Purvine, Samuel O; Weitz, Karl K; Peng, Xinxia; Green, Richard R; Tilton, Susan C; Webb-Robertson, Bobbie-Jo; Waters, Katrina M; Metz, Thomas O; Smith, Richard D; Kawaoka, Yoshihiro; Suresh, M; Josset, Laurence; Katze, Michael G

    2016-02-10

    Pandemic influenza viruses modulate proinflammatory responses that can lead to immunopathogenesis. We present an extensive and systematic profiling of lipids, metabolites, and proteins in respiratory compartments of ferrets infected with either 1918 or 2009 human pandemic H1N1 influenza viruses. Integrative analysis of high-throughput omics data with virologic and histopathologic data uncovered relationships between host responses and phenotypic outcomes of viral infection. Proinflammatory lipid precursors in the trachea following 1918 infection correlated with severe tracheal lesions. Using an algorithm to infer cell quantity changes from gene expression data, we found enrichment of distinct T cell subpopulations in the trachea. There was also a predicted increase in inflammatory monocytes in the lung of 1918 virus-infected animals that was sustained throughout infection. This study presents a unique resource to the influenza research community and demonstrates the utility of an integrative systems approach for characterization of lipid metabolism alterations underlying respiratory responses to viruses. PMID:26867183

  13. Diarrheagenic Pathogens in Polymicrobial Infections

    PubMed Central

    Lindsay, Brianna; Ramamurthy, T.; Sen Gupta, Sourav; Takeda, Yoshifumi; Rajendran, Krishnan; Nair, G. Balakrish

    2011-01-01

    During systematic active surveillance of the causes of diarrhea in patients admitted to the Infectious Diseases and Beliaghata General Hospital in Kolkata, India, we looked for 26 known gastrointestinal pathogens in fecal samples from 2,748 patients. Samples from about one-third (29%) of the patients contained multiple pathogens. Polymicrobial infections frequently contained Vibrio cholerae O1 and rotavirus. When these agents were present, some co-infecting agents were found significantly less often (p = 10–5 to 10–33), some were detected significantly more often (p = 10–5 to 10–26), and others were detected equally as often as when V. cholerae O1 or rotavirus was absent. When data were stratified by patient age and season, many nonrandom associations remained statistically significant. The causes and effects of these nonrandom associations remain unknown. PMID:21470448

  14. Protection of chickens against H5N1 highly pathogenic avian influenza virus infection by live vaccination with infectious laryngotracheitis virus recombinants expressing H5 hemagglutinin and N1 neuraminidase.

    PubMed

    Pavlova, Sophia P; Veits, Jutta; Keil, Günther M; Mettenleiter, Thomas C; Fuchs, Walter

    2009-01-29

    Attenuated vaccine strains of the alphaherpesvirus causing infectious laryngotracheitis of chickens (ILTV, gallid herpesvirus 1) can be used for mass application. Previously, we showed that live virus vaccination with recombinant ILTV expressing hemagglutinin of highly pathogenic avian influenza viruses (HPAIV) protected chickens against ILT and fowl plague caused by HPAIV carrying the corresponding hemagglutinin subtypes [Lüschow D, Werner O, Mettenleiter TC, Fuchs W. Protection of chickens from lethal avian influenza A virus infection by live-virus vaccination with infectious laryngotracheitis virus recombinants expressing the hemagglutinin (H5) gene. Vaccine 2001;19(30):4249-59; Veits J, Lüschow D, Kindermann K, Werner O, Teifke JP, Mettenleiter TC, et al. Deletion of the non-essential UL0 gene of infectious laryngotracheitis (ILT) virus leads to attenuation in chickens, and UL0 mutants expressing influenza virus haemagglutinin (H7) protect against ILT and fowl plague. J Gen Virol 2003;84(12):3343-52]. However, protection against H5N1 HPAIV was not satisfactory. Therefore, a newly designed dUTPase-negative ILTV vector was used for rapid insertion of the H5-hemagglutinin, or N1-neuraminidase genes of a recent H5N1 HPAIV isolate. Compared to our previous constructs, protein expression was considerably enhanced by insertion of synthetic introns downstream of the human cytomegalovirus immediate-early promoter within the 5'-nontranslated region of the transgenes. Deletion of the viral dUTPase gene did not affect in vitro replication of the ILTV recombinants, but led to sufficient attenuation in vivo. After a single ocular immunization, all chickens developed H5- or N1-specific serum antibodies. Nevertheless, animals immunized with N1-ILTV died after subsequent H5N1 HPAIV challenge, although survival times were prolonged compared to non-vaccinated controls. In contrast, all chickens vaccinated with either H5-ILTV alone, or H5- and N1-ILTV simultaneously, survived

  15. Varicella zoster virus infection.

    PubMed

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

    2015-01-01

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

  16. Characterization of a novel single-stranded RNA virus, closely related to fusariviruses, infecting the plant pathogenic fungus Alternaria brassicicola.

    PubMed

    Zhong, Jie; Shang, Hong Hong; Zhu, Chuan Xia; Zhu, Jun Zi; Zhu, Hong Jian; Hu, Yan; Gao, Bi Da

    2016-06-01

    The alternaria blackspot of rapeseed is one of the most prominent diseases of rapeseed. It is caused by three species of the genus Alternaria: Alternaria brassicicola, Alternaria brassicae, and Alternaria raphanin. Here we report a novel positive-sense RNA virus from an A. brassicicola strain 817-14. The virus has a 6639 nucleotide (nt) long genome, excluding a poly (A)-tail, and was predicted to contain three putative open reading frames (ORF1, ORF2, and ORF3). The large ORF1 encoded a 174-kDa polyprotein (composed of 1522 amino acid residues) containing a conserved RNA-dependent RNA polymerase (RdRp) domain and a helicase domain. The other two smaller ORFs encoded polypeptides with unknown function. Homology search and phylogenetic analysis, based on the RdRp and helicase domains, suggest that this virus is related to and grouped with Sclerotinia sclerotiorum fusarivirus 1 (SsFV1), Rosellinia necatrix fusarivirus 1 (RnFV1), Fusarium graminearum virus-DK21 (FgV1), and Penicillium roqueforti RNA mycovirus 1 (PrRV1), all of which belong to a newly proposed family Fusariviridae. For this study, we designed the virus as "Alternaria brassicicola fusarivirus 1" (AbFV1). Virus elimination revealed that AbFV1 has no conspicuous impact on the biological properties of its host. PMID:26707921

  17. [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

  18. 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

  19. Pathogenicity of H5N1 HPAI viruses from Vietnam in chickens and ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ducks and other wild aquatic birds are the natural reservoir of influenza type A viruses, and influenza viruses in these species normally is an asymptomatic infection. Even the viruses that are highly pathogenic for chickens typically can infect but do not cause disease in domestic ducks. However,...

  20. The pathogenicity of H7 subtype avian influenza viruses in chickens, turkeys and ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza (AI) viruses infect numerous avian species, and low pathogenicity (LP) AI viruses of the H7 subtype are typically reported to produce mild or subclinical infections in both wild aquatic birds and domestic poultry. However relatively little work has been done to compare LPAI viruses ...

  1. Susceptibility of wood ducks (Aix sponsa) to H5N1 highly pathogenic avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since 2002, H5N1 highly pathogenic avian influenza (HPAI) viruses have caused mortality in numerous species of wild birds. Although these infections document the susceptibility of wild birds to H5N1 HPAI viruses and the spillover of these viruses from infected domestic birds to wild birds, it is un...

  2. Differences in pathogenicity, response to vaccination, and innate immune responses in different types of ducks infected with a virulent H5N1 highly pathogenic avian influenza virus from Vietnam

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wild ducks are reservoirs of avian influenza viruses in nature, and usually don’t show signs of disease. However, some Asian lineage H5N1 highly pathogenic avian influenza (HPAI) viruses can cause disease and death in both wild and domestic ducks. The objective of this study was to compare the cli...

  3. Attenuation of Pathogenic Immune Responses during Infection with Human and Simian Immunodeficiency Virus (HIV/SIV) by the Tetracycline Derivative Minocycline

    PubMed Central

    Drewes, Julia L.; Szeto, Gregory L.; Engle, Elizabeth L.; Liao, Zhaohao; Shearer, Gene M.; Zink, M. Christine; Graham, David R.

