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Sample records for african virus adapting

  1. Progressive adaptation of a Georgian isolate of African swine fever virus to vero cells leads to a gradual attenuation of virulence in swine corresponding to major changes of the viral genome

    Science.gov (United States)

    African swine fever virus (ASFV) causes a contagious and often lethal disease of feral and domestic swine. Experimental vaccines derived from naturally occurring, genetically modified or cell culture-adapted ASFV have been evaluated but no commercial vaccine is available to control African Swine Fev...

  2. Genome Sequence of African Swine Fever Virus BA71, the Virulent Parental Strain of the Nonpathogenic and Tissue-Culture Adapted BA71V.

    Directory of Open Access Journals (Sweden)

    Javier M Rodríguez

    Full Text Available The strain BA71V has played a key role in African swine fever virus (ASFV research. It was the first genome sequenced, and remains the only genome completely determined. A large part of the studies on the function of ASFV genes, viral transcription, replication, DNA repair and morphogenesis, has been performed using this model. This avirulent strain was obtained by adaptation to grow in Vero cells of the highly virulent BA71 strain. We report here the analysis of the genome sequence of BA71 in comparison with that of BA71V. They possess the smallest genomes for a virulent or an attenuated ASFV, and are essentially identical except for a relatively small number of changes. We discuss the possible contribution of these changes to virulence. Analysis of the BA71 sequence allowed us to identify new similarities among ASFV proteins, and with database proteins including two ASFV proteins that could function as a two-component signaling network.

  3. Genetic characterization of Chikungunya virus in the Central African Republic.

    Science.gov (United States)

    Desdouits, Marion; Kamgang, Basile; Berthet, Nicolas; Tricou, Vianney; Ngoagouni, Carine; Gessain, Antoine; Manuguerra, Jean-Claude; Nakouné, Emmanuel; Kazanji, Mirdad

    2015-07-01

    Chikungunya virus (CHIKV) is an alphavirus transmitted by the bite of mosquito vectors. Over the past 10 years, the virus has gained mutations that enhance its transmissibility by the Aedes albopictus vector, resulting in massive outbreaks in the Indian Ocean, Asia and Central Africa. Recent introduction of competent A. albopictus vectors into the Central African Republic (CAR) pose a threat of a Chikungunya fever (CHIKF) epidemic in this region. We undertook this study to assess the genetic diversity and background of CHIKV strains isolated in the CAR between 1975 and 1984 and also to estimate the ability of local strains to adapt to A. albopictus. Our results suggest that, local CHIKV strains have a genetic background compatible with quick adaptation to A. albopictus, as previously observed in other Central African countries. Intense surveillance of the human and vector populations is necessary to prevent or anticipate the emergence of a massive CHIKF epidemic in the CAR.

  4. Selection of Variants Utilizing Heparin Sulphate For Cell Entry When South African Territories Foot-and-Mouth Disease Virus is Adapted for Growth on Cell Culture

    Science.gov (United States)

    Foot-and-mouth disease virus (FMDV) attains entry to epithelial cells by affinity for at least four members of the integrin family of receptors. Adaptation of field isolates to grow in cultured cells is an essential step towards development of vaccines against new outbreak strains. This is made poss...

  5. Towards an improved understanding of African swine fever virus transmission

    NARCIS (Netherlands)

    Cardoso de Carvalho Ferreira, H.

    2013-01-01

    African swine fever is a haemorrhagic disease of swine caused by African swine fever virus (ASFV). Estimates of virus transmission (direct or indirect) parameters for ASFV are necessary in order to model the spread of the virus, and to design more efficient control measures. Results presented on thi

  6. [Antigenic diversity of African swine fever viruses].

    Science.gov (United States)

    Sereda, A D; Balyshev, V M

    2011-01-01

    Data on the seroimmunotypic and hemadsorbing characteristics of African swine fever virus (ASF) are summarized. According to the results of immunological sampling in pigs and those of hemagglutination inhibition test, the known ASFV strains and isolates were divided into 11 groups, 8 were characterized as seroimmunogroups having their specific reference strains. A 110-140-kD ASFV serotype-specific nonstructural major glycoprotein was identified. It is suggested that it is the glycoprotein that corresponds to the genetic engineering detected virus-specific homolog of lymphocyte membrane protein CD2, gene deletion of which results in the loss of hemadsorbing properties by ASFV.

  7. Epidemiology of African swine fever virus.

    Science.gov (United States)

    Costard, S; Mur, L; Lubroth, J; Sanchez-Vizcaino, J M; Pfeiffer, D U

    2013-04-01

    African swine fever virus used to occur primarily in Africa. There had been occasional incursions into Europe or America which apart from the endemic situation on the island of Sardinia always had been successfully controlled. But following an introduction of the virus in 2007, it now has expanded its geographical distribution into Caucasus and Eastern Europe where it has not been controlled, to date. African swine fever affects domestic and wild pig species, and can involve tick vectors. The ability of the virus to survive within a particular ecosystem is defined by the ecology of its wild host populations and the characteristics of livestock production systems, which influence host and vector species densities and interrelationships. African swine fever has high morbidity in naïve pig populations and can result in very high mortality. There is no vaccine or treatment available. Apart from stamping out and movement control, there are no control measures, thereby potentially resulting in extreme losses for producers. Prevention and control of the infection requires good understanding of its epidemiology, so that targeted measures can be instigated.

  8. African swine fever virus uses macropinocytosis to enter host cells.

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    Elena G Sánchez

    Full Text Available African swine fever (ASF is caused by a large and highly pathogenic DNA virus, African swine fever virus (ASFV, which provokes severe economic losses and expansion threats. Presently, no specific protection or vaccine against ASF is available, despite the high hazard that the continued occurrence of the disease in sub-Saharan Africa, the recent outbreak in the Caucasus in 2007, and the potential dissemination to neighboring countries, represents. Although virus entry is a remarkable target for the development of protection tools, knowledge of the ASFV entry mechanism is still very limited. Whereas early studies have proposed that the virus enters cells through receptor-mediated endocytosis, the specific mechanism used by ASFV remains uncertain. Here we used the ASFV virulent isolate Ba71, adapted to grow in Vero cells (Ba71V, and the virulent strain E70 to demonstrate that entry and internalization of ASFV includes most of the features of macropinocytosis. By a combination of optical and electron microscopy, we show that the virus causes cytoplasm membrane perturbation, blebbing and ruffles. We have also found that internalization of the virions depends on actin reorganization, activity of Na(+/H(+ exchangers, and signaling events typical of the macropinocytic mechanism of endocytosis. The entry of virus into cells appears to directly stimulate dextran uptake, actin polarization and EGFR, PI3K-Akt, Pak1 and Rac1 activation. Inhibition of these key regulators of macropinocytosis, as well as treatment with the drug EIPA, results in a considerable decrease in ASFV entry and infection. In conclusion, this study identifies for the first time the whole pathway for ASFV entry, including the key cellular factors required for the uptake of the virus and the cell signaling involved.

  9. Emergence of African swine fever virus, northwestern Iran.

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    Rahimi, Pooneh; Sohrabi, Amir; Ashrafihelan, Javad; Edalat, Rosita; Alamdari, Mehran; Masoudi, Mohammadhossein; Mostofi, Saied; Azadmanesh, Kayhan

    2010-12-01

    In 2008, African swine fever was introduced into Georgia, after which it spread to neighboring Armenia, Azerbaijan, and the Russian Federation. That same year, PCR and sequence analysis identified African swine fever virus in samples from 3 dead female wild boars in northwestern Iran. Wild boars may serve as a reservoir.

  10. African swine fever virus serotype-specific proteins are significant protective antigens for African swine fever

    Science.gov (United States)

    African swine fever (ASF) is an emerging disease threat for the swine industry worldwide. No ASF vaccine is available and progress is hindered by lack of knowledge concerning the extent of African swine fever virus (ASFV) strain diversity and the viral antigens conferring type specific protective im...

  11. The African diaspora: history, adaptation and health.

    Science.gov (United States)

    Rotimi, Charles N; Tekola-Ayele, Fasil; Baker, Jennifer L; Shriner, Daniel

    2016-12-01

    The trans-Atlantic slave trade brought millions of Africans to the New World. Advances in genomics are providing novel insights into the history and health of Africans and the diasporan populations. Recent examples reviewed here include the unraveling of substantial hunter-gatherer and 'Eurasian' admixtures across sub-Saharan Africa, expanding our understanding of ancestral African genetics; the global ubiquity of mixed ancestry; the revealing of African ancestry in Latin Americans that likely derived from the slave trade; and understanding of the ancestral backgrounds of APOL1 and LPL found to influence kidney disease and lipid levels, respectively, providing specific insights into disease etiology and health disparities.

  12. Quantification of airborne African Swine Fever virus after experimental infection

    NARCIS (Netherlands)

    Carvalho Ferreira, de H.C.; Weesendorp, E.; Quak, S.; Stegeman, J.A.; Loeffen, W.L.A.

    2013-01-01

    Knowledge on African Swine Fever (ASF) transmission routes can be useful when designing control measures against the spread of ASF virus (ASFV). Few studies have focused on the airborne transmission route, and until now no data has been available on quantities of ASF virus (ASFV) in the air. Our aim

  13. Comparative analysis of African swine fever virus genotypes and serogroups.

    Science.gov (United States)

    Malogolovkin, Alexander; Burmakina, Galina; Titov, Ilya; Sereda, Alexey; Gogin, Andrey; Baryshnikova, Elena; Kolbasov, Denis

    2015-02-01

    African swine fever virus (ASFV) causes highly lethal hemorrhagic disease among pigs, and ASFV's extreme antigenic diversity hinders vaccine development. We show that p72 ASFV phylogenetic analysis does not accurately define ASFV hemadsorption inhibition assay serogroups. Thus, conventional ASFV genotyping cannot discriminate between viruses of different virulence or predict efficacy of a specific ASFV vaccine.

  14. Putative Lineage of Novel African Usutu Virus, Central Europe

    Centers for Disease Control (CDC) Podcasts

    2015-10-15

    Sarah Gregory reads an abridged version of "Putative Lineage of Novel African Usutu Virus, Central Europe.".  Created: 10/15/2015 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 10/15/2015.

  15. Impact of host cell line adaptation on quasispecies composition and glycosylation of influenza A virus hemagglutinin.

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    Jana Verena Roedig

    Full Text Available The genome of influenza A viruses is constantly changing (genetic drift resulting in small, gradual changes in viral proteins. Alterations within antibody recognition sites of the viral membrane glycoproteins hemagglutinin (HA and neuraminidase (NA result in an antigenetic drift, which requires the seasonal update of human influenza virus vaccines. Generally, virus adaptation is necessary to obtain sufficiently high virus yields in cell culture-derived vaccine manufacturing. In this study detailed HA N-glycosylation pattern analysis was combined with in-depth pyrosequencing analysis of the virus genomic RNA. Forward and backward adaptation from Madin-Darby Canine Kidney (MDCK cells to African green monkey kidney (Vero cells was investigated for two closely related influenza A virus PR/8/34 (H1N1 strains: from the National Institute for Biological Standards and Control (NIBSC or the Robert Koch Institute (RKI. Furthermore, stability of HA N-glycosylation patterns over ten consecutive passages and different harvest time points is demonstrated. Adaptation to Vero cells finally allowed efficient influenza A virus replication in Vero cells. In contrast, during back-adaptation the virus replicated well from the very beginning. HA N-glycosylation patterns were cell line dependent and stabilized fast within one (NIBSC-derived virus or two (RKI-derived virus successive passages during adaptation processes. However, during adaptation new virus variants were detected. These variants carried "rescue" mutations on the genomic level within the HA stem region, which result in amino acid substitutions. These substitutions finally allowed sufficient virus replication in the new host system. According to adaptation pressure the composition of the virus populations varied. In Vero cells a selection for "rescue" variants was characteristic. After back-adaptation to MDCK cells some variants persisted at indifferent frequencies, others slowly diminished and even

  16. African Swine Fever Virus p72 Genotype IX in Domestic Pigs, Congo, 2009

    OpenAIRE

    2011-01-01

    African swine fever virus p72 genotype IX, associated with outbreaks in eastern Africa, is cocirculating in the Republic of the Congo with West African genotype I. Data suggest that viruses from eastern Africa are moving into western Africa, increasing the threat of outbreaks caused by novel viruses in this region.

  17. African swine fever virus p72 genotype IX in domestic pigs, Congo, 2009.

    Science.gov (United States)

    Gallardo, Carmina; Anchuelo, Raquel; Pelayo, Virginia; Poudevigne, Frédéric; Leon, Tati; Nzoussi, Jacques; Bishop, Richard; Pérez, Covadonga; Soler, Alejandro; Nieto, Raquel; Martín, Hilario; Arias, Marisa

    2011-08-01

    African swine fever virus p72 genotype IX, associated with outbreaks in eastern Africa, is cocirculating in the Republic of the Congo with West African genotype I. Data suggest that viruses from eastern Africa are moving into western Africa, increasing the threat of outbreaks caused by novel viruses in this region.

  18. African Swine Fever Virus p72 Genotype IX in Domestic Pigs, Congo, 2009

    Science.gov (United States)

    Anchuelo, Raquel; Pelayo, Virginia; Poudevigne, Frédéric; Leon, Tati; Nzoussi, Jacques; Bishop, Richard; Pérez, Covadonga; Soler, Alejandro; Nieto, Raquel; Martín, Hilario; Arias, Marisa

    2011-01-01

    African swine fever virus p72 genotype IX, associated with outbreaks in eastern Africa, is cocirculating in the Republic of the Congo with West African genotype I. Data suggest that viruses from eastern Africa are moving into western Africa, increasing the threat of outbreaks caused by novel viruses in this region. PMID:21801650

  19. Prospects for development of African swine fever virus vaccines.

    Science.gov (United States)

    Dixon, L K; Abrams, C C; Chapman, D D G; Goatley, L C; Netherton, C L; Taylor, G; Takamatsu, H H

    2013-01-01

    African swine fever virus is a large DNA virus which can cause an acute haemorrhagic fever in pigs resulting in high mortality. No vaccine is available, limiting options for control. The virus encodes up to 165 genes and virus particles are multi-layered and contain more than 50 proteins. Pigs immunised with natural low virulence isolates or attenuated viruses produced by passage in tissue culture and by targeted gene deletions can be protected against challenge with virulent viruses. CD8+ cells are required for protection induced by attenuated strain OURT88/3. Passive transfer of antibodies from immune to naïve pigs can also induce protection. Knowledge of the genome sequences of attenuated and virulent strains and targeted gene deletions from virulent strains have identified a number of virus genes involved in virulence and immune evasion. This information can be used to produce rationally attenuated vaccine strains. Virus antigens that are targets for neutralising antibodies have been identified and immunisation with these recombinant proteins has been shown to induce partial protection. However knowledge of antigens which encode the dominant protective epitopes recognised by CD8+ T cells is lacking.

  20. Adaptive Immunity to Hepatitis C Virus

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    Françoise Stoll-Keller

    2009-09-01

    Full Text Available The precise role of adaptive immune responses in the clinical outcome of HCV infection is still only partially defined. Recent studies suggest that viral-host cell interactions during the acute phase of infection are essential for viral clearance or progression into chronic HCV infection. This review focuses on different aspects of the adaptive immune responses as determinants of the different outcomes of HCV infection, clearance or persistent infection, and outlines current concepts of HCV evasion strategies. Unravelling these important mechanisms of virus-host interaction will contribute to the development of novel strategies to prevent and control HCV infection.

  1. Quantification of airborne African swine fever virus after experimental infection.

    Science.gov (United States)

    de Carvalho Ferreira, H C; Weesendorp, E; Quak, S; Stegeman, J A; Loeffen, W L A

    2013-08-30

    Knowledge on African Swine Fever (ASF) transmission routes can be useful when designing control measures against the spread of ASF virus (ASFV). Few studies have focused on the airborne transmission route, and until now no data has been available on quantities of ASF virus (ASFV) in the air. Our aim was to validate an air sampling technique for ASF virus (ASFV) that could be used to detect and quantify virus excreted in the air after experimental infection of pigs. In an animal experiment with the Brazil'78, the Malta'78 and Netherlands'86 isolates, air samples were collected at several time points. For validation of the air sampling technique, ASFV was aerosolised in an isolator, and air samples were obtained using the MD8 air scan device, which was shown to be suitable to detect ASFV. The half-life of ASFV in the air was on average 19 min when analysed by PCR, and on average 14 min when analysed by virus titration. In rooms with infected pigs, viral DNA with titres up to 10(3.2) median tissue culture infective dose equivalents (TCID50eq.)/m(3) could be detected in air samples from day 4 post-inoculation (dpi 4) until the end of the experiments, at dpi 70. In conclusion, this study shows that pigs infected with ASFV will excrete virus in the air, particularly during acute disease. This study provides the first available parameters to model airborne transmission of ASFV.

  2. Porcine leukocyte cellular subsets sensitive to African swine fever virus in vitro.

    OpenAIRE

    1984-01-01

    African swine fever virus infected most, if not all, of the macrophages (monocytes) and ca. 4% of the polymorphonuclear leukocytes from porcine peripheral blood. B and T lymphocytes, either resting or stimulated with phytohemagglutinin, lipopolysaccharide, or pokeweed mitogen, were not susceptible to the virus. All of the mitogens used inhibited African swine fever multiplication in susceptible cells. The number of virus passages in vitro and the virulence degree of the virus did not affect t...

  3. Fc receptors do not mediate African swine fever virus replication in macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Alcami, A.; Vinuela, E. (Centro de Biologia Molecular, Universidad Autonoma, Madrid (Spain))

    1991-04-01

    Titration experiments in swine macrophages have shown that African swine fever virus infectivity was not enhanced in the presence of antiviral antibodies. The early viral protein synthesis and the viral DNA replication in swine macrophages infected with virus-antibody complexes were inhibited in the presence of high doses of uv-inactivated virus, which saturated specific virus receptors, but not when Fc receptors were saturated with antibodies. These results indicate that African swine fever virus does not infect swine macrophages through Fc receptors and that the normal entry pathway through virus receptors is not bypassed by the virus-antibody complexes.

  4. No evidence of African swine fever virus replication in hard ticks

    NARCIS (Netherlands)

    de Carvalho Ferreira, Helena C; Tudela Zúquete, Sara; Wijnveld, Michiel; Weesendorp, Eefke; Jongejan, Frans; Stegeman, Arjan; Loeffen, Willie L A

    2014-01-01

    African swine fever (ASF) is caused by African swine fever virus (ASFV), a tick-borne DNA virus. Soft ticks of the genus Ornithodoros are the only biological vectors of ASFV recognized so far. Although other hard ticks have been tested for vector competence, two commonly found tick species in Europe

  5. Antiviral Role of IFITM Proteins in African Swine Fever Virus Infection

    Science.gov (United States)

    Martínez-Romero, Carles; Barrado-Gil, Lucía; Galindo, Inmaculada; García-Sastre, Adolfo; Alonso, Covadonga

    2016-01-01

    The interferon-induced transmembrane (IFITM) protein family is a group of antiviral restriction factors that impair flexibility and inhibit membrane fusion at the plasma or the endosomal membrane, restricting viral progression at entry. While IFITMs are widely known to inhibit several single-stranded RNA viruses, there are limited reports available regarding their effect in double-stranded DNA viruses. In this work, we have analyzed a possible antiviral function of IFITMs against a double stranded DNA virus, the African swine fever virus (ASFV). Infection with cell-adapted ASFV isolate Ba71V is IFN sensitive and it induces IFITMs expression. Interestingly, high levels of IFITMs caused a collapse of the endosomal pathway to the perinuclear area. Given that ASFV entry is strongly dependent on endocytosis, we investigated whether IFITM expression could impair viral infection. Expression of IFITM1, 2 and 3 reduced virus infectivity in Vero cells, with IFITM2 and IFITM3 having an impact on viral entry/uncoating. The role of IFITM2 in the inhibition of ASFV in Vero cells could be related to impaired endocytosis-mediated viral entry and alterations in the cholesterol efflux, suggesting that IFITM2 is acting at the late endosome, preventing the decapsidation stage of ASFV. PMID:27116236

  6. Antiviral Role of IFITM Proteins in African Swine Fever Virus Infection.

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    Raquel Muñoz-Moreno

    Full Text Available The interferon-induced transmembrane (IFITM protein family is a group of antiviral restriction factors that impair flexibility and inhibit membrane fusion at the plasma or the endosomal membrane, restricting viral progression at entry. While IFITMs are widely known to inhibit several single-stranded RNA viruses, there are limited reports available regarding their effect in double-stranded DNA viruses. In this work, we have analyzed a possible antiviral function of IFITMs against a double stranded DNA virus, the African swine fever virus (ASFV. Infection with cell-adapted ASFV isolate Ba71V is IFN sensitive and it induces IFITMs expression. Interestingly, high levels of IFITMs caused a collapse of the endosomal pathway to the perinuclear area. Given that ASFV entry is strongly dependent on endocytosis, we investigated whether IFITM expression could impair viral infection. Expression of IFITM1, 2 and 3 reduced virus infectivity in Vero cells, with IFITM2 and IFITM3 having an impact on viral entry/uncoating. The role of IFITM2 in the inhibition of ASFV in Vero cells could be related to impaired endocytosis-mediated viral entry and alterations in the cholesterol efflux, suggesting that IFITM2 is acting at the late endosome, preventing the decapsidation stage of ASFV.

  7. MHC adaptive divergence between closely related and sympatric African cichlids.

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    Jonatan Blais

    Full Text Available BACKGROUND: The haplochromine cichlid species assemblages of Lake Malawi and Victoria represent some of the most important study systems in evolutionary biology. Identifying adaptive divergence between closely-related species can provide important insights into the processes that may have contributed to these spectacular radiations. Here, we studied a pair of sympatric Lake Malawi species, Pseudotropheus fainzilberi and P. emmiltos, whose reproductive isolation depends on olfactory communication. We tested the hypothesis that these species have undergone divergent selection at MHC class II genes, which are known to contribute to olfactory-based mate choice in other taxa. METHODOLOGY/PRINCIPAL FINDINGS: Divergent selection on functional alleles was inferred from the higher genetic divergence at putative antigen binding sites (ABS amino acid sequences than at putatively neutrally evolving sites at intron 1, exon 2 synonymous sequences and exon 2 amino acid residues outside the putative ABS. In addition, sympatric populations of these fish species differed significantly in communities of eukaryotic parasites. CONCLUSIONS/SIGNIFICANCE: We propose that local host-parasite coevolutionary dynamics may have driven adaptive divergence in MHC alleles, influencing odor-mediated mate choice and leading to reproductive isolation. These results provide the first evidence for a novel mechanism of adaptive speciation and the first evidence of adaptive divergence at the MHC in closely related African cichlid fishes.

  8. Adaptation of an Acculturation Scale for African Refugee Women.

    Science.gov (United States)

    Johnson-Agbakwu, Crista E; Flynn, Priscilla; Asiedu, Gladys B; Hedberg, Eric; Breitkopf, Carmen Radecki

    2016-02-01

    Newly-arrived African refugees are a vulnerable group of immigrants for whom no validated acculturation measures exist. A valid measurement tool is essential to understand how acculturative processes impact health and health disparities. We adapted the Bicultural Involvement Questionnaire (BIQ) to characterize its reliability among ethnic Somali women residing in Minnesota, and Somali, Somali Bantu, and Burundian women in Arizona. Surveys were administered to 164 adult women. Analyses were conducted along socio-demographic variables of ethnicity, geographic residence, age, and length of time in the United States through t tests and one-way analysis of variance. Exploratory factor analysis was conducted on the modified BIQ. Exploratory factor analyses yielded five subscales: "Speak Native Language", "Speak English Language", "Enjoy Native Activities", "Enjoy American Activities", and "Desired Ideal Culture". The subscales of the modified BIQ possessed Cronbach's α ranging from 0.68 to 0.92, suggestive that all subscales had acceptable to excellent internal consistency. The modified BIQ maintained its psychometric properties across geographic regions of resettled Central and East African refugees.

  9. Apigenin inhibits African swine fever virus infection in vitro.

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    Hakobyan, Astghik; Arabyan, Erik; Avetisyan, Aida; Abroyan, Liana; Hakobyan, Lina; Zakaryan, Hovakim

    2016-12-01

    African swine fever virus (ASFV) is one of the most devastating diseases of domestic pigs for which no effective vaccines are available. Flavonoids, natural products isolated from plants, have been reported to have significant in vitro and in vivo antiviral activity against different viruses. Here, we tested the antiviral effect of five flavonoids on the replication of ASFV in Vero cells. Our results showed a potent, dose-dependent anti-ASFV effect of apigenin in vitro. Time-of-addition experiments revealed that apigenin was highly effective at the early stages of infection. Apigenin reduced the ASFV yield by more than 99.99 % when it was added at 1 hpi. The antiviral activity of apigenin was further investigated by evaluation of ASFV protein synthesis and viral factories. This flavonoid inhibited ASFV-specific protein synthesis and viral factory formation. ASFV-infected cells continuously treated with apigenin did not display a cytopathic effect. Further studies addressing the use of apigenin in vivo are needed.

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

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    Simões, Margarida; Martins, Carlos; Ferreira, Fernando

    2013-07-26

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

  11. Live attenuated African swine fever viruses as ideal tools to dissect the mechanisms involved in viral pathogenesis and immune protection.

    Science.gov (United States)

    Lacasta, Anna; Monteagudo, Paula L; Jiménez-Marín, Ángeles; Accensi, Francesc; Ballester, María; Argilaguet, Jordi; Galindo-Cardiel, Iván; Segalés, Joaquim; Salas, María L; Domínguez, Javier; Moreno, Ángela; Garrido, Juan J; Rodríguez, Fernando

    2015-11-20

    African swine fever virus (ASFV) is the causal agent of African swine fever, a hemorrhagic and often lethal porcine disease causing enormous economical losses in affected countries. Endemic for decades in most of the sub-Saharan countries and Sardinia, the risk of ASFV-endemicity in Europe has increased since its last introduction into Europe in 2007. Live attenuated viruses have been demonstrated to induce very efficient protective immune responses, albeit most of the time protection was circumscribed to homologous ASFV challenges. However, their use in the field is still far from a reality, mainly due to safety concerns. In this study we compared the course of the in vivo infection caused by two homologous ASFV strains: the virulent E75 and the cell cultured adapted strain E75CV1, obtained from adapting E75 to grow in the CV1 cell-line. Interestingly, the kinetics of both viruses not only differed on the clinical signs that they caused and in the virus loads found, but also in the immunological pathways activated throughout the infections. Furthermore, E75CV1 confirmed its protective potential against the homologous E75 virus challenge and allowed the demonstration of poor cross-protection against BA71, thus defining it as heterologous. The in vitro specificity of the CD8(+) T-cells present at the time of lethal challenge showed a clear activation against the homologous virus (E75) but not against BA71. These findings will be of utility for a better understanding of ASFV pathogenesis and for the rational designing of safe and efficient vaccines against this virus.

  12. [Conceptual parameters of the facial arc and articulators adapted for black Africans].

    Science.gov (United States)

    N'Dindin, A C; Djeredou, K B; N'Dindin-Guinan, B; Assi, K D

    2005-12-01

    Articulators and facial arc always used in dentistry are not adapted to African black people. Their use provokes many errors in the setting of models on articulators. In this work, authors propose facial arc and articulator parameters conceptions that are suited to black Africans.

  13. Regulation of host translational machinery by African swine fever virus.

    Directory of Open Access Journals (Sweden)

    Alfredo Castelló

    2009-08-01

    Full Text Available African swine fever virus (ASFV, like other complex DNA viruses, deploys a variety of strategies to evade the host's defence systems, such as inflammatory and immune responses and cell death. Here, we analyse the modifications in the translational machinery induced by ASFV. During ASFV infection, eIF4G and eIF4E are phosphorylated (Ser1108 and Ser209, respectively, whereas 4E-BP1 is hyperphosphorylated at early times post infection and hypophosphorylated after 18 h. Indeed, a potent increase in eIF4F assembly is observed in ASFV-infected cells, which is prevented by rapamycin treatment. Phosphorylation of eIF4E, eIF4GI and 4E-BP1 is important to enhance viral protein production, but is not essential for ASFV infection as observed in rapamycin- or CGP57380-treated cells. Nevertheless, eIF4F components are indispensable for ASFV protein synthesis and virus spread, since eIF4E or eIF4G depletion in COS-7 or Vero cells strongly prevents accumulation of viral proteins and decreases virus titre. In addition, eIF4F is not only activated but also redistributed within the viral factories at early times of infection, while eIF4G and eIF4E are surrounding these areas at late times. In fact, other components of translational machinery such as eIF2alpha, eIF3b, eIF4E, eEF2 and ribosomal P protein are enriched in areas surrounding ASFV factories. Notably, the mitochondrial network is polarized in ASFV-infected cells co-localizing with ribosomes. Thus, translation and ATP synthesis seem to be coupled and compartmentalized at the periphery of viral factories. At later times after ASFV infection, polyadenylated mRNAs disappear from the cytoplasm of Vero cells, except within the viral factories. The distribution of these pools of mRNAs is similar to the localization of viral late mRNAs. Therefore, degradation of cellular polyadenylated mRNAs and recruitment of the translation machinery to viral factories may contribute to the inhibition of host protein synthesis

  14. Critically examining language bias in the South African adaptation of the WAIS-III

    OpenAIRE

    Cheryl D Foxcroft; Susan Aston

    2006-01-01

    In response to the growing demand for a test of cognitive ability for South African adults, the Human Sciences Research Council (HSRC) adapted the Wechsler Adult Intelligence Scales, third edition (WAIS-III) for Englishspeaking South Africans. The standardisation sample included both first and second language English speakers who were either educated largely in English or Afrikaans. The purpose of this article is to critically examine the adaptation process undertaken by the HSRC when standar...

  15. Transcriptional mapping of a late gene coding for the p12 attachment protein of African swine fever virus.

    OpenAIRE

    1993-01-01

    The transcriptional characterization of the gene coding for the p12 attachment protein of the African swine fever virus is presented. The results obtained have been used to generate the first detailed transcriptional map of an African swine fever virus late gene. Novel experimental evidence indicating the existence of major differences between the mechanisms controlling the transcription of late genes in African swine fever virus and poxviruses is provided.

  16. Complete Genome Sequence of an African Swine Fever Virus Isolate from Sardinia, Italy

    Science.gov (United States)

    Torresi, Claudia; Oggiano, Annalisa; Malmberg, Maja; Iscaro, Carmen; De Mia, Gian Mario; Belák, Sándor

    2016-01-01

    Previous genetic characterization of African swine fever virus isolates from the Italian island of Sardinia, where the virus has been present since 1978, has largely been limited to a few selected genomic regions. Here, we report the complete genome sequence of the isolate 47/Ss/08 collected during an outbreak in 2008. PMID:27856577

  17. African Green Monkeys Recapitulate the Clinical Experience with Replication of Live Attenuated Pandemic Influenza Virus Vaccine Candidates

    Science.gov (United States)

    Matsuoka, Yumiko; Suguitan, Amorsolo; Orandle, Marlene; Paskel, Myeisha; Boonnak, Kobporn; Gardner, Donald J.; Feldmann, Friederike; Feldmann, Heinz; Marino, Michael; Jin, Hong; Kemble, George

    2014-01-01

    ABSTRACT Live attenuated cold-adapted (ca) H5N1, H7N3, H6N1, and H9N2 influenza vaccine viruses replicated in the respiratory tract of mice and ferrets, and 2 doses of vaccines were immunogenic and protected these animals from challenge infection with homologous and heterologous wild-type (wt) viruses of the corresponding subtypes. However, when these vaccine candidates were evaluated in phase I clinical trials, there were inconsistencies between the observations in animal models and in humans. The vaccine viruses did not replicate well and immune responses were variable in humans, even though the study subjects were seronegative with respect to the vaccine viruses before vaccination. Therefore, we sought a model that would better reflect the findings in humans and evaluated African green monkeys (AGMs) as a nonhuman primate model. The distribution of sialic acid (SA) receptors in the respiratory tract of AGMs was similar to that in humans. We evaluated the replication of wt and ca viruses of avian influenza (AI) virus subtypes H5N1, H6N1, H7N3, and H9N2 in the respiratory tract of AGMs. All of the wt viruses replicated efficiently, while replication of the ca vaccine viruses was restricted to the upper respiratory tract. Interestingly, the patterns and sites of virus replication differed among the different subtypes. We also evaluated the immunogenicity and protective efficacy of H5N1, H6N1, H7N3, and H9N2 ca vaccines. Protection from wt virus challenge correlated well with the level of serum neutralizing antibodies. Immune responses were slightly better when vaccine was delivered by both intranasal and intratracheal delivery than when it was delivered intranasally by sprayer. We conclude that live attenuated pandemic influenza virus vaccines replicate similarly in AGMs and human subjects and that AGMs may be a useful model to evaluate the replication of ca vaccine candidates. IMPORTANCE Ferrets and mice are commonly used for preclinical evaluation of influenza

  18. Quantification of African cassava mosaic virus (ACMV) and East African cassava mosaic virus (EACMV-UG) in single and mixed infected Cassava (Manihot esculenta Crantz) using quantitative PCR.

    Science.gov (United States)

    Naseem, Saadia; Winter, Stephan

    2016-01-01

    The quantity of genomic DNA-A and DNA-B of African cassava mosaic virus (ACMV) and East African cassava mosaic virus Uganda (Uganda variant, EACMV-UG) was analysed using quantitative PCR to assess virus concentrations in plants from susceptible and tolerant cultivars. The concentrations of genome components in absolute and relative quantification experiments in single and mixed viral infections were determined. Virus concentration was much higher in symptomatic leaf tissues compared to non-symptomatic leaves and corresponded with the severity of disease symptoms. In general, higher titres were recorded for EACMV-UG Ca055 compared to ACMV DRC6. The quantitative assessment also showed that the distribution of both viruses in the moderately resistant cassava cv. TMS 30572 was not different from the highly susceptible cv. TME 117. Natural mixed infections with both viruses gave severe disease symptoms. Relative quantification of virus genomes in mixed infections showed higher concentrations of EACMV-UG DNA-A compared to ACMV DNA-A, but a marked reduction of EACMV-UG DNA-B. The higher concentrations of EACMV-UG DNA-B compared to EACMV DNA-A accumulation in single infections were consistent. Since DNA-B is implicated in virus cell-to-cell spread and systemic movement, the abundance of the EACMV-UG DNA-B may be an important factor driving cassava mosaic disease epidemic.

  19. Localization of the African swine fever virus attachment protein P12 in the virus particle by immunoelectron microscopy.

    Science.gov (United States)

    Carrascosa, A L; Saastre, I; González, P; Viñuela, E

    1993-03-01

    The African swine fever virus attachment protein p12 was localized in the virion by immunoelectron microscopy. Purified virus particles were incubated, before or after different treatments, with p12-specific monoclonal antibody 24BB7 and labeled with protein A-colloidal gold. Untreated virus particles showed labeling only in lateral protrusions that followed the external virus envelope. Mild treatment of African swine fever virions with the nonionic detergent octyl-glucoside or with ethanol onto the electron microscope grid resulted in a heavier and more homogeneous labeling of the virus particles. In contrast, the release of the external virus proteins by either octyl-glucoside or Nonidet-P40 and beta-mercaptoethanol generated a subviral fraction that was not labeled by 24BB7. Preembedding, labeling, and thin-sectioning experiments confirmed that the antigenic determinant recognized by 24BB7 was localized into the external region of the virus particle but required some disruption to make it more accessible. From these results we conclude that protein p12 is situated in a layer above the virus capsid with, at least, one epitope predominantly not exposed in the virion surface; this epitope may not be related to the virus ligand-cell receptor interaction.

  20. Adaptation of a Duck Influenza A Virus in Quail

    Science.gov (United States)

    Yamada, Shinya; Shinya, Kyoko; Takada, Ayato; Ito, Toshihiro; Suzuki, Takashi; Suzuki, Yasuo; Le, Quynh Mai; Ebina, Masahito; Kasai, Noriyuki; Kida, Hiroshi; Horimoto, Taisuke; Rivailler, Pierre; Chen, Li Mei; Donis, Ruben O.

    2012-01-01

    Quail are thought to serve as intermediate hosts of influenza A viruses between aquatic birds and terrestrial birds, such as chickens, due to their high susceptibility to aquatic-bird viruses, which then adapt to replicate efficiently in their new hosts. However, does replication of aquatic-bird influenza viruses in quail similarly result in their efficient replication in humans? Using sialic acid-galactose linkage-specific lectins, we found both avian (sialic acid-α2-3-galactose [Siaα2-3Gal] linkages on sialyloligosaccharides)- and human (Siaα2-6Gal)-type receptors on the tracheal cells of quail, consistent with previous reports. We also passaged a duck H3N2 virus in quail 19 times. Sequence analysis revealed that eight mutations accumulated in hemagglutinin (HA) during these passages. Interestingly, many of the altered HA amino acids found in the adapted virus are present in human seasonal viruses, but not in duck viruses. We also found that stepwise stalk deletion of neuraminidase occurred during passages, resulting in reduced neuraminidase function. Despite some hemagglutinin mutations near the receptor binding pocket, appreciable changes in receptor specificity were not detected. However, reverse-genetics-generated viruses that possessed the hemagglutinin and neuraminidase of the quail-passaged virus replicated significantly better than the virus possessing the parent HA and neuraminidase in normal human bronchial epithelial cells, whereas no significant difference in replication between the two viruses was observed in duck cells. Further, the quail-passaged but not the original duck virus replicated in human bronchial epithelial cells. These data indicate that quail can serve as intermediate hosts for aquatic-bird influenza viruses to be transmitted to humans. PMID:22090115

  1. Adaptation of a duck influenza A virus in quail.

    Science.gov (United States)

    Yamada, Shinya; Shinya, Kyoko; Takada, Ayato; Ito, Toshihiro; Suzuki, Takashi; Suzuki, Yasuo; Le, Quynh Mai; Ebina, Masahito; Kasai, Noriyuki; Kida, Hiroshi; Horimoto, Taisuke; Rivailler, Pierre; Chen, Li Mei; Donis, Ruben O; Kawaoka, Yoshihiro

    2012-02-01

    Quail are thought to serve as intermediate hosts of influenza A viruses between aquatic birds and terrestrial birds, such as chickens, due to their high susceptibility to aquatic-bird viruses, which then adapt to replicate efficiently in their new hosts. However, does replication of aquatic-bird influenza viruses in quail similarly result in their efficient replication in humans? Using sialic acid-galactose linkage-specific lectins, we found both avian (sialic acid-α2-3-galactose [Siaα2-3Gal] linkages on sialyloligosaccharides)--and human (Siaα2-6Gal)-type receptors on the tracheal cells of quail, consistent with previous reports. We also passaged a duck H3N2 virus in quail 19 times. Sequence analysis revealed that eight mutations accumulated in hemagglutinin (HA) during these passages. Interestingly, many of the altered HA amino acids found in the adapted virus are present in human seasonal viruses, but not in duck viruses. We also found that stepwise stalk deletion of neuraminidase occurred during passages, resulting in reduced neuraminidase function. Despite some hemagglutinin mutations near the receptor binding pocket, appreciable changes in receptor specificity were not detected. However, reverse-genetics-generated viruses that possessed the hemagglutinin and neuraminidase of the quail-passaged virus replicated significantly better than the virus possessing the parent HA and neuraminidase in normal human bronchial epithelial cells, whereas no significant difference in replication between the two viruses was observed in duck cells. Further, the quail-passaged but not the original duck virus replicated in human bronchial epithelial cells. These data indicate that quail can serve as intermediate hosts for aquatic-bird influenza viruses to be transmitted to humans.

  2. Transmission rate of African swine fever virus under experimental conditions.

    Science.gov (United States)

    de Carvalho Ferreira, H C; Backer, J A; Weesendorp, E; Klinkenberg, D; Stegeman, J A; Loeffen, W L A

    2013-08-30

    African swine fever (ASF) is a highly lethal, viral disease of swine. No vaccine is available, so controlling an ASF outbreak is highly dependent on zoosanitary measures, such as stamping out infected herds and quarantining of affected areas. Information on ASF transmission parameters could allow for more efficient application of outbreak control measures. Three transmission experiments were carried out to estimate the transmission parameters of two ASF virus isolates: Malta'78 (in two doses) and Netherlands'86. Different criteria were used for onset of infectiousness of infected pigs and moment of infection of contact pigs. The transmission rate (β), estimated by a Generalized Linear Model, ranged from 0.45 to 3.63 per day. For the infectious period, a minimum as well as a maximum infectious period was determined, to account for uncertainties regarding infectiousness of persistently infected pigs. While the minimum infectious period ranged from 6 to 7 days, the average maximum infectious period ranged from approximately 20 to nearly 40 days. Estimates of the reproduction ratio (R) for the first generation of transmission ranged from 4.9 to 24.2 for the minimum infectious period and from 9.8 to 66.3 for the maximum infectious period, depending on the isolate. A first approximation of the basic reproduction ratio (R0) resulted in an estimate of 18.0 (6.90-46.9) for the Malta'78 isolate. This is the first R0 estimate of an ASFV isolate under experimental conditions. The estimates of the transmission parameters provide a quantitative insight into ASFV epidemiology and can be used for the design and evaluation of more efficient control measures.

  3. Adaptive gene amplification as an intermediate step in the expansion of virus host range.

    Directory of Open Access Journals (Sweden)

    Greg Brennan

    2014-03-01

    Full Text Available The majority of recently emerging infectious diseases in humans is due to cross-species pathogen transmissions from animals. To establish a productive infection in new host species, viruses must overcome barriers to replication mediated by diverse and rapidly evolving host restriction factors such as protein kinase R (PKR. Many viral antagonists of these restriction factors are species specific. For example, the rhesus cytomegalovirus PKR antagonist, RhTRS1, inhibits PKR in some African green monkey (AGM cells, but does not inhibit human or rhesus macaque PKR. To model the evolutionary changes necessary for cross-species transmission, we generated a recombinant vaccinia virus that expresses RhTRS1 in a strain that lacks PKR inhibitors E3L and K3L (VVΔEΔK+RhTRS1. Serially passaging VVΔEΔK+RhTRS1 in minimally-permissive AGM cells increased viral replication 10- to 100-fold. Notably, adaptation in these AGM cells also improved virus replication 1000- to 10,000-fold in human and rhesus cells. Genetic analyses including deep sequencing revealed amplification of the rhtrs1 locus in the adapted viruses. Supplying additional rhtrs1 in trans confirmed that amplification alone was sufficient to improve VVΔEΔK+RhTRS1 replication. Viruses with amplified rhtrs1 completely blocked AGM PKR, but only partially blocked human PKR, consistent with the replication properties of these viruses in AGM and human cells. Finally, in contrast to AGM-adapted viruses, which could be serially propagated in human cells, VVΔEΔK+RhTRS1 yielded no progeny virus after only three passages in human cells. Thus, rhtrs1 amplification in a minimally permissive intermediate host was a necessary step, enabling expansion of the virus range to previously nonpermissive hosts. These data support the hypothesis that amplification of a weak viral antagonist may be a general evolutionary mechanism to permit replication in otherwise resistant host species, providing a molecular foothold

  4. Detection of east/central/south African genotype of chikungunya virus in Myanmar, 2010.

    Science.gov (United States)

    Tun, Mya Myat Ngwe; Thant, Kyaw Zin; Inoue, Shingo; Nabeshima, Takeshi; Aoki, Kotaro; Kyaw, Aung Kyaw; Myint, Tin; Tar, Thi; Maung, Kay Thwe Thwe; Hayasaka, Daisuke; Morita, Kouichi

    2014-08-01

    In 2010, chikungunya virus of the East Central South African genotype was isolated from 4 children in Myanmyar who had dengue-like symptoms. Phylogenetic analysis of the E1 gene revealed that the isolates were closely related to isolates from China, Thailand, and Malaysia that harbor the A226V mutation in this gene.

  5. Genetic variation among African swine fever genotype II viruses, eastern and central Europe.

    Science.gov (United States)

    Gallardo, Carmina; Fernández-Pinero, Jovita; Pelayo, Virginia; Gazaev, Ismail; Markowska-Daniel, Iwona; Pridotkas, Gediminas; Nieto, Raquel; Fernández-Pacheco, Paloma; Bokhan, Svetlana; Nevolko, Oleg; Drozhzhe, Zhanna; Pérez, Covadonga; Soler, Alejandro; Kolvasov, Denis; Arias, Marisa

    2014-09-01

    African swine fever virus (ASFV) was first reported in eastern Europe/Eurasia in 2007. Continued spread of ASFV has placed central European countries at risk, and in 2014, ASFV was detected in Lithuania and Poland. Sequencing showed the isolates are identical to a 2013 ASFV from Belarus but differ from ASFV isolated in Georgia in 2007.

  6. African swine fever virus excretion patterns in persistently infected animals: A quantitative approach

    NARCIS (Netherlands)

    Carvalho Ferreira, de H.C.; Weesendorp, E.; Elbers, A.R.W.; Bouma, A.; Quak, S.; Stegeman, J.A.; Loeffen, W.L.A.

    2012-01-01

    The continuing circulation of African swine fever (ASF) in Russia and in the Trans-Caucasian countries has led to increased efforts in characterizing the epidemiology of ASF. For a better insight in epidemiology, quantitative data on virus excretion is required. Until now, excretion data has mainly

  7. Deletion of the thymidine kinase gene induces complete attenuation of the Georgia isolate of African swine fever virus.

    Science.gov (United States)

    Sanford, B; Holinka, L G; O'Donnell, V; Krug, P W; Carlson, J; Alfano, M; Carrillo, C; Wu, Ping; Lowe, Andre; Risatti, G R; Gladue, D P; Borca, M V

    2016-02-02

    African swine fever virus (ASFV) is the etiological agent of a contagious and often lethal viral disease of domestic pigs. There are no vaccines to control Africa swine fever (ASF). Experimental vaccines have been developed using genetically modified live attenuated ASFVs obtained by specifically deleting virus genes involved in virulence, including the thymidine kinase (TK) gene. TK has been shown to be involved in the virulence of several viruses, including ASFV. Here we report the construction of a recombinant virus (ASFV-G/V-ΔTK) obtained by deleting the TK gene in a virulent strain of ASFV Georgia adapted to replicate in Vero cells (ASFV-G/VP30). ASFV-G/P-ΔTK demonstrated decreased replication both in primary swine macrophage cell cultures and in Vero cells compared with ASFV-G/VP30. In vivo, intramuscular administration of up to 10(6) TCID50 of ASFV-G/V-ΔTK does not result in ASF disease. However, these animals are not protected when challenged with the virulent parental Georgia strain.

  8. Marburg virus infection detected in a common African bat.

    Science.gov (United States)

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

    2007-08-22

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

  9. Marburg virus infection detected in a common African bat.

    Directory of Open Access Journals (Sweden)

    Jonathan S Towner

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

  10. Complete genome analysis of hepatitis B virus in human immunodeficiency virus infected and uninfected South Africans.

    Science.gov (United States)

    Gededzha, Maemu P; Muzeze, Muxe; Burnett, Rosemary J; Amponsah-Dacosta, Edina; Mphahlele, M Jeffrey; Selabe, Selokela G

    2016-09-01

    Hepatitis B virus (HBV) and human immunodeficiency virus (HIV) infections are highly endemic in South Africa. Data on the complete genome sequences of HBV in HIV-positive patients in South Africa are scanty. This study characterized the complete HBV genome isolated from both HIV-positive and negative patients at the Dr George Mukhari Academic Hospital (DGMAH), Pretoria. Serum samples from nine (five HIV-positive and four HIV-negative) patients attending the DGMAH from 2007 to 2011 were serologically tested, amplified, and sequenced for complete genome. Phylogenetic tree was constructed using MEGA6.0. Mutations were analyzed by comparing the sequences with genotype-matched GenBank references. Eight patients were HBsAg positive, with only one from the HIV positive group being negative. Phylogenetic analysis of the complete genome sequences classified them into five genotypes; A1 (n = 4), A2 (n = 1), C1 (n = 2), D1 (n = 1), and D3 (n = 1). Deletions up to 35 nucleotides in length were identified in this study. No drug resistance mutations were identified in the P ORF, while the L217R mutation was identified in one subgenotype A2 sequence. The double (A1762T/G1764A) and triple (T1753C/A1762T/G1764A) mutations in the Basal core promoter were identified in four and two sequences, respectively. In the core region, mutation G1888A was identified in four of the subgenotype A1 sequences. In conclusion, this study has added to the limited South African data on HBV genotypes and mutations in HBV/HIV co-infected and HBV mono-infected patients, based on complete HBV genome analysis. Subgenotype A1 was predominant, and no drug-resistant mutants were detected in the study. J. Med. Virol. 88:1560-1566, 2016. © 2016 Wiley Periodicals, Inc.

  11. A Systematic Review of Literature on Culturally Adapted Obesity Prevention Interventions for African American Youth

    Science.gov (United States)

    Lofton, Saria; Julion, Wrenetha A.; McNaughton, Diane B.; Bergren, Martha Dewey; Keim, Kathryn S.

    2016-01-01

    Obesity and overweight prevalence in African American (AA) youth continues to be one of the highest of all major ethnic groups, which has led researchers to pursue culturally based approaches as a means to improve obesity prevention interventions. The purpose of this systematic review was to evaluate culturally adapted obesity prevention…

  12. FATAL ENCEPHALOMYOCARDITIS VIRUS INFECTION IN AN AFRICAN SAVANNA ELEPHANT (LOXODONTA AFRICANA) IN A FRENCH ZOO.

    Science.gov (United States)

    Lamglait, Benjamin; Joris, Antoine; Romey, Aurore; Bakkali-Kassimi, Labib; Lemberger, Karin

    2015-06-01

    A fatal case of encephalomyocarditis virus (EMCV) involving an African elephant ( Loxodonta africana ) occurred in November 2013 at the Réserve Africaine de Sigean, France. An adult female was found dead without any preliminary symptoms. Gross pathologic changes consisted of petechiae and hemorrhages on mucosae and internal organs, abundant transudate in the abdominal and pericardial cavities, and myocarditis. Histopathologic examination showed extensive degeneration and necrosis of ventricular cardiomyocytes with concurrent lymphoplasmocytic and eosinophilic infiltrate. An EMCV was isolated from several organs and considered the causative agent of the myocarditis. The same strain of virus was also isolated in rodents captured on zoo premises and considered to be the reservoir of the virus. To the authors' knowledge, this is the first EMCV case in a captive African elephant in Europe.

  13. Transmission rate of African swine fever virus under experimental conditions

    NARCIS (Netherlands)

    Carvalho Ferreira, de H.C.; Backer, J.A.; Weesendorp, E.; Klinkenberg, D.; Stegeman, J.A.; Loeffen, W.L.A.

    2013-01-01

    African swine fever (ASF) is a highly lethal, viral disease of swine. No vaccine is available, so controlling an ASF outbreak is highly dependent on zoosanitary measures, such as stamping out infected herds and quarantining of affected areas. Information on ASF transmission parameters could allow fo

  14. Antigenic profile of African horse sickness virus serotype 4 VP5 and identification of a neutralizing epitope shared with bluetongue virus and epizootic hemorrhagic disease virus

    DEFF Research Database (Denmark)

    Martinez-Torrecuadrada, J.L.; Langeveld, J.P.M.; Venteo, A.;

    1999-01-01

    African horse sickness virus (AHSV) causes a fatal disease in horses. The virus capsid is composed of a double protein layer, the outermost of which is formed by two proteins: VP2 and VP5. VP2 is known to determine the serotype of the virus and to contain the neutralizing epitopes. The biological...... immunodominant region was found in the N-terminal 330 residues of VP5, defining two antigenic regions, I (residues 151-200) and II (residues 83-120). The epitopes were further defined by PEPSCAN analysis with 12mer peptides, which determined eight antigenic sites in the N-terminal half of the molecule...

  15. Climate Change Adaptation in Urban Planning in African Cities

    DEFF Research Database (Denmark)

    Jørgensen, Gertrud; Herslund, Lise Byskov; Lund, Dorthe Hedensted;

    2014-01-01

    beginning to be aware of the task, and some time will pass before it is integrated into mainstream urban governance. This chapter is based on work in progress. It covers urban governance and planning aspects of climate change adaptation as studied in the CLUVA project (CLimate change and Urban Vulnerability...... in Africa), as well as some experiences from Denmark. Focus is on the responses and capacities of urban authorities, strengths and weaknesses of the efforts, data needs and possible ways forward. The chapter concludes that many adaptation activities are taking place in the CLUVA case cities......, but that they need integration at city level to form strategic adaptation plans. A combined rational and pragmatic approach is advisable as is involvement of stakeholders in the production of relevant knowledge...

  16. Genome rearrangement affects RNA virus adaptability on prostate cancer cells

    Directory of Open Access Journals (Sweden)

    Kendra ePesko

    2015-04-01

    Full Text Available Gene order is often highly conserved within taxonomic groups, such that organisms with rearranged genomes tend to be less fit than wildtype gene orders, and suggesting natural selection favors genome architectures that maximize fitness. But it is unclear whether rearranged genomes hinder adaptability: capacity to evolutionarily improve in a new environment. Negative-sense nonsegmented RNA viruses (order Mononegavirales have specific genome architecture: 3′ UTR – core protein genes – envelope protein genes – RNA-dependent RNA-polymerase gene – 5′ UTR. To test how genome architecture affects RNA virus evolution, we examined vesicular stomatitis virus (VSV variants with the nucleocapsid (N gene moved sequentially downstream in the genome. Because RNA polymerase stuttering in VSV replication causes greater mRNA production in upstream genes, N-gene translocation towards the 5’ end leads to stepwise decreases in N transcription, viral replication and progeny production, and also impacts the activation of type 1 interferon mediated antiviral responses. We evolved VSV gene-order variants in two prostate cancer cell lines: LNCap cells deficient in innate immune response to viral infection, and PC3 cells that mount an IFN stimulated anti-viral response to infection. We observed that gene order affects phenotypic adaptability (reproductive growth; viral suppression of immune function, especially on PC3 cells that strongly select against virus infection. Overall, populations derived from the least-fit ancestor (most-altered N position architecture adapted fastest, consistent with theory predicting populations with low initial fitness should improve faster in evolutionary time. Also, we observed correlated responses to selection, where viruses improved across both hosts, rather than suffer fitness trade-offs on unselected hosts. Whole genomics revealed multiple mutations in evolved variants, some of which were conserved across selective

  17. Climate Change Adaptation in Urban Planning in African Cities

    DEFF Research Database (Denmark)

    Jørgensen, Gertrud; Herslund, Lise Byskov; Lund, Dorthe Hedensted

    2014-01-01

    beginning to be aware of the task, and some time will pass before it is integrated into mainstream urban governance. This chapter is based on work in progress. It covers urban governance and planning aspects of climate change adaptation as studied in the CLUVA project (CLimate change and Urban Vulnerability......Resilience of urban structures towards impacts of a changing climate is one of the emerging tasks that cities all over the world are facing at present. Effects of climate change take many forms, depending on local climate, spatial patterns, and socioeconomic structures. Cities are only just...... in Africa), as well as some experiences from Denmark. Focus is on the responses and capacities of urban authorities, strengths and weaknesses of the efforts, data needs and possible ways forward. The chapter concludes that many adaptation activities are taking place in the CLUVA case cities...

  18. Host coevolution alters the adaptive landscape of a virus

    Science.gov (United States)

    2016-01-01

    The origin of new and complex structures and functions is fundamental for shaping the diversity of life. Such key innovations are rare because they require multiple interacting changes. We sought to understand how the adaptive landscape led to an innovation whereby bacteriophage λ evolved the new ability to exploit a receptor, OmpF, on Escherichia coli cells. Previous work showed that this ability evolved repeatedly, despite requiring four mutations in one virus gene. Here, we examine how this innovation evolved by studying six intermediate genotypes of λ isolated during independent transitions to exploit OmpF and comparing them to their ancestor. All six intermediates showed large increases in their adsorption rates on the ancestral host. Improvements in adsorption were offset, in large part, by the evolution of host resistance, which occurred by reduced expression of LamB, the usual receptor for λ. As a consequence of host coevolution, the adaptive landscape of the virus changed such that selection favouring four of the six virus intermediates became stronger after the host evolved resistance, thereby accelerating virus populations along the path to using the new OmpF receptor. This dependency of viral fitness on host genotype thus shows an important role for coevolution in the origin of the new viral function. PMID:27683370

  19. Adaptive immune response during hepatitis C virus infection.

    Science.gov (United States)

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

    2014-04-07

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

  20. Detection of novel sequences related to african Swine Fever virus in human serum and sewage.

    Science.gov (United States)

    Loh, Joy; Zhao, Guoyan; Presti, Rachel M; Holtz, Lori R; Finkbeiner, Stacy R; Droit, Lindsay; Villasana, Zoilmar; Todd, Collin; Pipas, James M; Calgua, Byron; Girones, Rosina; Wang, David; Virgin, Herbert W

    2009-12-01

    The family Asfarviridae contains only a single virus species, African swine fever virus (ASFV). ASFV is a viral agent with significant economic impact due to its devastating effects on populations of domesticated pigs during outbreaks but has not been reported to infect humans. We report here the discovery of novel viral sequences in human serum and sewage which are clearly related to the asfarvirus family but highly divergent from ASFV. Detection of these sequences suggests that greater genetic diversity may exist among asfarviruses than previously thought and raises the possibility that human infection by asfarviruses may occur.

  1. Predicting antigenic sites on the foot-and-mouth disease virus capsid of the South African Territories (SAT) types using virus neutralization data

    Science.gov (United States)

    Foot-and-mouth disease virus (FMDV) outer capsid proteins 1B, 1C and 1D contribute to the virus serotype distribution and antigenic variants that exist within each of the seven serotypes. This study presents a phylogenetic, genetic and antigenic analysis of the South African Territories (SAT) seroty...

  2. Fitness seascapes and adaptive evolution of the influenza virus

    Science.gov (United States)

    Lassig, Michael

    2014-03-01

    The seasonal human influenza A virus undergoes rapid genome evolution. This process is triggered by interactions with the host immune system and produces significant year-to-year sequence turnover in the population of circulating viral strains. We develop a dynamical fitness model that predicts the evolution of the viral population from one year to the next. Two factors are shown to determine the fitness of a viral strain: adaptive changes, which are under positive selection, and deleterious mutations, which affect conserved viral functions such as protein stability. Combined with the influenza strain tree, this fitness model maps the adaptive history of influenza A. We discuss the implications of our results for the statistical theory of adaptive evolution in asexual populations. Based on this and related systems, we touch upon the fundamental question of when evolution can be predicted. Joint work with Marta Luksza, Columbia University.

  3. Critically examining language bias in the South African adaptation of the WAIS-III

    Directory of Open Access Journals (Sweden)

    Cheryl D Foxcroft

    2006-04-01

    Full Text Available In response to the growing demand for a test of cognitive ability for South African adults, the Human Sciences Research Council (HSRC adapted the Wechsler Adult Intelligence Scales, third edition (WAIS-III for Englishspeaking South Africans. The standardisation sample included both first and second language English speakers who were either educated largely in English or Afrikaans. The purpose of this article is to critically examine the adaptation process undertaken by the HSRC when standardising the WAIS-III for English-speaking South Africans by deliberating whether sufficient attention was paid to establishing if the measure was equivalent for various groups of English first and second language test-takers. In performing this critical examination, international test adaptation guidelines and standards, psychometric conventions, and national and international research findings were contemplated. The general conclusion reached was that the equivalence of the WAIS-III across diverse language groups has not been unequivocally established and there are indications that some bias may exist for English second language test-takers, especially if they are black or Afrikaans-speaking. Based on these conclusions, recommendations are made regarding the way forward.

  4. African swine fever virus excretion patterns in persistently infected animals: a quantitative approach.

    Science.gov (United States)

    de Carvalho Ferreira, H C; Weesendorp, E; Elbers, A R W; Bouma, A; Quak, S; Stegeman, J A; Loeffen, W L A

    2012-12-07

    The continuing circulation of African swine fever (ASF) in Russia and in the Trans-Caucasian countries has led to increased efforts in characterizing the epidemiology of ASF. For a better insight in epidemiology, quantitative data on virus excretion is required. Until now, excretion data has mainly focused on the initial stages of the disease. In our study we have studied ASF virus (ASFV) excretion dynamics in persistently infected animals. For this purpose, virus excretion through different routes was quantified over 70 days after infection. Three virus isolates of moderate virulence were used: the Brazil'78, the Malta'78 (a low and a high inoculation dose) and the Netherlands'86 isolate. For each isolate or dose, 10 animals were used. All (Brazil'78 group), or three animals per group were inoculated and the other animals served as contact animals. It was shown that dose (Malta'78 low or high) or infection route (inoculated or naturally infected) did not influence the ASFV excretion (p>0.05). Nasal, ocular and vaginal excretions showed the lowest ASFV titres. Virus was consistently present in the oropharyngeal swabs, showing two peaks, for up to 70 days. Virus was occasionally present in the faeces, occasionally with very high titres. Viral DNA persisted in blood for up to 70 days. The results presented in this study show that a high proportion of persistently infected animals shed virus into the environment for at least 70 days, representing a possible risk for transmission and that should be considered in future epidemiological analysis of ASF.

  5. First molecular assessment of the African swine fever virus status of Ornithodoros ticks from Swaziland

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    Carin I. Boshoff

    2014-02-01

    Full Text Available African swine fever (ASF is an economically significant haemorrhagic disease of domestic pigs. It is caused by the African swine fever virus (ASFV, a deoxyribonucleic acid (DNAarbovirus. Argasid ticks of the genus Ornithodoros, which are widely distributed throughout southern Africa, play a primary role in virus maintenance and spread within the endemic sylvatic cycle. The ASF status of Swaziland is unknown, but this land-locked country is surrounded by ASF-positive countries, has a burgeoning pig industry and sylvatic cycle hosts present within its borders. In this first assessment of ASF status, warthog burrows in seven nature reserves and game management areas in Swaziland were investigated for tick and virus presence. Tick infestation rates of between 33.3% – 88.8% were recovered for the four Ornithodoros-infested reserves. A total of 562 ticks were screened for virus genome presence using a duplex Polymerase Chain Reaction (PCR that targets the C-terminal end of the p72 gene of the ASFV and confirms DNA integrity through amplification of the 16S rRNA tick host gene. All samples were negative for virus genome presence and positive for the tick genome target. Nucleotide sequencing of the latter confirmed that Ornithodoros ticks from Swaziland are identical to those from the Kruger National Park in South Africa across the gene region characterised. Whilst this first evaluation of ASF presence in Swaziland indicates that the virus does not appear to be present in the key virus vector, the presence of sylvatic cycle hosts, together with the country’s proximity to ASF-affected countries calls for expanded investigations and regular monitoring of the ASF status of Swaziland.

  6. First molecular assessment of the African swine fever virus status of Ornithodoros ticks from Swaziland.

    Science.gov (United States)

    Boshoff, Carin I; Bastos, Armanda D S; Dube, Mzwandi M; Heath, Livio

    2014-12-03

    African swine fever (ASF) is an economically significant haemorrhagic disease of domestic pigs. It is caused by the African swine fever virus (ASFV), a deoxyribonucleic acid (DNA)arbovirus. Argasid ticks of the genus Ornithodoros, which are widely distributed throughout southern Africa, play a primary role in virus maintenance and spread within the endemic sylvatic cycle. The ASF status of Swaziland is unknown, but this land-locked country is surrounded by ASF-positive countries, has a burgeoning pig industry and sylvatic cycle hosts present within its borders. In this first assessment of ASF status, warthog burrows in seven nature reserves and game management areas in Swaziland were investigated for tick and virus presence. Tick infestation rates of between 33.3% - 88.8% were recovered for the four Ornithodoros-infested reserves. A total of 562 ticks were screened for virus genome presence using a duplex Polymerase Chain Reaction (PCR) that targets the C-terminal end of the p72 gene of the ASFV and confirms DNA integrity through amplification of the 16S rRNA tick host gene. All samples were negative for virus genome presence and positive for the tick genome target. Nucleotide sequencing of the latter confirmed that Ornithodoros ticks from Swaziland are identical to those from the Kruger National Park in South Africa across the gene region characterised. Whilst this first evaluation of ASF presence in Swaziland indicates that the virus does not appear to be present in the key virus vector, the presence of sylvatic cycle hosts, together with the country's proximity to ASF-affected countries calls for expanded investigations and regular monitoring of the ASF status of Swaziland.

  7. Pediatric Human Immunodeficiency Virus Screening in an African District Hospital

    OpenAIRE

    De Baets, A. J.; Edidi, B. S.; Kasali, M. J.; Beelaert, G.; Schrooten, W.; Litzroth, A; Kolsteren, P; Denolf, D.; Fransen, K

    2005-01-01

    In order to evaluate alternative tests and strategies to simplify pediatric human immunodeficiency virus (HIV) screening at the district hospital level, a cross-sectional exploratory study was organized in the Democratic Republic of the Congo. Venous and capillary phlebotomies were performed on 941 Congolese children, aged 1 month to 12 years (153 children under 18 months and 788 children more than 18 months old). The HIV prevalence rate was 4.7%. An algorithm for children more than 18 months...

  8. Crosstalk between innate and adaptive immunity inhepatitis B virus infection

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Hepatitis B virus (HBV) infection is a major public health problem worldwide. HBV is not directly cytotoxic toinfected hepatocytes; the clinical outcome of infectionresults from complicated interactions between the virusand the host immune system. In acute HBV infection,initiation of a broad, vigorous immune response is responsiblefor viral clearance and self-limited inflammatoryliver disease. Effective and coordinated innate andadaptive immune responses are critical for viral clearanceand the development of long-lasting immunity. Chronichepatitis B patients fail to mount efficient innate andadaptive immune responses to the virus. In particular,HBV-specific cytotoxic T cells, which are crucial for HBVclearance, are hyporesponsiveness to HBV infection.Accumulating experimental evidence obtained fromthe development of animal and cell line models hashighlighted the importance of innate immunity in theearly control of HBV spread. The virus has evolvedimmune escape strategies, with higher HBV loads andHBV protein concentrations associated with increasingimpairment of immune function. Therefore, treatmentof HBV infection requires inhibition of HBV replicationand protein expression to restore the suppressedhost immunity. Complicated interactions exist notonly between innate and adaptive responses, but alsoamong innate immune cells and different components ofadaptive responses. Improved insight into these complexinteractions are important in designing new therapeuticstrategies for the treatment HBV infection. In thisreview, we summarize the current knowledge regardingthe cross-talk between the innate and adaptive immuneresponses and among different immunocytes in HBVinfection.

  9. African swine fever virus introduction into the EU in 2014: Experience of Latvia.

    Science.gov (United States)

    Oļševskis, Edvīns; Guberti, Vittorio; Seržants, Mārtiņš; Westergaard, Jørgen; Gallardo, Carmina; Rodze, Ieva; Depner, Klaus

    2016-04-01

    African swine fever (ASF) virus was introduced in Latvia in June 2014. Thirty-two outbreaks in domestic pigs and 217 cases in wild boar were notified in 2014. Twenty-eight outbreaks (87.5%) were primary outbreaks. The contagiosity within pig herds was low. Failure to use simple biosecurity measures to reduce the chance of virus introduction, for example by inadvertent feeding of locally produced virus contaminated fodder were the main causes for the outbreaks in backyard holdings. The infection in wild boar survived locally in two different areas with a low prevalence and a slow spread. The persistence of the infection in wild boar within an area was most probably linked to wild boar scavenging the carcasses of infected wild boar.

  10. Lessons learned in developing a culturally adapted intervention for African-American families coping with parental cancer.

    Science.gov (United States)

    Davey, Maureen P; Kissil, Karni; Lynch, Laura; Harmon, La-Rhonda; Hodgson, Nancy

    2012-12-01

    Prior clinical research supports the effectiveness of cancer support groups for cancer patients and their families, yet African-American families continue to be underrepresented in cancer support groups and in cancer clinical research studies. In order to fill this gap, we developed and evaluated a culturally adapted family support group for African-American families coping with parental cancer. We encountered unexpected challenges in overcoming barriers to recruitment, partnering with oncology providers, and building trust with the African-American community and African-American families coping with parental cancer. We describe actions taken during the two phases of this study and lessons learned along the way about recruiting and engaging African-American families in cancer support group studies, partnering with oncology providers, networking with the African-American community, and the importance of demonstrating cultural sensitivity to overcome the understandable historical legacy of mistrust.

  11. First detection of viruses in Africanized honey bees from Peru

    Institute of Scientific and Technical Information of China (English)

    Orlando; Yaez; Graciano; Tejada; Peter; Neumann

    2014-01-01

    <正>Dear Editor,The ability of the Western honey bee,Apis mellifera,to adapt to most climates of the world and the ongoing standardization of colony management has made this species of honey bees the most important species for crop pollination.In recent years,Peru emerged as a main exporter of industrial crops.This industry is mainly concentrated in the Peruvian coastal region,because the local climate permits off-season production

  12. Development of a Luminex-Based DIVA Assay for Serological Detection of African Horse Sickness Virus in Horses.

    Science.gov (United States)

    Sánchez-Matamoros, A; Nieto-Pelegrín, E; Beck, C; Rivera-Arroyo, B; Lecollinet, S; Sailleau, C; Zientara, S; Sánchez-Vizcaíno, J M

    2016-08-01

    African horse sickness (AHS) is considered a fatal re-emergent vector-borne disease of horses. In the absence of any effective treatment for AHS, vaccination remains the most effective form of disease control. The new generation of vaccines, such as one based on purified, inactivated AHS virus (AHSV, serotype 4), which does not induce antibodies against non-structural protein 3 (NS3), enables the development of diagnostic methods that differentiate infected from vaccinated animals (DIVA assays). As detecting AHS in AHSV-free countries may lead to restrictions on international animal movements and thereby cause significant economic damage, these DIVA assays are crucial for reducing movement restrictions. In this article, we describe a Luminex-based multiplex assay for DIVA diagnosis of AHS, and we validate it in a duplex format to detect antibodies against structural protein 7 (VP7) and NS3 in serum samples from horses vaccinated with inactivated AHSV4 vaccine or infected with a live virus of the same serotype. Results of the Luminex-based assay for detecting anti-NS3 antibodies showed good positive correlation with results from an in-house enzyme-linked immunosorbent assay (ELISA). Thus, the Luminex-based technique described here may allow multiplex DIVA antibody detection in a single sample in less than 2 h, and it may prove adaptable for the development of robust, multiplex serological assays.

  13. Detailed analysis of the African green monkey model of Nipah virus disease.

    Science.gov (United States)

    Johnston, Sara C; Briese, Thomas; Bell, Todd M; Pratt, William D; Shamblin, Joshua D; Esham, Heather L; Donnelly, Ginger C; Johnson, Joshua C; Hensley, Lisa E; Lipkin, W Ian; Honko, Anna N

    2015-01-01

    Henipaviruses are implicated in severe and frequently fatal pneumonia and encephalitis in humans. There are no approved vaccines or treatments available for human use, and testing of candidates requires the use of well-characterized animal models that mimic human disease. We performed a comprehensive and statistically-powered evaluation of the African green monkey model to define parameters critical to disease progression and the extent to which they correlate with human disease. African green monkeys were inoculated by the intratracheal route with 2.5 × 10(4) plaque forming units of the Malaysia strain of Nipah virus. Physiological data captured using telemetry implants and assessed in conjunction with clinical pathology were consistent with shock, and histopathology confirmed widespread tissue involvement associated with systemic vasculitis in animals that succumbed to acute disease. In addition, relapse encephalitis was identified in 100% of animals that survived beyond the acute disease phase. Our data suggest that disease progression in the African green monkey is comparable to the variable outcome of Nipah virus infection in humans.

  14. Detailed analysis of the African green monkey model of Nipah virus disease.

    Directory of Open Access Journals (Sweden)

    Sara C Johnston

    Full Text Available Henipaviruses are implicated in severe and frequently fatal pneumonia and encephalitis in humans. There are no approved vaccines or treatments available for human use, and testing of candidates requires the use of well-characterized animal models that mimic human disease. We performed a comprehensive and statistically-powered evaluation of the African green monkey model to define parameters critical to disease progression and the extent to which they correlate with human disease. African green monkeys were inoculated by the intratracheal route with 2.5 × 10(4 plaque forming units of the Malaysia strain of Nipah virus. Physiological data captured using telemetry implants and assessed in conjunction with clinical pathology were consistent with shock, and histopathology confirmed widespread tissue involvement associated with systemic vasculitis in animals that succumbed to acute disease. In addition, relapse encephalitis was identified in 100% of animals that survived beyond the acute disease phase. Our data suggest that disease progression in the African green monkey is comparable to the variable outcome of Nipah virus infection in humans.

  15. African origins and chronic kidney disease susceptibility in the human immunodeficiency virus era.

    Science.gov (United States)

    Kasembeli, Alex N; Duarte, Raquel; Ramsay, Michèle; Naicker, Saraladevi

    2015-05-01

    Chronic kidney disease (CKD) is a major public health problem worldwide with the estimated incidence growing by approximately 6% annually. There are striking ethnic differences in the prevalence of CKD such that, in the United States, African Americans have the highest prevalence of CKD, four times the incidence of end stage renal disease when compared to Americans of European ancestry suggestive of genetic predisposition. Diabetes mellitus, hypertension and human immunodeficiency virus (HIV) infection are the major causes of CKD. HIV-associated nephropathy (HIVAN) is an irreversible form of CKD with considerable morbidity and mortality and is present predominantly in people of African ancestry. The APOL1 G1 and G2 alleles were more strongly associated with the risk for CKD than the previously examined MYH9 E1 risk haplotype in individuals of African ancestry. A strong association was reported in HIVAN, suggesting that 50% of African Americans with two APOL1 risk alleles, if untreated, would develop HIVAN. However these two variants are not enough to cause disease. The prevailing belief is that modifying factors or second hits (including genetic hits) underlie the pathogenesis of kidney disease. This work reviews the history of genetic susceptibility of CKD and outlines current theories regarding the role for APOL1 in CKD in the HIV era.

  16. Animal-adapted members of the Mycobacterium tuberculosis complex endemic to the southern African subregion

    Directory of Open Access Journals (Sweden)

    Charlene Clarke

    2016-02-01

    Full Text Available Members of the Mycobacterium tuberculosis complex (MTC cause tuberculosis (TB in both animals and humans. In this article, three animal-adapted MTC strains that are endemic to the southern African subregion – that is, Mycobacterium suricattae, Mycobacterium mungi, and the dassie bacillus – are reviewed with a focus on clinical and pathological presentations, geographic distribution, genotyping methods, diagnostic tools and evolution. Moreover, factors influencing the transmission and establishment of TB pathogens in novel host populations, including ecological, immunological and genetic factors of both the host and pathogen, are discussed. The risks associated with these infections are currently unknown and further studies will be required for greater understanding of this disease in the context of the southern African ecosystem.Keywords: dassie bacillus; ecology; evolution; host jump; Mycobacterium mungi; Mycobacterium suricattae; Mycobacterium tuberculosis complex; phylogeny

  17. Animal-adapted members of the Mycobacterium tuberculosis complex endemic to the southern African subregion.

    Science.gov (United States)

    Clarke, Charlene; Van Helden, Paul; Miller, Michele; Parsons, Sven

    2016-04-26

    Members of the Mycobacterium tuberculosis complex (MTC) cause tuberculosis (TB) in both animals and humans. In this article, three animal-adapted MTC strains that are endemic to the southern African subregion - that is, Mycobacterium suricattae, Mycobacterium mungi, and the dassie bacillus - are reviewed with a focus on clinical and pathological presentations, geographic distribution, genotyping methods, diagnostic tools and evolution. Moreover, factors influencing the transmission and establishment of TB pathogens in novel host populations, including ecological, immunological and genetic factors of both the host and pathogen, are discussed. The risks associated with these infections are currently unknown and further studies will be required for greater understanding of this disease in the context of the southern African ecosystem.

