CRISPR-Cas9, a tool to efficiently increase the development of recombinant African swine fever viruses

Science.gov (United States)

African swine fever is a contagious and often lethal disease for domestic pigs with a significant economic impact on the swine industry. The etiological agent, African swine fever virus (ASFV), is a highly structurally complex double stranded DNA virus. No effective vaccines or antiviral treatment ...

Family Adaptability and Cohesion and High Blood Pressure among Urban African American women

Science.gov (United States)

Brittain, Kelly; Taylor, Jacquelyn Y.; Wu, Chun Yi

2010-01-01

African American women are at greater risk for complications related to high blood pressure. This study examined relationships between high blood pressure, pulse pressure, body mass index, family adaptability, family cohesion and social support among 146 Urban African American women. Significant relationships were found between family adaptability and systolic blood pressure (p = .03) and between adaptability and pulse pressure (p ≤ .01). Based on study results, practitioners should routinely assess family functioning, specifically family adaptability, in African American women who are at risk for high blood pressure or diagnosed with high blood pressure to minimize complications associated with hypertension. PMID:21076625

Linking African Researchers with Adaptation Policy Spaces | IDRC ...

International Development Research Centre (IDRC) Digital Library (Canada)

Linking African Researchers with Adaptation Policy Spaces. Poor understanding of policy processes tends to reduce the value of research results and the ability of researchers to influence policy. One of the main goals of IDRC's Climate Change Adaptation in Africa (CCAA) program is to build the capacity of researchers to ...

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.

Host adaptation and transmission of influenza A viruses in mammals

Science.gov (United States)

Schrauwen, Eefje JA; Fouchier, Ron AM

2014-01-01

A wide range of influenza A viruses of pigs and birds have infected humans in the last decade, sometimes with severe clinical consequences. Each of these so-called zoonotic infections provides an opportunity for virus adaptation to the new host. Fortunately, most of these human infections do not yield viruses with the ability of sustained human-to-human transmission. However, animal influenza viruses have acquired the ability of sustained transmission between humans to cause pandemics on rare occasions in the past, and therefore, influenza virus zoonoses continue to represent threats to public health. Numerous recent studies have shed new light on the mechanisms of adaptation and transmission of avian and swine influenza A viruses in mammals. In particular, several studies provided insights into the genetic and phenotypic traits of influenza A viruses that may determine airborne transmission. Here, we summarize recent studies on molecular determinants of virulence and adaptation of animal influenza A virus and discuss the phenotypic traits associated with airborne transmission of newly emerging influenza A viruses. Increased understanding of the determinants and mechanisms of virulence and transmission may aid in assessing the risks posed by animal influenza viruses to human health, and preparedness for such risks. PMID:26038511

Adapting South African Settlements to the Impacts of Climate Change

International Development Research Centre (IDRC) Digital Library (Canada)

Guidelines to assist with adaptation The project team will develop planning and design guidelines, known as the Green Book, ... the project team will: -review adaptation plans for South African cities with the goal of ... Institution Website.

Controlled transmission of African cassava mosaic virus (ACMV) by ...

African Journals Online (AJOL)

Jatropha curcas, a plant with great biodiesel potential is also used to reduce the population of whiteflies, Bemisia tabaci on cassava fields when planted as a hedge. We therefore, investigated the transmission of African cassava mosaic virus (ACMV) by the whitefly vector from cassava to seedlings of 10 accessions of J.

Adaptive pathways of zoonotic influenza viruses: from exposure to establishment in humans.

Science.gov (United States)

Reperant, Leslie A; Kuiken, Thijs; Osterhaus, Albert D M E

2012-06-22

Human influenza viruses have their ultimate origin in avian reservoirs and may adapt, either directly or after passage through another mammalian species, to circulate independently in the human population. Three sets of barriers must be crossed by a zoonotic influenza virus before it can become a human virus: animal-to-human transmission barriers; virus-cell interaction barriers; and human-to-human transmission barriers. Adaptive changes allowing zoonotic influenza viruses to cross these barriers have been studied extensively, generating key knowledge for improved pandemic preparedness. Most of these adaptive changes link acquired genetic alterations of the virus to specific adaptation mechanisms that can be screened for, both genetically and phenotypically, as part of zoonotic influenza virus surveillance programs. Human-to-human transmission barriers are only sporadically crossed by zoonotic influenza viruses, eventually triggering a worldwide influenza outbreak or pandemic. This is the most devastating consequence of influenza virus cross-species transmission. Progress has been made in identifying some of the determinants of influenza virus transmissibility. However, interdisciplinary research is needed to further characterize these ultimate barriers to the development of influenza pandemics, at both the level of the individual host and that of the population. Copyright © 2012 Elsevier Ltd. All rights reserved.

Viruses cancer - an overview | Buhari | African Journal of Clinical ...

African Journals Online (AJOL)

... by the immune system. The mechanism o f transformation o f a normal cell into a neoplastic cell can either be direct or indirect. Better understanding o f the role o f viruses in human cancer will have therapeutic implication as control can be instituted. African Journal of Clinical and Experimental Microbiology Vol. 7(2) 2006: ...

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.

Signatures of selection for environmental adaptation and zebu × taurine hybrid fitness in East African shorthorn zebu

Science.gov (United States)

The East African Shorthorn Zebu (EASZ) cattle are ancient hybrid between Asian zebu × African taurine cattle preferred by local farmers due to their adaptability to the African environment. The genetic controls of these adaptabilities are not clearly understood yet. Here, we genotyped 92 EASZ sample...

Roles of African swine fever virus structural proteins in viral infection

Directory of Open Access Journals (Sweden)

Jia Ning

2017-06-01

Full Text Available African swine fever virus (ASFV is a large, double-stranded DNA virus and the sole member of the Asfarviridae family. ASFV infects domestic pigs, wild boars, warthogs, and bush pigs, as well as soft ticks (Ornithodoros erraticus, which likely act as a vector. The major target is swine monocyte-macrophage cells. The virus can cause high fever, haemorrhagic lesions, cyanosis, anorexia, and even fatalities in domestic pigs. Currently, there is no vaccine and effective disease control strategies against its spread are culling infected pigs and maintaining high biosecurity standards. African swine fever (ASF spread to Europe from Africa in the middle of the 20th century, and later also to South America and the Caribbean. Since then, ASF has spread more widely and thus is still a great challenge for swine breeding. The genome of ASFV ranges in length from about 170 to 193 kbp depending on the isolate and contains between 150 and 167 open reading frames (ORFs. The ASFV genome encodes 150 to 200 proteins, around 50 of them structural. The roles of virus structural proteins in viral infection have been described. These proteins, such as pp220, pp62, p72, p54, p30, and CD2v, serve as the major component of virus particles and have roles in attachment, entry, and replication. All studies on ASFV proteins lay a good foundation upon which to clarify the infection mechanism and develop vaccines and diagnosis methods. In this paper, the roles of ASFV structural proteins in viral infection are reviewed.

CRISPR-Cas9, a tool to efficiently increase the development of recombinant African swine fever viruses.

Science.gov (United States)

Borca, Manuel V; Holinka, Lauren G; Berggren, Keith A; Gladue, Douglas P

2018-02-16

African swine fever virus (ASFV) causes a highly contagious disease called African swine fever. This disease is often lethal for domestic pigs, causing extensive losses for the swine industry. ASFV is a large and complex double stranded DNA virus. Currently there is no commercially available treatment or vaccine to prevent this devastating disease. Development of recombinant ASFV for producing live-attenuated vaccines or studying the involvement of specific genes in virus virulence has relied on the relatively rare event of homologous recombination in primary swine macrophages, causing difficulty to purify the recombinant virus from the wild-type parental ASFV. Here we present the use of the CRISPR-Cas9 gene editing system as a more robust and efficient system to produce recombinant ASFVs. Using CRISPR-Cas9 a recombinant virus was efficiently developed by deleting the non-essential gene 8-DR from the genome of the highly virulent field strain Georgia07 using swine macrophages as cell substrate.

Simultaneous deletion of the 9GL and UK genes from the African swine fever virus Georgia 2007 isolate results in virus attenuation and may be a potential virus vaccine strain

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 the swine industry. The control of African Swine Fever (ASF) has been hampered by the unavailability of vaccines. Successful experi...

Adaptation of Pandemic H1N1 Influenza Viruses in Mice▿

Science.gov (United States)

Ilyushina, Natalia A.; Khalenkov, Alexey M.; Seiler, Jon P.; Forrest, Heather L.; Bovin, Nicolai V.; Marjuki, Henju; Barman, Subrata; Webster, Robert G.; Webby, Richard J.

2010-01-01

The molecular mechanism by which pandemic 2009 influenza A viruses were able to sufficiently adapt to humans is largely unknown. Subsequent human infections with novel H1N1 influenza viruses prompted an investigation of the molecular determinants of the host range and pathogenicity of pandemic influenza viruses in mammals. To address this problem, we assessed the genetic basis for increased virulence of A/CA/04/09 (H1N1) and A/TN/1-560/09 (H1N1) isolates, which are not lethal for mice, in a new mammalian host by promoting their mouse adaptation. The resulting mouse lung-adapted variants showed significantly enhanced growth characteristics in eggs, extended extrapulmonary tissue tropism, and pathogenicity in mice. All mouse-adapted viruses except A/TN/1-560/09-MA2 grew faster and to higher titers in cells than the original strains. We found that 10 amino acid changes in the ribonucleoprotein (RNP) complex (PB2 E158G/A, PA L295P, NP D101G, and NP H289Y) and hemagglutinin (HA) glycoprotein (K119N, G155E, S183P, R221K, and D222G) controlled enhanced mouse virulence of pandemic isolates. HA mutations acquired during adaptation affected viral receptor specificity by enhancing binding to α2,3 together with decreasing binding to α2,6 sialyl receptors. PB2 E158G/A and PA L295P amino acid substitutions were responsible for the significant enhancement of transcription and replication activity of the mouse-adapted H1N1 variants. Taken together, our findings suggest that changes optimizing receptor specificity and interaction of viral polymerase components with host cellular factors are the major mechanisms that contribute to the optimal competitive advantage of pandemic influenza viruses in mice. These modulators of virulence, therefore, may have been the driving components of early evolution, which paved the way for novel 2009 viruses in mammals. PMID:20592084

The effect of temperature on the in vitro transcriptase reaction of bluetongue virus, epizootic haemorrhagic disease virus and African horsesickness virus

International Nuclear Information System (INIS)

Van Dijk, A.A.; Huismans, H.

1982-01-01

Virions of bluetongue virus (BTV), epizootic haemorrhagic disease virus (EHDV) and African horsesickness virus (AHSV) can be converted to core particles by treatment with chymotrypsin and magnesium. The conversion is characterized by the removal of the 2 outer capsid polypeptides of the virion. The loss of these 2 proteins results in an increase in density from 1,36 g/ml to 1,40 g/ml on CsCl gradients. The BTV, EHDV and AHSV core particles have an associated double-stranded RNA dependent RNA transcriptase that appears to transcribe mRNA optimally at 28 degrees Celsius. It was found, at least in the case of BTV, that this low temperature preference is not an intrinsic characteristic of the transcriptase, but is due to a temperature-dependent inhibition of transcription at high core concentrations

Propagation of classical swine fever virus in vitro circumventing heparan sulfate-adaptation.

Science.gov (United States)

Eymann-Häni, Rita; Leifer, Immanuel; McCullough, Kenneth C; Summerfield, Artur; Ruggli, Nicolas

2011-09-01

Amplification of natural virus isolates in permanent cell lines can result in adaptation, in particular enhanced binding to heparan sulfate (HS)-containing glycosaminoglycans present on most vertebrate cells. This has been reported for several viruses, including the pestivirus classical swine fever virus (CSFV), the causative agent of a highly contagious hemorrhagic disease in pigs. Propagation of CSFV in cell culture is essential in virus diagnostics and research. Adaptation of CSFV to HS-binding has been related to amino acid changes in the viral E(rns) glycoprotein, resulting in viruses with altered replication characteristics in vitro and in vivo. Consequently, a compound blocking the HS-containing structures on cell surfaces was employed to monitor conversion from HS-independency to HS-dependency. It was shown that the porcine PEDSV.15 cell line permitted propagation of CSFV within a limited number of passages without adaptation to HS-binding. The selection of HS-dependent CSFV mutants was also prevented by propagation of the virus in the presence of DSTP 27. The importance of these findings can be seen from the altered ratio of cell-associated to secreted virus upon acquisition of enhanced HS-binding affinity, a phenotype proposed previously to be related to virulence in the natural host. Copyright © 2011 Elsevier B.V. All rights reserved.

Visualization of the African swine fever virus infection in living cells by incorporation into the virus particle of green fluorescent protein-p54 membrane protein chimera

International Nuclear Information System (INIS)

Hernaez, Bruno; Escribano, Jose M.; Alonso, Covadonga

2006-01-01

Many stages of African swine fever virus infection have not yet been studied in detail. To track the behavior of African swine fever virus (ASFV) in the infected cells in real time, we produced an infectious recombinant ASFV (B54GFP-2) that expresses and incorporates into the virus particle a chimera of the p54 envelope protein fused to the enhanced green fluorescent protein (EGFP). The incorporation of the fusion protein into the virus particle was confirmed immunologically and it was determined that p54-EGFP was fully functional by confirmation that the recombinant virus made normal-sized plaques and presented similar growth curves to the wild-type virus. The tagged virus was visualized as individual fluorescent particles during the first stages of infection and allowed to visualize the infection progression in living cells through the viral life cycle by confocal microscopy. In this work, diverse potential applications of B54GFP-2 to study different aspects of ASFV infection are shown. By using this recombinant virus it was possible to determine the trajectory and speed of intracellular virus movement. Additionally, we have been able to visualize for first time the ASFV factory formation dynamics and the cytophatic effect of the virus in live infected cells. Finally, we have analyzed virus progression along the infection cycle and infected cell death as time-lapse animations

Adapting hypertension self-management interventions to enhance their sustained effectiveness among urban African Americans.

Science.gov (United States)

Ameling, Jessica M; Ephraim, Patti L; Bone, Lee R; Levine, David M; Roter, Debra L; Wolff, Jennifer L; Hill-Briggs, Felicia; Fitzpatrick, Stephanie L; Noronha, Gary J; Fagan, Peter J; Lewis-Boyer, LaPricia; Hickman, Debra; Simmons, Michelle; Purnell, Leon; Fisher, Annette; Cooper, Lisa A; Aboumatar, Hanan J; Albert, Michael C; Flynn, Sarah J; Boulware, L Ebony

2014-01-01

African Americans suffer disproportionately poor hypertension control despite the availability of efficacious interventions. Using principles of community-based participatory research and implementation science, we adapted established hypertension self-management interventions to enhance interventions' cultural relevance and potential for sustained effectiveness among urban African Americans. We obtained input from patients and their family members, their health care providers, and community members. The process required substantial time and resources, and the adapted interventions will be tested in a randomized controlled trial.

Adapting Hypertension Self-Management Interventions to Enhance their Sustained Effectiveness among Urban African Americans

Science.gov (United States)

Ameling, Jessica M.; Ephraim, Patti L.; Bone, Lee R.; Levine, David M.; Roter, Debra L.; Wolff, Jennifer L.; Hill-Briggs, Felicia; Fitzpatrick, Stephanie L.; Noronha, Gary J.; Fagan, Peter J.; Lewis-Boyer, LaPricia; Hickman, Debra; Simmons, Michelle; Purnell, Leon; Fisher, Annette; Cooper, Lisa A.; Aboumatar, Hanan J.; Albert, Michael C.; Flynn, Sarah J.; Boulware, L. Ebony

2014-01-01

African Americans suffer disproportionately poor hypertension control despite the availability of efficacious interventions. Using principles of community-based participatory research and implementation science, we adapted established hypertension self-management interventions to enhance interventions’ cultural relevance and potential for sustained effectiveness among urban African Americans. We obtained input from patients and their family members, their health care providers, and community members. The process required substantial time and resources, and the adapted interventions will be tested in a randomized controlled trial. PMID:24569158

Virus Genomes Reveal the Factors that Spread and Sustained the West African Ebola Epidemic

Science.gov (United States)

2016-08-09

Ladner, J. T. et al. Evolution and Spread of Ebola Virus in Liberia , 2014--2015. Cell Host Microbe 18, 659–669 (2015). 15. Lemey, P. et al. Unifying...Virus genomes reveal the factors that spread and sustained the West African Ebola epidemic. Gytis Dudas1,2, Luiz Max Carvalho1, Trevor Bedford2...Charlesville, Liberia ., 19University of Sierra Leone, Freetown, Sierra Leone , 20Center for Systems Biology, Department of Organismic and Evolutionary

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...

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.

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...... in a plaque reduction assay were generated. To dissect the antigenic structure of AHSV VP5, the protein was cloned in Escherichia coil using the pET3 system. The immunoreactivity of both MAbs, and horse and rabbit polyclonal antisera, with 17 overlapping fragments from VP5 was analyzed. The most....... Neutralizing epitopes were defined at positions 85-92 (PDPLSPGE) for MAb 10AE12 and at 179-185 (EEDLRTR) for MAb 10AC6. Epitope 10AE12 is highly conserved between the different orbiviruses. MAb 10AE12 was able to recognize bluetongue virus VP5 and epizootic hemorrhagic disease virus VP5 by several techniques...

Approaches and Perspectives for Development of African Swine Fever Virus Vaccines

Directory of Open Access Journals (Sweden)

Marisa Arias

2017-10-01

Full Text Available African swine fever (ASF is a complex disease of swine, caused by a large DNA virus belonging to the family Asfarviridae. The disease shows variable clinical signs, with high case fatality rates, up to 100%, in the acute forms. ASF is currently present in Africa and Europe where it circulates in different scenarios causing a high socio-economic impact. In most affected regions, control has not been effective in part due to lack of a vaccine. The availability of an effective and safe ASFV vaccines would support and enforce control–eradication strategies. Therefore, work leading to the rational development of protective ASF vaccines is a high priority. Several factors have hindered vaccine development, including the complexity of the ASF virus particle and the large number of proteins encoded by its genome. Many of these virus proteins inhibit the host’s immune system thus facilitating virus replication and persistence. We review previous work aimed at understanding ASFV–host interactions, including mechanisms of protective immunity, and approaches for vaccine development. These include live attenuated vaccines, and “subunit” vaccines, based on DNA, proteins, or virus vectors. In the shorter to medium term, live attenuated vaccines are the most promising and best positioned candidates. Gaps and future research directions are evaluated.

Adapting Hypertension Self-Management Interventions to Enhance their Sustained Effectiveness among Urban African Americans

OpenAIRE

Ameling, Jessica M.; Ephraim, Patti L.; Bone, Lee R.; Levine, David M.; Roter, Debra L.; Wolff, Jennifer L.; Hill-Briggs, Felicia; Fitzpatrick, Stephanie L.; Noronha, Gary J.; Fagan, Peter J.; Lewis-Boyer, LaPricia; Hickman, Debra; Simmons, Michelle; Purnell, Leon; Fisher, Annette

2014-01-01

African Americans suffer disproportionately poor hypertension control despite the availability of efficacious interventions. Using principles of community-based participatory research and implementation science, we adapted established hypertension self-management interventions to enhance interventions’ cultural relevance and potential for sustained effectiveness among urban African Americans. We obtained input from patients and their family members, their health care providers, and community ...

Immunogenicity of plant-produced African horse sickness virus-like particles: implications for a novel vaccine.

Science.gov (United States)

Dennis, Susan J; Meyers, Ann E; Guthrie, Alan J; Hitzeroth, Inga I; Rybicki, Edward P

2018-02-01

African horse sickness (AHS) is a debilitating and often fatal viral disease affecting horses in much of Africa, caused by the dsRNA orbivirus African horse sickness virus (AHSV). Vaccination remains the single most effective weapon in combatting AHS, as there is no treatment for the disease apart from good animal husbandry. However, the only commercially available vaccine is a live-attenuated version of the virus (LAV). The threat of outbreaks of the disease outside its endemic region and the fact that the LAV is not licensed for use elsewhere in the world, have spurred attempts to develop an alternative safer, yet cost-effective recombinant vaccine. Here, we report the plant-based production of a virus-like particle (VLP) AHSV serotype five candidate vaccine by Agrobacterium tumefaciens-mediated transient expression of all four capsid proteins in Nicotiana benthamiana using the cowpea mosaic virus-based HyperTrans (CPMV-HT) and associated pEAQ plant expression vector system. The production process is fast and simple, scalable, economically viable, and most importantly, guinea pig antiserum raised against the vaccine was shown to neutralize live virus in cell-based assays. To our knowledge, this is the first report of AHSV VLPs produced in plants, which has important implications for the containment of, and fight against the spread of, this deadly disease. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Social vulnerability and Ebola virus disease in rural Liberia

Science.gov (United States)

John A. Stanturf; Scott L. Goodrick; Melvin L. Warren; Susan Charnley; Christie M. Stegall

2015-01-01

The Ebola virus disease (EVD) epidemic that has stricken thousands of people in the three West African countries of Liberia, Sierra Leone, and Guinea highlights the lack of adaptive capacity in post-conflict countries. The scarcity of health services in particular renders these populations vulnerable to multiple interacting stressors including food insecurity, climate...

Pathology of experimental Ebola virus infection in African green monkeys. Involvement of fibroblastic reticular cells.

Science.gov (United States)

Davis, K J; Anderson, A O; Geisbert, T W; Steele, K E; Geisbert, J B; Vogel, P; Connolly, B M; Huggins, J W; Jahrling, P B; Jaax, N K

1997-08-01

Ebola virus has been responsible for explosive lethal outbreaks of hemorrhagic fever in both humans and nonhuman primates. Previous studies showed a predilection of Ebola virus for cells of the mononuclear phagocyte system and endothelial cells. To examine the distribution of lesions and Ebola virus antigen in the tissues of six adult male African green monkeys (Cercopithecus aethiops) that died 6 to 7 days after intraperitoneal inoculation of Ebola-Zaire (Mayinga) virus. Tissues were examined histologically, immunohistochemically, and ultrastructurally. A major novel finding of this study was that fibroblastic reticular cells were immunohistochemically and ultrastructurally identified as targets of Ebola virus infection. The role of Ebola virus-infected fibroblastic reticular cells in the pathogenesis of Ebola hemorrhagic fever warrants further investigation. This is especially important because of recent observations indicating that fibroblastic reticular cells, along with the reticular fibers they produce, maximize the efficiency of the immune response.

Adapted Lethality: What We Can Learn from Guinea Pig-Adapted Ebola Virus Infection Model.

Science.gov (United States)

Cheresiz, S V; Semenova, E A; Chepurnov, A A

2016-01-01

Establishment of small animal models of Ebola virus (EBOV) infection is important both for the study of genetic determinants involved in the complex pathology of EBOV disease and for the preliminary screening of antivirals, production of therapeutic heterologic immunoglobulins, and experimental vaccine development. Since the wild-type EBOV is avirulent in rodents, the adaptation series of passages in these animals are required for the virulence/lethality to emerge in these models. Here, we provide an overview of our several adaptation series in guinea pigs, which resulted in the establishment of guinea pig-adapted EBOV (GPA-EBOV) variants different in their characteristics, while uniformly lethal for the infected animals, and compare the virologic, genetic, pathomorphologic, and immunologic findings with those obtained in the adaptation experiments of the other research groups.

Adapted Lethality: What We Can Learn from Guinea Pig-Adapted Ebola Virus Infection Model

Directory of Open Access Journals (Sweden)

S. V. Cheresiz

2016-01-01

Full Text Available Establishment of small animal models of Ebola virus (EBOV infection is important both for the study of genetic determinants involved in the complex pathology of EBOV disease and for the preliminary screening of antivirals, production of therapeutic heterologic immunoglobulins, and experimental vaccine development. Since the wild-type EBOV is avirulent in rodents, the adaptation series of passages in these animals are required for the virulence/lethality to emerge in these models. Here, we provide an overview of our several adaptation series in guinea pigs, which resulted in the establishment of guinea pig-adapted EBOV (GPA-EBOV variants different in their characteristics, while uniformly lethal for the infected animals, and compare the virologic, genetic, pathomorphologic, and immunologic findings with those obtained in the adaptation experiments of the other research groups.

African and Asian Zika virus isolates display phenotypic differences both in vitro and in vivo

Science.gov (United States)

Zika virus (ZIKV) is a mosquito-borne flavivirus that has emerged since 2007 to cause outbreaks in Africa, Asia, Oceania, and most recently in the Americas. Here we utilized isolate history, as well as genetic and phylogenetic analyses to characterize three low-passage isolates representing African ...

The first phlebo-like virus infecting plants: a case study on the adaptation of negative-stranded RNA viruses to new hosts.

Science.gov (United States)

Navarro, Beatriz; Minutolo, Maria; De Stradis, Angelo; Palmisano, Francesco; Alioto, Daniela; Di Serio, Francesco

2018-05-01

A novel negative-stranded (ns) RNA virus associated with a severe citrus disease reported more than 80 years ago has been identified. Transmission electron microscopy showed that this novel virus, tentatively named citrus concave gum-associated virus, is flexuous and non-enveloped. Notwithstanding, its two genomic RNAs share structural features with members of the genus Phlebovirus, which are enveloped arthropod-transmitted viruses infecting mammals, and with a group of still unclassified phlebo-like viruses mainly infecting arthropods. CCGaV genomic RNAs code for an RNA-dependent RNA polymerase, a nucleocapsid protein and a putative movement protein showing structural and phylogenetic relationships with phlebo-like viruses, phleboviruses and the unrelated ophioviruses, respectively, thus providing intriguing evidence of a modular genome evolution. Phylogenetic reconstructions identified an invertebrate-restricted virus as the most likely ancestor of this virus, revealing that its adaptation to plants was independent from and possibly predated that of the other nsRNA plant viruses. These data are consistent with an evolutionary scenario in which trans-kingdom adaptation occurred several times during the history of nsRNA viruses and followed different evolutionary pathways, in which genomic RNA segments were gained or lost. The need to create a new genus for this bipartite nsRNA virus and the impact of the rapid and specific detection methods developed here on citrus sanitation and certification are also discussed. © 2017 BSPP AND JOHN WILEY & SONS LTD.

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

2015-12-09

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. Copyright © 2015 Elsevier Inc. All rights reserved.

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

Directory of Open Access Journals (Sweden)

Yasuha Arai

2016-04-01

Full Text Available 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.

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......Classical swine fever virus (CSFV) causes an economically important disease of swine. Four different viruses were rescued from full-length cloned cDNAs derived from the Paderborn strain of CSFV. Three of these viruses had been modified by mutagenesis (with 7 or 8 nt changes) within stem 2...... each of four independent virus populations were observed that restored the coding sequence to that of the parental field strain. These adaptations occurred with different kinetics. The combination of reverse genetics and in depth, full genome sequencing provides a powerful approach to analyse virus...

A culturally adapted family intervention for African American families coping with parental cancer: outcomes of a pilot study.

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

2013-07-01

The primary objective of this 2-year pilot study was to evaluate the effectiveness of a culturally adapted family intervention in improving family communication among African American parents coping with cancer and their school-age children. A secondary objective was to determine its impact on other symptoms of psychosocial distress (depression and anxiety). The third objective was to assess for acceptability and feasibility. Using a two-arm pre-intervention and post-intervention prospective design, 12 African American families received five bi-monthly sessions of either a culturally adapted family intervention (n=7 families) or psycho-education treatment (n=5 families). Parents and their children completed pre-intervention and post-intervention questionnaires assessing perceptions of family communication, quality of their relationship, and symptoms of depression. School-age children additionally completed a questionnaire assessing their levels of anxiety. Consumer satisfaction was also evaluated at post-intervention. Parents and school-age children who completed the culturally adapted family intervention reported significantly better communication with each other and were more satisfied compared with the psycho-education control group. No changes were noted in symptoms of anxiety or depression. The culturally adapted family intervention was acceptable based on our findings, families' feedback, and rates of retention. Feasibility is uncertain because our oncology clinic approach to recruitment was slower than expected. Providing culturally adapted family intervention programs to African American families who are coping with parental cancer may result in improved family communication. This pilot study serves as the first step in the development of culturally adapted family intervention programs to help African American families cope with parental cancer. Copyright © 2012 John Wiley & Sons, Ltd.

Virus-Bacterium Interactions in Water and Sediment of West African Inland Aquatic Systems

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Bettarel, Yvan; Bouvy, Marc; Dumont, Claire; Sime-Ngando, Télesphore

2006-01-01

The ecology of virioplankton in tropical aquatic ecosystems is poorly documented, and in particular, there are no references concerning African continental waters in the literature. In this study, we examined virus-bacterium interactions in the pelagic and benthic zones of seven contrasting shallow inland waters in Senegal, including one hypersaline lake. SYBR Gold-stained samples revealed that in the surface layers of the sites, the numbers of viruses were in the same range as the numbers of viruses reported previously for productive temperate systems. Despite high bacterial production rates, the percentages of visibly infected cells (as determined by transmission electron microscopy) were similar to the lowest percentages (range, 0.3 to 1.1%; mean, 0.5%) found previously at pelagic freshwater or marine sites, presumably because of the local environmental and climatic conditions. Since the percentages of lysogenic bacteria were consistently less than 8% for pelagic and benthic samples, lysogeny did not appear to be a dominant strategy for virus propagation at these sites. In the benthic samples, viruses were highly concentrated, but paradoxically, no bacteria were visibly infected. This suggests that sediment provides good conditions for virus preservation but ironically is an unfavorable environment for proliferation. In addition, given the comparable size distributions of viruses in the water and sediment samples, our results support the paradigm that aquatic viruses are ubiquitous and may have moved between the two compartments of the shallow systems examined. Overall, this study provides additional information about the relevance of viruses in tropical areas and indicates that the intensity of virus-bacterium interactions in benthic habitats may lower than the intensity in the adjacent bodies of water. PMID:16885276

Evolution and spread of Ebola virus in Liberia, 2014–2015

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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

2015-01-01

SUMMARY 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. PMID:26651942

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

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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.

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.

Chikungunya virus adapts to tiger mosquito via evolutionary convergence: a sign of things to come?

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Higgs Stephen

2008-02-01

Full Text Available Abstract Since 2004, several million indigenous cases of Chikungunya virus disease occurred in Africa, the Indian Ocean, India, Asia and, recently, Europe. The virus, usually transmitted by Aedes aegypti mosquitoes, has now repeatedly been associated with a new vector, Ae. Albopictus. Analysis of full-length viral sequences reveals three independent events of virus exposure to Ae. Albopictus, each followed by the acquisition of a single adaptive mutation providing selective advantage for transmission by this mosquito. This disconcerting and current unique example of "evolutionary convergence" occurring in nature illustrates rapid pathogen adaptation to ecological perturbation, driven directly as a consequence of human activities.

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

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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.

Selective Bottlenecks Shape Evolutionary Pathways Taken during Mammalian Adaptation of a 1918-like Avian Influenza Virus.

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Moncla, Louise H; Zhong, Gongxun; Nelson, Chase W; Dinis, Jorge M; Mutschler, James; Hughes, Austin L; Watanabe, Tokiko; Kawaoka, Yoshihiro; Friedrich, Thomas C

2016-02-10

Avian influenza virus reassortants resembling the 1918 human pandemic virus can become transmissible among mammals by acquiring mutations in hemagglutinin (HA) and polymerase. Using the ferret model, we trace the evolutionary pathway by which an avian-like virus evolves the capacity for mammalian replication and airborne transmission. During initial infection, within-host HA diversity increased drastically. Then, airborne transmission fixed two polymerase mutations that do not confer a detectable replication advantage. In later transmissions, selection fixed advantageous HA1 variants. Transmission initially involved a "loose" bottleneck, which became strongly selective after additional HA mutations emerged. The stringency and evolutionary forces governing between-host bottlenecks may therefore change throughout host adaptation. Mutations occurred in multiple combinations in transmitted viruses, suggesting that mammalian transmissibility can evolve through multiple genetic pathways despite phenotypic constraints. Our data provide a glimpse into avian influenza virus adaptation in mammals, with broad implications for surveillance on potentially zoonotic viruses. Copyright © 2016 Elsevier Inc. All rights reserved.

Utilizing community-based participatory research to adapt a mental health intervention for African American emerging adults.

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Mance, Gishawn A; Mendelson, Tamar; Byrd, Benjamin; Jones, Jahon; Tandon, Darius

2010-01-01

Adapting mental health interventions to heighten their cultural and contextual appropriateness may be critical for engaging ethnic/racial groups that have been traditionally excluded or marginalized. Community-based participatory research (CBPR) is a collaborative research approach that highlights unique strengths and expertise of those involved. Although intervention adaptations have garnered much attention there is little previous work specifically describing the adaptation process of mental health interventions using CBPR. This article summarizes the use of a CBPR approach to adapt a mental health intervention for urban adolescents and young adults disconnected from school and work, a population at elevated risk for poor mental health owing to the presence of numerous chronic stressors. We describe the process undertaken to modify the content and delivery format of an evidence-based intervention. Unique challenges of working with urban African American adolescents and young adults in a job training program are highlighted. By incorporating principles of co-learning and shared responsibility, this partnership was able to achieve positive outcomes. Our experience suggests that a CBPR approach can be used effectively to adapt a mental health intervention in collaboration with African American adolescents and emerging adults in a job training program.