    2014-01-01

    HIV immune pathogenesis is postulated to involve two major mechanisms: 1) chronic innate immune responses that drive T cell activation and apoptosis and 2) induction of immune regulators that suppress T cell function and proliferation. Both arms are elevated chronically in lymphoid tissues of non-natural hosts, which ultimately develop AIDS. However, these mechanisms are not elevated chronically in natural hosts of SIV infection that avert immune pathogenesis despite similarly high viral loads. In this study we investigated whether minocycline could modulate these pathogenic antiviral responses in non-natural hosts of HIV and SIV. We found that minocycline attenuated in vitro induction of type I interferon (IFN) and the IFN-stimulated genes indoleamine 2,3-dioxygenase (IDO1) and TNF-related apoptosis inducing ligand (TRAIL) in human plasmacytoid dendritic cells and PBMCs exposed to aldrithiol-2 inactivated HIV or infectious influenza virus. Activation-induced TRAIL and expression of cytotoxic T-lymphocyte antigen 4 (CTLA-4) in isolated CD4+ T cells were also reduced by minocycline. Translation of these in vitro findings to in vivo effects, however, were mixed as minocycline significantly reduced markers of activation and activation-induced cell death (CD25, Fas, caspase-3) but did not affect expression of IFNβ or the IFN-stimulated genes IDO1, FasL, or Mx in the spleens of chronically SIV-infected pigtailed macaques. TRAIL expression, reflecting the mixed effects of minocycline on activation and type I IFN stimuli, was reduced by half, but this change was not significant. These results show that minocycline administered after infection may protect against aspects of activation-induced cell death during HIV/SIV immune disease, but that in vitro effects of minocycline on type I IFN responses are not recapitulated in a rapid progressor model in vivo. PMID:24732038

  4. New Carbocyclic Amino Acid Derivatives Inhibit Infection Caused by Highly Pathogenic Influenza A Virus Strain (H5N1).

    PubMed

    Shibnev, V A; Garaev, T M; Deryabin, P G; Finogenova, M P; Botikov, A G; Mishin, D V

    2016-06-01

    New amino acid derivatives with carbocycles of adamantine and quinaldic acid were synthesized and their in vitro antiviral activity against influenza A/H5N1 virus was evaluated. Experiments on cultured embryonic porcine kidney epithelial cells showed that amino acid derivatives suppressed viral replication. Tret-butyloxycarbonyl-DL-methionylsulfonyl-1-adamantayl ethylamine and benzyloxycarbonyl-L-trypthophanyl-1-adamantayl ethylamine compounds demonstrated high activity in all in vitro experiments. Moreover, some compounds showed virucidal activity against influenza A/H5N1 virus. PMID:27383164

  5. Expansion of FOXP3+ CD8 T cells with suppressive potential in colorectal mucosa following a pathogenic simian immunodeficiency virus infection correlates with diminished antiviral T cell response and viral control.

    PubMed

    Nigam, Pragati; Velu, Vijayakumar; Kannanganat, Sunil; Chennareddi, Lakshmi; Kwa, Suefen; Siddiqui, Mariam; Amara, Rama Rao

    2010-02-15

    FOXP3(+)CD8(+) T cells are present at low levels in humans; however, the function of these cells is not known. In this study, we demonstrate a rapid expansion of CD25(+)FOXP3(+)CD8(+) regulatory T cells (Tregs) in the blood and multiple tissues following a pathogenic SIV infection in rhesus macaques. The expansion was pronounced in lymphoid and colorectal mucosal tissues, preferential sites of virus replication. These CD8 Tregs expressed molecules associated with immune suppressor function such as CTLA-4 and CD39 and suppressed proliferation of SIV-specific T cells in vitro. They also expressed low levels of granzyme B and perforin, suggesting that these cells do not possess killing potential. Expansion of CD8 Tregs correlated directly with acute phase viremia and inversely with the magnitude of antiviral T cell response. Expansion was also observed in HIV-infected humans but not in SIV-infected sooty mangabeys with high viremia, suggesting a direct role for hyperimmune activation and an indirect role for viremia in the induction of these cells. These results suggest an important but previously unappreciated role for CD8 Tregs in suppressing antiviral immunity during immunodeficiency virus infections. These results also suggest that CD8 Tregs expand in pathogenic immunodeficiency virus infections in the nonnatural hosts and that therapeutic strategies that prevent expansion of these cells may enhance control of HIV infection. PMID:20053943

  6. Parainfluenza Virus Infection.

    PubMed

    Branche, Angela R; Falsey, Ann R

    2016-08-01

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

  7. Microarray analysis following infection with highly pathogenic avian influenza H5N1 virus in naive and vaccinated SPF chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza (AI) is a viral disease of poultry that remains a constant threat to commercial poultry throughout the world. Within the last few years, outbreaks of highly pathogenic avian influenza (HPAI) H5N1 have originated in Southeast Asia and spread to several European, Middle Eastern, and A...

  8. Early responses of chicken lungs and spleens to infection with highly pathogenic avian influenza virus using microarray analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Within the last few years, outbreaks of highly pathogenic avian influenza (HPAI) have originated in Asia and spread through several Middle Eastern, African and European countries, resulting in one of the most serious animal disease incident in recent history. These outbreaks were characterized by t...

  9. Highly Pathogenic Avian Influenza Virus A/H5N1 Infection in Vaccinated Meat Duck Flocks in the Mekong Delta of Vietnam.

    PubMed

    Cuong, N V; Truc, V N T; Nhung, N T; Thanh, T T; Chieu, T T B; Hieu, T Q; Men, N T; Mai, H H; Chi, H T; Boni, M F; van Doorn, H R; Thwaites, G E; Carrique-Mas, J J; Hoa, N T

    2016-04-01

    We investigated episodes of suspected highly pathogenic avian influenza (HPAI)-like illness among 12 meat duck flocks in two districts in Tien Giang province (Mekong Delta, Vietnam) in November 2013. In total, duck samples from 8 of 12 farms tested positive for HPAI virus subtype A/haemagglutinin 5 and neuraminidase 1 (H5N1) by real-time RT-PCR. Sequencing results confirmed clade of 2.3.2.1.c as the cause of the outbreaks. Most (7/8) laboratory-confirmed positive flocks had been vaccinated with inactivated HPAI H5N1 clade 2.3.4 vaccines <6 days prior to onset of clinical signs. A review of vaccination data in relation to estimated production in the area suggested that vaccination efforts were biased towards larger flocks and that vaccination coverage was low [21.2% ducks vaccinated with two shots (range by district 7.4-34.9%)]. The low-coverage data, the experimental evidence of lack of cross-protection conferred by the currently used vaccines based on clade 2.3.4 together with the short lifespan of meat duck flocks (60-70 days), suggest that vaccination is not likely to be effective as a tool for control of H5N1 infection in meat duck flocks in the area. PMID:26748550

  10. Expression of fluorescent proteins within the repeat long region of the Marek's disease virus genome allows direct identification of infected cells while retaining full pathogenicity.

    PubMed

    Jarosinski, Keith W; Donovan, Kathleen M; Du, Guixin

    2015-04-01

    Marek's disease virus (MDV) is a lymphotropic alphaherpesvirus and causes Marek's disease (MD) in chickens. RLORF4 is an MDV-specific gene located in the repeat long (RL) regions of the genome and is directly involved in attenuation. In this report, we generated recombinant (r)MDVs in which eGFP or mRFP was inserted in-frame of the 3' end of the RLORF4 gene. In vitro growth was unaffected and infected cells could be identified by using fluorescent microscopy. Interestingly, though inserted in-frame with RLORF4, eGFP and mRFP were expressed alone, confirming mRNA expression and splicing within the RL of MDV is complex. In vivo, rMDVs expressing mRFP or eGFP caused tumors similar to wild-type MDV. Fluorescent protein expression could be seen in spleen, tumor, and feather follicle epithelial cells. These results show that expression of fluorescent proteins within the RL region results in fluorescent rMDVs that still maintains full pathogenicity in the chicken. PMID:25725150

  11. Molecular Basis of Latency in Pathogenic Human Viruses

    NASA Astrophysics Data System (ADS)

    Garcia-Blanco, Mariano A.; Cullen, Bryan R.

    1991-11-01

    Several human viruses are able to latently infect specific target cell populations in vivo. Analysis of the replication cycles of herpes simplex virus, Epstein-Barr virus, and human immunodeficiency virus suggests that the latent infections established by these human pathogens primarily result from a lack of host factors critical for the expression of viral early gene products. The subsequent activation of specific cellular transcription factors in response to extracellular stimuli can induce the expression of these viral regulatory proteins and lead to a burst of lytic viral replication. Latency in these eukaryotic viruses therefore contrasts with latency in bacteriophage, which is maintained primarily by the expression of virally encoded repressors of lytic replication.

  12. Comparison of pathogenicities of H7 avian influenza viruses via intranasal and conjunctival inoculation in cynomolgus macaques.

    PubMed

    Shichinohe, Shintaro; Itoh, Yasushi; Nakayama, Misako; Ozaki, Hiroichi; Soda, Kosuke; Ishigaki, Hirohito; Okamatsu, Masatoshi; Sakoda, Yoshihiro; Kida, Hiroshi; Ogasawara, Kazumasa

    2016-06-01

    The outbreak of H7N9 low pathogenic avian influenza viruses in China has attracted attention to H7 influenza virus infection in humans. Since we have shown that the pathogenicity of H1N1 and H5N1 influenza viruses in macaques was almost the same as that in humans, we compared the pathogenicities of H7 avian influenza viruses in cynomolgus macaques via intranasal and conjunctival inoculation, which mimics natural infection in humans. H7N9 virus, as well as H7N7 highly pathogenic avian influenza virus, showed more efficient replication and higher pathogenicity in macaques than did H7N1 and H7N3 highly pathogenic avian influenza viruses. These results are different from pathogenicity in chickens as reported previously. Therefore, our results obtained in macaques help to estimate the pathogenicity of H7 avian influenza viruses in humans. PMID:26994587

  13. 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.