  18. Genome Analysis Linking Recent European and African Influenza (H5N1) Viruses

    Science.gov (United States)

    Kingsford, Carl; Cattoli, Giovanni; Spiro, David J.; Janies, Daniel A.; Aly, Mona Mehrez; Brown, Ian H.; Couacy-Hymann, Emmanuel; De Mia, Gian Mario; Dung, Do Huu; Guercio, Annalisa; Joannis, Tony; Ali, Ali Safar Maken; Osmani, Azizullah; Padalino, Iolanda; Saad, Magdi D.; Savić, Vladimir; Sengamalay, Naomi A.; Yingst, Samuel; Zaborsky, Jennifer; Zorman-Rojs, Olga; Ghedin, Elodie; Capua, Ilaria

    2007-01-01

    To better understand the ecology and epidemiology of the highly pathogenic avian influenza virus in its transcontinental spread, we sequenced and analyzed the complete genomes of 36 recent influenza A (H5N1) viruses collected from birds in Europe, northern Africa, and southeastern Asia. These sequences, among the first complete genomes of influenza (H5N1) viruses outside Asia, clearly depict the lineages now infecting wild and domestic birds in Europe and Africa and show the relationships among these isolates and other strains affecting both birds and humans. The isolates fall into 3 distinct lineages, 1 of which contains all known non-Asian isolates. This new Euro-African lineage, which was the cause of several recent (2006) fatal human infections in Egypt and Iraq, has been introduced at least 3 times into the European-African region and has split into 3 distinct, independently evolving sublineages. One isolate provides evidence that 2 of these sublineages have recently reassorted. PMID:17553249

  19. Current issues and considerations regarding trichomoniasis and human immunodeficiency virus in African-Americans.

    Science.gov (United States)

    Shafir, Shira C; Sorvillo, Frank J; Smith, Lisa

    2009-01-01

    Trichomonas vaginalis has long been recognized as one of the most prevalent sexually transmitted infections. However, it is only in recent years that it has been appreciated that Trichomonas may play a critical role in amplifying human immunodeficiency virus (HIV) transmission. Given the evidence that T. vaginalis likely promotes HIV infection, the apparent high level of Trichomonas infection in the African-American community is cause for concern. Even if T. vaginalis increases the risk of HIV transmission by a small or modest amount, it translates into a sizable population effect since Trichomonas is so common in this community. Therefore, control of trichomoniasis may represent an important avenue of control for the prevention of HIV transmission, particularly among African-Americans.

  20. Genomic analysis of highly virulent Georgia 2007/1 isolate of African swine fever virus.

    Science.gov (United States)

    Chapman, David A G; Darby, Alistair C; Da Silva, Melissa; Upton, Chris; Radford, Alan D; Dixon, Linda K

    2011-04-01

    African swine fever is widespread in Africa but has occasionally been introduced into other continents. In June 2007, African swine fever was isolated in the Caucasus Region of the Republic of Georgia and subsequently in neighboring countries (Armenia, Azerbaijan, and 9 states of the Russian Federation). Previous data for sequencing of 3 genes indicated that the Georgia 2007/1 isolate is closely related to isolates of genotype II, which has been identified in Mozambique, Madagascar, and Zambia. We report the complete genomic coding sequence of the Georgia 2007/1 isolate and comparison with other isolates. A genome sequence of 189,344 bp encoding 166 open reading frames (ORFs) was obtained. Phylogeny based on concatenated sequences of 125 conserved ORFs showed that this isolate clustered most closely with the Mkuzi 1979 isolate. Some ORFs clustered differently, suggesting that recombination may have occurred. Results provide a baseline for monitoring genomic changes in this virus.

  1. Inhibition of adaptive immune responses leads to a fatal clinical outcome in SIV-infected pigtailed macaques but not vervet African green monkeys.

    Directory of Open Access Journals (Sweden)

    Jörn E Schmitz

    2009-12-01

    Full Text Available African green monkeys (AGM and other natural hosts for simian immunodeficiency virus (SIV do not develop an AIDS-like disease following SIV infection. To evaluate differences in the role of SIV-specific adaptive immune responses between natural and nonnatural hosts, we used SIV(agmVer90 to infect vervet AGM and pigtailed macaques (PTM. This infection results in robust viral replication in both vervet AGM and pigtailed macaques (PTM but only induces AIDS in the latter species. We delayed the development of adaptive immune responses through combined administration of anti-CD8 and anti-CD20 lymphocyte-depleting antibodies during primary infection of PTM (n = 4 and AGM (n = 4, and compared these animals to historical controls infected with the same virus. Lymphocyte depletion resulted in a 1-log increase in primary viremia and a 4-log increase in post-acute viremia in PTM. Three of the four PTM had to be euthanized within 6 weeks of inoculation due to massive CMV reactivation and disease. In contrast, all four lymphocyte-depleted AGM remained healthy. The lymphocyte-depleted AGM showed only a trend toward a prolongation in peak viremia but the groups were indistinguishable during chronic infection. These data show that adaptive immune responses are critical for controlling disease progression in pathogenic SIV infection in PTM. However, the maintenance of a disease-free course of SIV infection in AGM likely depends on a number of mechanisms including non-adaptive immune mechanisms.

  2. Disinfection of foot-and-mouth disease and African swine fever viruses with citric acid and sodium hypochlorite on birch wood carriers

    Science.gov (United States)

    Transboundary animal disease viruses such as foot-and-mouth disease virus (FMDV) and African swine fever virus (ASFV) are highly contagious and cause severe morbidity and mortality in livestock. Proper disinfection during an outbreak can help prevent virus spread and will shorten the time for contam...

  3. Experimental Infection of Domestic Pigs with African Swine Fever Virus Lithuania 2014 Genotype II Field Isolate.

    Science.gov (United States)

    Gallardo, C; Soler, A; Nieto, R; Cano, C; Pelayo, V; Sánchez, M A; Pridotkas, G; Fernandez-Pinero, J; Briones, V; Arias, M

    2017-02-01

    An experimental infection was conducted to evaluate horizontal transmission, clinical, virological and humoral response induced in domestic pigs infected with African swine fever (ASF) genotype II virus circulating in 2014 into the European Union (EU). Ten naive pigs were placed in contact with eight pigs experimentally inoculated with the Lithuanian LT14/1490 ASF virus (ASFV) responsible for the first ASF case detected in wild boar in Lithuania in January 2014. Clinical examination and rectal temperature were recorded each day. Blood sampling from every animal was carried out twice weekly. Blood samples were examined for presence of ASF virus-specific antibodies and for determining the ASFV viral load. From the obtained results, it was concluded that the Lithuanian ASFV induced an acute disease which resulted in 94, 5% mortality. The disease was easily detected by real-time PCR prior to the onset of clinical signs and 33% of the animals seroconverted. All findings were in accordance with observations previously made in domestic pigs and wild boar when infected with ASF genotype II viruses characterized by a high virulence. One in-contact pig remained asymptomatic and survived the infection. The role of such animals in virus transmission would need further investigation.

  4. Rift Valley Fever Virus Circulating among Ruminants, Mosquitoes and Humans in the Central African Republic

    Science.gov (United States)

    Nakouné, Emmanuel; Kamgang, Basile; Berthet, Nicolas; Manirakiza, Alexandre; Kazanji, Mirdad

    2016-01-01

    Background Rift Valley fever virus (RVFV) causes a viral zoonosis, with discontinuous epizootics and sporadic epidemics, essentially in East Africa. Infection with this virus causes severe illness and abortion in sheep, goats, and cattle as well as other domestic animals. Humans can also be exposed through close contact with infectious tissues or by bites from infected mosquitoes, primarily of the Aedes and Culex genuses. Although the cycle of RVFV infection in savannah regions is well documented, its distribution in forest areas in central Africa has been poorly investigated. Methodology/Principal Findings To evaluate current circulation of RVFV among livestock and humans living in the Central African Republic (CAR), blood samples were collected from sheep, cattle, and goats and from people at risk, such as stock breeders and workers in slaughterhouses and livestock markets. The samples were tested for anti-RVFV immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies. We also sequenced the complete genomes of two local strains, one isolated in 1969 from mosquitoes and one isolated in 1985 from humans living in forested areas. The 1271 animals sampled comprised 727 cattle, 325 sheep, and 219 goats at three sites. The overall seroprevalence of anti-RVFV IgM antibodies was 1.9% and that of IgG antibodies was 8.6%. IgM antibodies were found only during the rainy season, but the frequency of IgG antibodies did not differ significantly by season. No evidence of recent RVFV infection was found in 335 people considered at risk; however, 16.7% had evidence of past infection. Comparison of the nucleotide sequences of the strains isolated in the CAR with those isolated in other African countries showed that they belonged to the East/Central African cluster. Conclusion and significance This study confirms current circulation of RVFV in CAR. Further studies are needed to determine the potential vectors involved and the virus reservoirs. PMID:27760144

  5. Protective immunization of horses with a recombinant canarypox virus vectored vaccine co-expressing genes encoding the outer capsid proteins of African horse sickness virus.

    Science.gov (United States)

    Guthrie, Alan J; Quan, Melvyn; Lourens, Carina W; Audonnet, Jean-Christophe; Minke, Jules M; Yao, Jiansheng; He, Ling; Nordgren, Robert; Gardner, Ian A; Maclachlan, N James

    2009-07-16

    We describe the development and preliminary characterization of a recombinant canarypox virus vectored (ALVAC) vaccine for protective immunization of equids against African horse sickness virus (AHSV) infection. Horses (n=8) immunized with either of two concentrations of recombinant canarypox virus vector (ALVAC-AHSV) co-expressing synthetic genes encoding the outer capsid proteins (VP2 and VP5) of AHSV serotype 4 (AHSV-4) developed variable titres (horse immunized with a commercial recombinant canarypox virus vectored vaccine expressing the haemagglutinin genes of two equine influenza H3N8 viruses was seronegative to AHSV and following infection with virulent AHSV-4 developed pyrexia, thrombocytopenia and marked oedema of the supraorbital fossae typical of the "dikkop" or cardiac form of African horse sickness. AHSV was detected by virus isolation and quantitative reverse transcriptase polymerase chain reaction in the blood of the control horse from 8 days onwards after challenge infection whereas AHSV was not detected at any time in the blood of the ALVAC-AHSV vaccinated horses. The control horse seroconverted to AHSV by 2 weeks after challenge infection as determined by both virus neutralization and ELISA assays, whereas six of eight of the ALVAC-AHSV vaccinated horses did not seroconvert by either assay following challenge infection with virulent AHSV-4. These data confirm that the ALVAC-AHSV vaccine will be useful for the protective immunization of equids against African horse sickness, and avoids many of the problems inherent to live-attenuated AHSV vaccines.

  6. An African horse sickness virus serotype 4 recombinant canarypox virus vaccine elicits specific cell-mediated immune responses in horses.

    Science.gov (United States)

    El Garch, H; Crafford, J E; Amouyal, P; Durand, P Y; Edlund Toulemonde, C; Lemaitre, L; Cozette, V; Guthrie, A; Minke, J M

    2012-09-15

    A recombinant canarypox virus vectored vaccine co-expressing synthetic genes encoding outer capsid proteins, VP2 and VP5, of African horse sickness virus (AHSV) serotype 4 (ALVAC(®)-AHSV4) has been demonstrated to fully protect horses against homologous challenge with virulent field virus. Guthrie et al. (2009) detected weak and variable titres of neutralizing antibody (ranging from horses received two vaccinations twenty-eight days apart and three horses remained unvaccinated. The detection of VP2/VP5 specific IFN-γ responses was assessed by enzyme linked immune spot (ELISpot) assay and clearly demonstrated that all ALVAC(®)-AHSV4 vaccinated horses developed significant IFN-γ production compared to unvaccinated horses. More detailed immune responses obtained by flow cytometry demonstrated that ALVAC(®)-AHSV4 vaccinations induced immune cells, mainly CD8(+) T cells, able to recognize multiple T-epitopes through all VP2 and only the N-terminus sequence of VP5. Neither VP2 nor VP5 specific IFN-γ responses were detected in unvaccinated horses. Overall, our data demonstrated that an experimental recombinant canarypox based vaccine induced significant CMI specific for both VP2 and VP5 proteins of AHSV4.

  7. BacMam immunization partially protects pigs against sublethal challenge with African swine fever virus.

    Science.gov (United States)

    Argilaguet, Jordi M; Pérez-Martín, Eva; López, Sergio; Goethe, Martin; Escribano, J M; Giesow, Katrin; Keil, Günther M; Rodríguez, Fernando

    2013-04-01

    Lack of vaccines and efficient control measures complicate the control and eradication of African swine fever (ASF). Limitations of conventional inactivated and attenuated virus-based vaccines against African swine fever virus (ASFV) highlight the need to use new technologies to develop efficient and safe vaccines against this virus. With this aim in mind, in this study we have constructed BacMam-sHAPQ, a baculovirus based vector for gene transfer into mammalian cells, expressing a fusion protein comprising three in tandem ASFV antigens: p54, p30 and the extracellular domain of the viral hemagglutinin (secretory hemagglutinin, sHA), under the control of the human cytomegalovirus immediate early promoter (CMVie). Confirming its correct in vitro expression, BacMam-sHAPQ induced specific T-cell responses directly after in vivo immunization. Conversely, no specific antibody responses were detectable prior to ASFV challenge. The protective potential of this recombinant vaccine candidate was tested by a homologous sublethal challenge with ASFV following immunization. Four out of six immunized pigs remained viremia-free after ASFV infection, while the other two pigs showed similar viremic titres to control animals. The protection afforded correlated with the presence of a large number of virus-specific IFNγ-secreting T-cells in blood at 17 days post-infection. In contrast, the specific antibody levels observed after ASFV challenge in sera from BacMam-sHAPQ immunized pigs were indistinguishable from those found in control pigs. These results highlight the importance of the cellular responses in protection against ASFV and point towards BacMam vectors as potential tools for future vaccine development.

  8. Seroprevalence of Zika Virus in Wild African Green Monkeys and Baboons

    Science.gov (United States)

    Buechler, Connor R.; Bailey, Adam L.; Weiler, Andrea M.; Barry, Gabrielle L.; Breitbach, Meghan E.; Stewart, Laurel M.; Jasinska, Anna J.; Freimer, Nelson B.; Apetrei, Cristian; Phillips-Conroy, Jane E.; Jolly, Clifford J.; Rogers, Jeffrey; Friedrich, Thomas C.

    2017-01-01

    ABSTRACT Zika virus (ZIKV) has recently spread through the Americas and has been associated with a range of health effects, including birth defects in children born to women infected during pregnancy. Although the natural reservoir of ZIKV remains poorly defined, the virus was first identified in a captive “sentinel” macaque monkey in Africa in 1947. However, the virus has not been reported in humans or nonhuman primates (NHPs) in Africa outside Gabon in over a decade. Here, we examine ZIKV infection in 239 wild baboons and African green monkeys from South Africa, the Gambia, Tanzania, and Zambia using combinations of unbiased deep sequencing, quantitative reverse transcription-PCR (qRT-PCR), and an antibody capture assay that we optimized using serum collected from captive macaque monkeys exposed to ZIKV, dengue virus, and yellow fever virus. While we did not find evidence of active ZIKV infection in wild NHPs in Africa, we found variable ZIKV seropositivity of up to 16% in some of the NHP populations sampled. We anticipate that these results and the methodology described within will help in continued efforts to determine the prevalence, natural reservoir, and transmission dynamics of ZIKV in Africa and elsewhere. IMPORTANCE Zika virus (ZIKV) is a mosquito-borne virus originally discovered in a captive monkey living in the Zika Forest of Uganda, Africa, in 1947. Recently, an outbreak in South America has shown that ZIKV infection can cause myriad health effects, including birth defects in the children of women infected during pregnancy. Here, we sought to investigate ZIKV infection in wild African primates to better understand its emergence and spread, looking for evidence of active or prior infection. Our results suggest that up to 16% of some populations of nonhuman primate were, at some point, exposed to ZIKV. We anticipate that this study will be useful for future studies that examine the spread of infections from wild animals to humans in general and

  9. Outbreak of chikungunya due to virus of Central/East African genotype in Malaysia.

    Science.gov (United States)

    Noridah, O; Paranthaman, V; Nayar, S K; Masliza, M; Ranjit, K; Norizah, I; Chem, Y K; Mustafa, B; Kumarasamy, V; Chua, K B

    2007-10-01

    Chikungunya is an acute febrile illness caused by an alphavirus which is transmitted by infective Aedes mosquitoes. Two previous outbreaks of chikungunya in Malaysia were due to chikungunya virus of Asian genotype. The present outbreak involved two adjoining areas in the suburb of Ipoh city within the Kinta district of Perak, a state in the northern part of Peninsular Malaysia. Thirty seven residents in the main outbreak area and two patients in the secondary area were laboratory confirmed to be infected with the virus. The index case was a 44-year Indian man who visited Paramakudi, Tamil Naidu, India on 21st November 2006 and returned home on 30th of November 2006, and subsequently developed high fever and joint pain on the 3rd of December 2006. A number of chikungunya virus isolates were isolated from both patients and Aedes albopictus mosquitoes in the affected areas. Molecular study showed that the chikungunya virus causing the Kinta outbreak was of the Central/East African genotype which occurred for the first time in Malaysia.

  10. Validation of ELISA for the detection of African horse sickness virus antigens and antibodies.

    Science.gov (United States)

    Rubio, C; Cubillo, M A; Hooghuis, H; Sanchez-Vizcaino, J M; Diaz-Laviada, M; Plateau, E; Zientara, S; Crucière, C; Hamblin, C

    1998-01-01

    The mortality rate in susceptible populations of horses during an epizootic of African horse sickness (AHS) may be in excess of 90%. Rapid and reliable assays are therefore essential for the confirmation of clinical diagnoses and to enable control strategies to be implemented without undue delay. One of the major objectives of a recent European Union funded project was the validation of newly developed diagnostic assays which are rapid, sensitive, highly reproducible and inexpensive, for the detection of African horse sickness virus (AHSV) antigens and antibodies. The Laboratorio de Sanidad y Produccion Animal (LSPA) in Algete, Spain was charged with the responsibility of co-ordinating and supplying samples of viruses and antisera to the participating laboratories in Spain, France and the United Kingdom. The panels comprised 76 antigen samples for assay by indirect sandwich ELISAs and 53 serum samples for antibody detection by either indirect or competitive ELISAs. Results generated by ELISA for each laboratory were analysed in LSPA in terms of their relative sensitivities and specificities. There was a good agreement between the ELISAs used for either antigen or antibody detection. The participating groups agreed that any field sample giving a doubtful result would always be retested by ELISA and an alternative assay.

  11. Diagnosis and genotyping of African swine fever viruses from 2015 outbreaks in Zambia

    Directory of Open Access Journals (Sweden)

    Jonas Thoromo

    2016-03-01

    Full Text Available In early 2015, a highly fatal haemorrhagic disease of domestic pigs resembling African swine fever (ASF occurred in North Western, Copperbelt, and Lusaka provinces of Zambia. Molecular diagnosis by polymerase chain reaction targeting specific amplification of p72 (B646L gene of ASF virus (ASFV was conducted. Fourteen out of 16 domestic pigs from the affected provinces were found to be positive for ASFV. Phylogenetic analyses based on part of the p72 and the complete p54 (E183L genes revealed that all the ASFVs detected belonged to genotypes I and Id, respectively. Additionally, epidemiological data suggest that the same ASFV spread from Lusaka to other provinces possibly through uncontrolled and/or illegal pig movements. Although the origin of the ASFV that caused outbreaks in domestic pigs in Zambia could not be ascertained, it appears likely that the virus may have emerged from within the country or region, probably from a sylvatic cycle. It is recommended that surveillance of ASF, strict biosecurity, and quarantine measures be imposed in order to prevent further spread and emergence of new ASF outbreaks in Zambia.Keywords: African swine fever; Asfarviridae; Molecular epidemiology; Zambia

  12. Propagation of human hepatitis A virus in African green monkey kidney cell culture: primary isolation and serial passage.

    OpenAIRE

    Daemer, R J; Feinstone, S M; Gust, I D; Purcell, R H

    1981-01-01

    Human hepatitis A virus (HAV) was propagated in primary African Green Monkey (Cercopithecus aethiops) kidney (AGMK) cell cultures. Three strains of HAV were used: MS-1, SD-11, and HM-175. Cells were inoculated with marmoset-passaged material or human clinical specimens and were stained by direct immunofluorescence to establish the identity of the virus. Both clinical samples and marmoset-passaged material produced immunofluorescence. HAV antigen was found scattered throughout the cytoplasm of...

  13. Characterisation of recent foot-and-mouth disease viruses from African buffalo ( Syncerus caffer )and cattle in Kenya is consistent with independent virus populations

    DEFF Research Database (Denmark)

    Nabalayo Wekesa, Sabenzia; Kiprotich Sangula, Abraham; Belsham, Graham;

    2015-01-01

    Background Understanding the epidemiology of foot-and-mouth disease (FMD), including roles played by different hosts, is essential for improving disease control. The African buffalo (Syncerus caffer) is a reservoir for the SAT serotypes of FMD virus (FMDV). Large buffalo populations commonly...

  14. Towards adaptive fire management for biodiversity conservation: Experience in South African National Parks

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    Brian W. van Wilgen

    2011-05-01

    Full Text Available This paper reviews the experience gained in three South African national parks (Kruger, Table Mountain and Bontebok with regard to the adaptive management of fire for the conservation of biodiversity. In the Kruger National Park, adaptive approaches have evolved over the past 15 years, beginning initially as a form of ‘informed trial and error’, but progressing towards active adaptive management in which landscape-scale, experimental burning treatments are being applied in order to learn. In the process, significant advances in understanding regarding the role and management of fire have been made. Attempts have been made to transfer the approaches developed in Kruger National Park to the other two national parks. However, little progress has been made to date, both because of a failure to provide an agreed context for the introduction of adaptive approaches, and because (in the case of Bontebok National Park too little time has passed to be able to make an assessment. Fire management interventions, ultimately, will manifest themselves in terms of biodiversity outcomes, but definite links between fire interventions and biodiversity outcomes have yet to be made.Conservation implications: Significant challenges face the managers of fire-prone and fire adapted ecosystems, where the attainment of ecosystem goals may require approaches (like encouraging high-intensity fires at hot and dry times of the year that threaten societal goals related to safety. In addition, approaches to fire management have focused on encouraging particular fire patterns in the absence of a sound understanding of their ecological outcomes. Adaptive management offers a framework for addressing these issues, but will require higher levels of agreement, monitoring and assessment than have been the case to date.

  15. Complete Genome Sequences of Two Chikungunya Viruses Isolated in the Central African Republic in the 1970s and 1980s

    Science.gov (United States)

    Desdouits, Marion; Nakouné, Emmanuel; Gessain, Antoine; Kazanji, Mirdad; Berthet, Nicolas

    2017-01-01

    ABSTRACT Some arboviruses threaten human global health with potentially explosive emergence. Analysis of whole-genome sequences of decades-old isolates might contribute to the understanding of the complex dynamics which drive their circulation and emergence. Here, we report the whole-genome sequences of two Chikungunya viruses isolated in the Central African Republic in the 1970s and 1980s. PMID:28254965

  16. In situ hybridization with labeled probes: assessment of african Swine Fever virus in formalin-fixed paraffin-embedded tissues.

    Science.gov (United States)

    Ballester, Maria; Rodríguez, Fernando

    2015-01-01

    In situ hybridization (ISH) has become a very valuable molecular diagnostic tool to detect specific DNA or RNA sequences in biological samples through the use of complementary DNA- or RNA-labeled probes. Here, we describe an optimized in situ hybridization protocol to detect African swine fever virus (ASFV) DNA in formalin-fixed, paraffin-embedded tissues using digoxigenin-labeled probes.

  17. Deletion of the thymidine kinase gene induces complete attenuation of the Georgia isolate of African swine fever virus

    Science.gov (United States)

    African swine fever virus (ASFV) is the etiological agent of a contagious and often lethal viral disease of domestic pigs. There are no vaccines to control Africa swine fever (ASF). Experimental vaccines have been developed using genetically modified live attenuated ASFVs obtained by specifically de...

  18. Sensitive detection of African swine fever virus using real-time PCR with a 5' conjugated minor groove binding probe

    DEFF Research Database (Denmark)

    McKillan, John; McMenamy, Michael; Hjertner, Bernt;

    2010-01-01

    The design of a 5′ conjugated minor groove binder (MGB) probe real-time PCR assay is described for the rapid, sensitive and specific detection of African swine fever virus (ASFV) DNA. The assay is designed against the 9GL region and is capable of detecting 20 copies of a DNA standard. It does...

  19. Transcriptional immunoresponse of tissue-specific macrophages in swine after infection with African swine fever virus

    Directory of Open Access Journals (Sweden)

    Kowalczyk Andrzej

    2015-12-01

    Full Text Available Macrophages and cytokines are important in the control of inflammation and regulation of the immune response. However, they can also contribute to immunopathology in the host after viral infection and the regulatory network can be subverted by infectious agents, including viruses, some of which produce cytokine analogues or have mechanisms that inhibit cytokine function. African swine fever virus (ASFV encodes a number of proteins which modulate cytokine and chemokine induction, host transcription factor activation, stress responses, and apoptosis. The aim of this review is to elucidate the mechanisms of immune responses to ASFV in different subpopulations of porcine macrophages. A transcriptional immune response in different resident tissue macrophages following ASFV infection was presented in many publications. ASFV-susceptible porcine macrophages can be of several origins, such as peripheral blood, lungs, bone marrow, etc. blood monocytes, blood macrophages, and lung macrophages have demonstrated a modulation of phenotype. Monocyte-derived macrophages could express surface markers not found on their monocyte precursors. Moreover, they can undergo further differentiation after infection and during inflammation. When viruses infect such cells, immunological activity can be seriously impaired or modified.

  20. The spread and maturation of strategic adaptive management within and beyond South African national parks

    Directory of Open Access Journals (Sweden)

    Stefanie Freitag

    2014-09-01

    Full Text Available Natural resource management is embedded within social-ecological environments and requires decisions to be taken within this broad context, including those that pertain to protected areas. This realization has led to South African National Parks adopting a strategic adaptive management approach to decision making. Through narrative, we show why and how this practice has progressively spread and evolved both within the organization and beyond, over the past two decades. A number of catalytic events and synergies enabled a change from reactive tactical management approaches to more inclusive forward-looking approaches able to embrace system complexity and associated uncertainty and change. We show how this long period of innovation has lead to an increased appreciation for the heterogeneous social-ecological system, and for the importance of constructing relationships and colearning, such that organizational transformation has enabled more legitimate and effective operation within an expanding and diversifying constituency.

  1. Adaptation of a Cancer Clinical Trials Education Program for African American and Latina/o Community Members

    Science.gov (United States)

    Pelto, Debra J.; Sadler, Georgia Robins; Njoku, Ogo; Rodriguez, Maria Carina; Villagra, Cristina; Malcarne, Vanessa L.; Riley, Natasha E.; Behar, Alma I.; Jandorf, Lina

    2016-01-01

    The pilot study reported in this article culturally and linguistically adapted an educational intervention to promote cancer clinical trials (CCTs) participation among Latinas/os and African Americans. The single-session slide presentation with embedded videos, originally developed through a campus-community partnership in Southern California, was…

  2. A culturally adapted depression intervention for African American adults experiencing depression: Oh Happy Day.

    Science.gov (United States)

    Ward, Earlise C; Brown, Roger L

    2015-01-01

    The purpose of this article is to describe development of a culturally adapted depression intervention (Oh Happy Day Class, OHDC) designed for African American adults experiencing major depressive disorder (MDD). This project included 2 pilot studies testing the feasibility and acceptability of the OHDC and examining short-term effects of the OHDC in reducing symptoms of MDD. The OHDC is a 2.5-hr weekly, culturally specific, cognitive behavioral, group counseling intervention for 12 weeks. Cultural adaptations of the OHDC are based on the ecological validity and culturally sensitive framework, along with an Afrocentric paradigm. Fifty African American participants with MDD were enrolled (15 in Pilot I and 35 in Pilot II). All participants in Pilots I and II received the 12-week intervention and completed assessments at baseline, mid-intervention, end-intervention, and 3 months postintervention. General linear mixed modeling for assessment of pre-post longitudinal data analysis was conducted. Results for Pilot I showed 73% of participants completed the full OHDC, a statistically significant decline in depression symptoms from pre- to postintervention, and a 0.38 effect size. Participants were very satisfied with the OHDC. In Pilot II, 66% of participants completed the full OHDC, and there was a significant pre-post intervention decrease in depression symptoms. For men, the OHDC showed a 1.01 effect size and for women, a 0.41 effect size. Both men and women were very satisfied with the OHDC based on the satisfaction measure. These promising findings are discussed with a focus on future plans for examining efficacy of the OHDC in a large-scale, randomized, control trial.

  3. Phylogeographic analysis of African swine fever virus based on the p72 gene sequence.

    Science.gov (United States)

    Muangkram, Y; Sukmak, M; Wajjwalku, W

    2015-05-04

    African swine fever virus (ASFV) outbreak has been considered as an emerging and re-emerging disease for almost a century. Diagnostically, simple polymerase chain reaction and sequencing-based molecular detection could be employed for both viral identification and genotyping. This study established a novel phylogenetic analysis and epidemiology comparison based on 205 bp of p72 gene sequences. Based on this partial p72 fragment, an updated list of 44 different genotypes from a total of 516 ASFV sequences compiled from GenBank was generated. Nucleotide diversity was 0.04325 ± 0.00231. The analysis of spatial genetic variation divided the ASFV populations of the African continent into four clades (clade A: central and upper eastern Africa; clade B: eastern Africa; clade C: eastern and southern Africa; and clade D: southern Africa). These results and the developed protocol could serve as useful molecular tools for ASFV diagnosis from degraded DNA or putrefied samples, and also provide the phylogeographic perspective to identify the origin of viral outbreaks, facilitating the decision planning to limit their spread.

  4. JC polyoma virus interacts with APOL1 in African Americans with nondiabetic nephropathy.

    Science.gov (United States)

    Divers, Jasmin; Núñez, Marina; High, Kevin P; Murea, Mariana; Rocco, Michael V; Ma, Lijun; Bowden, Donald W; Hicks, Pamela J; Spainhour, Mitzie; Ornelles, David A; Kleiboeker, Steven B; Duncan, Kara; Langefeld, Carl D; Turner, Jolyn; Freedman, Barry I

    2013-12-01

    Individuals with HIV infection and two apolipoprotein L1 gene (APOL1) risk variants frequently develop nephropathy. Here we tested whether non-HIV viral infections influence nephropathy risk via interactions with APOL1 by assessing APOL1 genotypes and presence of urine JC and BK polyoma virus and plasma HHV6 and CMV by quantitative polymerase chain reaction. We analyzed 300 samples from unrelated and related first-degree relatives of African Americans with nondiabetic nephropathy using linear and nonlinear mixed models to account for familial relationships. The four groups evaluated were APOL1 zero/one versus two risk alleles, with or without nephropathy. Urine JCV and BKV were detected in 90 and 29 patients, respectively, whereas HHV6 and CMV were rare. Adjusting for family age at nephropathy, gender, and ancestry, presence of JCV genomic DNA in urine and APOL1 risk alleles were significantly negatively associated with elevated serum cystatin C, albuminuria (albumin-to-creatinine ratio over 30 mg/g), and kidney disease defined as an eGFR under 60 ml/min per 1.73 m(2) and/or albuminuria in an additive (APOL1 plus JCV) model. BK viruria was not associated with kidney disease. Thus, African Americans at increased risk for APOL1-associated nephropathy (two APOL1 risk variants) with JC viruria had a lower prevalence of kidney disease, suggesting that JCV interaction with APOL1 genotype may influence kidney disease risk.

  5. Pathology of porcine peripheral white blood cells during infection with African swine fever virus

    Directory of Open Access Journals (Sweden)

    Karalyan Zaven

    2012-02-01

    Full Text Available Abstract Background African swine fever virus (ASFV is the causative agent of African swine fever (ASF that is the significant disease of domestic pigs. Several studies showed that ASFV can influence on porcine blood cells in vitro. Thus, we asked ourselves whether ASFV infection results in changes in porcine blood cells in vivo. A series of experiments were performed in order to investigate the effects of ASFV infection on porcine peripheral white blood cells. Nine pigs were inoculated by intramuscular injection with 104 50% hemadsorbing doses of virus (genotype II distributed in Armenia and Georgia. The total number of fifteen cell types was calculated during experimental infection. Results Although band-to-segmented neutrophils ratio became much higher (3.5 in infected pigs than in control group (0.3, marked neutropenia and lymphopenia were detected from 2 to 3 days post-infection. In addition to band neutrophils, the high number of other immature white blood cells, such as metamyelocytes, was observed during the course of infection. From the beginning of infection, atypical lymphocytes, with altered nuclear shape, arose and became 15% of total cells in the final phase of infection. Image scanning cytometry revealed hyperdiploid DNA content in atypical lymphocytes only from 5 days post-infection, indicating that DNA synthesis in pathological lymphocytes occurred in the later stages of infection. Conclusion From this study, it can be concluded that ASFV infection leads to serious changes in composition of white blood cells. Particularly, acute ASFV infection in vivo is accompanied with the emergence of immature cells and atypical lymphocytes in the host blood. The mechanisms underlying atypical cell formation remain to be elucidated.

  6. Deletion of virulence associated genes from attenuated African swine fever virus isolate OUR T88/3 decreases its ability to protect against challenge with virulent virus.

    Science.gov (United States)

    Abrams, Charles C; Goatley, Lynnette; Fishbourne, Emma; Chapman, David; Cooke, Lyndsay; Oura, Christopher A; Netherton, Christopher L; Takamatsu, Haru-Hisa; Dixon, Linda K

    2013-08-15

    African swine fever virus (ASFV) causes an acute haemorrhagic disease of domestic pigs against which there is no effective vaccine. The attenuated ASFV strain OUR T88/3 has been shown previously to protect vaccinated pigs against challenge with some virulent strains including OUR T88/1. Two genes, DP71L and DP96R were deleted from the OUR T88/3 genome to create recombinant virus OUR T88/3ΔDP2. Deletion of these genes from virulent viruses has previously been shown to reduce ASFV virulence in domestic pigs. Groups of 6 pigs were immunised with deletion virus OUR T88/3ΔDP2 or parental virus OUR T88/3 and challenged with virulent OUR T88/1 virus. Four pigs (66%) were protected by inoculation with the deletion virus OUR T88/3ΔDP2 compared to 100% protection with the parental virus OUR T88/3. Thus the deletion of the two genes DP71L and DP96R from OUR T88/3 strain reduced its ability to protect pigs against challenge with virulent virus.

  7. The innate and adaptive immune response to avian influenza virus infections and vaccines

    Science.gov (United States)

    Protective immunity against viruses is mediated by the early innate immune responses and later on by the adaptive immune responses. The early innate immunity is designed to contain and limit virus replication in the host, primarily through cytokine and interferon production. Most all cells are cap...

  8. Immunization of African Indigenous Pigs with Attenuated Genotype I African Swine Fever Virus OURT88/3 Induces Protection Against Challenge with Virulent Strains of Genotype I.

    Science.gov (United States)

    Mulumba-Mfumu, L K; Goatley, L C; Saegerman, C; Takamatsu, H-H; Dixon, L K

    2016-10-01

    The attenuated African swine fever virus genotype I strain OURT88/3 has previously been shown to induce protection of European breeds of domestic pigs against challenge with virulent isolates. To determine whether protective immune responses could also be induced in indigenous breeds of pigs from the Kinshassa region in Democratic Republic of Congo, we immunized a group of eight pigs with OURT88/3 strain and challenged the pigs 3 weeks later with virulent genotype I strain OURT88/1. Four of the pigs were protected against challenge. Three of the eight pigs died from African swine fever virus and a fourth from an unknown cause. The remaining four pigs all survived challenge with a recent virulent genotype I strain from the Democratic Republic of Congo, DRC 085/10. Control groups of non-immune pigs challenged with OURT88/1 or DRC 085/10 developed signs of acute ASFV as expected and had high levels of virus genome in blood.

  9. Alterations of Nuclear Architecture and Epigenetic Signatures during African Swine Fever Virus Infection

    Directory of Open Access Journals (Sweden)

    Margarida Simões

    2015-09-01

    Full Text Available Viral interactions with host nucleus have been thoroughly studied, clarifying molecular mechanisms and providing new antiviral targets. Considering that African swine fever virus (ASFV intranuclear phase of infection is poorly understood, viral interplay with subnuclear domains and chromatin architecture were addressed. Nuclear speckles, Cajal bodies, and promyelocytic leukaemia nuclear bodies (PML-NBs were evaluated by immunofluorescence microscopy and Western blot. Further, efficient PML protein knockdown by shRNA lentiviral transduction was used to determine PML-NBs relevance during infection. Nuclear distribution of different histone H3 methylation marks at lysine’s 9, 27 and 36, heterochromatin protein 1 isoforms (HP1α, HPβ and HPγ and several histone deacetylases (HDACs were also evaluated to assess chromatin status of the host. Our results reveal morphological disruption of all studied subnuclear domains and severe reduction of viral progeny in PML-knockdown cells. ASFV promotes H3K9me3 and HP1β foci formation from early infection, followed by HP1α and HDAC2 nuclear enrichment, suggesting heterochromatinization of host genome. Finally, closeness between DNA damage response factors, disrupted PML-NBs, and virus-induced heterochromatic regions were identified. In sum, our results demonstrate that ASFV orchestrates spatio-temporal nuclear rearrangements, changing subnuclear domains, relocating Ataxia Telangiectasia Mutated Rad-3 related (ATR-related factors and promoting heterochromatinization, probably controlling transcription, repressing host gene expression, and favouring viral replication.

  10. Diagnosis and genotyping of African swine fever viruses from 2015 outbreaks in Zambia.

    Science.gov (United States)

    Thoromo, Jonas; Simulundu, Edgar; Chambaro, Herman M; Mataa, Liywalii; Lubaba, Caesar H; Pandey, Girja S; Takada, Ayato; Misinzo, Gerald; Mweene, Aaron S

    2016-04-29

    In early 2015, a highly fatal haemorrhagic disease of domestic pigs resembling African swine fever (ASF) occurred in North Western, Copperbelt, and Lusaka provinces of Zambia. Molecular diagnosis by polymerase chain reaction targeting specific amplification of p72 (B646L) gene of ASF virus (ASFV) was conducted. Fourteen out of 16 domestic pigs from the affected provinces were found to be positive for ASFV. Phylogenetic analyses based on part of the p72 and the complete p54 (E183L) genes revealed that all the ASFVs detected belonged to genotypes I and Id, respectively. Additionally, epidemiological data suggest that the same ASFV spread from Lusaka to other provinces possibly through uncontrolled and/or illegal pig movements. Although the origin of the ASFV that caused outbreaks in domestic pigs in Zambia could not be ascertained, it appears likely that the virus may have emerged from within the country or region, probably from a sylvatic cycle. It is recommended that surveillance of ASF, strict biosecurity, and quarantine measures be imposed in order to prevent further spread and emergence of new ASF outbreaks in Zambia.

  11. African swine fever virus ORF P1192R codes for a functional type II DNA topoisomerase.

    Science.gov (United States)

    Coelho, João; Martins, Carlos; Ferreira, Fernando; Leitão, Alexandre

    2015-01-01

    Topoisomerases modulate the topological state of DNA during processes, such as replication and transcription, that cause overwinding and/or underwinding of the DNA. African swine fever virus (ASFV) is a nucleo-cytoplasmic double-stranded DNA virus shown to contain an OFR (P1192R) with homology to type II topoisomerases. Here we observed that pP1192R is highly conserved among ASFV isolates but dissimilar from other viral, prokaryotic or eukaryotic type II topoisomerases. In both ASFV/Ba71V-infected Vero cells and ASFV/L60-infected pig macrophages we detected pP1192R at intermediate and late phases of infection, cytoplasmically localized and accumulating in the viral factories. Finally, we used a Saccharomyces cerevisiae temperature-sensitive strain in order to demonstrate, through complementation and in vitro decatenation assays, the functionality of P1192R, which we further confirmed by mutating its predicted catalytic residue. Overall, this work strengthens the idea that P1192R constitutes a target for studying, and possibly controlling, ASFV transcription and replication.

  12. [On the situation of African swine fever and the biological characterization of recent virus isolates].

    Science.gov (United States)

    Tauscher, Kerstin; Pietschmann, Jana; Wernike, Kerstin; Teifke, Jens P; Beer, Martin; Blome, Sandra

    2015-01-01

    African swine fever (ASF), a disease notifiable to the World Organization of Animal Health (OIE), is characterized by severe, unspecific clinical signs and high mortality rates. Hosts for ASF virus (ASFV) are only members of the family Suidae and soft ticks of the genus Ornithodoros. Currently, no vaccine is available and therefore, the control is primarily based on strict sanitary measures. The most important part is the early detection of the disease within affected animal holdings and the fast and reliable confirmation by laboratory diagnosis. Infections of domestic pigs and European wild boar with recent Armenian, Sardinian, Lithuanian or Kenyan ASFV isolates lead to severe, acute disease courses with the predominant symptom of high fever (> 41 degrees C) accompanied by further unspecific clinical signs such as lethargy, loss of appetite, diarrhoea, respiratory symptoms, and an increased bleeding tendency. In experimental infection studies the mortality rate reached 100%. The most prominent pathomorphological findings included ebony-colored gastrohepatic lymph nodes, lung oedema, petechiae in the renal cortex, and oedema of the gallbladder wall. In the light of the current epidemiological situation with endemic ASFV infections on Sardinia, outbreaks in Russia and several Eastern EU Member States there is a risk for an introduction in further, previously unaffected EU countries including Germany. Hence, appropriate sample materials (serum, blood, spleen) of domestic pigs with unspecific clinical symptoms or pathomorphological findings should be examined for both ASFV and classical swine fever virus.

  13. Correlation of cell surface marker expression with African swine fever virus infection.

    Science.gov (United States)

    Lithgow, Pamela; Takamatsu, Haru; Werling, Dirk; Dixon, Linda; Chapman, Dave

    2014-01-31

    The expression of surface markers on African swine fever virus (ASFV) infected cells was evaluated to assess their involvement in infection. Previous findings indicated CD163 expression was correlated with ASFV susceptibility. However, in this study the expression of porcine CD163 on cell lines did not increase the infection rate of these cells indicating other factors are likely to be important in determining susceptibility to infection. On adherent porcine bone marrow (pBM) cells the expression of CD45 was strongly correlated with infection. CD163 and CD203a expression correlated at intermediate levels with infection, indicating cells expressing these markers could become infected but were not preferentially infected by the virus. Most of the cells expressing MHCII were infected, indicating that they may be preferentially infected although expression of MHCII was not essential for infection and a large percentage of the infected cells were MHCII negative. CD16 showed a marked decrease in expression following infection and significantly lower levels of infected cells were shown to express CD16. Altogether these results suggest CD163 may be involved in ASFV infection but it may not be essential; the results also highlight the importance of other cell markers which requiring further investigation.

  14. Transmission routes of African swine fever virus to domestic pigs: current knowledge and future research directions.

    Science.gov (United States)

    Guinat, Claire; Gogin, Andrey; Blome, Sandra; Keil, Guenther; Pollin, Reiko; Pfeiffer, Dirk U; Dixon, Linda

    2016-03-12

    African swine fever (ASF) is a major threat to the pig industry in Europe. Since 2007, ASF outbreaks have been ongoing in the Caucasus, Eastern Europe and the Baltic countries, causing severe economic losses for many pig farmers and pork producers. In addition, the number of ASF cases in wild boar populations has dramatically increased over the past few years. Evidence supports direct contact with infectious domestic pigs and wild boars, and consumption of contaminated feed, as the main transmission routes of ASF virus (ASFV) to domestic pigs. However, significant knowledge gaps highlight the urgent need for research to investigate the dynamics of indirect transmission via the environment, the minimal infective doses for contaminated feed ingestion, the probability of effective contacts between infectious wild boars and domestic pigs, the potential for recovered animals to become carriers and a reservoir for transmission, the potential virus persistence within wild boar populations and the influence of human behaviour for the spread of ASFV. This will provide an improved scientific basis to optimise current interventions and develop new tools and strategies to reduce the risk of ASFV transmission to domestic pigs.

  15. Dynamin- and Clathrin-Dependent Endocytosis in African Swine Fever Virus Entry▿

    Science.gov (United States)

    Hernaez, Bruno; Alonso, Covadonga

    2010-01-01

    African swine fever virus (ASFV) is a large DNA virus that enters host cells after receptor-mediated endocytosis and depends on acidic cellular compartments for productive infection. The exact cellular mechanism, however, is largely unknown. In order to dissect ASFV entry, we have analyzed the major endocytic routes using specific inhibitors and dominant negative mutants and analyzed the consequences for ASFV entry into host cells. Our results indicate that ASFV entry into host cells takes place by clathrin-mediated endocytosis which requires dynamin GTPase activity. Also, the clathrin-coated pit component Eps15 was identified as a relevant cellular factor during infection. The presence of cholesterol in cellular membranes, but not lipid rafts or caveolae, was found to be essential for a productive ASFV infection. In contrast, inhibitors of the Na+/H+ ion channels and actin polymerization inhibition did not significantly modify ASFV infection, suggesting that macropinocytosis does not represent the main entry route for ASFV. These results suggest a dynamin-dependent and clathrin-mediated endocytic pathway of ASFV entry for the cell types and viral strains analyzed. PMID:19939916

  16. Sequence adaptations during growth of rescued classical swine fever viruses in cell culture and within infected pigs

    DEFF Research Database (Denmark)

    Hadsbjerg, Johanne; Friis, Martin Barfred; Fahnøe, Ulrik

    2016-01-01

    RNA could be detected. However, the animals inoculated with these mutant viruses seroconverted against CSFV. Thus, these mutant viruses were highly attenuated in vivo. All 4 rescued viruses were also passaged up to 20 times in cell culture. Using full genome sequencing, the same two adaptations within...... adaptation and to identify key determinants of viral replication efficiency in cells and within host animals....

  17. Endosomal maturation, Rab7 GTPase and phosphoinositides in African swine fever virus entry.

    Directory of Open Access Journals (Sweden)

    Miguel A Cuesta-Geijo

    Full Text Available Here we analyzed the dependence of African swine fever virus (ASFV infection on the integrity of the endosomal pathway. Using confocal immunofluorescence with antibodies against viral capsid proteins, we found colocalization of incoming viral particles with early endosomes (EE during the first minutes of infection. Conversely, viral capsid protein was not detected in acidic late endosomal compartments, multivesicular bodies (MVBs, late endosomes (LEs or lysosomes (LY. Using an antibody against a viral inner core protein, we found colocalization of viral cores with late compartments from 30 to 60 minutes postinfection. The absence of capsid protein staining in LEs and LYs suggested that virus desencapsidation would take place at the acid pH of these organelles. In fact, inhibitors of intraluminal acidification of endosomes caused retention of viral capsid staining virions in Rab7 expressing endosomes and more importantly, severely impaired subsequent viral protein production. Endosomal acidification in the first hour after virus entry was essential for successful infection but not thereafter. In addition, altering the balance of phosphoinositides (PIs which are responsible of the maintenance of the endocytic pathway impaired ASFV infection. Early infection steps were dependent on the production of phosphatidylinositol 3-phosphate (PtdIns3P which is involved in EE maturation and multivesicular body (MVB biogenesis and on the interconversion of PtdIns3P to phosphatidylinositol 3, 5-biphosphate (PtdIns(3,5P(2. Likewise, GTPase Rab7 activity should remain intact, as well as processes related to LE compartment physiology, which are crucial during early infection. Our data demonstrate that the EE and LE compartments and the integrity of the endosomal maturation pathway orchestrated by Rab proteins and PIs play a central role during early stages of ASFV infection.

  18. Cultural Adaptations of Prolonged Exposure Therapy for Treatment and Prevention of Posttraumatic Stress Disorder in African Americans

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    Monnica T. Williams

    2014-05-01

    Full Text Available Posttraumatic stress disorder (PTSD is a highly disabling disorder, afflicting African Americans at disproportionately higher rates than the general population. When receiving treatment, African Americans may feel differently towards a European American clinician due to cultural mistrust. Furthermore, racism and discrimination experienced before or during the traumatic event may compound posttrauma reactions, impacting the severity of symptoms. Failure to adapt treatment approaches to encompass cultural differences and racism-related traumas may decrease treatment success for African American clients. Cognitive behavioral treatment approaches are highly effective, and Prolonged Exposure (PE in particular has the most empirical support for the treatment of PTSD. This article discusses culturally-informed adaptations of PE that incorporates race-related trauma themes specific to the Black experience. These include adding more sessions at the front end to better establish rapport, asking directly about race-related themes during the assessment process, and deliberately bringing to the forefront race-related experiences and discrimination during treatment when indicated. Guidelines for assessment and the development of appropriate exposures are provided. Case examples are presented demonstrating adaptation of PE for a survivor of race-related trauma and for a woman who developed internalized racism following a sexual assault. Both individuals experienced improvement in their posttrauma reactions using culturally-informed adaptations to PE.

  19. Adaptive evolution of simian immunodeficiency viruses isolated from two conventional progressor macaques with neuroaids

    Energy Technology Data Exchange (ETDEWEB)

    Foley, Brian T [Los Alamos National Laboratory; Korber, Bette T [Los Alamos National Laboratory

    2008-01-01

    Simian immunodeficiency virus infection of macaques may result in neuroAIDS, a feature more commonly observed in macaques with rapid progressive disease than in those with conventional disease. This is the first report of two conventional progressors (H631 and H636) with encephalitis in rhesus macaques inoculated with a derivative of SIVsmES43-3. Phylogenetic analyses of viruses isolated from the cerebral spinal fluid (CSF) and plasma from both animals demonstrated tissue compartmentalization. Additionally, virus from the central nervous system (CNS) was able to infect primary macaque monocyte-derived macrophages more efficiently than virus from plasma. Conversely, virus isolated from plasma was able to replicate better in peripheral blood mononuclear cells than virus from CNS. We speculate that these viruses were under different selective pressures in their separate compartments. Furthermore, these viruses appear to have undergone adaptive evolution to preferentially replicate in their respective cell targets. Analysis of the number of potential N-linked glycosylation sites (PNGS) in gp160 showed that there was a statistically significant loss of PNGS in viruses isolated from CNS in both macaques compared to SIVsmE543-3. Moreover, virus isolated from the brain in H631, had statistically significant loss of PNGS compared to virus isolated from CSF and plasma of the same animal. It is possible that the brain isolate may have adapted to decrease the number of PNGS given that humoral immune selection pressure is less likely to be encountered in the brain. These viruses provide a relevant model to study the adaptations required for SIV to induce encephalitis.

  20. Newcastle disease virus in little owls (Athene noctua) and African penguins (Spheniscus demersus) in an Israeli zoo.

    Science.gov (United States)

    Haddas, R; Meir, R; Perk, S; Horowitz, I; Lapin, E; Rosenbluth, E; Lublin, A

    2014-12-01

    Newcastle disease is a contagious and often fatal disease, capable of affecting all species of birds. A velogenic Newcastle disease virus (vNDV) outbreak occurred in an Israeli zoo, in which Little owls (Athene noctua) and African penguins (Spheniscus demersus) were found positive for presence of NDV. Some of them have died. The diagnostic process included: post-mortem examination, histopathology, real-time RT-PCR assay, virus isolation, serology, intracerebral pathogenicity index and phylogenetic analysis. A vNDV was diagnosed and found to be closely related to isolates from vNDV outbreaks that occurred in commercial poultry flocks during 2011. All isolates were classified as lineage 5d.

  1. Effect of O. porcinus Tick Salivary Gland Extract on the African Swine Fever Virus Infection in Domestic Pig.

    Directory of Open Access Journals (Sweden)

    Jennifer Bernard

    Full Text Available African swine fever is a haemorrhagic disease in pig production that can have disastrous financial consequences for farming. No vaccines are currently available and animal slaughtering or area zoning to restrict risk-related movements are the only effective measures to prevent the spread of the disease. Ornithodoros soft ticks are known to transmit the African swine fever virus (ASFV to pigs in farms, following the natural epidemiologic cycle of the virus. Tick saliva has been shown to modulate the host physiological and immunological responses during feeding on skin, thus affecting viral infection. To better understand the interaction between soft tick, ASFV and pig at the bite location and the possible influence of tick saliva on pig infection by ASFV, salivary gland extract (SGE of Ornithodoros porcinus, co-inoculated or not with ASFV, was used for intradermal auricular inoculation. Our results showed that, after the virus triggered the disease, pigs inoculated with virus and SGE presented greater hyperthermia than pigs inoculated with virus alone. The density of Langerhans cells was modulated at the tick bite or inoculation site, either through recruitment by ASFV or inhibition by SGE. Additionally, SGE and virus induced macrophage recruitment each. This effect was enhanced when they were co-inoculated. Finally, the co-inoculation of SGE and virus delayed the early local spread of virus to the first lymph node on the inoculation side. This study has shown that the effect of SGE was powerful enough to be quantified in pig both on the systemic and local immune response. We believe this model should be developed with infected tick and could improve knowledge of both tick vector competence and tick saliva immunomodulation.

  2. Effect of O. porcinus Tick Salivary Gland Extract on the African Swine Fever Virus Infection in Domestic Pig.

    Science.gov (United States)

    Bernard, Jennifer; Hutet, Evelyne; Paboeuf, Frédéric; Randriamparany, Tantely; Holzmuller, Philippe; Lancelot, Renaud; Rodrigues, Valérie; Vial, Laurence; Le Potier, Marie-Frédérique

    2016-01-01

    African swine fever is a haemorrhagic disease in pig production that can have disastrous financial consequences for farming. No vaccines are currently available and animal slaughtering or area zoning to restrict risk-related movements are the only effective measures to prevent the spread of the disease. Ornithodoros soft ticks are known to transmit the African swine fever virus (ASFV) to pigs in farms, following the natural epidemiologic cycle of the virus. Tick saliva has been shown to modulate the host physiological and immunological responses during feeding on skin, thus affecting viral infection. To better understand the interaction between soft tick, ASFV and pig at the bite location and the possible influence of tick saliva on pig infection by ASFV, salivary gland extract (SGE) of Ornithodoros porcinus, co-inoculated or not with ASFV, was used for intradermal auricular inoculation. Our results showed that, after the virus triggered the disease, pigs inoculated with virus and SGE presented greater hyperthermia than pigs inoculated with virus alone. The density of Langerhans cells was modulated at the tick bite or inoculation site, either through recruitment by ASFV or inhibition by SGE. Additionally, SGE and virus induced macrophage recruitment each. This effect was enhanced when they were co-inoculated. Finally, the co-inoculation of SGE and virus delayed the early local spread of virus to the first lymph node on the inoculation side. This study has shown that the effect of SGE was powerful enough to be quantified in pig both on the systemic and local immune response. We believe this model should be developed with infected tick and could improve knowledge of both tick vector competence and tick saliva immunomodulation.

  3. Effect of O. porcinus Tick Salivary Gland Extract on the African Swine Fever Virus Infection in Domestic Pig

    Science.gov (United States)

    Bernard, Jennifer; Hutet, Evelyne; Paboeuf, Frédéric; Randriamparany, Tantely; Holzmuller, Philippe; Lancelot, Renaud; Rodrigues, Valérie; Vial, Laurence; Le Potier, Marie-Frédérique

    2016-01-01

    African swine fever is a haemorrhagic disease in pig production that can have disastrous financial consequences for farming. No vaccines are currently available and animal slaughtering or area zoning to restrict risk-related movements are the only effective measures to prevent the spread of the disease. Ornithodoros soft ticks are known to transmit the African swine fever virus (ASFV) to pigs in farms, following the natural epidemiologic cycle of the virus. Tick saliva has been shown to modulate the host physiological and immunological responses during feeding on skin, thus affecting viral infection. To better understand the interaction between soft tick, ASFV and pig at the bite location and the possible influence of tick saliva on pig infection by ASFV, salivary gland extract (SGE) of Ornithodoros porcinus, co-inoculated or not with ASFV, was used for intradermal auricular inoculation. Our results showed that, after the virus triggered the disease, pigs inoculated with virus and SGE presented greater hyperthermia than pigs inoculated with virus alone. The density of Langerhans cells was modulated at the tick bite or inoculation site, either through recruitment by ASFV or inhibition by SGE. Additionally, SGE and virus induced macrophage recruitment each. This effect was enhanced when they were co-inoculated. Finally, the co-inoculation of SGE and virus delayed the early local spread of virus to the first lymph node on the inoculation side. This study has shown that the effect of SGE was powerful enough to be quantified in pig both on the systemic and local immune response. We believe this model should be developed with infected tick and could improve knowledge of both tick vector competence and tick saliva immunomodulation. PMID:26828597

  4. Evaluation of possible mitigation measures to prevent introduction and spread of African swine fever virus through wild boar

    Directory of Open Access Journals (Sweden)

    European Food Safety Authority

    2014-03-01

    Full Text Available This scientific report has been prepared in response to a request for urgent scientific and technical assistance under Art 31 of Regulation (EC No 178/2002, in relation to possible mitigation measures to prevent introduction and spread of African swine fever virus (ASFV. It was requested to assess the feasibility to drastically reduce the wild boar population by hunting or by the use of traps, and to assess if prevention of movement of wild boars by feeding or by artificial physical barriers reduces the risk of spread of ASFV. No evidence was found in scientific literature proving that wild boar populations can be drastically reduced by hunting or trapping in Europe. The main reasons are the adaptive behaviour of wild boar, compensatory growth of the population and the possible influx of wild boar from adjacent areas. Thus, drastic hunting is not a tool to reduce the risk for introduction and spread of ASFV in wild boar populations. Furthermore, wild boar density thresholds for introduction, spread and persistence of ASFV in the wild boar populations are currently impossible to establish, due to the uncertainty regarding the extent of the spread and maintenance of ASFV, the biases in population datasets, the complex population structures and dynamics. Furthermore, attempts to drastically reduce wild boar populations may even increase transmission and facilitate progressive geographical spread of ASFV, since intensive hunting pressure on wild boar populations leads to dispersion of groups and individuals. Artificial feeding of wild boar might increase the risk of ASFV spread. Fencing can restrict wild boar movements, however further knowledge of the ASF epidemiology and spatial distribution of wild boar is required to identify the areas where fencing could be used as one possible element of a control programme and to assess the feasibility of its implementation.

  5. First Detection of Antibodies Against African Swine Fever Virus in Faeces Samples.

    Science.gov (United States)

    Nieto-Pelegrín, E; Rivera-Arroyo, B; Sánchez-Vizcaíno, J M

    2015-12-01

    African swine fever (ASF) is a viral, highly lethal haemorrhagic disease of swine with no available vaccine or effective treatment. Introduction of ASF into a country triggers immediate restriction measures that cause significant economic losses and threatens spread to neighbouring countries. Wild boar populations have been recently assigned an essential role in the spread of African swine fever virus (ASFV) to European countries. Therefore, effective surveillance and monitoring of wild boar populations is required, but sampling wild boar is logistically challenging and expensive. This study assessed the feasibility of detecting antibodies against ASFV in faeces for later implementation in surveillance and control programmes. Two groups of pigs were experimentally infected with an attenuated ASFV isolate Ken05, and blood, oral fluid and faecal samples were tested for the presence of viral DNA using quantitative real-time polymerase chain reaction (qPCR) to monitor infection progress. Faecal samples were analysed using two indirect enzyme-linked immunosorbent assays (ELISAs) based on semipurified viral protein (vp) 72 or purified recombinant vp30 expressed in mammalian cells. Faecal samples from 9 of 10 pigs with non-haemorrhagic diarrhoea tested positive for antibodies against ASFV using the two ELISA tests that showed a positive correlation. The serum sample results from the two indirect ELISAs were compared against results from the reference ELISA technique and the immunoperoxidase test. Our findings indicate the feasibility of faecal sampling for detecting anti-ASFV antibodies, which may provide a practical non-invasive alternative for sampling wild boar populations. In conclusion, the application of these ELISA tests to faecal field samples could be particularly useful to screen for the presence of ASF in field conditions.

  6. Evaluation of hemostaseological status of pigs experimentally infected with African swine fever virus.

    Science.gov (United States)

    Zakaryan, Hovakim; Karalova, Elena; Voskanyan, Henrik; Ter-Pogossyan, Zarine; Nersisyan, Narek; Hakobyan, Astghik; Saroyan, David; Karalyan, Zaven

    2014-11-07

    African swine fever is a highly contagious hemorrhagic disease of pigs caused by African swine fever virus (ASFV). Hemorrhages are the most frequently reported lesions in acute and subacute forms of ASF. Hemorrhagic lesions are accompanied by impaired hemostasis, which includes thrombocytopenia and changes in the coagulation system. In the present study, experimental infection was conducted to elucidate whether a highly virulent ASFV genotype II circulating in the Trans-Caucasus and Eastern Europe affects the hemostasis of infected pigs. Platelet count changes and platelet size, as well as coagulation parameters were evaluated upon experimental infection. In contrast to other ASFV strains, ASFV genotype II showed a significant decrease in the number of platelets from 3rd dpi onwards. Furthermore, a decrease in platelet size was observed throughout the entire period of experiment. A significant increase in the number of platelet aggregates was observed from the beginning of infection. Unlike other ASFV strains, ASFV genotype II induced a slight shortening of an activated partial thromboplastin time (aPTT) throughout the experiment. Thrombin time (TT) was prolonged from day 5 onwards, whereas no changes in prothrombin time (PT) were found upon infection. The level of d-dimers was permanently higher than in control with a peak on day 3 post-infection. ASFV induced a significant decrease in the level of fibrinogen from day 5 till the end of experiment. Thus, it can be concluded that ASFV genotype II isolated in Armenia affects the hemostasis of infected pigs and causes changes that differ from that of other ASFV strains described previously.

  7. Deletion of African swine fever virus Georgia 2007 virulence-associated gene 9GL (B119L) leads to virus attenuation in swine at low doses while inducing an effective protection against homologous challenge

    Science.gov (United States)

    African swine fever virus (ASFV) is the etiological agent of a contagious and often lethal viral disease of domestic pigs that has significant economic consequences for swine breeding. The control of African Swine Fever (ASF) has been hampered by the unavailability of vaccines. Experimental vaccines...

  8. African swine fever virus Georgia isolate harboring deletions of MGF360 and MGF505 genes is attenuated in swine and confers protection against challenge with the virulent parental virus

    Science.gov (United States)

    African swine fever virus (ASFV) is the etiological agent of a contagious and often lethal disease of domestic pigs that has significant economic consequences for the swine industry. The control of African Swine Fever (ASF) has been hampered by the unavailability of vaccines. Experimental vaccines h...

  9. Risk of introducing African horse sickness virus into the Netherlands by international equine movements.

    Science.gov (United States)

    de Vos, C J; Hoek, C A; Nodelijk, G

    2012-09-15

    African horse sickness (AHS) is a vector-borne viral disease of equines that is transmitted by Culicoides spp. and can have severe consequences for the horse industry in affected territories. A study was performed to assess the risk of introducing AHS virus (AHSV) into the Netherlands (P_AHS) by international equine movements. The goal of this study was to provide more insight into (a) the regions and equine species that contribute most to this risk, (b) the seasonal variation in this risk, and (c) the effectiveness of measures to prevent introduction of AHSV. Countries worldwide were grouped into three risk regions: (1) high risk, i.e., those countries in which the virus is presumed to circulate, (2) low risk, i.e., those countries that have experienced outbreaks of AHS in the past and/or where the main vector of AHS, Culicoides imicola, is present, and (3) very low risk, i.e., all other countries. A risk model was constructed estimating P_AHS taking into account the probability of release of AHSV in the Netherlands and the probability that local vectors will subsequently transmit the virus to local hosts. Model calculations indicated that P_AHS is very low with a median value of 5.1×10(-4)/year. The risk is highest in July and August, while equine movements in the period October till March pose a negligible risk. High and low risk regions contribute most to P_AHS with 31% and 53%, respectively. Importations of donkeys and zebras constitute the highest risk of AHSV release from high risk regions, while international movements of competition horses constitute the highest risk of AHSV release from low and very low risk regions. Preventive measures currently applied reduce P_AHS by 46% if compared to a situation in which no preventive measures are applied. A prolonged and more effective quarantine period in high risk regions and more stringent import regulations for low risk regions could further reduce P_AHS. Large uncertainty was involved in estimating model input

  10. Family Wide Molecular Adaptations to Underground Life in African Mole-Rats Revealed by Phylogenomic Analysis.

    Science.gov (United States)

    Davies, Kalina T J; Bennett, Nigel C; Tsagkogeorga, Georgia; Rossiter, Stephen J; Faulkes, Christopher G

    2015-12-01

    During their evolutionary radiation, mammals have colonized diverse habitats. Arguably the subterranean niche is the most inhospitable of these, characterized by reduced oxygen, elevated carbon dioxide, absence of light, scarcity of food, and a substrate that is energetically costly to burrow through. Of all lineages to have transitioned to a subterranean niche, African mole-rats are one of the most successful. Much of their ecological success can be attributed to a diet of plant storage organs, which has allowed them to colonize climatically varied habitats across sub-Saharan Africa, and has probably contributed to the evolution of their diverse social systems. Yet despite their many remarkable phenotypic specializations, little is known about molecular adaptations underlying these traits. To address this, we sequenced the transcriptomes of seven mole-rat taxa, including three solitary species, and combined new sequences with existing genomic data sets. Alignments of more than 13,000 protein-coding genes encompassed, for the first time, all six genera and the full spectrum of ecological and social variation in the clade. We detected positive selection within the mole-rat clade and along ancestral branches in approximately 700 genes including loci associated with tumorigenesis, aging, morphological development, and sociality. By combining these results with gene ontology annotation and protein-protein networks, we identified several clusters of functionally related genes. This family wide analysis of molecular evolution in mole-rats has identified a suite of positively selected genes, deepening our understanding of the extreme phenotypic traits exhibited by this group.

  11. Adapting an evidence-based HIV prevention intervention for pregnant African-American women in substance abuse treatment

    Directory of Open Access Journals (Sweden)

    Winona Poulton

    2011-02-01

    Full Text Available Wendee M Wechsberg1, Felicia A Browne1, Winona Poulton1, Rachel Middlesteadt Ellerson1, Ashley Simons-Rudolph1, Deborah Haller2,  1RTI International,* Research Triangle Park, NC, USA; 2Columbia University College of Physicians and Surgeons, New York, NY, USA,  *RTI International is a trade name of Research Triangle InstituteAbstract: An adaptation of an evidence-based, woman-focused intervention designed to reduce HIV risk behaviors was conducted for pregnant, African-American women in substance abuse treatment in North Carolina. The intervention adaptation process included focus groups, expert panels, and the filming of women who spoke about their experiences with pregnancy, drug use, sex risk behaviors, HIV testing and treatment, need for substance abuse treatment, violence, and victimization. The assessment instrument was adapted for pregnant women and the intervention was organized into a 4-session PowerPoint presentation, with an additional session if a woman tested positive for HIV. All sessions and assessment instrument were installed on laptop computers for portability in treatment programs. We pilot tested our adaptation with 59 pregnant African-American women who had used an illicit drug within the past year and were enrolled in substance abuse treatment. At baseline, 41% were currently homeless, 76% were unemployed, 90% had not planned their current pregnancy, and approximately 70% reported drug use since finding out about the pregnancy. This sample of participants rated the intervention sessions and were highly satisfied with their experience, resulting in a mean satisfaction score of 6.5 out of 7. Pregnant African-American women who use drugs need substance abuse treatment that they do not currently access. Woman-focused HIV interventions help to address intersecting risk behaviors and need for treatment prevalent among this vulnerable group.Keywords: African-American woman, HIV prevention pregnancy, drug use, violence, sexual

  12. Assembly of Replication-Incompetent African Horse Sickness Virus Particles: Rational Design of Vaccines for All Serotypes

    Science.gov (United States)

    Lulla, Valeria; Lulla, Aleksei; Wernike, Kerstin; Aebischer, Andrea; Beer, Martin

    2016-01-01

    ABSTRACT African horse sickness virus (AHSV), an orbivirus in the Reoviridae family with nine different serotypes, causes devastating disease in equids. The virion particle is composed of seven proteins organized in three concentric layers, an outer layer made of VP2 and VP5, a middle layer made of VP7, and inner layer made of VP3 that encloses a replicase complex of VP1, VP4, and VP6 and a genome of 10 double-stranded RNA segments. In this study, we sought to develop highly efficacious candidate vaccines against all AHSV serotypes, taking into account not only immunogenic and safety properties but also virus productivity and stability parameters, which are essential criteria for vaccine candidates. To achieve this goal, we first established a highly efficient reverse genetics (RG) system for AHSV serotype 1 (AHSV1) and, subsequently, a VP6-defective AHSV1 strain in combination with in trans complementation of VP6. This was then used to generate defective particles of all nine serotypes, which required the exchange of two to five RNA segments to achieve equivalent titers of particles. All reassortant-defective viruses could be amplified and propagated to high titers in cells complemented with VP6 but were totally incompetent in any other cells. Furthermore, these replication-incompetent AHSV particles were demonstrated to be highly protective against homologous virulent virus challenges in type I interferon receptor (IFNAR)-knockout mice. Thus, these defective viruses have the potential to be used for the development of safe and stable vaccine candidates. The RG system also provides a powerful tool for the study of the role of individual AHSV proteins in virus assembly, morphogenesis, and pathogenesis. IMPORTANCE African horse sickness virus is transmitted by biting midges and causes African horse sickness in equids, with mortality reaching up to 95% in naive horses. Therefore, the development of efficient vaccines is extremely important due to major economic

  13. Comparisons of coat protein gene sequences show that East African isolates of Sweet potato feathery mottle virus form a genetically distinct group.

    Science.gov (United States)

    Kreuze, J F; Karyeija, R F; Gibson, R W; Valkonen, J P

    2000-01-01

    Sweet potato feathery mottle virus (SPFMV, genus Potyvirus) infects sweet potatoes (Ipomoea batatas) worldwide, but no sequence data on isolates from Africa are available. Coat protein (CP) gene sequences from eight East African isolates from Madagascar and different districts of Uganda (the second biggest sweet potato producer in the world) and two West African isolates from Nigeria and Niger were determined. They were compared by phylogenetic analysis with the previously reported sequences of ten SPFMV isolates from other continents. The East African SPFMV isolates formed a distinct cluster, whereas the other isolates were not clustered according to geographic origin. These data indicate that East African isolates of SPFMV form a genetically unique group.

  14. Association of the Host Immune Response with Protection Using a Live Attenuated African Swine Fever Virus Model

    Science.gov (United States)

    Carlson, Jolene; O’Donnell, Vivian; Alfano, Marialexia; Velazquez Salinas, Lauro; Holinka, Lauren G.; Krug, Peter W.; Gladue, Douglas P.; Higgs, Stephen; Borca, Manuel V.

    2016-01-01

    African swine fever (ASF) is a lethal hemorrhagic disease of swine caused by a double-stranded DNA virus, ASF virus (ASFV). There is no vaccine to prevent the disease and current control measures are limited to culling and restricting animal movement. Swine infected with attenuated strains are protected against challenge with a homologous virulent virus, but there is limited knowledge of the host immune mechanisms generating that protection. Swine infected with Pretoriuskop/96/4 (Pret4) virus develop a fatal severe disease, while a derivative strain lacking virulence-associated gene 9GL (Pret4Δ9GL virus) is completely attenuated. Swine infected with Pret4Δ9GL virus and challenged with the virulent parental virus at 7, 10, 14, 21, and 28 days post infection (dpi) showed a progressive acquisition of protection (from 40% at 7 dpi to 80% at 21 and 28 dpi). This animal model was used to associate the presence of host immune response (ASFV-specific antibody and interferon (IFN)-γ responses, or specific cytokine profiles) and protection against challenge. With the exception of ASFV-specific antibodies in survivors challenged at 21 and 28 dpi, no association between the parameters assessed and protection could be established. These results, encompassing data from 65 immunized swine, underscore the complexity of the system under study, suggesting that protection relies on the concurrence of different host immune mechanisms. PMID:27782090

  15. Association of the Host Immune Response with Protection Using a Live Attenuated African Swine Fever Virus Model

    Directory of Open Access Journals (Sweden)

    Jolene Carlson

    2016-10-01

    Full Text Available African swine fever (ASF is a lethal hemorrhagic disease of swine caused by a double-stranded DNA virus, ASF virus (ASFV. There is no vaccine to prevent the disease and current control measures are limited to culling and restricting animal movement. Swine infected with attenuated strains are protected against challenge with a homologous virulent virus, but there is limited knowledge of the host immune mechanisms generating that protection. Swine infected with Pretoriuskop/96/4 (Pret4 virus develop a fatal severe disease, while a derivative strain lacking virulence-associated gene 9GL (Pret4Δ9GL virus is completely attenuated. Swine infected with Pret4Δ9GL virus and challenged with the virulent parental virus at 7, 10, 14, 21, and 28 days post infection (dpi showed a progressive acquisition of protection (from 40% at 7 dpi to 80% at 21 and 28 dpi. This animal model was used to associate the presence of host immune response (ASFV-specific antibody and interferon (IFN-γ responses, or specific cytokine profiles and protection against challenge. With the exception of ASFV-specific antibodies in survivors challenged at 21 and 28 dpi, no association between the parameters assessed and protection could be established. These results, encompassing data from 65 immunized swine, underscore the complexity of the system under study, suggesting that protection relies on the concurrence of different host immune mechanisms.

  16. DNA vaccination partially protects against African swine fever virus lethal challenge in the absence of antibodies.

    Directory of Open Access Journals (Sweden)

    Jordi M Argilaguet

    Full Text Available The lack of available vaccines against African swine fever virus (ASFV means that the evaluation of new immunization strategies is required. Here we show that fusion of the extracellular domain of the ASFV Hemagglutinin (sHA to p54 and p30, two immunodominant structural viral antigens, exponentially improved both the humoral and the cellular responses induced in pigs after DNA immunization. However, immunization with the resulting plasmid (pCMV-sHAPQ did not confer protection against lethal challenge with the virulent E75 ASFV-strain. Due to the fact that CD8(+ T-cell responses are emerging as key components for ASFV protection, we designed a new plasmid construct, pCMV-UbsHAPQ, encoding the three viral determinants above mentioned (sHA, p54 and p30 fused to ubiquitin, aiming to improve Class I antigen presentation and to enhance the CTL responses induced. As expected, immunization with pCMV-UbsHAPQ induced specific T-cell responses in the absence of antibodies and, more important, protected a proportion of immunized-pigs from lethal challenge with ASFV. In contrast with control pigs, survivor animals showed a peak of CD8(+ T-cells at day 3 post-infection, coinciding with the absence of viremia at this time point. Finally, an in silico prediction of CTL peptides has allowed the identification of two SLA I-restricted 9-mer peptides within the hemagglutinin of the virus, capable of in vitro stimulating the specific secretion of IFNγ when using PBMCs from survivor pigs. Our results confirm the relevance of T-cell responses in protection against ASF and open new expectations for the future development of more efficient recombinant vaccines against this disease.