Attenuated Human Parainfluenza Virus Type 1 Expressing Ebola Virus Glycoprotein GP Administered Intranasally Is Immunogenic in African Green Monkeys.

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Lingemann, Matthias; Liu, Xueqiao; Surman, Sonja; Liang, Bo; Herbert, Richard; Hackenberg, Ashley D; Buchholz, Ursula J; Collins, Peter L; Munir, Shirin

2017-05-15

The recent 2014-2016 Ebola virus (EBOV) outbreak prompted increased efforts to develop vaccines against EBOV disease. We describe the development and preclinical evaluation of an attenuated recombinant human parainfluenza virus type 1 (rHPIV1) expressing the membrane-anchored form of EBOV glycoprotein GP, as an intranasal (i.n.) EBOV vaccine. GP was codon optimized and expressed either as a full-length protein or as an engineered chimeric form in which its transmembrane and cytoplasmic tail (TMCT) domains were replaced with those of the HPIV1 F protein in an effort to enhance packaging into the vector particle and immunogenicity. GP was inserted either preceding the N gene (pre-N) or between the N and P genes (N-P) of rHPIV1 bearing a stabilized attenuating mutation in the P/C gene (C Δ170 ). The constructs grew to high titers and efficiently and stably expressed GP. Viruses were attenuated, replicating at low titers over several days, in the respiratory tract of African green monkeys (AGMs). Two doses of candidates expressing GP from the pre-N position elicited higher GP neutralizing serum antibody titers than the N-P viruses, and unmodified GP induced higher levels than its TMCT counterpart. Unmodified EBOV GP was packaged into the HPIV1 particle, and the TMCT modification did not increase packaging or immunogenicity but rather reduced the stability of GP expression during in vivo replication. In conclusion, we identified an attenuated and immunogenic i.n. vaccine candidate expressing GP from the pre-N position. It is expected to be well tolerated in humans and is available for clinical evaluation. IMPORTANCE EBOV hemorrhagic fever is one of the most lethal viral infections and lacks a licensed vaccine. Contact of fluids from infected individuals, including droplets or aerosols, with mucosal surfaces is an important route of EBOV spread during a natural outbreak, and aerosols also might be exploited for intentional virus spread. Therefore, vaccines that protect

Assessing the impact of climate change on vector-borne viruses in the EU through the elicitation of expert opinion.

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Gale, P; Brouwer, A; Ramnial, V; Kelly, L; Kosmider, R; Fooks, A R; Snary, E L

2010-02-01

Expert opinion was elicited to undertake a qualitative risk assessment to estimate the current and future risks to the European Union (EU) from five vector-borne viruses listed by the World Organization for Animal Health. It was predicted that climate change will increase the risk of incursions of African horse sickness virus (AHSV), Crimean-Congo haemorrhagic fever virus (CCHFV) and Rift Valley fever virus (RVFV) into the EU from other parts of the world, with African swine fever virus (ASFV) and West Nile virus (WNV) being less affected. Currently the predicted risks of incursion were lowest for RVFV and highest for ASFV. Risks of incursion were considered for six routes of entry (namely vectors, livestock, meat products, wildlife, pets and people). Climate change was predicted to increase the risk of incursion from entry of vectors for all five viruses to some degree, the strongest effects being predicted for AHSV, CCHFV and WNV. This work will facilitate identification of appropriate risk management options in relation to adaptations to climate change.

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

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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.

Identification of a new genotype of African swine fever Virus in domestic pigs from Ethiopia

International Nuclear Information System (INIS)

Achenbach, J.E.; Gallardo, C.; Nieto-Pelegrín, E.; Rivera-Arroyo, B.; Degefa-Negi, T.; Arias, M.; Jenberie, S.; Mulisa, D.D.; Gizaw, D.; Gelaye, E.; Chibssa, T.R.; Belaye, A.; Loitsch, A.; Forsa, M.; Yami, M.; Diallo, A.; Soler, A.; Lamien, C.E.

2016-01-01

Full text: African swine fever (ASF) is an important emerging transboundary animal disease (TAD), which currently has an impact on many countries in Africa, Eastern Europe, the Caucasus and the Russian Federation. The current situation in Europe shows the ability of the virus to rapidly spread, which stands to threaten the global swine industry. At present, there is no viable vaccine to minimize spread of the disease and stamping out is the main source of control. In February 2011, Ethiopia had reported its first suspected outbreaks of ASF. Genomic analyses of the collected ASF virus (ASFV) strains were undertaken using 23 tissue samples collected from domestic swine in Ethiopia from 2011 to 2014. The analysis of Ethiopian ASFVs partial p72 gene sequence showed the identification of a new genotype, genotype XXIII that shares a common ancestor with genotypes IX and X, which comprise isolates circulating in Eastern African countries and the Republic of Congo. Analysis of the p54 gene also followed the p72 pattern and the deduced amino acid sequence of the central variable region (CVR) of the B602L gene showed novel tetramer repeats not previously characterized. (author)

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

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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...

Immunization of Pigs by DNA Prime and Recombinant Vaccinia Virus Boost To Identify and Rank African Swine Fever Virus Immunogenic and Protective Proteins.

Science.gov (United States)

Jancovich, James K; Chapman, Dave; Hansen, Debra T; Robida, Mark D; Loskutov, Andrey; Craciunescu, Felicia; Borovkov, Alex; Kibler, Karen; Goatley, Lynnette; King, Katherine; Netherton, Christopher L; Taylor, Geraldine; Jacobs, Bertram; Sykes, Kathryn; Dixon, Linda K

2018-04-15

African swine fever virus (ASFV) causes an acute hemorrhagic fever in domestic pigs, with high socioeconomic impact. No vaccine is available, limiting options for control. Although live attenuated ASFV can induce up to 100% protection against lethal challenge, little is known of the antigens which induce this protective response. To identify additional ASFV immunogenic and potentially protective antigens, we cloned 47 viral genes in individual plasmids for gene vaccination and in recombinant vaccinia viruses. These antigens were selected to include proteins with different functions and timing of expression. Pools of up to 22 antigens were delivered by DNA prime and recombinant vaccinia virus boost to groups of pigs. Responses of immune lymphocytes from pigs to individual recombinant proteins and to ASFV were measured by interferon gamma enzyme-linked immunosorbent spot (ELISpot) assays to identify a subset of the antigens that consistently induced the highest responses. All 47 antigens were then delivered to pigs by DNA prime and recombinant vaccinia virus boost, and pigs were challenged with a lethal dose of ASFV isolate Georgia 2007/1. Although pigs developed clinical and pathological signs consistent with acute ASFV, viral genome levels were significantly reduced in blood and several lymph tissues in those pigs immunized with vectors expressing ASFV antigens compared with the levels in control pigs. IMPORTANCE The lack of a vaccine limits the options to control African swine fever. Advances have been made in the development of genetically modified live attenuated ASFV that can induce protection against challenge. However, there may be safety issues relating to the use of these in the field. There is little information about ASFV antigens that can induce a protective immune response against challenge. We carried out a large screen of 30% of ASFV antigens by delivering individual genes in different pools to pigs by DNA immunization prime and recombinant vaccinia

Human Adaptation of Ebola Virus during the West African Outbreak.

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Urbanowicz, Richard A; McClure, C Patrick; Sakuntabhai, Anavaj; Sall, Amadou A; Kobinger, Gary; Müller, Marcel A; Holmes, Edward C; Rey, Félix A; Simon-Loriere, Etienne; Ball, Jonathan K

2016-11-03

The 2013-2016 outbreak of Ebola virus (EBOV) in West Africa was the largest recorded. It began following the cross-species transmission of EBOV from an animal reservoir, most likely bats, into humans, with phylogenetic analysis revealing the co-circulation of several viral lineages. We hypothesized that this prolonged human circulation led to genomic changes that increased viral transmissibility in humans. We generated a synthetic glycoprotein (GP) construct based on the earliest reported isolate and introduced amino acid substitutions that defined viral lineages. Mutant GPs were used to generate a panel of pseudoviruses, which were used to infect different human and bat cell lines. These data revealed that specific amino acid substitutions in the EBOV GP have increased tropism for human cells, while reducing tropism for bat cells. Such increased infectivity may have enhanced the ability of EBOV to transmit among humans and contributed to the wide geographic distribution of some viral lineages. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

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

2009-08-01

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

Amino Acid Substitutions Associated with Avian H5N6 Influenza A Virus Adaptation to Mice

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Chunmao Zhang

2017-09-01

Full Text Available At least 15 cases of human beings infected with H5N6 have been reported since 2014, of which at least nine were fatal. The highly pathogenic avian H5N6 influenza virus may pose a serious threat to both public health and the poultry industry. However, the molecular features promoting the adaptation of avian H5N6 influenza viruses to mammalian hosts is not well understood. Here, we sequentially passaged an avian H5N6 influenza A virus (A/Northern Shoveler/Ningxia/488-53/2015 10 times in mice to identify the adaptive amino acid substitutions that confer enhanced virulence to H5N6 in mammals. The 1st and 10th passages of the mouse-adapted H5N6 viruses were named P1 and P10, respectively. P1 and P10 displayed higher pathogenicity in mice than their parent strain. P10 showed significantly higher replication capability in vivo and could be detected in the brains of mice, whereas P1 displayed higher replication efficiency in their lungs but was not detectable in the brain. Similar to its parent strain, P10 remained no transmissible between guinea pigs. Using genome sequencing and alignment, multiple amino acid substitutions, including PB2 E627K, PB2 T23I, PA T97I, and HA R239H, were found in the adaptation of H5N6 to mice. In summary, we identified amino acid changes that are associated with H5N6 adaptation to mice.

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...

Adaptive evolution during the establishment of European avian-like H1N1 influenza A virus in swine.

Science.gov (United States)

Joseph, Udayan; Vijaykrishna, Dhanasekaran; Smith, Gavin J D; Su, Yvonne C F

2018-04-01

An H1N1 subtype influenza A virus with all eight gene segments derived from wild birds (including mallards), ducks and chickens, caused severe disease outbreaks in swine populations in Europe beginning in 1979 and successfully adapted to form the European avian-like swine (EA-swine) influenza lineage. Genes of the EA-swine lineage that are clearly segregated from its closest avian relatives continue to circulate in swine populations globally and represent a unique opportunity to study the adaptive process of an avian-to-mammalian cross-species transmission. Here, we used a relaxed molecular clock model to test whether the EA-swine virus originated through the introduction of a single avian ancestor as an entire genome, followed by an analysis of host-specific selection pressures among different gene segments. Our data indicated independent introduction of gene segments via transmission of avian viruses into swine followed by reassortment events that occurred at least 1-4 years prior to the EA-swine outbreak. All EA-swine gene segments exhibit greater selection pressure than avian viruses, reflecting both adaptive pressures and relaxed selective constraints that are associated with host switching. Notably, we identified key amino acid mutations in the viral surface proteins (H1 and N1) that play a role in adaptation to new hosts. Following the establishment of EA-swine lineage, we observed an increased frequency of intrasubtype reassortment of segments compared to the earlier strains that has been associated with adaptive amino acid replacements, disease severity and vaccine escape. Taken together, our study provides key insights into the adaptive changes in viral genomes following the transmission of avian influenza viruses to swine and the early establishment of the EA-swine lineage.

Prevalence of African swine fever virus and classical swine fever virus antibodies in pigs in Benue State, Nigeria.

Science.gov (United States)

Asambe, A; Sackey, A K B; Tekdek, L B

2018-03-01

This study investigated the prevalence of African swine fever virus (ASFV) and classical swine fever virus (CSFV) antibodies in pigs in Benue State, Nigeria. Serum samples were collected from a total of 460 pigs, including 416 from 74 piggeries and 44 from Makurdi slaughter slab. The samples were analysed using indirect enzyme-linked immunosorbent assay (ELISA) test kit to detect the presence of ASFV antibodies, while competitive ELISA test kit was used to detect antibodies to CSFV. Our findings showed a total ASF prevalence of 13 (2.8%), while prevalences of 7 (1.7%) and 6 (13.6%) were observed in piggeries and in Makurdi slaughter slab, respectively. However, no CSFV antibody sera were detected in this study. Relatively higher ASFV antibody-positive pigs were detected in the slaughter slab than in piggeries. The difference in prevalence of ASF between the two locations was significantly associated (p = 0.017). These findings suggest the presence of ASFV antibody-positive pig in Benue State, Nigeria. Continuous surveillance and monitoring of these diseases among pigs in Nigeria to prevent any fulminating outbreak are recommended.

Uncovering of Classical Swine Fever Virus adaptive response to vaccination by Next Generation Sequencing

DEFF Research Database (Denmark)

Fahnøe, Ulrik; Orton, Richard; Höper, Dirk

Next Generation Sequencing (NGS) has rapidly become the preferred technology in nucleotide sequencing, and can be applied to unravel molecular adaptation of RNA viruses such as Classical Swine Fever Virus (CSFV). However, the detection of low frequency variants within viral populations by NGS...... is affected by errors introduced during sample preparation and sequencing, and so far no definitive solution to this problem has been presented....

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.

Human Immunodeficiency Virus and Hepatitis C Virus Co-infection ...

African Journals Online (AJOL)

Human Immunodeficiency Virus and Hepatitis C Virus Co-infection in Cameroon: Investigation of the Genetic Diversity and Virulent ... AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search · USING AJOL · RESOURCES ... DNA sequencing, and bioinformatics tools for sequence management and analysis.

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.

Highly pathogenic avian influenza virus subtype H5N1 in Africa: a comprehensive phylogenetic analysis and molecular characterization of isolates.

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Giovanni Cattoli

Full Text Available Highly pathogenic avian influenza virus A/H5N1 was first officially reported in Africa in early 2006. Since the first outbreak in Nigeria, this virus spread rapidly to other African countries. From its emergence to early 2008, 11 African countries experienced A/H5N1 outbreaks in poultry and human cases were also reported in three of these countries. At present, little is known of the epidemiology and molecular evolution of A/H5N1 viruses in Africa. We have generated 494 full gene sequences from 67 African isolates and applied molecular analysis tools to a total of 1,152 A/H5N1 sequences obtained from viruses isolated in Africa, Europe and the Middle East between 2006 and early 2008. Detailed phylogenetic analyses of the 8 gene viral segments confirmed that 3 distinct sublineages were introduced, which have persisted and spread across the continent over this 2-year period. Additionally, our molecular epidemiological studies highlighted the association between genetic clustering and area of origin in a majority of cases. Molecular signatures unique to strains isolated in selected areas also gave us a clearer picture of the spread of A/H5N1 viruses across the continent. Mutations described as typical of human influenza viruses in the genes coding for internal proteins or associated with host adaptation and increased resistance to antiviral drugs have also been detected in the genes coding for transmembrane proteins. These findings raise concern for the possible human health risk presented by viruses with these genetic properties and highlight the need for increased efforts to monitor the evolution of A/H5N1 viruses across the African continent. They further stress how imperative it is to implement sustainable control strategies to improve animal and public health at a global level.

Identification of a novel cell culture adaptation site on the capsid of foot-and-mouth disease virus.

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Chamberlain, Kyle; Fowler, Veronica L; Barnett, Paul V; Gold, Sarah; Wadsworth, Jemma; Knowles, Nick J; Jackson, Terry

2015-09-01

Vaccination remains the most effective tool for control of foot-and-mouth disease both in endemic countries and as an emergency preparedness for new outbreaks. Foot-and-mouth disease vaccines are chemically inactivated virus preparations and the production of new vaccines is critically dependent upon cell culture adaptation of field viruses, which can prove problematic. A major driver of cell culture adaptation is receptor availability. Field isolates of foot-and-mouth disease virus (FMDV) use RGD-dependent integrins as receptors, whereas cell culture adaptation often selects for variants with altered receptor preferences. Previously, two independent sites on the capsid have been identified where mutations are associated with improved cell culture growth. One is a shallow depression formed by the three major structural proteins (VP1-VP3) where mutations create a heparan sulphate (HS)-binding site (the canonical HS-binding site). The other involves residues of VP1 and is located at the fivefold symmetry axis. For some viruses, changes at this site result in HS binding; for others, the receptors are unknown. Here, we report the identification of a novel site on VP2 where mutations resulted in an expanded cell tropism of a vaccine variant of A/IRN/87 (called A - ). Furthermore, we show that introducing the same mutations into a different type A field virus (A/TUR/2/2006) resulted in the same expanded cell culture tropism as the A/IRN/87 A -  vaccine variant. These observations add to the evidence for multiple cell attachment mechanisms for FMDV and may be useful for vaccine manufacture when cell culture adaptation proves difficult.

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

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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…

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...... region within the O1K B64 strain that inhibits replication in cattle. These chimeric infectious cDNA plasmids provide a basis for the analysis of FMDV pathogenicity and characterization of receptor utilization in vivo....

Educational Adaptation and Pan-Africanism: Trends in Africa.

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Marah, John Karefah

1987-01-01

European colonialists believed that Africans should be educated in African traditional values, and that Africans should be made into dedicated workers, not holders of power. The African nationalists of the 1960s, in contrast, rejected most of the arduous aspects of European education as instruments of domination, and lay the foundation for the…

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

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

2016-10-22

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.

The African diaspora: history, adaptation and health.

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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. Published by Elsevier Ltd.

Analysis of farmers’ adaptation to weather extremes in West African Sudan Savanna

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David Boansi

2017-06-01

Full Text Available There have been recent incidences of weather extremes in the West African Sudan Savanna and farmers have responded through implementation of relevant adaptation strategies. For a deeper insight into farmers’ adaptation to climatic shocks, this study documents farmers’ perception of recent changes in the local climate, and identifies factors that influence the number and choice of strategies implemented. Interdependencies among strategies are explored and joint and marginal probabilities of adoption estimated. Upper East Ghana and Southwest Burkina Faso are used as the case study regions. These regions were selected due to extreme reliance of inhabitants on agriculture for sustenance, and their recent exposure to weather extremes. Through estimation of a Poisson regression and multivariate probit model to identify the major factors that influence the number and choice of strategies adopted, we discover that, limited access to credit, markets, and extension services, smaller cropland area, and low level of mechanization could impede effective adaptation to weather extremes. To enhance farmers’ adaptive capacity, policy makers and various stakeholders need to contribute towards improving farmers’ access to credit, markets, and extension services, and implement measures to promote mechanization.

Discovery and Description of Ebola Zaire Virus in 1976 and Relevance to the West African Epidemic During 2013-2016.

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Breman, Joel G; Heymann, David L; Lloyd, Graham; McCormick, Joseph B; Miatudila, Malonga; Murphy, Frederick A; Muyembé-Tamfun, Jean-Jacques; Piot, Peter; Ruppol, Jean-François; Sureau, Pierre; van der Groen, Guido; Johnson, Karl M

2016-10-15

In 1976, the first cases of Ebola virus disease in northern Democratic Republic of the Congo (then referred to as Zaire) were reported. This article addresses who was responsible for recognizing the disease; recovering, identifying, and naming the virus; and describing the epidemic. Key scientific approaches used in 1976 and their relevance to the 3-country (Guinea, Sierra Leone, and Liberia) West African epidemic during 2013-2016 are presented. Field and laboratory investigations started soon after notification, in mid-September 1976, and included virus cell culture, electron microscopy (EM), immunofluorescence antibody (IFA) testing of sera, case tracing, containment, and epidemiological surveys. In 2013-2016, medical care and public health work were delayed for months until the Ebola virus disease epidemic was officially declared an emergency by World Health Organization, but research in pathogenesis, clinical presentation, including sequelae, treatment, and prevention, has increased more recently. Filoviruses were cultured and observed by EM in Antwerp, Belgium (Institute of Tropical Medicine); Porton Down, United Kingdom (Microbiological Research Establishment); and Atlanta, Georgia (Centers for Disease Control and Prevention). In Atlanta, serological testing identified a new virus. The 1976 outbreak (280 deaths among 318 cases) stopped in 2 years. Transmission indices (R 0 ) are higher in all 3 countries than in 1976. An international commission working harmoniously in laboratories and with local communities was essential for rapid success in 1976. Control and understanding of the recent West African outbreak were delayed because of late recognition and because authorities were overwhelmed by many patients and poor community involvement. Despite obstacles, research was a priority in 1976 and recently. Published by Oxford University Press for the Infectious Diseases Society of America 2016. This work is written by (a) US Government employee(s) and is in the

Rigid amphipathic fusion inhibitors demonstrate antiviral activity against African swine fever virus.

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Hakobyan, Astghik; Galindo, Inmaculada; Nañez, Almudena; Arabyan, Erik; Karalyan, Zaven; Chistov, Alexey A; Streshnev, Philipp P; Korshun, Vladimir A; Alonso, Covadonga; Zakaryan, Hovakim

2018-01-01

Rigid amphipathic fusion inhibitors (RAFIs) are a family of nucleoside derivatives that inhibit the infectivity of several enveloped viruses by interacting with virion envelope lipids and inhibiting fusion between viral and cellular membranes. Here we tested the antiviral activity of two RAFIs, 5-(Perylen-3-ylethynyl)-arabino-uridine (aUY11) and 5-(Perylen-3-ylethynyl)uracil-1-acetic acid (cm1UY11) against African swine fever virus (ASFV), for which no effective vaccine is available. Both compounds displayed a potent, dose-dependent inhibitory effect on ASFV infection in Vero cells. The major antiviral effect was observed when aUY11 and cm1UY11 were added at early stages of infection and maintained during the complete viral cycle. Furthermore, virucidal assay revealed a significant extracellular anti-ASFV activity for both compounds. We also found decrease in the synthesis of early and late viral proteins in Vero cells treated with cm1UY11. Finally, the inhibitory effect of aUY11 and cm1UY11 on ASFV infection in porcine alveolar macrophages was confirmed. Overall, our study has identified novel anti-ASFV compounds with potential for future therapeutic developments.

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

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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.

A pox on thee! Manipulation of the host immune system by myxoma virus and implications for viral-host co-adaptation.

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Zúñiga, Martha C

2002-09-01

The poxviruses have evolved a diverse array of proteins which serve to subvert innate and adaptive host responses that abort or at least limit viral infections. Myxoma virus and its rabbit host are considered to represent an ideal poxvirus-host system in which to study the effects of these immunomodulatory proteins. Studies of laboratory rabbits (Oryctolagus cuniculus) infected with gene knockout variants of myxoma virus have provided compelling evidence that several myxoma virus gene products contribute to the pathogenic condition known as myxomatosis. However, myxomatosis, which is characterized by skin lesions, systemic immunosuppression, and a high mortality rate, does not occur in the virus' natural South American host, Sylvilogus brasiliensis. Moreover, in Australia where myxoma virus was willfully introduced to control populations of O. cuniculus, myxomatosis-resistant rabbits emerged within a year of myxoma virus introduction into the field. In this review I discuss the characterized immunomodulatory proteins of myxoma virus, their biochemical properties, their pathogenic effects in laboratory rabbits, the role of the host immune system in the susceptibility or resistance to myxomatosis, and the evidence that immunomodulatory genes may have been attenuated during the co-adaptation of myxoma virus and O. cuniculus in Australia.

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

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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...

Cutting edge: impairment of dendritic cells and adaptive immunity by Ebola and Lassa viruses.

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Mahanty, Siddhartha; Hutchinson, Karen; Agarwal, Sudhanshu; McRae, Michael; Rollin, Pierre E; Pulendran, Bali

2003-03-15

Acute infection of humans with Ebola and Lassa viruses, two principal etiologic agents of hemorrhagic fevers, often results in a paradoxical pattern of immune responses: early infection, characterized by an outpouring of inflammatory mediators such as TNF-alpha, IL-1 beta, and IL-6, vs late stage infections, which are associated with poor immune responses. The mechanisms underlying these diverse outcomes are poorly understood. In particular, the role played by cells of the innate immune system, such as dendritic cells (DC), is not known. In this study, we show that Ebola and Lassa viruses infect human monocyte-derived DC and impair their function. Monocyte-derived DC exposed to either virus fail to secrete proinflammatory cytokines, do not up-regulate costimulatory molecules, and are poor stimulators of T cells. These data represent the first evidence for a mechanism by which Ebola and Lassa viruses target DC to impair adaptive immunity.

African Health Sciences

African Journals Online (AJOL)

African Health Sciences is an open access, free online, internationally ... Ebola virus disease: assessment of knowledge, attitude and practice of nursing ... and immune system modulation by aerobic versus resisted exercise training for elderly ...

Laboratory investigations of African Pouched Rats (Cricetomys gambianus) as a potential reservoir host species for Monkeypox Virus

Science.gov (United States)

Hutson, Christina L.; Nakazawa, Yoshinori J.; Self, Joshua; Olson, Victoria A.; Regnery, Russell L.; Braden, Zachary; Weiss, Sonja; Malekani, Jean; Jackson, Eddie; Tate, Mallory; Karem, Kevin L.; Rocke, Tonie E.; Osorio, Jorge E.; Damon, Inger K.; Carroll, Darin S.

2015-01-01

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 1X108pfu/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.

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.

East African cassava mosaic-like viruses from Africa to Indian ocean islands: molecular diversity, evolutionary history and geographical dissemination of a bipartite begomovirus

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De Bruyn Alexandre

2012-11-01

Full Text Available Abstract Background Cassava (Manihot esculenta is a major food source for over 200 million sub-Saharan Africans. Unfortunately, its cultivation is severely hampered by cassava mosaic disease (CMD. Caused by a complex of bipartite cassava mosaic geminiviruses (CMG species (Family: Geminivirideae; Genus: Begomovirus CMD has been widely described throughout Africa and it is apparent that CMG's are expanding their geographical distribution. Determining where and when CMG movements have occurred could help curtail its spread and reveal the ecological and anthropic factors associated with similar viral invasions. We applied Bayesian phylogeographic inference and recombination analyses to available and newly described CMG sequences to reconstruct a plausible history of CMG diversification and migration between Africa and South West Indian Ocean (SWIO islands. Results The isolation and analysis of 114 DNA-A and 41 DNA-B sequences demonstrated the presence of three CMG species circulating in the Comoros and Seychelles archipelagos (East African cassava mosaic virus, EACMV; East African cassava mosaic Kenya virus, EACMKV; and East African cassava mosaic Cameroon virus, EACMCV. Phylogeographic analyses suggest that CMG’s presence on these SWIO islands is probably the result of at least four independent introduction events from mainland Africa occurring between 1988 and 2009. Amongst the islands of the Comoros archipelago, two major migration pathways were inferred: One from Grande Comore to Mohéli and the second from Mayotte to Anjouan. While only two recombination events characteristic of SWIO islands isolates were identified, numerous re-assortments events were detected between EACMV and EACMKV, which seem to almost freely interchange their genome components. Conclusions Rapid and extensive virus spread within the SWIO islands was demonstrated for three CMG complex species. Strong evolutionary or ecological interaction between CMG species may explain

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

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

2016-10-21

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.

Estimation of the transmission dynamics of African swine fever virus within a swine house

DEFF Research Database (Denmark)

Nielsen, J. P.; Larsen, T. S.; Hisham Beshara Halasa, Tariq

2017-01-01

The spread of African swine fever virus (ASFV) threatens to reach further parts of Europe. In countries with a large swine production, an outbreak of ASF may result in devastating economic consequences for the swine industry. Simulation models can assist decision makers setting up contingency plans......·00 (95% CI 0-1). Furthermore, we simulated the spread of ASFV within a pig house using a modified SEIR-model to establish the time from infection of one animal until ASFV is detected in the herd. Based on a chosen detection limit of 2·55% equivalent to 10 dead pigs out of 360, the disease would...

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

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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.

Cytomegalovirus-Driven Adaptive-Like Natural Killer Cell Expansions Are Unaffected by Concurrent Chronic Hepatitis Virus Infections

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David F. G. Malone

2017-05-01

Full Text Available Adaptive-like expansions of natural killer (NK cell subsets are known to occur in response to human cytomegalovirus (CMV infection. These expansions are typically made up of NKG2C+ NK cells with particular killer-cell immunoglobulin-like receptor (KIR expression patterns. Such NK cell expansion patterns are also seen in patients with viral hepatitis infection. Yet, it is not known if the viral hepatitis infection promotes the appearance of such expansions or if effects are solely attributed to underlying CMV infection. In sizeable cohorts of CMV seropositive hepatitis B virus (HBV, hepatitis C virus (HCV, and hepatitis delta virus (HDV infected patients, we analyzed NK cells for expression of NKG2A, NKG2C, CD57, and inhibitory KIRs to assess the appearance of NK cell expansions characteristic of what has been seen in CMV seropositive healthy individuals. Adaptive-like NK cell expansions observed in viral hepatitis patients were strongly associated with CMV seropositivity. The number of subjects with these expansions did not differ between CMV seropositive viral hepatitis patients and corresponding healthy controls. Hence, we conclude that adaptive-like NK cell expansions observed in HBV, HCV, and/or HDV infected individuals are not caused by the chronic hepatitis infections per se, but rather are a consequence of underlying CMV infection.

Health evaluation of African penguins (Spheniscus demersus in southern Africa

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Nola J. Parsons

2016-09-01

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.

NEWS for Africa: adaptation and reliability of a built environment questionnaire for physical activity in seven African countries.

Science.gov (United States)

Oyeyemi, Adewale L; Kasoma, Sandra S; Onywera, Vincent O; Assah, Felix; Adedoyin, Rufus A; Conway, Terry L; Moss, Sarah J; Ocansey, Reginald; Kolbe-Alexander, Tracy L; Akinroye, Kingsley K; Prista, Antonio; Larouche, Richard; Gavand, Kavita A; Cain, Kelli L; Lambert, Estelle V; Aryeetey, Richmond; Bartels, Clare; Tremblay, Mark S; Sallis, James F

2016-03-08

Built environment and policy interventions are effective strategies for controlling the growing worldwide deaths from physical inactivity-related non-communicable diseases. To improve built environment research and develop African specific evidence, it is important to first tailor built environment measures to African contexts and assess their psychometric properties across African countries. This study reports on the adaptation and test-retest reliability of the Neighborhood Environment Walkability Scale in seven sub-Saharan African countries (NEWS-Africa). The original NEWS comprising 8 subscales measuring reported physical and social attributes of neighborhood environments was systematically adapted for Africa through extensive input from physical activity and public health researchers, built environment professionals, and residents in seven African countries: Cameroon, Ghana, Kenya, Mozambique, Nigeria, South Africa and Uganda. Cognitive testing of NEWS-Africa was conducted among diverse residents (N = 109, 50 youth [12 - 17 years] and 59 adults [22 - 67 years], 69 % from low socioeconomic status [SES] neighborhoods). NEWS-Africa was translated into local languages and evaluated for 2-week test-retest reliability in adult participants (N = 301; female = 50.2 %; age = 32.3 ± 12.9 years) purposively recruited from neighborhoods varying in walkability (high and low walkable) and SES (high and low income) and from villages in six of seven participating countries. The original 67 NEWS items was expanded to 89 scores (76 individual NEWS items and 13 computed scales). Several modifications were made to individual items, and some new items were added to capture important attributes in the African environment. A new scale on personal safety was created, and the aesthetics scale was enlarged to reflect African specific characteristics. Over 95 % of all NEWS-Africa scores (items plus computed scales) demonstrated evidence of "excellent" (ICCs�

Intervention Mapping to Adapt Evidence-Based Interventions for Use in Practice: Increasing Mammography among African American Women

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Linda Highfield

2015-01-01

Full Text Available This paper describes and demonstrates the use of the systematic planning process, Intervention Mapping, to adapt an evidence-based public health intervention (EBI. We used a simplified version of Intervention Mapping (IM Adapt to increase an intervention’s fit with a new setting and population. IM Adapt guides researchers and practitioners in selecting an EBI, making decisions about whether and what to adapt, and executing the adaptation while guarding the EBI’s essential elements (those responsible for effectiveness. We present a case study of a project in which we used IM Adapt to find, adapt, implement, and evaluate an EBI to improve mammography adherence for African American women in a new practice setting in Houston, Texas. IM Adapt includes the following (1 assess needs and organizational capacity; (2 find EBIs; (3 plan adaptations based on fit assessments; (4 make adaptations; (5 plan for implementation; and (6 plan for evaluation of the adapted EBI. The case study shows an example of how public health researchers and practitioners can use the tool to make it easier to find and use EBIs, thus encouraging greater uptake. IM Adapt adds to existing dissemination and adaptation models by providing detailed guidance on how to decide on effective adaptation, while maintaining the essential elements of the EBI.

Intervention Mapping to Adapt Evidence-Based Interventions for Use in Practice: Increasing Mammography among African American Women.

Science.gov (United States)

Highfield, Linda; Hartman, Marieke A; Mullen, Patricia Dolan; Rodriguez, Serena A; Fernandez, Maria E; Bartholomew, L Kay

2015-01-01

This paper describes and demonstrates the use of the systematic planning process, Intervention Mapping, to adapt an evidence-based public health intervention (EBI). We used a simplified version of Intervention Mapping (IM Adapt) to increase an intervention's fit with a new setting and population. IM Adapt guides researchers and practitioners in selecting an EBI, making decisions about whether and what to adapt, and executing the adaptation while guarding the EBI's essential elements (those responsible for effectiveness). We present a case study of a project in which we used IM Adapt to find, adapt, implement, and evaluate an EBI to improve mammography adherence for African American women in a new practice setting in Houston, Texas. IM Adapt includes the following (1) assess needs and organizational capacity; (2) find EBIs; (3) plan adaptations based on fit assessments; (4) make adaptations; (5) plan for implementation; and (6) plan for evaluation of the adapted EBI. The case study shows an example of how public health researchers and practitioners can use the tool to make it easier to find and use EBIs, thus encouraging greater uptake. IM Adapt adds to existing dissemination and adaptation models by providing detailed guidance on how to decide on effective adaptation, while maintaining the essential elements of the EBI.