  14. A computationally optimized broadly reactive H5 hemagglutinin vaccine provides protection against homologous and heterologous H5N1 highly pathogenic avian influenza virus infection in chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since its emergence in 1996 in China, H5N1 highly pathogenic avian influenza (HPAI) virus has continuously evolved into different genetic clades that have created challenges to maintaining antigenically relevant H5N1 vaccine seeds. Therefore, a universal (multi-hemagglutinin [HA] subtype) or more c...

  15. Different routes of inoculation impact infectivity and pathogenesis of H5N1 high pathogenicity avian influenza virus infection in chickens and domestic ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The H5N1 type A influenza viruses classified as Qinghai-like virus (clade 2.2) are a unique lineage of type A influenza viruses with the capacity to produce significant disease and mortality in gallinaceous birds and water fowl including ducks. The objective of this study was to determine the suscep...

  16. Detection of Pathogenic Viruses in Sewage Provided Early Warnings of Hepatitis A Virus and Norovirus Outbreaks

    PubMed Central

    Hellmér, Maria; Paxéus, Nicklas; Magnius, Lars; Enache, Lucica; Arnholm, Birgitta; Johansson, Annette; Bergström, Tomas

    2014-01-01

    Most persons infected with enterically transmitted viruses shed large amounts of virus in feces for days or weeks, both before and after onset of symptoms. Therefore, viruses causing gastroenteritis may be detected in wastewater, even if only a few persons are infected. In this study, the presence of eight pathogenic viruses (norovirus, astrovirus, rotavirus, adenovirus, Aichi virus, parechovirus, hepatitis A virus [HAV], and hepatitis E virus) was investigated in sewage to explore whether their identification could be used as an early warning of outbreaks. Samples of the untreated sewage were collected in proportion to flow at Ryaverket, Gothenburg, Sweden. Daily samples collected during every second week between January and May 2013 were pooled and analyzed for detection of viruses by concentration through adsorption to milk proteins and PCR. The largest amount of noroviruses was detected in sewage 2 to 3 weeks before most patients were diagnosed with this infection in Gothenburg. The other viruses were detected at lower levels. HAV was detected between weeks 5 and 13, and partial sequencing of the structural VP1protein identified three different strains. Two strains were involved in an ongoing outbreak in Scandinavia and were also identified in samples from patients with acute hepatitis A in Gothenburg during spring of 2013. The third strain was unique and was not detected in any patient sample. The method used may thus be a tool to detect incipient outbreaks of these viruses and provide early warning before the causative pathogens have been recognized in health care. PMID:25172863

  17. Effect of statin treatments on highly pathogenic avian influenza H5N1, seasonal and H1N1pdm09 virus infections in BALB/c mice

    PubMed Central

    Kumaki, Yohichi; Morrey, John D; Barnard, Dale L

    2013-01-01

    Statins are used to control elevated cholesterol or hypercholesterolemia, but have previously been reported to have antiviral properties. Aims To show efficacy of statins in various influenza virus mouse models. Materials & methods BALB/c mice were treated intraperitoneally or orally with several types of statins (simvastatin, lovastatin, mevastatin, pitavastatin, atorvastatin or rosuvastatin) at various concentrations before or after infection with either influenza A/Duck/ MN/1525/81 H5N1 virus, influenza A/Vietnam/1203/2004 H5N1 virus, influenza A/ Victoria/3/75 H3N2 virus, influenza A/NWS/33 H1N1 virus or influenza A/CA/04/09 H1N1pdm09 virus. Results The statins administered intraperitoneally or orally at any dose did not significantly enhance the total survivors relative to untreated controls. In addition, infected mice receiving any concentration of statin were not protected against weight loss due to the infection. None of the statins significantly increased the mean day of death relative to mice in the placebo treatment group. Furthermore, the statins had relatively few ameliorative effects on lung pathology or lung weights at day 3 and 6 after virus exposure, although mice treated with simvastatin did have improved lung function as measured by arterial saturated oxygen levels in one experiment. Conclusion Statins showed relatively little efficacy in any mouse model used by any parameter tested. PMID:23420457

  18. 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) ...

  19. Zika virus infections.

    PubMed

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

    2016-05-01

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

  20. Pathogenicity comparison between highly pathogenic and NADC30-like porcine reproductive and respiratory syndrome virus.

    PubMed

    Sun, Zhe; Wang, Juan; Bai, Xiaofei; Ji, Guobiao; Yan, He; Li, Yingying; Wang, Yuzhou; Tan, Feifei; Xiao, Yan; Li, Xiangdong; Tian, Kegong

    2016-08-01

    The pathogenicity of HNjz15, an NADC30-like strain of porcine reproductive and respiratory syndrome virus (PRRSV), was investigated and compared to that of a highly pathogenic PRRSV JAX1 strain. Six-week-old pigs infected with each virus showed typical clinical symptoms, including high fever and respiratory disorders. Pigs infected with JXA1 had more-severe clinical manifestations than pigs infected with HNjz15. HNjz15 replicated in vivo with kinetics similar to those of JXA1 but induced a lower level of PRRSV-specific antibody at the beginning of virus infection. Histopathologically, JXA1 infection led to more-severe lung lesions and broader organ tropism than HNjz15 did. Different from what was observed with the previously reported NADC30-like PRRSV JL580 strain, all HNjz15-infected pigs survived until the end of the study. All of these results indicated that NADC30-like PRRSV HNjz15 is virulent to pigs but is less pathogenic than the JXA1 and JL580 PRRSV strains. PMID:27151278

  1. Giant viruses of amoebae as potential human pathogens.

    PubMed

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

    2013-01-01

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

  2. Ameobal Pathogen Mimivirus Infects Macrophages through Phagocytosis

    PubMed Central

    Ghigo, Eric; Kartenbeck, Jürgen; Lien, Pham; Pelkmans, Lucas; Capo, Christian; Mege, Jean-Louis; Raoult, Didier

    2008-01-01

    Mimivirus, or Acanthamoeba polyphaga mimivirus (APMV), a giant double-stranded DNA virus that grows in amoeba, was identified for the first time in 2003. Entry by phagocytosis within amoeba has been suggested but not demonstrated. We demonstrate here that APMV was internalized by macrophages but not by non-phagocytic cells, leading to productive APMV replication. Clathrin- and caveolin-mediated endocytosis pathways, as well as degradative endosome-mediated endocytosis, were not used by APMV to invade macrophages. Ultrastructural analysis showed that protrusions were formed around the entering virus, suggesting that macropinocytosis or phagocytosis was involved in APMV entry. Reorganization of the actin cytoskeleton and activation of phosphatidylinositol 3-kinases were required for APMV entry. Blocking macropinocytosis and the lack of APMV colocalization with rabankyrin-5 showed that macropinocytosis was not involved in viral entry. Overexpression of a dominant-negative form of dynamin-II, a regulator of phagocytosis, inhibited APMV entry. Altogether, our data demonstrated that APMV enters macrophages through phagocytosis, a new pathway for virus entry in cells. This reinforces the paradigm that intra-amoebal pathogens have the potential to infect macrophages. PMID:18551172

  3. 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...

  4. The immune response to Nipah virus infection.

    PubMed

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

    2012-09-01

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

  5. Caenorhabditis elegans as a model for intracellular pathogen infection

    PubMed Central

    Balla, Keir M.; Troemel, Emily R.

    2014-01-01

    Summary The genetically tractable nematode Caenorhabditis elegans is a convenient host for studies of pathogen infection. With the recent identification of two types of natural intracellular pathogens of C. elegans, this host now provides the opportunity to examine interactions and defence against intracellular pathogens in a whole-animal model for infection. C. elegans is the natural host for a genus of microsporidia, which comprise a phylum of fungal-related pathogens of widespread importance for agriculture and medicine. More recently, C. elegans has been shown to be a natural host for viruses related to the Nodaviridae family. Both microsporidian and viral pathogens infect the C. elegans intestine, which is composed of cells that share striking similarities to human intestinal epithelial cells. Because C. elegans nematodes are transparent, these infections provide a unique opportunity to visualize differentiated intestinal cells in vivo during the course of intracellular infection. Together, these two natural pathogens of C. elegans provide powerful systems in which to study microbial pathogenesis and host responses to intracellular infection. PMID:23617769

  6. Novel Eurasian Highly Pathogenic Avian Influenza A H5 Viruses in Wild Birds, Washington, USA, 2014

    PubMed Central

    Ip, Hon S.; Crespo, Rocio; Kohrs, Paul; DeBruyn, Paul; Mansfield, Kristin G.; Baszler, Timothy; Badcoe, Lyndon; Bodenstein, Barbara; Shearn-Bochsler, Valerie; Killian, Mary Lea; Pedersen, Janice C.; Hines, Nichole; Gidlewski, Thomas; DeLiberto, Thomas; Sleeman, Jonathan M.

    2015-01-01

    Novel Eurasian lineage avian influenza A(H5N8) virus has spread rapidly and globally since January 2014. In December 2014, H5N8 and reassortant H5N2 viruses were detected in wild birds in Washington, USA, and subsequently in backyard birds. When they infect commercial poultry, these highly pathogenic viruses pose substantial trade issues. PMID:25898265

  7. Susceptibility of swine to H5 and H7 low pathogenic avian influenza viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ability of pigs to become infected with low pathogenic avian influenza (LPAI) viruses from an avian reservoir, and then generate mammalian adaptable influenza A viruses (IAVs) is difficult to determine. Yet, it is an important link to understanding any relationship between LPAI virus ecology and...