  17. DNA vaccination partially protects against African swine fever virus lethal challenge in the absence of antibodies.

    Science.gov (United States)

    Argilaguet, Jordi M; Pérez-Martín, Eva; Nofrarías, Miquel; Gallardo, Carmina; Accensi, Francesc; Lacasta, Anna; Mora, Mercedes; Ballester, Maria; Galindo-Cardiel, Ivan; López-Soria, Sergio; Escribano, José M; Reche, Pedro A; Rodríguez, Fernando

    2012-01-01

    The lack of available vaccines against African swine fever virus (ASFV) means that the evaluation of new immunization strategies is required. Here we show that fusion of the extracellular domain of the ASFV Hemagglutinin (sHA) to p54 and p30, two immunodominant structural viral antigens, exponentially improved both the humoral and the cellular responses induced in pigs after DNA immunization. However, immunization with the resulting plasmid (pCMV-sHAPQ) did not confer protection against lethal challenge with the virulent E75 ASFV-strain. Due to the fact that CD8(+) T-cell responses are emerging as key components for ASFV protection, we designed a new plasmid construct, pCMV-UbsHAPQ, encoding the three viral determinants above mentioned (sHA, p54 and p30) fused to ubiquitin, aiming to improve Class I antigen presentation and to enhance the CTL responses induced. As expected, immunization with pCMV-UbsHAPQ induced specific T-cell responses in the absence of antibodies and, more important, protected a proportion of immunized-pigs from lethal challenge with ASFV. In contrast with control pigs, survivor animals showed a peak of CD8(+) T-cells at day 3 post-infection, coinciding with the absence of viremia at this time point. Finally, an in silico prediction of CTL peptides has allowed the identification of two SLA I-restricted 9-mer peptides within the hemagglutinin of the virus, capable of in vitro stimulating the specific secretion of IFNγ when using PBMCs from survivor pigs. Our results confirm the relevance of T-cell responses in protection against ASF and open new expectations for the future development of more efficient recombinant vaccines against this disease.

  18. A Characterization of Aerosolized Sudan Virus Infection in African Green Monkeys, Cynomolgus Macaques, and Rhesus Macaques

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    Donald K. Nichols

    2012-10-01

    Full Text Available Filoviruses are members of the genera Ebolavirus, Marburgvirus, and “Cuevavirus”. Because they cause human disease with high lethality and could potentially be used as a bioweapon, these viruses are classified as CDC Category A Bioterrorism Agents. Filoviruses are relatively stable in aerosols, retain virulence after lyophilization, and can be present on contaminated surfaces for extended periods of time. This study explores the characteristics of aerosolized Sudan virus (SUDV Boniface in non-human primates (NHP belonging to three different species. Groups of cynomolgus macaques (cyno, rhesus macaques (rhesus, and African green monkeys (AGM were challenged with target doses of 50 or 500 plaque-forming units (pfu of aerosolized SUDV. Exposure to either viral dose resulted in increased body temperatures in all three NHP species beginning on days 4–5 post-exposure. Other clinical findings for all three NHP species included leukocytosis, thrombocytopenia, anorexia, dehydration, and lymphadenopathy. Disease in all of the NHPs was severe beginning on day 6 post-exposure, and all animals except one surviving rhesus macaque were euthanized by day 14. Serum alanine transaminase (ALT and aspartate transaminase (AST concentrations were elevated during the course of disease in all three species; however, AGMs had significantly higher ALT and AST concentrations than cynos and rhesus. While all three species had detectable viral load by days 3-4 post exposure, Rhesus had lower average peak viral load than cynos or AGMs. Overall, the results indicate that the disease course after exposure to aerosolized SUDV is similar for all three species of NHP.

  19. Replication and transmission of mammalian-adapted H9 subtype influenza virus in pigs and quail.

    Science.gov (United States)

    Obadan, Adebimpe O; Kimble, Brian J; Rajao, Daniela; Lager, Kelly; Santos, Jefferson J S; Vincent, Amy; Perez, Daniel R

    2015-09-01

    Influenza A virus is a major pathogen of birds, swine and humans. Strains can jump between species in a process often requiring mutations and reassortment, resulting in outbreaks and, potentially, pandemics. H9N2 avian influenza is predominant in poultry across Asia and occasionally infects humans and swine. Pandemic H1N1 (H1N1pdm) is endemic in humans and swine and has a history of reassortment in pigs. Previous studies have shown the compatibility of H9N2 and H1N1pdm for reassortment in ferrets, a model for human infection and transmission. Here, the effects of ferret adaptation of H9 surface gene segments on the infectivity and transmission in at-risk natural hosts, specifically swine and quail, were analysed. Reassortant H9N1 and H9N2 viruses, carrying seven or six gene segments from H1N1pdm, showed infectivity and transmissibility in swine, unlike the wholly avian H9N2 virus with ferret-adapted surface genes. In quail, only the reassortant H9N2 with the six internal gene segments from the H1N1pdm strain was able to infect and transmit, although less efficiently than the wholly avian H9N2 virus with ferret-adapted surface genes. These results highlight that ferret-adapted mutations on the haemagglutinin of H9 subtype virus do not restrict the ability of the virus to infect swine and quail, and that the ability to transmit in these species depends on the context of the whole virus. As such, this study emphasizes the threat that H9N2 reassortant viruses pose to humans and agricultural species and the importance of the genetic constellation of the virus to its ability to replicate and transmit in natural hosts of influenza.

  20. Evidence of hemolysis in pigs infected with highly virulent African swine fever virus

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    Zaven Karalyan

    2016-12-01

    Full Text Available Aim: The research was conducted to understand more profoundly the pathogenetic aspects of the acute form of the African swine fever (ASF. Materials and Methods: A total of 10 pigs were inoculated with ASF virus (ASFV (genotype II in the study of the red blood cells (RBCs, blood and urine biochemistry in the dynamics of disease. Results: The major hematological differences observed in ASFV infected pigs were that the mean corpuscular volume, mean corpuscular hemoglobin, and hematocrits were significantly decreased compared to controls, and the levels of erythropoietin were significantly increased. Also were detected the trends of decrease in RBC count at terminal stages of ASF. Analysis of blood biochemistry revealed that during ASF development, besides bilirubinemia significantly elevated levels of lactate dehydrogenase, and aspartate aminotransferase were detected. Analysis of urine biochemistry revealed the presence of bilirubinuria, proteinuria during ASF development. Proteinuria, especially at late stages of the disease reflects a severe kidney damage possible glomerulonefritis. Conclusion: The results of this study indicate the characteristics of developing hemolytic anemia observed in acute ASF (genotype II.

  1. Genetic characterization of African swine fever viruses from a 2008 outbreak in Tanzania.

    Science.gov (United States)

    Misinzo, G; Magambo, J; Masambu, J; Yongolo, M G; Van Doorsselaere, J; Nauwynck, H J

    2011-02-01

    Outbreaks of African swine fever (ASF) have been reported in the past from several countries in sub-Saharan Africa. The aim of this study was to genotype ASF viruses (ASFVs) from the 2008 outbreak in Morogoro and Dar es Salaam regions of Tanzania. Tissue samples from domestic pigs that died as a result of severe haemorrhagic disease were collected and analysed with PCR and genome sequencing methods using ASFV-specific primer sets. Nucleotide sequence data were obtained for the B646L (p72), E183L (p54) and the variable region of the B602L gene sequences. Phylogenetic analyses based on DNA sequences showed that the 2008 Tanzanian isolates belonged to p72 genotype XV and clustered together with those derived from the 2001 outbreak in Tanzania. Analysis of the tetrameric amino acid repeat regions within the variable region of the B602L gene showed that the repeat signature of the 2008 Tanzanian ASFV was unique and contained three novel tetramers (U = NIDT/NTDT and X = NTDI). Epidemiological investigation suggested that transportation of live pigs continues to play an active role in the epidemiology of ASF in Tanzania. It is recommended that future control of ASF spread in Tanzania should focus on the early detection and confirmation of the disease, prompt institution of quarantine measures, culling and proper disposal of infected and in-contact animals and decontamination of affected premises.

  2. Modern adjuvants do not enhance the efficacy of an inactivated African swine fever virus vaccine preparation.

    Science.gov (United States)

    Blome, Sandra; Gabriel, Claudia; Beer, Martin

    2014-06-30

    African swine fever (ASF) is among the most devastating viral diseases of pigs. In recent years, the disease has spread alarmingly. Despite intensive research activities, promising vaccine candidates are still lacking. For this reason, a study was undertaken to re-assess inactivated ASFV preparations with state-of-the-art adjuvants. Inactivated preparations of ASF virus (ASFV) "Armenia08" were adjuvanted with either Polygen™ or Emulsigen(®)-D, respectively, and used to immunize six weaner pigs two times with a three-week interval. Six weeks after the first immunization, animals were challenged with the homologues highly virulent ASFV. Although ASFV-specific antibodies were detectable in all but one vaccinated animal prior to challenge, no protective effect of immunization was observed. All animals developed acute-lethal ASF and had to be euthanized within eleven days post challenge. A slightly accelerated clinical course in vaccinees could even indicate an antibody dependent enhancement, which could also influence efficacy of other vaccine approaches.

  3. Evidence of hemolysis in pigs infected with highly virulent African swine fever virus

    Science.gov (United States)

    Karalyan, Zaven; Zakaryan, Hovakim; Arakelova, Elina; Aivazyan, Violeta; Tatoyan, Marina; Kotsinyan, Armen; Izmailyan, Roza; Karalova, Elena

    2016-01-01

    Aim: The research was conducted to understand more profoundly the pathogenetic aspects of the acute form of the African swine fever (ASF). Materials and Methods: A total of 10 pigs were inoculated with ASF virus (ASFV) (genotype II) in the study of the red blood cells (RBCs), blood and urine biochemistry in the dynamics of disease. Results: The major hematological differences observed in ASFV infected pigs were that the mean corpuscular volume, mean corpuscular hemoglobin, and hematocrits were significantly decreased compared to controls, and the levels of erythropoietin were significantly increased. Also were detected the trends of decrease in RBC count at terminal stages of ASF. Analysis of blood biochemistry revealed that during ASF development, besides bilirubinemia significantly elevated levels of lactate dehydrogenase, and aspartate aminotransferase were detected. Analysis of urine biochemistry revealed the presence of bilirubinuria, proteinuria during ASF development. Proteinuria, especially at late stages of the disease reflects a severe kidney damage possible glomerulonefritis. Conclusion: The results of this study indicate the characteristics of developing hemolytic anemia observed in acute ASF (genotype II). PMID:28096614

  4. Epistatic roles of E2 glycoprotein mutations in adaption of chikungunya virus to Aedes albopictus and Ae. aegypti mosquitoes.

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    Konstantin A Tsetsarkin

    Full Text Available Between 2005 and 2007 Chikungunya virus (CHIKV caused its largest outbreak/epidemic in documented history. An unusual feature of this epidemic is the involvement of Ae. albopictus as a principal vector. Previously we have demonstrated that a single mutation E1-A226V significantly changed the ability of the virus to infect and be transmitted by this vector when expressed in the background of well characterized CHIKV strains LR2006 OPY1 and 37997. However, in the current study we demonstrate that introduction of the E1-A226V mutation into the background of an infectious clone derived from the Ag41855 strain (isolated in Uganda in 1982 does not significantly increase infectivity for Ae. albopictus. In order to elucidate the genetic determinants that affect CHIKV sensitivity to the E1-A226V mutation in Ae. albopictus, the genomes of the LR2006 OPY1 and Ag41855 strains were used for construction of chimeric viruses and viruses with a specific combination of point mutations at selected positions. Based upon the midgut infection rates of the derived viruses in Ae. albopictus and Ae. aegypti mosquitoes, a critical role of the mutations at positions E2-60 and E2-211 on vector infection was revealed. The E2-G60D mutation was an important determinant of CHIKV infectivity for both Ae. albopictus and Ae. aegypti, but only moderately modulated the effect of the E1-A226V mutation in Ae. albopictus. However, the effect of the E2-I211T mutation with respect to mosquito infections was much more specific, strongly modifying the effect of the E1-A226V mutation in Ae. albopictus. In contrast, CHIKV infectivity for Ae. aegypti was not influenced by the E2-1211T mutation. The occurrence of the E2-60G and E2-211I residues among CHIKV isolates was analyzed, revealing a high prevalence of E2-211I among strains belonging to the Eastern/Central/South African (ECSA clade. This suggests that the E2-211I might be important for adaptation of CHIKV to some particular conditions

  5. Types of variation in DNA-A among isolates of East African cassava mosaic virus from Kenya, Malawi and Tanzania.

    Science.gov (United States)

    Zhou, X; Robinson, D J; Harrison, B D

    1998-11-01

    Complete nucleotide sequences of the DNA-A-like molecules of three East African cassava mosaic virus (EACMV) isolates from Kenya (-K, 2801 nt) and Malawi (-MH and -MK, both 2804 nt) were determined. These sequences were compared with that published for a Tanzanian isolate (-T, 2801 nt) and the partial sequence of a third Malawian isolate. Intergenic region sequences of all isolates, and deduced amino acid sequences of their AC1 (Rep) proteins, each formed a tightly related cluster that was distinct from the comparable components of other begomoviruses. Other complementary-sense genes (AC2, AC3, AC4) differed between EACMV isolates in a way consistent with the accumulation of point mutations. In contrast, virus-sense genes (CP, AV2) of isolates -MH and -MK differed (substantially for AV2) from those of other EACMV isolates but somewhat resembled those of tomato yellow leaf curl virus-Israel, suggesting they had been acquired by recombination with an unidentified begomovirus.

  6. Biological characterization of African swine fever virus genotype II strains from north-eastern Estonia in European wild boar.

    Science.gov (United States)

    Nurmoja, I; Petrov, A; Breidenstein, C; Zani, L; Forth, J H; Beer, M; Kristian, M; Viltrop, A; Blome, S

    2017-01-24

    Due to its impact on animal health and pig industry, African swine fever (ASF) is regarded as one of the most important viral diseases of pigs. Following the ongoing epidemic in the Transcaucasian countries and the Russian Federation, African swine fever virus was introduced into the Estonian wild boar population in 2014. Epidemiological investigations suggested two different introductions into the southern and the north-eastern part of Estonia. Interestingly, outbreak characteristics varied considerably between the affected regions. While high mortality and mainly virus-positive animals were observed in the southern region, mortality was low in the north-eastern area. In the latter, clinically healthy, antibody-positive animals were found in the hunting bag and detection of virus was rare. Two hypotheses could explain the different behaviour in the north-east: (i) the frequency of antibody detections combined with the low mortality is the tail of an older, so far undetected epidemic wave coming from the east, or (ii) the virus in this region is attenuated and leads to a less severe clinical outcome. To explore the possibility of virus attenuation, a re-isolated ASFV strain from the north-eastern Ida-Viru region was biologically characterized in European wild boar. Oronasal inoculation led to an acute and severe disease course in all animals with typical pathomorphological lesions. However, one animal recovered completely and was subsequently commingled with three sentinels of the same age class to assess disease transmission. By the end of the trial at 96 days post-initial inoculation, all animals were completely healthy and neither virus nor viral genomes were detected in the sentinels or the survivor. The survivor, however, showed high antibody levels. In conclusion, the ASFV strain from north-eastern Estonia was still highly virulent but nevertheless, one animal recovered completely. Under the experimental conditions, no transmission occurred from the survivor

  7. African Swine Fever Virus Undergoes Outer Envelope Disruption, Capsid Disassembly and Inner Envelope Fusion before Core Release from Multivesicular Endosomes.

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    Bruno Hernáez

    2016-04-01

    Full Text Available African swine fever virus (ASFV is a nucleocytoplasmic large DNA virus (NCLDV that causes a highly lethal disease in domestic pigs. As other NCLDVs, the extracellular form of ASFV possesses a multilayered structure consisting of a genome-containing nucleoid successively wrapped by a thick protein core shell, an inner lipid membrane, an icosahedral protein capsid and an outer lipid envelope. This structural complexity suggests an intricate mechanism of internalization in order to deliver the virus genome into the cytoplasm. By using flow cytometry in combination with pharmacological entry inhibitors, as well as fluorescence and electron microscopy approaches, we have dissected the entry and uncoating pathway used by ASFV to infect the macrophage, its natural host cell. We found that purified extracellular ASFV is internalized by both constitutive macropinocytosis and clathrin-mediated endocytosis. Once inside the cell, ASFV particles move from early endosomes or macropinosomes to late, multivesicular endosomes where they become uncoated. Virus uncoating requires acidic pH and involves the disruption of the outer membrane as well as of the protein capsid. As a consequence, the inner viral membrane becomes exposed and fuses with the limiting endosomal membrane to release the viral core into the cytosol. Interestingly, virus fusion is dependent on virus protein pE248R, a transmembrane polypeptide of the inner envelope that shares sequence similarity with some members of the poxviral entry/fusion complex. Collective evidence supports an entry model for ASFV that might also explain the uncoating of other multienveloped icosahedral NCLDVs.

  8. African Swine Fever Virus Undergoes Outer Envelope Disruption, Capsid Disassembly and Inner Envelope Fusion before Core Release from Multivesicular Endosomes

    Science.gov (United States)

    Hernáez, Bruno; Guerra, Milagros; Salas, María L.

    2016-01-01

    African swine fever virus (ASFV) is a nucleocytoplasmic large DNA virus (NCLDV) that causes a highly lethal disease in domestic pigs. As other NCLDVs, the extracellular form of ASFV possesses a multilayered structure consisting of a genome-containing nucleoid successively wrapped by a thick protein core shell, an inner lipid membrane, an icosahedral protein capsid and an outer lipid envelope. This structural complexity suggests an intricate mechanism of internalization in order to deliver the virus genome into the cytoplasm. By using flow cytometry in combination with pharmacological entry inhibitors, as well as fluorescence and electron microscopy approaches, we have dissected the entry and uncoating pathway used by ASFV to infect the macrophage, its natural host cell. We found that purified extracellular ASFV is internalized by both constitutive macropinocytosis and clathrin-mediated endocytosis. Once inside the cell, ASFV particles move from early endosomes or macropinosomes to late, multivesicular endosomes where they become uncoated. Virus uncoating requires acidic pH and involves the disruption of the outer membrane as well as of the protein capsid. As a consequence, the inner viral membrane becomes exposed and fuses with the limiting endosomal membrane to release the viral core into the cytosol. Interestingly, virus fusion is dependent on virus protein pE248R, a transmembrane polypeptide of the inner envelope that shares sequence similarity with some members of the poxviral entry/fusion complex. Collective evidence supports an entry model for ASFV that might also explain the uncoating of other multienveloped icosahedral NCLDVs. PMID:27110717

  9. African Swine Fever Diagnosis Adapted to Tropical Conditions by the Use of Dried-blood Filter Papers.

    Science.gov (United States)

    Randriamparany, T; Kouakou, K V; Michaud, V; Fernández-Pinero, J; Gallardo, C; Le Potier, M-F; Rabenarivahiny, R; Couacy-Hymann, E; Raherimandimby, M; Albina, E

    2016-08-01

    The performance of Whatman 3-MM filter papers for the collection, drying, shipment and long-term storage of blood at ambient temperature, and for the detection of African swine fever virus and antibodies was assessed. Conventional and real-time PCR, viral isolation and antibody detection by ELISA were performed on paired samples (blood/tissue versus dried-blood 3-MM filter papers) collected from experimentally infected pigs and from farm pigs in Madagascar and Côte d'Ivoire. 3-MM filter papers were used directly in the conventional and real-time PCR without previous extraction of nucleic acids. Tests that performed better with 3-MM filter papers were in descending order: virus isolation, real-time UPL PCR and conventional PCR. The analytical sensitivity of real-time UPL PCR on filter papers was similar to conventional testing (virus isolation or conventional PCR) on organs or blood. In addition, blood-dried filter papers were tested in ELISA for antibody detection and the observed sensitivity was very close to conventional detection on serum samples and gave comparable results. Filter papers were stored up to 9 months at 20-25°C and for 2 months at 37°C without significant loss of sensitivity for virus genome detection. All tests on 3-MM filter papers had 100% specificity compared to the gold standards. Whatman 3-MM filter papers have the advantage of being cheap and of preserving virus viability for future virus isolation and characterization. In this study, Whatman 3-MM filter papers proved to be a suitable support for the collection, storage and use of blood in remote areas of tropical countries without the need for a cold chain and thus provide new possibilities for antibody testing and virus isolation.

  10. Viremia and antibody response of small African and laboratory animals to Crimean-Congo hemorrhagic fever virus infection.

    Science.gov (United States)

    Shepherd, A J; Leman, P A; Swanepoel, R

    1989-05-01

    Eleven species of small African wild mammals, laboratory rabbits, guinea pigs, and Syrian hamsters were infected with Crimean-Congo hemorrhagic fever (CCHF) virus. Low-titered viremia followed by development of antibody was observed in scrub hares (Lepus saxatilis), Cape ground squirrels (Xerus inauris), red veld rats (Aethomys chrysophilus), white tailed rats (Mystromys albicaudatus), bushveld gerbils (Tatera leucogaster), striped mice (Rhabdomys pumilio), and guinea pigs. The maximum viremic titer in 4 scrub hares was 10(1.7-4.2) 50% mouse lethal doses/ml. Viremia was detected in 1/17 infected laboratory rabbits. Antibody response was only detected in South African hedgehogs (Atelerix frontalis), highveld gerbils (T. brantsii), Namaqua gerbils (Desmodillus auricularis), 2 species of multimammate mouse (Mastomys natalensis and M. coucha), and Syrian hamsters. The results of the study indicate that a proportion of infected scrub hares develop CCHF viremia of an intensity shown in the Soviet Union to be sufficient for infection of feeding immature ixodid ticks, but that South African hedgehogs and wild rodents are unlikely to be of importance as maintenance hosts of the virus in southern Africa.

  11. Applying adaptive management in resource use in South African National Parks: A case study approach

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    Kelly Scheepers

    2011-05-01

    Full Text Available South African National Parks (SANParks has a history of formal and informal natural resource use that is characterised by polarised views on national conservation interests and benefits to communities. Current efforts aim to determine the sustainability of existing resource use in parks and to formalise these activities through the development of resource use protocols. The resource use policy of SANParks outlines principles for sustainable resource use, including greater involvement of local communities in management of protected areas and an adaptive management approach to determining sustainable use levels. This paper examines three case studies on plant use in national parks with regard to the development of criteria and indicators for monitoring resource use, and the role of thresholds of potential concern in measuring effectiveness of managing for sustainable use levels. Opportunities and challenges for resource use management are identified. Findings show that platforms for discussion and knowledge sharing, including research committees and community associations, are critical to building relationships, trust and a shared vision of sustainable resource use between stakeholders. However, additional capacity building is needed to enable local community structures to manage internal social conflicts and jealousy, and to participate fully in monitoring efforts. Long-term monitoring is essential for developing flexible harvest prescriptions for plant use, but this is a time-consuming and resource-intensive exercise. Flexible management strategies are difficult to implement and sometimes command-and-control measures are necessary to protect rare or endangered species. A holistic approach that considers resource use in national parks as a complement to broader community development initiatives offers a way forward.Conservation implications: There is no blueprint for the development of sustainable resource use systems and resource use is often

  12. Virus-specific CD8⁺ T-cells detected in PBMC from horses vaccinated against African horse sickness virus.

    Science.gov (United States)

    Pretorius, Alri; Van Kleef, Mirinda; Van Wyngaardt, Wouter; Heath, Jeanette

    2012-03-15

    African horsesickness (AHS) is an infectious but noncontagious viral disease affecting all species of Equidae. The recall immune response of AHSV naïve horses immunised with an attenuated African horsesickness virus serotype 4 (AHSV4) was characterised using immune assays including ELISPOT, real-time PCR (qPCR) and flow cytometry. The recall immune response detected in PBMC isolated from three inoculated horses showed an upregulation of circulating B lymphocytes that correlated with elevated IL-4 mRNA expression indicative of humoral immunity, but reduced frequency of CD4⁺ cells. In addition to the expected antibody response, an increase in CD8⁺ cells was also detected. Although these CD8⁺ cells may be CTL, the role of these cells in immunity against AHSV still has to be determined.

  13. Vaccination of horses with a recombinant modified vaccinia Ankara virus (MVA) expressing African horse sickness (AHS) virus major capsid protein VP2 provides complete clinical protection against challenge.

    Science.gov (United States)

    Alberca, Berta; Bachanek-Bankowska, Katarzyna; Cabana, Marta; Calvo-Pinilla, Eva; Viaplana, Elisenda; Frost, Lorraine; Gubbins, Simon; Urniza, Alicia; Mertens, Peter; Castillo-Olivares, Javier

    2014-06-17

    African horse sickness virus (AHSV) is an arthropod-borne pathogen that infects all species of equidae and causes high mortality in horses. Previously, a recombinant modified vaccinia Ankara (MVA) virus expressing the protein VP2 of AHSV serotype 4 was shown to induce virus neutralising antibodies in horses and protected interferon alpha receptor gene knock-out mice (IFNAR -/-) against virulent AHSV challenge. This study builds on the previous work, examining the protective efficacy of MVA-VP2 vaccination in the natural host of AHSV infection. A study group of 4 horses was vaccinated twice with a recombinant MVA virus expressing the major capsid protein (VP2) of AHSV serotype 9. Vaccinated animals and a control group of unvaccinated horses were then challenged with a virulent strain of AHSV-9. The vaccinated animals were completely protected against clinical disease and also against viraemia as measured by standard end-point dilution assays. In contrast, all control horses presented viraemia after challenge and succumbed to the infection. These results demonstrate the potential of recombinant MVA viruses expressing the outer capsid VP2 of AHSV as a protective vaccine against AHSV infection in the field.

  14. Beak and feather disease virus haemagglutinating activity using erythrocytes from African Grey parrots and Brown-headed parrots : research communication

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    K. Kondiah

    2005-09-01

    Full Text Available Psittacine beak and feather disease (PBFD is a common viral disease of wild and captive psittacine birds characterized by symmetric feather loss and beak deformities. The causative agent, beak and feather disease virus (BFDV, is a small, circular single-stranded DNA virus that belongs to the genus Circovirus. BFDV can be detected by PCR or the use of haemagglutination (HA and haemagglutination inhibition (HI assays that detect antigen and antibodies respectively. Erythrocytes from a limited number of psittacine species of Australian origin can be used in these tests. In South Africa, the high cost of these birds makes them difficult to obtain for experimental purposes. Investigation into the use of erythrocytes from African Grey parrots and Brown-headed parrots yielded positive results showing the haemagglutinating activity of their erythrocytes with purified BFDV obtained from confirmed clinical cases of the disease. The HA activity was further confirmed by the demonstration of HI using BFDV antiserum from three different African Grey parrots previously exposed to the virus and not showing clinical signs of the disease.

  15. Complete nucleotide sequence and host range of South African cassava mosaic virus: further evidence for recombination amongst begomoviruses.

    Science.gov (United States)

    Berrie, L C; Rybicki, E P; Rey, M E

    2001-01-01

    Complete nucleotide sequences of the DNA-A (2800 nt) and DNA-B (2760 nt) components of a novel cassava-infecting begomovirus, South African cassava mosaic virus (SACMV), were determined and compared with various New World and Old World begomoviruses. SACMV is most closely related to East African cassava mosaic virus (EACMV) in both its DNA-A (85% with EACMV-MH and -MK) and -B (90% with EACMV-UG2-Mld and EACMV-UG3-Svr) components; however, percentage sequence similarities of less than 90% in the DNA-A component allowed SACMV to be considered a distinct virus. One significant recombination event spanning the entire AC4 open reading frame was identified; however, there was no evidence of recombination in the DNA-B component. Infectivity of the cloned SACMV genome was demonstrated by successful agroinoculation of cassava and three other plant species (Phaseolus vulgaris, Malva parviflora and Nicotiana benthamiana). This is the first description of successful infection of cassava with a geminivirus using Agrobacterium tumefaciens.

  16. The persistence of African swine fever virus in field-infected Ornithodoros erraticus during the ASF endemic period in Portugal.

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    Fernando S Boinas

    Full Text Available African swine fever (ASF is an important disease of pigs and outbreaks of ASF have occurred in Europe on multiple occasions. To explore the period for which the European soft tick species Ornithodoros erraticus (Acari: Argasidae is able to act as a reservoir of African swine fever virus (ASFV after infected hosts are removed, we collected specimens from farms in the provinces of Alentejo and Algarve in Portugal during the endemic period and tested them subsequently using cell culture and experimental infection. We show that ticks from previously infected farms may contain infectious virus for at least five years and three months after the removal of infectious hosts. Furthermore, in two cases infectious virus was successfully isolated from ticks on restocked farms that had not yet suffered a re-emergence of disease. Experimental transmission to pigs was demonstrated in batches tested up to 380 days after an outbreak. These results clarify the epidemiological role of O. erraticus ticks in the persistence of ASFV in the field, provide additional evidence to support its role in the re-emergence of a sporadic outbreak of ASF in Portugal in 1999 and suggest that the current quarantine legislation and restocking advice when these ticks are present on the pig farm premises is appropriate.

  17. Development of a Rapid and Sensitive Method for Detection of African Swine Fever Virus Using Loop-Mediated Isothermal Amplification

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    Xulong Wu

    Full Text Available ABSTRACT A loop-mediated isothermal amplification (LAMP assay was developed for rapid, sensitive and specific detection of African swine fever virus (ASFV. A set of LAMP primers was designed based on the sequence of the ASFV gene K205R. Reaction temperature and time were optimized to 64 oC and 60 min, respectively. LAMP products were detected by agarose gel electrophoresis or visually with the addition of fluorescent dye. The detection limit of the LAMP assay was approximately 6 copies of the target gene per microliter, 100 times more sensitive than conventional PCR. LAMP is a simple and inexpensive molecular assay format for ASFV detection. To date, African swine fever has not been reported in China. LAMP can be used to monitor ASFV spread into China, thereby reducing the threat of ASF.

  18. Emerging rabbit haemorrhagic disease virus 2 (RHDV2) at the gates of the African continent.

    Science.gov (United States)

    Martin-Alonso, Aarón; Martin-Carrillo, Natalia; Garcia-Livia, Katherine; Valladares, Basilio; Foronda, Pilar

    2016-10-01

    Until the beginning of this decade, the genetic characterization of rabbit haemorrhagic disease virus (RHDV) from Iberian Peninsula had revealed the existence of two genogroups, G1 and sporadically G6. In 2010, the new emerging rabbit haemorrhagic disease variant, RHDV2 or RHDVb, was described in France, from where it has rapidly spread throughout Europe, including Iberian Peninsula countries. Nevertheless, although cases of rabbit haemorrhagic disease (RHD) have been reported in the Canary Islands, a Spanish archipelago located 100km off the coast of Morocco, no genetic characterization of RHDV had been carried out. Consequently, in order to identify the circulating RHDV strains in this archipelago, liver samples of six farm rabbits and fifteen wild rabbits were collected from several areas of the largest island, Tenerife, and analyzed for the presence of RHDV by antigen capture double antibody sandwich ELISA. In case of positive ELISA result, we amplified and sequenced two fragments of the vp60 gene, which were concatenated for phylogenetic purposes. The sequences analysis revealed the presence of RHDV2 in both farm and wild rabbits from several areas of Tenerife. This result constitutes the first finding of RHDV2 in the Canary Islands. These RHDV2 strains found in Tenerife shared two exclusive SNPs that have not been observed in the rest of RHDV2 strains. The identification of RHDV2 and the absence of classic RHDV strains in this study suggest that RHDV2 may be replacing classic strains in Tenerife, as has been also proposed in Iberian Peninsula, France and Azores. Given the proximity of the Canary Islands to the African continent, this result should raise awareness about a possible dispersal of RHDV2 from the Canary Islands to the North of Africa.

  19. Hepatitis B virus subgenotype A1: evolutionary relationships between Brazilian, African and Asian isolates.

    Directory of Open Access Journals (Sweden)

    Bárbara V Lago

    Full Text Available Brazil is a country of low hepatitis B virus (HBV endemicity in which the genotype A of HBV (HBV/A is the most prevalent. The complete nucleotide sequences of 26 HBV/A isolates, originating from eight Brazilian states, were determined. All were adw2. Twenty-three belonged to subgenotype A1 and three to A2. By phylogenetic analysis, it was shown that all the 23 HBV/A1 isolates clustered together with isolates from Bangladesh, India, Japan, Nepal, the Philippines and United Arab Emirates, but not with those of Congo, Kenya, Malawi, Rwanda, South Africa, Tanzania, Uganda and Zimbabwe. Four amino acid residues in the polymerase (His138 in the terminal protein domain, Pro18 and His90 in the spacer, and Ser109 in the reverse transcriptase, and one (Phe17 in the precore region, predominated in Latin American and Asian HBV/A1 isolates, but were rarely encountered in African isolates, with the exception of those from Somalia. Specific variations of two adjacent amino acids in the C-terminal domain of the HBx protein, namely Ala146 and Pro147, were found in all the Brazilian, but rarely in the other HBV/A1 isolates. By Bayesian analysis, the existence of an 'Asian-American' clade within subgenotype A1 was supported by a posterior probability value of 0.996. The close relatedness of the Brazilian, Asian and Somalian isolates suggests that the HBV/A1 strains predominant in Brazil did not originate from the five million slaves who were imported from Central and Western Africa from 1551 to 1840, but rather from the 300-400,000 captives forcibly removed from southeast Africa at the middle of the 19th century.

  20. Hepatitis B virus subgenotype A1: evolutionary relationships between Brazilian, African and Asian isolates.

    Science.gov (United States)

    Lago, Bárbara V; Mello, Francisco C; Kramvis, Anna; Niel, Christian; Gomes, Selma A

    2014-01-01

    Brazil is a country of low hepatitis B virus (HBV) endemicity in which the genotype A of HBV (HBV/A) is the most prevalent. The complete nucleotide sequences of 26 HBV/A isolates, originating from eight Brazilian states, were determined. All were adw2. Twenty-three belonged to subgenotype A1 and three to A2. By phylogenetic analysis, it was shown that all the 23 HBV/A1 isolates clustered together with isolates from Bangladesh, India, Japan, Nepal, the Philippines and United Arab Emirates, but not with those of Congo, Kenya, Malawi, Rwanda, South Africa, Tanzania, Uganda and Zimbabwe. Four amino acid residues in the polymerase (His138 in the terminal protein domain, Pro18 and His90 in the spacer, and Ser109 in the reverse transcriptase), and one (Phe17) in the precore region, predominated in Latin American and Asian HBV/A1 isolates, but were rarely encountered in African isolates, with the exception of those from Somalia. Specific variations of two adjacent amino acids in the C-terminal domain of the HBx protein, namely Ala146 and Pro147, were found in all the Brazilian, but rarely in the other HBV/A1 isolates. By Bayesian analysis, the existence of an 'Asian-American' clade within subgenotype A1 was supported by a posterior probability value of 0.996. The close relatedness of the Brazilian, Asian and Somalian isolates suggests that the HBV/A1 strains predominant in Brazil did not originate from the five million slaves who were imported from Central and Western Africa from 1551 to 1840, but rather from the 300-400,000 captives forcibly removed from southeast Africa at the middle of the 19th century.

  1. A Mathematical Model that Simulates Control Options for African Swine Fever Virus (ASFV)

    Science.gov (United States)

    Barongo, Mike B.; Bishop, Richard P; Fèvre, Eric M; Knobel, Darryn L; Ssematimba, Amos

    2016-01-01

    A stochastic model designed to simulate transmission dynamics of African swine fever virus (ASFV) in a free-ranging pig population under various intervention scenarios is presented. The model was used to assess the relative impact of the timing of the implementation of different control strategies on disease-related mortality. The implementation of biosecurity measures was simulated through incorporation of a decay function on the transmission rate. The model predicts that biosecurity measures implemented within 14 days of the onset of an epidemic can avert up to 74% of pig deaths due to ASF while hypothetical vaccines that confer 70% immunity when deployed prior to day 14 of the epidemic could avert 65% of pig deaths. When the two control measures are combined, the model predicts that 91% of the pigs that would have otherwise succumbed to the disease if no intervention was implemented would be saved. However, if the combined interventions are delayed (defined as implementation from > 60 days) only 30% of ASF-related deaths would be averted. In the absence of vaccines against ASF, we recommend early implementation of enhanced biosecurity measures. Active surveillance and use of pen-side diagnostic assays, preferably linked to rapid dissemination of this data to veterinary authorities through mobile phone technology platforms are essential for rapid detection and confirmation of ASF outbreaks. This prediction, although it may seem intuitive, rationally confirms the importance of early intervention in managing ASF epidemics. The modelling approach is particularly valuable in that it determines an optimal timing for implementation of interventions in controlling ASF outbreaks. PMID:27391689

  2. A Mathematical Model that Simulates Control Options for African Swine Fever Virus (ASFV.

    Directory of Open Access Journals (Sweden)

    Mike B Barongo

    Full Text Available A stochastic model designed to simulate transmission dynamics of African swine fever virus (ASFV in a free-ranging pig population under various intervention scenarios is presented. The model was used to assess the relative impact of the timing of the implementation of different control strategies on disease-related mortality. The implementation of biosecurity measures was simulated through incorporation of a decay function on the transmission rate. The model predicts that biosecurity measures implemented within 14 days of the onset of an epidemic can avert up to 74% of pig deaths due to ASF while hypothetical vaccines that confer 70% immunity when deployed prior to day 14 of the epidemic could avert 65% of pig deaths. When the two control measures are combined, the model predicts that 91% of the pigs that would have otherwise succumbed to the disease if no intervention was implemented would be saved. However, if the combined interventions are delayed (defined as implementation from > 60 days only 30% of ASF-related deaths would be averted. In the absence of vaccines against ASF, we recommend early implementation of enhanced biosecurity measures. Active surveillance and use of pen-side diagnostic assays, preferably linked to rapid dissemination of this data to veterinary authorities through mobile phone technology platforms are essential for rapid detection and confirmation of ASF outbreaks. This prediction, although it may seem intuitive, rationally confirms the importance of early intervention in managing ASF epidemics. The modelling approach is particularly valuable in that it determines an optimal timing for implementation of interventions in controlling ASF outbreaks.

  3. Assembly of replication-incompetent African horse sickness virus particles: rational design of vaccines for all serotypes.

    OpenAIRE

    Lulla, V.; Lulla, A; Wernike, K; Aebischer, A.; Beer, M.; Roy, P.

    2016-01-01

    UNLABELLED: African horse sickness virus (AHSV), an orbivirus in the Reoviridae family with nine different serotypes, causes devastating disease in equids. The virion particle is composed of seven proteins organized in three concentric layers, an outer layer made of VP2 and VP5, a middle layer made of VP7, and inner layer made of VP3 that encloses a replicase complex of VP1, VP4, and VP6 and a genome of 10 double-stranded RNA segments. In this study, we sought to develop highly efficacious ca...

  4. Innate and adaptive immune responses to in utero infection with bovine viral diarrhea virus

    Science.gov (United States)

    Infection of pregnant cows with noncytopathic (ncp) BVDV induces rapid innate and adaptive immune responses resulting in clearance of the virus in less than 3 weeks. Seven to 14 days after inoculation of the cow, ncpBVDV crosses the placenta and induces a fetal viremia. Establishment of persistent ...

  5. Quantifying the fitness advantage of polymerase substitutions in Influenza A/H7N9 viruses during adaptation to humans.

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    Judith M Fonville

    Full Text Available Adaptation of zoonotic influenza viruses towards efficient human-to-human transmissibility is a substantial public health concern. The recently emerged A/H7N9 influenza viruses in China provide an opportunity for quantitative studies of host-adaptation, as human-adaptive substitutions in the PB2 gene of the virus have been found in all sequenced human strains, while these substitutions have not been detected in any non-human A/H7N9 sequences. Given the currently available information, this observation suggests that the human-adaptive PB2 substitution might confer a fitness advantage to the virus in these human hosts that allows it to rise to proportions detectable by consensus sequencing over the course of a single human infection. We use a mathematical model of within-host virus evolution to estimate the fitness advantage required for a substitution to reach predominance in a single infection as a function of the duration of infection and the fraction of mutant present in the virus population that initially infects a human. The modeling results provide an estimate of the lower bound for the fitness advantage of this adaptive substitution in the currently sequenced A/H7N9 viruses. This framework can be more generally used to quantitatively estimate fitness advantages of adaptive substitutions based on the within-host prevalence of mutations. Such estimates are critical for models of cross-species transmission and host-adaptation of influenza virus infections.

  6. 42 CFR 71.56 - African rodents and other animals that may carry the monkeypox virus.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false African rodents and other animals that may carry... HUMAN SERVICES QUARANTINE, INSPECTION, LICENSING FOREIGN QUARANTINE Importations § 71.56 African rodents... import or attempt to import any rodents, whether dead or alive, that were obtained, directly...

  7. African swine fever virus infects macrophages, the natural host cells, via clathrin- and cholesterol-dependent endocytosis.

    Science.gov (United States)

    Galindo, Inmaculada; Cuesta-Geijo, Miguel Angel; Hlavova, Karolina; Muñoz-Moreno, Raquel; Barrado-Gil, Lucía; Dominguez, Javier; Alonso, Covadonga

    2015-03-16

    The main cellular target for African swine fever virus (ASFV) is the porcine macrophage. However, existing data about the early phases of infection were previously characterized in non-leukocyte cells such as Vero cells. Here, we report that ASFV enters the natural host cell using dynamin-dependent and clathrin-mediated endocytosis. This pathway is strongly pH-dependent during the first steps of infection in porcine macrophages. We investigated the effect of drugs inhibiting several endocytic pathways in macrophages and compared ASFV with vaccinia virus (VV), which apparently involves different entry pathways. The presence of cholesterol in cellular membranes was found to be essential for a productive ASFV infection while actin-dependent endocytosis and the participation of phosphoinositide-3-kinase (PI3K) activity were other cellular factors required in the process of viral entry. These findings improved our understanding of the ASFV interactions with macrophages that allow for successful viral replication.

  8. Protection of European domestic pigs from virulent African isolates of African swine fever virus by experimental immunisation.

    Science.gov (United States)

    King, Katherine; Chapman, Dave; Argilaguet, Jordi M; Fishbourne, Emma; Hutet, Evelyne; Cariolet, Roland; Hutchings, Geoff; Oura, Christopher A L; Netherton, Christopher L; Moffat, Katy; Taylor, Geraldine; Le Potier, Marie-Frederique; Dixon, Linda K; Takamatsu, Haru-H

    2011-06-20

    African swine fever (ASF) is an acute haemorrhagic disease of domestic pigs for which there is currently no vaccine. We showed that experimental immunisation of pigs with the non-virulent OURT88/3 genotype I isolate from Portugal followed by the closely related virulent OURT88/1 genotype I isolate could confer protection against challenge with virulent isolates from Africa including the genotype I Benin 97/1 isolate and genotype X Uganda 1965 isolate. This immunisation strategy protected most pigs challenged with either Benin or Uganda from both disease and viraemia. Cross-protection was correlated with the ability of different ASFV isolates to stimulate immune lymphocytes from the OURT88/3 and OURT88/1 immunised pigs.

  9. INNATE, ADAPTIVE AND INTRINSIC IMMUNITY IN HUMAN IMMUNODEFICIENCY VIRUS INFECTION

    Directory of Open Access Journals (Sweden)

    Suneth S. Perera

    2012-01-01

    Full Text Available The first line of defence of the innate immune system functions by recognizing highly conserved sets of molecular structures specific to the microbes, termed pathogen-associated molecular patterns, or PAMPs via the germ line-encoded receptors Pattern-Recognition Receptors (PRRs. In addition to the innate immune system, the vertebrates have also evolved a second line of defence termed adaptive immune system, which uses a diverse set of somatically rearranged receptors T-Cell Receptors (TCRs and B Cell Receptors (BCRs, which have the inherent ability to effectively recognise diverse antigens. The innate and adaptive immune systems are functionally tied in with the intrinsic immunity, which comprises of endogenous antiviral factors. Thus, this effective response to diverse microbial infections, including HIV, requires a coordinated interaction at several functional levels between innate, adaptive and intrinsic immune systems. This review provides a snapshot of roles played by the innate, adaptive and the intrinsic immune systems during HIV-infection, along with discussing recent developments highlighting the genomic basis of these responses and their regulation by micro-RNA (miRNAs.

  10. Complete Nucleotide Sequence of a South African Isolate of Grapevine Fanleaf Virus and Its Associated Satellite RNA

    Directory of Open Access Journals (Sweden)

    Johan T. Burger

    2013-07-01

    Full Text Available The complete sequences of RNA1, RNA2 and satellite RNA have been determined for a South African isolate of Grapevine fanleaf virus (GFLV-SACH44. The two RNAs of GFLV-SACH44 are 7,341 nucleotides (nt and 3,816 nt in length, respectively, and its satellite RNA (satRNA is 1,104 nt in length, all excluding the poly(A tail. Multiple sequence alignment of these sequences showed that GFLV-SACH44 RNA1 and RNA2 were the closest to the South African isolate, GFLV-SAPCS3 (98.2% and 98.6% nt identity, respectively, followed by the French isolate, GFLV-F13 (87.3% and 90.1% nt identity, respectively. Interestingly, the GFLV-SACH44 satRNA is more similar to three Arabis mosaic virus satRNAs (85%–87.4% nt identity than to the satRNA of GFLV-F13 (81.8% nt identity and was most distantly related to the satRNA of GFLV-R2 (71.0% nt identity. Full-length infectious clones of GFLV-SACH44 satRNA were constructed. The infectivity of the clones was tested with three nepovirus isolates, GFLV-NW, Arabis mosaic virus (ArMV-NW and GFLV-SAPCS3. The clones were mechanically inoculated in Chenopodium quinoa and were infectious when co-inoculated with the two GFLV helper viruses, but not when co-inoculated with ArMV-NW.

  11. Laboratory Investigations of African Pouched Rats (Cricetomys gambianus as a Potential Reservoir Host Species for Monkeypox Virus.

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    Christina L Hutson

    Full Text Available Monkeypox is a zoonotic disease endemic to central and western Africa, where it is a major public health concern. Although Monkeypox virus (MPXV and monkeypox disease in humans have been well characterized, little is known about its natural history, or its maintenance in animal populations of sylvatic reservoir(s. In 2003, several species of rodents imported from Ghana were involved in a monkeypox outbreak in the United States with individuals of three African rodent genera (Cricetomys, Graphiurus, Funisciurus shown to be infected with MPXV. Here, we examine the course of MPXV infection in Cricetomys gambianus (pouched Gambian rats and this rodent species' competence as a host for the virus. We obtained ten Gambian rats from an introduced colony in Grassy Key, Florida and infected eight of these via scarification with a challenge dose of 4X104 plaque forming units (pfu from either of the two primary clades of MPXV: Congo Basin (C-MPXV: n = 4 or West African (W-MPXV: n = 4; an additional 2 animals served as PBS controls. Viral shedding and the effect of infection on activity and physiological aspects of the animals were measured. MPXV challenged animals had significantly higher core body temperatures, reduced activity and increased weight loss than PBS controls. Viable virus was found in samples taken from animals in both experimental groups (C-MPXV and W-MPXV between 3 and 27 days post infection (p.i. (up to 1X108 pfu/ml, with viral DNA found until day 56 p.i. The results from this work show that Cricetomys gambianus (and by inference, probably the closely related species, Cricetomys emini can be infected with MPXV and shed viable virus particles; thus suggesting that these animals may be involved in the maintenance of MPXV in wildlife mammalian populations. More research is needed to elucidate the epidemiology of MPXV and the role of Gambian rats and other species.

  12. African swine fever outbreak on a medium-sized farm in Uganda: biosecurity breaches and within-farm virus contamination.

    Science.gov (United States)

    Chenais, Erika; Sternberg-Lewerin, Susanna; Boqvist, Sofia; Liu, Lihong; LeBlanc, Neil; Aliro, Tonny; Masembe, Charles; Ståhl, Karl

    2017-02-01

    In Uganda, a low-income country in east Africa, African swine fever (ASF) is endemic with yearly outbreaks. In the prevailing smallholder subsistence farming systems, farm biosecurity is largely non-existent. Outbreaks of ASF, particularly in smallholder farms, often go unreported, creating significant epidemiological knowledge gaps. The continuous circulation of ASF in smallholder settings also creates biosecurity challenges for larger farms. In this study, an on-going outbreak of ASF in an endemic area was investigated on farm level, including analyses of on-farm environmental virus contamination. The study was carried out on a medium-sized pig farm with 35 adult pigs and 103 piglets or growers at the onset of the outbreak. Within 3 months, all pigs had died or were slaughtered. The study included interviews with farm representatives as well as biological and environmental sampling. ASF was confirmed by the presence of ASF virus (ASFV) genomic material in biological (blood, serum) and environmental (soil, water, feed, manure) samples by real-time PCR. The ASFV-positive biological samples confirmed the clinical assessment and were consistent with known virus characteristics. Most environmental samples were found to be positive. Assessment of farm biosecurity, interviews, and the results from the biological and environmental samples revealed that breaches and non-compliance with biosecurity protocols most likely led to the introduction and within-farm spread of the virus. The information derived from this study provides valuable insight regarding the implementation of biosecurity measures, particularly in endemic areas.

  13. Pathogenesis of fulminant monkeypox with bacterial sepsis after experimental infection with West African monkeypox virus in a cynomolgus monkey.

    Science.gov (United States)

    Nagata, Noriyo; Saijo, Masayuki; Kataoka, Michiyo; Ami, Yasushi; Suzaki, Yuriko; Sato, Yuko; Iwata-Yoshikawa, Naoko; Ogata, Momoko; Kurane, Ichiro; Morikawa, Shigeru; Sata, Tetsutaro; Hasegawa, Hideki

    2014-01-01

    The pathogenesis of severe human monkeypox, which causes systemic and fulminant infections, is not clear. This study presents a case repot of fulminant monkeypox with bacterial sepsis after experimental infection with monkeypox virus in a cynomolgus monkey (Macaca fascicularis). In our previous study (Saijo et al., 2009, J Gen Virol), two cynomolgus monkeys became moribund after experimental infection with monkeypox virus Liberia strain, West African strain. One exhibited typical monkeypox-related papulovesicular lesions. The other monkey presented fulminant clinical symptoms with a characteristic flat red rash similar to that found in smallpox, which is associated with extremely high fatality rates. In this study, we found that the monkey with flat red rash had high levels of viremia and neutropenia, as well as high plasma levels of pro-inflammatory cytokines and chemokines compared with the other monkey. Monkeypox virus replicates in epithelial cells and macrophages in various organs. Sepsis due to Gram-positive cocci was confirmed histopathologically in the monkey with flat red rash. The lack of inflammatory response in the lesion suggested that the monkey with sepsis experienced strong immune suppression during the viral infection. The neutropenia and excessive inflammatory cytokine responses indicate that neutrophils play key roles in the pathogenesis of systemic and fulminant human monkeypox virus infections with sepsis.

  14. Remarkable sequence similarity between the dinoflagellate-infecting marine girus and the terrestrial pathogen African swine fever virus

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    Claverie Jean-Michel

    2009-10-01

    Full Text Available Abstract Heterocapsa circularisquama DNA virus (HcDNAV; previously designated as HcV is a giant virus (girus with a ~356-kbp double-stranded DNA (dsDNA genome. HcDNAV lytically infects the bivalve-killing marine dinoflagellate H. circularisquama, and currently represents the sole DNA virus isolated from dinoflagellates, one of the most abundant protists in marine ecosystems. Its morphological features, genome type, and host range previously suggested that HcDNAV might be a member of the family Phycodnaviridae of Nucleo-Cytoplasmic Large DNA Viruses (NCLDVs, though no supporting sequence data was available. NCLDVs currently include two families found in aquatic environments (Phycodnaviridae, Mimiviridae, one mostly infecting terrestrial animals (Poxviridae, another isolated from fish, amphibians and insects (Iridoviridae, and the last one (Asfarviridae exclusively represented by the animal pathogen African swine fever virus (ASFV, the agent of a fatal hemorrhagic disease in domestic swine. In this study, we determined the complete sequence of the type B DNA polymerase (PolB gene of HcDNAV. The viral PolB was transcribed at least from 6 h post inoculation (hpi, suggesting its crucial function for viral replication. Most unexpectedly, the HcDNAV PolB sequence was found to be closely related to the PolB sequence of ASFV. In addition, the amino acid sequence of HcDNAV PolB showed a rare amino acid substitution within a motif containing highly conserved motif: YSDTDS was found in HcDNAV PolB instead of YGDTDS in most dsDNA viruses. Together with the previous observation of ASFV-like sequences in the Sorcerer II Global Ocean Sampling metagenomic datasets, our results further reinforce the ideas that the terrestrial ASFV has its evolutionary origin in marine environments.

  15. Culicoides species abundance and potential over-wintering of African horse sickness virus in the Onderstepoort area, Gauteng, South Africa

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    Gert J. Venter

    2014-02-01

    Full Text Available In South Africa, outbreaks of African horse sickness (AHS occur in summer; no cases are reported in winter, from July to September. The AHS virus (AHSV is transmitted almost exclusively by Culicoides midges (Diptera: Ceratopogonidae, of which Culicoides imicola is considered to be the most important vector. The over-wintering mechanism of AHSV is unknown. In this study, more than 500 000 Culicoides midges belonging to at least 26 species were collected in 88 light traps at weekly intervals between July 2010 and September 2011 near horses in the Onderstepoort area of South Africa. The dominant species was C. imicola. Despite relatively low temperatures and frost, at least 17 species, including C. imicola, were collected throughout winter (June–August. Although the mean number of midges per night fell from > 50 000 (March to < 100 (July and August, no midge-free periods were found. This study, using virus isolation on cell cultures and a reverse transcriptase polymerase chain reaction (RT-PCR assay, confirmed low infection prevalence in field midges and that the detection of virus correlated to high numbers. Although no virus was detected during this winter period, continuous adult activity indicated that transmission can potentially occur. The absence of AHSV in the midges during winter can be ascribed to the relatively low numbers collected coupled to low infection prevalence, low virus replication rates and low virus titres in the potentially infected midges. Cases of AHS in susceptible animals are likely to start as soon as Culicoides populations reach a critical level.

  16. The 2014 Ebola virus outbreak in West Africa highlights no evidence of rapid evolution or adaptation to humans

    Science.gov (United States)

    Li, Xingguang; Zai, Junjie; Liu, Haizhou; Feng, Yi; Li, Fan; Wei, Jing; Zou, Sen; Yuan, Zhiming; Shao, Yiming

    2016-01-01

    Following its immergence in December 2013, the recent Zaire Ebola virus (EBOV) outbreak in West Africa has spread and persisted for more than two years, making it the largest EBOV epidemic in both scale and geographical region to date. In this study, a total of 726 glycoprotein (GP) gene sequences of the EBOV full-length genome obtained from West Africa from the 2014 outbreak, combined with 30 from earlier outbreaks between 1976 and 2008 were used to investigate the genetic divergence, evolutionary history, population dynamics, and selection pressure of EBOV among distinct epidemic waves. Results from our dataset showed that no non-synonymous substitutions occurred on the GP gene coding sequences of EBOV that were likely to have affected protein structure or function in any way. Furthermore, the significantly different dN/dS ratios observed between the 2014 West African outbreak and earlier outbreaks were more likely due to the confounding presence of segregating polymorphisms. Our results highlight no robust evidence that the 2014 EBOV outbreak is fast-evolving and adapting to humans. Therefore, the unprecedented nature of the 2014 EBOV outbreak might be more likely related to non-virological elements, such as environmental and sociological factors. PMID:27767073

  17. Molecular characterization of African swine fever virus isolates originating from outbreaks in the Russian Federation between 2007 and 2011.

    Science.gov (United States)

    Malogolovkin, Alexander; Yelsukova, Alexandra; Gallardo, Carmina; Tsybanov, Sodnom; Kolbasov, Denis

    2012-08-17

    African swine fever is one of the most important viral diseases of pigs and which caused significant economic damage on the pig production worldwide. Nowadays, it is still present on the African continent, in Transcaucasus countries (TCC), on Island of Sardinia and in Russia. Outbreaks of the disease have been reported in Russia for the last four years, affected especially the Southern Federal District of the country. Since 2010, a new outbreak area has been observed in the Northwestern Federal District. In order to study the evolution of African swine fever virus (ASFV) isolates, strains were collected in the Russian Federation from 2007 to 2011 and investigated by means of partial sequencing and fragment length polymorphism. In detail, 7 variable regions, namely B646L, E183L, I196L, B602L, I73R/I329R, I78R/I215L and KP86R were investigated. Phylogenetic analyses revealed 100% nucleotide identity of B646L and E183L gene sequences of all examined isolates. All isolates formed one genetic cluster within genotype II. Moreover, no amplified fragment length polymorphism (AFLP) was observed for B602L, I196L, I73R/I329R, and I78R/I215L genes. The flanking primers used to amplify the KP86R gene failed to amplify a product in all the isolates. The obtained data strongly suggests that only one ASFV virus variant caused the outbreaks from 2007 to 2011 in the territory of the Russian Federation.

  18. Phylogeographic reconstruction of African yellow fever virus isolates indicates recent simultaneous dispersal into east and west Africa.

    Directory of Open Access Journals (Sweden)

    Andrew Beck

    Full Text Available Yellow fever virus (YFV is a mosquito-borne flavivirus that is a major public health problem in tropical areas of Africa and South America. There have been detailed studies on YFV ecology in West Africa and South America, but current understanding of YFV circulation on the African continent is incomplete. This inadequacy is especially notable for East and Central Africa, for which the unpredictability of human outbreaks is compounded by limitations in both historical and present surveillance efforts. Sparse availability of nucleotide sequence data makes it difficult to investigate the dispersal of YFV in these regions of the continent. To remedy this, we constructed Bayesian phylogenetic and geographic analyses utilizing 49 partial genomic sequences to infer the structure of YFV divergence across the known range of the virus on the African continent. Relaxed clock analysis demonstrated evidence for simultaneous divergence of YFV into east and west lineages, a finding that differs from previous hypotheses of YFV dispersal from reservoirs located on edges of the endemic range. Using discrete and continuous geographic diffusion models, we provide detailed structure of YFV lineage diversity. Significant transition links between extant East and West African lineages are presented, implying connection between areas of known sylvatic cycling. The results of demographic modeling reinforce the existence of a stably maintained population of YFV with spillover events into human populations occurring periodically. Geographically distinct foci of circulation are reconstructed, which have significant implications for studies of YFV ecology and emergence of human disease. We propose further incorporation of Bayesian phylogeography into formal GIS analyses to augment studies of arboviral disease.

  19. Symmetry Breaking and Adaptation Evidence from a Toy Model of a Virus

    CERN Document Server

    Mora, J; Waelbroeck, H

    1997-01-01

    We argue that the phenomenon of symmetry breaking in genetics can enhance the adaptability of a species to changes in the environment. In the case of a virus, the claim is that the codon bias in the neutralization epitope improves the virus' ability to generate mutants that evade the induced immune response. We support our claim with a simple ``toy model'' of a viral epitope evolving in competition with the immune system. The effective selective advantage of a higher mutability leads to a dominance of codons that favour non-synonymous mutations. The results in this paper suggest the possibility of emergence of an algorithmic language in more complicated systems.

  20. Episodic adaptive diversification of classical swine fever virus RNA-dependent RNA polymerase NS5B.

    Science.gov (United States)

    Li, Yan; Yang, Zexiao

    2015-12-01

    Classical swine fever virus (CSFV) is the pathogen that causes a highly infectious disease of pigs and has led to disastrous losses to pig farms and related industries. The RNA-dependent RNA polymerase (RdRp) NS5B is a central component of the replicase complex (RC) in some single-stranded RNA viruses, including CSFV. On the basis of genetic variation, the CSFV RdRps could be clearly divided into 2 major groups and a minor group, which is consistent with the phylogenetic relationships and virulence diversification of the CSFV isolates. However, the adaptive signature underlying such an evolutionary profile of the polymerase and the virus is still an interesting open question. We analyzed the evolutionary trajectory of the CSFV RdRps over different timescales to evaluate the potential adaptation. We found that adaptive selection has driven the diversification of the RdRps between, but not within, CSFV major groups. Further, the major adaptive divergence-related sites are located in the surfaces relevant to the interaction with other component(s) of RC and the entrance and exit of the template-binding channel. These results might shed some light on the nature of the RdRp in virulence diversification of CSFV groups.

  1. Molecular characterisation of African swine fever viruses from Nigeria (2003-2006) recovers multiple virus variants and reaffirms CVR epidemiological utility.

    Science.gov (United States)

    Owolodun, Olajide A; Bastos, Armanda D S; Antiabong, John F; Ogedengbe, Mosunmola E; Ekong, Pius S; Yakubu, Bitrus

    2010-12-01

    Samples collected from wild and domestic suids in Nigeria, over a 3-year period (2003-2006), were evaluated for African swine fever (ASF) virus genome presence by targeting three discrete genome regions, namely the 478-bp C-terminal p72 gene region advocated for genotype assignment, a 780-bp region spanning the 5'-ends of the pB125R and pB646L (p72) genes and the hypervariable central variable region (CVR) encoded within the 9RL ORF (pB602L). ASF virus (ASFV) presence was confirmed in 23 of the 26 wild and domestic pigs evaluated. No evidence of ASF infection was found in two warthogs from Adamawa State; however, one bushpig from Plateau State was positive. Nucleotide sequences of the 478-bp and 780-bp amplicons were identical across all ASFV-positive samples sequenced. However, five discrete CVR variants were recovered, bringing the total number identified to date, from Nigeria, to six. The largest of the CVR variants, termed 'Tet-36' was identical to a virus causing outbreaks in neighbouring Benin in 1997, indicating a prolonged persistence of this virus type in Nigeria. Co-circulation of three tetramer types (Tet-36, Tet-27 and Tet-20) was found in Plateau State in July 2004, whilst in Benue State, two tetramer types (Tet-20 and Tet-21) were present in August 2005. Despite simultaneous field presence, individual co-infection was not observed. This study has reaffirmed the epidemiological utility of the CVR genome region for distinguishing between geographically and temporally constrained genotype I viruses, and has revealed the presence of multiple ASFV variants in Nigeria.

  2. Adaptation to abiotic conditions drives local adaptation in bacteria and viruses coevolving in heterogeneous environments.

    Science.gov (United States)

    Gorter, Florien A; Scanlan, Pauline D; Buckling, Angus

    2016-02-01

    Parasite local adaptation, the greater performance of parasites on their local compared with foreign hosts, has important consequences for the maintenance of diversity and epidemiology. While the abiotic environment may significantly affect local adaptation, most studies to date have failed either to incorporate the effects of the abiotic environment, or to separate them from those of the biotic environment. Here, we tease apart biotic and abiotic components of local adaptation using the bacterium Pseudomonas fluorescens and its viral parasite bacteriophage Φ2. We coevolved replicate populations of bacteria and phages at three different temperatures, and determined their performance against coevolutionary partners from the same and different temperatures. Crucially, we measured performance at different assay temperatures, which allowed us to disentangle adaptation to biotic and abiotic habitat components. Our results show that bacteria and phages are more resistant and infectious, respectively, at the temperature at which they previously coevolved, confirming that local adaptation to abiotic conditions can play a crucial role in determining parasite infectivity and host resistance. Our work underlines the need to assess host-parasite interactions across multiple relevant abiotic environments, and suggests that microbial adaption to local temperatures can create ecological barriers to dispersal across temperature gradients.

  3. Neurovirulence comparison of chikungunya virus isolates of the Asian and East/Central/South African genotypes from Malaysia.

    Science.gov (United States)

    Chiam, Chun Wei; Chan, Yoke Fun; Ong, Kien Chai; Wong, Kum Thong; Sam, I-Ching

    2015-11-01

    Chikungunya virus (CHIKV), an alphavirus of the family Togaviridae, causes fever, polyarthritis and rash. There are three genotypes: West African, Asian and East/Central/South African (ECSA). The latter two genotypes have caused global outbreaks in recent years. Recent ECSA CHIKV outbreaks have been associated with severe neurological disease, but it is not known if different CHIKV genotypes are associated with different neurovirulence. In this study, the neurovirulence of Asian (MY/06/37348) and ECSA (MY/08/065) strains of CHIKV isolated in Malaysia were compared. Intracerebral inoculation of either virus into suckling mice was followed by virus titration, histopathology and gene expression analysis of the harvested brains. Both strains of CHIKV replicated similarly, yet mice infected with MY/06/37348 showed higher mortality. Histopathology findings showed that both CHIKV strains spread within the brain (where CHIKV antigen was localized to astrocytes and neurons) and beyond to skeletal muscle. In MY/06/37348-infected mice, apoptosis, which is associated with neurovirulence in alphaviruses, was observed earlier in brains. Comparison of gene expression showed that a pro-apoptotic gene (eIF2αK2) was upregulated at higher levels in MY/06/37348-infected mice, while genes involved in anti-apoptosis (BIRC3), antiviral responses and central nervous system protection (including CD40, IL-10RA, MyD88 and PYCARD) were upregulated more highly in MY/08/065-infected mice. In conclusion, the higher mortality observed following MY/06/37348 infection in mice is due not to higher viral replication in the brain, but to differentially expressed genes involved in host immune responses. These findings may help to identify therapeutic strategies and biomarkers for neurological CHIKV infections.

  4. Genomic Signatures for Avian H7N9 Viruses Adapting to Humans.

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    Guang-Wu Chen

    Full Text Available An avian influenza A H7N9 virus emerged in March 2013 and caused a remarkable number of human fatalities. Genome variability in these viruses may provide insights into host adaptability. We scanned over 140 genomes of the H7N9 viruses isolated from humans and identified 104 positions that exhibited seven or more amino acid substitutions. Approximately half of these substitutions were identified in the influenza ribonucleoprotein (RNP complex. Although PB2 627K of the avian virus promotes replication in humans, 45 of the 147 investigated PB2 sequences retained the E signature at this position, which is an avian characteristic. We discovered 10 PB2 substitutions that covaried with K627E. An RNP activity assay showed that Q591K, D701N, and M535L restored the polymerase activity in human cells when 627K transformed to an avian-like E. Genomic analysis of the human-isolated avian influenza virus is crucial in assessing genome variability, because relationships between position-specific variations can be observed and explored. In this study, we observed alternative positions that can potentially compensate for PB2 627K, a well-known marker for cross-species infection. An RNP assay suggested Q591K, D701N, and M535L as potential markers for an H7N9 virus capable of infecting humans.

  5. The pathogenesis of highly virulent African Swine Fever virus in domestic pigs exposed via intraoropharyngeal, intranasopharyngeal, and intramuscular inoculation, and by direct contact with infected pigs

    Science.gov (United States)

    In order to optimize novel systems for African Swine Fever Virus (ASFV) vaccine development, domestic pigs were challenged with the highly virulent ASFV-Malawi strain via intraoropharyngeal (IOP), intranasopharyngeal (INP), intramuscular (IM), and direct contact (DC) routes. Direct challenge doses ...

  6. The Ep152R ORF of African Swine Fever Virus strain Georgia encodes for an essential gene that interacts with host protein BAG6

    Science.gov (United States)

    African swine fever virus (ASFV) is the etiological agent of a contagious and often lethal disease of domestic pigs that has significant economic consequences for the swine industry. The viral genome encodes for more than 150 genes, and only a select few have been studied in some detail. Here we rep...

  7. STSV2 as a Model Crenarchaeal Virus for Studying Virus-Host Interactions and CRISPR-Cas Adaptive Immunity

    DEFF Research Database (Denmark)

    León Sobrino, Carlos

    , the archaea harbour their own viruses, which constitute an extraordinarily diverse group with exotic morphologies and unique features. Prokaryotes possess a variety of defence mechanisms. The CRISPR-Cas adaptive immune system is of great importance for archaea –84% of them possess it, compared to 45...... generate immune memory by inserting in its own genome short invader-derived DNA fragments forming a database –the CRISPR locus. Little was known about this system until recent years, and the generation of immune memory has been the most elusive step. In this work, the interactions of the spindle......-shaped monocaudavirus STSV2 and its host Sulfolobus islandicus REY15A were studied. This interaction produced, after several days, de novo CRISPR adaptation – that is, without any previous memory that can act as a trigger. We employed transcriptome sequencing to characterise the long-term progression...

  8. Single strain isolation method for cell culture-adapted hepatitis C virus by end-point dilution and infection.

    Directory of Open Access Journals (Sweden)

    Nao Sugiyama

    Full Text Available The hepatitis C virus (HCV culture system has enabled us to clarify the HCV life cycle and essential host factors for propagation. However, the virus production level of wild-type JFH-1 (JFH-1/wt is limited, and this leads to difficulties in performing experiments that require higher viral concentrations. As the cell culture-adapted JFH-1 has been reported to have robust virus production, some mutations in the viral genome may play a role in the efficiency of virus production. In this study, we obtained cell culture-adapted virus by passage of full-length JFH-1 RNA-transfected Huh-7.5.1 cells. The obtained virus produced 3 log-fold more progeny viruses as compared with JFH-1/wt. Several mutations were identified as being responsible for robust virus production, but, on reverse-genetics analysis, the production levels of JFH-1 with these mutations did not reach the level of cell culture-adapted virus. By using the single strain isolation method by end-point dilution and infection, we isolated two strains with additional mutations, and found that these strains have the ability to produce more progeny viruses. On reverse-genetics analysis, the strains with these additional mutations were able to produce robust progeny viruses at comparable levels as cell culture-adapted JFH-1 virus. The strategy used in this study will be useful for identifying strains with unique characteristics, such as robust virus production, from a diverse population, and for determining the responsible mutations for these characteristics.

  9. Molecular evolution of Azagny virus, a newfound hantavirus harbored by the West African pygmy shrew (Crocidura obscurior in Côte d'Ivoire

    Directory of Open Access Journals (Sweden)

    Kang Hae Ji

    2011-07-01

    Full Text Available Abstract Background Tanganya virus (TGNV, the only shrew-associated hantavirus reported to date from sub-Saharan Africa, is harbored by the Therese's shrew (Crocidura theresae, and is phylogenetically distinct from Thottapalayam virus (TPMV in the Asian house shrew (Suncus murinus and Imjin virus (MJNV in the Ussuri white-toothed shrew (Crocidura lasiura. The existence of myriad soricid-borne hantaviruses in Eurasia and North America would predict the presence of additional hantaviruses in sub-Saharan Africa, where multiple shrew lineages have evolved and diversified. Methods Lung tissues, collected in RNAlater®, from 39 Buettikofer's shrews (Crocidura buettikoferi, 5 Jouvenet's shrews (Crocidura jouvenetae, 9 West African pygmy shrews (Crocidura obscurior and 21 African giant shrews (Crocidura olivieri captured in Côte d'Ivoire during 2009, were systematically examined for hantavirus RNA by RT-PCR. Results A genetically distinct hantavirus, designated Azagny virus (AZGV, was detected in the West African pygmy shrew. Phylogenetic analysis of the S, M and L segments, using maximum-likelihood and Bayesian methods, under the GTR+I+Γ model of evolution, showed that AZGV shared a common ancestry with TGNV and was more closely related to hantaviruses harbored by soricine shrews than to TPMV and MJNV. That is, AZGV in the West African pygmy shrew, like TGNV in the Therese's shrew, did not form a monophyletic group with TPMV and MJNV, which were deeply divergent and basal to other rodent- and soricomorph-borne hantaviruses. Ancestral distributions of each hantavirus lineage, reconstructed using Mesquite 2.74, suggested that the common ancestor of all hantaviruses was most likely of Eurasian, not African, origin. Conclusions Genome-wide analysis of many more hantaviruses from sub-Saharan Africa are required to better understand how the biogeographic origin and radiation of African shrews might have contributed to, or have resulted from, the evolution

  10. Sensitivity of African swine fever virus to type I interferon is linked to genes within multigene families 360 and 505

    Science.gov (United States)

    Golding, Josephine P.; Goatley, Lynnette; Goodbourn, Steve; Dixon, Linda K.; Taylor, Geraldine; Netherton, Christopher L.

    2016-01-01

    African swine fever virus (ASFV) causes a lethal haemorrhagic disease of pigs. There are conflicting reports on the role of interferon in ASFV infection. We therefore analysed the interaction of ASFV with porcine interferon, in vivo and in vitro. Virulent ASFV induced biologically active IFN in the circulation of pigs from day 3-post infection, whereas low virulent OUR T88/3, which lacks genes from multigene family (MGF) 360 and MGF505, did not. Infection of porcine leucocytes enriched for dendritic cells, with ASFV, in vitro, induced high levels of interferon, suggesting a potential source of interferon in animals undergoing acute ASF. Replication of OUR T88/3, but not virulent viruses, was reduced in interferon pretreated macrophages and a recombinant virus lacking similar genes to those absent in OUR T88/3 was also inhibited. These findings suggest that as well as inhibiting the induction of interferon, MGF360 and MGF505 genes also enable ASFV to overcome the antiviral state. PMID:27043071

  11. Advantages of a single-cycle production assay to study cell culture-adaptive mutations of hepatitis C virus

    DEFF Research Database (Denmark)

    Russell, Rodney S; Meunier, Jean-Christophe; Takikawa, Shingo

    2008-01-01

    mutations that were selected during serial passage in Huh-7.5 cells were studied. Recombinant genomes containing all five mutations produced 3-4 logs more infectious virions than did wild type. Neither a coding mutation in NS5A nor a silent mutation in E2 was adaptive, whereas coding mutations in E2, p7......The JFH1 strain of hepatitis C virus (HCV) is unique among HCV isolates, in that the wild-type virus can traverse the entire replication cycle in cultured cells. However, without adaptive mutations, only low levels of infectious virus are produced. In the present study, the effects of five......, and NS2 all increased virus production. A single-cycle replication assay in CD81-deficient cells was developed to study more precisely the effect of the adaptive mutations. The E2 mutation had minimal effect on the amount of infectious virus released but probably enhanced entry into cells. In contrast...

  12. How Can African Agriculture Adapt to Climate Change? A Counterfactual Analysis from Ethiopia

    OpenAIRE

    2012-01-01

    We analyze the impact of different adaptation strategies on crop net revenues in the Nile Basin of Ethiopia. We estimate a multinomial endogenous switching regression model of climate change adaptation and crop net revenues and implement a counterfactual analysis. Households data are combined with spatial climate data. We find that adaptation to climate change based upon a portfolio of strategies significantly increases farm net revenues. Changing crop varieties has a positive and significant...

  13. Adaptation and growth kinetics study of an Indian isolate of virulent duck enteritis virus in Vero cells.

    Science.gov (United States)

    Aravind, S; Kamble, Nitin M; Gaikwad, Satish S; Shukla, Sanjeev Kumar; Dey, Sohini; Mohan, C Madhan

    2015-01-01

    Duck virus enteritis, also known as duck plague, is a viral infection of ducks caused by duck enteritis virus (DEV). The control of the disease is mainly done by vaccination with chicken embryo adapted live virus that is known to be poorly immunogenic and elicits only partial protection. Further, the embryo propagated vaccine virus pose a threat of harboring other infectious agents. Seeing these limitations, the present study reports for the first time regarding propagation and adaptation of a virulent Indian isolate of duck enteritis virus in Vero cell line. In this study isolation of an outbreak virus from Kerala state was done in chicken embryo fibroblast cell culture (CEF). Then adapted the DEV isolate in the Vero cell line. The characteristic cytopathic effects (CPE) of clumping and fusion of Vero cells were observed starting from the 7th passage onwards. The presence of the virus and its multiplication in Vero cells was confirmed by detection of viral specific DNA and antigen by using polymerase chain reaction (PCR) and indirect immuno fluorescent assay (IIFA), respectively. PCR detection of DEV using self designed primers for US4 (gD) and UL30 (DNA Polymerase) gene has been reported for the in the present study. The kinetics of DEV in Vero cells revealed a maximum infectivity titer of 10(5.6) TCID 50/ml after 48hr of viral infection. Compared to chicken embryo adapted DVE vaccine virus, the Vero cell culture system is free from other infectious agents. So it will be a good candidate for cultivation and propagation of duck enteritis virus vaccine strain. Further research studies are suggested to explore the feasibility of utilizing this Vero cell culture adapted DEV isolate for developing an attenuated vaccine virus against duck virus enteritis.