Molecular phylogeny of Duvenhage virus

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Louis H. Nel

2011-11-01

Full Text Available The Duvenhage virus (DUVV constitutes one of the 11 species in the Lyssavirus genus and causes fatal rabies encephalitis. The virus is associated with insectivorous bat species and three human cases have been reported, all of which were linked to contact with bats. Few of these isolates have been studied and thus little is known about the phylogeny and epidemiology of this lyssavirus. Until 2007, when an isolate was made from the East African country of Kenya, all isolations of this virus had been from southern Africa. This discovery led to many questions regarding the spread and diversity of this lyssavirus. Phylogenetic analysis indicated that the DUVV isolates constitute two different lineages, in which the southern African isolates group together to form one lineage and the more recent isolate from Kenya constitutes a new, second lineage. We found that the new isolate has a genetic variation that has not yet been seen for DUVV. Not only is our lack of knowledge regarding the geographical distribution of this uniquely African virus emphasised, but we have also demonstrated the potential diversity within this genotype.

Equine H7N7 influenza A viruses are highly pathogenic in mice without adaptation: potential use as an animal model.

OpenAIRE

Kawaoka, Y

1991-01-01

Equine H7N7 influenza A viruses, representing a broad range of isolates, were lethal in mice without adaptation. After repeated passages, A/Equine/London/1416/73 acquired neurotropism upon intranasal infection. Thus, mice infected with equine influenza A viruses provide a model system for the study of highly virulent mammalian influenza viruses.

Autologous Stem Cell Transplantation Disrupts Adaptive Immune Responses during Rebound Simian/Human Immunodeficiency Virus Viremia.

Science.gov (United States)

Reeves, Daniel B; Peterson, Christopher W; Kiem, Hans-Peter; Schiffer, Joshua T

2017-07-01

Primary HIV-1 infection induces a virus-specific adaptive/cytolytic immune response that impacts the plasma viral load set point and the rate of progression to AIDS. Combination antiretroviral therapy (cART) suppresses plasma viremia to undetectable levels that rebound upon cART treatment interruption. Following cART withdrawal, the memory component of the virus-specific adaptive immune response may improve viral control compared to primary infection. Here, using primary infection and treatment interruption data from macaques infected with simian/human immunodeficiency virus (SHIV), we observe a lower peak viral load but an unchanged viral set point during viral rebound. The addition of an autologous stem cell transplant before cART withdrawal alters viral dynamics: we found a higher rebound set point but similar peak viral loads compared to the primary infection. Mathematical modeling of the data that accounts for fundamental immune parameters achieves excellent fit to heterogeneous viral loads. Analysis of model output suggests that the rapid memory immune response following treatment interruption does not ultimately lead to better viral containment. Transplantation decreases the durability of the adaptive immune response following cART withdrawal and viral rebound. Our model's results highlight the impact of the endogenous adaptive immune response during primary SHIV infection. Moreover, because we capture adaptive immune memory and the impact of transplantation, this model will provide insight into further studies of cure strategies inspired by the Berlin patient. IMPORTANCE HIV patients who interrupt combination antiretroviral therapy (cART) eventually experience viral rebound, the return of viral loads to pretreatment levels. However, the "Berlin patient" remained free of HIV rebound over a decade after stopping cART. His cure is attributed to leukemia treatment that included an HIV-resistant stem cell transplant. Inspired by this case, we studied the impact

Evolution and adaptation of the pandemic A/H1N1 2009 influenza virus

Directory of Open Access Journals (Sweden)

Ducatez MF

2011-07-01

Full Text Available Mariette F Ducatez, Thomas P Fabrizio, Richard J WebbyDepartment of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN, USAAbstract: The emergence of the 2009 H1N1 pandemic influenza virus [A(H1N1pdm09] has provided the public health community with many challenges, but also the scientific community with an opportunity to monitor closely its evolution through the processes of drift and shift. To date, and despite having circulated in humans for nearly two years, little antigenic variation has been observed in the A(H1N1pdm09 viruses. However, as the A(H1N1pdm09 virus continues to circulate and the immunologic pressure within the human population increases, future antigenic change is almost a certainty. Several coinfections of A(H1N1pdm09 and seasonal A(H1N1 or A(H3N2 viruses have been observed, but no reassortant viruses have been described in humans, suggesting a lack of fitness of reassortant viruses or a lack of opportunities for interaction of different viral lineages. In contrast, multiple reassortment events have been detected in swine populations between A(H1N1 pdm09 and other endemic swine viruses. Somewhat surprisingly, many of the well characterized influenza virus virulence markers appear to have limited impact on the phenotype of the A(H1N1pdm09 viruses when they have been introduced into mutant viruses in laboratory settings. As such, it is unclear what the evolutionary path of the pandemic virus will be, but the monitoring of any changes in the circulating viruses will remain a global public and animal health priority.Keywords: influenza, pandemic, evolution, adaptation

[Herpesvirus detection in clinically healthy West African mud turtles (Pelusioscastaneus)].

Science.gov (United States)

Marschang, R E; Heckers, K O; Heynol, V; Weider, K; Behncke, H

2015-01-01

First description of a herpesvirus in West African mud turtles. A herpesvirus was detected in two clinically healthy West African mud turtles (Pelusios castaneus) by PCR during a quarantine exam. The animals had been imported from Togo, West Africa to Germany for the pet trade. Analysis of a portion of the genome of the detected virus showed that it is a previously unknown virus related to other chelonid herpesviruses. The virus was named pelomedusid herpesvirus 1. This case highlights the importance of testing for infectious agents during quarantine, even in clinically healthy animals.

A live attenuated cold-adapted influenza A H7N3 virus vaccine provides protection against homologous and heterologous H7 viruses in mice and ferrets

International Nuclear Information System (INIS)

Joseph, Tomy; McAuliffe, Josephine; Lu, Bin; Vogel, Leatrice; Swayne, David; Jin, Hong; Kemble, George; Subbarao, Kanta

2008-01-01

The appearance of human infections caused by avian influenza A H7 subtype viruses underscores their pandemic potential and the need to develop vaccines to protect humans from viruses of this subtype. A live attenuated H7N3 virus vaccine was generated by reverse genetics using the HA and NA genes of a low pathogenicity A/chicken/BC/CN-6/04 (H7N3) virus and the six internal protein genes of the cold-adapted A/Ann Arbor/6/60 ca (H2N2) virus. The reassortant H7N3 BC 04 ca vaccine virus was temperature sensitive and showed attenuation in mice and ferrets. Intranasal immunization with one dose of the vaccine protected mice and ferrets when challenged with homologous and heterologous H7 viruses. The reassortant H7N3 BC 04 ca vaccine virus showed comparable levels of attenuation, immunogenicity and efficacy in mice and ferret models. The safety, immunogenicity, and efficacy of this vaccine in mice and ferrets support the evaluation of this vaccine in clinical trials

Identification of Wild Boar-Habitat Epidemiologic Cycle in African Swine Fever Epizootic.

Science.gov (United States)

Chenais, Erika; Ståhl, Karl; Guberti, Vittorio; Depner, Klaus

2018-04-01

The African swine fever epizootic in central and eastern European Union member states has a newly identified component involving virus transmission by wild boar and virus survival in the environment. Insights led to an update of the 3 accepted African swine fever transmission models to include a fourth cycle: wild boar-habitat.

Vector Competence of American Mosquitoes for Three Strains of Zika Virus.

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James Weger-Lucarelli

2016-10-01

Full Text Available In 2015, Zika virus (ZIKV; Flaviviridae; Flavivirus emerged in the Americas, causing millions of infections in dozens of countries. The rapid spread of the virus and the association with disease outcomes such as Guillain-Barré syndrome and microcephaly make understanding transmission dynamics essential. Currently, there are no reports of vector competence (VC of American mosquitoes for ZIKV isolates from the Americas. Further, it is not clear whether ZIKV strains from other genetic lineages can be transmitted by American Aedes aegypti populations, and whether the scope of the current epidemic is in part facilitated by viral factors such as enhanced replicative fitness or increased vector competence. Therefore, we characterized replication of three ZIKV strains, one from each of the three phylogenetic clades in several cell lines and assessed their abilities to be transmitted by Ae. aegypti mosquitoes. Additionally, laboratory colonies of different Culex spp. were infected with an American outbreak strain of ZIKV to assess VC. Replication rates were variable and depended on virus strain, cell line and MOI. African strains used in this study outcompeted the American strain in vitro in both mammalian and mosquito cell culture. West and East African strains of ZIKV tested here were more efficiently transmitted by Ae. aegypti from Mexico than was the currently circulating American strain of the Asian lineage. Long-established laboratory colonies of Culex mosquitoes were not efficient ZIKV vectors. These data demonstrate the capacity for additional ZIKV strains to infect and replicate in American Aedes mosquitoes and suggest that neither enhanced virus replicative fitness nor virus adaptation to local vector mosquitoes seems likely to explain the extent and intensity of ZIKV transmission in the Americas.

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...

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...

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

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...... (HC-TN and DH6), 1b (DH1 and DH5), and 3a (DBN) isolates, using previously identified adaptive mutations. Introduction of mutations from isolates of the same subtype either led to immediate efficient virus production or accelerated culture adaptation. The DH6 and DH5 recombinants without introduced...... mutations did not adapt to culture. Universal adaptive effects of mutations in NS3 (Q1247L, I1312V, K1398Q, R1408W, and Q1496L) and NS5A (V2418L) were investigated for JFH1-based genotype 1 to 5 core-NS2 recombinants; several mutations conferred adaptation to H77C (1a), J4 (1b), S52 (3a), and SA13 (5a...

Identification of Wild Boar–Habitat Epidemiologic Cycle in African Swine Fever Epizootic

Science.gov (United States)

Ståhl, Karl; Guberti, Vittorio; Depner, Klaus

2018-01-01

The African swine fever epizootic in central and eastern European Union member states has a newly identified component involving virus transmission by wild boar and virus survival in the environment. Insights led to an update of the 3 accepted African swine fever transmission models to include a fourth cycle: wild boar–habitat. PMID:29553337

Editorial | Weyer | South African Medical Journal

African Journals Online (AJOL)

Ebola virus disease in West Africa – South African perspectives. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners ...

Evidence of expanded host range and mammalian-associated genetic changes in a duck H9N2 influenza virus following adaptation in quail and chickens.

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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.

Adaptation

International Development Research Centre (IDRC) Digital Library (Canada)

building skills, knowledge or networks on adaptation, ... the African partners leading the AfricaAdapt network, together with the UK-based Institute of Development Studies; and ... UNCCD Secretariat, Regional Coordination Unit for Africa, Tunis, Tunisia .... 26 Rural–urban Cooperation on Water Management in the Context of.

Thy1+ NK [corrected] cells from vaccinia virus-primed mice confer protection against vaccinia virus challenge in the absence of adaptive lymphocytes.

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Geoffrey O Gillard

2011-08-01

Full Text Available While immunological memory has long been considered the province of T- and B-lymphocytes, it has recently been reported that innate cell populations are capable of mediating memory responses. We now show that an innate memory immune response is generated in mice following infection with vaccinia virus, a poxvirus for which no cognate germline-encoded receptor has been identified. This immune response results in viral clearance in the absence of classical adaptive T and B lymphocyte populations, and is mediated by a Thy1(+ subset of natural killer (NK cells. We demonstrate that immune protection against infection from a lethal dose of virus can be adoptively transferred with memory hepatic Thy1(+ NK cells that were primed with live virus. Our results also indicate that, like classical immunological memory, stronger innate memory responses form in response to priming with live virus than a highly attenuated vector. These results demonstrate that a defined innate memory cell population alone can provide host protection against a lethal systemic infection through viral clearance.

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

In East Africa, the foot-and-mouth disease (FMD) virus (FMDV) isolates have over time included serotypes O, A, C, Southern African Territories (SAT) 1 and SAT 2, mainly from livestock. SAT 3 has only been isolated in a few cases and only in African buffalos (Syncerus caffer). To investigate...... 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...... screened using Ceditest® FMDV NS to detect antibodies against FMDV non-structural proteins (NSP). The seroprevalence of antibodies against non-structural proteins was 74%. To characterize FMDV antibodies, samples were selected and titrated using serotype-specific solid phase blocking enzyme linked...

Molecular Characterization of the Kamese Virus, an Unassigned Rhabdovirus, Isolated from Culex pruina in the Central African Republic.

Science.gov (United States)

Simo Tchetgna, Huguette Dorine; Nakoune, Emmanuel; Selekon, Benjamin; Gessain, Antoine; Manuguerra, Jean-Claude; Kazanji, Mirdad; Berthet, Nicolas

2017-06-01

Rhabdoviridae is one of the most diversified families of RNA viruses whose members infect a wide range of plants, animals, and arthropods. The members of this family are classified into 13 genera and >150 unassigned viruses. Here, we sequenced the complete genome of a rhabdovirus belonging to the Hart Park serogroup, the Kamese virus (KAMV), isolated in 1977 from Culex pruina in the Central African Republic. The genomic sequence showed an organization typical of rhabdoviruses with additional genes in the P-M and G-L intergenic regions, as already reported for the Hart Park serogroup. Our Kamese strain (ArB9074) had 98% and 78.8% nucleotide sequence similarity with the prototypes of the KAMV and Mossuril virus isolated in Uganda and Mozambique in two different Culex species, respectively. Moreover, the protein sequences had 98-100% amino acid similarity with the prototype of the KAMV, except for an additional gene (U3) that showed a divergence of 6%. These molecular data show that our strain of the KAMV is genetically close to the Culex annuliorus strain that was circulating in Uganda in 1967. However, this study suggests the need to improve our knowledge of the KAMV to better understand its behavior, its life cycle, and its potential reservoirs.

Extensive copy number variations in admixed Indian population of African ancestry: potential involvement in adaptation.

Science.gov (United States)

Narang, Ankita; Jha, Pankaj; Kumar, Dhirendra; Kutum, Rintu; Mondal, Anupam Kumar; Dash, Debasis; Mukerji, Mitali

2014-11-13

Admixture mapping has been enormously resourceful in identifying genetic variations linked to phenotypes, adaptation, and diseases. In this study through analysis of copy number variable regions (CNVRs), we report extensive restructuring in the genomes of the recently admixed African-Indian population (OG-W-IP) that inhabits a highly saline environment in Western India. The study included subjects from OG-W-IP (OG), five different Indian and three HapMap populations that were genotyped using Affymetrix version 6.0 arrays. Copy number variations (CNVs) detected using Birdsuite were used to define CNVRs. Population structure with respect to CNVRs was delineated using random forest approach. OG genomes have a surprising excess of CNVs in comparison to other studied populations. Individual ancestry proportions computed using STRUCTURE also reveals a unique genetic component in OGs. Population structure analysis with CNV genotypes indicates OG to be distant from both the African and Indian ancestral populations. Interestingly, it shows genetic proximity with respect to CNVs to only one Indian population IE-W-LP4, which also happens to reside in the same geographical region. We also observe a significant enrichment of molecular processes related to ion binding and receptor activity in genes encompassing OG-specific CNVRs. Our results suggest that retention of CNVRs from ancestral natives and de novo acquisition of CNVRs could accelerate the process of adaptation especially in an extreme environment. Additionally, this population would be enormously useful for dissecting genes and delineating the involvement of CNVs in salt adaptation. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Geographic range of vector-borne infections and their vectors: the role of African wildlife.

Science.gov (United States)

van Vuuren, M; Penzhorn, B L

2015-04-01

The role of African wildlife in the occurrence of vector-borne infections in domestic animals has gained renewed interest as emerging and re-emerging infections occur worldwide at an increasing rate. In Africa, biodiversity conservation and the expansion of livestock production have increased the risk of transmitting vector-borne infections between wildlife and livestock. The indigenous African pathogens with transboundary potential, such as Rift Valley fever virus, African horse sickness virus, bluetongue virus, lumpy skin disease virus, African swine fever virus, and blood-borne parasites have received the most attention. There is no evidence for persistent vector-borne viral infections in African wildlife. For some viral infections, wildlife may act as a reservoir through the inter-epidemic circulation of viruses with mild or subclinical manifestations. Wildlife may also act as introductory or transporting hosts when moved to new regions, e.g. for lumpy skin disease virus, Rift Valley fever virus and West Nile virus. Wildlife may also act as amplifying hosts when exposed to viruses in the early part of the warm season when vectors are active, with spillover to domestic animals later in the season, e.g. with bluetongue and African horse sickness. Some tick species found on domestic animals are more abundant on wildlife hosts; some depend on wildlife hosts to complete their life cycle. Since the endemic stability of a disease depends on a sufficiently large tick population to ensure that domestic animals become infected at an early age, the presence of wildlife hosts that augment tick numbers may be beneficial. Many wild ungulate species are reservoirs of Anaplasma spp., while the role of wildlife in the epidemiology of heartwater (Ehrlichia ruminantium infection) has not been elucidated. Wild ungulates are not usually reservoirs of piroplasms that affect livestock; however, there are two exceptions: zebra, which are reservoirs of Babesia caballi and Theileria

Immune responses to recombinants of the South African vaccine strain of lumpy skin disease virus generated by using thymidine kinase gene insertion.

Science.gov (United States)

Wallace, David B; Viljoen, Gerrit J

2005-04-27

The South African vaccine strain of lumpy skin disease virus (type SA-Neethling) is currently being developed as a vector for recombinant vaccines of economically important livestock diseases throughout Africa. In this study, the feasibility of using the viral thymidine kinase gene as the site of insertion was investigated and recombinant viruses were evaluated in animal trials. Two separate recombinants were generated and selected for homogeneity expressing either the structural glycoprotein gene of bovine ephemeral fever virus (BEFV) or the two structural glycoprotein genes of Rift Valley fever virus (RVFV). Both recombinants incorporate the enhanced green fluorescent protein (EGFP) as a visual marker and the Escherichia coli guanine phosphoribosyl transferase (gpt) gene for dominant positive selection. The LSDV-RVFV recombinant construct (rLSDV-RVFV) protected mice against virulent RVFV challenge. In a small-scale BEFV-challenge cattle trial the rLSDV-BEFV construct failed to fully protect the cattle against virulent challenge, although both a humoral and cellular BEFV-specific immune response was elicited.

Isolation and molecular characterization of Chikungunya virus from the Andaman and Nicobar archipelago, India: evidence of an East, Central, and South African genotype.

Science.gov (United States)

Muruganandam, N; Chaaithanya, I K; Senthil, G S; Shriram, A N; Bhattacharya, D; Jeevabharathi, G S; Sudeep, A B; Pradeepkumar, N; Vijayachari, P

2011-12-01

Chikungunya virus (CHIKV) is an Alphavirus belonging to the family Togaviridae. In 2006, CHIKV infection struck the Andaman and Nicobar archipelago, with an attack rate of 60%. There were more than 10 cases with acute flaccid paralysis simulating the Guillian Barre Syndrome. The majority of the patients presented severe joint pain. The cause for such an explosive nature of the outbreak with increased morbidity was not known. The isolation of CHIKV was attempted and succeeded from nine subjects presenting clinical symptoms of Chikungunya fever. The cDNA of all the isolates was sequenced for partial E1 and nsP1 genes. Sequences were aligned based on the double locus sequence typing concept. The phylogenetic analysis shows that sequences of Andaman isolates grouped with the East, Central, and South African genotype of virus isolates from India, Sri Lanka, and Réunion. The genetic distance between Andaman isolates and the Réunion isolates was very small. The phylogenetic analysis confirmed the origin of the isolates responsible for the first ever confirmed CHIKV outbreak in these islands to be the East, Central, and South African genotype. In this manuscript, we discuss the involvement of the East, Central, and South African strain with the Chikungunya fever outbreak in this archipelago and double locus sequence typing as a first time approach.

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

Genomic footprints of dryland stress adaptation in Egyptian fat-tail sheep and their divergence from East African and western Asia cohorts.

Science.gov (United States)

Mwacharo, Joram M; Kim, Eui-Soo; Elbeltagy, Ahmed R; Aboul-Naga, Adel M; Rischkowsky, Barbara A; Rothschild, Max F

2017-12-15

African indigenous sheep are classified as fat-tail, thin-tail and fat-rump hair sheep. The fat-tail are well adapted to dryland environments, but little is known on their genome profiles. We analyzed patterns of genomic variation by genotyping, with the Ovine SNP50K microarray, 394 individuals from five populations of fat-tail sheep from a desert environment in Egypt. Comparative inferences with other East African and western Asia fat-tail and European sheep, reveal at least two phylogeographically distinct genepools of fat-tail sheep in Africa that differ from the European genepool, suggesting separate evolutionary and breeding history. We identified 24 candidate selection sweep regions, spanning 172 potentially novel and known genes, which are enriched with genes underpinning dryland adaptation physiology. In particular, we found selection sweeps spanning genes and/or pathways associated with metabolism; response to stress, ultraviolet radiation, oxidative stress and DNA damage repair; activation of immune response; regulation of reproduction, organ function and development, body size and morphology, skin and hair pigmentation, and keratinization. Our findings provide insights on the complexity of genome architecture regarding dryland stress adaptation in the fat-tail sheep and showcase the indigenous stocks as appropriate genotypes for adaptation planning to sustain livestock production and human livelihoods, under future climates.

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

Directory of Open Access Journals (Sweden)

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.

Climate change adaptation in Africa : annual report 2006-2007

International Nuclear Information System (INIS)

2007-01-01

The Climate Change Adaptation Program was developed by Canada's International Development Research Centre and the United Kingdom's Department for International Development in order to address the needs of African communities vulnerable to climate change. The objectives of the program are to strengthen the capacity of African scientists, organization and communities to contribute to adaptation to climate change, as well as to generate a better understanding of climate change adaptation, and to support adaptation strategies and their adoption by rural and urban Africans. This annual report provided details of the first year of the program's implementation, in which an advisory board was established in order to balance donor representation and African expertise in adaptation. The first year of the program also saw the recruitment of a 13 person staff and the development of proposals for the first allocation of funding. A financial summary was provided. The report provided details of outreach and communications activities used to introduce the program to African and international audiences. 3 tabs., 44 figs

Porcine Epidemic Diarrhea Virus 3C-Like Protease-Mediated Nucleocapsid Processing: Possible Link to Viral Cell Culture Adaptability.

Science.gov (United States)

Jaru-Ampornpan, Peera; Jengarn, Juggragarn; Wanitchang, Asawin; Jongkaewwattana, Anan

2017-01-15

Porcine epidemic diarrhea virus (PEDV) causes severe diarrhea and high mortality rates in newborn piglets, leading to massive losses to the swine industry worldwide during recent epidemics. Intense research efforts are now focusing on defining viral characteristics that confer a growth advantage, pathogenicity, or cell adaptability in order to better understand the PEDV life cycle and identify suitable targets for antiviral or vaccine development. Here, we report a unique phenomenon of PEDV nucleocapsid (N) cleavage by the PEDV-encoded 3C-like protease (3Cpro) during infection. The identification of the 3Cpro cleavage site at the C terminus of N supported previous observations that PEDV 3Cpro showed a substrate requirement slightly different from that of severe acute respiratory syndrome coronavirus (SARS-CoV) 3Cpro and revealed a greater flexibility in its substrate recognition site. This cleavage motif is present in the majority of cell culture-adapted PEDV strains but is missing in emerging field isolates. Remarkably, reverse-genetics-derived cell culture-adapted PEDV AVCT12 harboring uncleavable N displayed growth retardation in Vero E6-APN cells compared to the wild-type virus. These observations altogether shed new light on the investigation and characterization of the PEDV nucleocapsid protein and its possible link to cell culture adaptation. Recurrent PEDV outbreaks have resulted in enormous economic losses to swine industries worldwide. To gain the upper hand in combating this disease, it is necessary to understand how this virus replicates and evades host immunity. Characterization of viral proteins provides important clues to mechanisms by which viruses survive and spread. Here, we characterized an intriguing phenomenon in which the nucleocapsids of some PEDV strains are proteolytically processed by the virally encoded main protease. Growth retardation in recombinant PEDV carrying uncleavable N suggests a replication advantage provided by the cleavage

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

Directory of Open Access Journals (Sweden)

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.

Directed genetic modification of African horse sickness virus by reverse genetics

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Elaine Vermaak

2015-07-01

Full Text Available African horse sickness virus (AHSV, a member of the Orbivirus genus in the family Reoviridae, is an arthropod-transmitted pathogen that causes a devastating disease in horses with a mortality rate greater than 90%. Fundamental research on AHSV and the development of safe, efficacious vaccines could benefit greatly from an uncomplicated genetic modification method to generate recombinant AHSV. We demonstrate that infectious AHSV can be recovered by transfection of permissive mammalian cells with transcripts derived in vitro from purified AHSV core particles. These findings were expanded to establish a genetic modification system for AHSV that is based on transfection of the cells with a mixture of purified core transcripts and a synthetic T7 transcript. This approach was applied successfully to recover a directed cross-serotype reassortant AHSV and to introduce a marker sequence into the viral genome. The ability to manipulate the AHSV genome and engineer specific mutants will increase understanding of AHSV replication and pathogenicity, as well as provide a tool for generating designer vaccine strains.

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

2014-11-01

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.

78 FR 67175 - Proposed Collection; 60-Day Comment Request: Incident HIV/Hepatitis B Virus Infections in South...

Science.gov (United States)

2013-11-08

... Comment Request: Incident HIV/ Hepatitis B Virus Infections in South African Blood Donors: Behavioral Risk... Collection: Incident HIV/Hepatitis B virus (HBV) infections in South African blood donors: Behavioral risk... (either antibody or antigen detection tests) to screen blood donors for HIV and Hepatitis-B Virus (HBV...

Interferon alpha inhibits replication of a live-attenuated porcine reproductive and respiratory syndrome virus vaccine preventing development of an adaptive immune response in swine.

Science.gov (United States)

Brockmeier, Susan L; Loving, Crystal L; Eberle, Kirsten C; Hau, Samantha J; Buckley, Alexandra; Van Geelen, Albert; Montiel, Nestor A; Nicholson, Tracy; Lager, Kelly M

2017-12-01

Type I interferons, such as interferon alpha (IFN-α), contribute to innate antiviral immunity by promoting production of antiviral mediators and are also involved in promoting an adaptive immune response. Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most devastating and costly viruses to the swine industry world-wide and has been shown to induce a meager IFN-α response. Previously we administered porcine IFN-α using a replication-defective adenovirus vector (Ad5-IFN-α) at the time of challenge with virulent PRRSV and demonstrated an increase in the number of virus-specific IFNγ secreting cells, indicating that the presence of IFN-α at the time of infection can alter the adaptive immune responses to PRRSV. In the current experiment, we explored the use of IFN-α as an adjuvant administered with live-attenuated PRRSV vaccine as a method to enhance immune response to the vaccine. Unlike the previous studies with fully virulent virus, one injection of the Ad5-IFN-α abolished replication of the vaccine virus and as a result there was no detectible adaptive immune response. Although IFN-α did not have the desired adjuvant effect, the results further highlight the use of IFN-α as a treatment for PRRSV infection. Published by Elsevier B.V.

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.

PB2 mutations D701N and S714R promote adaptation of an influenza H5N1 virus to a mammalian host.

Science.gov (United States)

Czudai-Matwich, Volker; Otte, Anna; Matrosovich, Mikhail; Gabriel, Gülsah; Klenk, Hans-Dieter

2014-08-01

Mutation D701N in the PB2 protein is known to play a prominent role in the adaptation of avian influenza A viruses to mammalian hosts. In contrast, little is known about the nearby mutations S714I and S714R, which have been observed in some avian influenza viruses highly pathogenic for mammals. We have generated recombinant H5N1 viruses with PB2 displaying the avian signature 701D or the mammalian signature 701N and serine, isoleucine, and arginine at position 714 and compared them for polymerase activity and virus growth in avian and mammalian cells, as well as for pathogenicity in mice. Mutation D701N led to an increase in polymerase activity and replication efficiency in mammalian cells and in mouse pathogenicity, and this increase was significantly enhanced when mutation D701N was combined with mutation S714R. Stimulation by mutation S714I was less distinct. These observations indicate that PB2 mutation S714R, in combination with the mammalian signature at position 701, has the potential to promote the adaptation of an H5N1 virus to a mammalian host. Influenza A/H5N1 viruses are avian pathogens that have pandemic potential, since they are spread over large parts of Asia, Africa, and Europe and are occasionally transmitted to humans. It is therefore of high scientific interest to understand the mechanisms that determine the host specificity and pathogenicity of these viruses. It is well known that the PB2 subunit of the viral polymerase is an important host range determinant and that PB2 mutation D701N plays an important role in virus adaptation to mammalian cells. In the present study, we show that mutation S714R is also involved in adaptation and that it cooperates with D701N in exposing a nuclear localization signal that mediates importin-α binding and entry of PB2 into the nucleus, where virus replication and transcription take place. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Positively charged residues at the five-fold symmetry axis of cell culture-adapted foot-and-mouth disease virus permit novel receptor interactions.

Science.gov (United States)

Berryman, Stephen; Clark, Stuart; Kakker, Naresh K; Silk, Rhiannon; Seago, Julian; Wadsworth, Jemma; Chamberlain, Kyle; Knowles, Nick J; Jackson, Terry

2013-08-01

Field isolates of foot-and-mouth disease virus (FMDV) have a restricted cell tropism which is limited by the need for certain RGD-dependent integrin receptors. In contrast, cell culture-adapted viruses use heparan sulfate (HS) or other unidentified molecules as receptors to initiate infection. Here, we report several novel findings resulting from cell culture adaptation of FMDV. In cell culture, a virus with the capsid of the A/Turkey/2/2006 field isolate gained the ability to infect CHO and HS-deficient CHO cells as a result of a single glutamine (Q)-to-lysine (K) substitution at VP1-110 (VP1-(Q)110(K)). Using site-directed mutagenesis, the introduction of lysine at this same site also resulted in an acquired ability to infect CHO cells by type O and Asia-1 FMDV. However, this ability appeared to require a second positively charged residue at VP1-109. CHO cells express two RGD-binding integrins (α5β1 and αvβ5) that, although not used by FMDV, have the potential to be used as receptors; however, viruses with the VP1-(Q)110(K) substitution did not use these integrins. In contrast, the VP1-(Q)110(K) substitution appeared to result in enhanced interactions with αvβ6, which allowed a virus with KGE in place of the normal RGD integrin-binding motif to use αvβ6 as a receptor. Thus, our results confirmed the existence of nonintegrin, non-HS receptors for FMDV on CHO cells and revealed a novel, non-RGD-dependent use of αvβ6 as a receptor. The introduction of lysine at VP1-110 may allow for cell culture adaptation of FMDV by design, which may prove useful for vaccine manufacture when cell culture adaptation proves intractable.

Positively Charged Residues at the Five-Fold Symmetry Axis of Cell Culture-Adapted Foot-and-Mouth Disease Virus Permit Novel Receptor Interactions

Science.gov (United States)

Berryman, Stephen; Clark, Stuart; Kakker, Naresh K.; Silk, Rhiannon; Seago, Julian; Wadsworth, Jemma; Chamberlain, Kyle; Knowles, Nick J.

2013-01-01

Field isolates of foot-and-mouth disease virus (FMDV) have a restricted cell tropism which is limited by the need for certain RGD-dependent integrin receptors. In contrast, cell culture-adapted viruses use heparan sulfate (HS) or other unidentified molecules as receptors to initiate infection. Here, we report several novel findings resulting from cell culture adaptation of FMDV. In cell culture, a virus with the capsid of the A/Turkey/2/2006 field isolate gained the ability to infect CHO and HS-deficient CHO cells as a result of a single glutamine (Q)-to-lysine (K) substitution at VP1-110 (VP1-Q110K). Using site-directed mutagenesis, the introduction of lysine at this same site also resulted in an acquired ability to infect CHO cells by type O and Asia-1 FMDV. However, this ability appeared to require a second positively charged residue at VP1-109. CHO cells express two RGD-binding integrins (α5β1 and αvβ5) that, although not used by FMDV, have the potential to be used as receptors; however, viruses with the VP1-Q110K substitution did not use these integrins. In contrast, the VP1-Q110K substitution appeared to result in enhanced interactions with αvβ6, which allowed a virus with KGE in place of the normal RGD integrin-binding motif to use αvβ6 as a receptor. Thus, our results confirmed the existence of nonintegrin, non-HS receptors for FMDV on CHO cells and revealed a novel, non-RGD-dependent use of αvβ6 as a receptor. The introduction of lysine at VP1-110 may allow for cell culture adaptation of FMDV by design, which may prove useful for vaccine manufacture when cell culture adaptation proves intractable. PMID:23740982

Genotyping of African swine fever virus (ASFV) isolates associated ...