  8. Novel Eurasian highly pathogenic influenza A H5 viruses in wild birds, Washington, USA

    USGS Publications Warehouse

    Ip, Hon S.; Torchetti, Mia Kim; Crespo, Rocio; Kohrs, Paul; DeBruyn, Paul; Mansfield, Kristin G.; Baszler, Timothy; Badcoe, Lyndon; Bodenstein, Barbara L.; Shearn-Bochsler, Valerie I.; Killian, Mary Lea; Pederson, Janice C.; Hines, Nichole; Gidlewski, Thomas; DeLiberto, Thomas; Sleeman, Jonathan M.

    2015-01-01

    Novel Eurasian lineage avian influenza A(H5N8) virus has spread rapidly and globally since January 2014. In December 2014, H5N8 and reassortant H5N2 viruses were detected in wild birds in Washington, USA, and subsequently in backyard birds. When they infect commercial poultry, these highly pathogenic viruses pose substantial trade issues.

  9. Thermal inactivation of high pathogenicity avian influenza viruses in chicken meat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High pathogenicity avian influenza (HPAI) viruses cause severe disease with high mortality in chickens and related gallinaceous poultry. Some HPAI viruses cause systemic infections and replicate to high titers in skeletal muscle fibers. To prevent transmission of these viruses through contaminate...

  10. Susceptibility of wood ducks to H5N1 highly pathogenic avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since 2002, H5N1 highly pathogenic avian influenza (HPAI) viruses have caused mortality in numerous species of wild birds; this is atypical for avian influenza virus (AIV) infections in wild birds, especially for species in the Order Anseriformes. Although these infections document the susceptibili...

  11. 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

  12. Hepatitis E virus as an emerging zoonotic pathogen

    PubMed Central

    Park, Woo-Jung; Park, Byung-Joo; Ahn, Hee-Seop; Lee, Joong-Bok; Park, Seung-Yong; Song, Chang-Seon; Lee, Sang-Won; Yoo, Han-Sang

    2016-01-01

    Hepatitis E outbreaks are a serious public health concern in developing countries. The disease causes acute infections, primarily in young adults. The mortality rate is approximately 2%; however, it can exceed 20% in pregnant women in some regions in India. The causative agent, hepatitis E virus (HEV), has been isolated from several animal species, including pigs. HEV genotypes 3 and 4 have been isolated from both humans and animals, and are recognized as zoonotic pathogens. Seroprevalence studies in animals and humans indirectly suggest that HEV infections occur worldwide. The virus is primarily transmitted to humans via undercooked animal meats in developed countries. Moreover, transfusion- and transplantation-mediated HEV infections have recently been reported. This review summarizes the general characteristics of hepatitis E, HEV infection status in animals and humans, the zoonotic transmission modes of HEV, and HEV vaccine development status. PMID:27051334

  13. Autoimmune pathogenesis in dengue virus infection.

    PubMed

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

    2006-01-01

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

  14. The Role of Carbohydrates in Infection Strategies of Enteric Pathogens

    PubMed Central

    Kato, Kentaro; Ishiwa, Akiko

    2015-01-01

    Enteric pathogens cause considerable public health concerns worldwide including tropical regions. Here, we review the roles of carbohydrates in the infection strategies of various enteric pathogens including viruses, bacteria and protozoa, which infect the epithelial lining of the human and animal intestine. At host cell entry, enteric viruses, including norovirus, recognize mainly histo-blood group antigens. At the initial step of bacterial infections, carbohydrates also function as receptors for attachment. Here, we describe the function of carbohydrates in infection by Salmonella enterica and several bacterial species that produce a variety of fimbrial adhesions. During invasion by enteropathogenic protozoa, apicomplexan parasites utilize sialic acids or sulfated glycans. Carbohydrates serve as receptors for infection by these microbes; however, their usage of carbohydrates varies depending on the microbe. On the surface of the mucosal tissues of the gastrointestinal tract, various carbohydrate moieties are present and play a crucial role in infection, representing the site of infection or route of access for most microbes. During the infection and/or invasion process of the microbes, carbohydrates function as receptors for various microbes, but they can also function as a barrier to infection. One approach to develop effective prophylactic and therapeutic antimicrobial agents is to modify the drug structure. Another approach is to modify the mode of inhibition of infection depending on the individual pathogen by using and mimicking the interactions with carbohydrates. In addition, similarities in mode of infection may also be utilized. Our findings will be useful in the development of new drugs for the treatment of enteric pathogens. PMID:25859152

  15. Laser inactivation of pathogenic viruses in water

    NASA Astrophysics Data System (ADS)

    Grishkanich, Alexander; Zhevlakov, Alexander; Kascheev, Sergey; Sidorov, Igor; Ruzankina, Julia; Yakovlev, Alexey; Mak, Andrey

    2016-03-01

    Currently there is a situation that makes it difficult to provide the population with quality drinking water for the sanitary-hygienic requirements. One of the urgent problems is the need for water disinfection. Since the emergence of microorganisms that are pathogens transmitted through water such as typhoid, cholera, etc. requires constant cleansing of waters against pathogenic bacteria. In the water treatment process is destroyed up to 98% of germs, but among the remaining can be pathogenic viruses, the destruction of which requires special handling. As a result, the conducted research the following methods have been proposed for combating harmful microorganisms: sterilization of water by laser radiation and using a UV lamp.

  16. Multiple Infections of Rodents with Zoonotic Pathogens in Austria

    PubMed Central

    Schmidt, Sabrina; Essbauer, Sandra S.; Mayer-Scholl, Anne; Poppert, Sven; Schmidt-Chanasit, Jonas; Klempa, Boris; Henning, Klaus; Schares, Gereon; Groschup, Martin H.; Spitzenberger, Friederike; Richter, Dania; Heckel, Gerald

    2014-01-01

    Abstract Rodents are important reservoirs for a large number of zoonotic pathogens. We examined the occurrence of 11 viral, bacterial, and parasitic agents in rodent populations in Austria, including three different hantaviruses, lymphocytic choriomeningitis virus, orthopox virus, Leptospira spp., Borrelia spp., Rickettsia spp., Bartonella spp., Coxiella burnetii, and Toxoplasma gondii. In 2008, 110 rodents of four species (40 Clethrionomys glareolus, 29 Apodemus flavicollis, 26 Apodemus sylvaticus, and 15 Microtus arvalis) were trapped at two rural sites in Lower Austria. Chest cavity fluid and samples of lung, spleen, kidney, liver, brain, and ear pinna skin were collected. We screened selected tissue samples for hantaviruses, lymphocytic choriomeningitis virus, orthopox viruses, Leptospira, Borrelia, Rickettsia, Bartonella spp., C. burnetii, and T. gondii by RT-PCR/PCR and detected nucleic acids of Tula hantavirus, Leptospira spp., Borrelia afzelii, Rickettsia spp., and different Bartonella species. Serological investigations were performed for hantaviruses, lymphocytic choriomeningitis virus, orthopox viruses, and Rickettsia spp. Here, Dobrava-Belgrade hantavirus-, Tula hantavirus-, lymphocytic choriomeningitis virus-, orthopox virus-, and rickettsia-specific antibodies were demonstrated. Puumala hantavirus, C. burnetii, and T. gondii were neither detected by RT-PCR/PCR nor by serological methods. In addition, multiple infections with up to three pathogens were shown in nine animals of three rodent species from different trapping sites. In conclusion, these results show that rodents in Austria may host multiple zoonotic pathogens. Our observation raises important questions regarding the interactions of different pathogens in the host, the countermeasures of the host's immune system, the impact of the host–pathogen interaction on the fitness of the host, and the spread of infectious agents among wild rodents and from those to other animals or humans. PMID

  17. The effect of NS1 gene exchange on the pathogenicity of H5N1 HPAI viruses in ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Until 2002, H5N1 highly pathogenic avian influenza (HPAI) viruses caused only mild respiratory infections in ducks. Since then, new viruses have emerged that cause systemic disease and high mortality in ducks and other waterfowl. Studies on HPAI virus pathogenicity in ducks have been limited and t...

  18. The role of NS protein in the pathogenicity of HPAI H5N1 viruses in ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Until 2002, highly pathogenic avian influenza (HPAI) H5N1 viruses caused no disease or only mild respiratory infections in ducks. Since then, new viruses have emerged that cause systemic disease and high mortality in ducks and other waterfowl. Studies on HPAI virus pathogenicity in ducks have been...