  14. Mokola virus infection : description of recent South African cases and a review of the virus epidemiology : case report

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    B.F. Von Teichman

    1998-07-01

    Full Text Available Five cases of Mokola virus, a lyssavirus related to rabies, are described. The cases occurred in cats from the East London, Pinetown and Pietermaritzburg areas of South Africa from February 1996 to February 1998. Each of the cats was suspected of being rabid and their brains were submitted for laboratory confirmation. Four of the cases were positive, but with atypical fluorescence, and 1 was negative. Mokola virus infection was identified by anti-lyssavirus nucleocapsid monoclonal antibody typing. As in rabies cases, the predominant clinical signs were of unusual behaviour. Aggression was present, but only during handling. Four of the 5 cats had been vaccinated for rabies, which is consistent with other studies that show that rabies vaccination does not appear to protect against Mokola virus. Since Mokola may be confused with rabies, the incidence of Mokola virus may be more common in Africa than is currently reported. As human infections may be fatal, the emergence of this virus is a potential threat to public health.

  15. Current situation, genetic relationship and control measures of infectious bronchitis virus variants circulating in African regions

    Directory of Open Access Journals (Sweden)

    Khadija Khataby

    2016-08-01

    Three S1 gene hypervariable regions were studied and compared to the reference genotypes/serotypes that found emerging in African regions. This comparison was based on phylogenetic trees, nucleotide and amino-acid sequence analysis. It clearly appears that IBV variants reported in Africa, display a low genetic relationship between them and with the majority of the reference strains emerging in neighboring countries, except the case of variants from Libya and Egypt that show a high relatedness. Also the Massachusetts serotypes were the most prevalent co-circulating with both serotypes, Italy02 type in Morocco and Qx-like genotype in South part of the African continent. In order to control the IBV variants in African regions, an efficient vaccination strategy program should be implemented.

  16. Frequent substitution polymorphisms in African green monkey CCR5 cluster at critical sites for infections by simian immunodeficiency virus SIVagm, implying ancient virus-host coevolution.

    Science.gov (United States)

    Kuhmann, S E; Madani, N; Diop, O M; Platt, E J; Morvan, J; Müller-Trutwin, M C; Barré-Sinoussi, F; Kabat, D

    2001-09-01

    In contrast to humans, several primate species are believed to have harbored simian immunodeficiency viruses (SIVs) since ancient times. In particular, the geographically dispersed species of African green monkeys (AGMs) are all infected with highly diversified SIVagm viruses at high prevalences (greater than 50% of sexually mature individuals) without evident diseases, implying that the progenitor monkeys were infected prior to their dispersal. If this is correct, AGMs would be expected to have accumulated frequent resistance-conferring polymorphisms in host genes that are important for SIV replication. Accordingly, we analyzed the coding sequences of the CCR5 coreceptors from 26 AGMs (52 alleles) in distinct populations of the four species. These samples contained 29 nonsynonymous coding changes and only 15 synonymous nucleotide substitutions, implying intense functional selection. Moreover, 24 of the resulting amino acid substitutions were tightly clustered in the CCR5 amino terminus (D13N in the vervets and Y14N in the tantalus species) or in the first extracellular loop (Q93R and Q93K in all species). The Y14N substitution was extremely frequent in the 12 wild-born African tantalus, with 7 monkeys being homozygous for this substitution and 4 being heterozygous. Although two of these heterozygotes and the only wild-type homozygote were naturally infected with SIVagm, none of the Y14N homozygotes were naturally infected. A focal infectivity assay for SIVagm indicated that all five tested SIVagms efficiently use CCR5 as a coreceptor and that they also use CXCR6 (STRL33/Bonzo) and GPR15 (BOB) with lower efficiencies but not CXCR4. Interestingly, the D13N, Y14N, Q93R, and Q93K substitutions in AGM CCR5 all strongly inhibited infections by the SIVagm isolates in vitro. The Y14N substitution eliminates a tyrosine sulfation site that is important for infections and results in partial N-linked glycosylation (i.e., 60% efficiency) at this position. Nevertheless, the CCR

  17. Generation and characterization of a cold-adapted attenuated live H3N2 subtype influenza virus vaccine candidate

    Institute of Scientific and Technical Information of China (English)

    AN Wen-qi; LIU Xiu-fan; WANG Xi-liang; YANG Peng-hui; DUAN Yue-qiang; LUO De-yan; TANG Chong; JIA Wei-hong; XING Li; SHI Xin-fu; ZHANG Yu-jing

    2009-01-01

    Background H3N2 subtype influenza A viruses have been identified in humans worldwide, raising concerns about their pandemic potential and prompting the development of candidate vaccines to protect humans against this subtype of influenza A virus. The aim of this study was to establish a system for rescuing of a cold-adapted high-yielding H3N2 subtype human influenza virus by reverse genetics. Methods In order to generate better and safer vaccine candidate viruses, a cold-adapted high yielding reassortant H3N2 influenza A virus was genetically constructed by reverse genetics and was designated as rgAA-H3N2. The rgAA-H3N2 virus contained HA and NA genes from an epidemic strain A/Wisconsin/67/2005 (H3N2) in a background of internal genes derived from the master donor viruses (MDV), cold-adapted (ca), temperature sensitive (te), live attenuated influenza virus strain A/Ann Arbor/6/60 (MDV-A). Results In this presentation, the virus HA titer of rgAA-H3N2 in the allantoic fluid from infected embryonated eggs was as high as 1:1024. A fluorescent focus assay (FFU) was performed 24-36 hours post-infection using a specific antibody and bright staining was used for determining the virus titer. The allantoic fluid containing the recovered influenza virus was analyzed in a hemagglutination inhibition (HI) test and the specific inhibition was found. Conclusion The results mentioned above demonstrated that cold-adapted, attenuated reassortant H3N2 subtype influenza A virus was successfully generated, which laid a good foundation for the further related research.

  18. Evaluation of the Effectiveness and Implementation of an Adapted Evidence-Based Mammography Intervention for African American Women

    Directory of Open Access Journals (Sweden)

    Linda Highfield

    2015-01-01

    Full Text Available Breast cancer mortality disparities continue, particularly for uninsured and minority women. A number of effective evidence-based interventions (EBIs exist for addressing barriers to mammography screening; however, their uptake and use in community has been limited. Few cancer-specific studies have evaluated adapted EBIs in new contexts, and fewer still have considered implementation. This study sought to (1 evaluate the effectiveness of an adapted mammography EBI in improving appointment keeping in African American women and (2 describe processes of implementation in a new practice setting. We used the type 1 hybrid design to test effectiveness and implementation using a quasi-experimental design. Logistic regression and intent-to-treat analysis were used to evaluate mammography appointment attendance. The no-show rate was 44% (comparison versus 19% (intervention. The adjusted odds of a woman in the intervention group attending her appointment were 3.88 p<0.001. The adjusted odds of a woman attending her appointment in the intent-to-treat analysis were 2.31 p<0.05. Adapted EBI effectiveness was 3.88 (adjusted OR versus 2.10 (OR for the original program, indicating enhanced program effect. A number of implementation barriers and facilitators were identified. Our findings support previous studies noting that sequentially measuring EBI efficacy and effectiveness, followed by implementation, may be missing important contextual information.

  19. Cell culture adaptation mutations in foot-and-mouth disease virus serotype A capsid proteins: implications for receptor interactions

    Science.gov (United States)

    In this study we describe the adaptive changes fixed on the capsid of several foot-and-mouth disease virus serotype A strains during propagation in cell monolayers. Viruses passaged extensively in three cell lines (BHK-21, LFBK and IB-RS-2), consistently gained several positively charged amino acids...

  20. African Swine Fever Virus Georgia isolate harboring deletions of 9GL and MGF360/505 genes in highly attenuated in swine but does not confer protection against parental virus challenge

    Science.gov (United States)

    African swine fever virus (ASFV) produces a contagious disease of domestic pigs that results in severe economic consequences to the swine industry. Control of the disease has been hampered by the unavailability of vaccines. We recently reported the development of two experimental vaccine strains (...

  1. Institutional perceptions, adaptive capacity and climate change response in a post-conflict country: a case study from Central African Republic

    NARCIS (Netherlands)

    Brown, H.C.P.; Smit, B.; Somorin, O.A.; Sonwa, D.J.; Ngana, F.

    2013-01-01

    The Central African Republic (CAR) faces increased vulnerability to climate change because it is a low-income country with low adaptive capacity; a situation that is exacerbated by recent civil conflict. This research analysed the perceptions of decision-makers within, and the response of diverse na

  2. Evidence of local adaptation in plant virus effects on host-vector interactions.

    Science.gov (United States)

    Mauck, K E; De Moraes, C M; Mescher, M C

    2014-07-01

    host and apparently maladaptive with respect to virus transmission (e.g., host plant quality for aphids was significantly improved in this instance, and aphid dispersal was reduced). Taken together, these findings provide evidence of adaption by CMV to local hosts (including reduced infectivity and replication in novel versus native hosts) and further suggest that such adaptation may extend to effects on host-plant traits mediating interactions with aphid vectors. Thus, these results are consistent with the hypothesis that virus effects on host-vector interactions can be adaptive, and they suggest that multi-host pathogens may exhibit adaptation with respect to these and other effects on host phenotypes, perhaps especially in homogeneous monocultures.

  3. Experimental pig-to-pig transmission dynamics for African swine fever virus, Georgia 2007/1 strain.

    Science.gov (United States)

    Guinat, C; Gubbins, S; Vergne, T; Gonzales, J L; Dixon, L; Pfeiffer, D U

    2016-01-01

    African swine fever virus (ASFV) continues to cause outbreaks in domestic pigs and wild boar in Eastern European countries. To gain insights into its transmission dynamics, we estimated the pig-to-pig basic reproduction number (R 0) for the Georgia 2007/1 ASFV strain using a stochastic susceptible-exposed-infectious-recovered (SEIR) model with parameters estimated from transmission experiments. Models showed that R 0 is 2·8 [95% confidence interval (CI) 1·3-4·8] within a pen and 1·4 (95% CI 0·6-2·4) between pens. The results furthermore suggest that ASFV genome detection in oronasal samples is an effective diagnostic tool for early detection of infection. This study provides quantitative information on transmission parameters for ASFV in domestic pigs, which are required to more effectively assess the potential impact of strategies for the control of between-farm epidemic spread in European countries.

  4. Current status of African swine fever virus in a population of wild boar in eastern Poland (2014-2015).

    Science.gov (United States)

    Woźniakowski, Grzegorz; Kozak, Edyta; Kowalczyk, Andrzej; Łyjak, Magdalena; Pomorska-Mól, Małgorzata; Niemczuk, Krzysztof; Pejsak, Zygmunt

    2016-01-01

    African swine fever virus (ASFV) was detected in wild boar in eastern Poland in early 2014. So far, 65 cases of ASFV infection in wild boar have been recognised. The methods used for ASFV detection included highly specific real-time PCR with a universal probe library (UPL), enzyme-linked immunosorbent assay (ELISA), and an immunoperoxidase test (IPT) for identification of anti-ASFV antibodies. The positive ASF cases were located near the border with Belarus in Sokółka and Białystok counties. Some of the countermeasures for disease prevention include early ASF diagnosis by ASFV DNA identification as well as detection of specific antibodies by systematic screening. The aim of this study was to assess the current ASF status in a Polish population of wild boar during the last two years (2014-2015).

  5. [Continuous cell subline A4C2/9K and its application to the african swine fever virus study].

    Science.gov (United States)

    Balysheva, V I; Prudnikova, E Yu; Galnbek, T V; Balyshev, V M

    2015-01-01

    A new continuous cell subline A4C2/9K highly sensitive to the african swine fever virus (ASFV) was prepared. All the tested ASFV strains isolated in the Russian Federation in 2008-2013 proliferated in this cell culture exhibiting hemadsorption and accumulated at a titer of up to 6.5 Ig HAU50/cm3. The cell culture A4C2/9K can be used for ASFV isolation or determination of its infectious activity and serotype identity. The culture versions of the ASFV strain Stavropol 01/08 at passages 24 and 33 in the cell culture A4C2/9K lost their pathogenicity for pigs.

  6. Rift Valley fever virus infection in African Buffalo (Syncerus caffer) herds in rural South Africa: Evidence of interepidemic transmission

    Science.gov (United States)

    LaBeaud, A.D.; Cross, P.C.; Getz, W.M.; Glinka, A.; King, C.H.

    2011-01-01

    Rift Valley fever virus (RVFV) is an emerging biodefense pathogen that poses significant threats to human and livestock health. To date, the interepidemic reservoirs of RVFV are not well defined. In a longitudinal survey of infectious diseases among African buffalo during 2000-2006, 550 buffalo were tested for antibodies against RVFV in 820 capture events in 302 georeferenced locations in Kruger National Park, South Africa. Overall, 115 buffalo (21%) were seropositive. Seroprevalence of RVFV was highest (32%) in the first study year, and decreased progressively in subsequent years, but had no detectable impact on survival. Nine (7%) of 126 resampled, initially seronegative animals seroconverted during periods outside any reported regional RVFV outbreaks. Seroconversions for RVFV were detected in significant temporal clusters during 2001-2003 and in 2004. These findings highlight the potential importance of wildlife as reservoirs for RVFV and interepidemic RVFV transmission in perpetuating regional RVFV transmission risk. Copyright ?? 2011 by The American Society of Tropical Medicine and Hygiene.

  7. An outbreak of encephalomyocarditis-virus infection in free-ranging African elephants in the Kruger National Park.

    Science.gov (United States)

    Grobler, D G; Raath, J P; Braack, L E; Keet, D F; Gerdes, G H; Barnard, B J; Kriek, N P; Jardine, J; Swanepoel, R

    1995-06-01

    A cluster of four deaths in late December 1993, marked the onset of an outbreak of disease of African elephants (Loxodonta africana) in the Kruger National Park (KNP) in South Africa, which has an estimated population of 7,500 elephants. Mortalities peaked in January 1994, with 32 deaths, and then declined steadily to reach pre-outbreak levels by September, but sporadic losses continued until November. During the outbreak altogether 64 elephants died, of which 53 (83%) were adult bulls. Archival records revealed that, in addition to the usual losses from known causes such as poaching and intraspecific fighting, sporadic deaths from unexplained causes had, in fact, occurred in widely scattered locations from at least 1987 onwards, and from that time until the perceived outbreak of disease there had been 48 such deaths involving 33 (69%) adult bulls. Carcases had frequently become decomposed or had been scavenged by the time they were found, but seven of eight elephants examined early in 1994 had lesions of cardiac failure suggestive of encephalomyocarditis (EMC)-virus infection, and the virus was isolated from the heart muscles of three fresh carcases. The results of tests for neutralizing antibody on 362 elephant sera collected for unrelated purposes from 1984 onwards and kept frozen, indicated that the virus had been present in the KNP since at least 1987. Antibody prevalences of 62 of 116 (53%) 18 of 139 (13%) and seven of 33 (21%) were found in elephants in three different regions of the KNP in 1993 and 1994. Studies had been conducted on myomorph rodents in the KNP for unrelated purposes since 1984, and trapping attempts were increased during the perceived outbreak of disease in elephants. There was a striking temporal correlation between the occurrence of a population explosion (as evidenced by markedly increased catch rates per trap-night) and a surge in prevalence of antibody to EM virus in rodents, and the occurrence of the outbreak of disease in elephants.

  8. Adaptations to soil drying in woody seedlings of African locust bean, (Parkia biglobosa (Jacq.) Benth.).

    Science.gov (United States)

    Osonubi, O; Fasehun, F E

    1987-12-01

    Stomatal conductance, transpiration and xylem pressure potential of African locust bean (Parkia biglobosa (Jacq.) Benth.) seedlings subjected from the sixth week after emergence to four weeks of continuous soil drought did not differ from those of well-watered, control plants until two-thirds of the available soil water had been used. In both well-watered and drought-treated plants, stomatal conductance was highest early in the day when vapor pressure deficits were low, but decreased sharply by midday when evaporative demand reached its highest value. There was no increase in stomatal conductance later in the day as vapor pressure deficit declined. The relationship between transpiration rate and xylem pressure potential showed non-linearity and hysteresis in both control and drought-treated plants, which seems to indicate that the plants had a substantial capacity to store water. The rate of leaf extension in African locust bean seedlings subjected to six consecutive 2-week cycles of soil drought declined relative to that of well-watered, control plants, whereas relative root extension increased. It appears that African locust bean seedlings minimized the impact of drought by: (1) restricting transpiration to the early part of the day when a high ratio of carbon gain to water loss can be achieved; (2) utilizing internally stored water during periods of rapid transpiration; (3) reducing the rate of leaf expansion and final leaf size in response to soil drought without reducing the rate of root extension, thereby reducing the ratio of transpiring leaf surface area to absorbing root surface area.

  9. 非洲猪瘟病毒研究进展%Research on African swine fever Virus

    Institute of Scientific and Technical Information of China (English)

    孙怀昌

    2006-01-01

    非洲猪瘟(African swine fever,ASF)是由非洲猪瘟病毒(African swine fever virus,ASFV)引起的猪的一种烈性传染病,曾在非洲和欧洲国家广泛流行,并造成巨大的经济损失。虽然本病目前仅在部分非洲国家呈地方性流行,但由于对养猪业的危害巨大,且无有效的疫苗用于防疫,仍被国际兽疫局列为A类重点防范的传染病。对于ASFV而言,虽是严格的动物病毒,所致疾病的危害也限于非洲部分地区,但由于具有一些独特的特点,尤其是具有复杂的免疫逃逸机制,一直是动物分子病毒学研究的热点,而且取得了突破性研究进展。

  10. Small-scale pig farmers' behavior, silent release of African swine fever virus and consequences for disease spread.

    Science.gov (United States)

    Costard, Solenne; Zagmutt, Francisco J; Porphyre, Thibaud; Pfeiffer, Dirk Udo

    2015-11-27

    The expanding distribution of African swine fever (ASF) is threatening the pig industry worldwide. Most outbreaks occur in backyard and small-scale herds, where poor farmers often attempt to limit the disease's economic consequences by the emergency sale of their pigs. The risk of African swine fever virus (ASFV) release via this emergency sale was investigated. Simulation modeling was used to study ASFV transmission in backyard and small-scale farms as well as the emergency sale of pigs, and the potential impact of improving farmers and traders' clinical diagnosis ability-its timeliness and/or accuracy-was assessed. The risk of ASFV release was shown to be high, and improving farmers' clinical diagnosis ability does not appear sufficient to effectively reduce this risk. Estimates obtained also showed that the distribution of herd size within the backyard and small-scale sectors influences the relative contribution of these farms to the risk of release of infected pigs. These findings can inform surveillance and control programs.

  11. Detection of African swine fever virus from formalin fixed and non-fixed tissues by polymerase chain reaction

    Directory of Open Access Journals (Sweden)

    P. D. Luka

    2014-10-01

    Full Text Available Aim: Formalin fixing and paraffin embedding of tissue samples is one of the techniques for preserving the structural integrity of cells for a very long time. However, extraction and analysis of genomic material from formalin fixed tissue (FFT remains a challenge despite numerous attempts to develop a more effective method. The success of polymerase chain reaction (PCR depends on the quality of DNA extract. Materials and Methods: Here we assessed the conventional method of DNA extraction from FFT for African swine fever virus (ASFV detection. The modified conventional method gave a higher quality DNA when compared with commercially available DNA extraction kits (QIAamp® DNA Mini Kit, DNeasy® Blood and Tissue Kit, and ZR Genomic DNA™ Tissue MiniPrep. Results: An average A260/A280 DNA purity of 0.86-1.68 and 3.22-5.32 μg DNA/mg for formalin fixed and non-fixed tissues, respectively using a conventional method. In a reproducible and three times repeat PCR, the ASFV DNA expected product size of 278 bp was obtained from the DNA extract of the conventional method but not from the DNA extract of the commercial kits. Conclusion: The present study has demonstrated that the conventional method extracts ASFV genome better than commercial kit. In summary, the commercial kit extraction appeared not suitable to purify ASFV DNA from FFT. We, therefore, recommend that the use of the conventional method be considered for African swine fever DNA extraction from FFT.

  12. Serological survey of bovine viral diarrhoea virus in Namibian and South African kudu (Tragelaphus strepsiceros and eland (Taurotragus oryx

    Directory of Open Access Journals (Sweden)

    Terence P. Scott

    2013-02-01

    Full Text Available Bovine viral diarrhoea virus (BVDV is a pestivirus that affects members of the order Artiodactyla, including members of the subfamily Bovinae. Little is known about the seroprevalence of BVDV in southern Africa, especially the prevalence in wild ruminant populations such as kudu (Tragelaphus strepsiceros. A handful of random surveys suggested that seroprevalence ranged between 6% and 70% in southern African wild ruminants. The present study aimed to determine the seroprevalence of BVDV amongst kudu and eland (Taurotragus oryx from Namibia and South Africa. A BVDV-specific enzyme-linked immunosorbent assay was performed on 50 serum samples from kudu and eland from South Africa and Namibia. The seroprevalence of BVDV in South African kudu was 71%, identical to that in Namibian kudu. The seroprevalence in Namibian eland was 40%. The kudu and cattle farming (free ranging regions in Namibia predominantly overlap in the central regions, ensuring ample opportunity for cross-species transmission of BVDV. It is therefore important to determine the true prevalence of BVDV in southern Africa in both domesticated and wild animals. In addition, a potential link between BVDV incidence and a devastating rabies epidemic in Namibian kudu was proposed and such a notion could be supported or discredited by comparative prevalence data.

  13. Molecular characterization of African swine fever virus from domestic pigs in northern Tanzania during an outbreak in 2013.

    Science.gov (United States)

    Misinzo, Gerald; Kwavi, David E; Sikombe, Christopher D; Makange, Mariam; Peter, Emma; Muhairwa, Amandus P; Madege, Michael J

    2014-10-01

    African swine fever (ASF) is an acute, highly contagious and deadly viral hemorrhagic fever of domestic pigs caused by African swine fever virus (ASFV), a double-stranded DNA virus of the family Asfarviridae. In this study, molecular diagnosis and characterization of outbreak ASFV in northern Tanzania, was performed on spleen, lymph node, kidney, and heart samples collected in June and July 2013 from domestic pigs that died during a hemorrhagic disease outbreak. Confirmatory diagnosis of ASF was performed using polymerase chain reaction (PCR) by partial amplification of B646L gene of ASFV encoding the major capsid protein p72 using PPA1/PPA2 primers. PCR using PPA1/PPA2 primers produced an expected PCR product size, confirming ASF outbreak in northern Tanzania. In addition, nucleotide amplification and sequencing, and phylogenetic reconstruction of the variable 3'-end of the B646L gene and complete E183L gene encoding the inner envelope transmembrane protein p54 showed that the 2013 outbreak ASFV from northern Tanzania were 100 % identical and clustered into ASFV B646L (p72) and E183L (p54) genotype X. Furthermore, the tetrameric amino acid repeats within the central variable region (CVR) of the B602L gene coding for the J9L protein had the signature BNBA(BN)5NA with a single novel tetramer NVDI (repeat code N). The results of the present study confirm an ASF outbreak in northern Tanzania in the year 2013 and show that the present outbreak ASFV is closely related to other ASFV from ticks, warthogs, and domestic pigs previously reported from Tanzania.

  14. Experimental clinical and pathologic characterization of West African Newcastle disease viruses

    Science.gov (United States)

    Newcastle disease is a very significant disease of commercial and backyard poultry in Africa, and has been reported in numerous African countries. Recent analysis of strains from West Africa has revealed the emergence of at least one novel genetic lineage that differs from the previously-characteriz...

  15. Characterization of African swine fever virus Caucasus isolate in European wild boars.

    Science.gov (United States)

    Gabriel, Claudia; Blome, Sandra; Malogolovkin, Alexander; Parilov, Stanislav; Kolbasov, Denis; Teifke, Jens P; Beer, Martin

    2011-12-01

    Since 2007, African swine fever has spread from the Caucasus region. To learn more about the dynamics of the disease in wild boars (Sus scrofa), we conducted experiments by using European wild boars. We found high virulence of Caucasus isolates limited potential for establishment of endemicity.

  16. Cross-cultural adaptation and validation of the South African Pain Catastrophizing Scale (SA-PCS among patients with fibromyalgia

    Directory of Open Access Journals (Sweden)

    Morris Linzette D

    2012-11-01

    Full Text Available Abstract Background Pain catastrophization has recently been recognized as a barrier to the healthy development of physical functioning among chronic pain patients. Levels of pain catastrophization in chronic pain patients are commonly measured using the Pain Catastrophizing Scale (PCS. Objective To cross-culturally adapt and validate the South African PCS (SA-PCS among English-, Afrikaans- and Xhosa-speaking patients with fibromyalgia living in the Cape Metropole area, Western Cape, South Africa. Methods The original PCS was cross-culturally adapted in accordance with international standards to develop an English, Afrikaans and Xhosa version of the SA-PCS using a repeated measures study design. Psychometric testing included face/content validity, internal consistency (Cronbach’s alpha-α, test-retest reliability (intraclass coefficient correlations-ICC, sensitivity-to-change and cross-sectional convergent validity (by comparing the adapted SA-PCS to related constructs. Results The cross-culturally adapted English, Afrikaans and Xhosa SA-PCS showed good face and content validity, excellent internal consistency (with Chronbach’s α = 0.98, 0.98 and 0.97 for the English, Afrikaans and Xhosa SA-PCS, as a whole, respectively, excellent test-retest reliability (with ICC’s of 0.90, 0.91 and 0.89 for the English, Afrikaans and Xhosa SA-PCS, respectively; as well as satisfactory sensitivity-to-change (with a minimum detectable change of 8.8, 9.0 and 9.3 for the English, Afrikaans and Xhosa SA-PCS, respectively and cross-sectional convergent validity (when compared to pain severity as well as South African versions of the Tampa scale for Kinesiophobia and the revised Fibromyalgia Impact Questionnaire. Conclusion The SA-PCS can therefore be recommended as simple, efficient, valid and reliable tool which shows satisfactory sensitivity-to-change and cross-sectional convergent validity, for use among English, Afrikaans and Xhosa-speaking patients with

  17. Adapting an Evidence-Based HIV Intervention for At-Risk African American College Women at Historically Black Colleges and Universities Who Use Alcohol and Drugs

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    Kyla Marie Sawyer-Kurian

    2012-11-01

    Full Text Available The convergence of the high prevalence of HIV incidence among African American adolescent and adult women along with substance use and risky sexual behavior among university students necessitates the development of a HIV intervention specifically addressing culture, gender, and college factors for female African American university students. The woman-focused HIV intervention was chosen for adaptation because it has been shown to be efficacious with reducing risk for African American women who use alcohol and drugs, and has been successfully adapted 7 times. The target population was African American college women enrolled at a historically Black university who use alcohol and other drugs, and who engaged in risky sex behaviors. To understand and assess the needs of this population, we conducted four focus groups with African American college women, two in-depth interviews with faculty, and a combination of in-depth interviews and focus groups with student affairs and health staff that were analyzed using content analysis. From this analysis, several themes emerged that were used to adapt the intervention. Emerging themes included challenges related to identity and societal stereotypes, lack of knowledge about sexual health (i.e., negotiating safer sex and the function of female and male anatomies, high incidents of pregnancy, negative consequences related to alcohol and marijuana use, and the need to incorporate testimonies from college students, media enhancements, and role-plays to convey intervention messages. After the preliminary adaptation, 11 college women reviewed the adapted intervention and provided positive feedback. Plans for future research are discussed.

  18. Capsid proteins from field strains of foot-and-mouth disease virus confer a pathogenic phenotype in cattle on an attenuated, cell-culture-adapted virus

    DEFF Research Database (Denmark)

    Bøtner, Anette; Kakker, Naresh K.; Barbezange, Cyril

    2011-01-01

    Chimeric foot-and-mouth disease viruses (FMDVs) have been generated from plasmids containing full-length FMDV cDNAs and characterized. The parental virus cDNA was derived from the cell-culture-adapted O1Kaufbeuren B64 (O1K B64) strain. Chimeric viruses, containing capsid coding sequences derived...... cells than the rescued parental O1K B64 virus. The two chimeric viruses displayed the expected antigenicity in serotype-specific antigen ELISAs. Following inoculation of each virus into cattle, the rescued O1K B64 strain proved to be attenuated whereas, with each chimeric virus, typical clinical signs...... from the O/UKG/34/2001 or A/Turkey 2/2006 field viruses, were constructed using the backbone from the O1K B64 cDNA, and viable viruses (O1K/O-UKG and O1K/A-Tur, respectively) were successfully rescued in each case. These viruses grew well in primary bovine thyroid cells but grew less efficiently in BHK...

  19. Novel Polymerase Gene Mutations for Human Adaptation in Clinical Isolates of Avian H5N1 Influenza Viruses.

    Science.gov (United States)

    Arai, Yasuha; Kawashita, Norihito; Daidoji, Tomo; Ibrahim, Madiha S; El-Gendy, Emad M; Takagi, Tatsuya; Takahashi, Kazuo; Suzuki, Yasuo; Ikuta, Kazuyoshi; Nakaya, Takaaki; Shioda, Tatsuo; Watanabe, Yohei

    2016-04-01

    A major determinant in the change of the avian influenza virus host range to humans is the E627K substitution in the PB2 polymerase protein. However, the polymerase activity of avian influenza viruses with a single PB2-E627K mutation is still lower than that of seasonal human influenza viruses, implying that avian viruses require polymerase mutations in addition to PB2-627K for human adaptation. Here, we used a database search of H5N1 clade 2.2.1 virus sequences with the PB2-627K mutation to identify other polymerase adaptation mutations that have been selected in infected patients. Several of the mutations identified acted cooperatively with PB2-627K to increase viral growth in human airway epithelial cells and mouse lungs. These mutations were in multiple domains of the polymerase complex other than the PB2-627 domain, highlighting a complicated avian-to-human adaptation pathway of avian influenza viruses. Thus, H5N1 viruses could rapidly acquire multiple polymerase mutations that function cooperatively with PB2-627K in infected patients for optimal human adaptation.

  20. Shedding dynamics of Morogoro virus, an African arenavirus closely related to Lassa virus, in its natural reservoir host Mastomys natalensis.

    Science.gov (United States)

    Borremans, Benny; Vossen, Raphaël; Becker-Ziaja, Beate; Gryseels, Sophie; Hughes, Nelika; Van Gestel, Mats; Van Houtte, Natalie; Günther, Stephan; Leirs, Herwig

    2015-05-29

    Arenaviruses can cause mild to severe hemorrhagic fevers. Humans mainly get infected through contact with infected rodents or their excretions, yet little is known about transmission dynamics within rodent populations. Morogoro virus (MORV) is an Old World arenavirus closely related to Lassa virus with which it shares the same host species Mastomys natalensis. We injected MORV in its host, and sampled blood and excretions at frequent intervals. Infection in adults was acute; viral RNA disappeared from blood after 18 days post infection (dpi) and from excretions after 39 dpi. Antibodies were present from 7 dpi and never disappeared. Neonatally infected animals acquired a chronic infection with RNA and antibodies in blood for at least 3 months. The quantified excretion and antibody patterns can be used to inform mathematical transmission models, and are essential for understanding and controlling transmission in the natural rodent host populations.

  1. Dendritic Cells in Innate and Adaptive Immune Responses against Influenza Virus

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    Artur Summerfield

    2009-11-01

    Full Text Available Dendritic cells (DC are major players in both innate and adaptive immune responses against influenza virus. These immune responses, as well as the important interface between the innate and adaptive systems, are orchestrated by specialized subsets of DC, including conventional steady-state DC, migratory DC and plasmacytoid DC. The characteristics and efficacy of the responses are dependent on the relative activity of these DC subsets, rendering DC crucial for the development of both naïve and memory immune responses. However, due to their critical role, DC also contribute to the immunopathological processes observed during acute influenza, such as that caused by the pathogenic H5N1 viruses. Therein, the role of different DC subsets in the induction of interferon type I, proinflammatory cytokine and chemokine responses is important for the outcome of interaction between the virus and host immune defences. The present review will present current knowledge on this area, relating to the importance of DC activity for the induction of efficacious humoral and cell-mediated immune responses. This will include the main viral elements associated with the triggering or inhibition of DC activation. Finally, the current knowledge on understanding how differences in various vaccines influence the manner of immune defence induction will be presented.

  2. Propagation of human hepatitis A virus in African green monkey kidney cell culture: primary isolation and serial passage.

    Science.gov (United States)

    Daemer, R J; Feinstone, S M; Gust, I D; Purcell, R H

    1981-04-01

    Human hepatitis A virus (HAV) was propagated in primary African Green Monkey (Cercopithecus aethiops) kidney (AGMK) cell cultures. Three strains of HAV were used: MS-1, SD-11, and HM-175. Cells were inoculated with marmoset-passaged material or human clinical specimens and were stained by direct immunofluorescence to establish the identity of the virus. Both clinical samples and marmoset-passaged material produced immunofluorescence. HAV antigen was found scattered throughout the cytoplasm of inoculated cultures. The HM-175 strain produced the most intense immunofluorescence. This strain of HAV had been serially passaged in cell culture seven times. Blocking experiments with paired human sera from naturally acquired HAV infections and hyperimmune chimpanzee serum from an experimentally infected animal established that the immunofluorescence was specific. The viral antigen was found to be exclusively intracellular. The interval to maximum HAV antigen expression was decreased by serial passage. The HAV strain described herein, which was recovered directly from the stool specimen of a patient with HAV in primary AGMK cell culture, may prove useful as a source of antigen for serological tests and as a candidate vaccine strain.

  3. Validation of a French adaptation of the Harvard Trauma Questionnaire among torture survivors from sub-Saharan African countries

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    Capucine de Fouchier

    2012-12-01

    Full Text Available Background: To date no validated instrument in the French language exists to screen for posttraumatic stress disorder (PTSD in survivors of torture and organized violence. Objective: The aim of this study is to adapt and validate the Harvard Trauma Questionnaire (HTQ to this population. Method: The adapted version was administered to 52 French-speaking torture survivors, originally from sub-Saharan African countries, receiving psychological treatment in specialized treatment centers. A structured clinical interview for DSM was also conducted in order to assess if they met criteria for PTSD. Results: Cronbach's alpha coefficient for the HTQ Part 4 was adequate (0.95. Criterion validity was evaluated using receiver operating characteristic curve analysis that generated good classification accuracy for PTSD (0.83. At the original cut-off score of 2.5, the HTQ demonstrated high sensitivity and specificity (0.87 and 0.73, respectively. Conclusion: Results support the reliability and validity of the French version of the HTQ.

  4. Evaluating Responses in Complex Adaptive Systems: Insights on Water Management from the Southern African Millennium Ecosystem Assessment (SAfMA

    Directory of Open Access Journals (Sweden)

    Erin Bohensky

    2005-06-01

    Full Text Available Ecosystem services are embedded in complex adaptive systems. These systems are riddled with nonlinearities, uncertainties, and surprises, and are made increasingly complex by the many human responses to problems or changes arising within them. In this paper we attempt to determine whether there are certain factors that characterize effective responses in complex systems. We construct a framework for response evaluation with three interconnected scopes or spatial and temporal domains: the scope of an impact, the scope of the awareness of the impact, and the scope of the power or influence to respond. Drawing from the experience of the Southern African Millennium Ecosystem Assessment (SAfMA, we explore the applicability of this framework to the example of water management in southern Africa, where an ongoing paradigm shift in some areas has enabled a transition from supply-side to demand-side responses and the creation of new institutions to manage water across scales. We suggest that the most effective responses exhibit congruence between the impact, awareness, and power scopes; distribute impacts across space and time; expand response options; enhance social memory; and depend on power-distributing mechanisms. We conclude by stressing the need for sufficient flexibility to adapt responses to the specific, ever-evolving contexts in which they are implemented. Although our discussion focuses on water in southern Africa, we believe that the framework has broad applicability to a range of complex systems and places.

  5. Exploring sexual practices of South African soldiers to determine vulnerability to the Human Immune Deficiency Virus.

    OpenAIRE

    2006-01-01

    Although HIV occurs in all social groups in South African society, certain populations are more vulnerable to HIV through risky behaviour patterns. Of relevance to the present study, are the high risk situations that deployed soldiers are exposed to. Three issues indicated the necessity for a study of this kind to be conducted; (a) the statistics pointing to a higher incidence of HIV infections among military personnel than among the general population, (b) military personnel’s unique vulnera...

  6. Assessment of the pathogenicity of cell-culture-adapted Newcastle disease virus strain Komarov

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    Sivam Visnuvinayagam

    2015-09-01

    Full Text Available Newcastle disease vaccines hitherto in vogue are produced from embryonated chicken eggs. Egg-adapted mesogenic vaccines possess several drawbacks such as paralysis and mortality in 2-week-old chicks and reduced egg production in the egg-laying flock. Owing to these possible drawbacks, we attempted to reduce the vaccine virulence for safe vaccination by adapting the virus in a chicken embryo fibroblast cell culture (CEFCC system. Eighteen passages were carried out by CEFCC, and the pathogenicity was assessed on the basis of the mean death time, intracerebral pathogenicity index, and intravenous pathogenicity index, at equal passage intervals. Although the reduction in virulence demonstrated with increasing passage levels in CEFCC was encouraging, 20% of the 2-week-old birds showed paralytic symptoms with the virus vaccine from the 18th(final passage. Thus, a tissue-culture-adapted vaccine would demand a few more passages by CEFCC in order to achieve a complete reduction in virulence for use as a safe and effective vaccine, especially among younger chicks. Moreover, it can be safely administered even to unprimed 8-week-old birds.

  7. Assessment of the pathogenicity of cell-culture-adapted Newcastle disease virus strain Komarov.

    Science.gov (United States)

    Visnuvinayagam, Sivam; Thangavel, K; Lalitha, N; Malmarugan, S; Sukumar, Kuppannan

    2015-01-01

    Newcastle disease vaccines hitherto in vogue are produced from embryonated chicken eggs. Egg-adapted mesogenic vaccines possess several drawbacks such as paralysis and mortality in 2-week-old chicks and reduced egg production in the egg-laying flock. Owing to these possible drawbacks, we attempted to reduce the vaccine virulence for safe vaccination by adapting the virus in a chicken embryo fibroblast cell culture (CEFCC) system. Eighteen passages were carried out by CEFCC, and the pathogenicity was assessed on the basis of the mean death time, intracerebral pathogenicity index, and intravenous pathogenicity index, at equal passage intervals. Although the reduction in virulence demonstrated with increasing passage levels in CEFCC was encouraging, 20% of the 2-week-old birds showed paralytic symptoms with the virus vaccine from the 18(th)(final) passage. Thus, a tissue-culture-adapted vaccine would demand a few more passages by CEFCC in order to achieve a complete reduction in virulence for use as a safe and effective vaccine, especially among younger chicks. Moreover, it can be safely administered even to unprimed 8-week-old birds.

  8. Induction of antibody responses to African horse sickness virus (AHSV in ponies after vaccination with recombinant modified vaccinia Ankara (MVA.

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    Rachael Chiam

    Full Text Available BACKGROUND: African horse sickness virus (AHSV causes a non-contagious, infectious disease in equids, with mortality rates that can exceed 90% in susceptible horse populations. AHSV vaccines play a crucial role in the control of the disease; however, there are concerns over the use of polyvalent live attenuated vaccines particularly in areas where AHSV is not endemic. Therefore, it is important to consider alternative approaches for AHSV vaccine development. We have carried out a pilot study to investigate the ability of recombinant modified vaccinia Ankara (MVA vaccines expressing VP2, VP7 or NS3 genes of AHSV to stimulate immune responses against AHSV antigens in the horse. METHODOLOGY/PRINCIPAL FINDINGS: VP2, VP7 and NS3 genes from AHSV-4/Madrid87 were cloned into the vaccinia transfer vector pSC11 and recombinant MVA viruses generated. Antigen expression or transcription of the AHSV genes from cells infected with the recombinant viruses was confirmed. Pairs of ponies were vaccinated with MVAVP2, MVAVP7 or MVANS3 and both MVA vector and AHSV antigen-specific antibody responses were analysed. Vaccination with MVAVP2 induced a strong AHSV neutralising antibody response (VN titre up to a value of 2. MVAVP7 also induced AHSV antigen-specific responses, detected by western blotting. NS3 specific antibody responses were not detected. CONCLUSIONS: This pilot study demonstrates the immunogenicity of recombinant MVA vectored AHSV vaccines, in particular MVAVP2, and indicates that further work to investigate whether these vaccines would confer protection from lethal AHSV challenge in the horse is justifiable.

  9. Estimating the Basic Reproductive Number (R0 for African Swine Fever Virus (ASFV Transmission between Pig Herds in Uganda.

    Directory of Open Access Journals (Sweden)

    Mike B Barongo

    Full Text Available African swine fever (ASF is a highly contagious, lethal and economically devastating haemorrhagic disease of domestic pigs. Insights into the dynamics and scale of virus transmission can be obtained from estimates of the basic reproduction number (R0. We estimate R0 for ASF virus in small holder, free-range pig production system in Gulu, Uganda. The estimation was based on data collected from outbreaks that affected 43 villages (out of the 289 villages with an overall pig population of 26,570 between April 2010 and November 2011. A total of 211 outbreaks met the criteria for inclusion in the study. Three methods were used, specifically; (i GIS- based identification of the nearest infectious neighbour based on the Euclidean distance between outbreaks, (ii epidemic doubling time, and (iii a compartmental susceptible-infectious (SI model. For implementation of the SI model, three approaches were used namely; curve fitting (CF, a linear regression model (LRM and the SI/N proportion. The R0 estimates from the nearest infectious neighbour and epidemic doubling time methods were 3.24 and 1.63 respectively. Estimates from the SI-based method were 1.58 for the CF approach, 1.90 for the LRM, and 1.77 for the SI/N proportion. Since all these values were above one, they predict the observed persistence of the virus in the population. We hypothesize that the observed variation in the estimates is a consequence of the data used. Higher resolution and temporally better defined data would likely reduce this variation. This is the first estimate of R0 for ASFV in a free range smallholder pig keeping system in sub-Saharan Africa and highlights the requirement for more efficient application of available disease control measures.

  10. Estimating the Basic Reproductive Number (R0) for African Swine Fever Virus (ASFV) Transmission between Pig Herds in Uganda.

    Science.gov (United States)

    Barongo, Mike B; Ståhl, Karl; Bett, Bernard; Bishop, Richard P; Fèvre, Eric M; Aliro, Tony; Okoth, Edward; Masembe, Charles; Knobel, Darryn; Ssematimba, Amos

    2015-01-01

    African swine fever (ASF) is a highly contagious, lethal and economically devastating haemorrhagic disease of domestic pigs. Insights into the dynamics and scale of virus transmission can be obtained from estimates of the basic reproduction number (R0). We estimate R0 for ASF virus in small holder, free-range pig production system in Gulu, Uganda. The estimation was based on data collected from outbreaks that affected 43 villages (out of the 289 villages with an overall pig population of 26,570) between April 2010 and November 2011. A total of 211 outbreaks met the criteria for inclusion in the study. Three methods were used, specifically; (i) GIS- based identification of the nearest infectious neighbour based on the Euclidean distance between outbreaks, (ii) epidemic doubling time, and (iii) a compartmental susceptible-infectious (SI) model. For implementation of the SI model, three approaches were used namely; curve fitting (CF), a linear regression model (LRM) and the SI/N proportion. The R0 estimates from the nearest infectious neighbour and epidemic doubling time methods were 3.24 and 1.63 respectively. Estimates from the SI-based method were 1.58 for the CF approach, 1.90 for the LRM, and 1.77 for the SI/N proportion. Since all these values were above one, they predict the observed persistence of the virus in the population. We hypothesize that the observed variation in the estimates is a consequence of the data used. Higher resolution and temporally better defined data would likely reduce this variation. This is the first estimate of R0 for ASFV in a free range smallholder pig keeping system in sub-Saharan Africa and highlights the requirement for more efficient application of available disease control measures.

  11. Genetic characterisation of African swine fever viruses from recent and historical outbreaks in Sardinia (1978-2009).

    Science.gov (United States)

    Giammarioli, Monica; Gallardo, Carmina; Oggiano, Annalisa; Iscaro, Carmen; Nieto, Raquel; Pellegrini, Claudia; Dei Giudici, Silvia; Arias, Marisa; De Mia, Gian Mario

    2011-06-01

    Three discrete regions of the African swine fever virus (ASFV) were analysed in the genomes of a wide range of isolates collected from wild and domestic pigs in Sardinia, over a 31-year period (1978-2009). The analysis was conducted by genotyping based on sequence data from three single copy ASF genes. The E183L gene encoding the structural protein p54 and part of the gene encoding the p72 protein were used to delineate genotypes, before intra-genotypic resolution of viral relationships by analysis of tetramer amino acid repeats within the hypervariable central variable region (CVR) of the B602L gene. The data revealed that these isolates did not show significant variation in their p72 and p54 sequence when compared between different isolates showing a remarkable genetic stability of these genome regions. In particular, the phylogeny revealed that all the Sardinian isolates belong to the same largest and most homogeneous p72 genotype I together with viruses from Europe, South America, the Caribbean and West Africa, and p54 genotype Ia which comprises viruses from Europe and America. The analysis of B602L gene revealed a minor difference in the number of tetramer repeats, placing the Sardinian isolates into two clusters, accordingly to their temporal distribution, namely sub-group III and sub-group X, this latter showing a deletion of 12 tetramer repeats located in the centre of the array. The genetic variation of this fragment suggests that one sub-group could be derived from the other supporting the hypothesis of a single introduction of ASFV in Sardinia.

  12. Adaptation of the African couples HIV testing and counseling model for men who have sex with men in the United States: an application of the ADAPT-ITT framework.

    Science.gov (United States)

    Sullivan, Patrick S; Stephenson, Rob; Grazter, Beau; Wingood, Gina; Diclemente, Ralph; Allen, Susan; Hoff, Colleen; Salazar, Laura; Scales, Lamont; Montgomery, Jeanne; Schwartz, Ann; Barnes, Jasper; Grabbe, Kristina

    2014-01-01

    To respond to the need for new HIV prevention services for men who have sex with men (MSM) in the United States, and to respond to new data on the key role of main partnerships in US MSM epidemics, we sought to develop a new service for joint HIV testing of male couples. We used the ADAPT-ITT framework to guide our work. From May 2009 to July 2013, a multiphase process was undertaken to identify an appropriate service as the basis for adaptation, collect data to inform the adaptation, adapt the testing service, develop training materials, test the adapted service, and scale up and evaluate the initial version of the service. We chose to base our adaptation on an African couples HIV testing service that was developed in the 1980s and has been widely disseminated in low- and middle-income countries. Our adaptation was informed by qualitative data collections from MSM and HIV counselors, multiple online surveys of MSM, information gathering from key stakeholders, and theater testing of the adapted service with MSM and HIV counselors. Results of initial testing indicate that the adapted service is highly acceptable to MSM and to HIV counselors, that there are no evident harms (e.g., intimate partner violence, relationship dissolution) associated with the service, and that the service identifies a substantial number of HIV serodiscordant male couples. The story of the development and scale-up of the adapted service illustrates how multiple public and foundation funding sources can collaborate to bring a prevention adaptation from concept to public health application, touching on research, program evaluation, implementation science, and public health program delivery. The result of this process is an adapted couples HIV testing approach, with training materials and handoff from academic partners to public health for assessment of effectiveness and consideration of the potential benefits of implementation; further work is needed to optimally adapt the African couples

  13. Timescales of transformational climate change adaptation in sub-Saharan African agriculture

    Science.gov (United States)

    Rippke, Ulrike; Ramirez-Villegas, Julian; Jarvis, Andy; Vermeulen, Sonja J.; Parker, Louis; Mer, Flora; Diekkrüger, Bernd; Challinor, Andrew J.; Howden, Mark

    2016-06-01

    Climate change is projected to constitute a significant threat to food security if no adaptation actions are taken. Transformation of agricultural systems, for example switching crop types or moving out of agriculture, is projected to be necessary in some cases. However, little attention has been paid to the timing of these transformations. Here, we develop a temporal uncertainty framework using the CMIP5 ensemble to assess when and where cultivation of key crops in sub-Saharan Africa becomes unviable. We report potential transformational changes for all major crops during the twenty-first century, as climates shift and areas become unsuitable. For most crops, however, transformation is limited to small pockets (banana is transformation more widespread (~30% area for maize and banana, 60% for beans). We envisage three overlapping adaptation phases to enable projected transformational changes: an incremental adaptation phase focused on improvements to crops and management, a preparatory phase that establishes appropriate policies and enabling environments, and a transformational adaptation phase in which farmers substitute crops, explore alternative livelihoods strategies, or relocate. To best align policies with production triggers for no-regret actions, monitoring capacities to track farming systems as well as climate are needed.

  14. Progesterone-based contraceptives reduce adaptive immune responses and protection against sequential influenza A virus infections.

    Science.gov (United States)

    Hall, Olivia J; Nachbagauer, Raffael; Vermillion, Meghan S; Fink, Ashley L; Phuong, Vanessa; Krammer, Florian; Klein, Sabra L

    2017-02-08

    In addition to their intended use, progesterone (P4)-based contraceptives promote anti-inflammatory immune responses, yet their effects on the outcome of infectious diseases, including influenza A virus (IAV), are rarely evaluated. To evaluate their impact on immune responses to sequential IAV infections, adult female mice were treated with placebo or one of two progestins, P4 or levonorgestrel (LNG), and infected with mouse adapted (ma) H1N1 virus. Treatment with P4 or LNG reduced morbidity, but had no effect on pulmonary virus titers, during primary H1N1 infection as compared to placebo treatment. In serum and bronchoalveolar lavage fluid, total anti-IAV IgG and IgA titers and virus neutralizing antibody titers, but not hemagglutinin stalk antibody titers, were lower in progestin-treated mice as compared with placebo-treated mice. Females were challenged six weeks later with either a maH1N1 drift variant (maH1N1dv) or maH3N2 IAV. Protection following infection with the maH1N1dv was similar among all groups. In contrast, following challenge with maH3N2, progestin treatment reduced survival as well as numbers and activity of H1N1- and H3N2-specific memory CD8+ T cells, including tissue resident cells, compared with placebo treatment. In contrast to primary IAV infection, progestin treatment increased neutralizing and IgG antibody titers against both challenge viruses compared with placebo treatment. While the immunomodulatory properties of progestins protected naïve females against severe outcome from IAV infection, it made them more susceptible to secondary challenge with a heterologous IAV, despite improving their antibody responses against a secondary IAV infection. Taken together, the immunomodulatory effects of progestins differentially regulate the outcome of infection depending on exposure history.IMPORTANCE The impact of hormone-based contraceptives on the outcome of infectious diseases outside of the reproductive tract is rarely considered. Using a mouse

  15. Guinea pig-adapted foot-and-mouth disease virus with altered receptor recognition can productively infect a natural host.

    Science.gov (United States)

    Núñez, José I; Molina, Nicolas; Baranowski, Eric; Domingo, Esteban; Clark, Stuart; Burman, Alison; Berryman, Stephen; Jackson, Terry; Sobrino, Francisco

    2007-08-01

    We report that adaptation to infect the guinea pig did not modify the capacity of foot-and-mouth disease virus (FMDV) to kill suckling mice and to cause an acute and transmissible disease in the pig, an important natural host for this pathogen. Adaptive amino acid replacements (I(248)-->T in 2C, Q(44)-->R in 3A, and L(147)-->P in VP1), selected upon serial passages of a type C FMDV isolated from swine (biological clone C-S8c1) in the guinea pig, were maintained after virus multiplication in swine and suckling mice. However, the adaptive replacement L(147)-->P, next to the integrin-binding RGD motif at the GH loop in VP1, abolished growth of the virus in different established cell lines and modified its antigenicity. In contrast, primary bovine thyroid cell cultures could be productively infected by viruses with replacement L(147)-->P, and this infection was inhibited by antibodies to alphavbeta6 and by an FMDV-derived RGD-containing peptide, suggesting that integrin alphavbeta6 may be used as a receptor for these mutants in the animal (porcine, guinea pig, and suckling mice) host. Substitution T(248)-->N in 2C was not detectable in C-S8c1 but was present in a low proportion of the guinea pig-adapted virus. This substitution became rapidly dominant in the viral population after the reintroduction of the guinea pig-adapted virus into pigs. These observations illustrate how the appearance of minority variant viruses in an unnatural host can result in the dominance of these viruses on reinfection of the original host species.

  16. Comprehensive phylogenetic reconstructions of African swine fever virus: proposal for a new classification and molecular dating of the virus.

    Directory of Open Access Journals (Sweden)

    Vincent Michaud

    Full Text Available African swine fever (ASF is a highly lethal disease of domestic pigs caused by the only known DNA arbovirus. It was first described in Kenya in 1921 and since then many isolates have been collected worldwide. However, although several phylogenetic studies have been carried out to understand the relationships between the isolates, no molecular dating analyses have been achieved so far. In this paper, comprehensive phylogenetic reconstructions were made using newly generated, publicly available sequences of hundreds of ASFV isolates from the past 70 years. Analyses focused on B646L, CP204L, and E183L genes from 356, 251, and 123 isolates, respectively. Phylogenetic analyses were achieved using maximum likelihood and Bayesian coalescence methods. A new lineage-based nomenclature is proposed to designate 35 different clusters. In addition, dating of ASFV origin was carried out from the molecular data sets. To avoid bias, diversity due to positive selection or recombination events was neutralized. The molecular clock analyses revealed that ASFV strains currently circulating have evolved over 300 years, with a time to the most recent common ancestor (TMRCA in the early 18(th century.

  17. First detection of African Swine Fever Virus in Ornithodoros porcinus in Madagascar and new insights into tick distribution and taxonomy

    Directory of Open Access Journals (Sweden)

    Albina Emmanuel

    2010-11-01

    Full Text Available Abstract Background African Swine Fever Virus has devastated more than the half of the domestic pig population in Madagascar since its introduction, probably in 1997-1998. One of the hypotheses to explain its persistence on the island is its establishment in local Ornithodoros soft ticks, whose presence has been reported in the past from the north-western coast to the Central Highlands. The aim of the present study was to verify such hypothesis by conducting tick examinations in three distinct zones of pig production in Madagascar where African Swine Fever outbreaks have been regularly reported over the past decade and then to improve our knowledge on the tick distribution and taxonomy. Results Ornithodoros ticks were only found in one pig farm in the village of Mahitsy, north-west of Antananarivo in the Central Highlands, whereas the tick seemed to be absent from the two other study zones near Ambatondrazaka and Marovoay. Using 16SrDNA PCR amplification and sequencing, it was confirmed that the collected ticks belonged to the O. porcinus species and is closely related to the O. p. domesticus sub-species Walton, 1962. ASFV was detected in 7.14% (13/182 of the field ticks through the amplification of part of the viral VP72 gene, and their ability to maintain long-term infections was confirmed since all the ticks came from a pig building where no pigs or any other potential vertebrate hosts had been introduced for at least four years. Conclusions Considering these results, O. porcinus is a reservoir for ASFV and most likely acts as vector for ASFV in Madagascar, but its apparent restricted distribution may limit its role in the epidemiology of the disease in domestic pigs.

  18. Multifunctional adaptive NS1 mutations are selected upon human influenza virus evolution in the mouse.

    Directory of Open Access Journals (Sweden)

    Nicole E Forbes

    Full Text Available The role of the NS1 protein in modulating influenza A virulence and host range was assessed by adapting A/Hong Kong/1/1968 (H3N2 (HK-wt to increased virulence in the mouse. Sequencing the NS genome segment of mouse-adapted variants revealed 11 mutations in the NS1 gene and 4 in the overlapping NEP gene. Using the HK-wt virus and reverse genetics to incorporate mutant NS gene segments, we demonstrated that all NS1 mutations were adaptive and enhanced virus replication (up to 100 fold in mouse cells and/or lungs. All but one NS1 mutant was associated with increased virulence measured by survival and weight loss in the mouse. Ten of twelve NS1 mutants significantly enhanced IFN-β antagonism to reduce the level of IFN β production relative to HK-wt in infected mouse lungs at 1 day post infection, where 9 mutants induced viral yields in the lung that were equivalent to or significantly greater than HK-wt (up to 16 fold increase. Eight of 12 NS1 mutants had reduced or lost the ability to bind the 30 kDa cleavage and polyadenylation specificity factor (CPSF30 thus demonstrating a lack of correlation with reduced IFN β production. Mutant NS1 genes resulted in increased viral mRNA transcription (10 of 12 mutants, and protein production (6 of 12 mutants in mouse cells. Increased transcription activity was demonstrated in the influenza mini-genome assay for 7 of 11 NS1 mutants. Although we have shown gain-of-function properties for all mutant NS genes, the contribution of the NEP mutations to phenotypic changes remains to be assessed. This study demonstrates that NS1 is a multifunctional virulence factor subject to adaptive evolution.

  19. Distinct lineages of Ebola virus in Guinea during the 2014 West African epidemic.

    Science.gov (United States)

    Simon-Loriere, Etienne; Faye, Ousmane; Faye, Oumar; Koivogui, Lamine; Magassouba, Nfaly; Keita, Sakoba; Thiberge, Jean-Michel; Diancourt, Laure; Bouchier, Christiane; Vandenbogaert, Matthias; Caro, Valérie; Fall, Gamou; Buchmann, Jan P; Matranga, Christan B; Sabeti, Pardis C; Manuguerra, Jean-Claude; Holmes, Edward C; Sall, Amadou A

    2015-08-06

    An epidemic of Ebola virus disease of unprecedented scale has been ongoing for more than a year in West Africa. As of 29 April 2015, there have been 26,277 reported total cases (of which 14,895 have been laboratory confirmed) resulting in 10,899 deaths. The source of the outbreak was traced to the prefecture of Guéckédou in the forested region of southeastern Guinea. The virus later spread to the capital, Conakry, and to the neighbouring countries of Sierra Leone, Liberia, Nigeria, Senegal and Mali. In March 2014, when the first cases were detected in Conakry, the Institut Pasteur of Dakar, Senegal, deployed a mobile laboratory in Donka hospital to provide diagnostic services to the greater Conakry urban area and other regions of Guinea. Through this process we sampled 85 Ebola viruses (EBOV) from patients infected from July to November 2014, and report their full genome sequences here. Phylogenetic analysis reveals the sustained transmission of three distinct viral lineages co-circulating in Guinea, including the urban setting of Conakry and its surroundings. One lineage is unique to Guinea and closely related to the earliest sampled viruses of the epidemic. A second lineage contains viruses probably reintroduced from neighbouring Sierra Leone on multiple occasions, while a third lineage later spread from Guinea to Mali. Each lineage is defined by multiple mutations, including non-synonymous changes in the virion protein 35 (VP35), glycoprotein (GP) and RNA-dependent RNA polymerase (L) proteins. The viral GP is characterized by a glycosylation site modification and mutations in the mucin-like domain that could modify the outer shape of the virion. These data illustrate the ongoing ability of EBOV to develop lineage-specific and potentially phenotypically important variation.

  20. Antigenic Variation of East/Central/South African and Asian Chikungunya Virus Genotypes in Neutralization by Immune Sera

    Science.gov (United States)

    Chua, Chong-Long; Sam, I-Ching; Merits, Andres; Chan, Yoke-Fun

    2016-01-01

    Background Chikungunya virus (CHIKV) is a re-emerging mosquito-borne virus which causes epidemics of fever, severe joint pain and rash. Between 2005 and 2010, the East/Central/South African (ECSA) genotype was responsible for global explosive outbreaks across India, the Indian Ocean and Southeast Asia. From late 2013, Asian genotype CHIKV has caused outbreaks in the Americas. The characteristics of cross-antibody efficacy and epitopes are poorly understood. Methodology/Principal Findings We characterized human immune sera collected during two independent outbreaks in Malaysia of the Asian genotype in 2006 and the ECSA genotype in 2008–2010. Neutralizing capacity was analyzed against representative clinical isolates as well as viruses rescued from infectious clones of ECSA and Asian CHIKV. Using whole virus antigen and recombinant E1 and E2 envelope glycoproteins, we further investigated antibody binding sites, epitopes, and antibody titers. Both ECSA and Asian sera demonstrated stronger neutralizing capacity against the ECSA genotype, which corresponded to strong epitope-antibody interaction. ECSA serum targeted conformational epitope sites in the E1-E2 glycoprotein, and E1-E211K, E2-I2T, E2-H5N, E2-G118S and E2-S194G are key amino acids that enhance cross-neutralizing efficacy. As for Asian serum, the antibodies targeting E2 glycoprotein correlated with neutralizing efficacy, and I2T, H5N, G118S and S194G altered and improved the neutralization profile. Rabbit polyclonal antibody against the N-terminal linear neutralizing epitope from the ECSA sequence has reduced binding capacity and neutralization efficacy against Asian CHIKV. These findings imply that the choice of vaccine strain may impact cross-protection against different genotypes. Conclusion/Significance Immune serum from humans infected with CHIKV of either ECSA or Asian genotypes showed differences in binding and neutralization characteristics. These findings have implications for the continued

  1. Molecular Detection of Torque Teno Sus Virus and Coinfection with African Swine Fever Virus in Blood Samples of Pigs from Some Slaughterhouses in Nigeria

    Directory of Open Access Journals (Sweden)

    Pam D. Luka

    2016-01-01

    Full Text Available Torque teno sus virus 1 (TTSuV1a/TTSuV1b infection is present in pig herds worldwide. This study investigated the prevalence of TTSuV1a/TTSuV1b infections in domestic pigs from some slaughterhouses in Nigeria as well as coinfection with African swine fever virus (ASFV and described the phylogeny in relation to global strains. One hundred and eighty-one (181 blood samples from four slaughterhouses were used for the study and viral nucleic acid detection was carried out by PCR. Comparative sequence analysis was carried out to infer phylogeny. The overall prevalence of TTSuV1a/b was 17.7%. Prevalence of individual genotypes was 10.5% and 7.2% for TTSuV1a and TTSuV1b, respectively. Coinfection of ASFV/TTSuV1a/b was 7.7% while that of TTSuV1a and TTSuV1b was 1.7%. ASFV alone was detected in 11.91% of the total samples. The Nigerian TTSuV1a and TTSuV1b shared a sequence identity of 91–100% and 95–100%, respectively, among each other. The ASFV sequences were 100% identical to members of genotype 1. This is the first report on the presence of TTSuV1a/b in domestic pigs in Nigeria and coinfection with ASFV. Although the prevalence of TTSuV1a/b in Nigeria was low, we recommend further studies to establish the trend and possible role in the pathogenesis of ASFV.

  2. Molecular Detection of Torque Teno Sus Virus and Coinfection with African Swine Fever Virus in Blood Samples of Pigs from Some Slaughterhouses in Nigeria

    Science.gov (United States)

    Erume, Joseph; Yakubu, Bitrus; Owolodun, Olajide A.; Shamaki, David

    2016-01-01

    Torque teno sus virus 1 (TTSuV1a/TTSuV1b) infection is present in pig herds worldwide. This study investigated the prevalence of TTSuV1a/TTSuV1b infections in domestic pigs from some slaughterhouses in Nigeria as well as coinfection with African swine fever virus (ASFV) and described the phylogeny in relation to global strains. One hundred and eighty-one (181) blood samples from four slaughterhouses were used for the study and viral nucleic acid detection was carried out by PCR. Comparative sequence analysis was carried out to infer phylogeny. The overall prevalence of TTSuV1a/b was 17.7%. Prevalence of individual genotypes was 10.5% and 7.2% for TTSuV1a and TTSuV1b, respectively. Coinfection of ASFV/TTSuV1a/b was 7.7% while that of TTSuV1a and TTSuV1b was 1.7%. ASFV alone was detected in 11.91% of the total samples. The Nigerian TTSuV1a and TTSuV1b shared a sequence identity of 91–100% and 95–100%, respectively, among each other. The ASFV sequences were 100% identical to members of genotype 1. This is the first report on the presence of TTSuV1a/b in domestic pigs in Nigeria and coinfection with ASFV. Although the prevalence of TTSuV1a/b in Nigeria was low, we recommend further studies to establish the trend and possible role in the pathogenesis of ASFV. PMID:27833640

  3. Adaptation of Influenza A Viruses to Cells Expressing Low Levels of Sialic Acid Leads to Loss of Neuraminidase Activity

    OpenAIRE

    2001-01-01

    Influenza A viruses possess two virion surface proteins, hemagglutinin (HA) and neuraminidase (NA). The HA binds to sialyloligosaccharide viral receptors, while the NA removes sialic acids from the host cell and viral sialyloligosaccarides. Alterations of the HA occur during adaptation of influenza viruses to new host species, as in the 1957 and 1968 influenza pandemics. To gain a better understanding of the contributions of the HA and possibly the NA to this process, we generated cell lines ...

  4. Hepatitis B virus infection in human immunodeficiency virus infected southern African adults: occult or overt--that is the question.

    Directory of Open Access Journals (Sweden)

    Trevor G Bell

    Full Text Available Hepatitis B virus (HBV and human immunodeficiency virus (HIV share transmission routes and are endemic in sub-Saharan Africa. The objective of the present study was to use the Taormina definition of occult HBV infection, together with stringent amplification conditions, to determine the prevalence and characteristics of HBV infection in antiretroviral treatment (ART-naïve HIV(+ve adults in a rural cohort in South Africa. The presence of HBV serological markers was determined by enzyme linked immunoassay (ELISA tests. HBV DNA-positivity was determined by polymerase chain reaction (PCR of at least two of three different regions of the HBV genome. HBV viral loads were determined by real-time PCR. Liver fibrosis was determined using the aspartate aminotransferase-to-platelet ratio index. Of the 298 participants, 231 (77.5% showed at least one HBV marker, with 53.7% HBV DNA(-ve (resolved and 23.8% HBV DNA(+ve (current [8.7% HBsAg(+ve: 15.1% HBsAg(-ve]. Only the total number of sexual partners distinguished HBV DNA(+ve and HBV DNA(-ve participants, implicating sexual transmission of HBV and/or HIV. It is plausible that sexual transmission of HBV and/or HIV may result in a new HBV infection, superinfection and re-activation as a consequence of immunesuppression. Three HBsAg(-ve HBV DNA(+ve participants had HBV viral loads <200 IU/ml and were therefore true occult HBV infections. The majority of HBsAg(-ve HBV DNA(+ve participants did not differ from HBsAg(+ve HBV DNA(+ve (overt participants in terms of HBV viral loads, ALT levels or frequency of liver fibrosis. Close to a quarter of HIV(+ve participants were HBV DNA(+ve, of which the majority were HBsAg(-ve and were only detected using nucleic acid testing. Detection of HBsAg(-ve HBV DNA(+ve subjects is advisable considering they were clinically indistinguishable from HBsAg(+ve HBV DNA(+ve individuals and should not be overlooked, especially if lamivudine is included in the ART.

  5. Modulation of chemokine and chemokine receptor expression following infection of porcine macrophages with African swine fever virus.

    Science.gov (United States)

    Fishbourne, Emma; Abrams, Charles C; Takamatsu, Haru-H; Dixon, Linda K

    2013-03-23

    African swine fever virus (ASFV) is the only member of the Asfarviridae, a large DNA virus family which replicates predominantly in the cytoplasm. Most isolates cause a fatal haemorrhagic disease in domestic pigs, although some low virulence isolates cause little or no mortality. The modulation of chemokine responses following infection of porcine macrophages with low and high virulence isolates was studied to indicate how this may be involved in the induction of pathogenesis and of effective immune responses. Infection with both low and high virulence isolates resulted in down-regulation of mRNA levels for chemokines CCL2, CCL3L, CXCL2 and chemokine receptors CCR1, CCR5, CXCR3, CXCR4 and up-regulation in expression of mRNAs for CCL4, CXCL10 and chemokine receptor CCR7. Levels of CCL4, CXCL8, CXCL10 mRNAs were higher in macrophages infected with low virulence isolate OURT88/3 compared to high virulence isolate Benin 97/1. Levels of CXCL8 and CCL2 protein were significantly reduced in supernatants from macrophages infected with Benin 97/1 isolate compared to OURT88/3 and mock-infected macrophages. There was also a decreased chemotactic response of donor cells exposed to supernatants from Benin 97/1 infected macrophages compared to those from OURT88/3 and mock-infected macrophages. The data show that infection of macrophages with the low virulence strain OURT88/3 induces higher expression of key inflammatory chemokines compared to infection with high virulence strain Benin 97/1. This may be important for the induction of effective protective immunity that has been observed in pigs immunised with the OURT88/3 isolate.

  6. Dynamics of African swine fever virus shedding and excretion in domestic pigs infected by intramuscular inoculation and contact transmission.

    Science.gov (United States)

    Guinat, Claire; Reis, Ana Luisa; Netherton, Christopher L; Goatley, Lynnette; Pfeiffer, Dirk U; Dixon, Linda

    2014-09-26

    African swine fever virus (ASFV) is a highly virulent swine pathogen that has spread across Eastern Europe since 2007 and for which there is no effective vaccine or treatment available. The dynamics of shedding and excretion is not well known for this currently circulating ASFV strain. Therefore, susceptible pigs were exposed to pigs intramuscularly infected with the Georgia 2007/1 ASFV strain to measure those dynamics through within- and between-pen transmission scenarios. Blood, oral, nasal and rectal fluid samples were tested for the presence of ASFV by virus titration (VT) and quantitative real-time polymerase chain reaction (qPCR). Serum was tested for the presence of ASFV-specific antibodies. Both intramuscular inoculation and contact transmission resulted in development of acute disease in all pigs although the experiments indicated that the pathogenesis of the disease might be different, depending on the route of infection. Infectious ASFV was first isolated in blood among the inoculated pigs by day 3, and then chronologically among the direct and indirect contact pigs, by day 10 and 13, respectively. Close to the onset of clinical signs, higher ASFV titres were found in blood compared with nasal and rectal fluid samples among all pigs. No infectious ASFV was isolated in oral fluid samples although ASFV genome copies were detected. Only one animal developed antibodies starting after 12 days post-inoculation. The results provide quantitative data on shedding and excretion of the Georgia 2007/1 ASFV strain among domestic pigs and suggest a limited potential of this isolate to cause persistent infection.

  7. African swine fever virus: current state and future perspectives in vaccine and antiviral research.

    Science.gov (United States)

    Zakaryan, Hovakim; Revilla, Yolanda

    2016-03-15

    African swine fever (ASF) is among the most significant of swine diseases for which no effective vaccines and antivirals are available. The disease, which is endemic in Africa, was introduced to Trans-Caucasian countries and the Russian Federation in 2007, where it remains prevalent today among domestic pigs and wild boars. Although some measures were implemented, ASF continues to pose a global risk for all countries, and thereby highlighting the importance of vaccine and antiviral research. In this review, an overview of research efforts toward the development of effective vaccines during the past decades is presented. As an alternative to vaccine development, the current state in antiviral research against ASFV is also presented. Finally, future perspectives in vaccine and antiviral research giving emphasis on some strategies that may allow researchers to develop effective countermeasures against ASF are discussed.

  8. Experimental adaptation of wild-type canine distemper virus (CDV) to the human entry receptor CD150.

    Science.gov (United States)

    Bieringer, Maria; Han, Jung Woo; Kendl, Sabine; Khosravi, Mojtaba; Plattet, Philippe; Schneider-Schaulies, Jürgen

    2013-01-01

    Canine distemper virus (CDV), a close relative of measles virus (MV), is widespread and well known for its broad host range. When the goal of measles eradication may be achieved, and when measles vaccination will be stopped, CDV might eventually cross the species barrier to humans and emerge as a new human pathogen. In order to get an impression how fast such alterations may occur, we characterized required adaptive mutations to the human entry receptors CD150 (SLAM) and nectin-4 as first step to infect human target cells. Recombinant wild-type CDV-A75/17(red) adapted quickly to growth in human H358 epithelial cells expressing human nectin-4. Sequencing of the viral attachment proteins (hemagglutinin, H, and fusion protein, F) genes revealed that no adaptive alteration was required to utilize human nectin-4. In contrast, the virus replicated only to low titres (10(2) pfu/ml) in Vero cells expressing human CD150 (Vero-hSLAM). After three passages using these cells virus was adapted to human CD150 and replicated to high titres (10(5) pfu/ml). Sequence analyses revealed that only one amino acid exchange in the H-protein at position 540 Asp→Gly (D540G) was required for functional adaptation to human CD150. Structural modelling suggests that the adaptive mutation D540G in H reflects the sequence alteration from canine to human CD150 at position 70 and 71 from Pro to Leu (P70L) and Gly to Glu (G71E), and compensates for the gain of a negative charge in the human CD150 molecule. Using this model system our data indicate that only a minimal alteration, in this case one adaptive mutation, is required for adaptation of CDV to the human entry receptors, and help to understand the molecular basis why this adaptive mutation occurs.

  9. Experimental adaptation of wild-type canine distemper virus (CDV to the human entry receptor CD150.

    Directory of Open Access Journals (Sweden)

    Maria Bieringer

    Full Text Available Canine distemper virus (CDV, a close relative of measles virus (MV, is widespread and well known for its broad host range. When the goal of measles eradication may be achieved, and when measles vaccination will be stopped, CDV might eventually cross the species barrier to humans and emerge as a new human pathogen. In order to get an impression how fast such alterations may occur, we characterized required adaptive mutations to the human entry receptors CD150 (SLAM and nectin-4 as first step to infect human target cells. Recombinant wild-type CDV-A75/17(red adapted quickly to growth in human H358 epithelial cells expressing human nectin-4. Sequencing of the viral attachment proteins (hemagglutinin, H, and fusion protein, F genes revealed that no adaptive alteration was required to utilize human nectin-4. In contrast, the virus replicated only to low titres (10(2 pfu/ml in Vero cells expressing human CD150 (Vero-hSLAM. After three passages using these cells virus was adapted to human CD150 and replicated to high titres (10(5 pfu/ml. Sequence analyses revealed that only one amino acid exchange in the H-protein at position 540 Asp→Gly (D540G was required for functional adaptation to human CD150. Structural modelling suggests that the adaptive mutation D540G in H reflects the sequence alteration from canine to human CD150 at position 70 and 71 from Pro to Leu (P70L and Gly to Glu (G71E, and compensates for the gain of a negative charge in the human CD150 molecule. Using this model system our data indicate that only a minimal alteration, in this case one adaptive mutation, is required for adaptation of CDV to the human entry receptors, and help to understand the molecular basis why this adaptive mutation occurs.

  10. SPACES Project ARS AfricaE – Adaptive Resilience of Southern African ecosystems

    Science.gov (United States)

    Falge, Eva; Brümmer, Christian; Schmullius, Christiane; Hüttich, Christian; Scholes, Robert John; Midgley, Guy; Hickler, Thomas; Scheiter, Simon; Twine, Wayne; Bradshaw, Karen; Lück, Wolfgang; Thiel-Clemen, Thomas; Lenfers, Ulfia; Mukelabai, Mukufute; Kutsch, Werner

    2015-04-01

    Nowadays, many semi-arid ecosystems are affected by at least two different kinds of disturbances: land use (change) and climate change. Based on this, it can be hypothesized that even very resilient ecosystems may not return to their initial state after disturbance, but will rather adapt to a new steady-state. We name this phenomenon "Adaptive Resilience of Ecosystems" and use it as base for the research concept of ARS AfricaE. This project wants to go beyond older approaches that only describe structural changes in savannas and their drivers. It employs functional aspects, such as the investigation of biogeochemical cycles, but also targets a deeper understanding of the functional consequences of ecosystem changes caused by multiple disturbances, and defines "degradation" as a sustained loss in the broad set of ecosystem services, i.e. a decrease in natural capital. To achieve this goal, the project will • create a network of research clusters (with natural and altered vegetation) along an aridity gradient in the Greater Karoo, Kruger National Park in South Africa, and Kataba Forest Reserve in Zambia • link biogeochemical functions with ecosystem structure, diversity of species and eco-physiological properties • describe ecosystem disturbance (and recovery) in terms of ecosystem function such as carbon balance components and water use efficiency • build an individual-based model to predict ecosystem dynamics under (post) disturbance managements • combine this model with long-term landscape dynamic information derived from remote sensing and aerial photography • develop sustainable management strategies for disturbed ecosystems and land use change

  11. Canine distemper virus associated with a lethal outbreak in monkeys can readily adapt to use human receptors.

    Science.gov (United States)

    Sakai, Kouji; Yoshikawa, Tomoki; Seki, Fumio; Fukushi, Shuetsu; Tahara, Maino; Nagata, Noriyo; Ami, Yasushi; Mizutani, Tetsuya; Kurane, Ichiro; Yamaguchi, Ryoji; Hasegawa, Hideki; Saijo, Masayuki; Komase, Katsuhiro; Morikawa, Shigeru; Takeda, Makoto

    2013-06-01

    A canine distemper virus (CDV) strain, CYN07-dV, associated with a lethal outbreak in monkeys, used human signaling lymphocyte activation molecule as a receptor only poorly but readily adapted to use it following a P541S substitution in the hemagglutinin protein. Since CYN07-dV had an intrinsic ability to use human nectin-4, the adapted virus became able to use both human immune and epithelial cell receptors, as well as monkey and canine ones, suggesting that CDV can potentially infect humans.