African Journals Online (AJOL)

Four of these viruses were isolated directly from serum samples. All the viruses were classified within the domesticpig cycle-associated p72 and p54 genotype IX which also includes viruses responsible for ASF outbreaks in Kenya in 2006 and 2007 and Uganda in 2003. To define virus relationships at higher resolution, ...

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

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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.

High throughput multiplex real time PCR assay for the simultaneous quantification of DNA and RNA viruses infecting cassava plants

OpenAIRE

Otti, Gerald; Bouvaine, Sophie; Kimata, Bernadetha; Mkamillo, Geoffrey; Kumar, Lava; Tomlins, Keith; Maruthi, M.N.

2016-01-01

Aims: To develop a multiplex TaqMan-based real-time PCR assay (qPCR) for the simultaneous detection and quantification of both RNA and DNA viruses affecting cassava (Manihot esculenta) in eastern Africa.\\ud \\ud Methods and Results: The diagnostic assay was developed for two RNA viruses; Cassava brown streak virus (CBSV) and Uganda cassava brown streak virus (UCBSV) and two predominant DNA viruses; African cassava mosaic virus (ACMV) and East African cassava mosaic virus (EACMV), which cause t...

Pathological manifestations of feline immunodeficiency virus (FIV) infection in wild African lions.

Science.gov (United States)

Roelke, Melody E; Brown, Meredith A; Troyer, Jennifer L; Winterbach, Hanlie; Winterbach, Christiaan; Hemson, Graham; Smith, Dahlem; Johnson, Randall C; Pecon-Slattery, Jill; Roca, Alfred L; Alexander, Kathleen A; Klein, Lin; Martelli, Paolo; Krishnasamy, Karthiyani; O'Brien, Stephen J

2009-07-20

Feline immunodeficiency virus (FIV) causes AIDS in the domestic cat (Felis catus) but has not been explicitly associated with AIDS pathology in any of the eight free-ranging species of Felidae that are endemic with circulating FIV strains. African lion (Panthera leo) populations are infected with lion-specific FIV strains (FIVple), yet there remains uncertainty about the degree to which FIV infection impacts their health. Reported CD4+ T-lymphocyte depletion in FIVple-infected lions and anecdotal reports of lion morbidity associated with FIV seroprevalence emphasize the concern as to whether FIVple is innocuous or pathogenic. Here we monitored clinical, biochemical, histological and serological parameters among FIVple-positive (N=47) as compared to FIVple-negative (N=17) lions anesthetized and sampled on multiple occasions between 1999 and 2006 in Botswana. Relative to uninfected lions, FIVple-infected lions displayed a significant elevation in the prevalence of AIDS-defining conditions: lymphadenopathy, gingivitis, tongue papillomas, dehydration, and poor coat condition, as well as displaying abnormal red blood cell parameters, depressed serum albumin, and elevated liver enzymes and gamma globulin. Spleen and lymph node biopsies from free-ranging FIVple-infected lions (N=9) revealed evidence of lymphoid depletion, the hallmark pathology documented in immunodeficiency virus infections of humans (HIV-1), macaques, and domestic cats. We conclude that over time FIVple infections in free-ranging lions can lead to adverse clinical, immunological, and pathological outcomes in some individuals that parallel sequelae caused by lentivirus infection in humans (HIV), Asian macaques (SIV) and domestic cats (FIVfca).

PATHOLOGICAL MANIFESTATIONS OF FELINE IMMUNODEFICIENCY VIRUS (FIV) INFECTION IN WILD AFRICAN LIONS

Science.gov (United States)

Roelke, Melody E.; Brown, Meredith A.; Troyer, Jennifer L.; Winterbach, Hanlie; Winterbach, Christiaan; Hemson, Graham; Smith, Dahlem; Johnson, Randall C.; Pecon-Slattery, Jill; Roca, Alfred L.; Alexander, Katherine; Klein, Lin; Martinelli, Paulo; Krishnasamu, Karthiuani; O'Brien, Stephen J.

2009-01-01

Feline immunodeficiency virus (FIV) causes AIDS in the domestic cat (Felis catus) but has not been explicitly associated with AIDS pathology in any of the eight free-ranging species of Felidae that are endemic with circulating FIV strains. African lion (Panthera leo) populations are infected with lion-specific FIV strains (FIVple), yet there remains uncertainty about the degree to which FIV infection impacts their health. Reported CD4+ T-lymphocyte depletion in FIVple infected lions and anecdotal reports of lion morbidity associated with FIV sero-prevalence emphasize the concern as to whether FIVple is innocuous or pathogenic. Here we monitored clinical, biochemical, histological and serological parameters among FIVple-positive (N=47) as compared to FIVple negative (N=17) lions anesthetized and sampled on multiple occasions between 1999 and 2006 in Botswana. Relative to uninfected lions, FIVple infected lions displayed a significant elevation in the prevalence of AIDS defining conditions: lymphandenopathy, gingivitis, tongue papillomas, dehydration, and poor coat condition, as well as displaying abnormal red blood cell parameters and elevated liver enzymes and serum proteins. Spleen and lymph node laparoscopic biopsies from free-ranging FIVple infected lions (N=8) revealed evidence of lymphoid depletion, the hallmark pathology documented in immunodefieciency virus infections of humans (HIV-1), macaques, and domestic cats. We conclude that over time FIVple infections in free-ranging lions can lead to adverse clinical, immunological, and pathological outcomes in some individuals that parallel sequelae caused by lentivirus infection in humans (HIV), Asian macaques (SIV) and domestic cats (FIVfca). PMID:19464039

The first joint congress of the South African Biochemical Society, South African Genetics Society and the South African Society for Microbiology at the University of the Witwatersrand, 29 June-4 July 1986

International Nuclear Information System (INIS)

1986-01-01

The South African Biochemical Society, South African Genetics Society and the South African Society for Microbiology held a joint congress at the University of the Witwatersrand from 29 June - 4 July 1986. The papers delivered cover subjects such as Molecular biology, Genetics, Biochemistry, Medical biochemistry, Physiology, Zoology and Isotope and radiation sciences. Different isotopes are used in labelling studies of enzymes, nutrition, metabolism, viruses, bacteria and other biological assays done in the fields of Biochenmistry, Genetics and Microbiology. This work contains only the abstracts of these papers

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

Directory of Open Access Journals (Sweden)

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.

Third wave of African swine fever infection in Armenia: Virus demonstrates the reduction of pathogenicity

Science.gov (United States)

Sargsyan, M. A.; Voskanyan, H. E.; Karalova, E. M.; Hakobyan, L. H.; Karalyan, Z. A.

2018-01-01

Aim: First cases of clinically uncommon African swine fever (ASF), caused by virus genotype II are described in this article. These cases occurred in Armenia, Tavush region, Dilijan municipality in 2011. The aim of this study was to identify and describe the new pathogenic forms of ASF in Armenia. Materials and Methods: The isolation and identification of ASF virus (ASFV) were carried out using conventional techniques. Clinical signs of infection were recorded daily. Gross anatomical pathology characteristics were observed during routine postmortem examinations. Blood and serum were obtained by puncture of the jugular vein using a vacutainer system. Results: The presence of ASFV DNA in the spleens was confirmed by polymerase chain reaction. Sequenced sections of p72 showed phylogenetic identity to genotype 2. The pathology exhibits unusual manifestations of the main disease. The unusual form of ASF demonstrates characteristics of a subacute form of the disease, with the possibility of conversion to a chronic form. Decreased lethality, low level of hemorrhages, and absence of severe pancytopenia in smears from spleen, lymph nodes, and blood are common features of the new form of ASF. Unlike severe thrombocytopenia in the typical ASF, the unusual form exhibited moderate or minor decrease of this feature. Despite a moderate decrease in hemadsorption titers, the unusual pattern of the disease was characterized by viremia and the presence of the virus in the visceral organs, including the brain. Conclusion: Our data allow assuming that new nosological form of ASF (genotype II) may present as a transitional form of the disease with the possibility of chronization. PMID:29479149

Third wave of African swine fever infection in Armenia: Virus demonstrates the reduction of pathogenicity

Directory of Open Access Journals (Sweden)

M. A. Sargsyan

2018-01-01

Full Text Available Aim: First cases of clinically uncommon African swine fever (ASF, caused by virus genotype II are described in this article. These cases occurred in Armenia, Tavush region, Dilijan municipality in 2011. The aim of this study was to identify and describe the new pathogenic forms of ASF in Armenia. Materials and Methods: The isolation and identification of ASF virus (ASFV were carried out using conventional techniques. Clinical signs of infection were recorded daily. Gross anatomical pathology characteristics were observed during routine postmortem examinations. Blood and serum were obtained by puncture of the jugular vein using a vacutainer system. Results: The presence of ASFV DNA in the spleens was confirmed by polymerase chain reaction. Sequenced sections of p72 showed phylogenetic identity to genotype 2. The pathology exhibits unusual manifestations of the main disease. The unusual form of ASF demonstrates characteristics of a subacute form of the disease, with the possibility of conversion to a chronic form. Decreased lethality, low level of hemorrhages, and absence of severe pancytopenia in smears from spleen, lymph nodes, and blood are common features of the new form of ASF. Unlike severe thrombocytopenia in the typical ASF, the unusual form exhibited moderate or minor decrease of this feature. Despite a moderate decrease in hemadsorption titers, the unusual pattern of the disease was characterized by viremia and the presence of the virus in the visceral organs, including the brain. Conclusion: Our data allow assuming that new nosological form of ASF (genotype II may present as a transitional form of the disease with the possibility of chronization.

Hamster-Adapted Sin Nombre Virus Causes Disseminated Infection and Efficiently Replicates in Pulmonary Endothelial Cells without Signs of Disease

OpenAIRE

Safronetz, David; Prescott, Joseph; Haddock, Elaine; Scott, Dana P.; Feldmann, Heinz; Ebihara, Hideki

2013-01-01

To date, a laboratory animal model for the study of Sin Nombre virus (SNV) infection or associated disease has not been described. Unlike infection with Andes virus, which causes lethal hantavirus pulmonary syndrome (HPS)-like disease in hamsters, SNV infection is short-lived, with no viremia and little dissemination. Here we investigated the effect of passaging SNV in hamsters. We found that a host-adapted SNV achieves prolonged and disseminated infection in hamsters, including efficient rep...

Identification of adaptive mutations in the influenza A virus non-structural 1 gene that increase cytoplasmic localization and differentially regulate host gene expression.

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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.

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

Rapid acquisition adaptive amino acid substitutions involved in the virulence enhancement of an H1N2 avian influenza virus in mice.

Science.gov (United States)

Yu, Zhijun; Sun, Weiyang; Zhang, Xinghai; Cheng, Kaihui; Zhao, Chuqi; Xia, Xianzhu; Gao, Yuwei

2017-08-01

Although H1N2 avian influenza virus (AIV) only infect birds, documented cases of swine infection with H1N2 influenza viruses suggest this subtype AIV may pose a potential threat to mammals. Here, we generated mouse-adapted variants of a H1N2 AIV to identify adaptive changes that increased virulence in mammals. MLD 50 of the variants were reduced >1000-fold compared to the parental virus. Variants displayed enhanced replication in vitro and in vivo, and replicate in extrapulmonary organs. These data show that enhanced replication capacity and expanded tissue tropism may increase the virulence of H1N2 AIV in mice. Sequence analysis revealed multiple amino acid substitutions in the PB2 (L134H, I647L, and D701N), HA (G228S), and M1 (D231N) proteins. These results indicate that H1N2 AIV can rapidly acquire adaptive amino acid substitutions in mammalian hosts, and these amino acid substitutions collaboratively enhance the ability of H1N2 AIV to replicate and cause severe disease in mammals. Copyright © 2017 Elsevier B.V. All rights reserved.

The Demographic and Adaptive History of the African Green Monkey.

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Pfeifer, Susanne P

2017-05-01

Relatively little is known about the evolutionary history of the African green monkey (genus Chlorocebus) due to the lack of sampled polymorphism data from wild populations. Yet, this characterization of genetic diversity is not only critical for a better understanding of their own history, but also for human biomedical research given that they are one of the most widely used primate models. Here, I analyze the demographic and selective history of the African green monkey, utilizing one of the most comprehensive catalogs of wild genetic diversity to date, consisting of 1,795,643 autosomal single nucleotide polymorphisms in 25 individuals, representing all five major populations: C. a. aethiops, C. a. cynosurus, C. a. pygerythrus, C. a. sabaeus, and C. a tantalus. Assuming a mutation rate of 5.9 × 10-9 per base pair per generation and a generation time of 8.5 years, divergence time estimates range from 523 to 621 kya for the basal split of C. a. aethiops from the other four populations. Importantly, the resulting tree characterizing the relationship and split-times between these populations differs significantly from that presented in the original genome paper, owing to their neglect of within-population variation when calculating between population-divergence. In addition, I find that the demographic history of all five populations is well explained by a model of population fragmentation and isolation, rather than novel colonization events. Finally, utilizing these demographic models as a null, I investigate the selective history of the populations, identifying candidate regions potentially related to adaptation in response to pathogen exposure. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

[The present epidemiological status of African swine fever].

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Hess, G

1986-01-01

At present, African swine fever (ASF) persists as an enzootic infection both on the African continent and in Europe (Portugal, Spain, and Sardinia). The recent outbreaks of ASF in Belgium and in the Netherlands have again demonstrated the threat of this disease to the swine population in Germany. The main reasons for this threat are the great tenacity of this virus and its stability in meat and meat products together with an immense tourism into these enzootic areas. Epizootiological peculiarities, such as virus replication in ticks and inapparent infections in wild boars are the reason why eradication of the disease has failed so far, especially when pigs are allowed to roam the countryside.

Molecular Genetic Analysis of Orf Virus: A Poxvirus That Has Adapted to Skin

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Stephen B. Fleming

2015-03-01

Full Text Available Orf virus is the type species of the Parapoxvirus genus of the family Poxviridae. It induces acute pustular skin lesions in sheep and goats and is transmissible to humans. The genome is G+C rich, 138 kbp and encodes 132 genes. It shares many essential genes with vaccinia virus that are required for survival but encodes a number of unique factors that allow it to replicate in the highly specific immune environment of skin. Phylogenetic analysis suggests that both viral interleukin-10 and vascular endothelial growth factor genes have been “captured” from their host during the evolution of the parapoxviruses. Genes such as a chemokine binding protein and a protein that binds granulocyte-macrophage colony-stimulating factor and interleukin-2 appear to have evolved from a common poxvirus ancestral gene while three parapoxvirus nuclear factor (NF-κB signalling pathway inhibitors have no homology to other known NF-κB inhibitors. A homologue of an anaphase-promoting complex subunit that is believed to manipulate the cell cycle and enhance viral DNA synthesis appears to be a specific adaptation for viral-replication in keratinocytes. The review focuses on the unique genes of orf virus, discusses their evolutionary origins and their role in allowing viral-replication in the skin epidermis.

Molecular Genetic Analysis of Orf Virus: A Poxvirus That Has Adapted to Skin

Science.gov (United States)

Fleming, Stephen B.; Wise, Lyn M.; Mercer, Andrew A.

2015-01-01

Orf virus is the type species of the Parapoxvirus genus of the family Poxviridae. It induces acute pustular skin lesions in sheep and goats and is transmissible to humans. The genome is G+C rich, 138 kbp and encodes 132 genes. It shares many essential genes with vaccinia virus that are required for survival but encodes a number of unique factors that allow it to replicate in the highly specific immune environment of skin. Phylogenetic analysis suggests that both viral interleukin-10 and vascular endothelial growth factor genes have been “captured” from their host during the evolution of the parapoxviruses. Genes such as a chemokine binding protein and a protein that binds granulocyte-macrophage colony-stimulating factor and interleukin-2 appear to have evolved from a common poxvirus ancestral gene while three parapoxvirus nuclear factor (NF)-κB signalling pathway inhibitors have no homology to other known NF-κB inhibitors. A homologue of an anaphase-promoting complex subunit that is believed to manipulate the cell cycle and enhance viral DNA synthesis appears to be a specific adaptation for viral-replication in keratinocytes. The review focuses on the unique genes of orf virus, discusses their evolutionary origins and their role in allowing viral-replication in the skin epidermis. PMID:25807056

Occult hepatitis B virus coinfection in HIV-positive African migrants to the UK: a point prevalence study.

Science.gov (United States)

Chadwick, D; Doyle, T; Ellis, S; Price, D; Abbas, I; Valappil, M; Geretti, A M

2014-03-01

Occult (surface antigen-negative/DNA-positive) hepatitis B virus (HBV) infection is common in areas of the world where HBV is endemic. The main objectives of this study were to determine the prevalence of occult HBV infection in HIV-infected African migrants to the UK and to determine factors associated with occult coinfection. This anonymized point-prevalence study identified Africans attending three HIV clinics, focussing on patients naïve to antiretroviral therapy (ART). Stored blood samples were tested for HBV DNA. Prevalence was calculated in the entire cohort, as well as in subpopulations. Risk factors for occult HBV coinfection were identified using logistic regression analysis. Among 335 HIV-positive African migrants, the prevalence of occult HBV coinfection was 4.5% [95% confidence interval (CI) 2.8-7.4%] overall, and 6.5% (95% CI 3.9-10.6%) and 0.8% (95% CI 0.2-4.6%) in ART-naïve and ART-experienced patients, respectively. Among ART-naïve anti-HBV core (anti-HBc)-positive patients, the prevalence was 16.4% (95% CI 8.3-25.6%). The strongest predictor of occult coinfection was anti-HBc positivity [odds ratio (OR) 7.4; 95% CI 2.0-27.6]. Median HBV DNA and ALT levels were 54 IU/mL [interquartile range (IQR) 33-513 IU/mL] and 22 U/L (IQR 13-27 U/L), respectively. Occult HBV coinfection remains under-diagnosed in African HIV-infected patients in the UK. Given the range of HBV DNA levels observed, further studies are warranted to determine its clinical significance and to guide screening strategies and ART selection in these patients. © 2013 British HIV Association.

Combined therapy of interferon plus ribavirin promotes multiple adaptive solutions in hepatitis C virus.

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Cuevas, José M; Torres-Puente, Manuela; Jiménez-Hernández, Nuria; Bracho, María A; García-Robles, Inmaculada; Carnicer, Fernando; Olmo, Juan Del; Ortega, Enrique; González-Candelas, Fernando; Moya, Andrés

2009-04-01

Hepatitis C virus (HCV) presents several regions involved potentially in evading antiviral treatment and host immune system. Two regions, known as PKR-BD and V3 domains, have been proposed to be involved in resistance to interferon. Additionally, hypervariable regions in the envelope E2 glycoprotein are also good candidates to participate in evasion from the immune system. In this study, we have used a cohort of 22 non-responder patients to combined therapy (interferon alpha-2a plus ribavirin) for which samples obtained just before initiation of therapy and after 6 or/and 12 months of treatment were available. A range of 25-100 clones per patient, genome region and time sample were obtained. The predominant amino acid sequences for each time sample and patient were determined. Next, the sequences of the PKR-BD and V3 domains and the hypervariable regions from different time samples were compared for each patient. The highest levels of variability were detected at the three hypervariable regions of the E2 protein and, to a lower extent, at the V3 domain of the NS5A protein. However, no clear patterns of adaptation to the host immune system or to antiviral treatment were detected. In summary, although high levels of variability are correlated to viral adaptive response, antiviral treatment does not seem to promote convergent adaptive changes. Consequently, other regions must be involved in evasion strategies likely based on a combination of multiple mechanisms, in which pools of changes along the HCV genome could confer viruses the ability to overcome strong selective pressures. (c) 2009 Wiley-Liss, Inc.

Virus surveys of Capsicum spp. in the Republic of Benin reveal the prevalence of pepper vein yellows virus and the identification of a previously uncharacterised polerovirus species.

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Afouda, Leonard; Kone, Daouda; Zinsou, Valerien; Dossou, Laurence; Kenyon, Lawrence; Winter, Stephan; Knierim, Dennis

2017-06-01

Surveys were conducted in 2014 and 2015 in Southern and Northern Benin, respectively, to identify the viruses infecting peppers (Capsicum spp.). The samples were screened by ELISA for cucumber mosaic virus (CMV), pepper veinal mottle virus (PVMV), potato virus Y (PVY) and tomato yellow leaf curl virus (TYLCV). A generic reverse transcription PCR (RT-PCR) was used to test for the presence of poleroviruses. ELISA tests confirmed the prevalence of all viruses, while the RT-PCR detected pepper vein yellows virus (PeVYV) which is reported for the first time in Benin. A further, divergent polerovirus isolate was detected from a single pepper sample originating from southern Benin. Screening of samples collected from solanaceous plants during virus surveys in Mali (conducted in 2009) also detected this divergent polerovirus isolate in two samples from African eggplants. The complete genome sequence was obtained from the Mali isolate using transcriptome sequencing and by conventional Sanger sequencing of overlapping RT-PCR products. Based on the sequence characteristics of this isolate we propose a new polerovirus species, African eggplant yellowing virus (AeYV).

The novel human influenza A(H7N9) virus is naturally adapted to efficient growth in human lung tissue.

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Knepper, Jessica; Schierhorn, Kristina L; Becher, Anne; Budt, Matthias; Tönnies, Mario; Bauer, Torsten T; Schneider, Paul; Neudecker, Jens; Rückert, Jens C; Gruber, Achim D; Suttorp, Norbert; Schweiger, Brunhilde; Hippenstiel, Stefan; Hocke, Andreas C; Wolff, Thorsten

2013-10-08

A novel influenza A virus (IAV) of the H7N9 subtype has been isolated from severely diseased patients with pneumonia and acute respiratory distress syndrome and, apparently, from healthy poultry in March 2013 in Eastern China. We evaluated replication, tropism, and cytokine induction of the A/Anhui/1/2013 (H7N9) virus isolated from a fatal human infection and two low-pathogenic avian H7 subtype viruses in a human lung organ culture system mimicking infection of the lower respiratory tract. The A(H7N9) patient isolate replicated similarly well as a seasonal IAV in explanted human lung tissue, whereas avian H7 subtype viruses propagated poorly. Interestingly, the avian H7 strains provoked a strong antiviral type I interferon (IFN-I) response, whereas the A(H7N9) virus induced only low IFN levels. Nevertheless, all viruses analyzed were detected predominantly in type II pneumocytes, indicating that the A(H7N9) virus does not differ in its cellular tropism from other avian or human influenza viruses. Tissue culture-based studies suggested that the low induction of the IFN-β promoter correlated with an efficient suppression by the viral NS1 protein. These findings demonstrate that the zoonotic A(H7N9) virus is unusually well adapted to efficient propagation in human alveolar tissue, which most likely contributes to the severity of lower respiratory tract disease seen in many patients. Humans are usually not infected by avian influenza A viruses (IAV), but this large group of viruses contributes to the emergence of human pandemic strains. Transmission of virulent avian IAV to humans is therefore an alarming event that requires assessment of the biology as well as pathogenic and pandemic potentials of the viruses in clinically relevant models. Here, we demonstrate that an early virus isolate from the recent A(H7N9) outbreak in Eastern China replicated as efficiently as human-adapted IAV in explanted human lung tissue, whereas avian H7 subtype viruses were unable to

Globin haplotypes of human T-cell lymphotropic virus type I-infected individuals in Salvador, Bahia, Brazil, suggest a post-Columbian African origin of this virus.

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Alcantara, Luiz Carlos; Van Dooren, Sonia; Gonçalves, Marilda Souza; Kashima, Simone; Costa, Maria Cristina Ramos; Santos, Fred Luciano Neves; Bittencourt, Achilea Lisboa; Dourado, Inês; Filho, Antonio Andrade; Covas, Dimas Tadeu; Vandamme, Anne-Mieke; Galvão-Castro, Bernardo

2003-08-01

The city of Salvador, Bahia, Brazil, has sociodemographic characteristics similar to some African cities. Up to now, it has had the highest prevalence of human T-cell lymphotropic virus type I (HTLV-I) infection (1.74%) in the country. To investigate which strains of HTLV-I are circulating in Salvador, we studied isolates from 82 patients infected with HTLV-I: 19 from the general population, 21 from pregnant women, 16 from intravenous drug users, and 26 from patients and their family attending a neurologic clinic. Phylogenetic analysis from part of the LTR fragments showed that most of these isolates belonged to the Transcontinental subgroup of the Cosmopolitan subtype (HTLV-Ia). Only one sample from a pregnant woman was closely related to the Japanese subgroup, suggesting recent introduction of a Japanese HTLV-I lineage into Salvador. betaA-Globin haplotypes were examined in 34 infected individuals and found to be atypical, confirming the racial heterogeneity of this population. A total of 20 chromosomes were characterized as Central African Republic (CAR) haplotype (29.4%), 31 (45.6%) were characterized as Benin (BEN) haplotype, and 17 (25%) were characterized as Senegal (SEN) haplotype. Five patients' genotypes (14.7%) were CAR/CAR; 10 (29,4%), BEN/BEN; 9 (26.5%), CAR/BEN; 2 (5.9%), BEN/SEN; and 7 (20.6%), SEN/SEN. One patient's genotype (2.9%) was CAR/SEN. The betaA-globin haplotype distribution in Salvador is unusual compared with other Brazilian states. Our data support the hypothesis of multiple post-Columbian introductions of African HTLV-Ia strains in Salvador, Bahia, Brazil.

Suramin is a potent inhibitor of Chikungunya and Ebola virus cell entry.

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Henß, Lisa; Beck, Simon; Weidner, Tatjana; Biedenkopf, Nadine; Sliva, Katja; Weber, Christopher; Becker, Stephan; Schnierle, Barbara S

2016-08-31

Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that causes high fever, rash, and recurrent arthritis in humans. It has efficiently adapted to Aedes albopictus, which also inhabits temperate regions and currently causes large outbreaks in the Caribbean and Latin America. Ebola virus (EBOV) is a member of the filovirus family. It causes the Ebola virus disease (EDV), formerly known as Ebola hemorrhagic fever in humans and has a mortality rate of up to 70 %. The last outbreak in Western Africa was the largest in history and has caused approximately 25,000 cases and 10,000 deaths. For both viral infections no specific treatment or licensed vaccine is currently available. The bis-hexasulfonated naphthylurea, suramin, is used as a treatment for trypanosome-caused African river blindness. As a competitive inhibitor of heparin, suramin has been described to have anti-viral activity. We tested the activity of suramin during CHIKV or Ebola virus infection, using CHIKV and Ebola envelope glycoprotein pseudotyped lentiviral vectors and wild-type CHIKV and Ebola virus. Suramin efficiently inhibited CHIKV and Ebola envelope-mediated gene transfer while vesicular stomatitis virus G protein pseudotyped vectors were only marginally affected. In addition, suramin was able to inhibit wild-type CHIKV and Ebola virus replication in vitro. Inhibition occurred at early time points during CHIKV infection. Suramin, also known as Germanin or Bayer-205, is a market-authorized drug, however shows significant side effects, which probably prevents its use as a CHIKV drug, but due to the high lethality of Ebola virus infections, suramin might be valuable against Ebola infections.

Comparison of G protein sequences of South African street rabies viruses showing distinct progression of the disease in a mouse model of experimental rabies.

Science.gov (United States)

Seo, Wonhyo; Servat, Alexandre; Cliquet, Florence; Akinbowale, Jenkins; Prehaud, Christophe; Lafon, Monique; Sabeta, Claude

Rabies is a fatal zoonotic disease and infections generally lead to a fatal encephalomyelitis in both humans and animals. In South Africa, domestic (dogs) and the wildlife (yellow mongoose) host species maintain the canid and mongoose rabies variants respectively. In this study, pathogenicity differences of South African canid and mongoose rabies viruses were investigated in a murine model, by assessing the progression of clinical signs and survivorship. Comparison of glycoprotein gene sequences revealed amino acid differences that may underpin the observed pathogenicity differences. Cumulatively, our results suggest that the canid rabies virus may be more neurovirulent in mice than the mongoose rabies variant. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

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

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Wekesa, Sabenzia Nabalayo; Sangula, Abraham Kiprotich; Belsham, Graham J; Tjornehoj, Kirsten; Muwanika, Vincent B; Gakuya, Francis; Mijele, Dominic; Siegismund, Hans Redlef

2015-02-03

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 intermingle with livestock in Kenya, yet earlier studies have focused on FMD in the domestic livestock, hence the contribution of buffalo to disease in livestock is largely unknown. This study analysed 47 epithelia collected from FMD outbreaks in Kenyan cattle between 2008 and 2012, and 102 probang and serum samples collected from buffalo in three different Kenyan ecosystems; Maasai-Mara (MME) (n = 40), Tsavo (TSE) (n = 33), and Meru (ME) (n = 29). Antibodies against FMDV non-structural proteins were found in 65 of 102 (64%) sera from buffalo with 44/102 and 53/102 also having neutralising antibodies directed against FMDV SAT 1 and SAT 2, respectively. FMDV RNA was detected in 42% of the buffalo probang samples by RT-qPCR (Cycle Threshold (Ct) ≤32). Two buffalo probang samples were positive by VI and were identified as FMDV SAT 1 and SAT 2 by Ag-ELISA, while the latter assay detected serotypes O (1), A (20), SAT 1 (7) and SAT 2 (19) in the 47 cattle epithelia. VP1 coding sequences were generated for two buffalo and 21 cattle samples. Phylogenetic analyses revealed SAT 1 and SAT 2 virus lineages within buffalo that were distinct from those detected in cattle. We found that FMDV serotypes O, A, SAT 1 and SAT 2 were circulating among cattle in Kenya and cause disease, but only SAT 1 and SAT 2 viruses were successfully isolated from clinically normal buffalo. The buffalo isolates were genetically distinct from isolates obtained from cattle. Control efforts should focus primarily on reducing FMDV circulation among livestock and limiting interaction with buffalo. Comprehensive studies incorporating additional buffalo viruses are recommended.

Genetic characterization of an adapted pandemic 2009 H1N1 influenza virus that reveals improved replication rates in human lung epithelial cells

International Nuclear Information System (INIS)

Wörmann, Xenia; Lesch, Markus; Welke, Robert-William; Okonechnikov, Konstantin; Abdurishid, Mirshat; Sieben, Christian; Geissner, Andreas; Brinkmann, Volker; Kastner, Markus; Karner, Andreas; Zhu, Rong; Hinterdorfer, Peter; Anish, Chakkumkal; Seeberger, Peter H.; Herrmann, Andreas

2016-01-01

The 2009 influenza pandemic originated from a swine-origin H1N1 virus, which, although less pathogenic than anticipated, may acquire additional virulence-associated mutations in the future. To estimate the potential risk, we sequentially passaged the isolate A/Hamburg/04/2009 in A549 human lung epithelial cells. After passage 6, we observed a 100-fold increased replication rate. High-throughput sequencing of viral gene segments identified five dominant mutations, whose contribution to the enhanced growth was analyzed by reverse genetics. The increased replication rate was pinpointed to two mutations within the hemagglutinin (HA) gene segment (HA_1 D130E, HA_2 I91L), near the receptor binding site and the stem domain. The adapted virus also replicated more efficiently in mice in vivo. Enhanced replication rate correlated with increased fusion pH of the HA protein and a decrease in receptor affinity. Our data might be relevant for surveillance of pre-pandemic strains and development of high titer cell culture strains for vaccine production. - Highlights: • We observed a spontaneous mutation of a 2009-pandemic H1N1 influenza virus in vitro. • The adaptation led to a 100-fold rise in replication rate in human A549 cells. • Adaptation was caused by two mutations in the HA gene segment. • Adaptation correlates with increased fusion pH and decreased receptor affinity.

Genetic characterization of an adapted pandemic 2009 H1N1 influenza virus that reveals improved replication rates in human lung epithelial cells

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Wörmann, Xenia [Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin (Germany); Lesch, Markus [Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin (Germany); Steinbeis Innovation gGmbH, Center for Systems Biomedicine, Falkensee (Germany); Welke, Robert-William [Department of Biology, Molecular Biophysics, IRI Life Sciences, Humboldt-Universität zu Berlin (Germany); Okonechnikov, Konstantin; Abdurishid, Mirshat [Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin (Germany); Sieben, Christian [Department of Biology, Molecular Biophysics, IRI Life Sciences, Humboldt-Universität zu Berlin (Germany); Geissner, Andreas [Department for Biomolecular Systems, Max Planck Institute for Colloids and Interfaces, Potsdam (Germany); Institute of Chemistry and Biochemistry, Free University, Berlin (Germany); Brinkmann, Volker [Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin (Germany); Kastner, Markus [Institute for Biophysics, Johannes Kepler University, Linz (Austria); Karner, Andreas [Center for Advanced Bioanalysis GmbH (CBL), Linz (Austria); Zhu, Rong; Hinterdorfer, Peter [Institute for Biophysics, Johannes Kepler University, Linz (Austria); Anish, Chakkumkal [Department for Biomolecular Systems, Max Planck Institute for Colloids and Interfaces, Potsdam (Germany); Seeberger, Peter H. [Department for Biomolecular Systems, Max Planck Institute for Colloids and Interfaces, Potsdam (Germany); Institute of Chemistry and Biochemistry, Free University, Berlin (Germany); Herrmann, Andreas [Department of Biology, Molecular Biophysics, IRI Life Sciences, Humboldt-Universität zu Berlin (Germany); and others

2016-05-15

The 2009 influenza pandemic originated from a swine-origin H1N1 virus, which, although less pathogenic than anticipated, may acquire additional virulence-associated mutations in the future. To estimate the potential risk, we sequentially passaged the isolate A/Hamburg/04/2009 in A549 human lung epithelial cells. After passage 6, we observed a 100-fold increased replication rate. High-throughput sequencing of viral gene segments identified five dominant mutations, whose contribution to the enhanced growth was analyzed by reverse genetics. The increased replication rate was pinpointed to two mutations within the hemagglutinin (HA) gene segment (HA{sub 1} D130E, HA{sub 2} I91L), near the receptor binding site and the stem domain. The adapted virus also replicated more efficiently in mice in vivo. Enhanced replication rate correlated with increased fusion pH of the HA protein and a decrease in receptor affinity. Our data might be relevant for surveillance of pre-pandemic strains and development of high titer cell culture strains for vaccine production. - Highlights: • We observed a spontaneous mutation of a 2009-pandemic H1N1 influenza virus in vitro. • The adaptation led to a 100-fold rise in replication rate in human A549 cells. • Adaptation was caused by two mutations in the HA gene segment. • Adaptation correlates with increased fusion pH and decreased receptor affinity.