  19. Overexpression of Cytochrome c by a Recombinant Rabies Virus Attenuates Pathogenicity and Enhances Antiviral Immunity

    PubMed Central

    Pulmanausahakul, Rojjanaporn; Faber, Milosz; Morimoto, Kinjiro; Spitsin, Sergei; Weihe, Eberhard; Hooper, D. Craig; Schnell, Matthias J.; Dietzschold, Bernhard

    2001-01-01

    The pathogenicity of individual rabies virus strains appears to correlate inversely with the extent of apoptotic cell death they induce and with the expression of rabies virus glycoprotein, a major inducer of an antiviral immune response. To determine whether the induction of apoptosis by rabies virus contributes to a decreased pathogenicity by stimulating antiviral immunity, we have analyzed these parameters in tissue cultures and in mice infected with a recombinant rabies virus construct that expresses the proapoptotic protein cytochrome c. The extent of apoptosis was strongly increased in primary neuron cultures infected with the recombinant virus carrying the active cytochrome c gene [SPBN-Cyto c(+)], compared with cells infected with the recombinant virus containing the inactive cytochrome c gene [SPBN-Cyto c(−)]. Mortality in mice infected intranasally with SPBN-Cyto c(+) was substantially lower than in SPBN-Cyto c(−)-infected mice. Furthermore, virus-neutralizing antibody (VNA) titers were significantly higher in mice immunized with SPBN-Cyto c(+) at the same dose. The VNA titers induced by these recombinant viruses paralleled their protective activities against a lethal rabies virus challenge infection, with SPBN-Cyto c(+) revealing an effective dose 20 times lower than that of SPBN-Cyto c(−). The strong increase in immunogenicity, coupled with the marked reduction in pathogenicity, identifies the SPBN-Cyto c(+) construct as a candidate for a live rabies virus vaccine. PMID:11602721

  20. Orf virus infection in sheep or goats.

    PubMed

    Spyrou, V; Valiakos, G

    2015-12-14

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

  1. Modeling Dental Health Care Workers' Risk of Occupational Infection from Bloodborne Pathogens.

    ERIC Educational Resources Information Center

    Capilouto, Eli; And Others

    1990-01-01

    The brief paper offers a model which permits quantification of the dental health care workers' risk of occupationally acquiring infection from bloodborne pathogens such as human immunodeficiency virus and hepatitis B virus. The model incorporates five parameters such as the probability that any individual patient is infected and number of patients…

  2. Pathogenic Chikungunya Virus Evades B Cell Responses to Establish Persistence.

    PubMed

    Hawman, David W; Fox, Julie M; Ashbrook, Alison W; May, Nicholas A; Schroeder, Kristin M S; Torres, Raul M; Crowe, James E; Dermody, Terence S; Diamond, Michael S; Morrison, Thomas E

    2016-08-01

    Chikungunya virus (CHIKV) and related alphaviruses cause epidemics of acute and chronic musculoskeletal disease. To investigate the mechanisms underlying the failure of immune clearance of CHIKV, we studied mice infected with an attenuated CHIKV strain (181/25) and the pathogenic parental strain (AF15561), which differ by five amino acids. Whereas AF15561 infection of wild-type mice results in viral persistence in joint tissues, 181/25 is cleared. In contrast, 181/25 infection of μMT mice lacking mature B cells results in viral persistence in joint tissues, suggesting that virus-specific antibody is required for clearance of infection. Mapping studies demonstrated that a highly conserved glycine at position 82 in the A domain of the E2 glycoprotein impedes clearance and neutralization of multiple CHIKV strains. Remarkably, murine and human antibodies targeting E2 domain B failed to neutralize pathogenic CHIKV strains efficiently. Our data suggest that pathogenic CHIKV strains evade E2 domain-B-neutralizing antibodies to establish persistence. PMID:27452455

  3. Human Immunodeficiency Virus (HIV) Primary Infection

    MedlinePlus

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

  4. Determinants of pathogenicity of H5N1 highly pathogenic avian influenza viruses in ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ducks have been implicated in the dissemination and evolution of the H5N1 highly pathogenic avian influenza (HPAI) viruses. The pathogenicity of H5N1 HPAI viruses in domestic ducks has increased over time with some viruses producing 100% mortality in very short time. The determinants of pathogenic...

  5. Biologic characterization of chicken-derived H6N2 low pathogenic avian influenza viruses in chickens and ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study we biologically characterized H6N2 low pathogenicity avian influenza (LPAI) viruses by infecting chickens and ducks in order to compare adaptation of these viruses in these species. We examined the clinical signs, virus shedding, and immune response to infection in 4-week old white le...

  6. 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

  7. 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 ...

  8. Detection Of Viral And Bacterial Pathogens In Acute Respiratory Infections

    PubMed Central

    Obasi, Chidi N.; Barrett, Bruce; Brown, Roger; Vrtis, Rose; Barlow, Shari; Muller, Daniel; Gern, James

    2013-01-01

    Objectives The role of bacteria in acute respiratory illnesses (ARI) of adults and interactions with viral infections is incompletely understood. This study tested the hypothesis that bacterial co-infection during ARI adds to airway inflammation and illness severity. Methods Two groups of 97 specimens each were randomly selected from multiplex-PCR identified virus-positive and virus-negative nasal specimens obtained from adults with new onset ARI, and 40 control specimens were collected from healthy adults. All specimens were analyzed for Haemophilus influenza(HI), Moraxella catarrhalis(MC) and Streptococcus pneumonia(SP) by quantitative-PCR. General linear models tested for relationships between respiratory pathogens, biomarkers (nasal wash neutrophils and CXCL8), and ARI-severity. Results Nasal specimens from adults with ARIs were more likely to contain bacteria (37% overall; HI=28%, MC=14%, SP=7%) compared to specimens from healthy adults (5% overall; HI=0%, MC=2.5%, SP=2.5%;p<0.001). Among ARI specimens, bacteria were more likely to be detected among virus-negative specimens compared to virus-positive specimens (46% vs. 27%;p=0.0046). The presence of bacteria was significantly associated with increased CXCL8 and neutrophils, but not increased symptoms. Conclusion Pathogenic bacteria were more often detected in virus-negative ARI, and also associated with increased inflammatory biomarkers. These findings suggest the possibility that bacteria may augment virus-induced ARI and contribute to airway inflammation. Summary We tested whether bacterial pathogens were associated with ARI illness and inflammation. Bacteria were detected more often in nasal secretions during ARI, especially in samples without detectable viruses, and were associated with increased airway inflammation, but not increased symptoms. PMID:24211414

  9. Lack of Interleukin-10-Mediated Anti-Inflammatory Signals and Upregulated Interferon Gamma Production Are Linked to Increased Intestinal Epithelial Cell Apoptosis in Pathogenic Simian Immunodeficiency Virus Infection

    PubMed Central

    Pan, Diganta; Kenway-Lynch, Carys S.; Lala, Wendy; Veazey, Ronald S.; Lackner, Andrew A.; Das, Arpita

    2014-01-01

    ABSTRACT Interleukin-10 (IL-10) is an immunomodulatory cytokine that is important for maintenance of epithelial cell (EC) survival and anti-inflammatory responses (AIR). The majority of HIV infections occur through the mucosal route despite mucosal epithelium acting as a barrier to human immunodeficiency virus (HIV). Therefore, understanding the role of IL-10 in maintenance of intestinal homeostasis during HIV infection is of interest for better characterization of the pathogenesis of HIV-mediated enteropathy. We demonstrated here changes in mucosal IL-10 signaling during simian immunodeficiency virus (SIV) infection in rhesus macaques. Disruption of the epithelial barrier was manifested by EC apoptosis and loss of the tight-junction protein ZO-1. Multiple cell types, including a limited number of ECs, produced IL-10. SIV infection resulted in increased levels of IL-10; however, this was associated with increased production of mucosal gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α), suggesting that IL-10 was not able to regulate AIR. This observation was supported by the downregulation of STAT3, which is necessary to inhibit production of IFN-γ and TNF-α, and the upregulation of SOCS1 and SOCS3, which are important regulatory molecules in the IL-10-mediated AIR. We also observed internalization of the IL-10 receptor (IL-10R) in mucosal lymphocytes, which could limit cellular availability of IL-10 for signaling and contribute to the loss of a functional AIR. Collectively, these findings demonstrate that internalization of IL-10R with the resultant impact on IL-10 signaling and dysregulation of the IL-10-mediated AIR might play a crucial role in EC damage and subsequent SIV/HIV pathogenesis. IMPORTANCE Interleukin-10 (IL-10), an important immunomodulatory cytokine plays a key role to control inflammatory function and homeostasis of the gastrointestinal mucosal immune system. Despite recent advancements in the study of IL-10 and its role in HIV

  10. IFITMs restrict the replication of multiple pathogenic viruses

    PubMed Central

    Perreira, Jill M.; Chin, Christopher R.; Feeley, Eric M.; Brass, Abraham L.

    2014-01-01

    The IFITM family of proteins inhibit a growing number of pathogenic viruses, among them influenza A virus, dengue virus, hepatitis C virus, and Ebola virus. This review covers recent developments in our understanding of the IFITM’s molecular determinants, potential mechanisms of action, and impact on pathogenesis. PMID:24076421

  11. Poultry vaccination directed evolution of H9N2 low pathogenicity avian influenza viruses in Korea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Significant economic losses in the poultry industries have resulted from H9N2 low pathogenic avian influenza virus infections across North Africa, the Middle East and Asia. The present study investigated the evolutionary dynamics of H9N2 viruses circulating in Korea from 1996 to 2012. Our analysis o...