  12. Stoichiometry of monoclonal antibody neutralization of T-cell line-adapted human immunodeficiency virus type 1

    DEFF Research Database (Denmark)

    Schønning, Kristian; Lund, O; Lund, O S;

    1999-01-01

    In order to study the stoichiometry of monoclonal antibody (MAb) neutralization of T-cell line-adapted human immunodeficiency virus type 1 (HIV-1) in antibody excess and under equilibrium conditions, we exploited the ability of HIV-1 to generate mixed oligomers when different env genes are coexpr......In order to study the stoichiometry of monoclonal antibody (MAb) neutralization of T-cell line-adapted human immunodeficiency virus type 1 (HIV-1) in antibody excess and under equilibrium conditions, we exploited the ability of HIV-1 to generate mixed oligomers when different env genes...

  13. Vaccine Potential of Two Previously Uncharacterized African Swine Fever Virus Isolates from Southern Africa and Heterologous Cross Protection of an Avirulent European Isolate.

    Science.gov (United States)

    Souto, R; Mutowembwa, P; van Heerden, J; Fosgate, G T; Heath, L; Vosloo, W

    2016-04-01

    African swine fever (ASF) is a mostly fatal viral infection of domestic pigs for which there is no vaccine available. The disease is endemic to most of sub-Saharan Africa, causes severe losses and threatens food security in large parts of the continent. Naturally occurring attenuated ASF viruses have been tested as vaccine candidates, but protection was variable depending on the challenge virus. In this study, the virulence of two African isolates, one from a tick vector and the other from an indigenous pig, was determined in domestic pigs to identify a potential vaccine strain for southern Africa. Neither isolate was suitable as the tick isolate was moderately virulent and the indigenous pig virus was highly virulent. The latter was subsequently used as heterologous challenge in pigs first vaccinated with a naturally attenuated isolate previously isolated in Portugal. Although a statistically significant reduction in death rate and virus load was observed compared with unvaccinated pigs post-challenge, all pigs succumbed to infection and died.

  14. Comparison of West African and Congo Basin monkeypox viruses in BALB/c and C57BL/6 mice.

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    Christina L Hutson

    Full Text Available Although monkeypox virus (MPXV studies in wild rodents and non-human primates have generated important knowledge regarding MPXV pathogenesis and inferences about disease transmission, it might be easier to dissect the importance of virulence factors and correlates of protection to MPXV in an inbred mouse model. Herein, we compared the two clades of MPXV via two routes of infection in the BALB/c and C57BL/6 inbred mice strains. Our studies show that similar to previous animal studies, the Congo Basin strain of MPXV was more virulent than West African MPXV in both mouse strains as evidenced by clinical signs. Although animals did not develop lesions as seen in human MPX infections, localized signs were apparent with the foot pad route of inoculation, primarily in the form of edema at the site of inoculation; while the Congo Basin intranasal route of infection led to generalized symptoms, primarily weight loss. We have determined that future studies with MPXV and laboratory mice would be very beneficial in understanding the pathogenesis of MPXV, in particular if used in in vivo imaging studies. Although this mouse model may not suffice as a model of human MPX disease, with an appropriate inbred mouse model, we can unravel many unknown aspects of MPX pathogenesis, including virulence factors, disease progression in rodent hosts, and viral shedding from infected animals. In addition, such a model can be utilized to test antivirals and the next generation of orthopoxvirus vaccines for their ability to alter the course of disease.

  15. A study of lymphoid organs and serum proinflammatory cytokines in pigs infected with African swine fever virus genotype II.

    Science.gov (United States)

    Zakaryan, Hovakim; Cholakyans, Victorya; Simonyan, Lusine; Misakyan, Alla; Karalova, Elena; Chavushyan, Andranik; Karalyan, Zaven

    2015-06-01

    African swine fever virus (ASFV), the causative agent of one of the most important viral diseases of domestic pigs for which no vaccine is available, causes immune system disorders in infected animals. In this study, the serum levels of proinflammatory cytokines, as well as the histological and cellular constitution of lymphoid organs of pigs infected with ASFV genotype II were investigated. The results showed a high degree of lymphocyte depletion in the lymphoid organs, particularly in the spleen and lymph nodes, where ASFV infection led to a twofold decrease in the number of lymphocytes on the final day of infection. Additionally, ASFV-infected pigs had atypical forms of lymphocytes found in all lymphoid organs. In contrast to lymphocytes, the number of immature immune cells, particularly myelocytes, increased dramatically and reached a maximum on day 7 postinfection. The serum levels of TNF-α, IL-1β, IL-6, and IL-8 were evaluated. Proinflammatory cytokines showed increased levels after ASFV infection, with peak values at 7 days postinfection, and this highlights their role in the pathogenesis of ASFV. In conclusion, this study showed that ASFV genotype II, like other highly virulent strains, causes severe pathological changes in the immune system of pigs.

  16. Predominance of hepatitis C virus genotype 4 infection and rapid transmission between 1935 and 1965 in the Central African Republic.

    Science.gov (United States)

    Njouom, Richard; Frost, Eric; Deslandes, Sylvie; Mamadou-Yaya, Fleurie; Labbé, Annie-Claude; Pouillot, Régis; Mbélesso, Pascal; Mbadingai, Sylvestre; Rousset, Dominique; Pépin, Jacques

    2009-10-01

    The molecular epidemiology of hepatitis C virus (HCV) in the Central African Republic (CAR) is poorly documented. Thus, we conducted phylogenetic analyses of NS5B gene sequences from 58 HCV-infected inhabitants of a remote area of south-west CAR, which indicated that 48 (82.8%) were infected with genotype 4 (HCV-4), five (8.6%) with genotype 2 and five (8.6%) with genotype 1. HCV-4 strains were highly heterogeneous, containing previously described subtypes 4k (48%), 4c (27%), 4r (4%), 4f (4%) and unclassified subtypes (17%). To estimate the epidemic history of these HCV-4 strains, an evolutionary analysis using the coalescent approach was used. The estimated date of the most recent common ancestor of the CAR HCV-4 strains was 1539 (95% confidence intervals, 1317-1697). They exhibited a rapid, exponential spread from 1935 to 1965, simultaneously with what was recently reported in neighbouring Cameroon and Gabon. The hypothesis of a massive iatrogenic transmission during interventions for the control of endemic tropical diseases is discussed.

  17. Body temperature daily rhythm adaptations in African savanna elephants (Loxodonta africana).

    Science.gov (United States)

    Kinahan, A A; Inge-moller, R; Bateman, P W; Kotze, A; Scantlebury, M

    2007-11-23

    The savanna elephant is the largest extant mammal and often inhabits hot and arid environments. Due to their large size, it might be expected that elephants have particular physiological adaptations, such as adjustments to the rhythms of their core body temperature (T(b)) to deal with environmental challenges. This study describes for the first time the T(b) daily rhythms in savanna elephants. Our results showed that elephants had lower mean T(b) values (36.2 +/- 0.49 degrees C) than smaller ungulates inhabiting similar environments but did not have larger or smaller amplitudes of T(b) variation (0.40 +/- 0.12 degrees C), as would be predicted by their exposure to large fluctuations in ambient temperature or their large size. No difference was found between the daily T(b) rhythms measured under different conditions of water stress. Peak T(b)'s occurred late in the evening (22:10) which is generally later than in other large mammals ranging in similar environmental conditions.

  18. Experimental Infection of Ornithodoros erraticus sensu stricto with Two Portuguese African Swine Fever Virus Strains. Study of Factors Involved in the Dynamics of Infection in Ticks.

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    Rita Ribeiro

    Full Text Available African swine fever (ASF is a frequently devastating hemorrhagic disease of domestic pigs and wild boar and Ornithodoros erraticus sensu stricto argasid ticks are the only biological vectors of African swine fever virus (ASFV known to occur in Europe. Recently this disease emerged in Eastern Europe and Russian Federation, showing a huge potential for a rapid spread between countries. There is some risk of re-emergence of ASF in the countries where these ticks exist, that can contribute for the persistence of infection and compromise control measures. In this study we aimed to identify factors that determine the probability of infection and its dynamics in the tick vector Ornithodoros erraticus sensu stricto, with two Portuguese strains of ASFV. Our results suggest that these ticks have a high likelihood of excreting the two haemadsorbing ASF viruses of different host origins and that, in field surveys, the analysis of adults and 5th nymphal stage can provide the best chance of detecting virus infection. The results also indicate that infection of pigs with highly virulent ASF viruses will promote higher rates of infection and a higher likelihood for virus excretion by ticks. Nevertheless, there is also a risk, although lower, that ticks can become infected on pigs that have overcome the acute phase of infection, which was simulated in our study by membrane feeding ticks with low titres of virus. We believe these results can be valuable in designing and interpreting the results of ASF control programmes, and future work can also be undertaken as our dataset is released under open access, to perform studies in risk assessment for ASFV persistence in a region where O. erraticus sensu stricto ticks are present.

  19. Experimental Infection of Ornithodoros erraticus sensu stricto with Two Portuguese African Swine Fever Virus Strains. Study of Factors Involved in the Dynamics of Infection in Ticks.

    Science.gov (United States)

    Ribeiro, Rita; Otte, Joachim; Madeira, Sara; Hutchings, Geoff H; Boinas, Fernando

    2015-01-01

    African swine fever (ASF) is a frequently devastating hemorrhagic disease of domestic pigs and wild boar and Ornithodoros erraticus sensu stricto argasid ticks are the only biological vectors of African swine fever virus (ASFV) known to occur in Europe. Recently this disease emerged in Eastern Europe and Russian Federation, showing a huge potential for a rapid spread between countries. There is some risk of re-emergence of ASF in the countries where these ticks exist, that can contribute for the persistence of infection and compromise control measures. In this study we aimed to identify factors that determine the probability of infection and its dynamics in the tick vector Ornithodoros erraticus sensu stricto, with two Portuguese strains of ASFV. Our results suggest that these ticks have a high likelihood of excreting the two haemadsorbing ASF viruses of different host origins and that, in field surveys, the analysis of adults and 5th nymphal stage can provide the best chance of detecting virus infection. The results also indicate that infection of pigs with highly virulent ASF viruses will promote higher rates of infection and a higher likelihood for virus excretion by ticks. Nevertheless, there is also a risk, although lower, that ticks can become infected on pigs that have overcome the acute phase of infection, which was simulated in our study by membrane feeding ticks with low titres of virus. We believe these results can be valuable in designing and interpreting the results of ASF control programmes, and future work can also be undertaken as our dataset is released under open access, to perform studies in risk assessment for ASFV persistence in a region where O. erraticus sensu stricto ticks are present.

  20. Sequences enhancing cassava mosaic disease symptoms occur in the cassava genome and are associated with South African cassava mosaic virus infection.

    Science.gov (United States)

    Maredza, A T; Allie, F; Plata, G; Rey, M E C

    2016-06-01

    Cassava is an important food security crop in Sub-Saharan Africa. Two episomal begomovirus-associated sequences, named Sequences Enhancing Geminivirus Symptoms (SEGS1 and SEGS2), were identified in field cassava affected by the devastating cassava mosaic disease (CMD). The sequences reportedly exacerbated CMD symptoms in the tolerant cassava landrace TME3, and the model plants Arabidopsis thaliana and Nicotiana benthamiana, when biolistically co-inoculated with African cassava mosaic virus-Cameroon (ACMV-CM) or East African cassava mosaic virus-UG2 (EACMV-UG2). Following the identification of small SEGS fragments in the cassava EST database, the intention of this study was to confirm their presence in the genome, and investigate a possible role for these sequences in CMD. We report that multiple copies of varying lengths of both SEGS1 and SEGS2 are widely distributed in the sequenced cassava genome and are present in several other cassava accessions screened by PCR. The endogenous SEGS1 and SEGS2 are in close proximity or overlapping with cassava genes, suggesting a possible role in regulation of specific biological processes. We confirm the expression of SEGS in planta using EST data and RT-PCR. The sequence features of endogenous SEGS (iSEGS) are unique but resemble non-autonomous transposable elements (TEs) such as MITEs and helitrons. Furthermore, many SEGS-associated genes, some involved in virus-host interactions, are differentially expressed in susceptible (T200) and tolerant TME3) cassava landraces infected by South African cassava mosaic virus (SACMV) of susceptible (T200) and tolerant (TME3) cassava landraces. Abundant SEGS-derived small RNAs were also present in mock-inoculated and SACMV-infected T200 and TME3 leaves. Given the known role of TEs and associated genes in gene regulation and plant immune responses, our observations are consistent with a role of these DNA elements in the host's regulatory response to geminiviruses.

  1. Adaptation of the Haloarcula hispanica CRISPR-Cas system to a purified virus strictly requires a priming process.

    Science.gov (United States)

    Li, Ming; Wang, Rui; Zhao, Dahe; Xiang, Hua

    2014-02-01

    The clustered regularly interspaced short palindromic repeat (CRISPR)-Cas system mediates adaptive immunity against foreign nucleic acids in prokaryotes. However, efficient adaptation of a native CRISPR to purified viruses has only been observed for the type II-A system from a Streptococcus thermophilus industry strain, and rarely reported for laboratory strains. Here, we provide a second native system showing efficient adaptation. Infected by a newly isolated virus HHPV-2, Haloarcula hispanica type I-B CRISPR system acquired spacers discriminatively from viral sequences. Unexpectedly, in addition to Cas1, Cas2 and Cas4, this process also requires Cas3 and at least partial Cascade proteins, which are involved in interference and/or CRISPR RNA maturation. Intriguingly, a preexisting spacer partially matching a viral sequence is also required, and spacer acquisition from upstream and downstream sequences of its target sequence (i.e. priming protospacer) shows different strand bias. These evidences strongly indicate that adaptation in this system strictly requires a priming process. This requirement, if validated also true for other CRISPR systems as implied by our bioinformatic analysis, may help to explain failures to observe efficient adaptation to purified viruses in many laboratory strains, and the discrimination mechanism at the adaptation level that has confused scientists for years.

  2. [Real-time PCR kits for the detection of the African Swine Fever virus].

    Science.gov (United States)

    Latyshev, O E; Eliseeva, O V; Grebennikova, T V; Verkhovskiĭ, O A; Tsibezov, V V; Chernykh, O Iu; Dzhailidi, G A; Aliper, T I

    2014-01-01

    The results obtained using the diagnostic kit based on real-time polymerase chain reaction to detect the DNA of the African Swine Fever in the pathological material, as well as in the culture fluid, are presented. A high sensitivity and specificity for detection of the DNA in the organs and tissues of animals was shown to be useful for detection in the European Union referentiality reagent kits for DNA detection by real time PCR of ASFV. More rapid and effective method of DNA extraction using columns mini spin Quick gDNA(TM) MiniPrep was suggested and compared to the method of DNA isolation on the inorganic sorbent. High correlation of the results of the DNA detection of ASFV by real-time PCR and antigen detection results ASFV by competitive ELISA obtained with the ELISA SEROTEST/INGEZIM COMRAC PPA was demonstrated. The kit can be used in the veterinary services for effective monitoring of ASFV to contain, eliminate and prevent further spread of the disease.

  3. Drivers and risk factors for circulating African swine fever virus in Uganda, 2012-2013.

    Science.gov (United States)

    Kabuuka, T; Kasaija, P D; Mulindwa, H; Shittu, A; Bastos, A D S; Fasina, F O

    2014-10-01

    We explored observed risk factors and drivers of infection possibly associated with African swine fever (ASF) epidemiology in Uganda. Representative sub-populations of pig farms and statistics were used in a case-control model. Indiscriminate disposal of pig viscera and waste materials after slaughter, including on open refuse dumps, farm-gate buyers collecting pigs and pig products from within a farm, and retention of survivor pigs were plausible risk factors. Wire mesh-protected windows in pig houses were found to be protective against ASF infection. Sighting engorged ticks on pigs, the presence of a lock for each pig pen and/or a gate at the farm entrance were significantly associated with infection/non-infection; possible explanations were offered. Strict adherence to planned within-farm and community-based biosecurity, and avoidance of identified risk factors is recommended to reduce infection. Training for small-scale and emerging farmers should involve multidimensional and multidisciplinary approaches to reduce human-related risky behaviours driving infection.

  4. Adaptation of high-growth influenza H5N1 vaccine virus in Vero cells: implications for pandemic preparedness.

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    Yu-Fen Tseng

    Full Text Available Current egg-based influenza vaccine production technology can't promptly meet the global demand during an influenza pandemic as shown in the 2009 H1N1 pandemic. Moreover, its manufacturing capacity would be vulnerable during pandemics caused by highly pathogenic avian influenza viruses. Therefore, vaccine production using mammalian cell technology is becoming attractive. Current influenza H5N1 vaccine strain (NIBRG-14, a reassortant virus between A/Vietnam/1194/2004 (H5N1 virus and egg-adapted high-growth A/PR/8/1934 virus, could grow efficiently in eggs and MDCK cells but not Vero cells which is the most popular cell line for manufacturing human vaccines. After serial passages and plaque purifications of the NIBRG-14 vaccine virus in Vero cells, one high-growth virus strain (Vero-15 was generated and can grow over 10(8 TCID(50/ml. In conclusion, one high-growth H5N1 vaccine virus was generated in Vero cells, which can be used to manufacture influenza H5N1 vaccines and prepare reassortant vaccine viruses for other influenza A subtypes.

  5. Comparisons of clustered regularly interspaced short palindromic repeats and viromes in human saliva reveal bacterial adaptations to salivary viruses.

    Science.gov (United States)

    Pride, David T; Salzman, Julia; Relman, David A

    2012-09-01

    Explorations of human microbiota have provided substantial insight into microbial community composition; however, little is known about interactions between various microbial components in human ecosystems. In response to the powerful impact of viral predation, bacteria have acquired potent defences, including an adaptive immune response based on the clustered regularly interspaced short palindromic repeats (CRISPRs)/Cas system. To improve our understanding of the interactions between bacteria and their viruses in humans, we analysed 13 977 streptococcal CRISPR sequences and compared them with 2 588 172 virome reads in the saliva of four human subjects over 17 months. We found a diverse array of viruses and CRISPR spacers, many of which were specific to each subject and time point. There were numerous viral sequences matching CRISPR spacers; these matches were highly specific for salivary viruses. We determined that spacers and viruses coexist at the same time, which suggests that streptococcal CRISPR/Cas systems are under constant pressure from salivary viruses. CRISPRs in some subjects were just as likely to match viral sequences from other subjects as they were to match viruses from the same subject. Because interactions between bacteria and viruses help to determine the structure of bacterial communities, CRISPR-virus analyses are likely to provide insight into the forces shaping the human microbiome.

  6. Acute diarrhea in West African children: diverse enteric viruses and a novel parvovirus genus.

    Science.gov (United States)

    Phan, Tung G; Vo, Nguyen P; Bonkoungou, Isidore J O; Kapoor, Amit; Barro, Nicolas; O'Ryan, Miguel; Kapusinszky, Beatrix; Wang, Chunling; Delwart, Eric

    2012-10-01

    Parvoviruses cause a variety of mild to severe symptoms or asymptomatic infections in humans and animals. During a viral metagenomic analysis of feces from children with acute diarrhea in Burkina Faso, we identified in decreasing prevalence nucleic acids from anelloviruses, dependoviruses, sapoviruses, enteroviruses, bocaviruses, noroviruses, adenoviruses, parechoviruses, rotaviruses, cosavirus, astroviruses, and hepatitis B virus. Sequences from a highly divergent parvovirus, provisionally called bufavirus, were also detected whose NS1 and VP1 proteins showed parvoviruses. Four percent of the fecal samples were PCR positive for this new parvovirus, including a related bufavirus species showing only 72% identity in VP1. The high degree of genetic divergence of these related genomes from those of other parvoviruses indicates the presence of a proposed new Parvoviridae genus containing at least two species. Studies of the tropism and pathogenicity of these novel parvoviruses will be facilitated by the availability of their genome sequences.

  7. Rational Design and Adaptive Management of Combination Therapies for Hepatitis C Virus Infection.

    Directory of Open Access Journals (Sweden)

    Ruian Ke

    2015-06-01

    Full Text Available Recent discoveries of direct acting antivirals against Hepatitis C virus (HCV have raised hopes of effective treatment via combination therapies. Yet rapid evolution and high diversity of HCV populations, combined with the reality of suboptimal treatment adherence, make drug resistance a clinical and public health concern. We develop a general model incorporating viral dynamics and pharmacokinetics/ pharmacodynamics to assess how suboptimal adherence affects resistance development and clinical outcomes. We derive design principles and adaptive treatment strategies, identifying a high-risk period when missing doses is particularly risky for de novo resistance, and quantifying the number of additional doses needed to compensate when doses are missed. Using data from large-scale resistance assays, we demonstrate that the risk of resistance can be reduced substantially by applying these principles to a combination therapy of daclatasvir and asunaprevir. By providing a mechanistic framework to link patient characteristics to the risk of resistance, these findings show the potential of rational treatment design.

  8. Rational Design and Adaptive Management of Combination Therapies for Hepatitis C Virus Infection

    Science.gov (United States)

    Ke, Ruian; Loverdo, Claude; Qi, Hangfei; Sun, Ren; Lloyd-Smith, James O.

    2015-01-01

    Recent discoveries of direct acting antivirals against Hepatitis C virus (HCV) have raised hopes of effective treatment via combination therapies. Yet rapid evolution and high diversity of HCV populations, combined with the reality of suboptimal treatment adherence, make drug resistance a clinical and public health concern. We develop a general model incorporating viral dynamics and pharmacokinetics/ pharmacodynamics to assess how suboptimal adherence affects resistance development and clinical outcomes. We derive design principles and adaptive treatment strategies, identifying a high-risk period when missing doses is particularly risky for de novo resistance, and quantifying the number of additional doses needed to compensate when doses are missed. Using data from large-scale resistance assays, we demonstrate that the risk of resistance can be reduced substantially by applying these principles to a combination therapy of daclatasvir and asunaprevir. By providing a mechanistic framework to link patient characteristics to the risk of resistance, these findings show the potential of rational treatment design. PMID:26125950

  9. Adaptation of human and simian immunodeficiency viruses for resistance to tetherin/BST-2.

    Science.gov (United States)

    Serra-Moreno, Ruth; Evans, David T

    2012-06-01

    Tetherin (BST-2 or CD317) is an interferon-inducible cellular factor that prevents the detachment of enveloped viruses from infected cells. The primate lentiviruses have evolved different countermeasures to tetherin. The majority of SIVs use Nef to antagonize the tetherin proteins of their nonhuman primate hosts. However, due to the absence of sequences in human tetherin required for antagonism by Nef, HIV-1 Vpu and HIV-2 Env evolved to serve this function in humans. We recently identified compensatory changes in the Env cytoplasmic domain of a pathogenic nef-deleted SIV that confers resistance to rhesus macaque tetherin. These observations highlight the extraordinary plasticity of the primate lentiviruses in adapting to the tetherin proteins of their respective hosts, and reveal a prominent role for tetherin in shaping the evolution of the primate lentiviruses.

  10. Chikungunya virus 3' untranslated region: adaptation to mosquitoes and a population bottleneck as major evolutionary forces.

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    Rubing Chen

    Full Text Available The 3' untranslated genome region (UTR of arthropod-borne viruses is characterized by enriched direct repeats (DRs and stem-loop structures. Despite many years of theoretical and experimental study, on-going positive selection on the 3'UTR had never been observed in 'real-time,' and the role of the arbovirus 3'UTR remains poorly understood. We observed a lineage-specific 3'UTR sequence pattern in all available Asian lineage of the mosquito-borne alphavirus, chikungunya virus (CHIKV (1958-2009, including complicated mutation and duplication patterns of the long DRs. Given that a longer genome is usually associated with less efficient replication, we hypothesized that the fixation of these genetic changes in the Asian lineage 3'UTR was due to their beneficial effects on adaptation to vectors or hosts. Using reverse genetic methods, we examined the functional importance of each direct repeat. Our results suggest that adaptation to mosquitoes, rather than to mammalian hosts, is a major evolutionary force on the CHIKV 3'UTR. Surprisingly, the Asian 3'UTR appeared to be inferior to its predicted ancestral sequence for replication in both mammals and mosquitoes, suggesting that its fixation in Asia was not a result of directional selection. Rather, it may have resulted from a population bottleneck during its introduction from Africa to Asia. We propose that this introduction of a 3'UTR with deletions led to genetic drift and compensatory mutations associated with the loss of structural/functional constraints, followed by two independent beneficial duplications and fixation due to positive selection. Our results provide further evidence that the limited epidemic potential of the Asian CHIKV strains resulted from founder effects that reduced its fitness for efficient transmission by mosquitoes there.

  11. Adaptation of influenza A viruses to cells expressing low levels of sialic acid leads to loss of neuraminidase activity.

    Science.gov (United States)

    Hughes, M T; McGregor, M; Suzuki, T; Suzuki, Y; Kawaoka, Y

    2001-04-01

    Influenza A viruses possess two virion surface proteins, hemagglutinin (HA) and neuraminidase (NA). The HA binds to sialyloligosaccharide viral receptors, while the NA removes sialic acids from the host cell and viral sialyloligosaccarides. Alterations of the HA occur during adaptation of influenza viruses to new host species, as in the 1957 and 1968 influenza pandemics. To gain a better understanding of the contributions of the HA and possibly the NA to this process, we generated cell lines expressing reduced levels of the influenza virus receptor determinant, sialic acid, by selecting Madin-Darby canine kidney cells resistant to a lectin specific for sialic acid linked to galactose by alpha(2-3) or alpha(2-6) linkages. One of these cell lines had less than 1/10 as much N-acetylneuraminic acid as its parent cell line. When serially passaged in this cell line, human H3N2 viruses lost sialidase activity due to a large internal deletion in the NA gene, without alteration of the HA gene. These findings indicate that NA mutations can contribute to the adaptation of influenza A virus to new host environments and hence may play a role in the transmission of virus across species.

  12. Innate and adaptive immune responses to in utero infection with bovine viral diarrhea virus.

    Science.gov (United States)

    Hansen, Thomas R; Smirnova, Natalia P; Webb, Brett T; Bielefeldt-Ohmann, Helle; Sacco, Randy E; Van Campen, Hana

    2015-06-01

    Infection of pregnant cows with noncytopathic (ncp) bovine viral diarrhea virus (BVDV) induces rapid innate and adaptive immune responses, resulting in clearance of the virus in less than 3 weeks. Seven to 14 days after inoculation of the cow, ncpBVDV crosses the placenta and induces a fetal viremia. Establishment of persistent infection with ncpBVDV in the fetus has been attributed to the inability to mount an immune response before 90-150 days of gestational age. The result is 'immune tolerance', persistent viral replication and shedding of ncpBVDV. In contrast, we describe the chronic upregulation of fetal Type I interferon (IFN) pathway genes and the induction of IFN-γ pathways in fetuses of cows infected on day 75 of gestation. Persistently infected (PI) fetal IFN-γ concentrations also increased at day 97 at the peak of fetal viremia and IFN-γ mRNA was significantly elevated in fetal thymus, liver and spleen 14-22 days post maternal inoculation. PI fetuses respond to ncpBVDV infection through induction of Type I IFN and IFN-γ activated genes leading to a reduction in ncpBVDV titer. We hypothesize that fetal infection with BVDV persists because of impaired induction of IFN-γ in the face of activated Type I IFN responses. Clarification of the mechanisms involved in the IFN-associated pathways during BVDV fetal infection may lead to better detection methods, antiviral compounds and selection of genetically resistant breeding animals.

  13. The Role of Plasmacytoid Dendritic Cells in Innate and Adaptive Immune Responses against Alpha Herpes Virus Infections

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    Philipp Schuster

    2011-01-01

    Full Text Available In 1999, two independent groups identified plasmacytoid dendritic cells (PDC as major type I interferon- (IFN- producing cells in the blood. Since then, evidence is accumulating that PDC are a multifunctional cell population effectively coordinating innate and adaptive immune responses. This paper focuses on the role of different immune cells and their interactions in the surveillance of alpha herpes virus infections, summarizes current knowledge on PDC surface receptors and their role in direct cell-cell contacts, and develops a risk factor model for the clinical implications of herpes simplex and varicella zoster virus reactivation. Data from studies involving knockout mice and cell-depletion experiments as well as human studies converge into a “spider web”, in which the direct and indirect crosstalk between many cell populations tightly controls acute, latent, and recurrent alpha herpes virus infections. Notably, cells involved in innate immune regulations appear to shape adaptive immune responses more extensively than previously thought.

  14. Effects of egg-adaptation on receptor-binding and antigenic properties of recent influenza A (H3N2) vaccine viruses.

    Science.gov (United States)

    Parker, Lauren; Wharton, Stephen A; Martin, Stephen R; Cross, Karen; Lin, Yipu; Liu, Yan; Feizi, Ten; Daniels, Rodney S; McCauley, John W

    2016-06-01

    Influenza A virus (subtype H3N2) causes seasonal human influenza and is included as a component of influenza vaccines. The majority of vaccine viruses are isolated and propagated in eggs, which commonly results in amino acid substitutions in the haemagglutinin (HA) glycoprotein. These substitutions can affect virus receptor-binding and alter virus antigenicity, thereby, obfuscating the choice of egg-propagated viruses for development into candidate vaccine viruses. To evaluate the effects of egg-adaptive substitutions seen in H3N2 vaccine viruses on sialic acid receptor-binding, we carried out quantitative measurement of virus receptor-binding using surface biolayer interferometry with haemagglutination inhibition (HI) assays to correlate changes in receptor avidity with antigenic properties. Included in these studies was a panel of H3N2 viruses generated by reverse genetics containing substitutions seen in recent egg-propagated vaccine viruses and corresponding cell culture-propagated wild-type viruses. These assays provide a quantitative approach to investigating the importance of individual amino acid substitutions in influenza receptor-binding. Results show that viruses with egg-adaptive HA substitutions R156Q, S219Y, and I226N, have increased binding avidity to α2,3-linked receptor-analogues and decreased binding avidity to α2,6-linked receptor-analogues. No measurable binding was detected for the viruses with amino acid substitution combination 156Q+219Y and receptor-binding increased in viruses where egg-adaptation mutations were introduced into cell culture-propagated virus. Substitutions at positions 156 and 190 appeared to be primarily responsible for low reactivity in HI assays with post-infection ferret antisera raised against 2012-2013 season H3N2 viruses. Egg-adaptive substitutions at position 186 caused substantial differences in binding avidity with an insignificant effect on antigenicity.

  15. Inhibition of Translation Initiation by Protein 169: A Vaccinia Virus Strategy to Suppress Innate and Adaptive Immunity and Alter Virus Virulence.

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    Pavla Strnadova

    2015-09-01

    Full Text Available Vaccinia virus (VACV is the prototypic orthopoxvirus and the vaccine used to eradicate smallpox. Here we show that VACV strain Western Reserve protein 169 is a cytoplasmic polypeptide expressed early during infection that is excluded from virus factories and inhibits the initiation of cap-dependent and cap-independent translation. Ectopic expression of protein 169 causes the accumulation of 80S ribosomes, a reduction of polysomes, and inhibition of protein expression deriving from activation of multiple innate immune signaling pathways. A virus lacking 169 (vΔ169 replicates and spreads normally in cell culture but is more virulent than parental and revertant control viruses in intranasal and intradermal murine models of infection. Intranasal infection by vΔ169 caused increased pro-inflammatory cytokines and chemokines, infiltration of pulmonary leukocytes, and lung weight. These alterations in innate immunity resulted in a stronger CD8+ T-cell memory response and better protection against virus challenge. This work illustrates how inhibition of host protein synthesis can be a strategy for virus suppression of innate and adaptive immunity.

  16. Molecular monitoring of African swine fever virus using surveys targeted at adult Ornithodoros ticks : a re-evaluation of Mkuze Game Reserve, South Africa

    Directory of Open Access Journals (Sweden)

    L.F. Arnot

    2009-09-01

    Full Text Available The Mkuze Game Reserve (MGR, in north-eastern KwaZulu-Natal Province, South Africa is an African swine fever virus (ASF controlled area. In a survey conducted in 1978, ASF prevalence in warthogs and Ornithodoros ticks in MGR was determined to be 2 % and 0.06 %, respectively. These values, acknowledged as being unusually low compared to other East and southern African ASF-positive sylvatic-cycle host populations, have not been assessed since. The availability of a sensitive PCR-based virus detection method, developed specifically for the sylvatic tampan host, prompted a re-evaluation of ASF virus (ASFV prevalence in MGR ticks. Of the 98 warthog burrows inspected for Ornithodoros presence, 59 (60.2 % were found to contain tampans and tick sampling was significantly male-biased. Whilst gender sampling-bias is not unusual, the 27 % increase in infestation rate of warthog burrows since the 1978 survey is noteworthy as it anticipates a concomitant increase in ASFV prevalence, particularly in light of the high proportion (75 % of adult ticks sampled. However, despite DNA integrity being confirmed by internal control amplification of the host 16S gene, PCR screening failed to detect ASFV. These results suggest that ASFV has either disappeared from MGR or if present, is localized, occurring at exceptionally low levels. Further extensive surveys are required to establish the ASFV status of sylvatic hosts in this controlled area.

  17. Why mosaic? Gene expression profiling of African cassava mosaic virus-infected cassava reveals the effect of chlorophyll degradation on symptom development.

    Science.gov (United States)

    Liu, Jiao; Yang, Jun; Bi, Huiping; Zhang, Peng

    2014-02-01

    Cassava mosaic disease, caused by cassava begomoviruses, is the most serious disease for cassava in Africa. However, the pathogenesis of this disease is poorly understood. We employed high throughput digital gene expression profiling based on the Illumina Solexa sequencing technology to investigate the global transcriptional response of cassava to African cassava mosaic virus infection. We found that 3,210 genes were differentially expressed in virus-infected cassava leaves. Gene ontology term and Kyoto Encyclopedia of Genes and Genomes pathway analysis indicated that genes implicated in photosynthesis were most affected, consistent with the chlorotic symptoms observed in infected leaves. The upregulation of chlorophyll degradation genes, including the genes encoding chlorophyllase, pheophytinase, and pheophorbide a oxygenase, and downregulation of genes encoding the major apoproteins in light-harvesting complex II were confirmed by qRT-PCR. These findings, together with the reduction of chlorophyll b content and fewer grana stacks in the infected leaf cells, reveal that the degradation of chlorophyll plays an important role in African cassava mosaic virus symptom development. This study will provide a road map for future investigations into viral pathogenesis.

  18. Genetically edited pigs lacking CD163 show no resistance following infection with the African swine fever virus isolate, Georgia 2007/1.

    Science.gov (United States)

    Popescu, Luca; Gaudreault, Natasha N; Whitworth, Kristen M; Murgia, Maria V; Nietfeld, Jerome C; Mileham, Alan; Samuel, Melissa; Wells, Kevin D; Prather, Randall S; Rowland, Raymond R R

    2017-01-15

    African swine fever is a highly contagious, often fatal disease of swine for which there is no vaccine or other curative treatment. The macrophage marker, CD163, is a putative receptor for African swine fever virus (ASFV). Pigs possessing a complete knockout of CD163 on macrophages were inoculated with Georgia 2007/1, a genotype 2 isolate. Knockout and wild type pen mates became infected and showed no differences in clinical signs, mortality, pathology or viremia. There was also no difference following in vitro infection of macrophages. The results do not rule out the possibility that other ASFV strains utilize CD163, but demonstrate that CD163 is not necessary for infection with the Georgia 2007/1 isolate. This work rules out a significant role for CD163 in ASFV infection and creates opportunities to focus on alternative receptors and entry mechanisms.

  19. First Report of the East-Central South African Genotype of Chikungunya Virus in Rio de Janeiro, Brazil

    Science.gov (United States)

    Souza, Thiara Manuele Alves; Azeredo, Elzinandes Leal; Badolato-Corrêa, Jessica; Damasco, Paulo Vieira; Santos, Carla; Petitinga-Paiva, Fabienne; Nunes, Priscila Conrado Guerra; Barbosa, Luciana Santos; Cipitelli, Márcio Costa; Chouin-Carneiro, Thais; Faria, Nieli Rodrigues Costa; Nogueira, Rita Maria Ribeiro; de Bruycker-Nogueira, Fernanda; dos Santos, Flavia Barreto

    2017-01-01

    Background: Chikungunya virus (CHIKV) is an arbovirus that causes an acute febrile syndrome with a severe and debilitating arthralgia. In Brazil, the Asian and East-Central South African (ECSA) genotypes are circulating in the north and northeast of the country, respectively. In 2015, the first autochthonous cases in Rio de Janeiro, Brazil were reported but until now the circulating strains have not been characterized. Therefore, we aimed here to perform the molecular characterization and phylogenetic analysis of CHIKV strains circulating in the 2016 outbreak occurred in the municipality of Rio de Janeiro. Methods: The cases analyzed in this study were collected at a private Hospital, from April 2016 to May 2016, during the chikungunya outbreak in Rio de Janeiro, Brazil. All cases were submitted to the Real Time RT-PCR for CHIKV genome detection and to anti-CHIKV IgM ELISA. Chikungunya infection was laboratorially confirmed by at least one diagnostic method and, randomly selected positive cases (n=10), were partially sequenced (CHIKV E1 gene) and analyzed. Results: The results showed that all the samples grouped in ECSA genotype branch and the molecular characterization of the fragment did not reveal the A226V mutation in the Rio de Janeiro strains analyzed, but a K211T amino acid substitution was observed for the first time in all samples and a V156A substitution in two of ten samples. Conclusions: Phylogenetic analysis and molecular characterization reveals the circulation of the ECSA genotype of CHIKV in the city of Rio de Janeiro, Brazil and two amino acids substitutions (K211T and V156A) exclusive to the CHIKV strains obtained during the 2016 epidemic, were reported. PMID:28286701

  20. Global health security: the wider lessons from the west African Ebola virus disease epidemic.

    Science.gov (United States)

    Heymann, David L; Chen, Lincoln; Takemi, Keizo; Fidler, David P; Tappero, Jordan W; Thomas, Mathew J; Kenyon, Thomas A; Frieden, Thomas R; Yach, Derek; Nishtar, Sania; Kalache, Alex; Olliaro, Piero L; Horby, Peter; Torreele, Els; Gostin, Lawrence O; Ndomondo-Sigonda, Margareth; Carpenter, Daniel; Rushton, Simon; Lillywhite, Louis; Devkota, Bhimsen; Koser, Khalid; Yates, Rob; Dhillon, Ranu S; Rannan-Eliya, Ravi P

    2015-05-09

    The Ebola virus disease outbreak in West Africa was unprecedented in both its scale and impact. Out of this human calamity has come renewed attention to global health security--its definition, meaning, and the practical implications for programmes and policy. For example, how does a government begin to strengthen its core public health capacities, as demanded by the International Health Regulations? What counts as a global health security concern? In the context of the governance of global health, including WHO reform, it will be important to distil lessons learned from the Ebola outbreak. The Lancet invited a group of respected global health practitioners to reflect on these lessons, to explore the idea of global health security, and to offer suggestions for next steps. Their contributions describe some of the major threats to individual and collective human health, as well as the values and recommendations that should be considered to counteract such threats in the future. Many different perspectives are proposed. Their common goal is a more sustainable and resilient society for human health and wellbeing.

  1. Within-host co-evolution of chronic viruses and the adaptive immune system

    Science.gov (United States)

    Nourmohammad, Armita

    We normally think of evolution occurring in a population of organisms, in response to their external environment. Rapid evolution of cellular populations also occurs within our bodies, as the adaptive immune system works to eliminate infection. Some pathogens, such as HIV, are able to persist in a host for extended periods of time, during which they also evolve to evade the immune response. In this talk I will introduce an analytical framework for the rapid co-evolution of B-cell and viral populations, based on the molecular interactions between them. Since the co-evolution of antibodies and viruses is perpetually out of equilibrium, I will show how to quantify the amount of adaptation in each of the two populations by analysis of their co-evolutionary history. I will discuss the consequences of competition between lineages of antibodies, and characterize the fate of a given lineage dependent on the state of the antibody and viral populations. In particular, I will discuss the conditions for emergence of highly potent broadly neutralizing antibodies, which are now recognized as critical for designing an effective vaccine against HIV.

  2. The RXL motif of the African cassava mosaic virus Rep protein is necessary for rereplication of yeast DNA and viral infection in plants

    Energy Technology Data Exchange (ETDEWEB)

    Hipp, Katharina; Rau, Peter; Schäfer, Benjamin [Institut für Biomaterialien und biomolekulare Systeme, Abteilung für Molekularbiologie und Virologie der Pflanzen, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart (Germany); Gronenborn, Bruno [Institut des Sciences du Végétal, CNRS, 91198 Gif-sur-Yvette (France); Jeske, Holger, E-mail: holger.jeske@bio.uni-stuttgart.de [Institut für Biomaterialien und biomolekulare Systeme, Abteilung für Molekularbiologie und Virologie der Pflanzen, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart (Germany)

    2014-08-15

    Geminiviruses, single-stranded DNA plant viruses, encode a replication-initiator protein (Rep) that is indispensable for virus replication. A potential cyclin interaction motif (RXL) in the sequence of African cassava mosaic virus Rep may be an alternative link to cell cycle controls to the known interaction with plant homologs of retinoblastoma protein (pRBR). Mutation of this motif abrogated rereplication in fission yeast induced by expression of wildtype Rep suggesting that Rep interacts via its RXL motif with one or several yeast proteins. The RXL motif is essential for viral infection of Nicotiana benthamiana plants, since mutation of this motif in infectious clones prevented any symptomatic infection. The cell-cycle link (Clink) protein of a nanovirus (faba bean necrotic yellows virus) was investigated that activates the cell cycle by binding via its LXCXE motif to pRBR. Expression of wildtype Clink and a Clink mutant deficient in pRBR-binding did not trigger rereplication in fission yeast. - Highlights: • A potential cyclin interaction motif is conserved in geminivirus Rep proteins. • In ACMV Rep, this motif (RXL) is essential for rereplication of fission yeast DNA. • Mutating RXL abrogated viral infection completely in Nicotiana benthamiana. • Expression of a nanovirus Clink protein in yeast did not induce rereplication. • Plant viruses may have evolved multiple routes to exploit host DNA synthesis.

  3. Inhibition of Lassa virus glycoprotein cleavage and multicycle replication by site 1 protease-adapted alpha(1-antitrypsin variants.

    Directory of Open Access Journals (Sweden)

    Anna Maisa

    Full Text Available BACKGROUND: Proteolytic processing of the Lassa virus envelope glycoprotein precursor GP-C by the host proprotein convertase site 1 protease (S1P is a prerequisite for the incorporation of the subunits GP-1 and GP-2 into viral particles and, hence, essential for infectivity and virus spread. Therefore, we tested in this study the concept of using S1P as a target to block efficient virus replication. METHODOLOGY/PRINCIPAL FINDING: We demonstrate that stable cell lines inducibly expressing S1P-adapted alpha(1-antitrypsin variants inhibit the proteolytic maturation of GP-C. Introduction of the S1P recognition motifs RRIL and RRLL into the reactive center loop of alpha(1-antitrypsin resulted in abrogation of GP-C processing by endogenous S1P to a similar level observed in S1P-deficient cells. Moreover, S1P-specific alpha(1-antitrypsins significantly inhibited replication and spread of a replication-competent recombinant vesicular stomatitis virus expressing the Lassa virus glycoprotein GP as well as authentic Lassa virus. Inhibition of viral replication correlated with the ability of the different alpha(1-antitrypsin variants to inhibit the processing of the Lassa virus glycoprotein precursor. CONCLUSIONS/SIGNIFICANCE: Our data suggest that glycoprotein cleavage by S1P is a promising target for the development of novel anti-arenaviral strategies.

  4. 非洲猪瘟病毒VP73蛋白的B细胞表位预测%The Prediction of B Cell Epitopes for VP73 Protein of African Fever Virus

    Institute of Scientific and Technical Information of China (English)

    李倩; 姚淑霞

    2008-01-01

    [Objective]The B cell epitopes for VP73 protein of African swine fever virus was predicted.[Method]Based on the analysis of the amino acid sequence and the flexible regions of VP73 protein,the B cell epitopes for VP73 protein of African swine fever virus were predicted by method of Kyte-Doolitfle,Emini and Jameson-Wolf.[Result]The B cell epitopes were located at or adjacent to the N-terminal No.11-18,26-48,73-82,136-150,159-174,181-189,191-210,247-276,279-295,313-323 and 382-392.[Conclusion]The multi-parameters analytic method was adopted to predict the B cell epitopes for VP73 protein of African swine fever virus,which laid solid foundation for further characterizing the protein of VP73 and researching epitope vaccine.

  5. Clinical and virologic response to episodic acyclovir for genital ulcers among HIV-1 seronegative, herpes simplex virus type 2 seropositive African women: a randomized, placebo-controlled trial.

    Science.gov (United States)

    Baeten, Jared M; Reid, Stewart E; Delany-Moretlwe, Sinead; Hughes, James P; Wang, Richard S; Wilcox, Ellen; Limbada, Mohammed; Akpomiemie, Godspower; Corey, Lawrence; Wald, Anna; Celum, Connie

    2012-01-01

    In a randomized trial among African women with recurrent genital herpes, episodic acyclovir therapy resulted in modestly greater likelihood of lesion healing (hazard ratio [HR] = 1.48, P = 0.098; mean, 5.1 vs. 6.0 days) and cessation of herpes simplex virus shedding (HR = 1.88, P = 0.008; mean, 3.0 vs. 5.0 days) compared with placebo, similar to results of studies in high-income countries (ClinicalTrials.gov registration NCT00808405).

  6. Synergistic Effect of S224P and N383D Substitutions in the PA of H5N1 Avian Influenza Virus Contributes to Mammalian Adaptation.

    Science.gov (United States)

    Song, Jiasheng; Xu, Jing; Shi, Jianzhong; Li, Yanbing; Chen, Hualan

    2015-05-22

    The adaptation of H5N1 avian influenza viruses to human poses a great threat to public health. Previous studies indicate the adaptive mutations in viral polymerase of avian influenza viruses are major contributors in overcoming the host species barrier, with the majority of mammalian adaptive mutations occurring in the PB2 protein. However, the adaptive mutations in the PA protein of the H5N1 avian influenza virus are less defined and poorly understood. In this study, we identified the synergistic effect of the PA/224P + 383D of H5N1 avian influenza viruses and its ability to enhance the pathogenicity and viral replication in a mammalian mouse model. Interestingly, the signature of PA/224P + 383D mainly exists in mammalian isolates of the H5N1 influenza virus and pdmH1N1 influenza virus, providing a potential pathway for the natural adaptation to mammals which imply the effects of natural adaptation to mammals. Notably, the mutation of PA/383D, which is highly conserved in avian influenza viruses, increases the polymerase activity in both avian and human cells, and may have roles in maintaining the avian influenza virus in their avian reservoirs, and jumping species to infect humans.

  7. A Novel Strategy to Increase Identification of African-Born People With Chronic Hepatitis B Virus Infection in the Chicago Metropolitan Area, 2012–2014

    Science.gov (United States)

    Song, Sharon; Johnson, Matthew; Harris, Aaron M.; Kaufman, Gary I.; Freedman, David; Quinn, Michael T.; Kim, Karen E.

    2016-01-01

    Introduction Most research on hepatitis B virus (HBV) infection in the United States is limited to Asian populations, despite an equally high prevalence among African immigrants. The purpose of this study was to determine testing and detection rates of HBV infection among African-born people residing in the Chicago metropolitan area. Methods A hepatitis education and prevention program was developed in collaboration with academic, clinical, and community partners for immigrant and refugee populations at risk for HBV infection. Community health workers implemented chain referral sampling, a novel strategy for recruiting hard-to-reach participants, targeting African-born participants. Participants were tested in both clinical and nonclinical settings. To assess infection status, blood samples were obtained for hepatitis B surface antigen (HBsAg), core antibody, and surface antibody testing. Demographic information was collected on age, sex, health insurance status, country of origin, and years residing in the United States. Participants were notified of testing results, and HBsAg-positive participants were referred for follow-up medical care. Results Of 1,000 African-born people who received education, 445 (45%) agreed to participate in HBV screening. There were 386 (87%) participants tested in clinical and 59 (13%) tested in nonclinical sites. Compared with participants who were tested in clinical settings, participants tested in nonclinical settings were older, were less likely to have health insurance, and had lived in the United States longer (P Somalia (11%), or Ethiopia (10%). There were 35 (8%) HBsAg-positive people, 37% had evidence of past infection, and 29% were immune. Conclusions Chain referral sampling identified many at-risk African-born people with chronic HBV infection. The large proportion of HBsAg-positive people in this sample reinforces the need for health promotion programs that are culturally appropriate and community-driven. PMID:27584874

  8. Adaptation and Study of AIDS Viruses in Animal and Cell Culture Systems

    Science.gov (United States)

    1989-01-30

    category one, e.g , Friend Murine -6- Leukemia Virus (FMuLV), Feline Leukemia Virus (FeLV), and the Macaque Type D SAIDS retrovirus (SRV) have been...10). One other animal lentivirus, Feline Immunodeficiency Virus (FIV), has had some utility in the study of protective immunity and in screening...et al. (58) transplanted RNA mumps virus infected human HeLa cells, or RNA vesicular stomatitis virus-infected hamster BHK cells into nude mice

  9. Genomic and protein structural maps of adaptive evolution of human influenza A virus to increased virulence in the mouse.

    Directory of Open Access Journals (Sweden)

    Jihui Ping

    Full Text Available Adaptive evolution is characterized by positive and parallel, or repeated selection of mutations. Mouse adaptation of influenza A virus (IAV produces virulent mutants that demonstrate positive and parallel evolution of mutations in the hemagglutinin (HA receptor and non-structural protein 1 (NS1 interferon antagonist genes. We now present a genomic analysis of all 11 genes of 39 mouse adapted IAV variants from 10 replicate adaptation experiments. Mutations were mapped on the primary and structural maps of each protein and specific mutations were validated with respect to virulence, replication, and RNA polymerase activity. Mouse adapted (MA variants obtained after 12 or 20-21 serial infections acquired on average 5.8 and 7.9 nonsynonymous mutations per genome of 11 genes, respectively. Among a total of 115 nonsynonymous mutations, 51 demonstrated properties of natural selection including 27 parallel mutations. The greatest degree of parallel evolution occurred in the HA receptor and ribonucleocapsid components, polymerase subunits (PB1, PB2, PA and NP. Mutations occurred in host nuclear trafficking factor binding sites as well as sites of virus-virus protein subunit interaction for NP, NS1, HA and NA proteins. Adaptive regions included cap binding and endonuclease domains in the PB2 and PA polymerase subunits. Four mutations in NS1 resulted in loss of binding to the host cleavage and polyadenylation specificity factor (CPSF30 suggesting that a reduction in inhibition of host gene expression was being selected. The most prevalent mutations in PB2 and NP were shown to increase virulence but differed in their ability to enhance replication and demonstrated epistatic effects. Several positively selected RNA polymerase mutations demonstrated increased virulence associated with >300% enhanced polymerase activity. Adaptive mutations that control host range and virulence were identified by their repeated selection to comprise a defined model for

  10. Immunobiology of Ebola and Lassa virus infections.

    Science.gov (United States)

    Prescott, Joseph B; Marzi, Andrea; Safronetz, David; Robertson, Shelly J; Feldmann, Heinz; Best, Sonja M

    2017-03-01

    Two of the most important contemporary emerging viruses that affect human health in Africa are Ebola virus (EBOV) and Lassa virus (LASV). The 2013-2016 West African outbreak of EBOV was responsible for more than 11,000 deaths, primarily in Guinea, Sierra Leone and Liberia. LASV is constantly emerging in these and surrounding West African countries, with an estimate of more than 500,000 cases of Lassa fever, and approximately 5,000 deaths, annually. Both EBOV and LASV are zoonotic, and human infection often results in a severe haemorrhagic fever in both cases. However, the contribution of specific immune responses to disease differs between EBOV and LASV. This Review examines innate and adaptive immune responses to these viruses with the goal of delineating responses that are associated with protective versus pathogenic outcomes.

  11. High genetic diversity and adaptive potential of two simian hemorrhagic fever viruses in a wild primate population.

    Directory of Open Access Journals (Sweden)

    Adam L Bailey

    Full Text Available Key biological properties such as high genetic diversity and high evolutionary rate enhance the potential of certain RNA viruses to adapt and emerge. Identifying viruses with these properties in their natural hosts could dramatically improve disease forecasting and surveillance. Recently, we discovered two novel members of the viral family Arteriviridae: simian hemorrhagic fever virus (SHFV-krc1 and SHFV-krc2, infecting a single wild red colobus (Procolobus rufomitratus tephrosceles in Kibale National Park, Uganda. Nearly nothing is known about the biological properties of SHFVs in nature, although the SHFV type strain, SHFV-LVR, has caused devastating outbreaks of viral hemorrhagic fever in captive macaques. Here we detected SHFV-krc1 and SHFV-krc2 in 40% and 47% of 60 wild red colobus tested, respectively. We found viral loads in excess of 10(6-10(7 RNA copies per milliliter of blood plasma for each of these viruses. SHFV-krc1 and SHFV-krc2 also showed high genetic diversity at both the inter- and intra-host levels. Analyses of synonymous and non-synonymous nucleotide diversity across viral genomes revealed patterns suggestive of positive selection in SHFV open reading frames (ORF 5 (SHFV-krc2 only and 7 (SHFV-krc1 and SHFV-krc2. Thus, these viruses share several important properties with some of the most rapidly evolving, emergent RNA viruses.

  12. Replication and adaptive mutations of low pathogenic avian influenza viruses in tracheal organ cultures of different avian species.

    Directory of Open Access Journals (Sweden)

    Henning Petersen

    Full Text Available Transmission of avian influenza viruses (AIV between different avian species may require genome mutations that allow efficient virus replication in a new species and could increase virulence. To study the role of domestic poultry in the evolution of AIV we compared replication of low pathogenic (LP AIV of subtypes H9N2, H7N7 and H6N8 in tracheal organ cultures (TOC and primary embryo fibroblast cultures of chicken, turkey, Pekin duck and homing pigeon. Virus strain-dependent and avian species-related differences between LPAIV were observed in growth kinetics and induction of ciliostasis in TOC. In particular, our data demonstrate high susceptibility to LPAIV of turkey TOC contrasted with low susceptibility of homing pigeon TOC. Serial virus passages in the cells of heterologous host species resulted in adaptive mutations in the AIV genome, especially in the receptor-binding site and protease cleavage site of the hemagglutinin. Our data highlight differences in susceptibility of different birds to AIV viruses and emphasizes potential role of poultry in the emergence of new virus variants.

  13. Ns1 is a key protein in the vaccine composition to protect Ifnar(-/- mice against infection with multiple serotypes of African horse sickness virus.

    Directory of Open Access Journals (Sweden)

    Francisco de la Poza

    Full Text Available African horse sickness virus (AHSV belongs to the genus Orbivirus. We have now engineered naked DNAs and recombinant modified vaccinia virus Ankara (rMVA expressing VP2 and NS1 proteins from AHSV-4. IFNAR((-/- mice inoculated with DNA/rMVA-VP2,-NS1 from AHSV-4 in an heterologous prime-boost vaccination strategy generated significant levels of neutralizing antibodies specific of AHSV-4. In addition, vaccination stimulated specific T cell responses against the virus. The vaccine elicited partial protection against an homologous AHSV-4 infection and induced cross-protection against the heterologous AHSV-9. Similarly, IFNAR((-/- mice vaccinated with an homologous prime-boost strategy with rMVA-VP2-NS1 from AHSV-4 developed neutralizing antibodies and protective immunity against AHSV-4. Furthermore, the levels of immunity were very high since none of vaccinated animals presented viraemia when they were challenged against the homologous AHSV-4 and very low levels when they were challenged against the heterologous virus AHSV-9. These data suggest that the immunization with rMVA/rMVA was more efficient in protection against a virulent challenge with AHSV-4 and both strategies, DNA/rMVA and rMVA/rMVA, protected against the infection with AHSV-9. The inclusion of the protein NS1 in the vaccine formulations targeting AHSV generates promising multiserotype vaccines.

  14. Development and validation of a multiplex, real-time RT PCR assay for the simultaneous detection of classical and African swine fever viruses.

    Science.gov (United States)

    Haines, Felicity J; Hofmann, Martin A; King, Donald P; Drew, Trevor W; Crooke, Helen R

    2013-01-01

    A single-step, multiplex, real-time polymerase chain reaction (RT-PCR) was developed for the simultaneous and differential laboratory diagnosis of Classical swine fever virus (CSFV) and African swine fever virus (ASFV) alongside an exogenous internal control RNA (IC-RNA). Combining a single extraction methodology and primer and probe sets for detection of the three target nucleic acids CSFV, ASFV and IC-RNA, had no effect on the analytical sensitivity of the assay and the new triplex RT-PCR was comparable to standard PCR techniques for CSFV and ASFV diagnosis. After optimisation the assay had a detection limit of 5 CSFV genome copies and 22 ASFV genome copies. Analytical specificity of the triplex assay was validated using a panel of viruses representing 9 of the 11 CSFV subgenotypes, at least 8 of the 22 ASFV genotypes as well as non-CSFV pestiviruses. Positive and negative clinical samples from animals infected experimentally, due to field exposure or collected from the UK which is free from both swine diseases, were used to evaluate the diagnostic sensitivity and specificity for detection of both viruses. The diagnostic sensitivity was 100% for both viruses whilst diagnostic specificity estimates were 100% for CSFV detection and 97.3% for ASFV detection. The inclusion of a heterologous internal control allowed identification of false negative results, which occurred at a higher level than expected. The triplex assay described here offers a valuable new tool for the differential detection of the causative viruses of two clinically indistinguishable porcine diseases, whose geographical occurrence is increasingly overlapping.

  15. Development and validation of a multiplex, real-time RT PCR assay for the simultaneous detection of classical and African swine fever viruses.

    Directory of Open Access Journals (Sweden)

    Felicity J Haines

    Full Text Available A single-step, multiplex, real-time polymerase chain reaction (RT-PCR was developed for the simultaneous and differential laboratory diagnosis of Classical swine fever virus (CSFV and African swine fever virus (ASFV alongside an exogenous internal control RNA (IC-RNA. Combining a single extraction methodology and primer and probe sets for detection of the three target nucleic acids CSFV, ASFV and IC-RNA, had no effect on the analytical sensitivity of the assay and the new triplex RT-PCR was comparable to standard PCR techniques for CSFV and ASFV diagnosis. After optimisation the assay had a detection limit of 5 CSFV genome copies and 22 ASFV genome copies. Analytical specificity of the triplex assay was validated using a panel of viruses representing 9 of the 11 CSFV subgenotypes, at least 8 of the 22 ASFV genotypes as well as non-CSFV pestiviruses. Positive and negative clinical samples from animals infected experimentally, due to field exposure or collected from the UK which is free from both swine diseases, were used to evaluate the diagnostic sensitivity and specificity for detection of both viruses. The diagnostic sensitivity was 100% for both viruses whilst diagnostic specificity estimates were 100% for CSFV detection and 97.3% for ASFV detection. The inclusion of a heterologous internal control allowed identification of false negative results, which occurred at a higher level than expected. The triplex assay described here offers a valuable new tool for the differential detection of the causative viruses of two clinically indistinguishable porcine diseases, whose geographical occurrence is increasingly overlapping.

  16. Comparative analysis of the complete genome sequences of Kenyan African swine fever virus isolates within p72 genotypes IX and X.

    Science.gov (United States)

    Bishop, Richard P; Fleischauer, Clare; de Villiers, Etienne P; Okoth, Edward A; Arias, Marisa; Gallardo, Carmina; Upton, Chris

    2015-04-01

    Twelve complete African swine fever virus (ASFV) genome sequences are currently publicly available and these include only one sequence from East Africa. We describe genome sequencing and annotation of a recent pig-derived p72 genotype IX, and a tick-derived genotype X isolate from Kenya using the Illumina platform and comparison with the Kenya 1950 isolate. The three genomes constitute a cluster that was phylogenetically distinct from other ASFV genomes, but 98-99 % conserved within the group. Vector-based compositional analysis of the complete genomes produced a similar topology. Of the 125 previously identified 'core' ASFV genes, two ORFs of unassigned function were absent from the genotype IX sequence which was 184 kb in size as compared to 191 kb for the genotype X. There were multiple differences among East African genomes in the 360 and 110 multicopy gene families. The gene corresponding to 360-19R has transposed to the 5' variable region in both genotype X isolates. Additionally, there is a 110 ORF in the tick-derived genotype X isolate formed by fusion of 13L and 14L that is unique among ASFV genomes. In future, functional analysis based on the variations in the multicopy families may reveal whether they contribute to the observed differences in virulence between genotpye IX and X viruses.

  17. Stoichiometry of monoclonal antibody neutralization of T-cell line-adapted human immunodeficiency virus type 1

    DEFF Research Database (Denmark)

    Schønning, Kristian; Lund, O; Lund, O S;

    1999-01-01

    In order to study the stoichiometry of monoclonal antibody (MAb) neutralization of T-cell line-adapted human immunodeficiency virus type 1 (HIV-1) in antibody excess and under equilibrium conditions, we exploited the ability of HIV-1 to generate mixed oligomers when different env genes...... are coexpressed. By the coexpression of Env glycoproteins that either can or cannot bind a neutralizing MAb in an env transcomplementation assay, virions were generated in which the proportion of MAb binding sites could be regulated. As the proportion of MAb binding sites in Env chimeric virus increased, MAb...... neutralization gradually increased. Virus neutralization by virion aggregation was minimal, as MAb binding to HIV-1 Env did not interfere with an AMLV Env-mediated infection by HIV-1(AMLV/HIV-1) pseudotypes of CD4(-) HEK293 cells. MAb neutralization of chimeric virions could be described as a third...

  18. Vaccination with viral protein-mimicking peptides postpones mortality in domestic pigs infected by African swine fever virus.

    Science.gov (United States)

    Ivanov, Vadim; Efremov, Evgeniy E; Novikov, Boris V; Balyshev, Vladimir M; Tsibanov, Sodnom Zh; Kalinovsky, Tatiana; Kolbasov, Denis V; Niedzwiecki, Aleksandra; Rath, Matthias

    2011-01-01

    Periodic outbreaks of African swine fever virus (ASFV) infection around the world threaten local populations of domestic pigs with lethal disease and provide grounds for pandemic spread. Effective vaccination may bring this threat under control. We investigated the effectiveness of select peptides mimicking viral proteins in establishing a protective immune response. Forty-six synthetic peptides based on the analysis of the complete nucleotide sequence of ASFV were tested for immunogenicity in mice. The 17 best immune response-inducing peptide candidates were selected for further investigation. Twenty-four domestic pigs, 3-4 months old and weighing 20-25 kg, were divided into six groups (n = 4) and immunized by subcutaneous injection using a standard three-round injection protocol with one of four peptide combinations prepared from the 17 peptides (Groups 1-4) or with carrier only (Group 5). Group 6, the control, was not vaccinated. Animal body temperature and behavior were monitored during and post immunization for health assessment. Two weeks after the last round of immunizations, the pigs were infected with live ASFV (Espania 70) at 6.0 Ig GAE50/cm3, and the survival rate was monitored. Blood samples were collected for analysis the day before infection and on days 3, 7 and 10 post-infection, or from deceased animals. The serum titers of specific immunoglobulins against synthetic peptides and whole inactivated ASFV were determined by enzyme immunoassay before and after infection. The presence of viral DNA in blood serum samples was determined by polymerase chain reaction. Viral infection activity in blood sera was determined by heme absorption in cultured porcine bone marrow and porcine leukocyte cells. Repeating the injection of synthetic peptides in both the mice and pigs produced an immune response specific to individual peptides, which differed widely in the intensity scale. Specific anti-whole virus immunoglobulin binding activity in the swine serum samples

  19. Spatial structure and climatic adaptation in African maize revealed by surveying SNP diversity in relation to global breeding and landrace panels.

    Directory of Open Access Journals (Sweden)

    Ola T Westengen

    Full Text Available BACKGROUND: Climate change threatens maize productivity in sub-Saharan Africa. To ensure food security, access to locally adapted genetic resources and varieties is an important adaptation measure. Most of the maize grown in Africa is a genetic mix of varieties introduced at different historic times following the birth of the trans-Atlantic economy, and knowledge about geographic structure and local adaptations is limited. METHODOLOGY: A panel of 48 accessions of maize representing various introduction routes and sources of historic and recent germplasm introductions in Africa was genotyped with the MaizeSNP50 array. Spatial genetic structure and genetic relationships in the African panel were analysed separately and in the context of a panel of 265 inbred lines representing global breeding material (based on 26,900 SNPs and a panel of 1127 landraces from the Americas (270 SNPs. Environmental association analysis was used to detect SNPs associated with three climatic variables based on the full 43,963 SNP dataset. CONCLUSIONS: The genetic structure is consistent between subsets of the data and the markers are well suited for resolving relationships and admixture among the accessions. The African accessions are structured in three clusters reflecting historical and current patterns of gene flow from the New World and within Africa. The Sahelian cluster reflects original introductions of Meso-American landraces via Europe and a modern introduction of temperate breeding material. The Western cluster reflects introduction of Coastal Brazilian landraces, as well as a Northeast-West spread of maize through Arabic trade routes across the continent. The Eastern cluster most strongly reflects gene flow from modern introduced tropical varieties. Controlling for population history in a linear model, we identify 79 SNPs associated with maximum temperature during the growing season. The associations located in genes of known importance for abiotic stress

  20. ADAPTATION OF INDIGENOUS INFECTIOUS BURSAL DISEASE VIRUS (IBDV) IN EMBRYONATED CHICKEN EGGS

    OpenAIRE

    A. N. Ahmad, I. Hussain, M. Siddique and M. S. Mahmood

    2005-01-01

    Infectious bursal disease virus was isolated from bursae of broilers suffering from Gumboro disease and was designated as field virus (FV). The virus was confirmed through agar gel precipitation test (AGPT) and counter current immunoelectrophoresis (CCIE). The virus was titrated by using reverse passive haemagglutination (RPHA) test and egg infective dose fifty (EID50). The FV was inoculated into 9-to 11-day-old embryonated chicken eggs through chorio-allantoic membrane (CAM). At each passage...

  1. Pandemic influenza A viruses escape from restriction by human MxA through adaptive mutations in the nucleoprotein.

    Directory of Open Access Journals (Sweden)

    Benjamin Mänz

    2013-03-01

    Full Text Available The interferon-induced dynamin-like MxA GTPase restricts the replication of influenza A viruses. We identified adaptive mutations in the nucleoprotein (NP of pandemic strains A/Brevig Mission/1/1918 (1918 and A/Hamburg/4/2009 (pH1N1 that confer MxA resistance. These resistance-associated amino acids in NP differ between the two strains but form a similar discrete surface-exposed cluster in the body domain of NP, indicating that MxA resistance evolved independently. The 1918 cluster was conserved in all descendent strains of seasonal influenza viruses. Introduction of this cluster into the NP of the MxA-sensitive influenza virus A/Thailand/1(KAN-1/04 (H5N1 resulted in a gain of MxA resistance coupled with a decrease in viral replication fitness. Conversely, introduction of MxA-sensitive amino acids into pH1N1 NP enhanced viral growth in Mx-negative cells. We conclude that human MxA represents a barrier against zoonotic introduction of avian influenza viruses and that adaptive mutations in the viral NP should be carefully monitored.

  2. Adaptive and Challenged Parenting among African American Mothers: Parenting Profiles Relate to Head Start Children's Aggression and Hyperactivity

    Science.gov (United States)

    Carpenter, Johanna L.; Mendez, Julia

    2013-01-01

    Research Findings: This study used a within-group research design and person-centered analytic methods to identify multidimensional profiles of parenting styles, parenting practices, and related emotional factors in a sample of 274 African American mothers recruited from Head Start programs in the northeastern and southeastern United States.…

  3. Changes in adaptation of H5N2 highly pathogenic avian influenza H5 clade 2.3.4.4 viruses in chickens and mallards

    Science.gov (United States)

    H5N2 highly pathogenic avian influenza (HPAI) viruses caused a severe poultry outbreak in the United States (U.S.) during 2015. In order to examine changes in adaptation of this viral lineage, the infectivity, transmission and pathogenesis of poultry H5N2 viruses was investigated in chickens and mal...

  4. Bentho-pelagic divergence of cichlid feeding architecture was prodigious and consistent during multiple adaptive radiations within African rift-lakes.

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    W James Cooper

    Full Text Available BACKGROUND: How particular changes in functional morphology can repeatedly promote ecological diversification is an active area of evolutionary investigation. The African rift-lake cichlids offer a calibrated time series of the most dramatic adaptive radiations of vertebrate trophic morphology yet described, and the replicate nature of these events provides a unique opportunity to test whether common changes in functional morphology have repeatedly facilitated their ecological success. METHODOLOGY/PRINCIPAL FINDINGS: Specimens from 87 genera of cichlid fishes endemic to Lakes Tanganyka, Malawi and Victoria were dissected in order to examine the functional morphology of cichlid feeding. We quantified shape using geometric morphometrics and compared patterns of morphological diversity using a series of analytical tests. The primary axes of divergence were conserved among all three radiations, and the most prevalent changes involved the size of the preorbital region of the skull. Even the fishes from the youngest of these lakes (Victoria, which exhibit the lowest amount of skull shape disparity, have undergone extensive preorbital evolution relative to other craniofacial traits. Such changes have large effects on feeding biomechanics, and can promote expansion into a wide array of niches along a bentho-pelagic ecomorphological axis. CONCLUSIONS/SIGNIFICANCE: Here we show that specific changes in trophic anatomy have evolved repeatedly in the African rift lakes, and our results suggest that simple morphological alterations that have large ecological consequences are likely to constitute critical components of adaptive radiations in functional morphology. Such shifts may precede more complex shape changes as lineages diversify into unoccupied niches. The data presented here, combined with observations of other fish lineages, suggest that the preorbital region represents an evolutionary module that can respond quickly to natural selection when fishes

  5. ADAPTATION OF INDIGENOUS INFECTIOUS BURSAL DISEASE VIRUS (IBDV IN EMBRYONATED CHICKEN EGGS

    Directory of Open Access Journals (Sweden)

    A. N. Ahmad, I. Hussain, M. Siddique and M. S. Mahmood

    2005-04-01

    Full Text Available Infectious bursal disease virus was isolated from bursae of broilers suffering from Gumboro disease and was designated as field virus (FV. The virus was confirmed through agar gel precipitation test (AGPT and counter current immunoelectrophoresis (CCIE. The virus was titrated by using reverse passive haemagglutination (RPHA test and egg infective dose fifty (EID50. The FV was inoculated into 9-to 11-day-old embryonated chicken eggs through chorio-allantoic membrane (CAM. At each passage, the virus in the chorio-allantoic fluid (CAF and embryos was confirmed by AGPT and titrated by RPHA test. Geometric mean titer (GMT of the virus in CAF was 37 to 64 in 1-3rd passage, 111 to 239 in 4-7th passages. In 8 to 15th passages, virus titer remained from 294 to 588 and in 16-24th passages virus titer ranged from 675 to 2195. Similarly, virus titer in the embryos was 1024 to 512 in 1st -10th passages, while the virus titer in passages 11-24th ranged from 478 to 111. Embryos were monitored for lesions and mortality. Severe lesions were present on the CAM in 1st-7th passages, while moderate to mild haemorrhages were seen in 8th to 16th passages and in 17th _ 24th passages no lesions were observed.

  6. Distinct mutant hepatitis B virus genomes, with alterations in all four open reading frames, in a single South African hepatocellular carcinoma patient.

    Science.gov (United States)

    Skelton, Michelle; Kew, Michael C; Kramvis, Anna

    2012-01-01

    Sequence variation of hepatitis B virus (HBV) can influence the replication, antigen expression and pathogenicity of the virus. We report on the mutational analysis of HBV performed in a 28-year-old Black South African female diagnosed with HBV-induced hepatocellular carcinoma. Full-genome amplification and DNA sequencing of HBV was carried out. Five distinct complete genomic clones were described with extensive genomic and intragenic variation. Phylogenetic analysis revealed that all five clones belonged to subgenotype A1 and that there were at least four virus populations with genomes of different lengths ranging from 3194 to 3253 base pairs. In this particular patient, four major characteristic features, not previously reported to occur simultaneously in HBV isolated from a single patient, were observed. Firstly, all the clones harboured a 13 base pair deletion and a 45 base pair insertion in the basic core promoter (BCP). Secondly, a 37 base pair insertion in the core gene with three adjacent single nucleotide deletions were observed. Thirdly, premature S gene stop codons were observed in some clones and lastly X gene initiation codon mutations were also observed. The complex nature of the mutations in the HBV isolated from this single patient may have contributed to the early onset of hepatocarcinogenesis.

  7. Permissivity of primary human hepatocytes and different hepatoma cell lines to cell culture adapted hepatitis C virus.

    Directory of Open Access Journals (Sweden)

    Francois Helle

    Full Text Available Significant progress has been made in Hepatitis C virus (HCV culture since the JFH1 strain cloning. However, developing efficient and physiologically relevant culture systems for all viral genotypes remains an important goal. In this work, we aimed at producing a high titer JFH1 derived virus to test different hepatic cells' permissivity. To this end, we performed successive infections and obtained a JFH1 derived virus reaching high titers. Six potential adaptive mutations were identified (I599V in E2, R1373Q and M1611T in NS3, S2364P and C2441S in NS5A and R2523K in NS5B and the effect of these mutations on HCV replication and infectious particle production was investigated. This cell culture adapted virus enabled us to efficiently infect primary human hepatocytes, as demonstrated using the RFP-NLS-IPS reporter protein and intracellular HCV RNA quantification. However, the induction of a strong type III interferon response in these cells was responsible for HCV inhibition. The disruption of this innate immune response led to a strong infection enhancement and permitted the detection of viral protein expression by western blotting as well as progeny virus production. This cell culture adapted virus also enabled us to easily compare the permissivity of seven hepatoma cell lines. In particular, we demonstrated that HuH-7, HepG2-CD81, PLC/PRF/5 and Hep3B cells were permissive to HCV entry, replication and secretion even if the efficiency was very low in PLC/PRF/5 and Hep3B cells. In contrast, we did not observe any infection of SNU-182, SNU-398 and SNU-449 hepatoma cells. Using iodixanol density gradients, we also demonstrated that the density profiles of HCV particles produced by PLC/PRF/5 and Hep3B cells were different from that of HuH-7 and HepG2-CD81 derived virions. These results will help the development of a physiologically relevant culture system for HCV patient isolates.