Virus genomes reveal factors that spread and sustained the Ebola epidemic

DEFF Research Database (Denmark)

Dudas, Gytis; Carvalho, Luiz Max; Bedford, Trevor

2017-01-01

The 2013-2016 West African epidemic caused by the Ebola virus was of unprecedented magnitude, duration and impact. Here we reconstruct the dispersal, proliferation and decline of Ebola virus throughout the region by analysing 1,610 Ebola virus genomes, which represent over 5% of the known cases. ...

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

2009-06-01

Full Text Available 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.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.Our data suggest that glycoprotein cleavage by S1P is a promising target for the development of novel anti-arenaviral strategies.

Zika Virus Strains Potentially Display Different Infectious Profiles in Human Neural Cells

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Yannick Simonin

2016-10-01

Full Text Available The recent Zika virus (ZIKV epidemic has highlighted the poor knowledge on its physiopathology. Recent studies showed that ZIKV of the Asian lineage, responsible for this international outbreak, causes neuropathology in vitro and in vivo. However, two African lineages exist and the virus is currently found circulating in Africa. The original African strain was also suggested to be neurovirulent but its laboratory usage has been criticized due to its multiple passages. In this study, we compared the French Polynesian (Asian ZIKV strain to an African strain isolated in Central African Republic and show a difference in infectivity and cellular response between both strains in human neural stem cells and astrocytes. Consistently, this African strain led to a higher infection rate and viral production, as well as stronger cell death and anti-viral response. Our results highlight the need to better characterize the physiopathology and predict neurological impairment associated with African ZIKV.

Transmissibility of the monkeypox virus clades via respiratory transmission: investigation using the prairie dog-monkeypox virus challenge system.

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Christina L Hutson

Full Text Available Monkeypox virus (MPXV is endemic within Africa where it sporadically is reported to cause outbreaks of human disease. In 2003, an outbreak of human MPXV occurred in the US after the importation of infected African rodents. Since the eradication of smallpox (caused by an orthopoxvirus (OPXV related to MPXV and cessation of routine smallpox vaccination (with the live OPXV vaccinia, there is an increasing population of people susceptible to OPXV diseases. Previous studies have shown that the prairie dog MPXV model is a functional animal model for the study of systemic human OPXV illness. Studies with this model have demonstrated that infected animals are able to transmit the virus to naive animals through multiple routes of exposure causing subsequent infection, but were not able to prove that infected animals could transmit the virus exclusively via the respiratory route. Herein we used the model system to evaluate the hypothesis that the Congo Basin clade of MPXV is more easily transmitted, via respiratory route, than the West African clade. Using a small number of test animals, we show that transmission of viruses from each of the MPXV clade was minimal via respiratory transmission. However, transmissibility of the Congo Basin clade was slightly greater than West African MXPV clade (16.7% and 0% respectively. Based on these findings, respiratory transmission appears to be less efficient than those of previous studies assessing contact as a mechanism of transmission within the prairie dog MPXV animal model.

A genomic portrait of haplotype diversity and signatures of selection in indigenous southern African populations.

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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.

A genomic portrait of haplotype diversity and signatures of selection in indigenous southern African populations.

Science.gov (United States)

Chimusa, Emile R; Meintjies, Ayton; Tchanga, Milaine; Mulder, Nicola; Seoighe, Cathal; Seioghe, Cathal; Soodyall, Himla; Ramesar, Rajkumar

2015-03-01

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.

Virus genomes reveal factors that spread and sustained the Ebola epidemic

DEFF Research Database (Denmark)

Dudas, Gytis; Carvalho, Luiz Max; Bedford, Trevor

2017-01-01

The 2013-2016 West African epidemic caused by the Ebola virus was of unprecedented magnitude, duration and impact. Here we reconstruct the dispersal, proliferation and decline of Ebola virus throughout the region by analysing 1,610 Ebola virus genomes, which represent over 5% of the known cases. We...

Physiological adaptation to the humid tropics with special reference to the West African Dwarf (WAD) goat.

Science.gov (United States)

Daramola, J O; Adeloye, A A

2009-10-01

West African Dwarf (WAD) goats are widely distributed in the subhumid and humid zones of Africa but are particularly associated with less favourable environments. Adaptive features such as feeding behaviour, efficiency of feed use and disease tolerance enable WAD goats to thrive on natural resources left untouched by other domestic ruminants. In marginal environments this goat remains the only domestic species that is able to survive. Among its physiological features small body size and low metabolic requirements are important traits that enable the animal to minimize its requirements in area or season where food sources are limited in quality and quantity. Specialized feeding behaviour and an efficient digestive system enable the animal to maximize food intake. Coat colour plays an important role in the evolved adaptation of this goat type. Reproductive fitness as manifested by prolific breeding is a major factor of adaptation. Defence mechanisms against infectious agents enable this type to thrive well in the hot humid tropics. The mechanisms involved in the regulation of these physiological functions of WAD goat are discussed. An understanding of these mechanisms could result in the development of improved techniques for enhancing goat productivity in humid environments.

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. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

Ganjam virus/Nairobi sheep disease virus induces a pro-inflammatory response in infected sheep

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bin Tarif Abid

2012-10-01

Full Text Available Abstract Partly due to climate change, and partly due to changes of human habitat occupation, the impact of tick-borne viruses is increasing. Nairobi sheep disease virus (NSDV and Ganjam virus (GV are two names for the same virus, which causes disease in sheep and goats and is currently known to be circulating in India and East Africa. The virus is transmitted by ixodid ticks and causes a severe hemorrhagic disease. We have developed a real-time PCR assay for the virus genome and validated it in a pilot study of the pathogenicity induced by two different isolates of NSDV/GV. One isolate was highly adapted to tissue culture, grew in most cell lines tested, and was essentially apathogenic in sheep. The second isolate appeared to be poorly adapted to cell culture and retained pathogenicity in sheep. The real-time PCR assay for virus easily detected 4 copies or less of the viral genome, and allowed a quantitative measure of the virus in whole blood. Measurement of the changes in cytokine mRNAs showed similar changes to those observed in humans infected by the closely related virus Crimean Congo hemorrhagic fever virus.

Ganjam virus/Nairobi sheep disease virus induces a pro-inflammatory response in infected sheep.

Science.gov (United States)

Bin Tarif, Abid; Lasecka, Lidia; Holzer, Barbara; Baron, Michael D

2012-10-19

Partly due to climate change, and partly due to changes of human habitat occupation, the impact of tick-borne viruses is increasing. Nairobi sheep disease virus (NSDV) and Ganjam virus (GV) are two names for the same virus, which causes disease in sheep and goats and is currently known to be circulating in India and East Africa. The virus is transmitted by ixodid ticks and causes a severe hemorrhagic disease. We have developed a real-time PCR assay for the virus genome and validated it in a pilot study of the pathogenicity induced by two different isolates of NSDV/GV. One isolate was highly adapted to tissue culture, grew in most cell lines tested, and was essentially apathogenic in sheep. The second isolate appeared to be poorly adapted to cell culture and retained pathogenicity in sheep. The real-time PCR assay for virus easily detected 4 copies or less of the viral genome, and allowed a quantitative measure of the virus in whole blood. Measurement of the changes in cytokine mRNAs showed similar changes to those observed in humans infected by the closely related virus Crimean Congo hemorrhagic fever virus.

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

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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

Differential responses of Africanized and European honey bees (Apis mellifera) to viral replication following mechanical transmission or Varroa destructor parasitism.

Science.gov (United States)

Hamiduzzaman, Mollah Md; Guzman-Novoa, Ernesto; Goodwin, Paul H; Reyes-Quintana, Mariana; Koleoglu, Gun; Correa-Benítez, Adriana; Petukhova, Tatiana

2015-03-01

For the first time, adults and brood of Africanized and European honey bees (Apis mellifera) were compared for relative virus levels over 48 h following Varroa destructor parasitism or injection of V. destructor homogenate. Rates of increase of deformed wing virus (DWV) for Africanized versus European bees were temporarily lowered for 12h with parasitism and sustainably lowered over the entire experiment (48 h) with homogenate injection in adults. The rates were also temporarily lowered for 24h with parasitism but were not affected by homogenate injection in brood. Rates of increase of black queen cell virus (BQCV) for Africanized versus European bees were similar with parasitism but sustainably lowered over the entire experiment with homogenate injection in adults and were similar for parasitism and homogenate injection in brood. Analyses of sac brood bee virus and Israeli acute paralysis virus were limited as detection did not occur after both homogenate injection and parasitism treatment, or levels were not significantly higher than those following control buffer injection. Lower rates of replication of DWV and BQCV in Africanized bees shows that they may have greater viral resistance, at least early after treatment. Copyright © 2014 Elsevier Inc. All rights reserved.

Modular framework to assess the risk of African swine fever virus entry into the European Union.

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Mur, Lina; Martínez-López, Beatriz; Costard, Solenne; de la Torre, Ana; Jones, Bryony A; Martínez, Marta; Sánchez-Vizcaíno, Fernando; Muñoz, María Jesús; Pfeiffer, Dirk U; Sánchez-Vizcaíno, José Manuel; Wieland, Barbara

2014-07-03

The recent occurrence and spread of African swine fever (ASF) in Eastern Europe is perceived as a serious risk for the pig industry in the European Union (EU). In order to estimate the potential risk of ASF virus (ASFV) entering the EU, several pathways of introduction were previously assessed separately. The present work aimed to integrate five of these assessments (legal imports of pigs, legal imports of products, illegal imports of products, fomites associated with transport and wild boar movements) into a modular tool that facilitates the visualization and comprehension of the relative risk of ASFV introduction into the EU by each analyzed pathway. The framework's results indicate that 48% of EU countries are at relatively high risk (risk score 4 or 5 out of 5) for ASFV entry for at least one analyzed pathway. Four of these countries obtained the maximum risk score for one pathway: Bulgaria for legally imported products during the high risk period (HRP); Finland for wild boar; Slovenia and Sweden for legally imported pigs during the HRP. Distribution of risk considerably differed from one pathway to another; for some pathways, the risk was concentrated in a few countries (e.g., transport fomites), whereas other pathways incurred a high risk for 4 or 5 countries (legal pigs, illegal imports and wild boar). The modular framework, developed to estimate the risk of ASFV entry into the EU, is available in a public domain, and is a transparent, easy-to-interpret tool that can be updated and adapted if required. The model's results determine the EU countries at higher risk for each ASFV introduction route, and provide a useful basis to develop a global coordinated program to improve ASFV prevention in the EU.

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.

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.

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

International Nuclear Information System (INIS)

Hipp, Katharina; Rau, Peter; Schäfer, Benjamin; Gronenborn, Bruno; Jeske, Holger

2014-01-01

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

Flock-based surveillance for lowpathogenic avian influenza virus in ...

African Journals Online (AJOL)

Flock-based surveillance for lowpathogenic avian influenza virus in commercial breeders and layers, southwest Nigeria. ... African Journal of Infectious Diseases ... Background: Flock surveillance systems for avian influenza (AI) virus play a critical role in countries where vaccination is not practiced so as to establish the ...

Conducting health survey research in a deep rural South African community: challenges and adaptive strategies.

Science.gov (United States)

Casale, Marisa; Lane, Tyler; Sello, Lebo; Kuo, Caroline; Cluver, Lucie

2013-04-24

In many parts of the developing world, rural health requires focused policy attention, informed by reliable, representative health data. Yet there is surprisingly little published material to guide health researchers who face the unique set of hurdles associated with conducting field research in remote rural areas. In this paper we provide a detailed description of the key challenges encountered during health survey field research carried out in 2010 in a deep rural site in KwaZulu-Natal, South Africa. The aim of the field research was to collect data on the health of children aged 10 to 17 years old, and their primary adult caregivers, as part of a larger national health survey; the research was a collaboration between several South African and foreign universities, South African national government departments, and various NGO partners. In presenting each of the four fieldwork challenges encountered on this site, we describe the initial planning decisions made, the difficulties faced when implementing these in the field, and the adaptive strategies we used to respond to these challenges. We reflect on learnings of potential relevance for the research community. Our four key fieldwork challenges were scarce research capacity, staff relocation tensions, logistical constraints, and difficulties related to community buy-in. Addressing each of these obstacles required timely assessment of the situation and adaptation of field plans, in collaboration with our local NGO partner. Adaptive strategies included a greater use of local knowledge; the adoption of tribal authority boundaries as the smallest geopolitical units for sampling; a creative developmental approach to capacity building; and planned, on-going engagement with multiple community representatives. We argue that in order to maintain high scientific standards of research and manage to 'get the job done' on the ground, it is necessary to respond to fieldwork challenges that arise as a cohesive team, with timely

African Swine Fever Virus, Siberia, Russia, 2017.

Science.gov (United States)

Kolbasov, Denis; Titov, Ilya; Tsybanov, Sodnom; Gogin, Andrey; Malogolovkin, Alexander

2018-04-01

African swine fever (ASF) is arguably the most dangerous and emerging swine disease worldwide. ASF is a serious problem for the swine industry. The first case of ASF in Russia was reported in 2007. We report an outbreak of ASF in Siberia, Russia, in 2017.

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

sensitive than the conventional PCR recommended by the OIE. Linear range was ten logs from 2 × 101 to 2 × 1010. The assay is rapid with an amplification time just over 2 h. The development of this assay provides a useful tool for the specific diagnosis of ASF in statutory or emergency testing programs......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...

Zika virus infection: The resurgence of a neglected disease

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Tushar Kambale

2016-01-01

Full Text Available "Zika virus" (ZIKV is an enveloped, icosahedral virus and has a positive-sense, single-stranded RNA genome approximately 11 kb in length. Genetic studies have revealed three ZIKV lineages: East African, West African, and Asian. Serologic studies and virus isolations have demonstrated that the virus has a wide geographic distribution, spanning East and West Africa, the Americas, Indian subcontinent, and Southeast Asia. ZIKV can cause complications such as Guillain-Barré syndrome, meningitis, meningoencephalitis, and myelitis. During pregnancy ZIKV infection can lead to miscarriages and microcephaly, cerebral calcifications, macular neuroretinal atrophy, and loss of foveal reflex in the fetus. A clinically suspected case of infection with dengue negative result should be further tested for Flavivirus, including Zika. Immunofluorescence or enzyme-linked immunosorbent assay is used to detect specific IgM or IgG antibodies against ZIKV. In cases of positive ZIKV infection, symptomatic treatment should be given after excluding other condition such as dengue, malaria, and bacterial infections.

Amélioration de l'adaptation aux changements climatiques des ...

International Development Research Centre (IDRC) Digital Library (Canada)

Journal supplement features 10 years of West African health systems research. In the wake of the devastating Ebola virus outbreak in 2014, increased attention has been paid to West Africa's poorly functioning health systems. View moreJournal supplement features 10 years of West African health systems research ...

Fonds d'appui pour les strategies d'adaptation locales | IDRC ...

International Development Research Centre (IDRC) Digital Library (Canada)

Journal supplement features 10 years of West African health systems research. In the wake of the devastating Ebola virus outbreak in 2014, increased attention has been paid to West Africa's poorly functioning health systems. View moreJournal supplement features 10 years of West African health systems research ...

Assessment of the potential for international dissemination of Ebola virus via commercial air travel during the 2014 west African outbreak.

Science.gov (United States)

Bogoch, Isaac I; Creatore, Maria I; Cetron, Martin S; Brownstein, John S; Pesik, Nicki; Miniota, Jennifer; Tam, Theresa; Hu, Wei; Nicolucci, Adriano; Ahmed, Saad; Yoon, James W; Berry, Isha; Hay, Simon I; Anema, Aranka; Tatem, Andrew J; MacFadden, Derek; German, Matthew; Khan, Kamran

2015-01-03

The WHO declared the 2014 west African Ebola epidemic a public health emergency of international concern in view of its potential for further international spread. Decision makers worldwide are in need of empirical data to inform and implement emergency response measures. Our aim was to assess the potential for Ebola virus to spread across international borders via commercial air travel and assess the relative efficiency of exit versus entry screening of travellers at commercial airports. We analysed International Air Transport Association data for worldwide flight schedules between Sept 1, 2014, and Dec 31, 2014, and historic traveller flight itinerary data from 2013 to describe expected global population movements via commercial air travel out of Guinea, Liberia, and Sierra Leone. Coupled with Ebola virus surveillance data, we modelled the expected number of internationally exported Ebola virus infections, the potential effect of air travel restrictions, and the efficiency of airport-based traveller screening at international ports of entry and exit. We deemed individuals initiating travel from any domestic or international airport within these three countries to have possible exposure to Ebola virus. We deemed all other travellers to have no significant risk of exposure to Ebola virus. Based on epidemic conditions and international flight restrictions to and from Guinea, Liberia, and Sierra Leone as of Sept 1, 2014 (reductions in passenger seats by 51% for Liberia, 66% for Guinea, and 85% for Sierra Leone), our model projects 2.8 travellers infected with Ebola virus departing the above three countries via commercial flights, on average, every month. 91,547 (64%) of all air travellers departing Guinea, Liberia, and Sierra Leone had expected destinations in low-income and lower-middle-income countries. Screening international travellers departing three airports would enable health assessments of all travellers at highest risk of exposure to Ebola virus infection

Avian influenza virus transmission to mammals.

Science.gov (United States)

Herfst, S; Imai, M; Kawaoka, Y; Fouchier, R A M

2014-01-01

Influenza A viruses cause yearly epidemics and occasional pandemics. In addition, zoonotic influenza A viruses sporadically infect humans and may cause severe respiratory disease and fatalities. Fortunately, most of these viruses do not have the ability to be efficiently spread among humans via aerosols or respiratory droplets (airborne transmission) and to subsequently cause a pandemic. However, adaptation of these zoonotic viruses to humans by mutation or reassortment with human influenza A viruses may result in airborne transmissible viruses with pandemic potential. Although our knowledge of factors that affect mammalian adaptation and transmissibility of influenza viruses is still limited, we are beginning to understand some of the biological traits that drive airborne transmission of influenza viruses among mammals. Increased understanding of the determinants and mechanisms of airborne transmission may aid in assessing the risks posed by avian influenza viruses to human health, and preparedness for such risks. This chapter summarizes recent discoveries on the genetic and phenotypic traits required for avian influenza viruses to become airborne transmissible between mammals.

Avian influenza virus

Science.gov (United States)

Avian influenza virus (AIV) is type A influenza that is adapted to avian host species. Although the virus can be isolated from numerous avian species, the natural host reservoir species are dabbling ducks, shorebirds and gulls. Domestic poultry species (poultry being defined as birds that are rais...

Dietary patterns and nutrient intakes of a South African population ...

African Journals Online (AJOL)

Dietary patterns and nutrient intakes of a South African population and asymptomatic people infected with Human Immunodeficiency Virus: The transition health and urbanisation in South Africa (Thusa) study.

African americans are less likely to have clearance of hepatitis C virus infection: the findings from recent U.S. population data.

Science.gov (United States)

Mir, Heshaam M; Stepanova, Maria; Afendy, Mariam; Kugelmas, Marcelo; Younossi, Zobair M

2012-09-01

Hepatitis C virus (HCV) is the most common cause of chronic liver disease in the United States. African Americans are known to have a higher prevalence of HCV and lower response to anti-HCV therapy. The aim of this study is to assess the differences in the prevalence of chronic HCV infection in according to patients' ethnic background. We used the recent National Health and Nutrition Examination Survey with extensive clinical and laboratory data. Active HCV infection was defined as having HCV-positive antibody with detectable HCV RNA by polymerase chain reaction. HCV clearance was defined as HCV-positive antibody with negative HCV RNA. Clinico-demographic data were compared between anti-HCV positive individuals with or without HCV clearance. The stratum-specific χ test for independence was used. Logistic regression was used to identify independent predictors of HCV clearance. P-values ≤0.05 were considered statistically significant. All analyses were run using SAS 9.1 and SUDAAN 10.0. The cohort included 14,750 adults (age 47.6 ± 0.75 y, 64% white, 21% African American, 10% Hispanics, and 63% male). Of these, 1.32 ± 0.11% were anti-HCV positive with 75.94 ± 4.72% having active HCV viremia. The only parameter significantly different between those who did or did not clear HCV was the proportion of African Americans: 8.0 ± 3.7% versus 24.9 ± 5.0%, P=0.0163. Indeed, the rate of HCV clearance was lowest among African Americans (9.3 ± 3.5%) as compared with both whites (27.2 ± 6.5%) and Hispanics 31.2 ± 9.1% (P<0.05). In multivariate analysis, the only independent predictor of active HCV infection was African American race: odds ratio (95% confidence interval)=3.80 (1.31-11.06), P=0.0151. African Americans not only have lower response to anti-HCV therapy but also are less likely to naturally clear HCV, potentially contributing to higher prevalence of HCV.

Henipavirus RNA in African bats.

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Jan Felix Drexler

Full Text Available BACKGROUND: Henipaviruses (Hendra and Nipah virus are highly pathogenic members of the family Paramyxoviridae. Fruit-eating bats of the Pteropus genus have been suggested as their natural reservoir. Human Henipavirus infections have been reported in a region extending from Australia via Malaysia into Bangladesh, compatible with the geographic range of Pteropus. These bats do not occur in continental Africa, but a whole range of other fruit bats is encountered. One of the most abundant is Eidolon helvum, the African Straw-coloured fruit bat. METHODOLOGY/PRINCIPAL FINDINGS: Feces from E. helvum roosting in an urban setting in Kumasi/Ghana were tested for Henipavirus RNA. Sequences of three novel viruses in phylogenetic relationship to known Henipaviruses were detected. Virus RNA concentrations in feces were low. CONCLUSIONS/SIGNIFICANCE: The finding of novel putative Henipaviruses outside Australia and Asia contributes a significant extension of the region of potential endemicity of one of the most pathogenic virus genera known in humans.

[Viruses and civilization].

Science.gov (United States)

Chastel, C

1999-01-01

A few million years ago, when primates moved from the east African forest to the savannah, they were already infected with endogenous viruses and occultly transmitted them to the prime Homo species. However it was much later with the building of the first large cities in Mesopotamia that interhuman viral transmission began in earnest. Spreading was further enhanced with the organization of the Egyptian, Greek, Roman, and Arab empires around the Mediterranean. Discovery of the New World in 1492 led to an unprecedented clash of civilizations and the destruction of pre-Columbian Indian civilizations. It also led to a rapid spread of viruses across the Atlantic Ocean with the emergence of yellow fever and appearance of smallpox and measles throughout the world. However the greatest opportunities for worldwide viral development have been created by our present, modern civilization. This fact is illustrated by epidemic outbreaks of human immunodeficiency virus, Venezuela hemorrhagic fever, Rift valley fever virus, and monkey pox virus. Close analysis underscores the major role of human intervention in producing these events.

Antigenic and genetic characterization of a divergent African virus, Ikoma lyssavirus.

Science.gov (United States)

Horton, Daniel L; Banyard, Ashley C; Marston, Denise A; Wise, Emma; Selden, David; Nunez, Alejandro; Hicks, Daniel; Lembo, Tiziana; Cleaveland, Sarah; Peel, Alison J; Kuzmin, Ivan V; Rupprecht, Charles E; Fooks, Anthony R

2014-05-01

In 2009, a novel lyssavirus (subsequently named Ikoma lyssavirus, IKOV) was detected in the brain of an African civet (Civettictis civetta) with clinical rabies in the Serengeti National Park of Tanzania. The degree of nucleotide divergence between the genome of IKOV and those of other lyssaviruses predicted antigenic distinction from, and lack of protection provided by, available rabies vaccines. In addition, the index case was considered likely to be an incidental spillover event, and therefore the true reservoir of IKOV remained to be identified. The advent of sensitive molecular techniques has led to a rapid increase in the discovery of novel viruses. Detecting viral sequence alone, however, only allows for prediction of phenotypic characteristics and not their measurement. In the present study we describe the in vitro and in vivo characterization of IKOV, demonstrating that it is (1) pathogenic by peripheral inoculation in an animal model, (2) antigenically distinct from current rabies vaccine strains and (3) poorly neutralized by sera from humans and animals immunized against rabies. In a laboratory mouse model, no protection was elicited by a licensed rabies vaccine. We also investigated the role of bats as reservoirs of IKOV. We found no evidence for infection among 483 individuals of at least 13 bat species sampled across sites in the Serengeti and Southern Kenya.

Catalase activity of cassava (Manihot esculenta) plant under African ...

African Journals Online (AJOL)

aghomotsegin

. E-mail: sabastina.amoako@kintampo-hrc.org. Tel: +233543550743. Abbreviations: CBSD, Cassava brown streak disease; ACMV, African cassava mosaic virus; ROS, reactive oxygen species; H2O2, hydrogen peroxide; BSA, bovine serum ...

Adaptive immunity and histopathology in frog virus 3-infected Xenopus

International Nuclear Information System (INIS)

Robert, Jacques; Morales, Heidi; Buck, Wayne; Cohen, Nicholas; Marr, Shauna; Gantress, Jennifer

2005-01-01

Xenopus has been used as an experimental model to evaluate the contribution of adaptive cellular immunity in amphibian host susceptibility to the emerging ranavirus FV3. Conventional histology and immunohistochemistry reveal that FV3 has a strong tropism for the proximal tubular epithelium of the kidney and is rarely disseminated elsewhere in Xenopus hosts unless their immune defenses are impaired or developmentally immature as in larvae. In such cases, virus is found widespread in most tissues. Adults, immunocompromised by depletion of CD8 + T cells or by sub-lethal γ-irradiation, show increased susceptibility to FV3 infection. Larvae and irradiated (but not normal) adults can be cross-infected through water by infected adult conspecifics (irradiated or not). The natural MHC class I deficiency and the absence of effect of anti-CD8 treatment on both larval CD8 + T cells and larval susceptibility to FV3 are consistent with an inefficient CD8 + T cell effector function during this developmental period

Anatomical and nutritional adaptations in African rodents | Perrin ...

African Journals Online (AJOL)

South African Journal of Animal Science. Journal Home · ABOUT · Advanced Search · Current Issue · Archives · Journal Home > Vol 13, No 1 (1983) >. Log in or Register to get access to full text downloads.

Molecular Determinants of Influenza Virus Pathogenesis in Mice

Science.gov (United States)

Katz, Jaqueline M.; York, Ian A.

2015-01-01

Mice are widely used for studying influenza virus pathogenesis and immunology because of their low cost, the wide availability of mouse-specific reagents, and the large number of mouse strains available, including knockout and transgenic strains. However, mice do not fully recapitulate the signs of influenza infection of humans: transmission of influenza between mice is much less efficient than in humans, and influenza viruses often require adaptation before they are able to efficiently replicate in mice. In the process of mouse adaptation, influenza viruses acquire mutations that enhance their ability to attach to mouse cells, replicate within the cells, and suppress immunity, among other functions. Many such mouse-adaptive mutations have been identified, covering all 8 genomic segments of the virus. Identification and analysis of these mutations have provided insight into the molecular determinants of influenza virulence and pathogenesis, not only in mice but also in humans and other species. In particular, several mouse-adaptive mutations of avian influenza viruses have proved to be general mammalian-adaptive changes that are potential markers of pre-pandemic viruses. As well as evaluating influenza pathogenesis, mice have also been used as models for evaluation of novel vaccines and anti-viral therapies. Mice can be a useful animal model for studying influenza biology as long as differences between human and mice infections are taken into account. PMID:25038937

Detection of a pneumonia virus of mice (PVM) in an African hedgehog (Atelerix arbiventris) with suspected wobbly hedgehog syndrome (WHS).

Science.gov (United States)

Madarame, Hiroo; Ogihara, Kikumi; Kimura, Moe; Nagai, Makoto; Omatsu, Tsutomu; Ochiai, Hideharu; Mizutani, Tetsyuya

2014-09-17

A pneumonia virus of mice (PVM) from an African hedgehog (Atelerix arbiventris) with suspected wobbly hedgehog syndrome (WHS) was detected and genetically characterized. The affected hedgehog had a nonsuppurative encephalitis with vacuolization of the white matter, and the brain samples yielded RNA reads highly homogeneous to PVM strain 15 (96.5% of full genomic sequence homology by analysis of next generation sequencing). PVM antigen was also detected in the brain and the lungs immunohistochemically. A PVM was strongly suggested as a causative agent of encephalitis of a hedgehog with suspected WHS. This is a first report of PVM infection in hedgehogs. Copyright © 2014 Elsevier B.V. All rights reserved.

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...... samples collected from buffalo in three different Kenyan ecosystems; Maasai-Mara (MME) (n = 40), Tsavo (TSE) (n = 33), and Meru (ME) (n = 29). Results Antibodies against FMDV non-structural proteins were found in 65 of 102 (64%) sera from buffalo with 44/102 and 53/102 also having neutralising antibodies...... directed against FMDV SAT 1 and SAT 2, respectively. FMDV RNA was detected in 42% of the buffalo probang samples by RT-qPCR (Cycle Threshold (Ct) ≤32). Two buffalo probang samples were positive by VI and were identified as FMDV SAT 1 and SAT 2 by Ag-ELISA, while the latter assay detected serotypes O (1...

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

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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

Health Belief Model Scale for Human Papilloma Virus and its Vaccination: Adaptation and Psychometric Testing.

Science.gov (United States)

Guvenc, Gulten; Seven, Memnun; Akyuz, Aygul

2016-06-01

To adapt and psychometrically test the Health Belief Model Scale for Human Papilloma Virus (HPV) and Its Vaccination (HBMS-HPVV) for use in a Turkish population and to assess the Human Papilloma Virus Knowledge score (HPV-KS) among female college students. Instrument adaptation and psychometric testing study. The sample consisted of 302 nursing students at a nursing school in Turkey between April and May 2013. Questionnaire-based data were collected from the participants. Information regarding HBMS-HPVV and HPV knowledge and descriptive characteristic of participants was collected using translated HBMS-HPVV and HPV-KS. Test-retest reliability was evaluated and Cronbach α was used to assess internal consistency reliability, and exploratory factor analysis was used to assess construct validity of the HBMS-HPVV. The scale consists of 4 subscales that measure 4 constructs of the Health Belief Model covering the perceived susceptibility and severity of HPV and the benefits and barriers. The final 14-item scale had satisfactory validity and internal consistency. Cronbach α values for the 4 subscales ranged from 0.71 to 0.78. Total HPV-KS ranged from 0 to 8 (scale range, 0-10; 3.80 ± 2.12). The HBMS-HPVV is a valid and reliable instrument for measuring young Turkish women's beliefs and attitudes about HPV and its vaccination. Copyright © 2015 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

Influenza A viruses of avian origin circulating in pigs and other mammals.

Science.gov (United States)

Urbaniak, Kinga; Kowalczyk, Andrzej; Markowska-Daniel, Iwona

2014-01-01

Influenza A viruses (IAVs) are zoonotic agents, capable of crossing the species barriers. Nowadays, they still constitute a great challenge worldwide. The natural reservoir of all influenza A viruses are wild aquatic birds, despite the fact they have been isolated from a number of avian and mammalian species, including humans. Even when influenza A viruses are able to get into another than waterfowl population, they are often unable to efficiently adapt and transmit between individuals. Only in rare cases, these viruses are capable of establishing a new lineage. To succeed a complete adaptation and further transmission between species, influenza A virus must overcome a species barrier, including adaptation to the receptors of a new host, which would allow the virus-cell binding, virus replication and, then, animal-to-animal transmission. For many years, pigs were thought to be intermediate host for adaptation of avian influenza viruses to humans, because of their susceptibility to infection with both, avian and human influenza viruses, which supported hypothesis of pigs as a 'mixing vessel'. In this review, the molecular factors necessary for interspecies transmission are described, with special emphasis on adaptation of avian influenza viruses to the pig population. In addition, this review gives the information about swine influenza viruses circulating around the world with special emphasis on Polish strains.

Coevolution mechanisms that adapt viruses to genetic code ...