  12. Control of pathogenic effector T-cell activities in situ by PD-L1 expression on respiratory inflammatory dendritic cells during respiratory syncytial virus infection

    PubMed Central

    Yao, S; Jiang, L; Moser, EK; Jewett, LB; Wright, J; Du, J; Zhou, B; Davis, SD; Krupp, NL; Braciale, TJ; Sun, J

    2015-01-01

    Respiratory syncytial virus (RSV) infection is a leading cause of severe lower respiratory tract illness in young infants, the elderly and immunocompromised individuals. We demonstrate here that the co-inhibitory molecule programmed cell death 1 (PD-1) is selectively upregulated on T cells within the respiratory tract during both murine and human RSV infection. Importantly, the interaction of PD-1 with its ligand PD-L1 is vital to restrict the pro-inflammatory activities of lung effector T cells in situ, thereby inhibiting the development of excessive pulmonary inflammation and injury during RSV infection. We further identify that PD-L1 expression on lung inflammatory dendritic cells is critical to suppress inflammatory T-cell activities, and an interferon–STAT1–IRF1 axis is responsible for increased PD-L1 expression on lung inflammatory dendritic cells. Our findings suggest a potentially critical role of PD-L1 and PD-1 interactions in the lung for controlling host inflammatory responses and disease progression in clinical RSV infection. PMID:25465101

  13. Human Papilloma Virus Infections

    PubMed Central

    Wright, V. Cecil

    1989-01-01

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

  14. 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

  15. 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

  16. Pathogenicity of a currently circulating Chinese variant pseudorabies virus in pigs

    PubMed Central

    Yang, Qing-Yuan; Sun, Zhe; Tan, Fei-Fei; Guo, Ling-Hua; Wang, Yu-Zhou; Wang, Juan; Wang, Zhi-Yan; Wang, Li-Lin; Li, Xiang-Dong; Xiao, Yan; Tian, Ke-Gong

    2016-01-01

    AIM: To test the pathogenicity of pseudorabies virus (PRV) variant HN1201 and compare its pathogenicity with a classical PRV Fa strain. METHODS: The pathogenicity of the newly-emerging PRV variant HN1201 was evaluated by different inoculating routes, virus loads, and ages of pigs. The classical PRV Fa strain was then used to compare with HN1201 to determine pathogenicity. Clinical symptoms after virus infection were recorded daily and average daily body weight was used to measure the growth performance of pigs. At necropsy, gross pathology and histopathology were used to evaluate the severity of tissue damage caused by virus infection. RESULTS: The results showed that the efficient infection method of RPV HN1201 was via intranasal inoculation at 107 TCID50, and that the virus has high pathogenicity to 35- to 127-d old pigs. Compared with Fa strain, pigs infected with HN1201 showed more severe clinical symptoms and pathological lesions. Immunochemistry results revealed HN1201 had more abundant antigen distribution in extensive organs. CONCLUSION: All of the above results suggest that PRV variant HN1201 was more pathogenic to pigs than the classical Fa strain. PMID:26870671

  17. Microgravity Analogues of Herpes Virus Pathogenicity: Human Cytomegalovirus (hCMV) and Varicella Zoster (VZV) Infectivity in Human Tissue Like Assemblies (TLAs)

    NASA Technical Reports Server (NTRS)

    Goodwin, T. J.; McCarthy, M.; Albrecht, T.; Cohrs, R.

    2009-01-01

    The old adage we are our own worst enemies may perhaps be the most profound statement ever made when applied to man s desire for extraterrestrial exploration and habitation of Space. Consider the immune system protects the integrity of the entire human physiology and is comprised of two basic elements the adaptive or circulating and the innate immune system. Failure of the components of the adaptive system leads to venerability of the innate system from opportunistic microbes; viral, bacteria, and fungal, which surround us, are transported on our skin, and commonly inhabit the human physiology as normal and imunosuppressed parasites. The fine balance which is maintained for the preponderance of our normal lives, save immune disorders and disease, is deregulated in microgravity. Thus analogue systems to study these potential Risks are essential for our progress in conquering Space exploration and habitation. In this study we employed two known physiological target tissues in which the reactivation of hCMV and VZV occurs, human neural and lung systems created for the study and interaction of these herpes viruses independently and simultaneously on the innate immune system. Normal human neural and lung tissue analogues called tissue like assemblies (TLAs) were infected with low MOIs of approximately 2 x 10(exp -5) pfu hCMV or VZV and established active but prolonged low grade infections which spanned .7-1.5 months in length. These infections were characterized by the ability to continuously produce each of the viruses without expiration of the host cultures. Verification and quantification of viral replication was confirmed via RT_PCR, IHC, and confocal spectral analyses of the respective essential viral genomes. All host TLAs maintained the ability to actively proliferate throughout the entire duration of the experiments as is analogous to normal in vivo physiological conditions. These data represent a significant advance in the ability to study the triggering

  18. 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

  19. Pathogenicity of two Egyptian H5N1 highly pathogenic avian influenza viruses in domestic ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Domestic ducks have been implicated in the dissemination and evolution of H5N1 highly pathogenic avian influenza (HPAI) viruses. Interestingly, the pathogenicity of H5N1 HPAI viruses in domestic ducks has increased over time with some viruses producing 100% mortality in ducks. These changes in vir...

  20. Airborne transmission of H5N1 high pathogenicity avian influenza viruses during simulated home slaughter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most H5N1 human infections have occurred following exposure to H5N1 high pathogenicity avian influenza (HPAI) virus-infected poultry, especially when poultry are home slaughtered or slaughtered in live poultry markets. Previous studies have demonstrated that slaughter of clade 1 isolate A/Vietnam/1...

  1. High pathogenicity avian influenza virus in the reproductive tract of chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Infection with high pathogenicity avian influenza virus (HPAIV) has been associated with a wide range of clinical manifestations in poultry including severe depression in egg production and isolation of HPAIV from eggs laid by infected hens. To evaluate the pathobiology in the reproductive tract of...

  2. Characterization of low-pathogenicity H5N1 avian influenza viruses from North America

    USGS Publications Warehouse

    Spackman, Erica; Swayne, D.E.; Suarez, D.L.; Senne, D.A.; Pedersen, J.C.; Killian, M.L.; Pasick, J.; Handel, K.; Pillai, S.P.S.; Lee, C.-W.; Stallknecht, D.; Slemons, R.; Ip, H.S.; Deliberto, T.

    2007-01-01

    Wild-bird surveillance in North America for avian influenza (AI) viruses with a goal of early identification of the Asian H5N1 highly pathogenic AI virus has identified at least six low-pathogenicity H5N1 AI viruses between 2004 and 2006. The hemagglutinin (HA) and neuraminidase (NA) genes from all 6 H5N1 viruses and an additional 38 North American wild-bird-origin H5 subtype and 28 N1 subtype viruses were sequenced and compared with sequences available in GenBank by phylogenetic analysis. Both HA and NA were phylogenetically distinct from those for viruses from outside of North America and from those for viruses recovered from mammals. Four of the H5N1 AI viruses were characterized as low pathogenicity by standard in vivo pathotyping tests. One of the H5N1 viruses, A/MuteSwan/MI/451072-2/06, was shown to replicate to low titers in chickens, turkeys, and ducks. However, transmission of A/MuteSwan/MI/451072-2/06 was more efficient among ducks than among chickens or turkeys based on virus shed. The 50% chicken infectious dose for A/MuteSwan/MI/451072-2/06 and three other wild-waterfowl-origin H5 viruses were also determined and were between 10 5.3 and 107.5 50% egg infective doses. Finally, seven H5 viruses representing different phylogenetic clades were evaluated for their antigenic relatedness by hemagglutination inhibition assay, showing that the antigenic relatedness was largely associated with geographic origin. Overall, the data support the conclusion that North American H5 wild-bird-origin AI viruses are low-pathogenicity wild-bird-adapted viruses and are antigenically and genetically distinct from the highly pathogenic Asian H5N1 virus lineage. Copyright ?? 2007, American Society for Microbiology. All Rights Reserved.

  3. Characterization of low-pathogenicity H5N1 avian influenza viruses from North America

    USGS Publications Warehouse

    Spackman, Erica; Swayne, David E.; Suarez, David L.; Senne, Dennis A.; Pedersen, Janice C.; Killian, Mary Lea; Pasick, John; Handel, Katherine; Somanathan Pillai, Smitha; Lee, Chang-Won; Stallknecht, David; Slemons, Richard; Ip, Hon S.; Deliberto, Tom

    2007-01-01

    Wild-bird surveillance in North America for avian influenza (AI) viruses with a goal of early identification of the Asian H5N1 highly pathogenic AI virus has identified at least six low-pathogenicity H5N1 AI viruses between 2004 and 2006. The hemagglutinin (HA) and neuraminidase (NA) genes from all 6 H5N1 viruses and an additional 38 North American wild-bird-origin H5 subtype and 28 N1 subtype viruses were sequenced and compared with sequences available in GenBank by phylogenetic analysis. Both HA and NA were phylogenetically distinct from those for viruses from outside of North America and from those for viruses recovered from mammals. Four of the H5N1 AI viruses were characterized as low pathogenicity by standard in vivo pathotyping tests. One of the H5N1 viruses, A/MuteSwan/MI/451072-2/06, was shown to replicate to low titers in chickens, turkeys, and ducks. However, transmission of A/MuteSwan/MI/451072-2/06 was more efficient among ducks than among chickens or turkeys based on virus shed. The 50% chicken infectious dose for A/MuteSwan/MI/451072-2/06 and three other wild-waterfowl-origin H5 viruses were also determined and were between 105.3 and 107.5 50% egg infective doses. Finally, seven H5 viruses representing different phylogenetic clades were evaluated for their antigenic relatedness by hemagglutination inhibition assay, showing that the antigenic relatedness was largely associated with geographic origin. Overall, the data support the conclusion that North American H5 wild-bird-origin AI viruses are low-pathogenicity wild-bird-adapted viruses and are antigenically and genetically distinct from the highly pathogenic Asian H5N1 virus lineage.