  8. Agricultural Production, Land-use/cover Change and the Desertification Debate in the West African Savannah: An Adapted Political Ecology Approach

    Directory of Open Access Journals (Sweden)

    Peter Kojo Boateng

    2013-10-01

    Full Text Available In the semi-arid tropics of West Africa where farming is the major livelihood source, it is claimed that African farmers are degrading their land: first because of shifting cultivation, later because population growth brought about “over-cultivation” or farm expansion and the scattering of more farms on the landscape.  In response to these issues, West African governments have emphasised the need and rolled out programmes for modernisation of smallholder agriculture through promotion of capital-intensive and market-driven strategies. Implicit in this modernisation policy orientation is the idea that the way production is organised by peasants in the semi-arid environments have to change; meaning poor peasants, regarded as perpetuators of land degradation, who may not produce for the market need to be modernised in line with the state’s vision of agricultural development and environmental management. However, new perspectives being generated from several local level studies of agricultural production and land-use/cover change in the semi-arid savannah regions of West Africa offer departure points from those dominant narratives of increasing degradation and desertification. This paper discusses this emerging paradigmatic revolution by reviewing the literature on 3 highly polarised issues around land-use/cover change in the West African savannah – (a discourses of environmental degradation; (b human-environment interactions and agricultural production; and (c mapping of land cover changes in drylands. Within these reviews, the paper highlights ways it move beyond currently contrasting views, before advancing an adapted political ecology framework deemed suited for exploring the complex relationships between agricultural production and land-use/cover change.

  9. The soft palate is an important site of adaptation for transmissible influenza viruses.

    Science.gov (United States)

    Lakdawala, Seema S; Jayaraman, Akila; Halpin, Rebecca A; Lamirande, Elaine W; Shih, Angela R; Stockwell, Timothy B; Lin, Xudong; Simenauer, Ari; Hanson, Christopher T; Vogel, Leatrice; Paskel, Myeisha; Minai, Mahnaz; Moore, Ian; Orandle, Marlene; Das, Suman R; Wentworth, David E; Sasisekharan, Ram; Subbarao, Kanta

    2015-10-01

    Influenza A viruses pose a major public health threat by causing seasonal epidemics and sporadic pandemics. Their epidemiological success relies on airborne transmission from person to person; however, the viral properties governing airborne transmission of influenza A viruses are complex. Influenza A virus infection is mediated via binding of the viral haemagglutinin (HA) to terminally attached α2,3 or α2,6 sialic acids on cell surface glycoproteins. Human influenza A viruses preferentially bind α2,6-linked sialic acids whereas avian influenza A viruses bind α2,3-linked sialic acids on complex glycans on airway epithelial cells. Historically, influenza A viruses with preferential association with α2,3-linked sialic acids have not been transmitted efficiently by the airborne route in ferrets. Here we observe efficient airborne transmission of a 2009 pandemic H1N1 (H1N1pdm) virus (A/California/07/2009) engineered to preferentially bind α2,3-linked sialic acids. Airborne transmission was associated with rapid selection of virus with a change at a single HA site that conferred binding to long-chain α2,6-linked sialic acids, without loss of α2,3-linked sialic acid binding. The transmissible virus emerged in experimentally infected ferrets within 24 hours after infection and was remarkably enriched in the soft palate, where long-chain α2,6-linked sialic acids predominate on the nasopharyngeal surface. Notably, presence of long-chain α2,6-linked sialic acids is conserved in ferret, pig and human soft palate. Using a loss-of-function approach with this one virus, we demonstrate that the ferret soft palate, a tissue not normally sampled in animal models of influenza, rapidly selects for transmissible influenza A viruses with human receptor (α2,6-linked sialic acids) preference.

  10. Detection of African Swine Fever Virus DNA in Blood Samples Stored on FTA Cards from Asymptomatic Pigs in Mbeya Region, Tanzania

    DEFF Research Database (Denmark)

    Braae, U. C.; Johansen, M. V.; Ngowi, H. A.;

    2015-01-01

    The aim of the study was to assess whether blood samples collected onto FTA® cards could be used in combination with real-time PCR for the detection of African swine fever virus (ASFV) DNA in samples from resource-poor settings under the assumption that asymptomatically (sub-clinically) infected...... pigs may be present. Blood samples were collected from clinically healthy pigs from Mbeya Region, Tanzania. The blood samples were stored on FTA® cards and analysed by real-time PCR assays in duplicate; three pigs had high levels of viral DNA (Ct values of 27-29), and three pigs had a low level...... of viral DNA (Ct 36-45). Four pigs were positive in one of the duplicate samples only, but clear products of the expected size were obtained when the reactions were analysed by gel electrophoresis. For comparison, blood samples from pigs experimentally infected with either a pathogenic (OURT T88...

  11. Robust hepatitis C genotype 3a cell culture releasing adapted intergenotypic 3a/2a (S52/JFH1) viruses

    DEFF Research Database (Denmark)

    Gottwein, Judith; Scheel, Troels; Høgh, Mette;

    2007-01-01

    , which has a high prevalence worldwide. METHODS: Huh7.5 cells were transfected with RNA transcripts of an intergenotypic 3a/JFH1 recombinant with core, E1, E2, p7, and NS2 of the 3a reference strain S52, and released viruses were passaged. Cultures were examined for HCV core and/or NS5A expression...... (immunostaining), HCV RNA titers (real-time PCR), and infectivity titers (50% tissue culture infectious dose). The role of mutations identified by sequencing of recovered S52/JFH1 viruses was analyzed by reverse genetics studies. RESULTS: S52/JFH1 and J6/JFH viruses passaged in Huh7.5 cells showed comparable...... growth kinetics and similar peak HCV RNA and infectivity titers. However, analysis of S52/JFH1 viruses identified 9 putative adaptive mutations in core, E2, p7, NS3, and NS5A. All 7 S52/JFH1 recombinants with an amino acid change in p7 combined with a change in NS3 or NS5A, but only 2 of 9 recombinants...

  12. Development of a Microsphere-based Immunoassay for Serological Detection of African Horse Sickness Virus and Comparison with Other Diagnostic Techniques.

    Science.gov (United States)

    Sánchez-Matamoros, A; Beck, C; Kukielka, D; Lecollinet, S; Blaise-Boisseau, S; Garnier, A; Rueda, P; Zientara, S; Sánchez-Vizcaíno, J M

    2016-12-01

    African horse sickness (AHS) is a viral disease that causes high morbidity and mortality rates in susceptible Equidae and therefore significant economic losses. More rapid, sensitive and specific assays are required by diagnostic laboratories to support effective surveillance programmes. A novel microsphere-based immunoassay (Luminex assay) in which beads are coated with recombinant AHS virus (AHSV) structural protein 7 (VP7) has been developed for serological detection of antibodies against VP7 of any AHSV serotype. The performance of this assay was compared with that of a commercial enzyme-linked immunosorbent assay (ELISA) and commercial lateral flow assay (LFA) on a large panel of serum samples from uninfected horses (n = 92), from a reference library of all AHSV serotypes (n = 9), on samples from horses experimentally infected with AHSV (n = 114), and on samples from West African horses suspected of having AHS (n = 85). The Luminex assay gave the same negative results as ELISA when used to test the samples from uninfected horses. Both assays detected antibodies to all nine AHSV serotypes. In contrast, the Luminex assay detected a higher rate of anti-VP7 positivity in the West African field samples than did ELISA or LFA. The Luminex assay detected anti-VP7 positivity in experimentally infected horses at 7 days post-infection, compared to 13 days for ELISA. This novel immunoassay provides a platform for developing multiplex assays, in which the presence of antibodies against multiple ASHV antigens can be detected simultaneously. This would be useful for serotyping or for differentiating infected from vaccinated animals.

  13. Aspects of Innate and Adaptive Immune responses during Respiratory Syncytial Virus Infection

    NARCIS (Netherlands)

    Lukens, M.V.

    2009-01-01

    Respiratory Syncytial Virus (RSV) infections are a major cause of lower respiratory tract disease and represent a major disease burden in infants, immune compromised patients and the elderly. Despite the identification and isolation of the virus in 1956, extensive efforts since then to develop a saf

  14. Comparative evaluation of novel African swine fever virus (ASF) antibody detection techniques derived from specific ASF viral genotypes with the OIE internationally prescribed serological tests.

    Science.gov (United States)

    Gallardo, C; Soler, A; Nieto, R; Carrascosa, A L; De Mia, G M; Bishop, R P; Martins, C; Fasina, F O; Couacy-Hymman, E; Heath, L; Pelayo, V; Martín, E; Simón, A; Martín, R; Okurut, A R; Lekolol, I; Okoth, E; Arias, M

    2013-02-22

    The presence of antibodies against African swine fever (ASF), a complex fatal notifiable OIE disease of swine, is always indicative of previous infection, since there is no vaccine that is currently used in the field. The early appearance and subsequent long-term persistence of antibodies combined with cost-effectiveness make antibody detection techniques essential in control programmes. Recent reports appear to indicate that the serological tests recommended by the OIE for ASF monitoring are much less effective in East and Southern Africa where viral genetic and antigenic diversity is the greatest. We report herein an extensive analysis including more than 1000 field and experimental infection sera, in which the OIE recommended tests are compared with antigen-specific ELISAs and immuno-peroxidase staining of cells (IPT). The antibody detection results generated using new antigen-specific tests, developed in this study, which are based on production of antigen fractions generated by infection and virus purification from COS-1 cells, showed strong concordance with the OIE tests. We therefore conclude that the lack of success is not attributable to antigenic polymorphism and may be related to the specific characteristics of the local breeds African pigs.

  15. Inactivated and adjuvanted vaccine for the control of the African horse sickness virus serotype 9 infection: evaluation of efficacy in horses and guinea-pig model.

    Science.gov (United States)

    Lelli, Rossella; Molini, Umberto; Ronchi, Gaetano Federico; Rossi, Emanuela; Franchi, Paola; Ulisse, Simonetta; Armillotta, Gisella; Capista, Sara; Khaiseb, Siegfried; Di Ventura, Mauro; Pini, Attilio

    2013-01-01

    African horse sickness (AHS) is a non-contagious viral disease of solipeds transmitted by Culicoides. The disease is endemic in most African countries. Past experience has shown that Italy is a country exposed to emerging infectious diseases endemic to Africa; an incursion of AHS virus together with the widespread presence of Culicoides vectors could be the cause of a serious epidemic emergency. A live attenuated vaccine containing seven of the nine viral serotypes, serotype 5 and 9 are excluded, is commercially available from Onderstepoort Biological Products. However, the use of live vaccines is a matter of endless disputes, and therefore inactivated or recombinant alternative products have been investigated over the years. Since research on AHS is hampered by the use of horses to evaluate vaccine potency, in a previous experiment serological response to serotypes 5 and 9 was assayed in guinea-pigs and horses. A durable and comparable serological response was observed in the two animal species. In the present study antibody response in horses and guinea-pigs, immunised with the inactivated-adjuvanted vaccine formulated with serotype 9, was tested over a period of 12 months. When immunity was challenged, horses were protected from infection and disease. Antibody response in horses and guinea-pigs compared favourably.

  16. West Nile virus adaptation to ixodid tick cells is associated with phenotypic trade-offs in primary hosts.

    Science.gov (United States)

    Ciota, Alexander T; Payne, Anne F; Kramer, Laura D

    2015-08-01

    West Nile virus (WNV; Flaviviridae, Flavivirus) is the most geographically widespread arthropod-borne virus (arbovirus) in the world and is found in multiple ecologically distinct settings. Despite the likelihood of frequent exposure to novel hosts, studies evaluating the capacity and correlates of host range expansions or shifts of WNV and other arboviruses are generally lacking. We utilized experimental evolution of WNV in an Amblyomma americanum tick cell line to model an invertebrate host shift and evaluate the adaptive potential of WNV outside of its primary transmission cycle. Our results demonstrate that highly significant gains in replicative ability in ixodid tick cells are attainable for WNV but are also associated with widespread genetic change and significant phenotypic costs in vitro. Decreased fitness in primary hosts could represent a barrier to frequent exploitation of hard ticks by WNV in nature.

  17. Evidence of expanded host range and mammalian-associated genetic changes in a duck H9N2 influenza virus following adaptation in quail and chickens.

    Directory of Open Access Journals (Sweden)

    Md Jaber Hossain

    Full Text Available H9N2 avian influenza viruses continue to circulate worldwide; in Asia, H9N2 viruses have caused disease outbreaks and established lineages in land-based poultry. Some H9N2 strains are considered potentially pandemic because they have infected humans causing mild respiratory disease. In addition, some of these H9N2 strains replicate efficiently in mice without prior adaptation suggesting that H9N2 strains are expanding their host range. In order to understand the molecular basis of the interspecies transmission of H9N2 viruses, we adapted in the laboratory a wildtype duck H9N2 virus, influenza A/duck/Hong Kong/702/79 (WT702 virus, in quail and chickens through serial lung passages. We carried out comparative analysis of the replication and transmission in quail and chickens of WT702 and the viruses obtained after 23 serial passages in quail (QA23 followed by 10 serial passages in chickens (QA23CkA10. Although the WT702 virus can replicate and transmit in quail, it replicates poorly and does not transmit in chickens. In contrast, the QA23CkA10 virus was very efficient at replicating and transmitting in quail and chickens. Nucleotide sequence analysis of the QA23 and QA23CkA10 viruses compared to the WT702 virus indicated several nucleotide substitutions resulting in amino acid changes within the surface and internal proteins. In addition, a 21-amino acid deletion was found in the stalk of the NA protein of the QA23 virus and was maintained without further modification in the QA23CkA10 adapted virus. More importantly, both the QA23 and the QA23CkA10 viruses, unlike the WT702 virus, were able to readily infect mice, produce a large-plaque phenotype, showed faster replication kinetics in tissue culture, and resulted in the quick selection of the K627 amino acid mammalian-associated signature in PB2. These results are in agreement with the notion that adaptation of H9 viruses to land-based birds can lead to strains with expanded host range.

  18. Hearing in the African lungfish (Protopterus annectens): pre-adaptation to pressure hearing in tetrapods?

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, Jakob; Brandt, Christian; Wilson, Maria;

    2010-01-01

    Lungfishes are the closest living relatives of the tetrapods, and the ear of recent lungfishes resembles the tetrapod ear more than the ear of ray-finned fishes and is therefore of interest for understanding the evolution of hearing in the early tetrapods. The water-to-land transition resulted...... responses of five West African lungfish (Protopterus annectens) using brainstem potentials evoked by calibrated sound and vibration stimuli in air and water. We find that the lungfish ear has good low-frequency vibration sensitivity, like recent amphibians, but poor sensitivity to air-borne sound. The skull...

  19. Ebola Virus Disease

    Science.gov (United States)

    ... Marburg virus outbreaks: Ebola and Marburg virus disease epidemics: preparedness, alert, control, and evaluation When an outbreak ... Offices WHO African Region WHO Region of the Americas WHO South-East Asia Region WHO European Region ...

  20. Shared usage of the chemokine receptor CXCR4 by primary and laboratory-adapted strains of feline immunodeficiency virus.

    Science.gov (United States)

    Richardson, J; Pancino, G; Merat, R; Leste-Lasserre, T; Moraillon, A; Schneider-Mergener, J; Alizon, M; Sonigo, P; Heveker, N

    1999-05-01

    Strains of the feline immunodeficiency virus (FIV) presently under investigation exhibit distinct patterns of in vitro tropism. In particular, the adaptation of FIV for propagation in Crandell feline kidney (CrFK) cells results in the selection of strains capable of forming syncytia with cell lines of diverse species origin. The infection of CrFK cells by CrFK-adapted strains appears to require the chemokine receptor CXCR4 and is inhibited by its natural ligand, stromal cell-derived factor 1alpha (SDF-1alpha). Here we found that inhibitors of CXCR4-mediated infection by human immunodeficiency virus type I (HIV-1), such as the bicyclam AMD3100 and short peptides derived from the amino-terminal region of SDF-1alpha, also blocked infection of CrFK by FIV. Nevertheless, we observed differences in the ranking order of the peptides as inhibitors of FIV and HIV-1 and showed that such differences are related to the species origin of CXCR4 and not that of the viral envelope. These results suggest that, although the envelope glycoproteins of FIV and HIV-1 are substantially divergent, FIV and HIV-1 interact with CXCR4 in a highly similar manner. We have also addressed the role of CXCR4 in the life cycle of primary isolates of FIV. Various CXCR4 ligands inhibited infection of feline peripheral blood mononuclear cells (PBMC) by primary FIV isolates in a concentration-dependent manner. These ligands also blocked the viral transduction of feline PBMC by pseudotyped viral particles when infection was mediated by the envelope glycoprotein of a primary FIV isolate but not by the G protein of vesicular stomatitis virus, indicating that they act at an envelope-mediated step and presumably at viral entry. These findings strongly suggest that primary and CrFK-adapted strains of FIV, despite disparate in vitro tropisms, share usage of CXCR4.

  1. Genome scale evolution of myxoma virus reveals host-pathogen adaptation and rapid geographic spread.

    Science.gov (United States)

    Kerr, Peter J; Rogers, Matthew B; Fitch, Adam; Depasse, Jay V; Cattadori, Isabella M; Twaddle, Alan C; Hudson, Peter J; Tscharke, David C; Read, Andrew F; Holmes, Edward C; Ghedin, Elodie

    2013-12-01

    The evolutionary interplay between myxoma virus (MYXV) and the European rabbit (Oryctolagus cuniculus) following release of the virus in Australia in 1950 as a biological control is a classic example of host-pathogen coevolution. We present a detailed genomic and phylogeographic analysis of 30 strains of MYXV, including the Australian progenitor strain Standard Laboratory Strain (SLS), 24 Australian viruses isolated from 1951 to 1999, and three isolates from the early radiation in Britain from 1954 and 1955. We show that in Australia MYXV has spread rapidly on a spatial scale, with multiple lineages cocirculating within individual localities, and that both highly virulent and attenuated viruses were still present in the field through the 1990s. In addition, the detection of closely related virus lineages at sites 1,000 km apart suggests that MYXV moves freely in geographic space, with mosquitoes, fleas, and rabbit migration all providing means of transport. Strikingly, despite multiple introductions, all modern viruses appear to be ultimately derived from the original introductions of SLS. The rapidity of MYXV evolution was also apparent at the genomic scale, with gene duplications documented in a number of viruses. Duplication of potential virulence genes may be important in increasing the expression of virulence proteins and provides the basis for the evolution of novel functions. Mutations leading to loss of open reading frames were surprisingly frequent and in some cases may explain attenuation, but no common mutations that correlated with virulence or attenuation were identified.

  2. Adaptation of the Rapid Estimate of Adult Litera cy in Medicine Revised (REALM -R to the South African context: Part 1

    Directory of Open Access Journals (Sweden)

    Todd Mavis Maja

    2010-03-01

    Full Text Available

    Literacy levels are increasingly important in health care because professional nurses and other health care professionals often use written health education materials as a major component in patient education. In South Africa, no current instrument is available to assess the literacy levels of patients in the primary health care setting, though several instruments have been developed and validated internationally. The purpose of this paper was to adapt and validate the Rapid Estimate of Adult Literacy in Medicine Revised (REALM-R to the South African context. The REALM-R is a short instrument that is designed to rapidly screen clients in the primary health care setting for low health literacy. A modified Delphi-technique was used to measure the judgement of a group of experts for the purpose of making a decision. Eight experts in the field of Nursing Science were selected purposively to obtain the most reliable consensus. Data was collected by means of a selfreport whereby participants responded to a series of questions posed by the researcher. Descriptive statistics was used for analysing data. The REALM-R was adapted to the South African context to ensure that the literacy level of South African clients is measured with an appropriate instrument.


    Opsomming
    Geletterdheidsvlakke word toenemend belangrik in gesondheidsorg aangesien geregistreerde verpleegkundiges en ander gesondheidswerkers dikwels geskrewe gesondheidopvoedkundige materiaal gebruik. Op die oomblik in Suid-Afrika is daar geen geletterdheidsvlaksinstrument beskikbaar om pasiënte in primêre gesondheidsorg se geletterdheid te toets nie. Daar bestaan wel gevalideerde internasionale instrumente. Die doel van die studie was om die REALM-R, ‘n internasionaal gevalideerde mediese geletterdheidsinstrument, aan te pas en te valideer om in die Suid-Afrikaanse konteks gebruik te kan word. Die REALM-R is ‘n kort geletterdheidsinstrument wat ontwikkel

  3. Influence of retinoblastoma-related gene silencing on the initiation of DNA replication by African cassava mosaic virus Rep in cells of mature leaves in Nicotiana benthamiana plants

    Directory of Open Access Journals (Sweden)

    Bruce Gareth

    2011-12-01

    Full Text Available Abstract Background Geminiviruses mainly infect terminally differentiated tissues and cells in plants. They need to reprogramme host cellular machinery for DNA replication. This process is thought to be mediated by inactivation of cell-cycle repressor proteins and by induction of host DNA synthesis protein expression through actions of the geminviral replication initiator protein (Rep. Findings Exploiting a Nicotiana benthamiana pOri2 line, which is transformed with a transgene consisting of a direct repeat of the African cassava mosaic virus (ACMV-replication origin (Ori flanking a non-viral DNA region, and virus-induced RNA silencing (VIGS, the impact of host gene expression on replication of the ACMV-derived replicon was investigated. The ACMV Rep trans-replicated the viral episomal replicon in leaves of young but not older pOri2 plants. Upon VIGS-mediated down-regulation of N. benthamiana NbRBR1, the retinoblastoma-related protein gene coding for a negative cell-cycle suppressor, recovered the ability of ACMV Rep for trans DNA replication, whereas the silencing of NbPCNA coding for the sliding clamp of DNA polymerase had no effect. Conclusions These results suggest that the cellular machinery for DNA replication in differentiated tissues of older leaves cannot be reprogrammed by Rep alone but may need other uncharacterised viral and plant factors.

  4. Molecular genome tracking of East, Central and South African genotype of Chikungunya virus in South-east Asia between 2006 and 2009

    Institute of Scientific and Technical Information of China (English)

    Kamol Suwannakarn; Apiradee Theamboonlers; Yong Poovorawan

    2011-01-01

    Objective:To understand the epidemiology of the East, Central and South African(ECSA) genotype of Chikungunya virus(CHIKV)in terms of emerging and re-emerging infections, this study has been aimed at investigating the evolutionary parameters, genomic signatures and molecular tracking of theCHIKV ECSA genotype in South-east Asia and coastal areas of the Indian Ocean between 2006 and 2009 by using phylogenetic analysis and the Bayesian Markov Chain Monte Carlo (BMCMC) evolutionary estimation.Methods: Nearly complete genome sequences of53 CHIKV isolates from all genotypes were subjected to phylogenetic analysis and evolutionary parameter estimation. The amino acids of67of ECSA genotype during2006 to2009 were compared for finding molecular signature tracking. The ECSA genotype signatures were visualized to find the possible transmission root was projected onto a geographic map.Results:Phylogenetic analysis showed theECSA genotype was divided into2 groups. The first group comprises viruses from India and Southeast Asian countries. The second group consists of strains typically circulating in Sri Lanka in2008. The evolutionary parameters of these groups depicted the time of the most recent common ancestor at approximately 7.5years ago. The genomic signatures revealed the positions of amino acid variation in each group.Conclusions:The molecular evolution projected onto a geographical map showed the routes ofCHIKVtransmission from 2006 to2009. Molecular tracking will assist in understanding transmission routes, epidemiology and molecular evolution ofCHIKV.

  5. Exploring sexual practices of South African soldiers to determine their vulnerability to the human immune-deficiency virus

    Directory of Open Access Journals (Sweden)

    Angela De Jong

    2006-03-01

    Full Text Available Although HIV occurs in all social groups in South African society, certain populations are more vulnerable to HIV through risky behaviour patterns. Of relevance to the present study are the high risk situations that deployed soldiers are exposed to. Three issues indicated the necessity for a study of this kind to be conducted; (a the statistics pointing to a higher incidence of HIV infections among military personnel than among the general population, (b military personnel’s unique vulnerability profile, and (c the South African National Defence Force’s (SANDF increasing participation in international peacekeeping missions. The knowledge, attitudes and practices concerning HIV/AIDS of deployed soldiers were analysed. Results indicated that soldiers were taking sexual risks, although they had high levels of knowledge and had healthy attitudes concerning HIV/AIDS.

  6. Counteracting quasispecies adaptability: extinction of a ribavirin-resistant virus mutant by an alternative mutagenic treatment.

    Directory of Open Access Journals (Sweden)

    Celia Perales

    Full Text Available BACKGROUND: Lethal mutagenesis, or virus extinction promoted by mutagen-induced elevation of mutation rates of viruses, may meet with the problem of selection of mutagen-resistant variants, as extensively documented for standard, non-mutagenic antiviral inhibitors. Previously, we characterized a mutant of foot-and-mouth disease virus that included in its RNA-dependent RNA polymerase replacement M296I that decreased the sensitivity of the virus to the mutagenic nucleoside analogue ribavirin. METHODOLOGY AND PRINCIPAL FINDINGS: Replacement M296I in the viral polymerase impedes the extinction of the mutant foot-and-mouth disease virus by elevated concentrations of ribavirin. In contrast, wild type virus was extinguished by the same ribavirin treatment and, interestingly, no mutants resistant to ribavirin were selected from the wild type populations. Decreases of infectivity and viral load of the ribavirin-resistant M296I mutant were attained with a combination of the mutagen 5-fluorouracil and the non-mutagenic inhibitor guanidine hydrocloride. However, extinction was achieved with a sequential treatment, first with ribavirin, and then with a minimal dose of 5-fluorouracil in combination with guanidine hydrochloride. Both, wild type and ribavirin-resistant mutant M296I exhibited equal sensitivity to this combination, indicating that replacement M296I in the polymerase did not confer a significant cross-resistance to 5-fluorouracil. We discuss these results in relation to antiviral designs based on lethal mutagenesis. CONCLUSIONS: (i When dominant in the population, a mutation that confers partial resistance to a mutagenic agent can jeopardize virus extinction by elevated doses of the same mutagen. (ii A wild type virus, subjected to identical high mutagenic treatment, need not select a mutagen-resistant variant, and the population can be extinguished. (iii Extinction of the mutagen-resistant variant can be achieved by a sequential treatment of a

  7. Investigation into the Epidemiology of African Swine Fever Virus at the Wildlife - Domestic Interface of the Gorongosa National Park, Central Mozambique.

    Science.gov (United States)

    Quembo, C J; Jori, F; Heath, L; Pérez-Sánchez, R; Vosloo, W

    2016-08-01

    An epidemiological study of African swine fever (ASF) was conducted between March 2006 and September 2007 in a rural area adjacent to the Gorongosa National park (GNP) located in the Central Mozambique. Domestic pigs and warthogs were sampled to determine the prevalence of antibodies against ASF virus and the salivary antigens of Ornithodoros spp. ticks, while ticks collected from pig pens were tested for the presence of ASFV. In addition, 310 framers were interviewed to gain a better understanding of the pig value chain and potential practices that could impact on the spread of the virus. The sero-prevalence to ASFV was 12.6% on farms and 9.1% in pigs, while it reached 75% in warthogs. Approximately 33% of pigs and 78% of warthogs showed antibodies against salivary antigens of ticks. The differences in sero-prevalence between farms close to the GNP, where there is greater chance for the sylvatic cycle to cause outbreaks, and farms located in the rest of the district, where pig to pig transmission is more likely to occur, were marginally significant. Ornithodoros spp. ticks were found in only 2 of 20 pig pens outside the GNP, and both pens had ticks testing positive for ASFV DNA. Interviews carried out among farmers indicated that biosecurity measures were mostly absent. Herd sizes were small with pigs kept in a free-ranging husbandry system (65%). Only 1.6% of farmers slaughtered on their premises, but 51% acknowledged allowing visitors into their farms to purchase pigs. ASF outbreaks seemed to have a severe economic impact with nearly 36% of farmers ceasing pig farming for at least 1 year after a suspected ASF outbreak. This study provides the first evidence of the existence of a sylvatic cycle in Mozambique and confirms the presence of a permanent source of virus for the domestic pig value chain.

  8. The Chlorella variabilis NC64A Genome Reveals Adaptation to Photosymbiosis, Coevolution with Viruses, and Cryptic Sex

    Energy Technology Data Exchange (ETDEWEB)

    Blanc, Guillaume; Duncan, Garry A.; Agarakova, Irina; Borodovsky, Mark; Gurnon, James; Kuo, Alan; Lindquist, Erika; Lucas, Susan; Pangailinan, Jasmyn; Polle, Juergen; Salamov, Asaf; Terry, Astrid; Yamada, Takashi; Dunigan, David D.; Grigoriev, Igor V.; Claverie, Jean-Michel; Etten, James L. Van

    2010-05-06

    Chlorella variabilis NC64A, a unicellular photosynthetic green alga (Trebouxiophyceae), is an intracellular photobiont of Paramecium bursaria and a model system for studying virus/algal interactions. We sequenced its 46-Mb nuclear genome, revealing an expansion of protein families that could have participated in adaptation to symbiosis. NC64A exhibits variations in GC content across its genome that correlate with global expression level, average intron size, and codon usage bias. Although Chlorella species have been assumed to be asexual and nonmotile, the NC64A genome encodes all the known meiosis-specific proteins and a subset of proteins found in flagella. We hypothesize that Chlorella might have retained a flagella-derived structure that could be involved in sexual reproduction. Furthermore, a survey of phytohormone pathways in chlorophyte algae identified algal orthologs of Arabidopsis thaliana genes involved in hormone biosynthesis and signaling, suggesting that these functions were established prior to the evolution of land plants. We show that the ability of Chlorella to produce chitinous cell walls likely resulted from the capture of metabolic genes by horizontal gene transfer from algal viruses, prokaryotes, or fungi. Analysis of the NC64A genome substantially advances our understanding of the green lineage evolution, including the genomic interplay with viruses and symbiosis between eukaryotes.

  9. Melon chlorotic leaf curl virus: characterization and differential reassortment with closest relatives reveal adaptive virulence in the squash leaf curl virus clade and host shifting by the host-restricted bean calico mosaic virus.

    Science.gov (United States)

    Idris, A M; Mills-Lujan, K; Martin, K; Brown, J K

    2008-02-01

    The genome components of the Melon chlorotic leaf curl virus (MCLCuV) were cloned from symptomatic cantaloupe leaves collected in Guatemala during 2002. The MCLCuV DNA-A and DNA-B components shared their closest nucleotide identities among begomoviruses, at approximately 90 and 81%, respectively, with a papaya isolate of MCLCuV from Costa Rica. The closest relatives at the species level were other members of the Squash leaf curl virus (SLCV) clade, which is endemic in the southwestern United States and Mexico. Biolistic inoculation of cantaloupe seedlings with the MCLCuV DNA-A and -B components resulted in the development of characteristic disease symptoms, providing definitive evidence of causality. MCLCuV experimentally infected species within the Cucurbitaceae, Fabaceae, and Solanaceae. The potential for interspecific reassortment was examined for MCLCuV and its closest relatives, including the bean-restricted Bean calico mosaic virus (BCaMV), and three other cucurbit-infecting species, Cucurbit leaf crumple virus (CuLCrV), SLCV, and SMLCV. The cucurbit viruses have distinct but overlapping host ranges. All possible reassortants were established using heterologous combinations of the DNA-A or DNA-B components. Surprisingly, only certain reassortants arising from MCLCuV and BCaMV, or MCLCuV and CuLCrV, were viable in bean, even though it is a host of all of the "wild-type" (parent) viruses. The bean-restricted BCaMV was differentially assisted in systemically infecting the cucurbit test species by the components of the four cucurbit-adapted begomoviruses. In certain heterologous combinations, the BCaMV DNA-A or -B component was able to infect one or more cucurbit species. Generally, the reassortants were less virulent in the test hosts than the respective wild-type (parent) viruses, strongly implicating adaptive modulation of virulence. This is the first illustration of reassortment resulting in the host range expansion of a host-restricted begomovirus.

  10. WASCAL - West African Science Service Center on Climate Change and Adapted Land Use Regional Climate Simulations and Land-Atmosphere Simulations for West Africa at DKRZ and elsewhere

    Science.gov (United States)

    Hamann, Ilse; Arnault, Joel; Bliefernicht, Jan; Klein, Cornelia; Heinzeller, Dominikus; Kunstmann, Harald

    2014-05-01

    Changing climate and hydro-meteorological boundary conditions are among the most severe challenges to Africa in the 21st century. In particular West Africa faces an urgent need to develop effective adaptation and mitigation strategies to cope with negative impacts on humans and environment due to climate change, increased hydro-meteorological variability and land use changes. To help meet these challenges, the German Federal Ministry of Education and Research (BMBF) started an initiative with institutions in Germany and West African countries to establish together a West African Science Service Center on Climate Change and Adapted Land Use (WASCAL). This activity is accompanied by an establishment of trans-boundary observation networks, an interdisciplinary core research program and graduate research programs on climate change and related issues for strengthening the analytical capabilities of the Science Service Center. A key research activity of the WASCAL Competence Center is the provision of regional climate simulations in a fine spatio-temporal resolution for the core research sites of WASCAL for the present and the near future. The climate information is needed for subsequent local climate impact studies in agriculture, water resources and further socio-economic sectors. The simulation experiments are performed using regional climate models such as COSMO-CLM, RegCM and WRF and statistical techniques for a further refinement of the projections. The core research sites of WASCAL are located in the Sudanian Savannah belt in Northern Ghana, Southern Burkina Faso and Northern Benin. The climate in this region is semi-arid with six rainy months. Due to the strong population growth in West Africa, many areas of the Sudanian Savannah have been already converted to farmland since the majority of the people are living directly or indirectly from the income produced in agriculture. The simulation experiments of the Competence Center and the Core Research Program are

  11. Climate Change and Potato Production in Contrasting South African Agro-Ecosystems 2. Assessing Risks and Opportunities of Adaptation Strategies

    NARCIS (Netherlands)

    Franke, A.C.; Haverkort, A.J.; Steyn, J.M.

    2013-01-01

    This study aims to assess the risks and opportunities posed by climate change to potato growers in South Africa and to evaluate adaptation measures in the form of changes in planting time growers could adopt to optimise land and water use efficiencies in potato, using a climate model of past, presen

  12. PB2-588 V promotes the mammalian adaptation of H10N8, H7N9 and H9N2 avian influenza viruses.

    Science.gov (United States)

    Xiao, Chencheng; Ma, Wenjun; Sun, Na; Huang, Lihong; Li, Yaling; Zeng, Zhaoyong; Wen, Yijun; Zhang, Zaoyue; Li, Huanan; Li, Qian; Yu, Yuandi; Zheng, Yi; Liu, Shukai; Hu, Pingsheng; Zhang, Xu; Ning, Zhangyong; Qi, Wenbao; Liao, Ming

    2016-01-19

    Human infections with avian influenza H7N9 or H10N8 viruses have been reported in China, raising concerns that they might cause human epidemics and pandemics. However, how these viruses adapt to mammalian hosts is unclear. Here we show that besides the commonly recognized viral polymerase subunit PB2 residue 627 K, other residues including 87E, 292 V, 340 K, 588 V, 648 V, and 676 M in PB2 also play critical roles in mammalian adaptation of the H10N8 virus. The avian-origin H10N8, H7N9, and H9N2 viruses harboring PB2-588 V exhibited higher polymerase activity, more efficient replication in mammalian and avian cells, and higher virulence in mice when compared to viruses with PB2-588 A. Analyses of available PB2 sequences showed that the proportion of avian H9N2 or human H7N9 influenza isolates bearing PB2-588 V has increased significantly since 2013. Taken together, our results suggest that the substitution PB2-A588V may be a new strategy for an avian influenza virus to adapt mammalian hosts.

  13. Detection of Hepatitis B Virus (HBV) Genotype E Carried—Even in the Presence of High Titers of Anti-HBs Antibodies—by an Argentinean Patient of African Descent Who Had Received Vaccination against HBV

    Science.gov (United States)

    Mathet, Verónica L.; Cuestas, María L.; Ruiz, Vanesa; Minassian, María L.; Rivero, Cintia; Trinks, Julieta; Daleoso, Graciela; León, Liliana M.; Sala, Andrea; Libellara, Beatriz; Corach, Daniel; Oubiña, José R.

    2006-01-01

    Genotype E hepatitis B virus (HBV) was detected in two Argentine sisters exhibiting an African mitochondrial lineage. One of them (who had been vaccinated against HBV) exhibited anti-HBs cocirculating antibodies without HBsAg escape mutants, while her unvaccinated sister showed a D144A HBsAg escape mutant without anti-HBs antibodies. Both sisters carried an unusual L209V substitution within HBsAg. PMID:16954295

  14. Organizational adaptation to Complexity: A study of the South African Insurance Market as a Complex Adaptive System through Statistical Risk Analysis

    CERN Document Server

    Paul, Satyakama; Marwala, Tshilidzi

    2011-01-01

    South Africa assumes a significant position in the insurance landscape of Africa. The present research based upon qualitative and quantitative analysis, shows that it shows the characteristics of a Complex Adaptive System. In addition, a statistical analysis of risk measures through Value at risk and Conditional tail expectation is carried out to show how an individual insurance company copes under external complexities. The authors believe that an explanation of the coping strategies, and the subsequent managerial implications would enrich our understanding of complexity in business.

  15. Variability of the preC/C region of hepatitis B virus genotype A from a South African cohort predominantly infected with HIV.

    Science.gov (United States)

    Mayaphi, Simnikiwe H; Martin, Desmond J; Mphahlele, M Jeffrey; Blackard, Jason T; Bowyer, Sheila M

    2013-11-01

    Hepatitis B virus (HBV) is a serious global health problem, and HBV genotype is an important determinant of disease progression and treatment outcome. The aim of this study was to assess variations of the precore/core (preC/C) region in HBV genotype A. Sequencing of the preC/C and surface (S) genes of HBV was performed on plasma samples from 20 HBV/HIV co-infected and 5 HBV mono-infected individuals. All preC/C study sequences clustered with subgenotype A1, except for two which clustered with subgenotype D4 reference strains. The nucleotide and amino acid variability was far higher in the preC/C region than in the S region. Mutations associated with reduction or failure of HBV e-antigen (HBeAg) production were observed, with a preC start codon mutation being common (24%). Other mutations (e.g., P5H/L and I97L) associated with severe liver disease were also noticed, some of which were located in the major histocompatibility restricted sites. PreC/C intergenotype nucleotide divergence was >7%, while subgenotypes differed by 2.5-7%. Several study sequences were highly divergent from other African subgenotype A1 strains. This study showed that HBeAg-negative chronic hepatitis B is underestimated in subgenotype A1, and also highlighted the variant South African A1 strains. The major advantage of preC/C sequencing is that it informs patient management as HBeAg-negative chronic hepatitis B responds poorly to conventional interferon-α therapy, and some guidelines treat HBeAg-negative chronic hepatitis B differently from HBeAg-positive chronic hepatitis B. These data suggest that subgenotype A1 may be more involved in severe HBV-related diseases.

  16. Detection of African Swine Fever Virus Antibodies in Serum and Oral Fluid Specimens Using a Recombinant Protein 30 (p30) Dual Matrix Indirect ELISA

    Science.gov (United States)

    Giménez-Lirola, Luis G.; Mur, Lina; Rivera, Belen; Mogler, Mark; Sun, Yaxuan; Lizano, Sergio; Goodell, Christa; Harris, D. L. Hank; Rowland, Raymond R. R.; Gallardo, Carmina; Sánchez-Vizcaíno, José Manuel; Zimmerman, Jeff

    2016-01-01

    In the absence of effective vaccine(s), control of African swine fever caused by African swine fever virus (ASFV) must be based on early, efficient, cost-effective detection and strict control and elimination strategies. For this purpose, we developed an indirect ELISA capable of detecting ASFV antibodies in either serum or oral fluid specimens. The recombinant protein used in the ELISA was selected by comparing the early serum antibody response of ASFV-infected pigs (NHV-p68 isolate) to three major recombinant polypeptides (p30, p54, p72) using a multiplex fluorescent microbead-based immunoassay (FMIA). Non-hazardous (non-infectious) antibody-positive serum for use as plate positive controls and for the calculation of sample-to-positive (S:P) ratios was produced by inoculating pigs with a replicon particle (RP) vaccine expressing the ASFV p30 gene. The optimized ELISA detected anti-p30 antibodies in serum and/or oral fluid samples from pigs inoculated with ASFV under experimental conditions beginning 8 to 12 days post inoculation. Tests on serum (n = 200) and oral fluid (n = 200) field samples from an ASFV-free population demonstrated that the assay was highly diagnostically specific. The convenience and diagnostic utility of oral fluid sampling combined with the flexibility to test either serum or oral fluid on the same platform suggests that this assay will be highly useful under the conditions for which OIE recommends ASFV antibody surveillance, i.e., in ASFV-endemic areas and for the detection of infections with ASFV isolates of low virulence. PMID:27611939

  17. One PCR Method Used for Detection of African Swine Fever Virus%一种用于非洲猪瘟病毒检测的PCR方法

    Institute of Scientific and Technical Information of China (English)

    杨吉飞; 苟惠天; 杜鹏飞; 罗建勋; 殷宏; 关贵全; 刘志杰; 汪月凤; 李有全; 马米玲; 刘爱红; 任巧云; 陈泽

    2011-01-01

    基于非洲猪瘟病毒( ASFV) VP72基因设计引物,建立一种检测非洲猪瘟病毒的PCR方法.应用本研究所建立的方法与OIE参考的方法进行比较,并对参考实验室提供的非洲猪瘟病毒17个分离株的基因组以及本实验室收集的野外样品进行检测.结果显示:本研究设计的引物具有良好的特异性,与猪的其他病原没有交叉反应;其敏感性与OIE参考的方法相当;所建立的PCR方法能够成功扩增非洲猪瘟病毒17个分离株的基因组,野外样品检测均为阴性.根据上述研究结果,本研究所建立的方法具有很好的应用性,能够用于非洲猪瘟疫病的诊断以及防控.%A polymerase chain reaction (PCR) was developed for detection of African swine fever virus (ASFV) based on the VP72 gene. This method was compared with the PCR method which was recommended for diagnosis of African swine fever by OIE. Seventeen genomic DNAs of ASFV isolates from ASF reference laboratory and some field samples collected from China were detected by PCR, respectively. The results revealed that it had a good specificity, no cross-reaction was observed with other pig pathogens. The sensitivity was equivalent to the PCR which was recommended by OIE. Seventeen genomic DNAs of ASFV isolates could be detected successfully, but all of the field samples were negative. This method has a good applicability and could be used in diagnosis, prevention and control of African swine fever.

  18. Inter- and intramolecular recombinations in the cucumber mosaic virus genome related to adaptation to alstroemeria.

    Science.gov (United States)

    Chen, Yuh-Kun; Goldbach, Rob; Prins, Marcel

    2002-04-01

    In four distinct alstroemeria-infecting cucumber mosaic virus (CMV) isolates, additional sequences of various lengths were present in the 3' nontranslated regions of their RNAs 2 and 3, apparently the result of intra- and intermolecular recombination events. Competition experiments revealed that these recombined RNA 2 and 3 segments increased the biological fitness of CMV in alstroemeria.

  19. Evolution of highly pathogenic avian influenza H5N1 viruses in Egypt indicating progressive adaptation

    Science.gov (United States)

    Highly pathogenic avian influenza (HPAI) virus of the H5N1 subtype was first diagnosed in poultry in Egypt in 2006, and since then the disease became enzootic in poultry throughout the country affecting the poultry industry and village poultry as well as infecting humans. Vaccination has been used ...

  20. Inter- and Intramolecular recombinations in the Cucumber Mosaic Virus genome related to adaptation to Alstroemeria

    NARCIS (Netherlands)

    Chen, Y.K.; Goldbach, R.W.; Prins, M.W.

    2002-01-01

    In four distinct alstroemeria-infecting cucumber mosaic virus (CMV) isolates, additional sequences of various lengths were present in the 3' nontranslated regions of their RNAs 2 and 3, apparently the result of intra- and intermolecular recombination events. Competition experiments revealed that the

  1. Genome-wide analysis for identification of adaptive diversification between hepatitis C virus subtypes 1a and 1b.

    Science.gov (United States)

    Li, Yan; Wang, Ruirui; Du, Xiaogang; Zhang, Mingwang; Xie, Meng

    2016-07-01

    Hepatitis C virus (HCV) is a major cause of liver disease and has been estimated to infect approximately 2%-3% of the world's population. HCV genotype 1 is the subject of intense research and clinical investigations because of its worldwide prevalence and poor access to treatment for patients in developing countries and marginalized populations. The predominant subtypes 1a and 1b of HCV genotype 1 present considerable differences in epidemiological features. However, the genetic signature underlying such phenotypic functional divergence is still an open question. Here, we performed a genome-wide evolutionary study on HCV subtypes 1a and 1b. The results show that adaptive selection has driven the diversification between these subtypes. Furthermore, the major adaptive divergence-related changes have occurred on proteins E1, NS4B, NS5A, and NS5B. Structurally, a number of adaptively selected sites cluster in functional regions potentially relevant to (i) membrane attachment and (ii) the interactions with viral and host cell factors and the genome template. These results might provide helpful hints about the molecular determinants of epidemiological divergence between HCV 1a and 1b.

  2. Genetic Diversity of the Hepatitis B Virus Strains in Cuba: Absence of West-African Genotypes despite the Transatlantic Slave Trade.

    Directory of Open Access Journals (Sweden)

    Licel A Rodríguez Lay

    Full Text Available Cuba is an HBsAg low-prevalence country with a high coverage of anti-hepatitis B vaccine. Its population is essentially the result of the population mix of Spanish descendants and former African slaves. Information about genetic characteristics of hepatitis B virus (HBV strains circulating in the country is scarce. The HBV genotypes/subgenotypes, serotypes, mixed infections, and S gene mutations of 172 Cuban HBsAg and HBV-DNA positive patients were determined by direct sequencing and phylogenetic analysis. Phylogenetic analysis of HBV S gene sequences showed a predominance of genotype A (92.4%, subgenotype A2 (84.9% and A1 (7.6%. Genotype D (7.0% and subgenotype C1 (0.6% were also detected but typical (subgenotypes of contemporary West-Africa (E, A3 were conspicuously absent. All genotype A, D, and C strains exhibited sequence characteristics of the adw2, ayw2, and adrq serotypes, respectively. Thirty-three (19.1% patients showed single, double, or multiple point mutations inside the Major Hydrophilic domain associated with vaccine escape; eighteen (10.5% patients had mutations in the T-cell epitope (amino acids 28-51, and there were another 111 point mutations downstream of the S gene. One patient had an HBV A1/A2 mixed infection. This first genetic study of Cuban HBV viruses revealed only strains that were interspersed with strains from particularly Europe, America, and Asia. The absence of genotype E supports previous hypotheses about an only recent introduction of this genotype into the general population in Africa. The presence of well-known vaccine escape (3.5% and viral resistance mutants (2.9% warrants strain surveillance to guide vaccination and treatment strategies.

  3. Genetic Diversity of the Hepatitis B Virus Strains in Cuba: Absence of West-African Genotypes despite the Transatlantic Slave Trade.

    Science.gov (United States)

    Rodríguez Lay, Licel A; Corredor, Marité B; Villalba, Maria C; Frómeta, Susel S; Wong, Meilin S; Valdes, Lidunka; Samada, Marcia; Sausy, Aurélie; Hübschen, Judith M; Muller, Claude P

    2015-01-01

    Cuba is an HBsAg low-prevalence country with a high coverage of anti-hepatitis B vaccine. Its population is essentially the result of the population mix of Spanish descendants and former African slaves. Information about genetic characteristics of hepatitis B virus (HBV) strains circulating in the country is scarce. The HBV genotypes/subgenotypes, serotypes, mixed infections, and S gene mutations of 172 Cuban HBsAg and HBV-DNA positive patients were determined by direct sequencing and phylogenetic analysis. Phylogenetic analysis of HBV S gene sequences showed a predominance of genotype A (92.4%), subgenotype A2 (84.9%) and A1 (7.6%). Genotype D (7.0%) and subgenotype C1 (0.6%) were also detected but typical (sub)genotypes of contemporary West-Africa (E, A3) were conspicuously absent. All genotype A, D, and C strains exhibited sequence characteristics of the adw2, ayw2, and adrq serotypes, respectively. Thirty-three (19.1%) patients showed single, double, or multiple point mutations inside the Major Hydrophilic domain associated with vaccine escape; eighteen (10.5%) patients had mutations in the T-cell epitope (amino acids 28-51), and there were another 111 point mutations downstream of the S gene. One patient had an HBV A1/A2 mixed infection. This first genetic study of Cuban HBV viruses revealed only strains that were interspersed with strains from particularly Europe, America, and Asia. The absence of genotype E supports previous hypotheses about an only recent introduction of this genotype into the general population in Africa. The presence of well-known vaccine escape (3.5%) and viral resistance mutants (2.9%) warrants strain surveillance to guide vaccination and treatment strategies.

  4. Intranasal Immunization with Influenza Virus-Like Particles Containing Membrane-Anchored Cholera Toxin B or Ricin Toxin B Enhances Adaptive Immune Responses and Protection against an Antigenically Distinct Virus.

    Science.gov (United States)

    Ji, Xianliang; Ren, Zhiguang; Xu, Na; Meng, Lingnan; Yu, Zhijun; Feng, Na; Sang, Xiaoyu; Li, Shengnan; Li, Yuanguo; Wang, Tiecheng; Zhao, Yongkun; Wang, Hualei; Zheng, Xuexing; Jin, Hongli; Li, Nan; Yang, Songtao; Cao, Jinshan; Liu, Wensen; Gao, Yuwei; Xia, Xianzhu

    2016-04-21

    Vaccination is the most effective means to prevent influenza virus infection, although current approaches are associated with suboptimal efficacy. Here, we generated virus-like particles (VLPs) composed of the hemagglutinin (HA), neuraminidase (NA) and matrix protein (M1) of A/Changchun/01/2009 (H1N1) with or without either membrane-anchored cholera toxin B (CTB) or ricin toxin B (RTB) as molecular adjuvants. The intranasal immunization of mice with VLPs containing membrane-anchored CTB or RTB elicited stronger humoral and cellular immune responses when compared to mice immunized with VLPs alone. Administration of VLPs containing CTB or RTB significantly enhanced virus-specific systemic and mucosal antibody responses, hemagglutination inhibiting antibody titers, virus neutralizing antibody titers, and the frequency of virus-specific IFN-γ and IL-4 secreting splenocytes. VLPs with and without CTB or RTB conferred complete protection against lethal challenge with a mouse-adapted homologous virus. When challenged with an antigenically distinct H1N1 virus, all mice immunized with VLPs containing CTB or RTB survived whereas mice immunized with VLPs alone showed only partial protection (80% survival). Our results suggest that membrane-anchored CTB and RTB possess strong adjuvant properties when incorporated into an intranasally-delivered influenza VLP vaccine. Chimeric influenza VLPs containing CTB or RTB may represent promising vaccine candidates for improved immunological protection against homologous and antigenically distinct influenza viruses.

  5. Relation between phylogeny of African green monkey CD4 genes and their respective simian immunodeficiency virus genes

    DEFF Research Database (Denmark)

    Fomsgaard, Anders; Müller-Trutwin, Michaela C.; Diop, Ousmane

    1997-01-01

    An apparent species-specific relatedness of SIVagm suggests a coevolution with their natural hosts. However, the exact species or subspecies classification of African green monkeys, AGM, is uncertain because current classification schemes rely on phenotype markers, while more definitive genetic...... data are lacking. In this study, the CD4 protein involved in tissue type recognition was gentically cloned and sequence from PBMC RNA from all AGM species, including Barbados green monkeys (BGM). Phylogenetic trees were constructed that also included genomic CD4 nucleotide sequences from patas, sooty...... mangabeys, rhesus and pig-tail macaques, chimpanzees, and humans. Chimpanzees and humans consistently clustered together. Monkeys within the Cercopithecus genus formed a separate cluster which included pata monkeys, supporting its grouping as a member of Cercopithecus. Surprisingly, sooty mangabeys were...

  6. Adapting Evidence-Based Strategies to Increase Physical Activity Among African Americans, Hispanics, Hmong, and Native Hawaiians: A Social Marketing Approach

    Directory of Open Access Journals (Sweden)

    Mary Ann S. Van Duyn, PhD, MPH, RD

    2007-10-01

    Full Text Available IntroductionUsing a social marketing approach, we studied how best to adapt proven, evidence-based strategies to increase physical activity for use with underserved racial or ethnic groups.MethodsWe conducted focus groups with low-income Hispanic women in Texas, Hmong parents and their children in California, low-income African American women and men in the Mississippi Delta, and Native Hawaiian college students in Hawaii. We also interviewed key leaders of these communities. Topics of discussion were participants’ perceptions about 1 the benefits of engaging in physical activity, 2 the proposed evidence-based strategies for increasing each community’s level of physical activity, and 3 the benefits and barriers to following the proposed interventions for increasing physical activity. A total of 292 individuals participated in the study.ResultsAll groups considered that being physically active was part of their culture, and participants found culturally relevant suggestions for physical activities appealing. Overwhelmingly, strategies that aimed to create or improve social support and increase access to physical activity venues received the most positive feedback from all groups. Barriers to physical activity were not culturally specific; they are common to all underserved people (lack of time, transportation, access, neighborhood safety, or economic resources.ConclusionResults indicate that evidence-based strategies to increase physical activity need to be adapted for cultural relevance for each racial or ethnic group. Our research shows that members of four underserved populations are likely to respond to strategies that increase social support for physical activity and improve access to venues where they can be physically active. Further research is needed to test how to implement such strategies in ways that are embraced by community members.

  7. 非洲猪瘟病毒PCR检测试剂盒的研制%Development of a PCR kit for the detection of African swine fever virus

    Institute of Scientific and Technical Information of China (English)

    吴忆春

    2012-01-01

    选取非洲猪瘟病毒(ASFV)结构蛋白基因VP73中保守性强的区域,人工合成该基因片段;再根据GenBank中公布的ASFV的VP73基因序列,设计特异性引物,利用PCR扩增该VP73基因片段,克隆入pET-32a(+)载体,以构建的重组质粒为模板建立了检测ASFV的PCR检测方法。优化扩增条件,并组装成PCR试剂盒。结果显示,PCR扩增出429bp的ASFV VP73基因片段;该试剂盒与猪伪狂犬病病毒、猪瘟病毒(疫苗株)、猪圆环病毒2型、猪繁殖与呼吸综合征病毒、猪乙型脑炎病毒、猪细小病毒、健康猪和蜱的基因组无交叉反应。试剂盒敏感性可达0.1fg。试剂盒批内和批间检测结果无明显差异,稳定性良好。置于4℃和-20℃条件下保存12个月,试剂盒稳定性无明显改变。结果表明,研制的ASFV PCR试剂盒为ASFV的快速检测及流行病学调查提供了技术手段。%The nucleotide sequences of VP73 gene of different African swine fever virus(ASFV) strains available in the GenBank were aligned with DNAStar software,and the highly conserved region was synthesized artificially and amplified with a pair of specific primers. A polymerase chain reaction(PCR) kit was then developed for the detection of ASFV with the amplification conditions optimized. Specificity test showed that there was no cross-reaction with genome of healthy pig or tick,and with different kinds of viruses isolated from swine,including pseudorabies virus, classical swine fever virus(vaccine strain), porcine parvovirus,porcine reproductive and respiratory syndrome virus, Japanese encephalitis virus and porcine circovirus type 2. Sensitivity test proved that the sensitivity of the PCR kit was up to 0.1 fg,and the intra- and inter-repeatability test showed no significant difference,and no significant change was found after being conserved at 4 ℃ or -20 ℃ for 12 months. In conclusion,the developed PCR kit provided technical tools for rapid detection and

  8. Effect of chemicals, heat, and histopathologic processing on high-infectivity hamster-adapted scrapie virus.

    Science.gov (United States)

    Brown, P; Rohwer, R G; Green, E M; Gajdusek, D C

    1982-05-01

    High-titered (greater than 10(10) LD50 [50% lethal dose[/g) preparations of scrapie virus-infected hamster brain were subjected to inactivation by various chemicals, autoclaving, and histopathologic processing. Sodium hypochlorite, which reduced infectivity by approximately 4 log LD50/g of brain (99.99%), was somewhat superior to sodium metaperiodate and clearly superior to chlorine dioxide, Lysol (National Laboratories, Montvale, N.J.), iodine, potassium permanganate, and hydrogen peroxide. Most inactivation occurred within 15-30 min of exposure to a chemical, and little if any additional inactivation occurred after 1 hr. Brains processed for histopathologic examination (formalin fixation followed by dehydration in methanol, clearing in chloroform, and embedding in paraffin) retained greater than or equal to 6.8 log LD50/g of the infectivity present in unprocessed control tissues (9.6 log LD50/g). One hour in an autoclave at 121 C reduced the titer of scrapie virus by approximately 7.5 log LD50/g of brain but left 2.5 log LD50/g of residual infectivity. A combination of exposure to chemicals and autoclaving may be necessary to sterilize high-titered scrapie virus-infected tissue.

  9. Molecular characterization of HIV-1 subtype C gp-120 regions potentially involved in virus adaptive mechanisms.

    Directory of Open Access Journals (Sweden)

    Alessandra Cenci

    Full Text Available The role of variable regions of HIV-1 gp120 in immune escape of HIV has been investigated. However, there is scant information on how conserved gp120 regions contribute to virus escaping. Here we have studied how molecular sequence characteristics of conserved C3, C4 and V3 regions of clade C HIV-1 gp120 that are involved in HIV entry and are target of the immune response, are modulated during the disease course. We found an increase of "shifting" putative N-glycosylation sites (PNGSs in the α2 helix (in C3 and in C4 and an increase of sites under positive selection pressure in the α2 helix during the chronic stage of disease. These sites are close to CD4 and to co-receptor binding sites. We also found a negative correlation between electric charges of C3 and V4 during the late stage of disease counteracted by a positive correlation of electric charges of α2 helix and V5 during the same stage. These data allow us to hypothesize possible mechanisms of virus escape involving constant and variable regions of gp120. In particular, new mutations, including new PNGSs occurring near the CD4 and CCR5 binding sites could potentially affect receptor binding affinity and shield the virus from the immune response.

  10. Pathogenesis of highly virulent African swine fever virus in domestic pigs exposed via intraoropharyngeal, intranasopharyngeal, and intramuscular inoculation, and by direct contact with infected pigs.

    Science.gov (United States)

    Howey, Erin B; O'Donnell, Vivian; de Carvalho Ferreira, Helena C; Borca, Manuel V; Arzt, Jonathan

    2013-12-26

    To investigate the pathogenesis of African swine fever virus (ASFV), domestic pigs (n=18) were challenged with a range (10(2)-10(6) 50% hemadsorbing doses (HAD50)) of the highly virulent ASFV-Malawi strain by inoculation via the intraoropharyngeal (IOP), intranasopharyngeal (INP), or intramuscular (IM) routes. A subsequent contact challenge experiment was performed in which six IOP-inoculated donor pigs were allowed to have direct contact (DC) with six naïve pigs for exposure times that varied from 24 to 72 h. All challenge routes resulted in clinical progression and postmortem lesions similar to those previously described in experimental and natural infection. The onset of clinical signs occurred between 1 and 7 days post inoculation (dpi) and included pyrexia with variable progression to obtundation, hematochezia, melena, moribundity and death with a duration of 4-11 days. Viremia was first detected between 4 and 5 dpi in all inoculation groups whereas ASFV shedding from the nasal cavity and tonsil was first detected at 3-9 dpi. IM and DC were the most consistent modes of infection, with 12/12 (100%) of pigs challenged by these routes becoming infected. Several clinical and virological parameters were significantly different between IM and DC groups indicating dissimilarity between these modes of infection. Amongst the simulated natural routes, INP inoculation resulted in the most consistent progression of disease across the widest range of doses whilst preserving simulation of natural exposure and therefore may provide a superior system for pathogenesis and vaccine efficacy investigation.

  11. Detection of African swine fever virus DNA in blood samples stored on FTA cards from asymptomatic pigs in Mbeya region, Tanzania.

    Science.gov (United States)

    Braae, U C; Johansen, M V; Ngowi, H A; Rasmussen, T B; Nielsen, J; Uttenthal, Å

    2015-02-01

    The aim of the study was to assess whether blood samples collected onto FTA(®) cards could be used in combination with real-time PCR for the detection of African swine fever virus (ASFV) DNA in samples from resource-poor settings under the assumption that asymptomatically (sub-clinically) infected pigs may be present. Blood samples were collected from clinically healthy pigs from Mbeya Region, Tanzania. The blood samples were stored on FTA(®) cards and analysed by real-time PCR assays in duplicate; three pigs had high levels of viral DNA (Ct values of 27-29), and three pigs had a low level of viral DNA (Ct 36-45). Four pigs were positive in one of the duplicate samples only, but clear products of the expected size were obtained when the reactions were analysed by gel electrophoresis. For comparison, blood samples from pigs experimentally infected with either a pathogenic (OURT T88/1) or a non-pathogenic (OURT T88/3) isolate of ASFV were collected, stored on FTA(®) cards and analysed in the same way. The blood from pigs infected with the OURT T88/1 isolate showed high levels of viral DNA (Ct 22-33), whereas infection with non-pathogenic OURT T88/3 isolate resulted in only low levels of viral DNA (Ct 39) in samples collected at 10-14 days after inoculation.

  12. Development of African Swine Fever Virus Detection Kit%非洲猪瘟病毒检测试剂盒的研制

    Institute of Scientific and Technical Information of China (English)

    董志珍; 赵祥平; 张霞; 肖妍; 栾慎顺

    2012-01-01

    针对非洲猪瘟病毒(ASFV)P54基因建立荧光PCR检测方法,通过优化引物、TaqMan探针浓度及反应温度,研发了ASFV检测的荧光PCR检测试剂盒。经灵敏度的重复性试验及3种不同型号荧光PCR仪使用验证,所研发的试剂盒灵敏度为101copy/μL,适用于不同型号荧光PCR仪使用,可用于对非洲猪瘟病毒的快速检测。%A fluorescence polymerase chain reaction(PCR)assay was developed with ASFV p54 gene for the detection of African swine fever virus.And the ASFV fluorescent quantitative polymerase chain reaction(PCR)test kit was obtained through optimization of the primer and the fluorescence labeled TaqMan probe concentration and reaction temperature.Several snsitivity tests and verification with three different instrument models showed that,the sensitivity of kit was 101 copy/μL and suitable for different types of instrument.All these proved that the kit could be used for fast detection of ASFV.

  13. Course and transmission characteristics of oral low-dose infection of domestic pigs and European wild boar with a Caucasian African swine fever virus isolate.

    Science.gov (United States)

    Pietschmann, Jana; Guinat, Claire; Beer, Martin; Pronin, Valery; Tauscher, Kerstin; Petrov, Anja; Keil, Günther; Blome, Sandra

    2015-07-01

    In 2007, African swine fever virus (ASFV) was introduced into the Transcaucasian countries and Russia. Since then, it has spread alarmingly and reached the European Union. ASFV strains are highly virulent and lead to almost 100% mortality under experimental conditions. However, the possibility of dose-dependent disease courses has been discussed. For this reason, a study was undertaken to assess the risk of chronic disease and the establishment of carriers upon low-dose oronasal infection of domestic pigs and European wild boar. It was demonstrated that very low doses of ASFV are sufficient to infect especially weak or runted animals by the oronasal route. Some of these animals did not show clinical signs indicative of ASF, and they developed almost no fever. However, no changes were observed in individual animal regarding the onset, course and outcome of infection as assessed by diagnostic tests. After amplification of ASFV by these animals, pen- and stablemates became infected and developed acute lethal disease with similar characteristics in all animals. Thus, we found no indication of prolonged or chronic individual courses upon low-dose infection in either species. The scattered onset of clinical signs and pathogen detection within and among groups confirms moderate contagiosity that is strongly linked with blood contact. In conclusion, the prolonged course at the "herd level" together with the exceptionally low dose that proved to be sufficient to infect a runted wild boar could be important for disease dynamics in wild-boar populations and in backyard settings.

  14. Adaptive management and water temperature variability within a South African river system: what are the management options?

    Science.gov (United States)

    Rivers-Moore, N A; Jewitt, G P W

    2007-01-01

    Water temperatures, and in particular daily maximum water temperatures, are a critical water quality parameter. An understanding of associated resource management issues, including links between water temperature variability and aquatic diversity values, should be part of any management programme that considers river systems. Simple rule-based models have been shown to be appropriate tools within an adaptive management approach, both because of their heuristic value and in their application for scenario generation. Such a model was developed to simulate changes in the condition factor of Chiloglanis anoterus [Crass, R.S., 1960. Notes on the freshwater fishes of Natal with descriptions of 4 new species. Annals of the Natal Museum 14, 405-458] (Pisces: Mochokidae) in response to annual frequency of exceedance of a threshold temperature under three broad environmental scenarios for part of the Sabie River falling within South Africa's Kruger National Park. This model has potential for application within the adaptive management programme being implemented by the Kruger National Park. Results show that under broad scenarios of a 10% reduction in mean daily flow rates, or a 2 degrees C increase in mean daily air temperatures, system variability is likely to increase relative to reference conditions . It is suggested that so-called "thresholds of probable concern" (TPCs), which are based on current levels of "natural" system variability, are useful as management targets for achieving a "desired future state" for the river system. The model, recognised as a preliminary hypothesis, highlights a lack of knowledge regarding the nature of system variability, and the correspondingly wide confidence limits of the proposed TPC restricts its utility in a short-term management context. Thus, it is now recognised that its value lies more in its use as a long-term modelling tool to reflect water temperature responses to flow variability. This highlights the fact that research

  15. "Saving lives": Adapting and adopting Human Papilloma Virus (HPV) vaccination in Austria.

    Science.gov (United States)

    Paul, Katharina T

    2016-03-01

    Vaccination against the sexually transmitted Human Papilloma Virus (HPV), a necessary agent for the development of cervical cancer, has triggered much debate. In Austria, HPV policy turned from "lagging behind" in 2008 into "Europe's frontrunner" by 2013. Drawing on qualitative research, the article shows how the vaccine was transformed and made "good enough" over the course of five years. By means of tinkering and shifting storylines, policy officials and experts disassociated the vaccine from gender, vaccine manufacturers, and youth sexuality. Ultimately, the HPV vaccine functioned to strengthen the national immunization program. To this end, preventing an effective problematization of the extant screening program was essential.

  16. Human APOBEC3 induced mutation of human immunodeficiency virus type-1 contributes to adaptation and evolution in natural infection.

    Directory of Open Access Journals (Sweden)

    Eun-Young Kim

    2014-07-01

    Full Text Available Human APOBEC3 proteins are cytidine deaminases that contribute broadly to innate immunity through the control of exogenous retrovirus replication and endogenous retroelement retrotransposition. As an intrinsic antiretroviral defense mechanism, APOBEC3 proteins induce extensive guanosine-to-adenosine (G-to-A mutagenesis and inhibit synthesis of nascent human immunodeficiency virus-type 1 (HIV-1 cDNA. Human APOBEC3 proteins have additionally been proposed to induce infrequent, potentially non-lethal G-to-A mutations that make subtle contributions to sequence diversification of the viral genome and adaptation though acquisition of beneficial mutations. Using single-cycle HIV-1 infections in culture and highly parallel DNA sequencing, we defined trinucleotide contexts of the edited sites for APOBEC3D, APOBEC3F, APOBEC3G, and APOBEC3H. We then compared these APOBEC3 editing contexts with the patterns of G-to-A mutations in HIV-1 DNA in cells obtained sequentially from ten patients with primary HIV-1 infection. Viral substitutions were highest in the preferred trinucleotide contexts of the edited sites for the APOBEC3 deaminases. Consistent with the effects of immune selection, amino acid changes accumulated at the APOBEC3 editing contexts located within human leukocyte antigen (HLA-appropriate epitopes that are known or predicted to enable peptide binding. Thus, APOBEC3 activity may induce mutations that influence the genetic diversity and adaptation of the HIV-1 population in natural infection.

  17. The ongoing development of a pragmatic and adaptive fire management policy in a large African savanna protected area.

    Science.gov (United States)

    van Wilgen, Brian W; Govender, Navashni; Smit, Izak P J; MacFadyen, Sandra

    2014-01-01

    This paper describes recent changes to the fire management policy of the 1.9 million ha Kruger National Park in South Africa. It provides a real-life example of adaptive learning in an environment where understanding is incomplete, but where management nonetheless has to proceed. The previous policy called for the application of fire to meet burnt area targets that were set for administrative subdivisions, and that were assessed at the scale of the entire park. This was problematic because the park is large and heterogeneous, and because sound ecological motivations that could link burning prescriptions to ecological objectives were missing. The new policy divides the park into five fire management zones on the basis of differences in mean annual rainfall, historic fire return periods, and geology. In addition, it proposes fire management actions designed to achieve specified ecological objectives in each zone, and includes fire-regime related thresholds and associated ecological outcomes against which to assess the effectiveness of management. The new policy is an improvement over previous iterations, but several challenges remain. Most important among these would be to continually improve the understanding of the effects of fire, and to develop frameworks for assessing the impacts of fire together with other ecosystem drivers that interact strongly with fire to influence the attainment of ecological objectives.

  18. Dengue virus type 3 adaptive changes during epidemics in Sao Jose de Rio Preto, Brazil, 2006-2007.

    Directory of Open Access Journals (Sweden)

    Christian Julian Villabona-Arenas

    Full Text Available Global dengue virus spread in tropical and sub-tropical regions has become a major international public health concern. It is evident that DENV genetic diversity plays a significant role in the immunopathology of the disease and that the identification of polymorphisms associated with adaptive responses is important for vaccine development. The investigation of naturally occurring genomic variants may play an important role in the comprehension of different adaptive strategies used by these mutants to evade the human immune system. In order to elucidate this role we sequenced the complete polyprotein-coding region of thirty-three DENV-3 isolates to characterize variants circulating under high endemicity in the city of São José de Rio Preto, Brazil, during the onset of the 2006-07 epidemic. By inferring the evolutionary history on a local-scale and estimating rates of synonymous (dS and nonsynonimous (dN substitutions, we have documented at least two different introductions of DENV-3 into the city and detected 10 polymorphic codon sites under significant positive selection (dN/dS > 1 and 8 under significant purifying selection (dN/dS < 1. We found several polymorphic amino acid coding sites in the envelope (15, NS1 (17, NS2A (11, and NS5 (24 genes, which suggests that these genes may be experiencing relatively recent adaptive changes. Furthermore, some polymorphisms correlated with changes in the immunogenicity of several epitopes. Our study highlights the existence of significant and informative DENV variability at the spatio-temporal scale of an urban outbreak.

  19. Consumption of Sutherlandia frutescens by HIV-Seropositive South African Adults: An Adaptive Double-Blind Randomized Placebo Controlled Trial.

    Directory of Open Access Journals (Sweden)

    Douglas Wilson

    Full Text Available Sutherlandia frutescens (L. R. Br. is widely used as an over the counter complementary medicine and in traditional medications by HIV seropositive adults living in South Africa; however the plant's safety has not been objectively studied. An adaptive two-stage randomized double-blind placebo controlled study was used to evaluate the safety of consuming dried S. frutescens by HIV seropositive adults with CD4 T-lymphocyte count of >350 cells/μL.In Stage 1 56 participants were randomized to S. frutescens 400, 800 or 1,200 mg twice daily or matching placebo for 24 weeks. In Stage 2 77 additional participants were randomized to either 1,200 mg S. frutescens or placebo. In the final analysis data from Stage 1 and Stage 2 were combined such that 107 participants were analysed (54 in the S. frutescens 1,200 mg arm and 53 in the placebo arm.S. frutescens did not change HIV viral load, and CD4 T-lymphocyte count was similar in the two arms at 24 weeks; however, mean and total burden of infection (BOI; defined as days of infection-related events in each participant was greater in the S. frutescens arm: mean (SD 5.0 (5.5 vs. 9.0 (12.7 days (p = 0.045, attributed to two tuberculosis cases in subjects taking isoniazid preventive therapy (IPT.A possible interaction between S. frutescens and IPT needs further evaluation, and may presage antagonistic interactions with other herbs having similar biochemical (antioxidant properties. No other safety issues relating to consumption of S. frutescens in this cohort were identified.ClinicalTrials.gov NCT00549523.

  20. Influence of host resistance on viral adaptation: hepatitis C virus as a case study

    OpenAIRE

    Plauzolles A; Lucas M; Gaudieri S

    2015-01-01

    Anne Plauzolles,1 Michaela Lucas,2,3 Silvana Gaudieri41Centre for Forensic Science, 2School of Medicine and Pharmacology, Harry Perkins Institute, 3School of Pathology and Laboratory Medicine, 4School of Anatomy, Physiology and Human Biology, University of Western Australia, Perth, WA, AustraliaAbstract: Genetic and cellular studies have shown that the host's innate and adaptive immune responses are an important correlate of viral infection outcome. The features of the host's ...

  1. Mapping of amino acid residues responsible for adhesion of cell culture-adapted foot-and-mouth disease SAT type viruses.

    Science.gov (United States)

    Maree, Francois F; Blignaut, Belinda; de Beer, Tjaart A P; Visser, Nico; Rieder, Elizabeth A

    2010-10-01

    Foot-and-mouth disease virus (FMDV) infects host cells by adhering to the alpha(V) subgroup of the integrin family of cellular receptors in a Arg-Gly-Asp (RGD) dependent manner. FMD viruses, propagated in non-host cell cultures are reported to acquire the ability to enter cells via alternative cell surface molecules. Sequencing analysis of SAT1 and SAT2 cell culture-adapted variants showed acquisition of positively charged amino acid residues within surface-exposed loops of the outer capsid structural proteins. The fixation of positively charged residues at position 110-112 in the beta F-beta G loop of VP1 of SAT1 isolates is thought to correlate with the acquisition of the ability to utilise alternative glycosaminoglycan (GAG) molecules for cell entry. Similarly, two SAT2 viruses that adapted readily to BHK-21 cells accumulated positively charged residues at positions 83 and 85 of the beta D-beta E loop of VP1. Both regions surround the fivefold axis of the virion. Recombinant viruses containing positively charged residues at position 110 and 112 of VP1 were able to infect CHO-K1 cells (that expresses GAG) and demonstrated increased infectivity in BHK-21 cells. Therefore, recombinant SAT viruses engineered to express substitutions that induce GAG-binding could be exploited in the rational design of vaccine seed stocks with improved growth properties in cell cultures.

  2. Characterization of homologous and heterologous adaptive immune responses in porcine reproductive and respiratory syndrome virus infection

    Directory of Open Access Journals (Sweden)

    Díaz Ivan

    2012-04-01

    Full Text Available Abstract The present study characterized the homologous and heterologous immune response in type-I porcine reproductive and respiratory syndrome virus (PRRSV infection. Two experiments were conducted: in experiment 1, eight pigs were inoculated with PRRSV strain 3262 and 84 days post-inoculation (dpi they were challenged with either strain 3262 or strain 3267 and followed for the next 14 days (98 dpi. In experiment 2, eight pigs were inoculated with strain 3267 and challenged at 84 dpi as above. Clinical course, viremia, humoral response (neutralizing and non-neutralizing antibodies, NA and virus-specific IFN-γ responses (ELISPOT were evaluated all throughout the study. Serum levels of IL-1, IL-6, IL-8, TNF-α and TGF-β were determined (ELISA after the second challenge. In experiment 1 primo-inoculation with strain 3262 induced viremia of ≤ 28 days, low titres of homologous NA but strong IFN-γ responses. In contrast, strain 3267 induced longer viremias (up to 56 days, higher NA titres (≤ 6 log2 and lower IFN-γ responses. Inoculation with 3267 produced higher serum IL-8 levels. After the re-challenge at 84 dpi, pigs in experiment 1 developed mostly a one week viremia regardless of the strain used. In experiment 2, neither the homologous nor the heterologous challenge resulted in detectable viremia although PRRSV was present in tonsils of some animals. Homologous re-inoculation with 3267 produced elevated TGF-β levels in serum for 7–14 days but this did not occur with the heterologous re-inoculation. In conclusion, inoculation with different PRRSV strains result in different virological and immunological outcomes and in different degrees of homologous and heterologous protection.