Indian Academy of Sciences (India)

Recent work on virus × host inter- ... of long-term interdependent symbiotic relationship between them. ... Evolution in species of living organisms occurs based on the .... their parents (Francino and Ochman 1999; Lynn et al. 2002; ... dently some dozens of times. ... in the families of certain viruses, bacteria, fungi and inverte-.

The "invisible caregiver": multicaregiving among diabetic African-American grandmothers.

Science.gov (United States)

Carthron, Dana L; Bailey, Donald E; Anderson, Ruth A

2014-01-01

To explore the multicaregiving roles African-American grandmothers assume while self-managing their diabetes. This longitudinal, qualitative pilot study explored the challenges of self-managing diabetes among six African-American caregiving grandmothers. Data were collected at 5 times points across 18 months. Content analysis, guided by the Adaptive Leadership framework, was conducted using data matrices to facilitate within-case and cross-case analyses. Although participants initially stated they cared only for grandchildren, all had additional caregiving responsibilities. Four themes emerged which illustrated how African-American caregiving grandmothers put the care of dependent children, extended family and community before themselves. Using the Adaptive Leadership framework, technical and adaptive challenges arising from multicaregiving were described as barriers to diabetes self-management. When assisting these women to self-manage their diabetes, clinicians must assess challenges arising from multicaregiving. This might require developing collaborative work relationships with the client to develop meaningful and attainable goals. Copyright © 2014 Mosby, Inc. All rights reserved.

Immunogenicity in African Green Monkeys of M Protein Mutant Vesicular Stomatitis Virus Vectors and Contribution of Vector-Encoded Flagellin

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Marlena M. Westcott

2018-03-01

Full Text Available Recombinant vesicular stomatitis virus (VSV is a promising platform for vaccine development. M51R VSV, an attenuated, M protein mutant strain, is an effective inducer of Type I interferon and dendritic cell (DC maturation, which are desirable properties to exploit for vaccine design. We have previously evaluated M51R VSV (M51R and M51R VSV that produces flagellin (M51R-F as vaccine vectors using murine models, and found that flagellin enhanced DC activation and VSV-specific antibody production after low-dose vaccination. In this report, the immunogenicity of M51R vectors and the adjuvant effect of virus-produced flagellin were evaluated in nonhuman primates following high-dose (108 pfu and low-dose (105 pfu vaccination. A single intramuscular vaccination of African green monkeys with M51R or M51R-F induced VSV-specific, dose-dependent humoral immune responses. Flagellin induced a significant increase in antibody production (IgM, IgG and neutralizing antibody at the low vaccination dose. A VSV-specific cellular response was detected at 6 weeks post-vaccination, but was neither dose-dependent nor enhanced by flagellin; similar numbers of VSV-specific, IFNγ-producing cells were detected in lymph node and spleen of all animals. These results indicate that virus-directed, intracellular flagellin production may improve VSV-based vaccines encoding heterologous antigens by lowering the dose required to achieve humoral immunity.

Neutralizing antibodies against flaviviruses, Babanki virus, and Rift Valley fever virus in Ugandan bats.

Science.gov (United States)

Kading, Rebekah C; Kityo, Robert M; Mossel, Eric C; Borland, Erin M; Nakayiki, Teddie; Nalikka, Betty; Nyakarahuka, Luke; Ledermann, Jeremy P; Panella, Nicholas A; Gilbert, Amy T; Crabtree, Mary B; Peterhans, Julian Kerbis; Towner, Jonathan S; Amman, Brian R; Sealy, Tara K; Nichol, Stuart T; Powers, Ann M; Lutwama, Julius J; Miller, Barry R

2018-01-01

Introduction: A number of arboviruses have previously been isolated from naturally-infected East African bats, however the role of bats in arbovirus maintenance is poorly understood. The aim of this study was to investigate the exposure history of Ugandan bats to a panel of arboviruses. Materials and methods: Insectivorous and fruit bats were captured from multiple locations throughout Uganda during 2009 and 2011-2013. All serum samples were tested for neutralizing antibodies against West Nile virus (WNV), yellow fever virus (YFV), dengue 2 virus (DENV-2), Zika virus (ZIKV), Babanki virus (BBKV), and Rift Valley fever virus (RVFV) by plaque reduction neutralization test (PRNT). Sera from up to 626 bats were screened for antibodies against each virus. Results and Discussion:  Key findings include the presence of neutralizing antibodies against RVFV in 5/52 (9.6%) of little epauletted fruit bats ( Epomophorus labiatus ) captured from Kawuku and 3/54 (5.6%) Egyptian rousette bats from Kasokero cave. Antibodies reactive to flaviviruses were widespread across bat taxa and sampling locations. Conclusion: The data presented demonstrate the widespread exposure of bats in Uganda to arboviruses, and highlight particular virus-bat associations that warrant further investigation.

The Ebola contagion and forecasting virus: evidence from four African countries.

Science.gov (United States)

Nadhem, Selmi; Nejib, Hachicha D

2015-12-01

This paper is focused on examining the number of deaths' increases participation in the propagating the Ebola virus during the period ranging from March to October 2014. An application of the MGARCH-DCC model regressions on four countries has led to discover that the finding that human contact play a significant role in transmitting the Ebola virus. Our findings also reveal that Guinea has already suffered from a spread-like virus originating from Sierra Lione and Liberia. Noteworthy also, other countries are now liable to such a risk; for instance, Nigeria is a country vulnerable to the propagation of this virus. Consequently, we undertake to conduct our forecasts for EGARCH model estimates implements; which has estimated a decrease in the Ebola virus incurred number of deadly Ebola virus over the two months following the November and December.

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

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......-titer production of diverse HCV strains would be advantageous. Our study offers important functional data on how cell culture-adaptive mutations identified in genotype 5a JFH1-based HCVcc permit high-titer culture by affecting HCV genesis through increasing virus assembly and HCV fitness by enhancing the virus...... specific infectivity and cell-to-cell transmission ability, without influencing the biophysical particle properties. High-titer HCVcc like the one described in this study may be pivotal in future vaccine-related studies where large quantities of infectious HCV particles are necessary....

Epstein-Barr Virus Infektionen. Neue Aspekte zur Pathogenese und Klinik ( = Epstein-Barr virus infections. New pathogenic and clinical aspects)

OpenAIRE

Wilmes, E.; Wolf, Hans J.

1989-01-01

The Epstein-Barr virus (EBV) is among the most widespread of human viruses. It causes several different diseases, such as acute infectious mononucleosis (IM), chronic active EBV-infection (cEBV), the x-linked lymphoproliferative syndrome (XLP), polyclonal and oligoclonal lymphomae in connection with immunologic disorders, as well as African Burkitt's lymphoma and nasopharyngeal carcinoma. Pathogenesis, clinical features and diagnosis are discussed. In this connection, special tests on the lat...

Ethnopharmacology of human immunodeficiency virus in South ...

African Journals Online (AJOL)

Administrator

2006-10-02

Oct 2, 2006 ... This mini-review takes a look at the evaluations of South African medicinal plants to determine ... Key words: Human immunodeficiency virus, Medicinal plants, South Africa. ... The greatest degree of antiviral activity against.

A non mouse-adapted dengue virus strain as a new model of severe dengue infection in AG129 mice.

Directory of Open Access Journals (Sweden)

Grace K Tan

Full Text Available The spread of dengue (DEN worldwide combined with an increased severity of the DEN-associated clinical outcomes have made this mosquito-borne virus of great global public health importance. Progress in understanding DEN pathogenesis and in developing effective treatments has been hampered by the lack of a suitable small animal model. Most of the DEN clinical isolates and cell culture-passaged DEN virus strains reported so far require either host adaptation, inoculation with a high dose and/or intravenous administration to elicit a virulent phenotype in mice which results, at best, in a productive infection with no, few, or irrelevant disease manifestations, and with mice dying within few days at the peak of viremia. Here we describe a non-mouse-adapted DEN2 virus strain (D2Y98P that is highly infectious in AG129 mice (lacking interferon-alpha/beta and -gamma receptors upon intraperitoneal administration. Infection with a high dose of D2Y98P induced cytokine storm, massive organ damage, and severe vascular leakage, leading to haemorrhage and rapid death of the animals at the peak of viremia. In contrast, very interestingly and uniquely, infection with a low dose of D2Y98P led to asymptomatic viral dissemination and replication in relevant organs, followed by non-paralytic death of the animals few days after virus clearance, similar to the disease kinetic in humans. Spleen damage, liver dysfunction and increased vascular permeability, but no haemorrhage, were observed in moribund animals, suggesting intact vascular integrity, a cardinal feature in DEN shock syndrome. Infection with D2Y98P thus offers the opportunity to further decipher some of the aspects of dengue pathogenesis and provides a new platform for drug and vaccine testing.

Different cranial ontogeny in Europeans and Southern Africans.

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Marina L Sardi

Full Text Available Modern human populations differ in developmental processes and in several phenotypic traits. However, the link between ontogenetic variation and human diversification has not been frequently addressed. Here, we analysed craniofacial ontogenies by means of geometric-morphometrics of Europeans and Southern Africans, according to dental and chronological ages. Results suggest that different adult cranial morphologies between Southern Africans and Europeans arise by a combination of processes that involve traits modified during the prenatal life and others that diverge during early postnatal ontogeny. Main craniofacial changes indicate that Europeans differ from Southern Africans by increasing facial developmental rates and extending the attainment of adult size and shape. Since other studies have suggested that native subsaharan populations attain adulthood earlier than Europeans, it is probable that facial ontogeny is linked with other developmental mechanisms that control the timing of maturation in other variables. Southern Africans appear as retaining young features in adulthood. Facial ontogeny in Europeans produces taller and narrower noses, which seems as an adaptation to colder environments. The lack of these morphological traits in Neanderthals, who lived in cold environments, seems a paradox, but it is probably the consequence of a warm-adapted faces together with precocious maturation. When modern Homo sapiens migrated into Asia and Europe, colder environments might establish pressures that constrained facial growth and development in order to depart from the warm-adapted morphology. Our results provide some answers about how cranial growth and development occur in two human populations and when developmental shifts take place providing a better adaptation to environmental constraints.

Dengue virus genomic variation associated with mosquito adaptation defines the pattern of viral non-coding RNAs and fitness in human cells.

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Claudia V Filomatori

2017-03-01

Full Text Available 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

Genetic adaptation of giant lobelias (Lobelia aberdarica and Lobelia telekii to different altitudes in East African mountains

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Shu-Ying eZhao

2016-04-01

Full Text Available The giant lobelias in East African mountains are good models for studying molecular mechanisms of adaptation to different altitudes. In this study, we generated RNA-seq data of a middle-altitude species Lobelia aberdarica and a high-altitude species L. telekii, followed by selective pressure estimation of their orthologous genes. Our aim was to explore the important genes potentially involved in adaptation to different altitudes. About 9.3 Gb of clean nucleotides, 167,929 – 170,534 unigenes with total lengths of 159,762,099 – 171,138,936 bp for each of the two species were generated. OrthoMCL method identified 3,049 1:1 orthologous genes (each species was represented by one ortholog. Estimations of non-synonymous to synonymous rate were performed using an approximate method and a maximum likelihood method in PAML. 85 orthologous genes were under positive selection. At least 8 of these genes are possibly involved in DNA repair, response to DNA damage and temperature stimulus, and regulation of gene expression, which hints on how giant lobelias adapt to high altitudinal environment that characterised by cold, low oxygen and strong ultraviolet radiation. The negatively selected genes are over-represented in Gene ontology terms of hydrolase, macromolecular complex assembly among others. This study sheds light on understanding the molecular mechanism of adaptation to different altitudes, and provides genomic resources for further studies of giant lobelias.

Accelerating vaccine development for African swine fever virus ...

International Development Research Centre (IDRC) Digital Library (Canada)

Photo: IDRC / Bartay The challenge African swine fever (ASF) is a highly infectious hemorrhagic viral disease that wipes out entire herds of infected pigs. ASF is widespread in at least half of sub-Saharan Africa, and threatens food security due to devastating economic losses.

Virus-host interaction in feline immunodeficiency virus (FIV) infection.

Science.gov (United States)

Taniwaki, Sueli Akemi; Figueiredo, Andreza Soriano; Araujo, João Pessoa

2013-12-01

Feline immunodeficiency virus (FIV) infection has been the focus of several studies because this virus exhibits genetic and pathogenic characteristics that are similar to those of the human immunodeficiency virus (HIV). FIV causes acquired immunodeficiency syndrome (AIDS) in cats, nevertheless, a large fraction of infected cats remain asymptomatic throughout life despite of persistent chronic infection. This slow disease progression may be due to the presence of factors that are involved in the natural resistance to infection and the immune response that is mounted by the animals, as well as due to the adaptation of the virus to the host. Therefore, the study of virus-host interaction is essential to the understanding of the different patterns of disease course and the virus persistence in the host, and to help with the development of effective vaccines and perhaps the cure of FIV and HIV infections. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

Science.gov (United States)

de Fouchier, Capucine; Blanchet, Alain; Hopkins, William; Bui, Eric; Ait-Aoudia, Malik; Jehel, Louis

2012-01-01

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. PMID:23233870

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

Directory of Open Access Journals (Sweden)

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.

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

2013-08-01

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.

Feline panleukopaenia virus in captive non-domestic felids in South Africa

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Emily P. Lane

2016-06-01

Full Text Available An outbreak of feline panleukopaenia virus (FPLV infection was diagnosed by pathology, electron microscopy and polymerase chain reaction (PCR in vaccinated captive-bred subadult cheetahs in South Africa. Subsequent to this disease outbreak, 12 cases of FPLV diagnosed on histology were confirmed by PCR in captive African black-footed cat, caracal, cheetah, lion, ocelot and serval. Phylogenetic analyses of the viral capsid protein gene on PCR-positive samples, vaccine and National Center for Biotechnology Information (NCBI reference strains identified a previously unknown strain of FPLV, present since at least 2006, that differs from both the inactivated and the modified live vaccine strains. A previously described South African strain from domestic cats and cheetahs was identified in a serval. Surveys of FPLV strains in South African felids are needed to determine the geographical and host species distribution of this virus. Since non-domestic species may be reservoirs of parvoviruses, and since these viruses readily change host specificity, the risks of FPLV transmission between captive-bred and free-ranging carnivores and domestic cats and dogs warrant further research. Keywords: feline panleukopaenia; parvovirus; felid; cheetah; vaccination

Hepatitis C virus infection: review | Botha | South African ...

African Journals Online (AJOL)

South African Gastroenterology Review. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 1, No 2 (2003) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. DOWNLOAD FULL TEXT Open Access ...

Introduction of East African cassava mosaic Zanzibar virus to Oman harks back to "Zanzibar, the capital of Oman".

Science.gov (United States)

Khan, Akhtar J; Akhtar, Sohail; Al-Matrushi, Abdulrahman M; Fauquet, Claude M; Briddon, Rob W

2013-02-01

Cassava mosaic disease (CMD) is the most devastating disease of the subsistence crop cassava (Manihot esculenta) across Africa and the Indian subcontinent. The disease is caused by viruses of the genus Begomovirus (family Geminiviridae)-seven species have been identified so far. The Sultanate of Oman is unusual among countries in Arabia in growing cassava on a small scale for local consumption. During a recent survey in A'Seeb wilayat of Muscat governorate, Oman, cassava plants were identified with symptoms typical of CMD. A begomovirus, East African cassava mosaic Zanzibar virus (EACMZV), was isolated from symptomatic plants. This virus was previously only known to occur in Zanzibar and Kenya. During the 19th Century, Zanzibar was governed by Oman and was so important that the Sultan of Oman moved his capital there from Muscat. After a period of colonial rule, the governing Arab elite was overthrown, following independence in the 1960s, and many expatriate Omanis returned to their homeland. Having gained a liking for the local Zanzibar cuisine, it appears that returning Omanis did not wish to do without dishes made from one particular favorite, cassava. Consequently, they carried planting material back to Oman for cultivation in their kitchen gardens. The evidence suggests that this material harbored EACMZV. Recently, Oman has been shown to be a nexus for geminiviruses and their associated satellites from diverse geographic origins. With their propensity to recombine, a major mechanism for evolution of geminiviruses, and the fact that Oman (and several other Arabian countries) is a major hub for trade and travel by air and sea, the possibility of onward spread is worrying.

Herpesvirus-like respiratory infection in African penguins Spheniscus demersus admitted to a rehabilitation centre.

Science.gov (United States)

Parsons, Nola J; Gous, Tertius A; van Wilpe, Erna; Strauss, Venessa; Vanstreels, Ralph Eric

2015-10-16

Rehabilitation is an important strategy for the conservation of the Endangered African penguin Spheniscus demersus, and disease has been raised as a concern in the management of the species, both in the wild and in rehabilitation centres. We report 8 cases of herpesvirus-like respiratory infection in African penguin chicks undergoing rehabilitation between 2010 and 2013 at a facility in Cape Town, South Africa. Infection was confirmed through the identification of viral inclusions in the tracheal epithelium and demonstration of particles consistent with herpesvirus by electron microscopy, whereas virus isolation in eggs, serology and PCR testing failed to detect the virus. Only penguin chicks were affected; they were in poor body condition, and in 2 cases infection occurred prior to admission to the rehabilitation centre. The role played by the herpesvirus-like infection in the overall respiratory disease syndrome is uncertain, due to identification of lesions in only a small proportion of the chicks as well as to the occurrence of other concurrent pathological processes. Further studies are advised to characterise the specific virus involved through the development of sensitive diagnostic methods and to clarify the epidemiology and significance of these infections in wild African penguins.

The diagnosis and prevalence of persistent infection with bovine viral diarrhoea virus in South African feedlot cattle

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Thelma Meiring

2011-08-01

Full Text Available Bovine viral diarrhoea virus (BVDV infection is an important viral infection affecting the cattle industry today. The prevalence of this infection in South African feedlots is unknown. Ear notch biopsies were collected from chronic poor doers and animals that appeared unthrifty upon entering feedlots, as well as animals entering the hospital pen with respiratory disease for the first time. A total of 1690 samples were collected: 1074 from the former category and 616 from the latter. A routine immunohistochemistry staining protocol showed that 49 animals tested positive, of which 43 (4% came from the feedlot entry group and six (1% from the hospitalised group. The prevalence of persistently infected cattle from this selected, nonrandom sample entering six large South African feedlots was found to be 2.9%, which is higher than the international rule of thumb that 0.5% of all cattle entering feedlots are persistently infected. There was no clear correlation between persistent infection and respiratory disease. Serum samples were also collected when possible and 10 positive cases were found. Results from enzyme-linked immunosorbent assays for antigen and antibody performed on these sera correlated well with those from the immunohistochemistry staining method in six cases, but in four cases the animals tested falsely positive owing to nonspecific staining. Immunohistochemistry staining on ear notch biopsies is thus a reliable diagnostic method to identify persistently infected animals with BVDV, but the pathologist should be aware of nonspecific positive staining.

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

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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.

Single virus genomics: a new tool for virus discovery.

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Lisa Zeigler Allen

Full Text Available Whole genome amplification and sequencing of single microbial cells has significantly influenced genomics and microbial ecology by facilitating direct recovery of reference genome data. However, viral genomics continues to suffer due to difficulties related to the isolation and characterization of uncultivated viruses. We report here on a new approach called 'Single Virus Genomics', which enabled the isolation and complete genome sequencing of the first single virus particle. A mixed assemblage comprised of two known viruses; E. coli bacteriophages lambda and T4, were sorted using flow cytometric methods and subsequently immobilized in an agarose matrix. Genome amplification was then achieved in situ via multiple displacement amplification (MDA. The complete lambda phage genome was recovered with an average depth of coverage of approximately 437X. The isolation and genome sequencing of uncultivated viruses using Single Virus Genomics approaches will enable researchers to address questions about viral diversity, evolution, adaptation and ecology that were previously unattainable.

Type I Interferon Reaction to Viral Infection in Interferon-Competent, Immortalized Cell Lines from the African Fruit Bat Eidolon helvum

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Biesold, Susanne E.; Ritz, Daniel; Gloza-Rausch, Florian; Wollny, Robert; Drexler, Jan Felix; Corman, Victor M.; Kalko, Elisabeth K. V.; Oppong, Samuel; Drosten, Christian; Müller, Marcel A.

2011-01-01

Bats harbor several highly pathogenic zoonotic viruses including Rabies, Marburg, and henipaviruses, without overt clinical symptoms in the animals. It has been suspected that bats might have evolved particularly effective mechanisms to suppress viral replication. Here, we investigated interferon (IFN) response, -induction, -secretion and -signaling in epithelial-like cells of the relevant and abundant African fruit bat species, Eidolon helvum (E. helvum). Immortalized cell lines were generated; their potential to induce and react on IFN was confirmed, and biological assays were adapted to application in bat cell cultures, enabling comparison of landmark IFN properties with that of common mammalian cell lines. E. helvum cells were fully capable of reacting to viral and artificial IFN stimuli. E. helvum cells showed highest IFN mRNA induction, highly productive IFN protein secretion, and evidence of efficient IFN stimulated gene induction. In an Alphavirus infection model, O'nyong-nyong virus exhibited strong IFN induction but evaded the IFN response by translational rather than transcriptional shutoff, similar to other Alphavirus infections. These novel IFN-competent cell lines will allow comparative research on zoonotic, bat-borne viruses in order to model mechanisms of viral maintenance and emergence in bat reservoirs. PMID:22140523

Full Genome Sequencing Reveals New Southern African Territories Genotypes Bringing Us Closer to Understanding True Variability of Foot-and-Mouth Disease Virus in Africa

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Lasecka-Dykes, Lidia; Wright, Caroline F.; Di Nardo, Antonello; Logan, Grace; Mioulet, Valerie; Jackson, Terry; Tuthill, Tobias J.; Knowles, Nick J.; King, Donald P.

2018-01-01

Foot-and-mouth disease virus (FMDV) causes a highly contagious disease of cloven-hooved animals that poses a constant burden on farmers in endemic regions and threatens the livestock industries in disease-free countries. Despite the increased number of publicly available whole genome sequences, FMDV data are biased by the opportunistic nature of sampling. Since whole genomic sequences of Southern African Territories (SAT) are particularly underrepresented, this study sequenced 34 isolates from eastern and southern Africa. Phylogenetic analyses revealed two novel genotypes (that comprised 8/34 of these SAT isolates) which contained unusual 5′ untranslated and non-structural encoding regions. While recombination has occurred between these sequences, phylogeny violation analyses indicated that the high degree of sequence diversity for the novel SAT genotypes has not solely arisen from recombination events. Based on estimates of the timing of ancestral divergence, these data are interpreted as being representative of un-sampled FMDV isolates that have been subjected to geographical isolation within Africa by the effects of the Great African Rinderpest Pandemic (1887–1897), which caused a mass die-out of FMDV-susceptible hosts. These findings demonstrate that further sequencing of African FMDV isolates is likely to reveal more unusual genotypes and will allow for better understanding of natural variability and evolution of FMDV. PMID:29652800

Culicoides (Diptera: Ceratopogonidae) midges, the vectors of African horse sickness virus--a host/vector contact study in the Niayes area of Senegal.

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Fall, Moussa; Diarra, Maryam; Fall, Assane G; Balenghien, Thomas; Seck, Momar T; Bouyer, Jérémy; Garros, Claire; Gimonneau, Geoffrey; Allène, Xavier; Mall, Iba; Delécolle, Jean-Claude; Rakotoarivony, Ignace; Bakhoum, Mame T; Dusom, Ange M; Ndao, Massouka; Konaté, Lassana; Faye, Ousmane; Baldet, Thierry

2015-01-21

African horse sickness (AHS) is an equine disease endemic to Senegal. The African horse sickness virus (AHSV) is transmitted to the mammalian hosts by midges of the Culicoides Latreille genus. During the last epizootic outbreak of AHS in Senegal in 2007, 1,169 horses died from this disease entailing an estimated cost of 1.4 million euros. In spite of the serious animal health and economic implications of AHS, very little is known about determinants involved in transmission such as contact between horses and the Culicoides species suspected of being its vectors. The monthly variation in host/vector contact was determined in the Niayes area, Senegal, an area which was severely affected by the 2007 outbreak of AHS. A horse-baited trap and two suction light traps (OVI type) were set up at each of five sites for three consecutive nights every month for one year. Of 254,338 Culicoides midges collected 209,543 (82.4%) were female and 44,795 (17.6%) male. Nineteen of the 41 species collected were new distribution records for Senegal. This increased the number of described Culicoides species found in Senegal to 53. Only 19 species, of the 41 species found in light trap, were collected in the horse-baited trap (23,669 specimens) largely dominated by Culicoides oxystoma (22,300 specimens, i.e. 94.2%) followed by Culicoides imicola (482 specimens, i.e. 2.0%) and Culicoides kingi (446 specimens, i.e. 1.9%). Culicoides oxystoma should be considered as a potential vector of AHSV in the Niayes area of Senegal due to its abundance on horses and its role in the transmission of other Culicoides-borne viruses.

Immunopathology of highly virulent pathogens: insights from Ebola virus.

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Zampieri, Carisa A; Sullivan, Nancy J; Nabel, Gary J

2007-11-01

Ebola virus is a highly virulent pathogen capable of inducing a frequently lethal hemorrhagic fever syndrome. Accumulating evidence indicates that the virus actively subverts both innate and adaptive immune responses and triggers harmful inflammatory responses as it inflicts direct tissue damage. The host immune system is ultimately overwhelmed by a combination of inflammatory factors and virus-induced cell damage, particularly in the liver and vasculature, often leading to death from septic shock. We summarize the mechanisms of immune dysregulation and virus-mediated cell damage in Ebola virus-infected patients. Future approaches to prevention and treatment of infection will be guided by answers to unresolved questions about interspecies transmission, molecular mechanisms of pathogenesis, and protective adaptive and innate immune responses to Ebola virus.

Rapid Identification of Dengue Virus Serotypes Using Monoclonal Antibodies in an Indirect Immunofluorescence Test.

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1982-06-18

encephalitis(TBH-28), West Nile(E-101), Yellow fever(French neurotropic and 17D strains), and Zika . Two Sandfly Fever viruses (213452 and Candiru) were...were provided as first passage isolates ( Aedes pseudoscutellaris cells, AP-61) or human serum from recent dengue virus patients. African isolates... viruses of the Phlebovirus genus (Table 1). Several monoclonal antibody preparations reacted solely with dengue virus serotypes. Two preparations (13E7 and

Faith-Based Mental Health Interventions with African Americans: A Review

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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,…

Malignant lymphoma in african lions (panthera leo).

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Harrison, T M; McKnight, C A; Sikarskie, J G; Kitchell, B E; Garner, M M; Raymond, J T; Fitzgerald, S D; Valli, V E; Agnew, D; Kiupel, M

2010-09-01

Malignant lymphoma has become an increasingly recognized problem in African lions (Panthera leo). Eleven African lions (9 male and 2 female) with clinical signs and gross and microscopic lesions of malignant lymphoma were evaluated in this study. All animals were older adults, ranging in age from 14 to 19 years. Immunohistochemically, 10 of the 11 lions had T-cell lymphomas (CD3(+), CD79a(-)), and 1 lion was diagnosed with a B-cell lymphoma (CD3(-), CD79a(+)). The spleen appeared to be the primary site of neoplastic growth in all T-cell lymphomas, with involvement of the liver (6/11) and regional lymph nodes (5/11) also commonly observed. The B-cell lymphoma affected the peripheral lymph nodes, liver, and spleen. According to the current veterinary and human World Health Organization classification of hematopoietic neoplasms, T-cell lymphoma subtypes included peripheral T-cell lymphoma (4/11), precursor (acute) T-cell lymphoblastic lymphoma/leukemia (2/11), chronic T-cell lymphocytic lymphoma/leukemia (3/11), and T-zone lymphoma (1/11). The single B-cell lymphoma subtype was consistent with diffuse large B-cell lymphoma. Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) testing by immunohistochemistry on sections of malignant lymphoma was negative for all 11 lions. One lion was seropositive for FeLV. In contrast to domestic and exotic cats, in which B-cell lymphomas are more common than T-cell lymphomas, African lions in this study had malignant lymphomas that were primarily of T-cell origin. Neither FeLV nor FIV, important causes of malignant lymphoma in domestic cats, seems to be significant in the pathogenesis of malignant lymphoma in African lions.

Pathogenesis and sexual transmission of Spondweni and Zika viruses.

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Erin M McDonald

2017-10-01

Full Text Available The Spondweni serogroup of viruses (Flaviviridae, Flavivirus is comprised of Spondweni virus (SPONV and Zika virus (ZIKV, which are mosquito-borne viruses capable of eliciting human disease. Numerous cases of ZIKV sexual transmission in humans have been documented following the emergence of the Asian genotype in the Americas. The African ZIKV genotype virus was previously implicated in the first reported case of ZIKV sexual transmission. Reports of SPONV infection in humans have been associated with non-specific febrile illness, but no association with sexual transmission has been reported. In order to assess the relative efficiency of sexual transmission of different ZIKV strains and the potential capacity of SPONV to be sexually transmitted, viral loads in the male reproductive tract and in seminal fluids were assessed in interferon α/β and -γ receptor deficient (AG129 mice. Male mice were inoculated subcutaneously with Asian genotype ZIKV strains PRVABC59 (Puerto Rico, 2015, FSS13025 (Cambodia, 2010, or P6-740 (Malaysia, 1966; African genotype ZIKV strain DakAr41524 (Senegal, 1984; or SPONV strain SAAr94 (South Africa, 1955. Infectious virus was detected in 60-72% of ejaculates collected from AG129 mice inoculated with ZIKV strains. In contrast, only 4% of ejaculates from SPONV-inoculated AG129 males were found to contain infectious virus, despite viral titers in the testes that were comparable to those of ZIKV-inoculated mice. Based on these results, future studies should be undertaken to assess the role of viral genetic determinants and host tropism that dictate the differential sexual transmission potential of ZIKV and SPONV.

Comparison of pathogenic domains of rabies and African rabies-related lyssaviruses and pathogenicity observed in mice

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Joe Kgaladi

2013-03-01

Full Text Available Several lyssavirus species occur in Africa (Rabies virus, Lagos bat virus, Mokola virus, Duvenhage virus, Shimoni bat virus and Ikoma lyssavirus, displaying a high sequence diversity between isolates belonging to the same species. There is limited information about comparative pathogenesis of these African lyssaviruses and this precludes authoritative opinion on the potential public and veterinary health impact. In this study, an analysis of representative African lyssaviruses attempted to correlate viral genomic sequence similarities and differences with the corresponding pathogenic profiles observed in mice. The study demonstrated that the virus isolates evaluated could be lethal to mice when introduced intramuscularly and that different isolates of the same lyssavirus species differ in their virulence. Using real-time polymerase chain reaction (PCR, viral RNA was detected in brain tissue, but no viral RNA was detected in the salivary glands or blood of mice that succumbed to infection. Comparison of known pathogenic domains indicated that pathogenicity is likely to be dependent on multiple domains. Cumulatively, our results re-emphasised the realisation that the pathogenicity of a lyssavirus species cannot be deduced based on studies of only a single isolate of the species or a single pathogenic domain.

How student teachers understand African philosophy

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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.

Sodium phenylbutyrate abrogates African swine fever virus replication by disrupting the virus-induced hypoacetylation status of histone H3K9/K14.

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Frouco, Gonçalo; Freitas, Ferdinando B; Martins, Carlos; Ferreira, Fernando

2017-10-15

African swine fever virus (ASFV) causes a highly lethal disease in swine for which neither a vaccine nor treatment are available. Recently, a new class of drugs that inhibit histone deacetylases enzymes (HDACs) has received an increasing interest as antiviral agents. Considering studies by others showing that valproic acid, an HDAC inhibitor (HDACi), blocks the replication of enveloped viruses and that ASFV regulates the epigenetic status of the host cell by promoting heterochromatinization and recruitment of class I HDACs to viral cytoplasmic factories, the antiviral activity of four HDACi against ASFV was evaluated in this study. Results showed that the sodium phenylbutyrate fully abrogates the ASFV replication, whereas the valproic acid leads to a significant reduction of viral progeny at 48h post-infection (-73.9%, p=0.046), as the two pan-HDAC inhibitors tested (Trichostatin A: -82.2%, p=0.043; Vorinostat: 73.9%, p=0.043). Further evaluation showed that protective effects of NaPB are dose-dependent, interfering with the expression of late viral genes and reversing the ASFV-induced histone H3 lysine 9 and 14 (H3K9K14) hypoacetylation status, compatible to an open chromatin state and possibly enabling the expression of host genes non-beneficial to infection progression. Additionally, a synergic antiviral effect was detected when NaPB is combined with an ASFV-topoisomerase II poison (Enrofloxacin). Altogether, our results strongly suggest that cellular HDACs are involved in the establishment of ASFV infection and emphasize that further in vivo studies are needed to better understand the antiviral activity of HDAC inhibitors. Copyright © 2017 Elsevier B.V. All rights reserved.

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

2010-03-01

Full Text Available 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.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.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 colonize new lakes. Characterizing the changes in cichlid trophic

Distemper Outbreak and Its Effect on African Wild Dog Conservation

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van de Bildt, Marco W.G.; Kuiken, Thijs; Visee, Aart M.; Lema, Sangito; Fitzjohn, Tony R.