  4. 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

  5. Bronchointerstitial pneumonia in guinea pigs following inoculation with H5N1 high pathogenicity avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The H5N1 high pathogenicity avian influenza (HPAI) viruses have caused widespread disease of poultry in Asia, Africa and the Middle East, and sporadic human infections. The guinea pig model has been used to study human H3N2 and H1N1 influenza viruses, but knowledge is lacking on H5N1 HPAI virus inf...

  6. Respiratory Syncytial Virus Infections

    MedlinePlus

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

  7. Variability and pathogenicity of hepatitis E virus genotype 3 variants

    PubMed Central

    Ijaz, Samreen; Tedder, Richard S.; Hogema, Boris; Zaaijer, Hans L.; Izopet, Jacques; Bradley-Stewart, Amanda; Gunson, Rory; Harvala, Heli; Kokki, Inka; Simmonds, Peter

    2015-01-01

    Infection with hepatitis E virus (HEV) can be clinically inapparent or produce symptoms and signs of hepatitis of varying severity and occasional fatality. This variability in clinical outcomes may reflect differences in host susceptibility or the presence of virally encoded determinants of pathogenicity. Analysis of complete genome sequences supports the division of HEV genotype 3 (HEV-3) variants into three major clades: 3ra comprising HEV isolates from rabbits, and 3efg and 3abchij comprising the corresponding named subtypes derived from humans and pigs. Using this framework, we investigated associations between viral genetic variability of HEV-3 in symptomatic and asymptomatic infections by comparing HEV-3 subgenomic sequences previously obtained from blood donors with those from patients presenting with hepatitis in the UK (54 blood donors, 148 hepatitis patients), the Netherlands (38 blood donors, 119 hepatitis patients), France (24 blood donors, 55 hepatitis patients) and Germany (14 blood donors, 36 hepatitis patients). In none of these countries was evidence found for a significant association between virus variants and patient group (P>0.05 Fisher's exact test). Furthermore, within a group of 123 patients in Scotland with clinically apparent HEV infections, we found no evidence for an association between variants of HEV-3 and disease severity or alanine aminotransferase level. The lack of detectable virally encoded determinants of disease outcomes in HEV-3 infection implies a more important role for host factors in its clinical phenotype. PMID:26282123

  8. Hepatitis Virus Infections in Poultry.

    PubMed

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

    2016-09-01

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

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

    PubMed Central

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

    2010-01-01

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

  10. Honey Bee Infecting Lake Sinai Viruses

    PubMed Central

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

    2015-01-01

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

  11. Honey Bee Infecting Lake Sinai Viruses.

    PubMed

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

    2015-06-01

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

  12. Immediate early responses of avian tracheal epithelial cells to infection with highly pathogenic avian influenza

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Highly pathogenic (HP) avian influenza viruses (AIV) present an on going threat to the U.S. poultry industry. In order to develop new AIV control strategies it is necessary to understand the underlying mechanism of viral infection. Because the early events of AIV infection can occur on tracheal ep...

  13. Transmissibility and Pathogenicity of Ebola Virus: A Systematic Review and Meta-analysis of Household Secondary Attack Rate and Asymptomatic Infection.

    PubMed

    Dean, Natalie E; Halloran, M Elizabeth; Yang, Yang; Longini, Ira M

    2016-05-15

    Factors affecting our ability to control an Ebola outbreak include transmissibility of the virus and the proportion of transmissions occurring asymptomatically. We performed a meta-analysis of Ebola household secondary attack rate (SAR), disaggregating by type of exposure (direct contact, no direct contact, nursing care, direct contact but no nursing care). The estimated overall household SAR is 12.5% (95% confidence interval [CI], 8.6%-16.3%). Transmission was driven by direct contact, with little transmission occurring in its absence (SAR, 0.8% [95% CI, 0%-2.3%]). The greatest risk factor was the provision of nursing care (SAR, 47.9% [95% CI, 23.3%-72.6%]). There was evidence of a decline in household SAR for direct contact between 1976 and 2014 (P = .018). We estimate that 27.1% (95% CI, 14.5%-39.6%) of Ebola infections are asymptomatic. Our findings suggest that surveillance and containment measures should be effective for controlling Ebola. PMID:26932131

  14. Rapidly Expanding Range of Highly Pathogenic Avian Influenza Viruses

    PubMed Central

    Dusek, Robert J.; Spackman, Erica

    2015-01-01

    The movement of highly pathogenic avian influenza (H5N8) virus across Eurasia and into North America and the virus’ propensity to reassort with co-circulating low pathogenicity viruses raise concerns among poultry producers, wildlife biologists, aviculturists, and public health personnel worldwide. Surveillance, modeling, and experimental research will provide the knowledge required for intelligent policy and management decisions. PMID:26079209

  15. Rapidly expanding range of highly pathogenic avian influenza viruses

    USGS Publications Warehouse

    Hall, Jeffrey S.; Dusek, Robert J.; Spackman, Erica

    2015-01-01

    The movement of highly pathogenic avian influenza (H5N8) virus across Eurasia and into North America and the virus’ propensity to reassort with co-circulating low pathogenicity viruses raise concerns among poultry producers, wildlife biologists, aviculturists, and public health personnel worldwide. Surveillance, modeling, and experimental research will provide the knowledge required for intelligent policy and management decisions.

  16. Pathogenicity of the Korean H5N8 highly pathogenic avian influenza virus in commercial domestic poultry species.

    PubMed

    Lee, Dong-Hun; Kwon, Jung-Hoon; Noh, Jin-Yong; Park, Jae-Keun; Yuk, Seong-Su; Erdene-Ochir, Tseren-Ochir; Lee, Joong-Bok; Park, Seung-Yong; Choi, In-Soo; Lee, Sang-Won; Song, Chang-Seon

    2016-01-01

    In 2014, the highly pathogenic avian influenza (HPAI) virus H5N8 triggered outbreaks in wild birds and poultry farms in South Korea. In the present study, we investigated the pathogenicity of the H5N8 HPAI virus, belonging to the clade 2.3.4.4, in different species of poultry. For this, we examined clinical signs and viral shedding levels following intranasal inoculation of the virus in 3-week-old commercial layer chickens and quails, 10-week-old Korean native chickens, and 8-week-old Muscovy ducks. Intranasal inoculation with 10(6.0) viruses at 50% egg-infective dose resulted in 100% mortality in the layer chickens (8/8) and quails (4/4), but 60% and 0% deaths in the Korean native chickens (3/5) and Muscovy ducks (0/4), respectively. In addition, transmission of the inoculated virus to contact-exposed birds was evident in all the species used in this study. Based on our results, we conclude that the H5N8 HPAI virus has lower pathogenicity and transmissibility in poultry species compared with previously reported H5N1 HPAI viruses. PMID:26814367

  17. Infection of Murine Macrophages by Salmonella enterica Serovar Heidelberg Blocks Murine Norovirus Infectivity and Virus-induced Apoptosis

    PubMed Central

    Agnihothram, Sudhakar S.; Basco, Maria D. S.; Mullis, Lisa; Foley, Steven L.; Hart, Mark E.; Sung, Kidon; Azevedo, Marli P.

    2015-01-01

    Gastroenteritis caused by bacterial and viral pathogens constitutes a major public health threat in the United States accounting for 35% of hospitalizations. In particular, Salmonella enterica and noroviruses cause the majority of gastroenteritis infections, with emergence of sporadic outbreaks and incidence of increased infections. Although mechanisms underlying infections by these pathogens have been individually studied, little is known about the mechanisms regulating co-infection by these pathogens. In this study, we utilized RAW 264.7 murine macrophage cells to investigate the mechanisms governing co-infection with S. enterica serovar Heidelberg and murine norovirus (MNV). We demonstrate that infection of RAW 264.7 cells with S. enterica reduces the replication of MNV, in part by blocking virus entry early in the virus life cycle, and inducing antiviral cytokines later in the infection cycle. In particular, bacterial infection prior to, or during MNV infection affected virus entry, whereas MNV entry remained unaltered when the virus infection preceded bacterial invasion. This block in virus entry resulted in reduced virus replication, with the highest impact on replication observed during conditions of co-infection. In contrast, bacterial replication showed a threefold increase in MNV-infected cells, despite the presence of antibiotic in the medium. Most importantly, we present evidence that the infection of MNV-infected macrophages by S. enterica blocked MNV-induced apoptosis, despite allowing efficient virus replication. This apoptosis blockade was evidenced by reduction in DNA fragmentation and absence of poly-ADP ribose polymerase (PARP), caspase 3 and caspase 9 cleavage events. Our study suggests a novel mechanism of pathogenesis whereby initial co-infection with these pathogens could result in prolonged infection by either of these pathogens or both together. PMID:26658916

  18. Infection of Murine Macrophages by Salmonella enterica Serovar Heidelberg Blocks Murine Norovirus Infectivity and Virus-induced Apoptosis.