  3. ALV-J GP37 molecular analysis reveals novel virus-adapted sites and three tyrosine-based Env species.

    Directory of Open Access Journals (Sweden)

    Jianqiang Ye

    Full Text Available Compared to other avian leukosis viruses (ALV, ALV-J primarily induces myeloid leukemia and hemangioma and causes significant economic loss for the poultry industry. The ALV-J Env protein is hypothesized to be related to its unique pathogenesis. However, the molecular determinants of Env for ALV-J pathogenesis are unclear. In this study, we compared and analyzed GP37 of ALV-J Env and the EAV-HP sequence, which has high homology to that of ALV-J Env. Phylogenetic analysis revealed five groups of ALV-J GP37 and two novel ALV-J Envs with endemic GP85 and EAV-HP-like GP37. Furthermore, at least 15 virus-adapted mutations were detected in GP37 compared to the EAV-HP sequence. Further analysis demonstrated that three tyrosine-based motifs (YxxM, ITIM (immune tyrosine-based inhibitory motif and ITAM-like (immune tyrosine-based active motif like associated with immune disease and oncogenesis were found in the cytoplasmic tail of GP37. Based on the potential function and distribution of these motifs in GP37, ALV-J Env was grouped into three species, inhibitory Env, bifunctional Env and active Env. Accordingly, 36.91%, 61.74% and 1.34% of ALV-J Env sequences from GenBank are classified as inhibitory, bifunctional and active Env, respectively. Additionally, the Env of the ALV-J prototype strain, HPRS-103, and 17 of 18 EAV-HP sequences belong to the inhibitory Env. And models for signal transduction of the three ALV-J Env species were predicted. Our findings and models provide novel insights for identifying the roles and molecular mechanism of ALV-J Env in the unique pathogenesis of ALV-J.

  4. ALV-J GP37 molecular analysis reveals novel virus-adapted sites and three tyrosine-based Env species.

    Science.gov (United States)

    Ye, Jianqiang; Fan, Zhonglei; Shang, Jianjun; Tian, Xiaoyan; Yang, Jialiang; Chen, Hongjun; Shao, Hongxia; Qin, Aijian

    2015-01-01

    Compared to other avian leukosis viruses (ALV), ALV-J primarily induces myeloid leukemia and hemangioma and causes significant economic loss for the poultry industry. The ALV-J Env protein is hypothesized to be related to its unique pathogenesis. However, the molecular determinants of Env for ALV-J pathogenesis are unclear. In this study, we compared and analyzed GP37 of ALV-J Env and the EAV-HP sequence, which has high homology to that of ALV-J Env. Phylogenetic analysis revealed five groups of ALV-J GP37 and two novel ALV-J Envs with endemic GP85 and EAV-HP-like GP37. Furthermore, at least 15 virus-adapted mutations were detected in GP37 compared to the EAV-HP sequence. Further analysis demonstrated that three tyrosine-based motifs (YxxM, ITIM (immune tyrosine-based inhibitory motif) and ITAM-like (immune tyrosine-based active motif like)) associated with immune disease and oncogenesis were found in the cytoplasmic tail of GP37. Based on the potential function and distribution of these motifs in GP37, ALV-J Env was grouped into three species, inhibitory Env, bifunctional Env and active Env. Accordingly, 36.91%, 61.74% and 1.34% of ALV-J Env sequences from GenBank are classified as inhibitory, bifunctional and active Env, respectively. Additionally, the Env of the ALV-J prototype strain, HPRS-103, and 17 of 18 EAV-HP sequences belong to the inhibitory Env. And models for signal transduction of the three ALV-J Env species were predicted. Our findings and models provide novel insights for identifying the roles and molecular mechanism of ALV-J Env in the unique pathogenesis of ALV-J.

  5. Increase in chemokines CXCL10 and CCL2 in blood from pigs infected with high compared to low virulence African swine fever virus isolates.

    Science.gov (United States)

    Fishbourne, Emma; Hutet, Evelyne; Abrams, Charles; Cariolet, Roland; Le Potier, Marie-Frédérique; Takamatsu, Haru-H; Dixon, Linda K

    2013-10-01

    Modulation of the expression of chemokines and chemokine receptors in whole blood was compared following infection of pigs with high and low virulence isolates of African swine fever virus. Levels of mRNAs for CCL2, CCL3L1, CCL4, CXCL10, CCR1 and CCR5 were significantly increased in at least one time point following infection in two experiments and CCL5, CCR9 and CXCR4 mRNA were significantly increased in one of the experiments. The results showed that greatest fold increases in mRNAs for CXCL10 and CCL2 were observed following infection of pigs. CXCL10 mRNA was increased by up to 15 fold in infected compared to uninfected pigs. CXCL10 protein was also detected in serum from pigs infected with the high virulence Benin 97/1 isolate. Levels of CCL2 mRNA were increased in pigs infected with high virulence Benin 97/1 isolate compared to low virulence OURT88/3 isolate and this correlated with an increase of greater than 30 fold in levels of CCL2 protein detected in serum from pigs infected with this isolate. An increase in overall chemotaxis active compounds in defibrinated plasma samples from Benin 97/1 infected pigs was observed at 3 days post-infection (dpi) and a decrease by 7 dpi as measured by chemotaxis assay using normal pig leucocytes in vitro. Increased levels of CXCL10 may either contribute to the activation of lymphocyte priming toward the Th1 phenotype or induction of T lymphocyte apoptosis. Increased levels of CCL2, a chemoattractant for macrophages, may result in increased recruitment of monocytes from bone marrow thus increasing the pool of cells susceptible to infection.

  6. Immune-driven adaptation of hepatitis B virus genotype D involves preferential alteration in B-cell epitopes and replicative attenuation--an insight from human immunodeficiency virus/hepatitis B virus coinfection.

    Science.gov (United States)

    Mondal, R K; Khatun, M; Ghosh, S; Banerjee, P; Datta, S; Sarkar, S; Saha, B; Santra, A; Banerjee, S; Chowdhury, A; Datta, S

    2015-07-01

    An important driving force behind the sequence diversity of hepatitis B virus (HBV) is viral adaptation to host immune responses. To gain an insight into the impact of host immunity on genetic diversification and properties of HBV, we characterized HBV of genotype D from treatment-naive hepatitis B e antigen-positive (EP) and hepatitis B e antigen-negative (EN) patients with chronic hepatitis B (CHB), where HBV is under stronger immune pressure, with that of HBV derived from human immunodeficiency virus (HIV)/HBV-coinfected individuals, where HIV infection has significantly weakened the immune system. Full-length sequence analysis showed that HBV heterogeneity was most extensive in EN-CHB followed by EP-CHB and HIV/HBV coinfection. The relative magnitude of non-synonymous changes within B-cell epitopes was greater than that in T-cell epitopes of HBV open reading frames (ORFs) in both EP-CHB and EN-CHB. Nine amino acid substitutions were identified in B-cell epitopes and one in a T-cell epitope of HBV in EN-CHB, most of which resulted in altered hydrophobicities, as determined using the Kyte and Doolittle method, relative to wild-type residues found in HBV from the HIV-positive group. Additionally, 19 substitutions occurred at significantly higher frequencies in non-epitope regions of HBV ORF-P in EN-CHB than HIV/HBV-coinfected patients. In vitro replication assay demonstrated that the substitutions, particularly in reverse transcriptase and RNaseH domains of ORF-P, resulted in a decline in replication capacity of HBV. Hence, our results indicate that HBV adapts to increasing immune pressure through preferential mutations in B-cell epitopes and by replicative attenuation. The viral epitopes linked to immune response identified in this study bear important implications for future HBV vaccine studies.

  7. African Literature

    OpenAIRE

    Recek, Denis

    2011-01-01

    The topic of this diploma is the formation and shaping of African literature. The first chapter is about the beginning of African literature. It describes oral literature and its transmission into written literature. Written African literature had great problems in becoming a part of world literature because of its diversity of languages and dialects. Christianity and Islam are mentioned as two religions which had a great impact on African literature. Colonialism is broadly described as an es...

  8. Benefiting Africans

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Along with thriving Sino-African economic and trade ties,Chinese companies have attached greater importance to their social responsibility to Africans.More than 2,000 sweaters woven by Chinese mothers were sent to orphans and disabled children in Kenya and four other African countries in September. This activity was launched by Hengyuanxiang,aleading Chinese wool manufacturer.

  9. Benefiting Africans

    Institute of Scientific and Technical Information of China (English)

    ZHANG ZHIPING

    2011-01-01

    Along with thriving Sino-African economic and trade ties,Chinese companies have attached greater importance to their social responsibility to Africans.More than 2,000 sweaters woven by Chinese mothers were sent to orphans and disabled children in Kenya and four other African countries in September.This activity was launched by Hengyuanxiang,a leading Chinese wool manufacturer.

  10. The prevalence of hepatitis B virus markers in a cohort of students in Bangui, Central African Republic

    Directory of Open Access Journals (Sweden)

    Béré Aubin

    2010-07-01

    Full Text Available Abstract Background Hepatitis B virus (HBV is the major cause of chronic hepatitis, cirrhosis, and hepatocellular carcinoma. The global epidemiological scenario of HBV infection has been changing rapidly over the last two decades due to an effective immunization programme initiated by the World Health Organization. The objective of this study is to estimate the prevalence of HBV in apparently healthy young people and to identify the risk factors of transmission of the HBV among this population in Bangui. Methods Dried blood Spots from 801 adolescent high school and young adult university students were prepared by spotting a drop of whole blood (4 spots from the same fingerprick onto Whatman filter paper. A blood sample aliquot eluted from DBS was then processed with commercial ELISA tests (Abbott Murex, Dartfort, UK to detect HBsAg antigen, Anti-HBc and Anti-HBs antibodies. Results The overall prevalence was 42.3% for antibody to hepatitis B core antigen, 15.5% for HBsAg of which 1.3% of HBsAg alone. HBV familial antecedents, sexual activity and socioeconomic conditions were the main risk factors of HBV infection encountered in the adolescents and young adults. Conclusion These results show for the first time the high prevalence of HBV in apparently healthy young people in Bangui. This high prevalence is age- and sex-independent. Transmission risk factors were a familial antecedent of HBV, no utilisation of condoms and public scholarship. To lower HBV prevalence, an adequate program of active screening and vaccination for adolescents and young adults should be implemented, along with a universal immunization program.

  11. Chlamydia trachomatis, human immunodeficiency virus (HIV distribution and sexual behaviors across gender and age group in an African setting.

    Directory of Open Access Journals (Sweden)

    Joel Fleury Djoba Siawaya

    Full Text Available OBJECTIVE: The purpose of this study was to (1 describe the distribution of Chlamydia trachomatis (CT and Human Immunodeficiency Virus (HIV cases across gender and age groups in Libreville (Gabon; (2 examine Gabonese Sexually Transmitted Infections (STIs-related risk behaviour. METHODS: The sampled population was people attending the "Laboratoire National de Santé Plublique". Between 2007 and 2011, 14 667 and 9 542 people respectively, were tested for CT and HIV infections. 1 854 of them were tested for both infections. We calculated CT and HIV rates across gender and age groups. Also analysed was the groups' contribution to the general CT and HIV epidemiology. STIs-related risk behaviours were assessed in 224 men and 795 women (between July 2011 and March 2013 who agreed and answered a questionnaire including questions on their marital status, number of sex partners, sexual practices, history of STIs, sex frequency and condom use. RESULTS: Data showed a 24% dropped in the CT infection rate between 2007 and 2010, followed by a 14% increase in 2011. The HIV infection rates for the same period were between 15% and 16%. The risk of a CT-positive subject getting HIV is about 0.71 times the risk of a CT-negative subject. Young adult aged between 18 and 35 years old represented 65.2% of people who had STIs. 80% of women and 66% of men confessed to an inconsistent use of condoms. 11.6% of women and 48% of men declared having multiple sex partners. 61% of questioned women and 67% of men declared knowing their HIV status. CONCLUSIONS: In this Gabonese setting, the population-aged from 18 to 35 years is the most affected by STIs. Other matters of concern are the inconsistent use of protection and sex with non-spousal or non-life partners.

  12. Identification of adaptive mutations in the influenza A virus non-structural 1 gene that increase cytoplasmic localization and differentially regulate host gene expression.

    Directory of Open Access Journals (Sweden)

    Nicole Forbes

    Full Text Available The NS1 protein of influenza A virus (IAV is a multifunctional virulence factor. We have previously characterized gain-of-function mutations in the NS1 protein arising from the experimental adaptation of the human isolate A/Hong Kong/1/1968(H3N2 (HK to the mouse. The majority of these mouse adapted NS1 mutations were demonstrated to increase virulence, viral fitness, and interferon antagonism, but differ in binding to the post-transcriptional processing factor cleavage and polyadenylation specificity factor 30 (CPSF30. Because nuclear trafficking is a major genetic determinant of influenza virus host adaptation, we assessed subcellular localization and host gene expression of NS1 adaptive mutations. Recombinant HK viruses with adaptive mutations in the NS1 gene were assessed for NS1 protein subcellular localization in mouse and human cells using confocal microscopy and cellular fractionation. In human cells the HK wild-type (HK-wt virus NS1 protein partitioned equivalently between the cytoplasm and nucleus but was defective in cytoplasmic localization in mouse cells. Several adaptive mutations increased the proportion of NS1 in the cytoplasm of mouse cells with the greatest effects for mutations M106I and D125G. The host gene expression profile of the adaptive mutants was determined by microarray analysis of infected mouse cells to show either high or low extents of host-gene regulation (HGR or LGR phenotypes. While host genes were predominantly down regulated for the HGR group of mutants (D2N, V23A, F103L, M106I+L98S, L98S, M106V, and M106V+M124I, the LGR phenotype mutants (D125G, M106I, V180A, V226I, and R227K were characterized by a predominant up regulation of host genes. CPSF30 binding affinity of NS1 mutants did not predict effects on host gene expression. To our knowledge this is the first report of roles of adaptive NS1 mutations that impact intracellular localization and regulation of host gene expression.

  13. Efficient Culture Adaptation of Hepatitis C Virus Recombinants with Genotype-Specific Core-NS2 by Using Previously Identified Mutations

    DEFF Research Database (Denmark)

    Scheel, Troels Kasper Høyer; Gottwein, Judith M; Carlsen, Thomas H R;

    2011-01-01

    ) but not to ED43 (4a). The mutations permitting robust virus production in Huh7.5 cells had no apparent effect on viral replication but allowed efficient assembly of intracellular infectious HCV for adapted novel or previously developed recombinants. In conclusion, previously identified mutations permitted......Hepatitis C virus (HCV) is an important cause of chronic liver disease, and interferon-based therapy cures only 40 to 80% of patients, depending on HCV genotype. Research was accelerated by genotype 2a (strain JFH1) infectious cell culture systems. We previously developed viable JFH1-based...... recombinants encoding the structural proteins (core, E1, E2), p7, and NS2 of prototype isolates of the seven major HCV genotypes; most recombinants required adaptive mutations. To enable genotype-, subtype-, and isolate-specific studies, we developed efficient core-NS2 recombinants from additional genotype 1a...

  14. Isolation and adaptation of bovine herpes virus Type 1 in embryonated chicken eggs and in Madin–Darby bovine kidney cell line

    Science.gov (United States)

    Samrath, Devprabha; Shakya, Sanjay; Rawat, Nidhi; Gilhare, Varsha Rani; Singh, Fateh

    2016-01-01

    Aim: Objective of the present study was to isolate bovine herpes virus Type 1 (BHV-1) from semen of infected bull and to adapt it onto embryonated eggs and Madin–Darby bovine kidney (MDBK) cell line. Further, the virus was identified by agar gel immunodiffusion (AGID) test. Materials and Methods: Semen samples were collected from five BHV-1 positive bulls previously confirmed for the presence of antibodies against BHV-1 using avidin-biotin enzyme linked immunosorbent assay test. The virus from semen samples was adapted in chorioallantoic membrane (CAM) of 11-day-old embryonated chickens eggs and in MDBK cell line. The presence of BHV-1 in infected CAM and cell culture fluid was confirmed by AGID test. Results: Virus infected CAM showed edema, congestion and thickening at first passage level. Small foci ranged from 1 to 2 mm in diameter, scattered all over the membrane were observed at first passage. More severe changes were observed in CAM after serial passaging. The large pock lesions, round in shape with opaque raised edge and depressed gray central area of necrosis ranged from 3 to 5 mm in diameter were developed at fourth passage. Blind passages in MDBK cell culture were made. The MDBK cell line at second passage level showed characteristic cytopathic effect viz. rounding of cells with shrinkage, followed by aggregation or clumping of cells which progressed rapidly and appeared as “bunch of grapes” at 72 h post inoculation. Few cells become elongated when compared with uninfected controls. A homogenate of CAM with distinct pock lesions and infected cell culture fluid developed precipitation line within 48 h against specific anti-BHV-1 immune serum by AGID test. Conclusion: BHV-1 was easily adapted in CAM of chicken embryos and in MDBK cell line. Virus infected CAM and cell culture fluid showed precipitin band by AGID test. PMID:27051213

  15. Isolation and adaptation of bovine herpes virus Type 1 in embryonated chicken eggs and in Madin–Darby bovine kidney cell line

    Directory of Open Access Journals (Sweden)

    Devprabha Samrath

    2016-02-01

    Full Text Available Aim: Objective of the present study was to isolate bovine herpes virus Type 1 (BHV-1 from semen of infected bull and to adapt it onto embryonated eggs and Madin–Darby bovine kidney (MDBK cell line. Further, the virus was identified by agar gel immunodiffusion (AGID test. Materials and Methods: Semen samples were collected from five BHV-1 positive bulls previously confirmed for the presence of antibodies against BHV-1 using avidin-biotin enzyme linked immunosorbent assay test. The virus from semen samples was adapted in chorioallantoic membrane (CAM of 11-day-old embryonated chickens eggs and in MDBK cell line. The presence of BHV-1 in infected CAM and cell culture fluid was confirmed by AGID test. Results: Virus infected CAM showed edema, congestion and thickening at first passage level. Small foci ranged from 1 to 2 mm in diameter, scattered all over the membrane were observed at first passage. More severe changes were observed in CAM after serial passaging. The large pock lesions, round in shape with opaque raised edge and depressed gray central area of necrosis ranged from 3 to 5 mm in diameter were developed at fourth passage. Blind passages in MDBK cell culture were made. The MDBK cell line at second passage level showed characteristic cytopathic effect viz. rounding of cells with shrinkage, followed by aggregation or clumping of cells which progressed rapidly and appeared as “bunch of grapes” at 72 h post inoculation. Few cells become elongated when compared with uninfected controls. A homogenate of CAM with distinct pock lesions and infected cell culture fluid developed precipitation line within 48 h against specific anti-BHV-1 immune serum by AGID test. Conclusion: BHV-1 was easily adapted in CAM of chicken embryos and in MDBK cell line. Virus infected CAM and cell culture fluid showed precipitin band by AGID test.

  16. Adaptive mutations allow establishment of JFH1-based cell culture systems for hepatitis C virus genotype 4A

    DEFF Research Database (Denmark)

    2013-01-01

    transmembrane domain (.alpha.), in the cytoplasmic part (.beta.) or at the NS2/NS3 cleavage site (y). Following transfection of Huh7.5 cells with RNA transcripts, infectious viruses were produced in the ED43/JFH1-.beta. and -y cultures only. Compared to the 2a control virus, production of infectious viruses...

  17. [African swine fever in Russian Federation].

    Science.gov (United States)

    Zaberezhnyĭ, A D; Aliper, T I; Grebennikova, T A; Verkhovskiĭ, O A; Sanchez-Vizcaino, J M; Mur, Lina; Nepoklonov, E A; L'vov, D K

    2012-01-01

    African swine fever (ASF) is an infectious viral disease that causes high economic losses due to the necessity of depopulation of pigs in affected areas, sanitary measures, trade restrictions, etc. The virus (ASFV) is relatively stable in the unprocessed meat products and environment. Thus, large areas are at risk due to free movement of people and products. The ASFV does not affect people and animals, except the wild and domestic pigs. Some ticks can become infected and carry the virus for years. Adaptation of the virus by changing into the less virulent form would mean the threat of an endemic situation to the area. The disease is endemic in domestic and wild pigs in most of sub-Saharan Africa and Sardinia, Italy. There is no treatment for ASF, and no vaccine has been developed. In case of infection with less virulent ASFV strains, the recovered pigs could spread the virus as long as their live. In terms of clinical symptoms, ASF is very similar to Classical Swine Fever. The methods of laboratory diagnostics are well developed and efficient for identification of ASFV and virus-specific antibodies. Experience of eradication of ASF in Spain suggests the importance of serological monitoring of pigs. In the spring of 2007, the ASF was detected in the Caucasus region. Same virus was detected in Georgia, Armenia, Azerbaijan, and Russia. The ASFV circulating in the Caucasus and the Russian Federation is a highly virulent virus. No reduction of the virulence was observed since the first outbreak in Georgia. In the last years, the ASF remained in the Caucasus, southern parts of Russia and appeared occasionally as far as St. Petersburg and St. Petersburg region, and in the area of Nizhny Novgorod. Domestic pigs play an important role in the ASFV spread; they transfer the virus to the wild boars. The virus circulates in the population of wild boars depending on their density in the area. Occasionally, the disease is spread from wild to domestic pigs. There is no evidence of

  18. Rapid acquisition of polymorphic virulence markers during adaptation of highly pathogenic avian influenza H5N8 virus in the mouse

    Science.gov (United States)

    Choi, Won-Suk; Baek, Yun Hee; Kwon, Jin Jung; Jeong, Ju Hwan; Park, Su-Jin; Kim, Young-il; Yoon, Sun-Woo; Hwang, Jungwon; Kim, Myung Hee; Kim, Chul-Joong; Webby, Richard J.; Choi, Young Ki; Song, Min-Suk

    2017-01-01

    Emergence of a highly pathogenic avian influenza (HPAI) H5N8 virus in Asia and its spread to Europe and North America has caused great concern for human health. Although the H5N8 virus has been only moderately pathogenic to mammalian hosts, virulence can still increase. We evaluated the pathogenic potential of several H5N8 strains via the mouse-adaptation method. Two H5N8 viruses were sequentially passaged in BALB/c mice and plaque-purified from lung samples. The viruses rapidly obtained high virulence (MLD50, up to 0.5 log10 PFU/mL) within 5 passages. Sequence analysis revealed the acquisition of several virulence markers, including the novel marker P708S in PB1 gene. Combinations of markers synergistically enhanced viral replication and polymerase activity in human cell lines and virulence and multiorgan dissemination in mice. These results suggest that H5N8 viruses can rapidly acquire virulence markers in mammalian hosts; thus, rapid spread as well as repeated viral introduction into the hosts may significantly increase the risk of human infection and elevate pandemic potential. PMID:28094780

  19. Pre-Clinical Evaluation of a Real-Time PCR Assay on a Portable Instrument as a Possible Field Diagnostic Tool: Experiences from the Testing of Clinical Samples for African and Classical Swine Fever Viruses.

    Science.gov (United States)

    Liu, L; Luo, Y; Accensi, F; Ganges, L; Rodríguez, F; Shan, H; Ståhl, K; Qiu, H-J; Belák, S

    2016-06-16

    African swine fever (ASF) and classical swine fever (CSF) are two highly infectious transboundary animal diseases (TADs) that are serious threats to the pig industry worldwide, including in China, the world's largest pork producer. In this study, a duplex real-time PCR assay was developed for the rapid detection and differentiation of African swine fever virus (ASFV) and classical swine fever virus (CSFV). The assay was performed on a portable, battery-powered PCR thermocycler with a low sample throughput (termed as 'T-COR4 assay'). The feasibility and reliability of the T-COR4 assay as a possible field method was investigated by testing clinical samples collected in China. When evaluated with reference materials or samples from experimental infections, the assay performed in a reliable manner, producing results comparable to those obtained from stationary PCR platforms. Of 59 clinical samples, 41 had results identical to a two-step CSFV real-time PCR assay. No ASFV was detected in these samples. The T-COR4 assay was technically easy to perform and produced results within 3 h, including sample preparation. In combination with a simple sample preparation method, the T-COR4 assay provides a new tool for the field diagnosis and differentiation of ASF and CSF, which could be of particular value in remote areas.

  20. Adaptation of human immunodeficiency virus type 1 to cells expressing a binding-deficient CD4 mutant (lysine 46 to aspartic acid).

    Science.gov (United States)

    Choe, H R; Sodroski, J

    1995-01-01

    Human immunodeficiency virus (HIV-1) was adapted to replicate efficiently in cells expressing an altered form of the CD4 viral receptor. The mutant CD4 (46 K/D) contained a single amino acid change (lysine 46 to aspartic acid) in the CDR2 loop of domain 1, which results in a 15-fold reduction in affinity for the viral gp120 glycoprotein. The ability of the adapted virus to replicate in CD4 46 K/D-expressing cells was independently enhanced by single amino acid changes in the V2 variable loop, the V3 variable loop, and the fourth conserved (C4) region of the gp120 glycoprotein. Combinations of these amino acids in the same envelope glycoprotein resulted in additive enhancement of virus replication in cells expressing the CD4 46 K/D molecule. In cells expressing the wild-type CD4 glycoproteins, the same V2 and V3 residue changes also increased the efficiency of replication of a virus exhibiting decreased receptor-binding ability due to an amino acid change (aspartic acid 368 to glutamic acid) in the gp120 glycoprotein. In neither instance did the adaptive changes restore the binding ability of the monomeric gp120 glycoprotein or the oligomeric envelope glycoprotein complex for the mutant or wild-type CD4 glycoproteins, respectively. Thus, particular conformations of the gp120 V2 and V3 variable loops and of the C4 region allow postreceptor binding events in the membrane fusion process to occur in the context of less than optimal receptor binding. These results suggest that the fusion-related functions of the V2, V3, and C4 regions of gp120 are modulated by CD4 binding. PMID:7707502

  1. Clinical Sequencing Uncovers Origins and Evolution of Lassa Virus.

    Science.gov (United States)

    Andersen, Kristian G; Shapiro, B Jesse; Matranga, Christian B; Sealfon, Rachel; Lin, Aaron E; Moses, Lina M; Folarin, Onikepe A; Goba, Augustine; Odia, Ikponmwonsa; Ehiane, Philomena E; Momoh, Mambu; England, Eleina M; Winnicki, Sarah; Branco, Luis M; Gire, Stephen K; Phelan, Eric; Tariyal, Ridhi; Tewhey, Ryan; Omoniwa, Omowunmi; Fullah, Mohammed; Fonnie, Richard; Fonnie, Mbalu; Kanneh, Lansana; Jalloh, Simbirie; Gbakie, Michael; Saffa, Sidiki; Karbo, Kandeh; Gladden, Adrianne D; Qu, James; Stremlau, Matthew; Nekoui, Mahan; Finucane, Hilary K; Tabrizi, Shervin; Vitti, Joseph J; Birren, Bruce; Fitzgerald, Michael; McCowan, Caryn; Ireland, Andrea; Berlin, Aaron M; Bochicchio, James; Tazon-Vega, Barbara; Lennon, Niall J; Ryan, Elizabeth M; Bjornson, Zach; Milner, Danny A; Lukens, Amanda K; Broodie, Nisha; Rowland, Megan; Heinrich, Megan; Akdag, Marjan; Schieffelin, John S; Levy, Danielle; Akpan, Henry; Bausch, Daniel G; Rubins, Kathleen; McCormick, Joseph B; Lander, Eric S; Günther, Stephan; Hensley, Lisa; Okogbenin, Sylvanus; Schaffner, Stephen F; Okokhere, Peter O; Khan, S Humarr; Grant, Donald S; Akpede, George O; Asogun, Danny A; Gnirke, Andreas; Levin, Joshua Z; Happi, Christian T; Garry, Robert F; Sabeti, Pardis C

    2015-08-13

    The 2013-2015 West African epidemic of Ebola virus disease (EVD) reminds us of how little is known about biosafety level 4 viruses. Like Ebola virus, Lassa virus (LASV) can cause hemorrhagic fever with high case fatality rates. We generated a genomic catalog of almost 200 LASV sequences from clinical and rodent reservoir samples. We show that whereas the 2013-2015 EVD epidemic is fueled by human-to-human transmissions, LASV infections mainly result from reservoir-to-human infections. We elucidated the spread of LASV across West Africa and show that this migration was accompanied by changes in LASV genome abundance, fatality rates, codon adaptation, and translational efficiency. By investigating intrahost evolution, we found that mutations accumulate in epitopes of viral surface proteins, suggesting selection for immune escape. This catalog will serve as a foundation for the development of vaccines and diagnostics. VIDEO ABSTRACT.

  2. Adaptive mutations allow establishment of JFH1-based cell culture systems for hepatitis C virus genotype 4A

    DEFF Research Database (Denmark)

    2013-01-01

    transmembrane domain (.alpha.), in the cytoplasmic part (.beta.) or at the NS2/NS3 cleavage site (y). Following transfection of Huh7.5 cells with RNA transcripts, infectious viruses were produced in the ED43/JFH1-.beta. and -y cultures only. Compared to the 2a control virus, production of infectious viruses...... was significantly delayed. However, in subsequent passages efficient spread of infection and high HCV RNA titers were obtained. Infectivity titers were approximately 10-fold lower than for the 2a control virus. Sequence analysis of recovered 4a/2a recombinants from 3 serial passages and subsequent reverse genetic...

  3. Global analysis of the transcriptional response of whitefly to tomato yellow leaf curl China virus reveals the relationship of coevolved adaptations.

    Science.gov (United States)

    Luan, Jun-Bo; Li, Jun-Min; Varela, Nélia; Wang, Yong-Liang; Li, Fang-Fang; Bao, Yan-Yuan; Zhang, Chuan-Xi; Liu, Shu-Sheng; Wang, Xiao-Wei

    2011-04-01

    The begomoviruses are the largest and most economically important group of plant viruses transmitted exclusively by the whitefly Bemisia tabaci in a circulative, persistent manner. The circulation of the viruses within the insect vectors involves complex interactions between virus and vector components; however, the molecular mechanisms of these interactions remain largely unknown. Here we investigated the transcriptional response of the invasive B. tabaci Middle East-Asia Minor 1 species to Tomato yellow leaf curl China virus (TYLCCNV) using Illumina sequencing technology. Results showed that 1,606 genes involved in 157 biochemical pathways were differentially expressed in the viruliferous whiteflies. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that TYLCCNV can perturb the cell cycle and primary metabolism in the whitefly, which explains the negative effect of this virus on the longevity and fecundity of B. tabaci. Our data also demonstrated that TYLCCNV can activate whitefly immune responses, such as autophagy and antimicrobial peptide production, which might lead to a gradual decrease of viral particles within the body of the viruliferous whitefly. Furthermore, PCR results showed that TYLCCNV can invade the ovary and fat body tissues of the whitefly, and Lysotracker and Western blot analyses revealed that the invasion of TYLCCNV induced autophagy in both the ovary and fat body tissues. Surprisingly, TYLCCNV also suppressed the whitefly immune responses by downregulating the expression of genes involved in Toll-like signaling and mitogen-activated protein kinase (MAPK) pathways. Taken together, these results reveal the relationship of coevolved adaptations between begomoviruses and whiteflies and will provide a road map for future investigations into the complex interactions between plant viruses and their insect vectors.

  4. Feasibility of Adapting Multisystemic Therapy to Improve Illness Management Behaviors and Reduce Asthma Morbidity in High Risk African American Youth: A Case Series

    Science.gov (United States)

    Naar-King, Sylvie; Ellis, Deborah; Kolmodin, Karen; Cunningham, Phillippe; Secord, Elizabeth

    2009-01-01

    African-American adolescents have the highest rates of asthma morbidity and mortality, yet there are few successful behavioral interventions to improve illness management for this group. Mental health providers have an opportunity to expand their services and impact by targeting adolescents with poor asthma management. We describe the adaptation…

  5. Evolution and Spread of Ebola Virus in Liberia, 2014-2015.

    Science.gov (United States)

    Ladner, Jason T; Wiley, Michael R; Mate, Suzanne; Dudas, Gytis; Prieto, Karla; Lovett, Sean; Nagle, Elyse R; Beitzel, Brett; Gilbert, Merle L; Fakoli, Lawrence; Diclaro, Joseph W; Schoepp, Randal J; Fair, Joseph; Kuhn, Jens H; Hensley, Lisa E; Park, Daniel J; Sabeti, Pardis C; Rambaut, Andrew; Sanchez-Lockhart, Mariano; Bolay, Fatorma K; Kugelman, Jeffrey R; Palacios, Gustavo

    2015-12-01

    The 2013-present Western African Ebola virus disease (EVD) outbreak is the largest ever recorded with >28,000 reported cases. Ebola virus (EBOV) genome sequencing has played an important role throughout this outbreak; however, relatively few sequences have been determined from patients in Liberia, the second worst-affected country. Here, we report 140 EBOV genome sequences from the second wave of the Liberian outbreak and analyze them in combination with 782 previously published sequences from throughout the Western African outbreak. While multiple early introductions of EBOV to Liberia are evident, the majority of Liberian EVD cases are consistent with a single introduction, followed by spread and diversification within the country. Movement of the virus within Liberia was widespread, and reintroductions from Liberia served as an important source for the continuation of the already ongoing EVD outbreak in Guinea. Overall, little evidence was found for incremental adaptation of EBOV to the human host.

  6. Examining the Specific Effects of Context on Adaptive Behavior and Achievement in a Rural African Community: Six Case Studies from Rural Areas of Southern Province, Zambia

    Science.gov (United States)

    Tan, Mei; Reich, Jodi; Hart, Lesley; Thuma, Philip E.; Grigorenko, Elena L.

    2014-01-01

    Generally accepted as universal, the construct of adaptive behavior differs in its manifestations across different cultures and settings. The Vineland-II (Sparrow et al. in "Vineland Adaptive Behavior Scales, Second edn." AGS Publishing, Circle Pines, MN, 2005) was translated into Chitonga and adapted to the setting of rural Southern…

  7. Vaccination of mice with a modified Vaccinia Ankara (MVA) virus expressing the African horse sickness virus (AHSV) capsid protein VP2 induces virus neutralising antibodies that confer protection against AHSV upon passive immunisation.

    Science.gov (United States)

    Calvo-Pinilla, Eva; de la Poza, Francisco; Gubbins, Simon; Mertens, Peter Paul Clement; Ortego, Javier; Castillo-Olivares, Javier

    2014-02-13

    In previous studies we showed that a recombinant Modified Vaccinia Ankara (MVA) virus expressing the protein VP2 of AHSV serotype 4 (MVA-VP2) induced virus neutralising antibodies in horses and protected interferon alpha receptor gene knock-out mice (IFNAR-/-) against challenge. We continued these studies and determined, in the IFNAR-/- mouse model, whether the antibody responses induced by MVA-VP2 vaccination play a key role in protection against AHSV. Thus, groups of mice were vaccinated with wild type MVA (MVA-wt) or MVA-VP2 and the antisera from these mice were used in a passive immunisation experiment. Donor antisera from (a) MVA-wt; (b) MVA-VP2 vaccinated; or (c) MVA-VP2 vaccinated and AHSV infected mice, were transferred to AHSV non-immune recipient mice. The recipients were challenged with virulent AHSV together with MVA-VP2 vaccinated and MVA-wt vaccinated control animals and the levels of protection against AHSV-4 were compared between all these groups. The results showed that following AHSV challenge, mice that were passively immunised with MVA-VP2 vaccinated antisera were highly protected against AHSV disease and had lower levels of viraemia than recipients of MVA-wt antisera. Our study indicates that MVA-VP2 vaccination induces a highly protective humoral immune response against AHSV.

  8. Adjuvant effects of invariant NKT cell ligand potentiates the innate and adaptive immunity to an inactivated H1N1 swine influenza virus vaccine in pigs.

    Science.gov (United States)

    Dwivedi, Varun; Manickam, Cordelia; Dhakal, Santosh; Binjawadagi, Basavaraj; Ouyang, Kang; Hiremath, Jagadish; Khatri, Mahesh; Hague, Jacquelyn Gervay; Lee, Chang Won; Renukaradhya, Gourapura J

    2016-04-15

    Pigs are considered as the source of some of the emerging human flu viruses. Inactivated swine influenza virus (SwIV) vaccine has been in use in the US swine herds, but it failed to control the flu outbreaks. The main reason has been attributed to lack of induction of strong local mucosal immunity in the respiratory tract. Invariant natural killer T (iNKT) cell is a unique T cell subset, and activation of iNKT cell using its ligand α-Galactosylceramide (α-GalCer) has been shown to potentiate the cross-protective immunity to inactivated influenza virus vaccine candidates in mice. Recently, we discovered iNKT cell in pig and demonstrated its activation using α-GalCer. In this study, we evaluated the efficacy of an inactivated H1N1 SwIV coadministered with α-GalCer intranasally against a homologous viral challenge. Our results demonstrated the potent adjuvant effects of α-GalCer in potentiating both innate and adaptive immune responses to SwIV Ags in the lungs of pigs, which resulted in reduction in the lung viral load by 3 logs compared to without adjuvant. Immunologically, in the lungs of pigs vaccinated with α-GalCer an increased virus specific IgA response, IFN-α secretion and NK cell-cytotoxicity was observed. In addition, iNKT cell-stimulation enhanced the secretion of Th1 cytokines (IFN-γ and IL-12) and reduced the production of immunosuppressive cytokines (IL-10 and TGF-β) in the lungs of pigs⋅ In conclusion, we demonstrated for the first time iNKT cell adjuvant effects in pigs to SwIV Ags through augmenting the innate and adaptive immune responses in the respiratory tract.

  9. West Nile Virus: Using Adapted Primary Literature in Mathematical Biology to Teach Scientific and Mathematical Reasoning in High School

    Science.gov (United States)

    Norris, Stephen P.; Macnab, John S.; Wonham, Marjorie; de Vries, Gerda

    2009-01-01

    This paper promotes the use of adapted primary literature as a curriculum and instruction innovation for use in high school. Adapted primary literature is useful for promoting an understanding of scientific and mathematical reasoning and argument and for introducing modern science into the schools. We describe a prototype adapted from a published…

  10. The presence of alpha interferon at the time of infection alters the innate and adaptive immune responses to porcine reproductive and respiratory syndrome virus.

    Science.gov (United States)

    Brockmeier, Susan L; Loving, Crystal L; Nelson, Eric A; Miller, Laura C; Nicholson, Tracy L; Register, Karen B; Grubman, Marvin J; Brough, Douglas E; Kehrli, Marcus E

    2012-04-01

    Porcine reproductive and respiratory syndrome (PRRS) is one of the most devastating and costly diseases to the swine industry worldwide. Overall, the adaptive immune response to PRRS virus (PRRSV) is weak, which results in delayed elimination of virus from the host and inferior vaccine protection. PRRSV has been shown to induce a meager alpha interferon (IFN-α) response, and we hypothesized that elevated IFN-α levels early in infection would shorten the induction time and increase elements of the adaptive immune response. To test this, we measured both antibody and cell-mediated immunity in pigs after the administration of a nonreplicating human adenovirus type 5 vector expressing porcine IFN-α (Ad5-pIFN-α) at the time of PRRSV infection and compared the results to those for pigs infected with PRRSV alone. Viremia was delayed, and there was a decrease in viral load in the sera of pigs administered the Ad5-pIFN-α. Although seroconversion was slightly delayed in pigs receiving Ad5-pIFN-α, probably due to the early reduction in viral replication, little difference in the overall or neutralizing antibody response was seen. However, there was an increase in the number of virus-specific IFN-γ-secreting cells detected in the pigs receiving Ad5-pIFN-α, as well as an altered cytokine profile in the lung at 14 days postinfection, indicating that the presence of IFN-α at the time of infection can alter innate and adaptive immune responses to PRRSV.

  11. Dengue virus genomic variation associated with mosquito adaptation defines the pattern of viral non-coding RNAs and fitness in human cells

    Science.gov (United States)

    Aguirre, Sebastian; Pallarés, Horacio M.; Blair, Carol D.; Fabri, Cintia; Morales, Maria A.; Fernandez-Sesma, Ana; Gamarnik, Andrea V.

    2017-01-01

    The Flavivirus genus includes a large number of medically relevant pathogens that cycle between humans and arthropods. This host alternation imposes a selective pressure on the viral population. Here, we found that dengue virus, the most important viral human pathogen transmitted by insects, evolved a mechanism to differentially regulate the production of viral non-coding RNAs in mosquitos and humans, with a significant impact on viral fitness in each host. Flavivirus infections accumulate non-coding RNAs derived from the viral 3’UTRs (known as sfRNAs), relevant in viral pathogenesis and immune evasion. We found that dengue virus host adaptation leads to the accumulation of different species of sfRNAs in vertebrate and invertebrate cells. This process does not depend on differences in the host machinery; but it was found to be dependent on the selection of specific mutations in the viral 3’UTR. Dissecting the viral population and studying phenotypes of cloned variants, the molecular determinants for the switch in the sfRNA pattern during host change were mapped to a single RNA structure. Point mutations selected in mosquito cells were sufficient to change the pattern of sfRNAs, induce higher type I interferon responses and reduce viral fitness in human cells, explaining the rapid clearance of certain viral variants after host change. In addition, using epidemic and pre-epidemic Zika viruses, similar patterns of sfRNAs were observed in mosquito and human infected cells, but they were different from those observed during dengue virus infections, indicating that distinct selective pressures act on the 3’UTR of these closely related viruses. In summary, we present a novel mechanism by which dengue virus evolved an RNA structure that is under strong selective pressure in the two hosts, as regulator of non-coding RNA accumulation and viral fitness. This work provides new ideas about the impact of host adaptation on the variability and evolution of flavivirus 3

  12. Antibodies Against Foot-and-mouth Disease (FMD) Virus in African Buffalos (Syncerus caffer) in Selected National Parks in Uganda (2001–2003)

    DEFF Research Database (Denmark)

    Ayebazibwe, C.; Mwiine, F. N.; Balinda, S. N.

    2010-01-01

    the presence of antibodies against FMDV serotypes in wildlife in Uganda, serological studies were performed on buffalo serum samples collected between 2001 and 2003. Thirty-eight samples from African buffalos collected from Lake Mburo, Kidepo Valley, Murchison Falls and Queen Elizabeth National Parks were...... immunosorbent assay (ELISAs). High titres of antibodies (≥1 : 160) against FMDV serotypes SAT 1, SAT 2 and SAT 3 were identified. This study suggests that African buffalos in the different national parks in Uganda may play an important role in the epidemiology of SAT serotypes of FMDV....

  13. Dynamics of adaptive and innate immunity in patients treated during primary human immunodeficiency virus infection: results from Maraviroc in HIV Acute Infection (MAIN) randomized clinical trial.

    Science.gov (United States)

    Ripa, M; Pogliaghi, M; Chiappetta, S; Galli, L; Pensieroso, S; Cavarelli, M; Scarlatti, G; De Biasi, S; Cossarizza, A; De Battista, D; Malnati, M; Lazzarin, A; Nozza, S; Tambussi, G

    2015-09-01

    We evaluated the dynamics of innate and adaptive immunity in patients treated with combined antiretroviral therapy (cART) during primary human immunodeficiency virus infection (PHI), enrolled in a prospective randomized trial (MAIN, EUDRACT 2008-007004-29). After 48 weeks of cART, we documented a reduction in activated B cells and CD8(+) T cells. Natural killer cell and dendritic cell frequencies were measured and a decrease in CD16(+) CD56(dim) with a reciprocal rise in CD56(high) natural killer cells and an increase in myeloid and plasmacytoid dendritic cells were recorded. In conclusion, 48 weeks of cART during PHI showed significant benefits for both innate and adaptive immunity.

  14. Development of a suspension microarray for the genotyping of African swine fever virus targeting the SNPs in the C-terminal end of the p72 gene region of the genome.

    Science.gov (United States)

    Leblanc, N; Cortey, M; Fernandez Pinero, J; Gallardo, C; Masembe, C; Okurut, A R; Heath, L; van Heerden, J; Sánchez-Vizcaino, J M; Ståhl, K; Belák, S

    2013-08-01

    African swine fever virus (ASFV) causes one of the most dreaded transboundary animal diseases (TADs) in Suidae. African swine fever (ASF) often causes high rates of morbidity and mortality, which can reach 100% in domestic swine. To date, serological diagnosis has the drawback of not being able to differentiate variants of this virus. Previous studies have identified the 22 genotypes based on sequence variation in the C-terminal region of the p72 gene, which has become the standard for categorizing ASFVs. This article describes a genotyping assay developed using a segment of PCR-amplified genomic DNA of approximately 450 bp, which encompasses the C-terminal end of the p72 gene. Complementary paired DNA probes of 15 or 17 bp in length, which are identical except for a single nucleotide polymorphism (SNP) in the central position, were designed to either individually or in combination differentiate between the 22 genotypes. The assay was developed using xMAP technology; probes were covalently linked to microspheres, hybridized to PCR product, labelled with a reporter and read in the Luminex 200 analyzer. Characterization of the sample was performed by comparing fluorescence of the paired SNP probes, that is, the probe with higher fluorescence in a complementary pair identified the SNP that a particular sample possessed. In the final assay, a total of 52 probes were employed, 24 SNP pairs and 4 for general detection. One or more samples from each of the 22 genotypes were tested. The assay was able to detect and distinguish all 22 genotypes. This novel assay provides a powerful novel tool for the simultaneous rapid diagnosis and genotypic differentiation of ASF.

  15. Advances in Study on African Swine Fever Virus Etiology and Monoclonal Antibody Preparation Technology%非洲猪瘟病原学及单克隆抗体制备技术研究进展

    Institute of Scientific and Technical Information of China (English)

    陈轶; 王君玮; 曹金山; 邹艳丽; 吴晓东

    2012-01-01

    African swine fever (ASF) is a highly contagious and fatal hemorrhagic viral disease of domestic pigs caused by African swine fever virus (ASFV). Since the mid-twentieth century, ASF has been disseminated in dozens of countries in Africa, Europe and America, and in recent years it spread to Georgia, Armenia, Azerbaijan and Russia. Once ASF invaded to China, it would cause great loss to the pig industry. The studies about the etiology and monoclonal antibodies of ASF make sense about the rapid diagnostic techniques of ASF virus and the development of vaccines. Advances in study on the etiology and monoclonal antibodies of ASF were summarized in this paper.%非洲猪瘟是由非洲猪瘟病毒引起猪的高度接触性、传染性、出血性以及高死亡率的传染病。20世纪中期以来,已在非洲、欧洲和美洲等数十个国家流行,并在近几年内蔓延至欧亚两洲接壤处的格鲁吉亚、亚美尼亚、阿塞拜疆以及俄罗斯境内,其一旦侵入我国,将会给我国养猪业带来极大的危害。非洲猪瘟病原学研究以及制备相应的单克隆抗体对非洲猪瘟病毒快速诊断技术研究和疫苗研制有着重大的现实意义。主要从病原学和单克隆抗体制备方面对非洲猪瘟的研究进展进行了综述。

  16. Clinical profile and containment of the Ebola virus disease outbreak in two large West African cities, Nigeria, July–September 2014

    Directory of Open Access Journals (Sweden)

    Chima Ohuabunwo

    2016-12-01

    Conclusion: The EVD outbreak in Nigeria was characterized by the severe febrile gastroenteritis syndrome typical of the West African outbreak, better outcomes, rapid containment, and no infection among EVD care-providers. Early case detection, an effective incident management system, and prompt case management with on-site mobilization and training of local professionals were key to the outcome.

  17. Molecular mechanisms of serum resistance of human influenza H3N2 virus and their involvement in virus adaptation in a new host.

    Science.gov (United States)

    Matrosovich, M; Gao, P; Kawaoka, Y

    1998-08-01

    H3N2 human influenza viruses that are resistant to horse, pig, or rabbit serum possess unique amino acid mutations in their hemagglutinin (HA) protein. To determine the molecular mechanisms of this resistance, we characterized the receptor-binding properties of these mutants by measuring their affinity for total serum protein inhibitors and for soluble receptor analogs. Pig serum-resistant variants displayed a markedly decreased affinity for total pig serum sialylglycoproteins (which contain predominantly 2-6 linkage between sialic acid and galactose residues) and for the sialyloligosaccharide 6'-sialyl(N-acetyllactosamine). These properties correlated with the substitution 186S-->I in HA1. The major inhibitory activity in rabbit serum was found to be a beta inhibitor with characteristics of mannose-binding lectins. Rabbit serum-resistant variants exhibited decreased sensitivity to this inhibitor due to the loss of a glycosylation sequon at positions 246 to 248 of the HA. In addition to a somewhat reduced affinity for 6'-sialyl(N-acetyllactosamine)-containing receptors, horse serum-resistant variants lost the ability to bind the viral neuraminidase-resistant 4-O-acetylated sialic acid moieties of equine alpha2-macroglobulin because of the mutation 145N-->K/D in their HA1. These results indicate that influenza viruses become resistant to serum inhibitors because their affinity for these inhibitors is reduced. To determine whether natural inhibitors play a role in viral evolution during interspecies transmission, we compared the receptor-binding properties of H3N8 avian and equine viruses, including two strains isolated during the 1989 to 1990 equine influenza outbreak, which was caused by an avian virus in China. Avian strains bound 4-O-acetylated sialic acid residues of equine alpha2-macroglobulin, whereas equine strains did not. The earliest avian-like isolate from a horse influenza outbreak bound to this sialic acid with an affinity similar to that of avian

  18. Clinical significance of variations in levels of Epstein-Barr Virus (EBV) antigen and adaptive immune response during chronic active EBV infection in children.

    Science.gov (United States)

    Xing, Yan; Song, Hong Mei; Wei, Min; Liu, Yu; Zhang, Yu Hua; Gao, Li

    2013-01-01

    Pediatric patients were recruited to analyze differences in Epstein-Barr virus (EBV) copy numbers and adaptive immune reactions in children with chronic active vs acute EBV infection (CAEBVI vs AEBVI), as well as to examine the relationship between these parameters and the pathogenesis of CAEBVI. Fluorescent qPCR was used to assess EBV-DNA levels, while ELISA, antibody affinity, flow cytometry, and heterophil agglutination (HA) assays were used to evaluate patient EBV-adaptive humoral and cellular immunity. Lastly, ELISPOT was employed to assess interferon (IFN)-γ secretory functions of EBV-specific cytotoxic T-lymphocytes (CTL) as a marker of subject EBV-specific adaptive cellular immunity. The results indicated that, compared with AEBVI patients or normal children, there was a dramatic elevation in viral copy levels, viral capsid antigen (VCA)-IgA, early antigen (EA)-IgA, and EA-IgG, but a lack of EBV nuclear antigen (EBNA)-IgG and a negative HA in CAEBVI patients (p EBV-specific CTL function compared with normal children (p EBV antigen availability and in both the adaptive humoral and cellular immune responses in patients with CAEBVI, and that these outcomes may be associated with the chronic active re-infection process itself associated with CAEBVI.

  19. How student teachers understand African philosophy

    Directory of Open Access Journals (Sweden)

    Matsephe M. Letseka

    2012-10-01

    Full Text Available The question ‘What constitutes African philosophy?’ was first raised with the publication of Placide Tempels’s seminal work Bantu philosophy in 1959. Tempels’s book inevitably elicited considerable critical response from African philosophers, which culminated in a wide range of publications such as Wiredu’s (1980 Philosophy and an African culture, Hountondji’s (1983 African philosophy: Myth and reality, Oruka’s (1990 Sage philosophy: Indigenous thinkers and modern debate on African philosophy, Shutte’s (1993 Philosophy for Africa, Masolo’s (1994 African philosophy in search of identity and Gyekye’s (1995 An essay of African philosophical thought: The Akan conceptual scheme. It has been over 60 years since the publication of Temples’s book and there continues to be serious debate about African philosophy. This article sought to contribute to the debate on the various conceptions of African philosophy, but with a focus on the challenges of teaching African philosophy to Philosophy of Education students at an open distance learning institution in South Africa. This article discussed the tendency amongst undergraduate Philosophy of Education students to conflate and reduce African philosophy to African cultures and traditions, and to the notion of ubuntu, and sought to understand the reasons for students’ inclination to treat African philosophy in this way. It examined students’ background knowledge of African philosophy, their critical thinking skills and whether their official study materials are selected and packaged in a manner that, in fact, adds to the challenges they face. Finally, the article explored the ways in which Philosophy of Education lecturers can adapt their pedagogy to provide students with a better understanding of African philosophy.

  20. Deliberate attenuation of chikungunya virus by adaptation to heparan sulfate-dependent infectivity: a model for rational arboviral vaccine design.

    Science.gov (United States)

    Gardner, Christina L; Hritz, Jozef; Sun, Chengqun; Vanlandingham, Dana L; Song, Timothy Y; Ghedin, Elodie; Higgs, Stephen; Klimstra, William B; Ryman, Kate D

    2014-02-01

    Mosquito-borne chikungunya virus (CHIKV) is a positive-sense, single-stranded RNA virus from the genus Alphavirus, family Togaviridae, which causes fever, rash and severe persistent polyarthralgia in humans. Since there are currently no FDA licensed vaccines or antiviral therapies for CHIKV, the development of vaccine candidates is of critical importance. Historically, live-attenuated vaccines (LAVs) for protection against arthropod-borne viruses have been created by blind cell culture passage leading to attenuation of disease, while maintaining immunogenicity. Attenuation may occur via multiple mechanisms. However, all examined arbovirus LAVs have in common the acquisition of positively charged amino acid substitutions in cell-surface attachment proteins that render virus infection partially dependent upon heparan sulfate (HS), a ubiquitously expressed sulfated polysaccharide, and appear to attenuate by retarding dissemination of virus particles in vivo. We previously reported that, like other wild-type Old World alphaviruses, CHIKV strain, La Réunion, (CHIKV-LR), does not depend upon HS for infectivity. To deliberately identify CHIKV attachment protein mutations that could be combined with other attenuating processes in a LAV candidate, we passaged CHIKV-LR on evolutionarily divergent cell-types. A panel of single amino acid substitutions was identified in the E2 glycoprotein of passaged virus populations that were predicted to increase electrostatic potential. Each of these substitutions was made in the CHIKV-LR cDNA clone and comparisons of the mutant viruses revealed surface exposure of the mutated residue on the spike and sensitivity to competition with the HS analog, heparin, to be primary correlates of attenuation in vivo. Furthermore, we have identified a mutation at E2 position 79 as a promising candidate for inclusion in a CHIKV LAV.

  1. Deliberate attenuation of chikungunya virus by adaptation to heparan sulfate-dependent infectivity: a model for rational arboviral vaccine design.

    Directory of Open Access Journals (Sweden)

    Christina L Gardner

    2014-02-01

    Full Text Available Mosquito-borne chikungunya virus (CHIKV is a positive-sense, single-stranded RNA virus from the genus Alphavirus, family Togaviridae, which causes fever, rash and severe persistent polyarthralgia in humans. Since there are currently no FDA licensed vaccines or antiviral therapies for CHIKV, the development of vaccine candidates is of critical importance. Historically, live-attenuated vaccines (LAVs for protection against arthropod-borne viruses have been created by blind cell culture passage leading to attenuation of disease, while maintaining immunogenicity. Attenuation may occur via multiple mechanisms. However, all examined arbovirus LAVs have in common the acquisition of positively charged amino acid substitutions in cell-surface attachment proteins that render virus infection partially dependent upon heparan sulfate (HS, a ubiquitously expressed sulfated polysaccharide, and appear to attenuate by retarding dissemination of virus particles in vivo. We previously reported that, like other wild-type Old World alphaviruses, CHIKV strain, La Réunion, (CHIKV-LR, does not depend upon HS for infectivity. To deliberately identify CHIKV attachment protein mutations that could be combined with other attenuating processes in a LAV candidate, we passaged CHIKV-LR on evolutionarily divergent cell-types. A panel of single amino acid substitutions was identified in the E2 glycoprotein of passaged virus populations that were predicted to increase electrostatic potential. Each of these substitutions was made in the CHIKV-LR cDNA clone and comparisons of the mutant viruses revealed surface exposure of the mutated residue on the spike and sensitivity to competition with the HS analog, heparin, to be primary correlates of attenuation in vivo. Furthermore, we have identified a mutation at E2 position 79 as a promising candidate for inclusion in a CHIKV LAV.

  2. Successful cross-protective efficacy induced by heat-adapted live attenuated nephropathogenic infectious bronchitis virus derived from a natural recombinant strain.

    Science.gov (United States)

    Lim, Tae-Hyun; Youn, Ha-Na; Yuk, Seong-Su; Kwon, Jung-Hoon; Hong, Woo-Tack; Gwon, Gyeong-Bin; Lee, Jung-Ah; Lee, Joong-Bok; Lee, Sang-Won; Song, Chang-Seon

    2015-12-16

    A natural recombinant nephropathogenic K40/09 strain of infectious bronchitis virus (IBV) was heat-adapted for possible future use as live attenuated vaccine. The K40/09 strain was selected during successive serial passages in specific-pathogen free (SPF) embryonated eggs at sub-optimal higher temperature (56°C). Unlike the parental strain, the attenuated strain, designated K40/09 HP50, was found to be safe in 1-day-old SPF chicks, which showed neither mortality nor signs of morbidity, and rarely induced ciliostasis or histological changes in the trachea and kidney after intraocular and fine-spray administration. K40/09 HP50 provided almost complete protection against two distinct subgroups of a nephropathogenic strain (KM91-like and QX-like subgroup) and elicited the production of high titers of neutralizing antibody (neutralization index of 3.6). We conclude that the K40/09 HP50 vaccine virus is rapidly attenuated by heat adaptation and exhibits the desired level of attenuation, immunogenicity, and protective efficacy required for a live attenuated vaccine. These results indicate that the K40/09 vaccine could be helpful for the reduction of economic losses caused by recently emergent nephropathogenic IBV infection in many countries.

  3. A genomic portrait of haplotype diversity and signatures of selection in indigenous southern African populations.

    Directory of Open Access Journals (Sweden)

    Emile R Chimusa

    2015-03-01

    Full Text Available We report a study of genome-wide, dense SNP (∼ 900K and copy number polymorphism data of indigenous southern Africans. We demonstrate the genetic contribution to southern and eastern African populations, which involved admixture between indigenous San, Niger-Congo-speaking and populations of Eurasian ancestry. This finding illustrates the need to account for stratification in genome-wide association studies, and that admixture mapping would likely be a successful approach in these populations. We developed a strategy to detect the signature of selection prior to and following putative admixture events. Several genomic regions show an unusual excess of Niger-Kordofanian, and unusual deficiency of both San and Eurasian ancestry, which were considered the footprints of selection after population admixture. Several SNPs with strong allele frequency differences were observed predominantly between the admixed indigenous southern African populations, and their ancestral Eurasian populations. Interestingly, many candidate genes, which were identified within the genomic regions showing signals for selection, were associated with southern African-specific high-risk, mostly communicable diseases, such as malaria, influenza, tuberculosis, and human immunodeficiency virus/AIDs. This observation suggests a potentially important role that these genes might have played in adapting to the environment. Additionally, our analyses of haplotype structure, linkage disequilibrium, recombination, copy number variation and genome-wide admixture highlight, and support the unique position of San relative to both African and non-African populations. This study contributes to a better understanding of population ancestry and selection in south-eastern African populations; and the data and results obtained will support research into the genetic contributions to infectious as well as non-communicable diseases in the region.

  4. TLR-independent induction of dendritic cell maturation and adaptive immunity by negative-strand RNA viruses.

    Science.gov (United States)

    López, Carolina B; Moltedo, Bruno; Alexopoulou, Lena; Bonifaz, Laura; Flavell, Richard A; Moran, Thomas M

    2004-12-01

    TLR signaling leads to dendritic cell (DC) maturation and immunity to diverse pathogens. The stimulation of TLRs by conserved viral structures is the only described mechanism leading to DC maturation after a virus infection. In this report, we demonstrate that mouse myeloid DCs mature normally after in vivo and in vitro infection with Sendai virus (SeV) in the absence of TLR3, 7, 8, or 9 signaling. DC maturation by SeV requires virus replication not necessary for TLR-mediated triggering. Moreover, DCs deficient in TLR signaling efficiently prime for Th1 immunity after infection with influenza or SeV, generating IFN-gamma-producing T cells, CTLs and antiviral Abs. We have previously demonstrated that SeV induces DC maturation independently of the presence of type I IFN, which has been reported to mature DCs in a TLR-independent manner. The data presented here provide evidence for the existence of a novel intracellular pathway independent of TLR-mediated signaling responsible for live virus triggering of DC maturation and demonstrate its critical role in the onset of antiviral immunity. The revelation of this pathway should stimulate invigorating research into the mechanism for virus-induced DC maturation and immunity.

  5. Metagenomic study of the viruses of African straw-coloured fruit bats: detection of a chiropteran poxvirus and isolation of a novel adenovirus.

    Science.gov (United States)

    Baker, Kate S; Leggett, Richard M; Bexfield, Nicholas H; Alston, Mark; Daly, Gordon; Todd, Shawn; Tachedjian, Mary; Holmes, Clare E G; Crameri, Sandra; Wang, Lin-Fa; Heeney, Jonathan L; Suu-Ire, Richard; Kellam, Paul; Cunningham, Andrew A; Wood, James L N; Caccamo, Mario; Murcia, Pablo R

    2013-07-05

    Viral emergence as a result of zoonotic transmission constitutes a continuous public health threat. Emerging viruses such as SARS coronavirus, hantaviruses and henipaviruses have wildlife reservoirs. Characterising the viruses of candidate reservoir species in geographical hot spots for viral emergence is a sensible approach to develop tools to predict, prevent, or contain emergence events. Here, we explore the viruses of Eidolon helvum, an Old World fruit bat species widely distributed in Africa that lives in close proximity to humans. We identified a great abundance and diversity of novel herpes and papillomaviruses, described the isolation of a novel adenovirus, and detected, for the first time, sequences of a chiropteran poxvirus closely related with Molluscum contagiosum. In sum, E. helvum display a wide variety of mammalian viruses, some of them genetically similar to known human pathogens, highlighting the possibility of zoonotic transmission.

  6. Quantification of Human T-lymphotropic virus type I (HTLV-I) provirus load in a rural West African population: no enhancement of human immunodeficiency virus type 2 pathogenesis, but HTLV-I provirus load relates to mortality

    DEFF Research Database (Denmark)

    Ariyoshi, K; Berry, N; Cham, F;

    2003-01-01

    Human T-lymphotropic virus type I (HTLV-I) provirus load was examined in a cohort of a population in Guinea-Bissau among whom human immunodeficiency virus (HIV) type 2 is endemic. Geometric mean of HIV-2 RNA load among HTLV-I-coinfected subjects was significantly lower than that in subjects infec...

  7. Molecular analysis and associated pathology of beak and feather disease virus isolated in Italy from young Congo African grey parrots (Psittacus erithacus) with an "atypical peracute form" of the disease.

    Science.gov (United States)

    Robino, Patrizia; Grego, Elena; Rossi, Giacomo; Bert, Elena; Tramuta, Clara; Stella, Maria Cristina; Bertoni, Pierfrancesco; Nebbia, Patrizia

    2014-01-01

    This study is the first report on the genetic and pathogenic characterization of beak and feather disease virus (BFDV) occurring in Italy. Twenty BFDV strains isolated in Italy from juvenile Congo African grey parrots (Psittacus erithacus) were investigated. Seventeen strains showed an "atypical peracute form" (aPF) of the disease, and three a chronic form (CF). The birds with aPF had been weaned, were independent as far as food and protection were concerned and apparently were without lesions. The gene coding for the putative coat protein was amplified in all isolates while the BFDV genome was sequenced completely in 10 samples, eight of them belonging to aPF affected birds and two from CF of the disease. All full genomes clustered into the J strain of BFDV, where two new subtypes were identified. Recombination analyses showed evidence of genetic exchanges in two BFDV genomes. In addition, a correlation between viral isolate and origin of the breeding material was shown, while an association between the genetic features of the virus and the clinical form was not observed. Histologically, apoptosis was detected frequently in aPF samples and sporadically in CF samples. Interestingly, BFDV antigens were detected in the nuclei and cytoplasm of such apoptotic cells. The data presented here support the hypothesis that, in the absence of a defined BFDV genetic variant accountable for a specific clinical form of psittacine beak and feather disease, differences in the apoptotic rate between aPF and CF are strictly host related.

  8. 非洲猪瘟病毒实时荧光定量PCR检测方法的建立及应用%Construction and Application of Real-time Quantitative PCR for Detection of African Swine Fever Virus

    Institute of Scientific and Technical Information of China (English)

    李洪利; 曹金山; 王君玮; 张维

    2012-01-01

    本研究为了建立一套检测非洲猪瘟病毒(African swine fever virus,ASFV)的实时荧光定量PCR检测方法,根据GenBank公布的23株编码ASFV结构蛋白p72的基因序列,设计引物和探针,优化退火温度、Mg2+浓度和引物、探针浓度,生成标准曲线,进行重复性、敏感性、特异性试验,并检测样品.结果显示,优化的退火温度为60℃,Mg2+终浓度为4 mmol/L,引物、探针终浓度分别为0.8、0.3μmol/L.重复性试验变异系数均小于1.3%,敏感性试验最低能够检测到10拷贝/μL的质粒,以其他5种猪病病毒和ASFV质粒为模板进行特异性试验,只有ASFV质粒出现扩增曲线.结果表明,建立的实时荧光定量PCR方法是快速、灵敏、特异的检测ASFV的方法.%In order to construct real-time quantitative PCR assay for detection of African swine fever virus, this study was based on 23 isolates of gene sequence which encodes ASFV structural protein p72 in GenBank, then designing primers and probe. The reaction conditions were optimized by using different annealing temperature, different Mg2+ concentrations, different primers and probe concentrations. The real-time PCR system could automatically generate standard curve, testing repeatability, sensitivity and specificity. Wild boar samples were detected by this assay. The results showed optimal annealing temperature was 60 ℃. optimal Mg2+ concentration was 4 mraol/'L, optimal primers and probe concentration were 0. 8 and 0. 3 μmol/L. The coefficients of variation of repeatability test were less than 1. 3% , sensitivity tests could detect 10 copies/μL plas-mids, the specificity was tested by detecting five others swine viruses and ASFV plasmid, only detection of ASFV plasmid appears amplification curve. In conclusion, constructed real-time quantitative PCR assay was rapid .sensitive and specific assay for detection of ASFV.

  9. Robust hepatitis C genotype 3a cell culture releasing adapted intergenotypic 3a/2a (S52/JFH1) viruses

    DEFF Research Database (Denmark)

    Gottwein, J.M.; Scheel, Troels Kasper Høyer; Hoegh, A.M.

    2007-01-01

    BACKGROUND & AIMS: Recently, full viral life cycle hepatitis C virus (HCV) cell culture systems were developed for strain JFH1 (genotype 2a) and an intragenotypic 2a/2a genome (J6/JFH). We aimed at exploiting the unique JFH1 replication characteristics to develop culture systems for genotype 3a......, which has a high prevalence worldwide. METHODS: Huh7.5 cells were transfected with RNA transcripts of an intergenotypic 3a/JFH1 recombinant with core, E1, E2, p7, and NS2 of the 3a reference strain S52, and released viruses were passaged. Cultures were examined for HCV core and/or NS5A expression...... (immunostaining), HCV RNA titers (real-time PCR), and infectivity titers (50% tissue culture infectious dose). The role of mutations identified by sequencing of recovered S52/JFH1 viruses was analyzed by reverse genetics studies. RESULTS: S52/JFH1 and J6/JFH viruses passaged in Huh7.5 cells showed comparable...

  10. Detection of African swine fever, classical swine fever, and foot-and-mouth disease viruses in swine oral fluids by multiplex reverse transcription real-time polymerase chain reaction.

    Science.gov (United States)

    Grau, Frederic R; Schroeder, Megan E; Mulhern, Erin L; McIntosh, Michael T; Bounpheng, Mangkey A

    2015-03-01

    African swine fever (ASF), classical swine fever (CSF), and foot-and-mouth disease (FMD) are highly contagious animal diseases of significant economic importance. Pigs infected with ASF and CSF viruses (ASFV and CSFV) develop clinical signs that may be indistinguishable from other diseases. Likewise, various causes of vesicular disease can mimic clinical signs caused by the FMD virus (FMDV). Early detection is critical to limiting the impact and spread of these disease outbreaks, and the ability to perform herd-level surveillance for all 3 diseases rapidly and cost effectively using a single diagnostic sample and test is highly desirable. This study assessed the feasibility of simultaneous ASFV, CSFV, and FMDV detection by multiplex reverse transcription real-time polymerase chain reaction (mRT-qPCR) in swine oral fluids collected through the use of chewing ropes. Animal groups were experimentally infected independently with each virus, observed for clinical signs, and oral fluids collected and tested throughout the course of infection. All animal groups chewed on the ropes readily before and after onset of clinical signs and before onset of lameness or serious clinical signs. ASFV was detected as early as 3 days postinoculation (dpi), 2-3 days before onset of clinical disease; CSFV was detected at 5 dpi, coincident with onset of clinical disease; and FMDV was detected as early as 1 dpi, 1 day before the onset of clinical disease. Equivalent results were observed in 4 independent studies and demonstrate the feasibility of oral fluids and mRT-qPCR for surveillance of ASF, CSF, and FMD in swine populations.

  11. African America.

    Science.gov (United States)

    Brodie, Carolyn S.; Brown, Gloria

    1994-01-01

    Presents an annotated bibliography of quality materials by and about African Americans in the areas of poetry, music, folklore, women, picture books, history/collective biography, authors, and professional materials. Activities are suggested in each area for Black History Month. (LRW)

  12. 非洲猪瘟病毒p72基因的纳米金探针研究%Study on the nanogold probe to p72 gene of African swine fever virus

    Institute of Scientific and Technical Information of China (English)

    张鑫宇; 孙怀昌; 刘文俊; 夏晓莉; 成大荣

    2011-01-01

    After comparing the p72 genes of 22 African swine fever virus strains, a highly conserved sequence was found, to which two complementary oligonucleotide probes modified with 5'-biotin and 3'-alkylthiol respectively were designed and synthesized. The alkylthiol oligonucleotides were attached to gold nanoparticles by covalent coupling, and the gold nanoparticle probe was prepared. The conservative DNA about 651 bp in p72 gene amplified by PCR was denatured,1which then was hybridized with the probes above. The hybrid products were added into the ELISA plate labeled with streptavidin and captured by affinity. After that, the siliver staining was proceeded to amplify the hybrid signal. The result indicated that the black deposition can be viewed after siliver enhancement,and the DNA amplified can be detected with the lowest the density at 10 fmol · L-1 , which may be used in rapid detection of the African swine fever virus in future.%对22株发表的非洲猪瘟病毒(ASFV)p72基因序列进行比较,找出其中的高保守性区域,各设计、合成1条与保守区域互补的5′生物索标记及3′烷巯基修饰短链寡核苷酸探针,并将烷巯基修饰的探针吸附到纳米金颗粒上,制备纳米金标记探针.PCR扩增出的p72基因中的651 bp保守核酸序列,变性后与上述生物素探针及标记纳米金探针进行杂交,杂交产物加入吸附链霉亲和素的酶标板,利用亲和原理,捕获杂交产物,银染增强法对纳米金标记探针进行信号放大.结果表明:制备的纳米金探针经银染放大后,在酶标板中形成肉眼可见的黑色沉淀,可有效检测扩增出的p72基因,检测核酸浓度达到10 fmol·L-1,可用于ASFV快速诊断.

  13. Innate and Adaptive Immune Response to Pneumonia Virus of Mice in a Resistant and a Susceptible Mouse Strain

    Directory of Open Access Journals (Sweden)

    Ellen R. T. Watkiss

    2013-01-01

    Full Text Available Respiratory syncytial virus (RSV is the leading cause of infant bronchiolitis. The closely related pneumonia virus of mice (PVM causes a similar immune-mediated disease in mice, which allows an analysis of host factors that lead to severe illness. This project was designed to compare the immune responses to lethal and sublethal doses of PVM strain 15 in Balb/c and C57Bl/6 mice. Balb/c mice responded to PVM infection with an earlier and stronger innate response that failed to control viral replication. Production of inflammatory cyto- and chemokines, as well as infiltration of neutrophils and IFN-γ secreting natural killer cells into the lungs, was more predominant in Balb/c mice. In contrast, C57Bl/6 mice were capable of suppressing both viral replication and innate inflammatory responses. After a sublethal infection, PVM-induced IFN-γ production by splenocytes was stronger early during infection and weaker at late time points in C57Bl/6 mice when compared to Balb/c mice. Furthermore, although the IgG levels were similar and the mucosal IgA titres lower, the virus neutralizing antibody titres were higher in C57Bl/6 mice than in Balb/c mice. Overall, the difference in susceptibility of these two strains appeared to be related not to an inherent T helper bias, but to the capacity of the C57Bl/6 mice to control both viral replication and the immune response elicited by PVM.

  14. Virological and serological findings in Rousettus aegyptiacus experimentally inoculated with vero cells-adapted hogan strain of Marburg virus.

    Directory of Open Access Journals (Sweden)

    Janusz T Paweska

    Full Text Available The Egyptian fruit bat, Rousettus aegyptiacus, is currently regarded as a potential reservoir host for Marburg virus (MARV. However, the modes of transmission, the level of viral replication, tissue tropism and viral shedding pattern remains to be described. Captive-bred R. aegyptiacus, including adult males, females and pups were exposed to MARV by different inoculation routes. Blood, tissues, feces and urine from 9 bats inoculated by combination of nasal and oral routes were all negative for the virus and ELISA IgG antibody could not be demonstrated for up to 21 days post inoculation (p.i.. In 21 bats inoculated by a combination of intraperitoneal/subcutaneous route, viremia and the presence of MARV in different tissues was detected on days 2-9 p.i., and IgG antibody on days 9-21 p.i. In 3 bats inoculated subcutaneously, viremia was detected on days 5 and 8 (termination of experiment, with virus isolation from different organs. MARV could not be detected in urine, feces or oral swabs in any of the 3 experimental groups. However, it was detected in tissues which might contribute to horizontal or vertical transmission, e.g. lung, intestines, kidney, bladder, salivary glands, and female reproductive tract. Viremia lasting at least 5 days could also facilitate MARV mechanical transmission by blood sucking arthropods and infections of susceptible vertebrate hosts by direct contact with infected blood. All bats were clinically normal and no gross pathology was identified on post mortem examination. This work confirms the susceptibility of R. aegyptiacus to infection with MARV irrespective of sex and age and contributes to establishing a bat-filovirus experimental model. Further studies are required to uncover the mode of MARV transmission, and to investigate the putative role of R. aegyptiacus as a reservoir host.

  15. RNA interference of influenza A virus replication by microRNA-adapted lentiviral loop short hairpin RNA.

    Science.gov (United States)

    Xu, Fang; Liu, Guanqun; Liu, Qiang; Zhou, Yan

    2015-10-01

    Limitations of the current vaccines and antivirals against influenza A virus (IAV) pandemic underscore the urgent need for developing novel anti-influenza strategies. RNA interference (RNAi) induced by small interfering RNA (siRNA) has become a powerful new means to inhibit viral infection in a gene-specific manner. However, the efficacy of the siRNA delivery platform and the relatively high cost of administration have hindered widespread application of siRNA. In this study, we developed a microRNA (miRNA)-30-based lentivirus delivery system by embedding a synthetic short hairpin RNA (shRNA) stem into the context of endogenous precursor of miRNA-30 (shRNAmir) to express a silencer of the influenza gene. We showed that the miRNA-based lentivirus vector was able to express and process a single nucleoprotein (NP)-targeting shRNAmir, which could potently inhibit IAV replication. We further showed that miRNA-based lentivirus vector carrying tandemly linked NP and polymerase PB1 shRNAmirs could express and process double shRNAmirs. Despite the relatively low levels of NP and PB1 miRNAs produced in the stably transduced cells, the combination of two miRNAs exerted a great degree of inhibition on influenza infection. Given the advantage of combinatorial RNAi in preventing emergence of mutant virus, miRNA-based lentiviral vectors are valuable tools for anitiviral activities. To the best of our knowledge, this is the first study demonstrating that a miRNA-based RNAi strategy can be applied for better control of influenza virus infection.