2002-01-01

In 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 isolation, reverse transcriptase-polymerase chain reaction analysis, and nucleotide sequencing. This report emphasizes the importance of adequate protection against infectious diseases for the successful outcome of captive breeding programs of endangered species. PMID:11897078

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.

Giving Our Daughters What We Never Received: African American Mothers Discussing Sexual Health with Their Preadolescent Daughters

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Grigsby, Sheila R.

2018-01-01

African American girls experience disparate rates of pregnancy and acquisition of sexually transmitted infections, including human immunodeficiency virus, when compared to their non-Hispanic White counterparts. Among African American girls, current pregnancy rates are equal to the national crisis levels of teen pregnancy reported in 1990. This…

Canine parvovirus type 2 (CPV-2) and Feline panleukopenia virus (FPV) codon bias analysis reveals a progressive adaptation to the new niche after the host jump.

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Franzo, Giovanni; Tucciarone, Claudia Maria; Cecchinato, Mattia; Drigo, Michele

2017-09-01

Based on virus dependence from host cell machinery, their codon usage is expected to show a strong relation with the host one. Even if this association has been stated, especially for bacteria viruses, the linkage is considered to be less consistent for more complex organisms and a codon bias adaptation after host jump has never been proven. Canine parvovirus type 2 (CPV-2) was selected as a model because it represents a well characterized case of host jump, originating from Feline panleukopenia virus (FPV). The current study demonstrates that the adaptation to specific tissue and host codon bias affected CPV-2 evolution. Remarkably, FPV and CPV-2 showed a higher closeness toward the codon bias of the tissues they display the higher tropism for. Moreover, after the host jump, a clear and significant trend was evidenced toward a reduction in the distance between CPV-2 and the dog codon bias over time. This evidence was not confirmed for FPV, suggesting that an equilibrium has been reached during the prolonged virus-host co-evolution. Additionally, the presence of an intermediate pattern displayed by some strains infecting wild species suggests that these could have facilitated the host switch also by acting on codon bias. Copyright © 2017 Elsevier Inc. All rights reserved.

Molecular epidemiology of infectious bursal disease virus in Zambia

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Christopher J. Kasanga

2013-10-01

Full Text Available Nucleotide sequences of the VP2 hypervariable region (VP2-HVR of 10 infectious bursal disease viruses detected in indigenous and exotic chickens in Zambia from 2004 to 2005 were determined. Phylogenetic analysis showed that the viruses diverged into two genotypes and belonged to the African very virulent types (VV1 and VV2. In the phylogenetic tree, strains in one genotype clustered in a distinct group and were closely related to some strains isolated in western Africa (VV1, with nucleotide similarities of 95.7%– 96.5%. Strains in the other genotype were clustered within the eastern African VV type (VV2, with nucleotide similarities of 97.3%– 98.5%. Both genotypes were distributed in the southern parts of Zambia and had a unique conserved amino acid substitution at 300 (E→A in addition to the putative virulence marker at positions 222(A, 242(I, 256(I, 294(I and 299(S. These findings represent the first documentation of the existence of the African VV-IBDV variants in both indigenous and exotic chickens in Zambia.

Avian infectious bronchitis virus in Africa: a review.

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Khataby, Khadija; Fellahi, Siham; Loutfi, Chafiqa; Mustapha, Ennaji Moulay

2016-06-01

Infectious bronchitis virus (IBV) is worldwide in distribution, highly infectious, and extremely difficult to control because it has extensive genetic diversity, a short generation time, and a high mutation rate. IBV is a Gammacoronavirus, single-stranded, and positive-sense RNA virus. Avian infectious bronchitis is well studied in European countries with identification of a large number of IBV variants, whereas in African countries epidemiological and scientific data are poor and not updated. However, previous studies reported that an IBV variant continues to appear regularly in Africa, as currently described in Morocco. No cross-protection between IBV strains was reported, some being unique to a particular country, others having a more general distribution. This review aims to provide a general overview on IB disease distribution in African countries and an update on the available studies of IBV variants in each country.

Human Immunodeficiency Virus (HIV) Seropositivity In African ...

African Journals Online (AJOL)

A seroprevalence study of Human immunodeficiency virus (HIV) infection in new patients attending the eye clinic of LAUTECH Teaching Hospital in Osogbo, Osun State, Nigeria showed that twenty-nine patients 2.7%) were positive to HIV1. No patient was positive to HIV 2. There were 21 males (72.4%) and 8 females ...

African, Amerindian and European hepatitis B virus strains circulate on the Caribbean Island of Martinique.

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Brichler, Ségolène; Lagathu, Gisèle; Chekaraou, Mariama Abdou; Le Gal, Frédéric; Edouard, André; Dény, Paul; Césaire, Raymond; Gordien, Emmanuel

2013-10-01

Ten Hepatitis B virus (HBV) genotypes, as well as numerous subgenotypes, have been described in well-characterized ethnogeographical populations. Martinique has been at a crossroads between Africa, Europe, India and the Americas because of the slave trade (17th-19th centuries), followed by an important immigration of Indian and West African workers. In this work, we aimed to study the molecular epidemiology of HBV infection in Martinique according to this unique settlement pattern. To that end, blood samples from 86 consecutive HBV-infected patients from the main hospitals of the island, were retrospectively analysed. Direct sequencing of the pre-S1 or pre-C-C region or complete genome sequencing, followed by phylogenetic analyses were performed. HBV genotypes were: HBV/A1 (68.6 %), HBV/A2 (10.5 %), HBV/D, mainly HBV/D3 and HBV/D4 (8.1 %), HBV/F (3.5 %), and also HBV/E (2.3 %), two strains isolated from two West-African patients. Moreover, 74 % of the HBeAg-negative strains harboured classical pre-C-C mutations, and most HBV/A1 strains also containing specific mutations. Finally, various patterns of deletion mutants in pre-S and pre-C-C regions were found. In conclusion, our findings point to historical and migration-related issues in HBV-genotype distribution suggesting that HBV/A1, but not HBV/E, was imported from Africa during the slave trade, and further supporting the hypothesis that HBV/E has emerged recently in West Africa (<150 years). Potential origins of 'European' HBV/A2 and HBV/D3, 'Amerindian' HBV/F, and HBV/D4 strains are also discussed. Such HBV genetic diversity, beyond its epidemiological interest, may have a clinical impact on the natural history of HBV infection in Martinique.

The Chlorella variabilis NC64A Genome Reveals Adaptation to Photosymbiosis, Coevolution with Viruses, and Cryptic Sex

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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.

Energy-conserving mechanisms as adaptation to undernutrition and water deprivation in the African Zebu

International Nuclear Information System (INIS)

Finch, V.A.; King, J.M.

1982-01-01

In a study designed to simulate pastoral cattle management practices on marginal and rangelands in Kenya, the physiological adaptations for energy conservation were investigated in African Zebu cattle during a period of undernutrition and water deprivation. In experimental design, the food available to cattle was restricted to 50% of maintenance, watering reduced to every 2 d and distances walked increased from 8 to 16 km/d. Restricting food for nearly 3 months resulted in a 13-14% weight loss in cattle. A 2-day watering regime did not decrease food intake. Cattle that walked the longer distances lost slightly more weight but not significantly more. There was a significant overall reduction in water requirements. Slowing water turnover is seen as adaptive in a water-limited environment. The water turnover rate was determined using the tritiated water dilution technique. Higher solar intensities increased water turnover somewhat, as did extending walking distances. The resting metabolic rate of cattle on restricted food and water was reduced to 30% below that of well-fed and daily watered cattle. This reduction in metabolic requirements would result in conserving energy in dry seasons. Cattle became more thermolabile when offered smaller quantities of food. A heat debt was incurred at night and sweating rates were regulated at low levels during the day, resulting in heat storage. It is suggested that this is a mechanism by which energy is conserved through increasing thermogenesis to maintain body temperature within the normal range

Glycosylation of Hemagglutinin and Neuraminidase of Influenza A Virus as Signature for Ecological Spillover and Adaptation among Influenza Reservoirs

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Paul Kim

2018-04-01

Full Text Available Glycosylation of the hemagglutinin (HA and neuraminidase (NA of the influenza provides crucial means for immune evasion and viral fitness in a host population. However, the time-dependent dynamics of each glycosylation sites have not been addressed. We monitored the potential N-linked glycosylation (NLG sites of over 10,000 HA and NA of H1N1 subtype isolated from human, avian, and swine species over the past century. The results show a shift in glycosylation sites as a hallmark of 1918 and 2009 pandemics, and also for the 1976 “abortive pandemic”. Co-segregation of particular glycosylation sites was identified as a characteristic of zoonotic transmission from animal reservoirs, and interestingly, of “reverse zoonosis” of human viruses into swine populations as well. After the 2009 pandemic, recent isolates accrued glycosylation at canonical sites in HA, reflecting gradual seasonal adaptation, and a novel glycosylation in NA as an independent signature for adaptation among humans. Structural predictions indicated a remarkably pleiotropic influence of glycans on multiple HA epitopes for immune evasion, without sacrificing the receptor binding of HA or the activity of NA. The results provided the rationale for establishing the ecological niche of influenza viruses among the reservoir and could be implemented for influenza surveillance and improving pandemic preparedness.

Glycosylation of Hemagglutinin and Neuraminidase of Influenza A Virus as Signature for Ecological Spillover and Adaptation among Influenza Reservoirs

Science.gov (United States)

Kim, Paul; Jang, Yo Han; Kwon, Soon Bin; Lee, Chung Min; Han, Gyoonhee; Seong, Baik Lin

2018-01-01

Glycosylation of the hemagglutinin (HA) and neuraminidase (NA) of the influenza provides crucial means for immune evasion and viral fitness in a host population. However, the time-dependent dynamics of each glycosylation sites have not been addressed. We monitored the potential N-linked glycosylation (NLG) sites of over 10,000 HA and NA of H1N1 subtype isolated from human, avian, and swine species over the past century. The results show a shift in glycosylation sites as a hallmark of 1918 and 2009 pandemics, and also for the 1976 “abortive pandemic”. Co-segregation of particular glycosylation sites was identified as a characteristic of zoonotic transmission from animal reservoirs, and interestingly, of “reverse zoonosis” of human viruses into swine populations as well. After the 2009 pandemic, recent isolates accrued glycosylation at canonical sites in HA, reflecting gradual seasonal adaptation, and a novel glycosylation in NA as an independent signature for adaptation among humans. Structural predictions indicated a remarkably pleiotropic influence of glycans on multiple HA epitopes for immune evasion, without sacrificing the receptor binding of HA or the activity of NA. The results provided the rationale for establishing the ecological niche of influenza viruses among the reservoir and could be implemented for influenza surveillance and improving pandemic preparedness. PMID:29642453

Spectrum of female commercial sex work in Bangui, Central African ...

African Journals Online (AJOL)

Classification of professional and non-professional female sex workers (FSWs) into different categories, never previously reported in the Central African Republic (CAR), may be useful to assess the dynamics of the human immunodeficiency virus (HIV) epidemic, design operational intervention programmes to combat HIV ...

Pathogenicity Comparison Between the Kikwit and Makona Ebola Virus Variants in Rhesus Macaques.

Science.gov (United States)

Wong, Gary; Qiu, Xiangguo; de La Vega, Marc-Antoine; Fernando, Lisa; Wei, Haiyan; Bello, Alexander; Fausther-Bovendo, Hugues; Audet, Jonathan; Kroeker, Andrea; Kozak, Robert; Tran, Kaylie; He, Shihua; Tierney, Kevin; Soule, Geoff; Moffat, Estella; Günther, Stephan; Gao, George F; Strong, Jim; Embury-Hyatt, Carissa; Kobinger, Gary

2016-10-15

Enhanced virulence and/or transmission of West African Ebola virus (EBOV) variants, which are divergent from their Central African counterparts, are suspected to have contributed to the sizable toll of the recent Ebola virus disease (EVD) outbreak. This study evaluated the pathogenicity and shedding in rhesus macaques infected with 1 of 2 West African isolates (EBOV-C05 or EBOV-C07) or a Central African isolate (EBOV-K). All animals infected with EBOV-C05 or EBOV-C07 died of EVD, whereas 2 of 3 EBOV-K-infected animals died. The viremia level was elevated 10-fold in EBOV-C05-infected animals, compared with EBOV-C07- or EBOV-K-infected animals. More-severe lung pathology was observed in 2 of 6 EBOV-C05/C07-infected macaques. This is the first detailed analysis of the recently circulating EBOV-C05/C07 in direct comparison to EBOV-K with 6 animals per group, and it showed that EBOV-C05 but not EBOV-C07 can replicate at higher levels and cause more tissue damage in some animals. Increased virus shedding from individuals who are especially susceptible to EBOV replication is possibly one of the many challenges facing the community of healthcare and policy-making responders since the beginning of the outbreak. © Crown copyright 2016.

Adaptation to human populations is revealed by within-host polymorphisms in HIV-1 and hepatitis C virus.

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Art F Y Poon

2007-03-01

Full Text Available CD8(+ cytotoxic T-lymphocytes (CTLs perform a critical role in the immune control of viral infections, including those caused by human immunodeficiency virus type 1 (HIV-1 and hepatitis C virus (HCV. As a result, genetic variation at CTL epitopes is strongly influenced by host-specific selection for either escape from the immune response, or reversion due to the replicative costs of escape mutations in the absence of CTL recognition. Under strong CTL-mediated selection, codon positions within epitopes may immediately "toggle" in response to each host, such that genetic variation in the circulating virus population is shaped by rapid adaptation to immune variation in the host population. However, this hypothesis neglects the substantial genetic variation that accumulates in virus populations within hosts. Here, we evaluate this quantity for a large number of HIV-1- (n > or = 3,000 and HCV-infected patients (n > or = 2,600 by screening bulk RT-PCR sequences for sequencing "mixtures" (i.e., ambiguous nucleotides, which act as site-specific markers of genetic variation within each host. We find that nonsynonymous mixtures are abundant and significantly associated with codon positions under host-specific CTL selection, which should deplete within-host variation by driving the fixation of the favored variant. Using a simple model, we demonstrate that this apparently contradictory outcome can be explained by the transmission of unfavorable variants to new hosts before they are removed by selection, which occurs more frequently when selection and transmission occur on similar time scales. Consequently, the circulating virus population is shaped by the transmission rate and the disparity in selection intensities for escape or reversion as much as it is shaped by the immune diversity of the host population, with potentially serious implications for vaccine design.

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

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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.

Ebola Virus Diseases | Elisha | African Journal of Clinical and ...

African Journals Online (AJOL)

African Journal of Clinical and Experimental Microbiology. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 15, No 3 (2014) >. Log in or Register to get access to full text downloads.

Viruses and Cancer | Adegboyega | African Journal of Clinical and ...

African Journals Online (AJOL)

African Journal of Clinical and Experimental Microbiology. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 13, No 1 (2012) >. Log in or Register to get access to full text downloads.

African Crop Science Journal - Vol 2, No 4 (1994)

African Journals Online (AJOL)

Control of the cassava mealybug in Africa: lessons from a biological control ... Analysis and modelling of the temporal spread of African cassava mosaic virus and ... state of knowledge and implications for designing control strategies · EMAIL FREE ... Inventory of cassava plant protection and development projects in Africa ...

African Journal of Biotechnology - Vol 12, No 32 (2013)

African Journals Online (AJOL)

Characterization of Tomato Leaf Curl New Delhi Virus infecting cucurbits: Evidence for sap transmission in a host specific manner · EMAIL FREE FULL TEXT EMAIL FREE ... A critical scientific review on South African governance of genetically modified organisms (GMOs) · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

Obesity, appearance, and psychosocial adaptation in young African American children.

Science.gov (United States)

Young-Hyman, Deborah; Schlundt, David G; Herman-Wenderoth, Leanna; Bozylinski, Khristine

2003-01-01

To evaluate the contributions of weight status, skin tone, peer teasing, and parental appraisals of child's size to self-esteem and psychosocial adjustment in overweight African American children. Overweight to very obese 5- to 10-year-old African American children (N = 117) completed measures of self-esteem, skin tone satisfaction, peer teasing, and body size perception. Caregivers completed the Child Behavior Checklist and rated their child's body size. Overweight was associated with low appearance self-esteem, and body size dissatisfaction with low global self-worth and low appearance self-esteem in children 8 and older. Appearance self-esteem but not global self-worth was lower in girls than boys. Parental perception of child's size as heavier than average was associated with low child appearance self-esteem. Heavier children also had more parental report of behavior and psychosocial problems, but their scores were in the nonclinical range. Child skin tone dissatisfaction was associated with low global self-worth. Weight-related peer teasing was associated with low self-esteem. The relationship between obesity and self-esteem in African American children depends upon age, gender, and children's experiences with teasing and parental evaluation of their size. Other factors, like skin tone satisfaction, contribute to a child's sense of self-worth.

The Cultural Relevance of Mindfulness Meditation as a Health Intervention for African Americans

Science.gov (United States)

Woods-Giscombé, Cheryl L.; Gaylord, Susan A.

2014-01-01

African Americans experience a disproportionate rate of stress-related health conditions compared to European Americans. Mindfulness meditation has been shown to be effective for managing stress and various stress-related health conditions. This study explored the cultural relevance of mindfulness meditation training for African Americans adults. Fifteen African American adults with past or current experience with mindfulness meditation training were interviewed. Participants felt that mindfulness meditation helped them with enhanced stress management, direct health improvement, and enhanced self-awareness and purposefulness. They felt that they would recommend it and that other African Americans would be open to the practice but suggested that its presentation may need to be adapted. They suggested emphasizing the health benefits, connecting it to familiar spiritual ideology and cultural practices, supplementing the reading material with African American writers, increasing communication (education, instructor availability, “buddy system,” etc.), and including African Americans as instructors and participants. By implementing minor adaptations that enhance cultural relevance, mindfulness meditation can be a beneficial therapeutic intervention for this population. PMID:24442592

Population Genomics of sub-saharan Drosophila melanogaster: African diversity and non-African admixture.

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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

Population Genomics of Sub-Saharan Drosophila melanogaster: African Diversity and Non-African Admixture

Science.gov (United States)

Pool, John E.; Corbett-Detig, Russell B.; Sugino, Ryuichi P.; Stevens, Kristian A.; Cardeno, Charis M.; Crepeau, Marc W.; Duchen, Pablo; Emerson, J. J.; Saelao, Perot; Begun, David J.; Langley, Charles H.

2012-01-01

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 FST were found to be enriched in genomic regions of locally elevated cosmopolitan

The role of African buffalos (Syncerus caffer) in the maintenance of foot-and-mouth disease in Uganda

DEFF Research Database (Denmark)

Ayebazibwe, C.; Mwiine, F. N.; Tjørnehøj, Kirsten

2010-01-01

(Alcelaphus buselaphus) and 5 waterbucks (Kobus ellipsiprymnus) from four major National Parks in Uganda between 2005 and 2008. Serum samples were screened to detect antibodies against foot-and-mouth disease virus (FMDV) non-structural proteins (NSP) using the Ceditest FMDV NS ELISA. Solid Phase Blocking......Background To study the role of African buffalos (Syncerus caffer) in the maintenance of foot-and-mouth disease in Uganda, serum samples were collected from 207 African buffalos, 21 impalas (Aepyceros melampus), 1 giraffe (Giraffa camelopardalis), 1 common eland (Taurotragus oryx), 7 hartebeests...... ELISAs (SPBE) were used to determine the serotype-specificity of antibodies against the seven serotypes of FMDV among the positive samples. Virus isolation and sequencing were undertaken to identify circulating viruses and determine relatedness between them. Results Among the buffalo samples tested, 85...

Adaptive selection on bracovirus genomes drives the specialization of Cotesia parasitoid wasps.

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Séverine Jancek

Full Text Available The geographic mosaic of coevolution predicts parasite virulence should be locally adapted to the host community. Cotesia parasitoid wasps adapt to local lepidopteran species possibly through their symbiotic bracovirus. The virus, essential for the parasitism success, is at the heart of the complex coevolutionary relationship linking the wasps and their hosts. The large segmented genome contained in the virus particles encodes virulence genes involved in host immune and developmental suppression. Coevolutionary arms race should result in the positive selection of particular beneficial alleles. To understand the global role of bracoviruses in the local adaptation or specialization of parasitoid wasps to their hosts, we studied the molecular evolution of four bracoviruses associated with wasps of the genus Cotesia, including C congregata, C vestalis and new data and annotation on two ecologically differentiated populations of C sesamie, Kitale and Mombasa. Paired orthologs analyses revealed more genes under positive selection when comparing the two C sesamiae bracoviruses belonging to the same species, and more genes under strong evolutionary constraint between species. Furthermore branch-site evolutionary models showed that 17 genes, out of the 54 currently available shared by the four bracoviruses, harboured sites under positive selection including: the histone H4-like, a C-type lectin, two ep1-like, ep2, a viral ankyrin, CrV1, a ben-domain, a Serine-rich, and eight unknown genes. Lastly the phylogenetic analyses of the histone, ep2 and CrV1 genes in different African C sesamiae populations showed that each gene described differently the individual relationships. In particular we found recombination had happened between the ep2 and CrV1 genes, which are localized 37.5 kb apart on the wasp chromosomes. Involved in multidirectional coevolutionary interactions, C sesamiae wasps rely on different bracovirus mediated molecular pathways to overcome

Hepatitis C Virus Infection In Nigerianswith Diabetesmellitus ...

African Journals Online (AJOL)

Background/Aims: Studies from mainly Caucasian populations have shown epidemiological evidence of an association between diabetes mellitus and Hepatitis C virus (HCV) infection. The aim of this study was to determine whether any such association exists in a black African population with diabetes mellitus. Method: ...

A brief history of the discovery of natural simian immunodeficiency virus (SIV) infections in captive sooty mangabey monkeys.

Science.gov (United States)

Gormus, Bobby J; Martin, Louis N; Baskin, Gary B

2004-01-01

Experimental leprosy studies using Mycobacterium leprae inoculum isolated from a sooty mangabey monkey (SMM) resulted in the accidental discovery that SMM's asymptomatically carry simian immunodeficiency virus (SIV) that is pathogenic in macaques. We showed that the SMM virus, SIVDelta, was antigenically related to SIVmac, which had been identified in macaques, and to the human immunodeficiency virus (HIV). Similar asymptomatic natural SIV infections had been reported in African green monkeys (AGM). Our results together with observations of others led us to propose that both SIVmac and SIVDelta originated in SMM and that SIV emerged in humans as a result of early African nonhuman primate SIV trans-species infections in humans.

High-throughput multiplex real-time PCR assay for the simultaneous quantification of DNA and RNA viruses infecting cassava plants.

Science.gov (United States)

Otti, G; Bouvaine, S; Kimata, B; Mkamillo, G; Kumar, P L; Tomlins, K; Maruthi, M N

2016-05-01

To develop a multiplex TaqMan-based real-time PCR assay (qPCR) for the simultaneous detection and quantification of both RNA and DNA viruses affecting cassava (Manihot esculenta) in eastern Africa. The diagnostic assay was developed for two RNA viruses; Cassava brown streak virus (CBSV) and Uganda cassava brown streak virus (UCBSV) and two predominant DNA viruses; African cassava mosaic virus (ACMV) and East African cassava mosaic virus (EACMV), which cause the economically important cassava brown streak disease (CBSD) and cassava mosaic disease (CMD) respectively. Our method, developed by analysing PCR products of viruses, was highly sensitive to detect target viruses from very low quantities of 4-10 femtograms. Multiplexing did not diminish sensitivity or accuracy compared to uniplex alternatives. The assay reliably detected and quantified four cassava viruses in field samples where CBSV and UCBSV synergy was observed in majority of mixed-infected varieties. We have developed a high-throughput qPCR diagnostic assay capable of specific and sensitive quantification of predominant DNA and RNA viruses of cassava in eastern Africa. The qPCR methods are a great improvement on the existing methods and can be used for monitoring virus spread as well as for accurate evaluation of the cassava varieties for virus resistance. © 2016 The Society for Applied Microbiology.

Exploring Self-Efficacy and Locus of Control as Risk Factors in Sexual Decision Making for African American Women

Science.gov (United States)

Pimpleton, Asher M.

2012-01-01

Sexually transmitted diseases have reached epidemic proportions, especially among African Americans. However, African American women have emerged as being one of the hardest hit groups by the most fatal of sexually transmitted diseases--the Human Immunodeficiency Virus (HIV) and the Acquired Immune Deficiency Syndrome (AIDS). Although there has…

Emergence and Adaptation of a Novel Highly Pathogenic H7N9 Influenza Virus in Birds and Humans from a 2013 Human-Infecting Low-Pathogenic Ancestor.

Science.gov (United States)

Qi, Wenbao; Jia, Weixin; Liu, Di; Li, Jing; Bi, Yuhai; Xie, Shumin; Li, Bo; Hu, Tao; Du, Yingying; Xing, Li; Zhang, Jiahao; Zhang, Fuchun; Wei, Xiaoman; Eden, John-Sebastian; Li, Huanan; Tian, Huaiyu; Li, Wei; Su, Guanming; Lao, Guangjie; Xu, Chenggang; Xu, Bing; Liu, Wenjun; Zhang, Guihong; Ren, Tao; Holmes, Edward C; Cui, Jie; Shi, Weifeng; Gao, George F; Liao, Ming

2018-01-15

Since its emergence in 2013, the H7N9 low-pathogenic avian influenza virus (LPAIV) has been circulating in domestic poultry in China, causing five waves of human infections. A novel H7N9 highly pathogenic avian influenza virus (HPAIV) variant possessing multiple basic amino acids at the cleavage site of the hemagglutinin (HA) protein was first reported in two cases of human infection in January 2017. More seriously, those novel H7N9 HPAIV variants have been transmitted and caused outbreaks on poultry farms in eight provinces in China. Herein, we demonstrate the presence of three different amino acid motifs at the cleavage sites of these HPAIV variants which were isolated from chickens and humans and likely evolved from the preexisting LPAIVs. Animal experiments showed that these novel H7N9 HPAIV variants are both highly pathogenic in chickens and lethal to mice. Notably, human-origin viruses were more pathogenic in mice than avian viruses, and the mutations in the PB2 gene associated with adaptation to mammals (E627K, A588V, and D701N) were identified by next-generation sequencing (NGS) and Sanger sequencing of the isolates from infected mice. No polymorphisms in the key amino acid substitutions of PB2 and HA in isolates from infected chicken lungs were detected by NGS. In sum, these results highlight the high degree of pathogenicity and the valid transmissibility of this new H7N9 variant in chickens and the quick adaptation of this new H7N9 variant to mammals, so the risk should be evaluated and more attention should be paid to this variant. IMPORTANCE Due to the recent increased numbers of zoonotic infections in poultry and persistent human infections in China, influenza A(H7N9) virus has remained a public health threat. Most of the influenza A(H7N9) viruses reported previously have been of low pathogenicity. Now, these novel H7N9 HPAIV variants have caused human infections in three provinces and outbreaks on poultry farms in eight provinces in China. We analyzed

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.

A new "American" subgroup of African-lineage Chikungunya virus detected in and isolated from mosquitoes collected in Haiti, 2016.

Science.gov (United States)

White, Sarah Keller; Mavian, Carla; Salemi, Marco; Morris, John Glenn; Elbadry, Maha A; Okech, Bernard A; Lednicky, John A; Dunford, James C

2018-01-01

As part of on-going arboviral surveillance activity in a semi-rural region in Haiti, Chikungunya virus (CHIKV)-positive mosquito pools were identified in 2014 (the peak of the Caribbean Asian-clade epidemic), and again in 2016 by RT-PCR. In 2014, CHIKV was only identified in Aedes aegypti (11 positive pools/124 screened). In contrast, in sampling in 2016, CHIKV was not identified in Ae. aegypti, but, rather, in (a) a female Aedes albopictus pool, and (b) a female Culex quinquefasciatus pool. Genomic sequence analyses indicated that the CHIKV viruses in the 2016 mosquito pools were from the East-Central-South African (ECSA) lineage, rather than the Asian lineage. In phylogenetic studies, these ECSA lineage strains form a new ECSA subgroup (subgroup IIa) together with Brazilian ECSA lineage strains from an isolated human outbreak in 2014, and a mosquito pool in 2016. Additional analyses date the most recent common ancestor of the ECSA IIa subgroup around May 2007, and the 2016 Haitian CHIKV genomes around December 2015. Known CHIKV mutations associated with improved Ae. albopictus vector competence were not identified. Isolation of this newly identified lineage from Ae. albopictus is of concern, as this vector has a broader geographic range than Ae. aegypti, especially in temperate areas of North America, and stresses the importance for continued vector surveillance.

Towards adaptive approaches to management of the South African ...

African Journals Online (AJOL)

The South African abalone Haliotis midae resource is widely perceived as being under threat of overexploitation as a result of increased poaching. In this paper, reservations are expressed about using catch per unit effort as the sole index of abundance when assessing this fishery, particularly because of the highly ...

Adaptation and the Individual Talent: An Intertextual Reading of ...

African Journals Online (AJOL)

A substantial amount of African dramatic works are adapted diversely from those of older Classical, Elizabethan, Modern and even African playwrights. This reveals that the writers admit to being influenced by those playwrights yet elements of their own creative imagination are noticeable in the plays. These creative ...

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

Directory of Open Access Journals (Sweden)

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.

A South African Romeo and Juliet : gender identity in Minky ...

African Journals Online (AJOL)

This article examines how gender identity is represented in a filmic adaptation of Shakespeare's play text Romeo and Juliet within South Africa's postcolonial context, thereby positioning identity politics as crucial in the decolonial project. This article focuses on Minky Schlesinger's South African adaptation of Romeo and ...

Identification of a divergent genotype of equine arteritis virus from South American donkeys.

Science.gov (United States)

Rivas, J; Neira, V; Mena, J; Brito, B; Garcia, A; Gutierrez, C; Sandoval, D; Ortega, R

2017-12-01

A novel equine arteritis virus (EAV) was isolated and sequenced from feral donkeys in Chile. Phylogenetic analysis indicates that the new virus and South African asinine strains diverged at least 100 years from equine EAV strains. The results indicate that asinine strains belonged to a different EAV genotype. © 2017 Blackwell Verlag GmbH.

The Prevalence of Human Immunodeficiency Virus Infection among ...

African Journals Online (AJOL)

AJRH Managing Editor

Agboghoroma et al. HIV Infection Diagnosed in Women in Labour. African Journal of Reproductive Health September 2015; 19 (3):137. ORIGINAL RESEARCH ARTICLE. The Prevalence of Human Immunodeficiency Virus Infection among. Pregnant Women in Labour with Unknown Status and those with. Negative status ...

Pock forming ability of fowl pox virus isolated from layer chicken and its adaptation in chicken embryo fibroblast cell culture.

Science.gov (United States)

Gilhare, Varsha Rani; Hirpurkar, S D; Kumar, Ashish; Naik, Surendra Kumar; Sahu, Tarini

2015-03-01

The objective of the present study was to examine pock forming ability of field strain and vaccine strain of fowl pox virus (FPV) in chorioallantoic membrane (CAM) of embryonated chicken eggs and its adaptation in chicken embryo fibroblast (CEF) cell culture. Dry scabs were collected from 25 affected birds in glycerin-saline and preserved at 4°C until processed. Virus was isolated in 10-day-old embryonated chicken eggs by dropped CAM method. The identity of the virus is confirmed by clinical findings of affected birds, pock morphology and histopathology of infected CAM. In addition one field isolate and vaccine strain of FPV was adapted to CEF cell culture. CEF cell culture was prepared from 9-day-old embryonated chicken eggs. Clinical symptoms observed in affected birds include pox lesion on comb, wattle, eyelids and legs, no internal lesions were observed. All field isolates produced similar findings in CAM. Pocks produced by field isolates ranged from 3 mm to 5 mm at the third passage while initial passages edematous thickening and necrosis of CAM was observed. Pocks formed by lyophilized strain were ranges from 0.5 mm to 2.5 mm in diameter scattered all over the membrane at the first passage. Intra-cytoplasmic inclusion bodies are found on histopathology of CAM. At third passage level, the CEF inoculated with FPV showed characteristic cytopathic effect (CPE) included aggregation of cells, syncytia and plaque formation. FPV field isolates and vaccine strain produced distinct pock lesions on CAMs. Infected CAM showed intracytoplasmic inclusion bodies. The CEF inoculated with FPV field isolate as well as a vaccine strain showed characteristic CPE at third passage level.

Epidemiological patterns of human immunodeficiency virus and ...

African Journals Online (AJOL)

There is no doubt that the greatest health problem threatening the human race these times is the HIV/AIDS pandemic. The greatest burden of this scourge is in sub-saharan African. This has undoubtedly increased the incidence of opportunistic infection like herpes simplex virus infection. This study investigated the ...

Ebola Virus Diseases | Elisha | African Journal of Clinical and ...

African Journals Online (AJOL)

African Journal of Clinical and Experimental Microbiology ... The current outbreak and a single case reported in 1994 in Ivory Coast are the only two outbreaks in West Africa (7). However, the current outbreak, which stared in Guinea (Bissau) in March 2014, remains the deadliest today and the epidemic is still ongoing.

Interferon alpha inhibits viral replication of a live-attenuated porcine reproductive and respiratory syndrome virus vaccine preventing development of an adaptive immune response in swine

Science.gov (United States)

Type I interferons, such as interferon alpha (IFNa), contribute to innate antiviral immunity by promoting production of antiviral mediators and are also involved in promoting an adaptive immune response. Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most devastating and c...