    PubMed

    Agnihothram, Sudhakar S; Basco, Maria D S; Mullis, Lisa; Foley, Steven L; Hart, Mark E; Sung, Kidon; Azevedo, Marli P

    2015-01-01

    Gastroenteritis caused by bacterial and viral pathogens constitutes a major public health threat in the United States accounting for 35% of hospitalizations. In particular, Salmonella enterica and noroviruses cause the majority of gastroenteritis infections, with emergence of sporadic outbreaks and incidence of increased infections. Although mechanisms underlying infections by these pathogens have been individually studied, little is known about the mechanisms regulating co-infection by these pathogens. In this study, we utilized RAW 264.7 murine macrophage cells to investigate the mechanisms governing co-infection with S. enterica serovar Heidelberg and murine norovirus (MNV). We demonstrate that infection of RAW 264.7 cells with S. enterica reduces the replication of MNV, in part by blocking virus entry early in the virus life cycle, and inducing antiviral cytokines later in the infection cycle. In particular, bacterial infection prior to, or during MNV infection affected virus entry, whereas MNV entry remained unaltered when the virus infection preceded bacterial invasion. This block in virus entry resulted in reduced virus replication, with the highest impact on replication observed during conditions of co-infection. In contrast, bacterial replication showed a threefold increase in MNV-infected cells, despite the presence of antibiotic in the medium. Most importantly, we present evidence that the infection of MNV-infected macrophages by S. enterica blocked MNV-induced apoptosis, despite allowing efficient virus replication. This apoptosis blockade was evidenced by reduction in DNA fragmentation and absence of poly-ADP ribose polymerase (PARP), caspase 3 and caspase 9 cleavage events. Our study suggests a novel mechanism of pathogenesis whereby initial co-infection with these pathogens could result in prolonged infection by either of these pathogens or both together. PMID:26658916

  19. 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

  20. 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

  1. 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

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

    PubMed

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

    2016-01-01

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

  3. 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

  4. Comparison of the pathogenicity of the USDA challenge virus strain to a field strain of infectious laryngotracheitis virus.

    PubMed

    Koski, Danielle M; Predgen, Ann S; Trampel, Darrell W; Conrad, Sandra K; Narwold, Debra R; Hermann, Joseph R

    2015-07-01

    Infectious laryngotracheitis virus (ILTV) causes respiratory disease in chickens. This alphaherpesvirus infects laryngeal tracheal epithelial cells and causes outbreaks culminating in decreases in egg production, respiratory distress in chickens and mortality. There are several different vaccines to combat symptoms of the virus, including chicken embryo origin, tissue culture origin and recombinant vaccines. All vaccines licensed for use in the U.S. are tested for efficacy and potency according to U.S. federal regulation using a vaccine challenge assay involving the use of an ILT challenge virus. This challenge virus is provided to biologics companies by the Center for Veterinary Biologics (CVB), United States Department of Agriculture (USDA). The current USDA challenge virus originated from a vaccine strain and has been subjected to multiple passages in eggs, and may not represent what is currently circulating in the field. The objective of this study was to evaluate and compare the pathogenicity of USDA's challenge virus strain to the pathogenicity of a recent ILT field isolate. Using the challenge virus and various dilutions of the field isolate, clinical signs, mortality and pathology were evaluated in chickens. Results indicate that the field isolate at a 1:20 dilution is comparable in pathogenicity to the USDA challenge virus at a 1:4 dilution, and that the ILTV field isolate is a viable candidate that could be used as a challenge virus when evaluating vaccine efficacy. PMID:26050912

  5. Recombinant Vaccinia Virus: Immunization against Multiple Pathogens

    NASA Astrophysics Data System (ADS)

    Perkus, Marion E.; Piccini, Antonia; Lipinskas, Bernard R.; Paoletti, Enzo

    1985-09-01

    The coding sequences for the hepatitis B virus surface antigen, the herpes simplex virus glycoprotein D, and the influenza virus hemagglutinin were inserted into a single vaccinia virus genome. Rabbits inoculated intravenously or intradermally with this polyvalent vaccinia virus recombinant produced antibodies reactive to all three authentic foreign antigens. In addition, the feasibility of multiple rounds of vaccination with recombinant vaccinia virus was demonstrated.

  6. Pathogenicity of reassortant H5N1 highly pathogenic avian influenza viruses in domestic ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The pathogenicity of H5N1 highly pathogenic avian influenza (HPAI) viruses in domestic ducks has increased over time. These changes in virulence have been reported with viruses from countries with high population of domestic ducks, including Egypt. In order to understand which viral genes are contri...

  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. Is There Still Room for Novel Viral Pathogens in Pediatric Respiratory Tract Infections?

    PubMed Central

    Taboada, Blanca; Espinoza, Marco A.; Isa, Pavel; Aponte, Fernando E.; Arias-Ortiz, María A.; Monge-Martínez, Jesús; Rodríguez-Vázquez, Rubén; Díaz-Hernández, Fidel; Zárate-Vidal, Fernando; Wong-Chew, Rosa María; Firo-Reyes, Verónica; del Río-Almendárez, Carlos N.; Gaitán-Meza, Jesús; Villaseñor-Sierra, Alberto; Martínez-Aguilar, Gerardo; Salas-Mier, Ma. del Carmen; Noyola, Daniel E.; Pérez-Gónzalez, Luis F.; López, Susana; Santos-Preciado, José I.; Arias, Carlos F.

    2014-01-01

    Viruses are the most frequent cause of respiratory disease in children. However, despite the advanced diagnostic methods currently in use, in 20 to 50% of respiratory samples a specific pathogen cannot be detected. In this work, we used a metagenomic approach and deep sequencing to examine respiratory samples from children with lower and upper respiratory tract infections that had been previously found negative for 6 bacteria and 15 respiratory viruses by PCR. Nasal washings from 25 children (out of 250) hospitalized with a diagnosis of pneumonia and nasopharyngeal swabs from 46 outpatient children (out of 526) were studied. DNA reads for at least one virus commonly associated to respiratory infections was found in 20 of 25 hospitalized patients, while reads for pathogenic respiratory bacteria were detected in the remaining 5 children. For outpatients, all the samples were pooled into 25 DNA libraries for sequencing. In this case, in 22 of the 25 sequenced libraries at least one respiratory virus was identified, while in all other, but one, pathogenic bacteria were detected. In both patient groups reads for respiratory syncytial virus, coronavirus-OC43, and rhinovirus were identified. In addition, viruses less frequently associated to respiratory infections were also found. Saffold virus was detected in outpatient but not in hospitalized children. Anellovirus, rotavirus, and astrovirus, as well as several animal and plant viruses were detected in both groups. No novel viruses were identified. Adding up the deep sequencing results to the PCR data, 79.2% of 250 hospitalized and 76.6% of 526 ambulatory patients were positive for viruses, and all other children, but one, had pathogenic respiratory bacteria identified. These results suggest that at least in the type of populations studied and with the sampling methods used the odds of finding novel, clinically relevant viruses, in pediatric respiratory infections are low. PMID:25412469

  9. Co-infection with Multiple Respiratory Pathogens Contributes to Increased Mortality Rates in Algerian Poultry Flocks.

    PubMed

    Sid, Hicham; Benachour, Karine; Rautenschlein, Silke

    2015-09-01

    Respiratory infections are a common cause for increased mortality rates in poultry worldwide. To improve intervention strategies, circulating pathogens have to be identified and further characterized. Because of the lack of diagnostic tools, it was not known what pathogens contribute to the high mortality rates in association with respiratory disease in Algeria. Our objective was to determine if primary pathogens including Mycoplasma gallisepticum (MG), Mycoplasma synoviae (MS), avian influenza virus (AIV), infectious bronchitis virus (IBV), and avian metapneumovirus (aMPV), known to be present in neighboring countries, can also be detected in Algerian chicken and turkey flocks. Results demonstrate the circulation of the investigated pathogens in Algerian poultry flocks as multi-infections. Phylogenetic characterization of the Algerian IBV strains confirmed the circulation of nephropathogenic viruses that are different from the strains isolated in neighboring countries. This could suggest the existence of a new IBV genotype in North Africa. Additionally, we detected for the first time an aMPV subtype B field strain and avian influenza virus. Interestingly, all viral pathogens were present in co-infections with MG, which could exacerbate clinical disease. Additional pathogens may be present and should be investigated in the future. Our results suggest that multiple respiratory infections may be responsible for high mortality in Algerian poultry flocks and very probably also in other regions of the world, which demonstrates the need for the establishment of more comprehensive control strategies. PMID:26478165

  10. Immunosuppression During Influenza Virus Infection

    PubMed Central

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

    1974-01-01

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