  16. Characterization of human antiviral adaptive immune responses during hepatotropic virus infection in HLA-transgenic human immune system mice.

    Science.gov (United States)

    Billerbeck, Eva; Horwitz, Joshua A; Labitt, Rachael N; Donovan, Bridget M; Vega, Kevin; Budell, William C; Koo, Gloria C; Rice, Charles M; Ploss, Alexander

    2013-08-15

    Humanized mice have emerged as a promising model to study human immunity in vivo. Although they are susceptible to many pathogens exhibiting an almost exclusive human tropism, human immune responses to infection remain functionally impaired. It has recently been demonstrated that the expression of HLA molecules improves human immunity to lymphotropic virus infections in humanized mice. However, little is known about the extent of functional human immune responses in nonlymphoid tissues, such as in the liver, and the role of HLA expression in this context. Therefore, we analyzed human antiviral immunity in humanized mice during a hepatotropic adenovirus infection. We compared immune responses of conventional humanized NOD SCID IL-2Rγ-deficient (NSG) mice to those of a novel NOD SCID IL-2Rγ-deficient strain transgenic for both HLA-A*0201 and a chimeric HLA-DR*0101 molecule. Using a firefly luciferase-expressing adenovirus and in vivo bioluminescence imaging, we demonstrate a human T cell-dependent partial clearance of adenovirus-infected cells from the liver of HLA-transgenic humanized mice. This correlated with liver infiltration and activation of T cells, as well as the detection of Ag-specific humoral and cellular immune responses. When infected with a hepatitis C virus NS3-expressing adenovirus, HLA-transgenic humanized mice mounted an HLA-A*0201-restricted hepatitis C virus NS3-specific CD8(+) T cell response. In conclusion, our study provides evidence for the generation of partial functional antiviral immune responses against a hepatotropic pathogen in humanized HLA-transgenic mice. The adenovirus reporter system used in our study may serve as simple in vivo method to evaluate future strategies for improving human intrahepatic immune responses in humanized mice.

  17. Cultural aspects of African American eating patterns.

    Science.gov (United States)

    Airhihenbuwa, C O; Kumanyika, S; Agurs, T D; Lowe, A; Saunders, D; Morssink, C B

    1996-09-01

    The high mortality from diet-related diseases among African Americans strongly suggests a need to adopt diets lower in total fat, saturated fat and salt and higher in fiber. However, such changes would be contrary to some traditional African American cultural practices. Focus group interviews were used to explore cultural aspects of eating patterns among low- and middle-income African Americans recruited from an urban community in Pennsylvania. In total, 21 males and 32 females, aged 13-65+ years were recruited using a networking technique. Participants identified eating practices commonly attributed to African Americans and felt that these were largely independent of socioeconomic status. They were uncertain about links between African American eating patterns and African origins but clear about influences of slavery and economic disadvantage. The perception that African American food patterns were characteristically adaptive to external conditions, suggest that, for effective dietary change in African American communities, changes in the food availability will need to precede or take place in parallel with changes recommended to individuals. Cultural attitudes about where and with whom food is eaten emerged as being equivalent in importance to attitudes about specific foods. These findings emphasize the importance of continued efforts to identify ways to increase the relevance of cultural context and meanings in dietary counseling so that health and nutrition interventions are anchored in values as perceived, in this case, by African Americans.

  18. African-American Biography.

    Science.gov (United States)

    Martin, Ron

    1995-01-01

    Suggests sources of information for African American History Month for library media specialists who work with students in grades four through eight. Gale Research's "African-American Reference Library," which includes "African-America Biography,""African-American Chronology," and "African-American Almanac,"…

  19. Dating the origin of hepatitis B virus reveals higher substitution rate and adaptation on the branch leading to F/H genotypes.

    Science.gov (United States)

    Paraskevis, Dimitrios; Angelis, Konstantinos; Magiorkinis, Gkikas; Kostaki, Evangelia; Ho, Simon Y W; Hatzakis, Angelos

    2015-12-01

    The evolution of hepatitis B virus (HBV), particularly its origins and evolutionary timescale, has been the subject of debate. Three major scenarios have been proposed, variously placing the origin of HBV in humans and great apes from some million years to only a few thousand years ago (ka). To compare these scenarios, we analyzed 105 full-length HBV genome sequences from all major genotypes sampled globally. We found a high correlation between the demographic histories of HBV and humans, as well as coincidence in the times of origin of specific subgenotypes with human migrations giving rise to their host indigenous populations. Together with phylogenetic evidence, this suggests that HBV has co-expanded with modern humans. Based on the co-expansion, we conducted a Bayesian dating analysis to estimate a precise evolutionary timescale for HBV. Five calibrations were used at the origins of F/H genotypes, D4, C3 and B6 from respective indigenous populations in the Pacific and Arctic and A5 from Haiti. The estimated time for the origin of HBV was 34.1ka (95% highest posterior density interval 27.6-41.3ka), coinciding with the dispersal of modern non-African humans. Our study, the first to use full-length HBV sequences, places a precise timescale on the HBV epidemic and also shows that the "branching paradox" of the more divergent genotypes F/H from Amerindians is due to an accelerated substitution rate, probably driven by positive selection. This may explain previously observed differences in the natural history of HBV between genotypes F1 and A2, B1, and D.

  20. Molecular adaptation within the coat protein-encoding gene of Tunisian almond isolates of Prunus necrotic ringspot virus

    Indian Academy of Sciences (India)

    Moncef Boulila; Sawssen Ben Tiba; Saoussen Jilani

    2013-04-01

    The sequence alignments of five Tunisian isolates of Prunus necrotic ringspot virus (PNRSV) were searched for evidence of recombination and diversifying selection. Since failing to account for recombination can elevate the false positive error rate in positive selection inference, a genetic algorithm (GARD) was used first and led to the detection of potential recombination events in the coat protein-encoding gene of that virus. The Recco algorithm confirmed these results by identifying, additionally, the potential recombinants. For neutrality testing and evaluation of nucleotide polymorphism in PNRSV CP gene, Tajima’s , and Fu and Li’s and statistical tests were used. About selection inference, eight algorithms (SLAC, FEL, IFEL, REL, FUBAR, MEME, PARRIS, and GA branch) incorporated in HyPhy package were utilized to assess the selection pressure exerted on the expression of PNRSV capsid. Inferred phylogenies pointed out, in addition to the three classical groups (PE-5, PV-32, and PV-96), the delineation of a fourth cluster having the new proposed designation SW6, and a fifth clade comprising four Tunisian PNRSV isolates which underwent recombination and selective pressure and to which the name Tunisian outgroup was allocated.

  1. African Trypanosomiasis

    Science.gov (United States)

    2011-06-01

    Histol. 1977;375:53- 70. 42. Poltera AA, Owor R, Cox JN. Pathological aspects of human African trypanosomiasis (HAT) in Uganda. A post - mortem survey of...nodular lesions , including anthrax or tick bite associated with Rickettsia conorii infection. The chancre is followed by a hemolymphatic stage, dur- ing...electrocardiograph- ic changes and, at times, terminal cardiac insufficiency.41 Pulmonary lesions specifically related to trypanosomiasis are not

  2. AN ALTERNATIVE VIEW OF SOUTH AFRICAN ARTILLERY

    Directory of Open Access Journals (Sweden)

    A.C. Lillie

    2012-02-01

    Full Text Available It has been said that 'Necessity is the mother of invention' and there can be few countries, if any, where this is more true than in South Africa.In the late 1930's, prior to World War II, the South African Artillery was severely restricted due to its lack of mobility. The inventiveness shown in tackling this probelm is surely not a thing of the past and the possiblity of adapting South African artillery to current South african needs in warfare should not be overlooked. The South African Defence Force is not able to purchase armament in a free and open market place and the costs of developing new artillery are prohibitive in a country of South Africa's size. it will be argued that it is necessary and possible, in the short term, to take what is currently available and adapt this to South Africa's needs.

  3. African horse sickness.

    Science.gov (United States)

    Mellor, Philip Scott; Hamblin, Christopher

    2004-01-01

    African horse sickness virus (AHSV) causes a non-contagious, infectious insect-borne disease of equids and is endemic in many areas of sub-Saharan Africa and possibly Yemen in the Arabian Peninsula. However, periodically the virus makes excursions beyond its endemic areas and has at times extended as far as India and Pakistan in the east and Spain and Portugal in the west. The vectors are certain species of Culicoides biting midge the most important of which is the Afro-Asiatic species C. imicola. This paper describes the effects that AHSV has on its equid hosts, aspects of its epidemiology, and present and future prospects for control. The distribution of AHSV seems to be governed by a number of factors including the efficiency of control measures, the presence or absence of a long term vertebrate reservoir and, most importantly, the prevalence and seasonal incidence of the major vector which is controlled by climate. However, with the advent of climate-change the major vector, C. imicola, has now significantly extended its range northwards to include much of Portugal, Spain, Italy and Greece and has even been recorded from southern Switzerland. Furthermore, in many of these new locations the insect is present and active throughout the entire year. With the related bluetongue virus, which utilises the same vector species of Culicoides this has, since 1998, precipitated the worst outbreaks of bluetongue disease ever recorded with the virus extending further north in Europe than ever before and apparently becoming endemic in that continent. The prospects for similar changes in the epidemiology and distribution of AHSV are discussed.

  4. Obesity and African Americans

    Science.gov (United States)

    ... Data > Minority Population Profiles > Black/African American > Obesity Obesity and African Americans African American women have the ... ss6304.pdf [PDF | 3.38MB] HEALTH IMPACT OF OBESITY More than 80 percent of people with type ...

  5. Comparative analysis of the complete genome sequence of the California MSW strain of myxoma virus reveals potential host adaptations.

    Science.gov (United States)

    Kerr, Peter J; Rogers, Matthew B; Fitch, Adam; Depasse, Jay V; Cattadori, Isabella M; Hudson, Peter J; Tscharke, David C; Holmes, Edward C; Ghedin, Elodie

    2013-11-01

    Myxomatosis is a rapidly lethal disease of European rabbits that is caused by myxoma virus (MYXV). The introduction of a South American strain of MYXV into the European rabbit population of Australia is the classic case of host-pathogen coevolution following cross-species transmission. The most virulent strains of MYXV for European rabbits are the Californian viruses, found in the Pacific states of the United States and the Baja Peninsula, Mexico. The natural host of Californian MYXV is the brush rabbit, Sylvilagus bachmani. We determined the complete sequence of the MSW strain of Californian MYXV and performed a comparative analysis with other MYXV genomes. The MSW genome is larger than that of the South American Lausanne (type) strain of MYXV due to an expansion of the terminal inverted repeats (TIRs) of the genome, with duplication of the M156R, M154L, M153R, M152R, and M151R genes and part of the M150R gene from the right-hand (RH) end of the genome at the left-hand (LH) TIR. Despite the extreme virulence of MSW, no novel genes were identified; five genes were disrupted by multiple indels or mutations to the ATG start codon, including two genes, M008.1L/R and M152R, with major virulence functions in European rabbits, and a sixth gene, M000.5L/R, was absent. The loss of these gene functions suggests that S. bachmani is a relatively recent host for MYXV and that duplication of virulence genes in the TIRs, gene loss, or sequence variation in other genes can compensate for the loss of M008.1L/R and M152R in infections of European rabbits.

  6. A Polymorphism in the Regulatory Region of the CC-Chemokine Receptor 5 Gene Influences Perinatal Transmission of Human Immunodeficiency Virus Type 1 to African-American Infants

    OpenAIRE

    1999-01-01

    There are natural mutations in the coding and noncoding regions of the human immunodeficiency virus type 1 (HIV-1) CC-chemokine coreceptor 5 (CCR5) and in the related CCR2 protein (the CCR2-64I mutation). Individuals homozygous for the CCR5-Δ32 allele, which prevents CCR5 expression, strongly resist HIV-1 infection. Several genetic polymorphisms have been identified within the CCR5 5′ regulatory region, some of which influence the rate of disease progression in adult AIDS study cohorts. We ge...

  7. Distemper outbreak and its effect on African wild dog conservation.

    NARCIS (Netherlands)

    M.W.G. van de Bildt (Marco); T. Kuiken (Thijs); A.M. Visee; S. Lema; A.R. Fitzjohn; A.D.M.E. Osterhaus (Albert)

    2002-01-01

    textabstractIn December 2000, an infectious disease spread through a captive breeding group of African wild dogs (Lycaon pictus) in Tanzania, killing 49 of 52 animals within 2 months. The causative agent was identified as Canine distemper virus (CDV) by means of histologic examination, virus isolati

  8. Adaptive Immune Responses in a Multiple Sclerosis Patient with Acute Varicella-Zoster Virus Reactivation during Treatment with Fingolimod

    Directory of Open Access Journals (Sweden)

    Andrea Harrer

    2015-09-01

    Full Text Available Fingolimod, an oral sphingosine 1-phosphate (S1P receptor modulator, is approved for the treatment of relapsing forms of multiple sclerosis (MS. The interference with S1P signaling leads to retention particularly of chemokine receptor-7 (CCR7 expressing T cells in lymph nodes. The immunological basis of varicella zoster virus (VZV infections during fingolimod treatment is unclear. Here, we studied the dynamics of systemic and intrathecal immune responses associated with symptomatic VZV reactivation including cessation of fingolimod and initiation of antiviral therapy. Key features in peripheral blood were an about two-fold increase of VZV-specific IgG at diagnosis of VZV reactivation as compared to the previous months, a relative enrichment of effector CD4+ T cells (36% versus mean 12% in controls, and an accelerated reconstitution of absolute lymphocytes counts including a normalized CD4+/CD8+ ratio and reappearance of CCR7+ T cells. In cerebrospinal fluid (CSF the lymphocytic pleocytosis and CD4+/CD8+ ratios at diagnosis of reactivation and after nine days of fingolimod discontinuation remained unchanged. During this time CCR7+ T cells were not observed in CSF. Further research into fingolimod-associated VZV reactivation and immune reconstitution is mandatory to prevent morbidity and mortality associated with this potentially life-threatening condition.

  9. Correction: Graillot, B.; et al. Progressive Adaptation of a CpGV Isolate to Codling Moth Populations Resistant to CpGV-M. Viruses 2014, 6, 5135–5144

    Directory of Open Access Journals (Sweden)

    Benoît Graillot

    2015-12-01

    Full Text Available In our article “Progressive Adaptation of a CpGV Isolate to Codling Moth Populations Resistant to CpGV-M.” (Viruses 2014, 6, 5135–5144; doi:10.3390/v6125135 [1] we obtained resistance values of the codling moth, Cydia pomonella, RGV laboratory colony [2], when challenged with Cydia pomonella Granulovirus, Mexican Isolate (CpGV-M, that were lower than those previously published [2]. Careful analysis of both the RGV colony and the CpGV-M virus stock used led to the realization that a low level contamination of this virus stock with CpGV-R5 occurred. We have made new tests with a verified stock, and the results are now in agreement with those previously published.

  10. [Ebola virus disease].

    Science.gov (United States)

    Nazimek, Katarzyna; Bociaga-Jasik, Monika; Bryniarski, Krzysztof; Gałas, Aleksander; Garlicki, Aleksander; Gawda, Anna; Gawlik, Grzegorz; Gil, Krzysztof; Kosz-Vnenchak, Magdalena; Mrozek-Budzyn, Dorota; Olszanecki, Rafał; Piatek, Anna; Zawilińska, Barbara; Marcinkiewicz, Janusz

    2014-01-01

    Ebola is one of the most virulent zoonotic RNA viruses causing in humans haemorrhagic fever with fatality ratio reaching 90%. During the outbreak of 2014 the number of deaths exceeded 8.000. The "imported" cases reported in Western Europe and USA highlighted the extreme risk of Ebola virus spreading outside the African countries. Thus, haemorrhagic fever outbreak is an international epidemiological problem, also due to the lack of approved prevention and therapeutic strategies. The editorial review article briefly summarizes current knowledge on Ebola virus disease epidemiology, etiology, pathogenesis, clinical presentation, diagnosis as well as possible prevention and treatment.

  11. Bioenergy and African transformation.

    Science.gov (United States)

    Lynd, Lee R; Sow, Mariam; Chimphango, Annie Fa; Cortez, Luis Ab; Brito Cruz, Carlos H; Elmissiry, Mosad; Laser, Mark; Mayaki, Ibrahim A; Moraes, Marcia Afd; Nogueira, Luiz Ah; Wolfaardt, Gideon M; Woods, Jeremy; van Zyl, Willem H

    2015-01-01

    Among the world's continents, Africa has the highest incidence of food insecurity and poverty and the highest rates of population growth. Yet Africa also has the most arable land, the lowest crop yields, and by far the most plentiful land resources relative to energy demand. It is thus of interest to examine the potential of expanded modern bioenergy production in Africa. Here we consider bioenergy as an enabler for development, and provide an overview of modern bioenergy technologies with a comment on application in an Africa context. Experience with bioenergy in Africa offers evidence of social benefits and also some important lessons. In Brazil, social development, agricultural development and food security, and bioenergy development have been synergistic rather than antagonistic. Realizing similar success in African countries will require clear vision, good governance, and adaptation of technologies, knowledge, and business models to myriad local circumstances. Strategies for integrated production of food crops, livestock, and bioenergy are potentially attractive and offer an alternative to an agricultural model featuring specialized land use. If done thoughtfully, there is considerable evidence that food security and economic development in Africa can be addressed more effectively with modern bioenergy than without it. Modern bioenergy can be an agent of African transformation, with potential social benefits accruing to multiple sectors and extending well beyond energy supply per se. Potential negative impacts also cut across sectors. Thus, institutionally inclusive multi-sector legislative structures will be more effective at maximizing the social benefits of bioenergy compared to institutionally exclusive, single-sector structures.

  12. Adaptive mutations enhance assembly and cell-to-cell transmission of a high-titer hepatitis C virus genotype 5a Core-NS2 JFH1-based recombinant

    DEFF Research Database (Denmark)

    Mathiesen, Christian K; Prentoe, Jannick; Meredith, Luke W;

    2015-01-01

    -NS5B viruses as well as viruses with only p7 and nonstructural protein mutations. Interestingly, the E2 hypervariable region 1 (HVR1) mutation T385P caused (i) increased sensitivity to neutralizing patient IgG and human monoclonal antibodies AR3A and AR4A and (ii) increased accessibility of the CD81......UNLABELLED: Recombinant hepatitis C virus (HCV) clones propagated in human hepatoma cell cultures yield relatively low infectivity titers. Here, we adapted the JFH1-based Core-NS2 recombinant SA13/JFH1C3405G,A3696G (termed SA13/JFH1orig), of the poorly characterized genotype 5a, to Huh7.5 cells......, yielding a virus with greatly improved spread kinetics and an infectivity titer of 6.7 log10 focus-forming units (FFU)/ml. We identified several putative adaptive amino acid changes. In head-to-head infections at fixed multiplicities of infection, one SA13/JFH1orig mutant termed SA13/JFH1Core-NS5B...

  13. African swine fever: an epidemiological update.

    Science.gov (United States)

    Sánchez-Vizcaíno, J M; Mur, L; Martínez-López, B

    2012-03-01

    African swine fever (ASF) is one of the most important swine diseases, mainly because of its significant sanitary and socioeconomic consequences. This review gives an update on the epidemiology of the disease and reviews key issues and strategies to improve control of the disease and promote its eradication. Several characteristics of ASF virus (ASFV) make its control and eradication difficult, including the absence of available vaccines, marked virus resistance in infected material and contaminated animal products, and a complex epidemiology and transmission involving tick reservoir virus interactions. The incidence of ASF has not only increased on the African continent over the last 15 years, so that it now affects West African countries, Mauritius and Madagascar, but it has also reached new areas, such as the Caucasus region in 2007. In fact, the rapid spread of the disease on the European continent and the uncontrolled situation in the Russian Federation places all countries at great risk as a result of intense global trade. The proximity of some affected areas to the European Union (EU) borders (African swine fever -free countries should be aware of the potential risk of ASF incursion and implement risk reduction measures such as trade controls and other sanitary measures. This review will discuss lessons learnt so far about ASF control, current challenges to its control and future studies needed to support global efforts at prevention and control.

  14. Real-Time Fluorescence Quantitative PCR for the Detection of African Swine Fever Virus%非洲猪瘟病毒TaqMan探针实时荧光定量PCR检测方法的建立

    Institute of Scientific and Technical Information of China (English)

    李维彬; 蒋正军; 王玉炯; 龚振华; 许崇波; 郭福生; 郑增忍

    2007-01-01

    为建立一种快速、准确、特异的非洲猪瘟病毒(African Swine Fever Virus,ASFV)定量检测方法,根据TaqMan探针荧光定量分析原理,对ASFV核酸进行了实时荧光定量PCR分析.借助计算机软件辅助,对ASFV基因序列及检测引物和探针进行了优化筛选,利用pET-ASFVP72质粒作为参比模板对PCR反应的Mg2+、引物、探针浓度等参数进行了优化,其最佳浓度分别为4.5 mmol/L,400 nnol/L和500 nmol/L.同时,对灵敏度、特异性、定量线性关系、精确度等进行了评估,最低检出量为102个拷贝数的质粒,特异性为100%,CT(Cycle Threshold)值的变异系数CV小于5%.对送检的15份(是否感染ASFV不确定)猪肉样品进行检测,结果全为阴性.试验表明,所建立的实时荧光定量PCR检测方法能够快速、准确、特异、灵敏地对ASFV核酸进行定量分析,从而为非洲猪瘟的检测提供了一个新的、可靠的方法.

  15. Elevation of soluble intercellular adhesion molecule-1 levels, but not angiopoietin 2, in the plasma of human immunodeficiency virus-infected African women with clinical Kaposi sarcoma.

    Science.gov (United States)

    Graham, Susan M; Rajwans, Nimerta; Richardson, Barbra A; Jaoko, Walter; McClelland, R Scott; Overbaugh, Julie; Liles, W Conrad

    2014-10-01

    Circulating levels of endothelial activation biomarkers are elevated in during infection with human immunodeficiency virus 1 (HIV-1) and may also be increased in Kaposi sarcoma (KS). We compared 23 HIV-1-seropositive women with clinically diagnosed KS with 46 randomly selected controls matched for visit year, CD4 count, and antiretroviral therapy status. Conditional logistic regression was used to identify differences between cases and controls. The odds of clinical KS increased with increasing plasma viral load and with intercellular adhesion molecule 1 (ICAM-1) levels above or equal to the median. There was a borderline association between increasing plasma angiopoietin 2 levels and KS. In multivariable modeling including plasma viral load, angiopoietin 2, and ICAM-1, plasma ICAM-1 levels above or equal to the median remained associated with clinical KS (odds ratio = 14.2, 95% confidence interval = 2.3-87.7). Circulating ICAM-1 levels should be evaluated as a potential biomarker for disease progression and treatment response among HIV-infected KS patients.

  16. Serological and genetic characterisation of bovine respiratory syncytial virus (BRSV) indicates that Danish isolates belong to the intermediate subgroup: no evidence of a selective effect on the variability of G protein nucleotide sequence by prior cell culture adaption and passages in cell culture

    DEFF Research Database (Denmark)

    Larsen, Lars Erik; Uttenthal, Åse; Arctander, P.;

    1998-01-01

    part of the G gene of additional 11 field BRSV viruses, processed directly from lung samples without prior adaption to cell culture growth. revealed sequence variabilities in the range obtained with the propagated virus. In addition, several passages in cell culture and in calves had no major impact...

  17. African swine fever : transboundary diseases

    Directory of Open Access Journals (Sweden)

    M-L. Penrith

    2009-09-01

    Full Text Available African swine fever (ASF is a devastating haemorrhagic fever of pigs that causes up to 100 % mortality, for which there is no vaccine. It is caused by a unique DNA virus that is maintained in an ancient cycle between warthogs and argasid ticks, making it the only known DNA arbovirus. ASF has a high potential for transboundary spread, and has twice been transported from Africa to other continents - Europe and subsequently the Caribbean and Brazil (1957, 1959 and the Caucasus (2007. It is also a devastating constraint for pig production in Africa. Research at Onderstepoort Veterinary Institute has made and is making important contributions to knowledge of this disease, focusing on the cycle in warthogs and tampans and transmission from that cycle to domestic pigs, resistance to its effects in domestic pigs, and the molecular genetic characterisation and epidemiology of the virus.

  18. Interspecies transmission and chikungunya virus emergence.

    Science.gov (United States)

    Tsetsarkin, Konstantin A; Chen, Rubing; Weaver, Scott C

    2016-02-01

    Chikungunya virus (CHIKV) causes severe, debilitating, often chronic arthralgia with high attack rates, resulting in severe morbidity and economic costs to affected communities. Since its first well-documented emergence in Asia in the 1950s, CHIKV has infected millions and, since 2007, has spread widely, probably via viremic travelers, to initiate urban transmission in Europe, the South Pacific, and the Americas. Some spread has been facilitated by adaptive envelope glycoprotein substitutions that enhance transmission by the new vector, Aedes albopictus. Although epistatic constraints may prevent the impact of these mutations in Asian strains now circulating in the Americas, as well as in African CHIKV strains imported into Brazil last year, these constraints could eventually be overcome over time to increase the transmission by A. albopictus in rural and temperate regions. Another major determinant of CHIKV endemic stability in the Americas will be its ability to spill back into an enzootic cycle involving sylvatic vectors and nonhuman primates, an opportunity exploited by yellow fever virus but apparently not by dengue viruses.

  19. Heart Disease and African Americans

    Science.gov (United States)

    ... Minority Population Profiles > Black/African American > Heart Disease Heart Disease and African Americans Although African American adults are ... were 30 percent more likely to die from heart disease than non-Hispanic whites. African American women are ...

  20. 78 FR 67175 - Proposed Collection; 60-Day Comment Request: Incident HIV/Hepatitis B Virus Infections in South...

    Science.gov (United States)

    2013-11-08

    .../ Hepatitis B Virus Infections in South African Blood Donors: Behavioral Risk Factors, Genotypes and.../Hepatitis B virus (HBV) infections in South African blood donors: Behavioral risk factors, genotypes and... antigen detection tests) to screen blood donors for HIV and Hepatitis-B Virus (HBV), among...

  1. Depression and African Americans

    Science.gov (United States)

    ... You are here Home » Depression And African Americans Depression And African Americans Not “Just the Blues” Clinical ... or spiritual communities. Commonly Asked Questions about Clinical Depression How do I get help for clinical depression? ...

  2. Identification of amino acid changes in the envelope glycoproteins of bovine viral diarrhea viruses isolated from alpaca that may be involved in host adaptation

    Science.gov (United States)

    Bovine viral diarrhea viruses (BVDV) are most commonly associated with infections of cattle. However, BVDV is often isolated from closely related ruminants with a number of BVDV-1b viruses being isolated from alpacas that were both acutely and persistently infected (PI). The complete nucleotide se...

  3. Optimizing the Conditions of an Indirect ELISA for Detection of African Swine Fever Virus Antibody%ELISA法检测非洲猪瘟抗体实验条件的优化

    Institute of Scientific and Technical Information of China (English)

    张永强; 任伟杰; 吴晓东; 王筱真; 李金明; 王志亮

    2014-01-01

    In the study,the effects of antigen coating concentration,enzyme labeled antibody and chromogenic sub-strate in an ELISA with inactivated African swine fever virus as coating antigen were analyzed for detection of ASFV antibody. In order to obtain the optimum reaction conditions,different coating antigen concentrations,2 type enzyme-labeled antibody and 2 type chromogenic substrates were used in the ELISA to detect 2 positive serum samples and 1 negative serum sample. The result showed that the optimum reaction conditions were:the antigen coating concentration was 15μg/mL;Protein A-HRP was used as labeled antibody,and OPD as chromogenic substrate and the P/N value of 2 positive serum samples were 4.920 and 7.259.%本文以灭活非洲猪瘟病毒为包被抗原,分析了包被浓度、酶标二抗、显色底物对ELISA法检测非洲猪瘟抗体的影响,以期获得最适反应条件。以2个阳性血清和一个阴性血清为待检样品,用不同包被浓度、2种酶标二抗和2种显色底物进行ELISA反应,记录吸光值,分析阴阳性样品吸光值差异,优化阴性样品背景值,计算P/N值。结果表明,包被浓度为15µg/mL、二抗为HRP标记蛋白A、显色底物为OPD时,两个阳性样品P/N值分别为4.920和7.259,为本方法的最适反应条件。

  4. 非洲猪瘟病毒VP73结构蛋白表达及鉴定%Expression and identification of structural protein VP73 of African swine fever virus

    Institute of Scientific and Technical Information of China (English)

    董林; 王艳萍; 张春玲; 沈志强

    2013-01-01

    According to the gene sequence of African swine fever virus (ASFV) VP73 in the GenBank,the gene fragment of major antigenic epitope of VP73 was synthesized and cloned into pUC57 vector.The VP73 gene of ASFV amplified from recombinant pUC57 by PCR,and the product was a 429 bp DNA fragment.The purified VP73 gene fragment was subcloned into pGEX-KG vector by EcoRI and SalI enzymes digestion.The recombinant plasmid was identified by PCR and enzymes digestion.It was sequenced to confirm the correct sequences and the correct junctional orientations of the inserted VP73 gene.The recombinant plasmid was transformed into BL21 (DM3).The recombinant protein was induced to express by IPTG,and then was analyze by SDS-PAEG and Western blot.The results showed the recombinant plasmid was successfully constructed.The results of SDS-PAGE revealed that the VP73 protein with a molecular mass of approximately 41ku was expressed,which was up to 17% of total bacterial protein.Western blotting analysis revealed good immunoreactivity.%根据GenBank登录的非洲猪瘟病毒(ASFV) VP73基因序列,人工合成VP73主要抗原表位区基因片段,克隆至pUC57载体中.设计1对引物,PCR扩增获得429 bp的VP73基因片段;将VP73基因片段使用EcoRI和SalI酶切后亚克隆至表达载体pGEX-KG,经PCR、酶切、测序鉴定挑选阳性克隆,转化至表达菌株BL21 (DM3)中,进行体外诱导表达,SDS-PAGE和Western blot分析蛋白表达及其活性.结果显示,成功构建表达重组载体pGEX-KG-VP73,对该重组载体进行诱导,有效表达了41 ku重组蛋白,表达量约占菌体总蛋白的17%,Western blot分析证实该蛋白具有良好反应原性.

  5. Linguistic Imperialism: African Perspectives.

    Science.gov (United States)

    Phillipson, Robert

    1996-01-01

    Responds to an article on aspects of African language policy and discusses the following issues: multilingualism and monolingualism, proposed changes in language policy from the Organization for African Unity and South African initiatives, the language of literature, bilingual education, and whose interests English-language teaching is serving.…

  6. Single amino acid changes in the 6K1-CI region can promote the alternative adaptation of Prunus- and Nicotiana-propagated Plum pox virus C isolates to either host.

    Science.gov (United States)

    Calvo, María; Malinowski, Tadeusz; García, Juan Antonio

    2014-02-01

    Plum pox virus (PPV) C is one of the less common PPV strains and specifically infects cherry trees in nature. Making use of two PPV-C isolates that display different pathogenicity features, i.e., SwCMp, which had been adapted to Nicotiana species, and BY101, which had been isolated from cherry rootstock L2 (Prunus lannesiana) and propagated only in cherry species, we have generated two infective full-length cDNA clones in order to determine which viral factors are involved in the adaptation to each host. According to our results, the C-P3(PIPO)/6K1/N-CI (cylindrical inclusion) region contains overlapping but not coincident viral determinants involved in symptoms development, local viral amplification, and systemic movement capacity. Amino acid changes in this region promoting the adaptation to N. benthamiana or P. avium have trade-off effects in the alternative host. In both cases, adaptation can be achieved through single amino acid changes in the NIapro protease recognition motif between 6K1 and CI or in nearby sequences. Thus, we hypothesize that the potyvirus polyprotein processing could depend on specific host factors and the adaptation of PPV-C isolates to particular hosts relies on a fine regulation of the proteolytic cleavage of the 6K1-CI junction.

  7. Exceptionally diverse morphotypes and genomes of crenarchaeal hyperthermophilic viruses

    DEFF Research Database (Denmark)

    Prangishvili, D; Garrett, R A

    2004-01-01

    crenarchaeal rudiviruses and the large eukaryal DNA viruses: poxviruses, the African swine fever virus and Chlorella viruses. Sequence patterns at the ends of the linear genome of the lipothrixvirus AFV1 are reminiscent of the telomeric ends of linear eukaryal chromosomes and suggest that a primitive telomeric...

  8. Viral hemorrhagic fevers of animals caused by DNA viruses

    Science.gov (United States)

    Here we outline serious diseases of food and fiber animals that cause damaging economic effect on products all over the world. The only vector-borne DNA virus is included here, such as African swine fever virus, and the herpes viruses discussed have a complex epidemiology characterized by outbreak...

  9. Adaptation of Soybean mosaic virus avirulent chimeras containing P3 sequences from virulent strains to Rsv1-genotype soybeans is mediated by mutations in HC-Pro.

    Science.gov (United States)

    Hajimorad, M R; Eggenberger, A L; Hill, J H

    2008-07-01

    In Rsv1-genotype soybean, Soybean mosaic virus (SMV)-N (an avirulent isolate of strain G2) elicits extreme resistance (ER) whereas strain SMV-G7 provokes a lethal systemic hypersensitive response (LSHR). SMV-G7d, an experimentally evolved variant of SMV-G7, induces systemic mosaic. Thus, for Rsv1-genotype soybean, SMV-N is avirulent whereas SMV-G7 and SMV-G7d are both virulent. Exploiting these differential interactions, we recently mapped the elicitor functions of SMV provoking Rsv1-mediated ER and LSHR to the N-terminal 271 amino acids of P3 from SMV-N and SMV-G7, respectively. The phenotype of both SMV-G7 and SMV-G7d were rendered avirulent on Rsv1-genotype soybean when the part of the genome encoding the N-terminus or the entire P3 cistron was replaced with that from SMV-N; however, reciprocal exchanges did not confer virulence to SMV-N-derived P3 chimeras. Here, we describe virulent SMV-N-derived P3 chimeras containing the full-length or the N-terminal P3 from SMV-G7 or SMV-G7d, with or without additional mutations in P3, that were selected on Rsv1-genotype soybean by sequential transfers on rsv1 and Rsv1-genotype soybean. Sequence analyses of the P3 and helper-component proteinase (HC-Pro) cistrons of progeny recovered from Rsv1-genotype soybean consistently revealed the presence of mutations in HC-Pro. Interestingly, the precise mutations in HC-Pro required for the adaptation varied among the chimeras. No mutation was detected in the HC-Pro of progeny passaged continuously in rsv1-genotype soybean, suggesting that selection is a consequence of pressure imposed by Rsv1. Mutations in HC-Pro alone failed to confer virulence to SMV-N; however, reconstruction of mutations in HC-Pro of the SMV-N-derived P3 chimeras resulted in virulence. Taken together, the data suggest that HC-Pro complementation of P3 is essential for SMV virulence on Rsv1-genotype soybean.

  10. A New Definition of Virus

    Institute of Scientific and Technical Information of China (English)

    HE Hongjun; CAO Sihua; LUO Li; FENG Tao; PAN Li; ZOU Zhiji

    2006-01-01

    Security experts have not formally defined the distinction between viruses and normal programs. The paper takes user's intension as the criteria for malice, gives a formal definition of viruses that aim at stealing or destroying files, and proposes an algorithm to detect virus correctly. Compared with traditional definitions, this new definition is easy to understand, covers more malwares, adapts development of virus technology, and defines virus on the spot. The paper has also analyzed more than 250 real viruses and finds that they are all in the domain of the new definition, this implies that the new definition has great practical significance.

  11. The molecular and cellular aspects of arthritis due to alphavirus infections: lesson learned from Ross River virus.

    Science.gov (United States)

    Rulli, Nestor E; Melton, Julian; Wilmes, Anja; Ewart, Gary; Mahalingam, Suresh

    2007-04-01

    Alphaviruses such as the Sindbis-group viruses, Scandinavian Ockelbo virus, the African Asian chikungunya virus, the African O'nyong-nyong virus, the South American Mayaro virus, and the Australasian Barmah Forest and Ross River viruses, are commonly associated with outbreaks of acute and persistent arthritis and arthralgia in humans. The mechanisms by which these viruses cause arthritis/arthralgia are poorly understood. This chapter summarizes our current understanding of viral arthritides using our newly developed mouse model of Ross River virus-induced joint and muscle inflammation.

  12. Sequence adaptations affecting cleavage of the VP1/2A junction by the 3C protease in foot-and-mouth disease virus-infected cells

    DEFF Research Database (Denmark)

    Gullberg, Maria; Polacek, Charlotta; Belsham, Graham

    2014-01-01

    The foot-and-mouth disease virus (FMDV) capsid protein precursor P1-2A is cleaved by the virus-encoded 3C protease to VP0, VP3, VP1 and 2A. It was shown previously that modification of a single amino acid residue (K210E) within the VP1 protein and close to the VP1/2A cleavage site, inhibited clea...

  13. Dengue type four viruses with E-Glu345Lys adaptive mutation from MRC-5 cells induce low viremia but elicit potent neutralizing antibodies in rhesus monkeys.

    Science.gov (United States)

    Lin, Hsiao-Han; Lee, Hsiang-Chi; Li, Xiao-Feng; Tsai, Meng-Ju; Hsiao, Hung-Ju; Peng, Jia-Guan; Sue, Shih-Che; Qin, Cheng-Feng; Wu, Suh-Chin

    2014-01-01

    Knowledge of virulence and immunogenicity is important for development of live-attenuated dengue vaccines. We previously reported that an infectious clone-derived dengue type 4 virus (DENV-4) passaged in MRC-5 cells acquired a Glu345Lys (E-E345K) substitution in the E protein domain III (E-DIII). The same cloned DENV-4 was found to yield a single E-Glu327Gly (E-E327G) mutation after passage in FRhL cells and cause the loss of immunogenicity in rhesus monkeys. Here, we used site-directed mutagenesis to generate the E-E345K and E-E327G mutants from DENV-4 and DENV-4Δ30 infectious clones and propagated in Vero or MRC-5 cells. The E-E345K mutations were consistently presented in viruses recovered from MRC-5 cells, but not Vero cells. Recombinant E-DIII proteins of E345K and E327G increased heparin binding correlated with the reduced infectivity by heparin treatment in cell cultures. Different from the E-E327G mutant viruses to lose the immunogencity in rhesus monkeys, the E-E345K mutant viruses were able to induce neutralizing antibodies in rhesus monkeys with an almost a 10-fold lower level of viremia as compared to the wild type virus. Monkeys immunized with the E-E345K mutant virus were completely protected with no detectable viremia after live virus challenges with the wild type DENV-4. These results suggest that the E-E345K mutant virus propagated in MRC-5 cells may have potential for the use in live-attenuated DENV vaccine development.

  14. Population Genomics of sub-saharan Drosophila melanogaster: African diversity and non-African admixture.

    Directory of Open Access Journals (Sweden)

    John E Pool

    Full Text Available Drosophila melanogaster has played a pivotal role in the development of modern population genetics. However, many basic questions regarding the demographic and adaptive history of this species remain unresolved. We report the genome sequencing of 139 wild-derived strains of D. melanogaster, representing 22 population samples from the sub-Saharan ancestral range of this species, along with one European population. Most genomes were sequenced above 25X depth from haploid embryos. Results indicated a pervasive influence of non-African admixture in many African populations, motivating the development and application of a novel admixture detection method. Admixture proportions varied among populations, with greater admixture in urban locations. Admixture levels also varied across the genome, with localized peaks and valleys suggestive of a non-neutral introgression process. Genomes from the same location differed starkly in ancestry, suggesting that isolation mechanisms may exist within African populations. After removing putatively admixed genomic segments, the greatest genetic diversity was observed in southern Africa (e.g. Zambia, while diversity in other populations was largely consistent with a geographic expansion from this potentially ancestral region. The European population showed different levels of diversity reduction on each chromosome arm, and some African populations displayed chromosome arm-specific diversity reductions. Inversions in the European sample were associated with strong elevations in diversity across chromosome arms. Genomic scans were conducted to identify loci that may represent targets of positive selection within an African population, between African populations, and between European and African populations. A disproportionate number of candidate selective sweep regions were located near genes with varied roles in gene regulation. Outliers for Europe-Africa F(ST were found to be enriched in genomic regions of locally

  15. 非洲猪瘟病毒环介导恒温扩增快速检测技术的建立及应用%DEVELOPMENT OF LOOP-MEDIATED ISOTHERMAL AMPLIFICATION (LAMP) FOR RAPID DETECTION OF AFRICAN SWINE FEVER VIRUS

    Institute of Scientific and Technical Information of China (English)

    杨吉飞; 杜鹏飞; 罗建勋; 殷宏; 关贵全; 刘志杰; 汪月凤; 李有全; 马米玲; 刘爱红; 任巧云; 苟惠天

    2011-01-01

    本研究基于非洲猪瘟病毒(African swine fever virus, ASFV)vp72基因设计引物,建立了能够快速检测非洲猪瘟病毒的环介导恒温扩增技术(loop-mediated isothermal amplification, LAMP)。将LAMP与OIE参考的PCR检测方法进行比较,并且应用LAMP对非洲猪瘟参考实验室提供的非洲猪瘟病毒17个毒株的基因组以及国内收集的50份猪的基因组、30份蜱的基因组进行检测。结果显示,本研究设计的引物具有良好的特异性和敏感性,所建立的LAMP能够成功扩增非洲猪瘟病毒17个毒株的基因组,而野外收集的猪和蜱的基因组检测均为阴性。因此,本研究所建立的方法能够用于非洲猪瘟的快速诊断以及防控。%A loop-mediated isothermal amplification (LAMP) rapid assay was developed for detecting African swine fever virus (ASFV) based on the vp72 gene. This method was compared to the PCR which was recommended by OIE. Seventeen genomic DNAs of ASFV isolates from African swine fever reference laboratory, 50 field pig samples and 30 field tick samples from China were detected by LAMP, respectively. Seventeen genomic DNAs of ASFV isolates could be detected successfully, but all of the field samples were negative. The result revealed that this method had a good specificity and sensitivity, which could be used in rapid diagnosis, prevention and control of African swine fever.

  16. Health evaluation of African penguins (Spheniscus demersus) in southern Africa.

    Science.gov (United States)

    Parsons, Nola J; Gous, Tertius A; Schaefer, Adam M; Vanstreels, Ralph E T

    2016-09-20

    The African penguin (Spheniscus demersus) is an endangered seabird that breeds along the coast of Namibia and South Africa, and disease surveillance was identified as a priority for its conservation. Aiming for the establishment of baseline data on the presence of potential pathogens in this species, a comprehensive health assessment (blood smear examination, haematology, biochemistry and serology) was conducted on samples obtained from 578 African penguins at 11 breeding colonies and a rehabilitation centre. There were 68 penguins that were seropositive for at least one of seven pathogens tested: avian encephalomyelitis virus, avian infectious bronchitis virus, avian reovirus, infectious bursal disease virus, Newcastle disease virus, Mycoplasma gallisepticum and Mycoplasma synoviae. All samples were seronegative for avian influenza virus subtypes H5 and H7 and infectious laryngotracheitis virus. The apparent prevalence of Babesia sp. and Borrelia sp. in blood smears was consistent with previous studies. Babesia-infected individuals had a regenerative response of the erythrocytic lineage, an active inflammatory response and hepatic function impairment. These findings indicate that African penguins may be exposed to conservation-significant pathogens in the wild and encourage further studies aiming for the direct detection and/or isolation of these microorganisms.

  17. Health evaluation of African penguins (Spheniscus demersus in southern Africa

    Directory of Open Access Journals (Sweden)

    Nola J. Parsons

    2016-03-01

    Full Text Available The African penguin (Spheniscus demersus is an endangered seabird that breeds along the coast of Namibia and South Africa, and disease surveillance was identified as a priority for its conservation. Aiming for the establishment of baseline data on the presence of potential pathogens in this species, a comprehensive health assessment (blood smear examination, haematology, biochemistry and serology was conducted on samples obtained from 578 African penguins at 11 breeding colonies and a rehabilitation centre. There were 68 penguins that were seropositive for at least one of seven pathogens tested: avian encephalomyelitis virus, avian infectious bronchitis virus, avian reovirus, infectious bursal disease virus, Newcastle disease virus, Mycoplasma gallisepticum and Mycoplasma synoviae. All samples were seronegative for avian influenza virus subtypes H5 and H7 and infectious laryngotracheitis virus. The apparent prevalence of Babesia sp. and Borrelia sp. in blood smears was consistent with previous studies. Babesia-infected individuals had a regenerative response of the erythrocytic lineage, an active inflammatory response and hepatic function impairment. These findings indicate that African penguins may be exposed to conservation-significant pathogens in the wild and encourage further studies aiming for the direct detection and/or isolation of these microorganisms.

  18. Mechanical properties of viruses.

    Science.gov (United States)

    de Pablo, Pedro J; Mateu, Mauricio G

    2013-01-01

    Structural biology techniques have greatly contributed to unveil the relationships between structure, properties and functions of viruses. In recent years, classic structural approaches are being complemented by single-molecule techniques such as atomic force microscopy and optical tweezers to study physical properties and functions of viral particles that are not accessible to classic structural techniques. Among these features are mechanical properties such as stiffness, intrinsic elasticity, tensile strength and material fatigue. The field of virus mechanics is contributing to materials science by investigating some physical parameters of "soft" biological matter and biological nano-objects. Virus mechanics studies are also starting to unveil the biological implications of physical properties of viruses. Growing evidence indicate that viruses are subjected to internal and external forces, and that they may have adapted to withstand and even use those forces. This chapter describes what is known on the mechanical properties of virus particles, their structural determinants, and possible biological implications, of which several examples are provided.

  19. Adaptability of Dengue-Ⅳ virus LD34 strain in KMB17 cells and biological characteristics of adapted strain%Ⅳ型登革病毒中国株LD34在KMB17细胞上的适应性及其生物学特性

    Institute of Scientific and Technical Information of China (English)

    赵玉娇; 龙海亭; 潘玥; 陈俊英; 杨丽娟; 岳耀斐; 孙强明

    2012-01-01

    目的 研究Ⅳ型登革病毒中国株LD34在人胚肺二倍体细胞KMB17上的传代适应性及其生物学特性.方法 将Ⅳ型登革病毒中国株LD34在C6/36细胞上扩增,并采用微量细胞病变法测定病毒的感染性滴度.以2.0 MOI的病毒接种KMB17细胞传代培养,筛选KMB17细胞适应株,并进行培养条件的优化.将Ⅳ型登革病毒中国株LD34 KMB17细胞适应株连续传10代,测定病毒的感染性滴度,免疫荧光法检测病毒的抗原性,RT-PCR法扩增登革病毒的特异性基因.结果 筛选出的Ⅳ型登革病毒中国株LD34在KMB17细胞上的最佳培养条件为病毒接种MOI 0.4,培养基血清浓度5%;其感染KMB17细胞后可产生明显的细胞病变(CPE),连续传10代,病毒滴度达7.75 CCID50/ml;第10代病毒的抗原性呈阳性;第10代病毒能扩增出511 bp的登革病毒特异性基因和393 bp的Ⅳ型登革病毒特异性基因.结论 获得了Ⅳ型登革病毒中国株LD34 KMB17细胞适应株,病毒保持了原始毒株的基本生物学特性,且具有较好的抗原性.%Objective To investigate the adaptability of Dengue-Ⅳ virus LD34 strain, isolated in China, in KMB17 cells and the biological characteristics of adapted strain. Methods Dengue-Ⅳ LD34 strain was propagated in C6/36 cells and determined for infectivity, then inoculated to KMB17 cells at a MOI of 2.0 for subculture, based on which the adapted strain was screened, and the culture condition was optimized. The adapted strain was subcultured in KMB17 cells for 10 passages, then determined for infectious titer by microtitrimetry, and for antigenicity by IFA, from which the specific gene was amplified by RT-PCR. Results The optimal MOI and serum concentration in medium for culture of the screened adapted strain were 0. 4 and 5% respectively. The adapted strain caused obvious CPE of KMB17 cells , and reached a titer of 7. 75 CCID50/ml after subculture for 10 passages. The virus of passage 10 was positive for

  20. Measles virus selectively blind to signaling lymphocytic activation molecule (SLAM; CD150) is attenuated and induces strong adaptive immune responses in rhesus monkeys.

    Science.gov (United States)

    Leonard, Vincent H J; Hodge, Gregory; Reyes-Del Valle, Jorge; McChesney, Michael B; Cattaneo, Roberto

    2010-04-01

    The signaling lymphocytic activation molecule (SLAM; CD150) is the immune cell receptor for measles virus (MV). To assess the importance of the SLAM-MV interactions for virus spread and pathogenesis, we generated a wild-type IC-B MV selectively unable to recognize human SLAM (SLAM-blind). This virus differs from the fully virulent wild-type IC-B strain by a single arginine-to-alanine substitution at amino acid 533 of the attachment protein hemagglutinin and infects cells through SLAM about 40 times less efficiently than the isogenic wild-type strain. Ex vivo, this virus infects primary lymphocytes at low levels regardless of SLAM expression. When a group of six rhesus monkeys (Macaca mulatta) was inoculated intranasally with the SLAM-blind virus, no clinical symptoms were documented. Only one monkey had low-level viremia early after infection, whereas all the hosts in the control group had high viremia levels. Despite minimal, if any, viremia, all six hosts generated neutralizing antibody titers close to those of the control monkeys while MV-directed cellular immunity reached levels at least as high as in wild-type-infected monkeys. These findings prove formally that efficient SLAM recognition is necessary for MV virulence and pathogenesis. They also suggest that the selectively SLAM-blind wild-type MV can be developed into a vaccine vector.

  1. Reading the African context

    Directory of Open Access Journals (Sweden)

    Musonda Bwalya

    2012-12-01

    Full Text Available There is so much alienation, pain and suffering in our today�s world. In this vein, African Christianity, a voice amongst many voices, should seek to be a transformational religion for the whole of life, affecting all facets of human life towards a fuller life of all in Africa. This article sought to highlight and point to some of the major societal challenges in the African context which African Christianity, as a life-affirming religion, should continue to embrace, re-embrace and engage with, if it has to be relevant to the African context. In this vein, the article argued that a correct reading of the African context would lead to a more relevant theory and praxis of African Christianity for the benefit of all African peoples and their global neighbours. The contention of this article was that African Christianity has a significant role to play in the re-shaping of the African society and in the global community of humans, only that this role must be executed inclusively, responsibly and appropriately, together with all those who seek the holistic development of Africa towards one common destiny.

  2. Gairo virus, a novel arenavirus of the widespread Mastomys natalensis: Genetically divergent, but ecologically similar to Lassa and Morogoro viruses.

    Science.gov (United States)

    Gryseels, Sophie; Rieger, Toni; Oestereich, Lisa; Cuypers, Bart; Borremans, Benny; Makundi, Rhodes; Leirs, Herwig; Günther, Stephan; Goüy de Bellocq, Joëlle

    2015-02-01

    Despite its near pan-African range, the Natal multimammate mouse, Mastomys natalensis, carries the human pathogen Lassa virus only in West Africa, while the seemingly non-pathogenic arenaviruses Mopeia, Morogoro, and Luna have been detected in this semi-commensal rodent in Mozambique/Zimbabwe, Tanzania and Zambia, respectively. Here, we describe a novel arenavirus in M. natalensis from Gairo district of central Tanzania, for which we propose the name "Gairo virus". Surprisingly, the virus is not closely related with Morogoro virus that infects M. natalensis only 90km south of Gairo, but clusters phylogenetically with Mobala-like viruses that infect non-M. natalensis host species in Central African Republic and Ethiopia. Despite the evolutionary distance, Gairo virus shares basic ecological features with the other M. natalensis-borne viruses Lassa and Morogoro. Our data show that M. natalensis, carrying distantly related viruses even in the same geographical area, is a potent reservoir host for a variety of arenaviruses.

  3. M2e-displaying virus-like particles with associated RNA promote T helper 1 type adaptive immunity against influenza A.

    Directory of Open Access Journals (Sweden)

    Lorena Itatí Ibañez

    Full Text Available The ectodomain of influenza A matrix protein 2 (M2e is a candidate for a universal influenza A vaccine. We used recombinant Hepatitis B core antigen to produce virus-like particles presenting M2e (M2e-VLPs. We produced the VLPs with and without entrapped nucleic acids and compared their immunogenicity and protective efficacy. Immunization of BALB/c mice with M2e-VLPs containing nucleic acids induced a stronger, Th1-biased antibody response compared to particles lacking nucleic acids. The former also induced a stronger M2e-specific CD4(+ T cell response, as determined by ELISPOT. Mice vaccinated with alum-adjuvanted M2e-VLPs containing the nucleic acid-binding domain were better protected against influenza A virus challenge than mice vaccinated with similar particles lacking this domain, as deduced from the loss in body weight following challenge with X47 (H3N2 or PR/8 virus. Challenge of mice that had been immunized with M2e-VLPs with or without nucleic acids displayed significantly lower mortality, morbidity and lung virus titers than control-immunized groups. We conclude that nucleic acids present in M2e-VLPs correlate with improved immune protection.

  4. Endomembrane Ca2+-AtPases play a significant role in virus-induced adaptation to oxidative stress

    DEFF Research Database (Denmark)

    Shabala, Sergey; Bækgaard, Lone; Shabala, Lana;

    2011-01-01

    Although the role of Ca2+ influx channels in oxidative stress signaling and cross-tolerance in plants is well established, little is known about the role of active Ca2+ efflux systems in this process. In our recent paper,17 we reported Potato Virus X (PVX)-induced acquired resistance to oxidative...

  5. The draft genome of whitefly Bemisia tabaci MEAM1, a global crop pest, provides novel insights into virus transmission, host adaptation, and insecticide resistance

    Science.gov (United States)

    Whiteflies are among the most important agricultural pests. They have a broad range of host plants and exceptional ability to transmit a large number of plant viruses, and can rapidly evolve insecticide resistance. Here we present a high-quality draft genome of the whitefly, Bemisia tabaci. Comparat...

  6. Empowering African States

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    China helps bring lasting peace and stability to Africa African think tanks expressed a high opinion of China’s role in helping build African peace and security at the first meeting of the China-Africa Think Tanks Forum. The

  7. African Literature as Celebration.

    Science.gov (United States)

    Achebe, Chinua

    1989-01-01

    Describes the Igbo tradition of "Mbari," a communal creative enterprise that celebrates the world and the life lived in it through art. Contrasts the cooperative, social dimension of pre-colonial African culture with the exclusion and denial of European colonialism, and sees new African literature again celebrating human presence and…

  8. African American Suicide

    Science.gov (United States)

    African American Suicide Fact Sheet Based on 2012 Data (2014) Overview • In 2012, 2,357 African Americans completed suicide in the U.S. Of these, 1,908 (80. ... rate of 9.23 per 100,000). The suicide rate for females was 1.99 per 100, ...

  9. African Peacekeepers in Africa

    DEFF Research Database (Denmark)

    Emmanuel, Nikolas G.

    2015-01-01

    behind African participation in United Nations (UN) peacekeeping operations in Africa. In doing so, this research focuses on US military aid and foreign troop training from 2002 to 2012, and its impact on African deployments into UN peacekeeping missions in Africa. As can be expected, such third...

  10. African agricultural trade

    DEFF Research Database (Denmark)

    Jensen, Hans Grinsted; Sandrey, Ron

    2015-01-01

    This article starts with a profile of African agricultural trade. Using the pre-release version 9.2 of the GTAP database, we then show that the results for tariff elimination on intra-African trade are promising, but these tariff barriers are not as significant as the various trade-related barriers...

  11. Zika virus infection damages the testes in mice.

    Science.gov (United States)

    Govero, Jennifer; Esakky, Prabagaran; Scheaffer, Suzanne M; Fernandez, Estefania; Drury, Andrea; Platt, Derek J; Gorman, Matthew J; Richner, Justin M; Caine, Elizabeth A; Salazar, Vanessa; Moley, Kelle H; Diamond, Michael S

    2016-12-15

    Infection of pregnant women with Zika virus (ZIKV) can cause congenital malformations including microcephaly, which has focused global attention on this emerging pathogen. In addition to transmission by mosquitoes, ZIKV can be detected in the seminal fluid of affected males for extended periods of time and transmitted sexually. Here, using a mouse-adapted African ZIKV strain (Dakar 41519), we evaluated the consequences of infection in the male reproductive tract of mice. We observed persistence of ZIKV, but not the closely related dengue virus (DENV), in the testis and epididymis of male mice, and this was associated with tissue injury that caused diminished testosterone and inhibin B levels and oligospermia. ZIKV preferentially infected spermatogonia, primary spermatocytes and Sertoli cells in the testis, resulting in cell death and destruction of the seminiferous tubules. Less damage was caused by a contemporary Asian ZIKV strain (H/PF/2013), in part because this virus replicates less efficiently in mice. The extent to which these observations in mice translate to humans remains unclear, but longitudinal studies of sperm function and viability in ZIKV-infected humans seem warranted.

  12. Genetic diversity of Chikungunya virus, India 2006-2010: evolutionary dynamics and serotype analyses.

    Science.gov (United States)

    Sumathy, K; Ella, Krishna M

    2012-03-01

    The genetic diversity of Chikungunya virus (CHIKV) causing recurring outbreaks in India since 2006 was studied. The 2006 epidemic was caused by a virus strain of the East, Central and South African (ECSA) genotype with 226A in the E1 glycoprotein. The variant strain with E1-A226V mutation caused outbreaks since 2007 in the state of Kerala where Aedes albopictus is the abundant mosquito vector. Molecular epidemiology data since 2007 is scarce from other regions of the country. RT-PCR, sequencing and phylogenetic analyses of CHIKV isolates from the 2009 to 2010 epidemics in the States of Tamil Nadu and Andhra Pradesh placed them in a separate clade within the ECSA lineage. The isolates of the study had 226A in the E1 glycoprotein. The isolates had a novel E1-K211E mutation that was under significant positive selection. E1-211E is highly conserved in the Asian genotype of the virus circulated by Aedes aegypti. Unique mutations in E2 glycoprotein were identified. The two sub-lineages of ECSA genotype circulating in India parallel the abundance of Ae. albopictus and Ae. aegypti. Novel mutations in the envelope glycoproteins suggest adaptive evolution of the virus to local vector abundance. Cross neutralization of the virus isolates from recurring Indian epidemics indicated that no distinct serotypes had evolved. The study has provided insights into the origin, distribution and evolutionary adaptation of the virus to local vector abundance in the region that has reportedly, the highest incidence of CHIKV infection in the world.

  13. Reverse transcription polymerase chain reaction (RT-PCR based detection and serotyping of FMD Virus from field samples of Gazipur, Bangladesh, and adaptation of the virus in BHK-21 cell

    Directory of Open Access Journals (Sweden)

    Mohammad Ashraful Alam

    2015-09-01

    Full Text Available The study aimed for the detection and serotyping of Foot and Mouth Disease virus (FMDV circulating in Kapasia Upazila, Gazipur district of Bangladesh during 2013. Twelve samples comprising of tongue epithelium (n=8 and inter digital tissue (n=4 were collected from suspected cattle, and inocula were prepared. The inocula were inoculated into confluent BHK-21 cell line for virus propagation. After 3 subsequent passages; progressive cytopathic effects (CPE specific for FMDV i.e., rounding and flattening of cells, breaking down of the intercellular bridge and finally cell death (almost 100% were observed; these were indicative of successful virus propagation in the cells. Viral RNA was extracted, and Reverse Transcription Polymerase Chain Reaction (RT-PCR was performed using three sets of primers corresponding to the serotype and lsquo;O', and lsquo;Asia-1' and and lsquo;A', respectively. Out of the 12 samples, 10 (83.33% were found to be positive for FMDV, and all of those were of serotype and lsquo;O'. It is concluded that FMDV serotype and lsquo;O' is circulating among the cattle of Gazipur district, Bangladesh. [J Adv Vet Anim Res 2015; 2(3.000: 291-295

  14. Vitamin Supplementation at the Time of Immunization with a Cold-Adapted Influenza Virus Vaccine Corrects Poor Mucosal Antibody Responses in Mice Deficient for Vitamins A and D.

    Science.gov (United States)

    Surman, S L; Penkert, R R; Jones, B G; Sealy, R E; Hurwitz, J L

    2016-01-06

    Vitamin A and D deficiencies and insufficiencies are prevalent worldwide in developed and developing countries. Vitamin metabolites are functionally intertwined in that they are high-affinity ligands for related receptors of the nuclear receptor superfamily. The effects of vitamin A deficiencies (VAD) on antibody responses to respiratory virus vaccines have already been demonstrated. Of particular concern was the reduction in IgA, a first line of defense against pathogens in the respiratory tract. Here, we describe the individual and combined effects of vitamin A and D deficiencies in mice immunized with an attenuated influenza virus vaccine. Relative to VAD, vitamin D deficiency (VDD) had a limited effect, but double deficiencies for vitamins A and D (VAD+VDD) further reduced antibody responses in the respiratory tract. The administration of supplemental vitamins A and D to VAD+VDD mice at the time of vaccination restored responses in a dose-dependent manner. Results suggest that vitamin supplementation programs may be beneficial in a clinical setting to promote healthy immune responses to respiratory virus vaccines in vitamin-deficient individuals.

  15. Experimental infection of pregnant sows with African swine fever (ASFV Georgia 2007): Clinical outcome, pathogenesis and vertical transmission

    DEFF Research Database (Denmark)

    Lohse, Louise; Strandbygaard, Bertel; Nielsen, Jens;

    African swine fever virus (ASFV) causes a severe hemorrhagic fever in domestic pigs. The disease was introduced from the African continent to Georgia in 2007 and has since spread throughout the Caucasus and the Russian Federation. ASF is now established in Eastern Europe and outbreaks have occurred...

  16. African American Diaspora

    Directory of Open Access Journals (Sweden)

    Angela Brown

    2013-07-01

    Full Text Available The migration of blacks in North America through slavery became united.  The population of blacks past downs a tradition of artist through art to native born citizens. The art tradition involved telling stories to each generation in black families. The black culture elevated by tradition created hope to determine their personal freedom to escape from poverty of enslavement and to establish a way of life through tradition. A way of personal freedoms was through getting a good education that lead to a better foundation and a better way of life. With regard to all historic migrations (forced and voluntary, the African Union defined the African diaspora as "[consisting] of people of African origin living outside the continent, irrespective of their citizenship and nationality and who are willing to contribute to the development of the continent and the building of the African Union." Its constitutive act declares that it shall "invite and encourage the full participation of the African diaspora as an important part of our continent, in the building of the African Union." Keywords: literature concepts, African American abstracts

  17. Faith-Based Mental Health Interventions with African Americans: A Review

    Science.gov (United States)

    Hays, Krystal; Aranda, Maria P.

    2016-01-01

    Faith-based interventions have emerged culturally sensitive way to address mental health issues among African Americans. This systematic review explores the scope and efficacy of faith-based mental health intervention outcomes among African Americans. Extracted data included the study population, setting, study design, intervention, adaptations,…

  18. A Library of Infectious Hepatitis C Viruses with Engineered Mutations in the E2 Gene Reveals Growth-Adaptive Mutations That Modulate Interactions with Scavenger Receptor Class B Type I.

    Science.gov (United States)

    Zuiani, Adam; Chen, Kevin; Schwarz, Megan C; White, James P; Luca, Vincent C; Fremont, Daved H; Wang, David; Evans, Matthew J; Diamond, Michael S

    2016-12-01

    While natural hepatitis C virus (HCV) infection results in highly diverse quasispecies of related viruses over time, mutations accumulate more slowly in tissue culture, in part because of the inefficiency of replication in cells. To create a highly diverse population of HCV particles in cell culture and identify novel growth-enhancing mutations, we engineered a library of infectious HCV with all codons represented at most positions in the ectodomain of the E2 gene. We identified many putative growth-adaptive mutations and selected nine highly represented E2 mutants for further study: Q412R, T416R, S449P, T563V, A579R, L619T, V626S, K632T, and L644I. We evaluated these mutants for changes in particle-to-infectious-unit ratio, sensitivity to neutralizing antibody or CD81 large extracellular loop (CD81-LEL) inhibition, entry factor usage, and buoyant density profiles. Q412R, T416R, S449P, T563V, and L619T were neutralized more efficiently by anti-E2 antibodies and T416R, T563V, and L619T by CD81-LEL. Remarkably, all nine variants showed reduced dependence on scavenger receptor class B type I (SR-BI) for infection. This shift from SR-BI usage did not correlate with a change in the buoyant density profiles of the variants, suggesting an altered E2-SR-BI interaction rather than changes in the virus-associated lipoprotein-E2 interaction. Our results demonstrate that residues influencing SR-BI usage are distributed across E2 and support the development of large-scale mutagenesis studies to identify viral variants with unique functional properties.

  19. African Otter Workshop

    Directory of Open Access Journals (Sweden)

    Jan Reed-Smith

    2016-04-01

    Full Text Available All concerned thought this was an excellent workshop with important progress made towards creating a viable beginning of an African Otter Network. There is a long road ahead but the 2015 African Otter Workshop is a start on developing range country partners, activists and researchers as well as collaborating on issue identification and resolution which will assist in preserving at least some refugia for Africa’s otters. A list of actions was agreed on, including the creation of an African Otter Network website and social media network, apublic Otter Awareness facebook page, encouraging online reporting of otter sightings, conducting otter awareness surveys, and emphasising the need for communication with the public, other members of the network and other professionals. information not shared or documented is information LOST. A Second African Otter Workshop should be held in 2017 elsewhere in Africa to encourage attendance from a wider range of countries.

  20. African Americans and Glaucoma

    Science.gov (United States)

    ... Us Donate In This Section African Americans and Glaucoma email Send this article to a friend by ... and eventually, in developing more effective treatments. Does glaucoma treatment differ? Although treatment varies for all individuals, ...

  1. Bat flight and zoonotic viruses

    Science.gov (United States)

    O'Shea, Thomas; Cryan, Paul M.; Cunningham, Andrew A.; Fooks, Anthony R.; Hayman, David T.S.; Luis, Angela D.; Peel, Alison J.; Plowright, Raina K.; Wood, James L.N.

    2014-01-01

    Bats are sources of high viral diversity and high-profile zoonotic viruses worldwide. Although apparently not pathogenic in their reservoir hosts, some viruses from bats severely affect other mammals, including humans. Examples include severe acute respiratory syndrome coronaviruses, Ebola and Marburg viruses, and Nipah and Hendra viruses. Factors underlying high viral diversity in bats are the subject of speculation. We hypothesize that flight, a factor common to all bats but to no other mammals, provides an intensive selective force for coexistence with viral parasites through a daily cycle that elevates metabolism and body temperature analogous to the febrile response in other mammals. On an evolutionary scale, this host–virus interaction might have resulted in the large diversity of zoonotic viruses in bats, possibly through bat viruses adapting to be more tolerant of the fever response and less virulent to their natural hosts.

  2. Africans and the myth of rural retirement in South Africa, ca 1900-1950.

    Science.gov (United States)

    MacKinnon, Aran S

    2008-06-01

    The South African mining industry relied upon a massive African migrant workforce from the rural areas. Rural transformations in this migrant labor system form an important part of the story of developing capitalism in industrializing South Africa. Yet, recent historical studies on southern African migrant and rural wage labor have paid little attention to life adjustments made by the elderly and those 'burned out' by the mines and forced to leave formal wage employment in the urban areas. The South African segregationist state's rhetoric implied that 'retired' Africans could find economic security in their designated rural reserves. Indeed, legislation sought to prohibit Africans who were not employed from remaining in the 'white' urban areas. By the 1930s, however, the reserves were rapidly deteriorating. Many elderly Africans could not retire and were forced to seek wage labor. This raises significant questions about how retirement came to be defined and experienced by Africans in South Africa during a critical period of dramatic economic decline in the 1930s and 40s, and what the underlying material circumstances of African South Africans were with regard to adaptations to employment and ageing-related life changes. In many cases, elderly Africans were forced to forgo retirement, and find wage labor, usually in the most poorly paid, least sought-after or dangerous fields of employment. This article thus seeks to illuminate critical generational dimensions of the impact of segregation and racism in South Africa prior to the formal articulation of Apartheid.

  3. Toward a Caribbean psychology: an African-centered approach.

    Science.gov (United States)

    Sutherland, Marcia Elizabeth

    2011-01-01

    Although the Americas and Caribbean region are purported to comprise different ethnic groups, this article’s focus is on people of African descent, who represent the largest ethnic group in many countries. The emphasis on people of African descent is related to their family structure, ethnic identity, cultural, psychohistorical, and contemporary psychosocial realities. This article discusses the limitations of Western psychology for theory, research, and applied work on people of African descent in the Americas and Caribbean region. In view of the adaptations that some people of African descent have made to slavery, colonialism, and more contemporary forms of cultural intrusions, it is argued that when necessary, notwithstanding Western psychology’s limitations, Caribbean psychologists should reconstruct mainstream psychology to address the psychological needs of these Caribbean people. The relationship between theory and psychological interventions for the optimal development of people of African descent is emphasized throughout this article. In this regard, the African-centered and constructionist viewpoint is argued to be of utility in addressing the psychological growth and development of people of African descent living in the Americas and Caribbean region.

  4. Assessing Stigma among African Americans Living with HIV

    Science.gov (United States)

    Rao, Deepa; Molina, Yamile; Lambert, Nina; Cohn, Susan E.

    2016-01-01

    Purpose In the present study, we validated a culturally adapted stigma scale designed to assess stigma among African Americans living with HIV. Methods We collected data on the scale using an audio computer assisted self-interview (ACASI) format. We validated the scale with a sample of 62 African American participants living with HIV. Results Findings demonstrated that stigma can be measured succinctly and effectively in a 14-item scale with two subscales measuring enacted and internalized stigma. Discussion We identified many advantages to using the scale, which demonstrated good psychometric properties when used with an audio computer assisted self-interview format and with an African American sample. We recommend this scale’s use in both clinical practice and research study of HIV-stigma reduction interventions with African American populations.

  5. Early IFN-gamma production after YF 17D vaccine virus immunization in mice and its association with adaptive immune responses.

    Directory of Open Access Journals (Sweden)

    Patrícia C C Neves

    Full Text Available Yellow Fever vaccine is one of the most efficacious human vaccines ever made. The vaccine (YF 17D virus induces polyvalent immune responses, with a mixed TH1/TH2 CD4(+ cell profile, which results in robust T CD8(+ responses and high titers of neutralizing antibody. In recent years, it has been suggested that early events after yellow fever vaccination are crucial to the development of adequate acquired immunity. We have previously shown that primary immunization of humans and monkeys with YF 17D virus vaccine resulted in the early synthesis of IFN-γ. Herein we have demonstrated, for the first time that early IFN-γ production after yellow fever vaccination is a feature also of murine infection and is much more pronounced in the C57BL/6 strain compared to the BALB/c strain. Likewise, in C57BL/6 strain, we have observed the highest CD8(+ T cells responses as well as higher titers of neutralizing antibodies and total anti-YF IgG. Regardless of this intense IFN-γ response in mice, it was not possible to see higher titers of IgG2a in relation to IgG1 in both mice lineages. However, IgG2a titers were positively correlated to neutralizing antibodies levels, pointing to an important role of IFN-γ in eliciting high quality responses against YF 17D, therefore influencing the immunogenicity of this vaccine.

  6. Molecular Characterization of Chikungunya Virus, Philippines, 2011-2013.

    Science.gov (United States)

    Sy, Ava Kristy; Saito-Obata, Mariko; Medado, Inez Andrea; Tohma, Kentaro; Dapat, Clyde; Segubre-Mercado, Edelwisa; Tandoc, Amado; Lupisan, Socorro; Oshitani, Hitoshi

    2016-05-01

    During 2011-2013, a nationwide outbreak of chikungunya virus infection occurred in the Philippines. The Asian genotype was identified as the predominant genotype; sporadic cases of the East/Central/South African genotype were detected in Mindanao. Further monitoring is needed to define the transmission pattern of this virus in the Philippines.

  7. Complete Genome Sequences of Five Zika Virus Isolates.

    Science.gov (United States)

    Ladner, Jason T; Wiley, Michael R; Prieto, Karla; Yasuda, Chadwick Y; Nagle, Elyse; Kasper, Matthew R; Reyes, Daniel; Vasilakis, Nikolaos; Heang, Vireak; Weaver, Scott C; Haddow, Andrew; Tesh, Robert B; Sovann, Ly; Palacios, Gustavo

    2016-05-12

    Zika virus is an emerging human pathogen of great concern due to putative links to microcephaly and Guillain-Barre syndrome. Here, we report the complete genomes, including the 5' and 3' untranslated regions, of five Zika virus isolates, one from the Asian lineage and four from the African lineage.

  8. Geoconservation - a southern African and African perspective

    Science.gov (United States)

    Reimold, Wolf Uwe

    1999-10-01

    In contrast to Europe, where geoconservation is actively pursued in most countries and where two international symposia on this subject have been staged in 1991 and 1996, geoconservation in Africa has indeed a very poor record. Considering the wealth of outstanding geological sites and the importance African stratigraphy has within the global geological record, pro-active geoconservation on this continent has not featured very prominently to date. In the interest of science, education and tourism, unique and typical geosites need to be identified, catalogued, and prioritised with the aim being their protection. Most African countries do not have vibrant non-governmental organisations such as a strong geological society, which could drive projects like geoconservation, or strong support from the private sector for environmental work. Here, a case is made for the role that established National Geological Surveys, some of which are already involved with retroactive environmental geological work, could play in the forefront of pro-active geoconservation and site protection.

  9. Crosstalk between innate and adaptive immune responses to infectious bronchitis virus after vaccination and challenge of chickens varying in serum mannose-binding lectin concentrations

    DEFF Research Database (Denmark)

    Juul-Madsen, Helle R.; Norup, Liselotte R.; Jørgensen, Poul Henrik;

    2011-01-01

    Mannose-binding lectin (MBL), a C-type collectin with structural similarities to C1q, is an innate pattern-recognition molecule that is sequestered to sites of inflammation and infections. MBL selectively binds distinct chemical patterns, including carbohydrates expressed on all kinds of pathogens...... levels. These data demonstrate that MBL is involved in the regulation of the adaptive immune response to IBV....

  10. African literature to-day

    Directory of Open Access Journals (Sweden)

    P. Sulzer

    1974-03-01

    Full Text Available Being interested in African literature one seems to swim from the very beginning in a terminological maelstrom. What is African literature? Is it literature written by any African author in any language? That would mean approaching the question from a purely racial basis. It would imply the art of demonstrating that any piece of such literature could infallibly be recognised as African, a thing which, as far as I know has never been done. Or is African literature strictly bound to traditional African culture?

  11. Adaptation of a Chinese ferret badger strain of rabies virus to high-titered growth in BHK-21 cells for canine vaccine development.

    Science.gov (United States)

    Liu, Ye; Zhang, Shoufeng; Zhang, Fei; Hu, Rongliang

    2012-12-01

    Rabies virus strain JX08-45CC was derived from a Chinese isolate (JX08-45) by serial passage in the BHK-21 cell line, reaching a titer of 10(8) TCID(50)/mL. JX08-45CC produced rabies in adult mice but was nonpathogenic in dogs after intramuscular injection. A comparison of the entire genomes of JX08-45 and JX08-45CC led to the identification of 17 nucleotide substitutions, resulting in seven amino acid changes in the mature G and L proteins. The immunogenicity of β-propiolactone-inactivated JX08-45CC was similar to the immunogenicity of the live vaccine strains widely used in China. The inactivated vaccine induced antibody responses for more than 6 months and provided full protection from an intramuscular challenge in dogs. JX08-45CC has excellent potential for development as an inactivated vaccine for dogs in China.

  12. B