Four-segmented Rift Valley fever virus-based vaccines can be applied safely in ewes during pregnancy

NARCIS (Netherlands)

Wichgers Schreur, Paul J.; Keulen, van Lucien; Kant-Eenbergen, Jet; Kortekaas, Jeroen

2017-01-01

Rift Valley fever virus (RVFV) causes severe and recurrent outbreaks on the African continent and the Arabian Peninsula and continues to expand its habitat. This mosquito-borne virus, belonging to the genus Phlebovirus of the family Bunyaviridae contains a tri-segmented negative-strand RNA

Influence of social experiences in shaping perceptions of the Ebola virus among African residents of Hong Kong during the 2014 outbreak: a qualitative study.

Science.gov (United States)

Siu, Judy Yuen-man

2015-10-05

The outbreak of Ebola virus disease (EVD) in Africa in 2014 attracted worldwide attention. Because of the high mortality rate, marginalised social groups are vulnerable to disease-associated stigmatisation and discrimination, according to the literature. In Hong Kong, ethnic minorities such as Africans are often disadvantaged groups because of their low position in the social hierarchy. In 2011, approximately 1700 Africans were residing in Hong Kong. Their overseas experiences during the EVD outbreak were not well documented. Therefore, this study investigated the EVD-associated stigmatisation experiences of African residents of Hong Kong with chronic illnesses, and how these experiences shaped their perceptions of EVD. A qualitative design with 30 in-depth semistructured interviews was conducted with chronically ill African residents of Hong Kong. The interview data showed that the sampled Africans often experienced stigmatisation in their workplaces and in the community during the EVD outbreak. Their experiences of EVD-associated stigma were correlated to the embedded social and cultural values regarding ethnic minorities in Hong Kong. These experiences of being stigmatised shaped the perceptions of the Africans of EVD, leading them to view EVD as shameful and horrifying. They also perceived EVD as retribution and was introduced by Westerners. The participants' perceptions of EVD influenced their responses to and behaviour towards EVD, which may have posed potential threats to Hong Kong's public health. The EVD outbreak was not the only cause of the participants' stigmatisation; rather, their EVD-associated experiences were a continuation and manifestation of the embedded social and cultural values regarding ethnic minorities in Hong Kong. The experiences of being stigmatised shaped the participants' perceptions of EVD. Because of their marginalised social position and isolation from the main community, the participants had extremely limited access to reliable

Ebola virus: current and future perspectives.

Science.gov (United States)

Jadav, Surender Singh; Kumar, Anoop; Ahsan, Mohamed Jawed; Jayaprakash, Venkatesan

2015-01-01

The present outbreak associated with Ebola disease in Western countries of the African continent which is believed to be one of the massive eruptions caused by the Ebola viral infections. In the present scenario ebola has been transmitted to the European and American regions through the travelers from wide spread countries like Guinea, Liberia, Sierra Leone and Nigeria. The viral disease is spreading through the contact in any form by the infected persons or patients and creating huge risks to the mortals. The symptoms related to ebola virus are often highly pathogenic; about 70-80% of death cases are reported due to critical hemorrhagic fever. Early in infection, ebola virus infects macrophages and endothelial cells. It mainly produces a Viral Protein 24 (eVP24) which prevents interferon-based signals which are important for destruction of viruses. How ebola virus manipulates the function of the immune system is still unclear. Due to lack of this knowledge, no approved treatment is available. In this review, we have tried to compile the epidemiology, pathogenesis and treatment of ebola virus infection. The promising ligands against ebola virus have been also discussed which will be helpful for researchers to design drugs for the treatment of ebola virus disease.

Quantitative trait loci for resistance to maize streak virus disease in ...

African Journals Online (AJOL)

STORAGESEVER

2008-07-18

Jul 18, 2008 ... African Journal of Biotechnology Vol. ... development ... Biotechnology Center, Kenya Agricultural Research Institute, P.O. Box 58711-00200, Nairobi, ... Maize streak virus disease is an important disease of maize in Kenya.

Analyses of Tissue Culture Adaptation of Human Herpesvirus-6A by Whole Genome Deep Sequencing Redefines the Reference Sequence and Identifies Virus Entry Complex Changes.

Science.gov (United States)

Tweedy, Joshua G; Escriva, Eric; Topf, Maya; Gompels, Ursula A

2017-12-31

Tissue-culture adaptation of viruses can modulate infection. Laboratory passage and bacterial artificial chromosome (BAC)mid cloning of human cytomegalovirus, HCMV, resulted in genomic deletions and rearrangements altering genes encoding the virus entry complex, which affected cellular tropism, virulence, and vaccine development. Here, we analyse these effects on the reference genome for related betaherpesviruses, Roseolovirus, human herpesvirus 6A (HHV-6A) strain U1102. This virus is also naturally "cloned" by germline subtelomeric chromosomal-integration in approximately 1% of human populations, and accurate references are key to understanding pathological relationships between exogenous and endogenous virus. Using whole genome next-generation deep-sequencing Illumina-based methods, we compared the original isolate to tissue-culture passaged and the BACmid-cloned virus. This re-defined the reference genome showing 32 corrections and 5 polymorphisms. Furthermore, minor variant analyses of passaged and BACmid virus identified emerging populations of a further 32 single nucleotide polymorphisms (SNPs) in 10 loci, half non-synonymous indicating cell-culture selection. Analyses of the BAC-virus genome showed deletion of the BAC cassette via loxP recombination removing green fluorescent protein (GFP)-based selection. As shown for HCMV culture effects, select HHV-6A SNPs mapped to genes encoding mediators of virus cellular entry, including virus envelope glycoprotein genes gB and the gH/gL complex. Comparative models suggest stabilisation of the post-fusion conformation. These SNPs are essential to consider in vaccine-design, antimicrobial-resistance, and pathogenesis.

Community Based Adaptation to Climate Change in Africa | IDRC ...

International Development Research Centre (IDRC) Digital Library (Canada)

First General Meeting : the Adaptation Network; We're Up to the Climate Challenge!, Kirstenbosch Botanical Gardens, Cape Town, 4 November 2009. Download PDF. Reports. South African National Networking Meeting on Climate Change Adaptation, the Airport Grand Hotel, Johannesburg, 18 June 2009. Download PDF ...

Adaptation of cotton cultivars | Wondimu | African Crop Science ...

African Journals Online (AJOL)

For each cultivar a linear regression of yield on the mean yield of all cultivars for each year was computed to measure cultivar adaptation. The cultivars with the highest mean yield exhibited a similar degree of adaptation to different environments with regression coefficient close to 1.0. For example, the breeding lines, Acala ...

An infectious bat-derived chimeric influenza virus harbouring the entry machinery of an influenza A virus.

Science.gov (United States)

Juozapaitis, Mindaugas; Aguiar Moreira, Étori; Mena, Ignacio; Giese, Sebastian; Riegger, David; Pohlmann, Anne; Höper, Dirk; Zimmer, Gert; Beer, Martin; García-Sastre, Adolfo; Schwemmle, Martin

2014-07-23

In 2012, the complete genomic sequence of a new and potentially harmful influenza A-like virus from bats (H17N10) was identified. However, infectious influenza virus was neither isolated from infected bats nor reconstituted, impeding further characterization of this virus. Here we show the generation of an infectious chimeric virus containing six out of the eight bat virus genes, with the remaining two genes encoding the haemagglutinin and neuraminidase proteins of a prototypic influenza A virus. This engineered virus replicates well in a broad range of mammalian cell cultures, human primary airway epithelial cells and mice, but poorly in avian cells and chicken embryos without further adaptation. Importantly, the bat chimeric virus is unable to reassort with other influenza A viruses. Although our data do not exclude the possibility of zoonotic transmission of bat influenza viruses into the human population, they indicate that multiple barriers exist that makes this an unlikely event.

Human whole body cold adaptation.

NARCIS (Netherlands)

Daanen, Hein A.M.; Van Marken Lichtenbelt, Wouter D.

2016-01-01

Reviews on whole body human cold adaptation generally do not distinguish between population studies and dedicated acclimation studies, leading to confusing results. Population studies show that indigenous black Africans have reduced shivering thermogenesis in the cold and poor cold induced

Broadly Neutralizing Activity of Zika Virus-Immune Sera Identifies a Single Viral Serotype

Directory of Open Access Journals (Sweden)

Kimberly A. Dowd

2016-08-01

Full Text Available Recent epidemics of Zika virus (ZIKV have been associated with congenital malformation during pregnancy and Guillain-Barré syndrome. There are two ZIKV lineages (African and Asian that share >95% amino acid identity. Little is known regarding the ability of neutralizing antibodies elicited against one lineage to protect against the other. We investigated the breadth of the neutralizing antibody response following ZIKV infection by measuring the sensitivity of six ZIKV strains to neutralization by ZIKV-confirmed convalescent human serum or plasma samples. Contemporary Asian and early African ZIKV strains were similarly sensitive to neutralization regardless of the cellular source of virus. Furthermore, mouse immune serum generated after infection with African or Asian ZIKV strains was capable of neutralizing homologous and heterologous ZIKV strains equivalently. Because our study only defines a single ZIKV serotype, vaccine candidates eliciting robust neutralizing antibody responses should inhibit infection of both ZIKV lineages, including strains circulating in the Americas.

Top 10 plant viruses in molecular plant pathology.

Science.gov (United States)

Scholthof, Karen-Beth G; Adkins, Scott; Czosnek, Henryk; Palukaitis, Peter; Jacquot, Emmanuel; Hohn, Thomas; Hohn, Barbara; Saunders, Keith; Candresse, Thierry; Ahlquist, Paul; Hemenway, Cynthia; Foster, Gary D

2011-12-01

Many scientists, if not all, feel that their particular plant virus should appear in any list of the most important plant viruses. However, to our knowledge, no such list exists. The aim of this review was to survey all plant virologists with an association with Molecular Plant Pathology and ask them to nominate which plant viruses they would place in a 'Top 10' based on scientific/economic importance. The survey generated more than 250 votes from the international community, and allowed the generation of a Top 10 plant virus list for Molecular Plant Pathology. The Top 10 list includes, in rank order, (1) Tobacco mosaic virus, (2) Tomato spotted wilt virus, (3) Tomato yellow leaf curl virus, (4) Cucumber mosaic virus, (5) Potato virus Y, (6) Cauliflower mosaic virus, (7) African cassava mosaic virus, (8) Plum pox virus, (9) Brome mosaic virus and (10) Potato virus X, with honourable mentions for viruses just missing out on the Top 10, including Citrus tristeza virus, Barley yellow dwarf virus, Potato leafroll virus and Tomato bushy stunt virus. This review article presents a short review on each virus of the Top 10 list and its importance, with the intent of initiating discussion and debate amongst the plant virology community, as well as laying down a benchmark, as it will be interesting to see in future years how perceptions change and which viruses enter and leave the Top 10. © 2011 The Authors. Molecular Plant Pathology © 2011 BSPP and Blackwell Publishing Ltd.

The combined risks of reduced or increased function variants in cell death pathway genes differentially influence cervical cancer risk and herpes simplex virus type 2 infection among black Africans and the Mixed Ancestry population of South Africa

International Nuclear Information System (INIS)

Chattopadhyay, Koushik; Williamson, Anna-Lise; Hazra, Annapurna; Dandara, Collet

2015-01-01

Cervical cancer is one of the most important cancers worldwide with a high incident and mortality rate and is caused by the human papilloma virus (HPV). Among sexually active women who get infected with human papillomavirus (HPV), a small fraction progresses to cervical cancer disease pointing to possible roles of additional risk factors in development of the disease which include host genetic factors and other infections such as HSV-2. Since cellular apoptosis plays a role in controlling the spread of virus-infections in cells, gene variants altering the function of proteins involved in cell death pathways might be associated with the clearing of virus infections. Activity altering polymorphisms in FasR (−1377G > A and -670A > G), FasL (−844 T > C) and CASP8 (−652 6 N ins/del) genes have been shown to alter the mechanism of apoptosis by modifying the level of expression of their correspondent proteins. In the present study, we set out to investigate the combined risks of CASP8, FasR, and FasL polymorphisms in cervical cancer, pre-cancerous lesions, HPV infection and HSV-2 infection. Participants were 442 South African women of black African and mixed-ancestry origin with invasive cervical cancer and 278 control women matched by age, ethnicity and domicile status. FasR and FasL polymorphisms were genotyped by TaqMan and CASP8 polymorphism by PCR-RFLP. The results were analysed with R using haplo.stats software version 1.5.2. CASP8 -652 6 N del + FasR-670A was associated with a reduced risk (P = 0.019, Combined Polymorphism Score (CPS) = −2.34) and CASP8 -652 6 N ins + FasR-1377G was associated with a marginal increased risk (P = 0.047, CPS = 1.99) of cervical cancer among black Africans. When compared within the control group, CASP8 -652 6 N ins + FasR-1377A showed a reduced risk (P = 0.023, CPS = −2.28) of HSV-2 infection in both black African and mixed-ancestry population. Our results show that the combined risks of variants in cell death pathway genes

The combined risks of reduced or increased function variants in cell death pathway genes differentially influence cervical cancer risk and herpes simplex virus type 2 infection among black Africans and the Mixed Ancestry population of South Africa.

Science.gov (United States)

Chattopadhyay, Koushik; Williamson, Anna-Lise; Hazra, Annapurna; Dandara, Collet

2015-10-12

Cervical cancer is one of the most important cancers worldwide with a high incident and mortality rate and is caused by the human papilloma virus (HPV). Among sexually active women who get infected with human papillomavirus (HPV), a small fraction progresses to cervical cancer disease pointing to possible roles of additional risk factors in development of the disease which include host genetic factors and other infections such as HSV-2. Since cellular apoptosis plays a role in controlling the spread of virus-infections in cells, gene variants altering the function of proteins involved in cell death pathways might be associated with the clearing of virus infections. Activity altering polymorphisms in FasR (-1377G > A and -670A > G), FasL (-844 T > C) and CASP8 (-652 6 N ins/del) genes have been shown to alter the mechanism of apoptosis by modifying the level of expression of their correspondent proteins. In the present study, we set out to investigate the combined risks of CASP8, FasR, and FasL polymorphisms in cervical cancer, pre-cancerous lesions, HPV infection and HSV-2 infection. Participants were 442 South African women of black African and mixed-ancestry origin with invasive cervical cancer and 278 control women matched by age, ethnicity and domicile status. FasR and FasL polymorphisms were genotyped by TaqMan and CASP8 polymorphism by PCR-RFLP. The results were analysed with R using haplo.stats software version 1.5.2. CASP8 -652 6 N del + FasR-670A was associated with a reduced risk (P = 0.019, Combined Polymorphism Score (CPS) = -2.34) and CASP8 -652 6 N ins + FasR-1377G was associated with a marginal increased risk (P = 0.047, CPS = 1.99) of cervical cancer among black Africans. When compared within the control group, CASP8 -652 6 N ins + FasR-1377A showed a reduced risk (P = 0.023, CPS = -2.28) of HSV-2 infection in both black African and mixed-ancestry population. Our results show that the combined risks of

Human whole body cold adaptation.

OpenAIRE

Daanen, Hein A.M.; Van Marken Lichtenbelt, Wouter D.

2016-01-01

ABSTRACT Reviews on whole body human cold adaptation generally do not distinguish between population studies and dedicated acclimation studies, leading to confusing results. Population studies show that indigenous black Africans have reduced shivering thermogenesis in the cold and poor cold induced vasodilation in fingers and toes compared to Caucasians and Inuit. About 40,000?y after humans left Africa, natives in cold terrestrial areas seems to have developed not only behavioral adaptations...

Ju/'hoansi Adaptations to a Cash Economy | McCall | African ...

African Journals Online (AJOL)

African Sociological Review / Revue Africaine de Sociologie. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 4, No 1 (2000) >. Log in or Register to get access to full text downloads.

Epidemiology and pathogesis of human immunodifiency virus(HIV ...

African Journals Online (AJOL)

Epidemiology and pathogesis of human immunodifiency virus(HIV) related heart disease: A review. MU Sani, BN Okeahialam. Abstract. No Abstract. Nigerian Journal of Medicine Vol. 14(3) 2005: 255-260. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African ...

Monitoring and Evaluation Toolkit for Climate Change Adaptation ...

International Development Research Centre (IDRC) Digital Library (Canada)

Many African countries, regions and organizations are making plans for climate change adaptation. If such plans are to be effective, they will need to be monitored and evaluated on an ongoing basis. This grant will support the integration of monitoring and evaluation (M&E) in climate change adaptation initiatives by ...

Strengthening African Union for African Integration: An African ...

African Journals Online (AJOL)

Log in or Register to get access to full text downloads. ... in the international state system and seek for African initiative in solving African problems. ... of the African Union by examining the efforts of African Leaders towards African integration, ...

Convergence of gut microbiotas in the adaptive radiations of African cichlid fishes.

Science.gov (United States)

Baldo, Laura; Pretus, Joan Lluís; Riera, Joan Lluís; Musilova, Zuzana; Bitja Nyom, Arnold Roger; Salzburger, Walter

2017-09-01

Ecoevolutionary dynamics of the gut microbiota at the macroscale level, that is, in across-species comparisons, are largely driven by ecological variables and host genotype. The repeated explosive radiations of African cichlid fishes in distinct lakes, following a dietary diversification in a context of reduced genetic diversity, provide a natural setup to explore convergence, divergence and repeatability in patterns of microbiota dynamics as a function of the host diet, phylogeny and environment. Here we characterized by 16S rRNA amplicon sequencing the gut microbiota of 29 cichlid species from two distinct lakes/radiations (Tanganyika and Barombi Mbo) and across a broad dietary and phylogenetic range. Within each lake, a significant deviation between a carnivorous and herbivorous lifestyle was found. Herbivore species were characterized by an increased bacterial taxonomic and functional diversity and converged in key compositional and functional community aspects. Despite a significant lake effect on the microbiota structure, this process has occurred with remarkable parallels in the two lakes. A metabolic signature most likely explains this trend, as indicated by a significant enrichment in herbivores/omnivores of bacterial taxa and functions associated with fiber degradation and detoxification of plant chemical compounds. Overall, compositional and functional aspects of the gut microbiota individually and altogether validate and predict main cichlid dietary habits, suggesting a fundamental role of gut bacteria in cichlid niche expansion and adaptation.

The relationship of self-esteem and risky sexual behaviors in young African-American women.

Science.gov (United States)

Pittiglio, Laura; Jackson, Frances; Florio, Ann

2012-07-01

In the United States, African-American women are at disproportionate risk for contracting human immunodeficiency virus (HIV) and face the most profound burden of HIV infection. Reducing the risk of exposure to HIV in African-American women is a priority for health-care providers. The findings of this study add to the existing literature by examining the relationship of self-esteem and risky sexual behaviors in young African-American women. Lack of self-esteem was one of the themes that emerged from a larger study that investigated how African-American women define HIV-risky behavior. In the current study, quantitative and qualitative data were collected from a convenience sample of 33 African-American women (N = 33) from three metropolitan regions within Michigan. Findings highlight the importance of understanding the relationship between self-esteem and its implications for HIV/sexually transmitted disease (STD) prevention.

Syrian Hamster as an Animal Model for the Study of Human Influenza Virus Infection.

Science.gov (United States)

Iwatsuki-Horimoto, Kiyoko; Nakajima, Noriko; Ichiko, Yurie; Sakai-Tagawa, Yuko; Noda, Takeshi; Hasegawa, Hideki; Kawaoka, Yoshihiro

2018-02-15

Ferrets and mice are frequently used as animal models for influenza research. However, ferrets are demanding in terms of housing space and handling, whereas mice are not naturally susceptible to infection with human influenza A or B viruses. Therefore, prior adaptation of human viruses is required for their use in mice. In addition, there are no mouse-adapted variants of the recent H3N2 viruses, because these viruses do not replicate well in mice. In this study, we investigated the susceptibility of Syrian hamsters to influenza viruses with a view to using the hamster model as an alternative to the mouse model. We found that hamsters are sensitive to influenza viruses, including the recent H3N2 viruses, without adaptation. Although the hamsters did not show weight loss or clinical signs of H3N2 virus infection, we observed pathogenic effects in the respiratory tracts of the infected animals. All of the H3N2 viruses tested replicated in the respiratory organs of the hamsters, and some of them were detected in the nasal washes of infected animals. Moreover, a 2009 pandemic (pdm09) virus and a seasonal H1N1 virus, as well as one of the two H3N2 viruses, but not a type B virus, were transmissible by the airborne route in these hamsters. Hamsters thus have the potential to be a small-animal model for the study of influenza virus infection, including studies of the pathogenicity of H3N2 viruses and other strains, as well as for use in H1N1 virus transmission studies. IMPORTANCE We found that Syrian hamsters are susceptible to human influenza viruses, including the recent H3N2 viruses, without adaptation. We also found that a pdm09 virus and a seasonal H1N1 virus, as well as one of the H3N2 viruses, but not a type B virus tested, are transmitted by the airborne route in these hamsters. Syrian hamsters thus have the potential to be used as a small-animal model for the study of human influenza viruses. Copyright © 2018 American Society for Microbiology.

Molecular characterization of the African orthobunyavirus Ilesha virus

Czech Academy of Sciences Publication Activity Database

Pachler, K.; Růžek, Daniel; Nowotny, N.

2013-01-01

Roč. 20, DEC 2013 (2013), s. 124-130 ISSN 1567-1348 R&D Projects: GA ČR GAP502/11/2116 Grant - others:GA MŠk(CZ) ED0006/01/01 Institutional support: RVO:60077344 Keywords : Ilesha virus * Orthobunyavirus * Genome characterization * Phylogenetic analysis Subject RIV: EE - Microbiology, Virology Impact factor: 3.264, year: 2013

Recent advances on Ebola virus

Directory of Open Access Journals (Sweden)

Yasir Waheed

2017-02-01

Full Text Available The 2014–2015 Ebola epidemic in West Africa was the largest of its kind, with more than 11 000 deaths and 28 637 cases. The epidemic mobilized a coalition of countries from US to China, European Union, and African countries. The international community was not prepared to face this unprecedented epidemic. Numbers of research groups are working to find a potent vaccine against Ebola. Ebola virus has the ability to dodge the immune system either by blocking interferon production or by glycoprotein-based immune diversion. Individuals who survived from the Ebola virus are facing different health issues after the infection. The rate of miscarriage is also high in Ebola survivors while there are variable reports of the presence of Ebola virus in semen of Ebola survivors. There are many asymptomatic Ebola patients under consideration. West African countries lack the basic healthcare system, for which the actual number of deaths by the Ebola outbreak are much more than the deaths caused by the direct viral infection. The hospitals were empty due to fear and death of nurses and doctors. Millions of children missed the vaccine against measles. Hundreds of thousands of people could not get food. The Ebola epidemic also affected the mental health of people living in endemic countries. The families affected by Ebola are facing discrimination in the society. There is a dire need to adopt United Nations Sustainable Development Goal 3, which stresses to prepare ourselves to face any national or global health risk.

Evolutionary ecology of virus emergence.

Science.gov (United States)

Dennehy, John J

2017-02-01

The cross-species transmission of viruses into new host populations, termed virus emergence, is a significant issue in public health, agriculture, wildlife management, and related fields. Virus emergence requires overlap between host populations, alterations in virus genetics to permit infection of new hosts, and adaptation to novel hosts such that between-host transmission is sustainable, all of which are the purview of the fields of ecology and evolution. A firm understanding of the ecology of viruses and how they evolve is required for understanding how and why viruses emerge. In this paper, I address the evolutionary mechanisms of virus emergence and how they relate to virus ecology. I argue that, while virus acquisition of the ability to infect new hosts is not difficult, limited evolutionary trajectories to sustained virus between-host transmission and the combined effects of mutational meltdown, bottlenecking, demographic stochasticity, density dependence, and genetic erosion in ecological sinks limit most emergence events to dead-end spillover infections. Despite the relative rarity of pandemic emerging viruses, the potential of viruses to search evolutionary space and find means to spread epidemically and the consequences of pandemic viruses that do emerge necessitate sustained attention to virus research, surveillance, prophylaxis, and treatment. © 2016 New York Academy of Sciences.

Tomato Leaf Curl New Delhi Virus: An Emerging Virus Complex Threatening Vegetable and Fiber Crops

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Enrique Moriones

2017-09-01

Full Text Available The tomato leaf curl New Delhi virus (ToLCNDV (genus Begomovirus, family Geminiviridae represents an important constraint to tomato production, as it causes the most predominant and economically important disease affecting tomato in the Indian sub-continent. However, in recent years, ToLCNDV has been fast extending its host range and spreading to new geographical regions, including the Middle East and the western Mediterranean Basin. Extensive research on the genome structure, protein functions, molecular biology, and plant–virus interactions of ToLCNDV has been conducted in the last decade. Special emphasis has been given to gene silencing suppression ability in order to counteract host plant defense responses. The importance of the interaction with DNA alphasatellites and betasatellites in the biology of the virus has been demonstrated. ToLCNDV genetic variability has been analyzed, providing new insights into the taxonomy, host adaptation, and evolution of this virus. Recombination and pseudorecombination have been shown as motors of diversification and adaptive evolution. Important progress has also been made in control strategies to reduce disease damage. This review highlights these various achievements in the context of the previous knowledge of begomoviruses and their interactions with plants.

Exceptionally diverse morphotypes and genomes of crenarchaeal hyperthermophilic viruses

DEFF Research Database (Denmark)

Prangishvili, D; Garrett, R A

2004-01-01

and Rudiviridae. They all have double-stranded DNA genomes and infect hyperthermophilic crenarchaea of the orders Sulfolobales and Thermoproteales. Representatives of the different viral families share a few homologous ORFs (open reading frames). However, about 90% of all ORFs in the seven sequenced genomes show...... no significant matches to sequences in public databases. This suggests that these hyperthermophilic viruses have exceptional biochemical solutions for biological functions. Specific features of genome organization, as well as strategies for DNA replication, suggest that phylogenetic relationships exist between...... 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...

Differential sensitivity of bat cells to infection by enveloped RNA viruses: coronaviruses, paramyxoviruses, filoviruses, and influenza viruses.

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Markus Hoffmann

Full Text Available Bats (Chiroptera host major human pathogenic viruses including corona-, paramyxo, rhabdo- and filoviruses. We analyzed six different cell lines from either Yinpterochiroptera (including African flying foxes and a rhinolophid bat or Yangochiroptera (genera Carollia and Tadarida for susceptibility to infection by different enveloped RNA viruses. None of the cells were sensitive to infection by transmissible gastroenteritis virus (TGEV, a porcine coronavirus, or to infection mediated by the Spike (S protein of SARS-coronavirus (SARS-CoV incorporated into pseudotypes based on vesicular stomatitis virus (VSV. The resistance to infection was overcome if cells were transfected to express the respective cellular receptor, porcine aminopeptidase N for TGEV or angiotensin-converting enzyme 2 for SARS-CoV. VSV pseudotypes containing the S proteins of two bat SARS-related CoV (Bg08 and Rp3 were unable to infect any of the six tested bat cell lines. By contrast, viral pseudotypes containing the surface protein GP of Marburg virus from the family Filoviridae infected all six cell lines though at different efficiency. Notably, all cells were sensitive to infection by two paramyxoviruses (Sendai virus and bovine respiratory syncytial virus and three influenza viruses from different subtypes. These results indicate that bat cells are more resistant to infection by coronaviruses than to infection by paramyxoviruses, filoviruses and influenza viruses. Furthermore, these results show a receptor-dependent restriction of the infection of bat cells by CoV. The implications for the isolation of coronaviruses from bats are discussed.

Adaptation de collectivités africaines aux changements climatiques ...

International Development Research Centre (IDRC) Digital Library (Canada)

Rapports. First General Meeting : the Adaptation Network; We're Up to the Climate Challenge!, Kirstenbosch Botanical Gardens, Cape Town, 4 November 2009. Téléchargez le PDF. Rapports. South African National Networking Meeting on Climate Change Adaptation, the Airport Grand Hotel, Johannesburg, 18 June 2009.

Mobilizing local safety nets for enhanced adaptive capacity to ...

International Development Research Centre (IDRC) Digital Library (Canada)

2016-04-22

Apr 22, 2016 ... This brief resulted from two projects supported by the Climate Change Adaptation in Africa program: the research project Resilience and the African Smallholder : Enhancing the Capacity of Communities to Adapt to Climate Change and the mentoring project Promoting Participatory Action Research through ...

Zika Virus: An Emergent Neuropathological Agent

Science.gov (United States)

White, Martyn K.; Wollebo, Hassen S.; Beckham, J. David; Tyler, Kenneth L.; Khalili, Kamel

2016-01-01

The emergence of Zika virus in the Americas has followed a pattern that is familiar from earlier epidemics of other viruses, where a new disease is introduced into a human population and then spreads rapidly with important public health consequences. In the case of Zika virus, an accumulating body of recent evidence implicates the virus in the etiology of serious pathologies of the human nervous system, that is, the occurrence of microcephaly in neonates and Guillain–Barré syndrome in adults. Zika virus is an arbovirus (arthropod-borne virus) and a member of the family Flaviviridae, genus Flavivirus. Zika virions are enveloped and icosahedral, and contain a nonsegmented, single-stranded, positive-sense RNA genome, which encodes 3 structural and 7 nonstructural proteins that are expressed as a single polyprotein that undergoes cleavage. Zika genomic RNA replicates in the cytoplasm of infected host cells. Zika virus was first detected in 1947 in the blood of a febrile monkey in Uganda’s Zika Forest and in crushed suspensions of the Aedes mosquito, which is one of the vectors for Zika virus. The virus remained obscure, with a few human cases confined to Africa and Asia. There are two lineages of the Zika virus, African and Asian, with the Asian strain causing outbreaks in Micronesia in 2007 and French Polynesia in 2013–2014. From here, the virus spread to Brazil with the first report of autochthonous Zika transmission in the Americas in March 2015. The rapid advance of the virus in the Americas and its likely association with microcephaly and Guillain–Barré syndrome make Zika an urgent public health concern. PMID:27464346

Association of African Universities : Education and Research ...

International Development Research Centre (IDRC) Digital Library (Canada)

The Association of African Universities (AAU), headquartered in Accra, Ghana, is an ... The Association operates a number of programs and services for its members. ... IWRA/IDRC webinar on climate change and adaptive water management ... Eleven world-class research teams set to improve livestock vaccine ...

Acute Lung Injury Results from Innate Sensing of Viruses by an ER Stress Pathway

Directory of Open Access Journals (Sweden)

Eike R. Hrincius

2015-06-01

Full Text Available Incursions of new pathogenic viruses into humans from animal reservoirs are occurring with alarming frequency. The molecular underpinnings of immune recognition, host responses, and pathogenesis in this setting are poorly understood. We studied pandemic influenza viruses to determine the mechanism by which increasing glycosylation during evolution of surface proteins facilitates diminished pathogenicity in adapted viruses. ER stress during infection with poorly glycosylated pandemic strains activated the unfolded protein response, leading to inflammation, acute lung injury, and mortality. Seasonal strains or viruses engineered to mimic adapted viruses displaying excess glycans on the hemagglutinin did not cause ER stress, allowing preservation of the lungs and survival. We propose that ER stress resulting from recognition of non-adapted viruses is utilized to discriminate “non-self” at the level of protein processing and to activate immune responses, with unintended consequences on pathogenesis. Understanding this mechanism should improve strategies for treating acute lung injury from zoonotic viral infections.

Ebola virus - epidemiology, diagnosis, and control: threat to humans, lessons learnt, and preparedness plans - an update on its 40 year's journey.

Science.gov (United States)

Singh, Raj Kumar; Dhama, Kuldeep; Malik, Yashpal Singh; Ramakrishnan, Muthannan Andavar; Karthik, Kumaragurubaran; Khandia, Rekha; Tiwari, Ruchi; Munjal, Ashok; Saminathan, Mani; Sachan, Swati; Desingu, Perumal Arumugam; Kattoor, Jobin Jose; Iqbal, Hafiz M N; Joshi, Sunil Kumar

2017-12-01

Ebola virus (EBOV) is an extremely contagious pathogen and causes lethal hemorrhagic fever disease in man and animals. The recently occurred Ebola virus disease (EVD) outbreaks in the West African countries have categorized it as an international health concern. For the virus maintenance and transmission, the non-human primates and reservoir hosts like fruit bats have played a vital role. For curbing the disease timely, we need effective therapeutics/prophylactics, however, in the absence of any approved vaccine, timely diagnosis and monitoring of EBOV remains of utmost importance. The technologically advanced vaccines like a viral-vectored vaccine, DNA vaccine and virus-like particles are underway for testing against EBOV. In the absence of any effective control measure, the adaptation of high standards of biosecurity measures, strict sanitary and hygienic practices, strengthening of surveillance and monitoring systems, imposing appropriate quarantine checks and vigilance on trade, transport, and movement of visitors from EVD endemic countries remains the answer of choice for tackling the EBOV spread. Herein, we converse with the current scenario of EBOV giving due emphasis on animal and veterinary perspectives along with advances in diagnosis and control strategies to be adopted, lessons learned from the recent outbreaks and the global preparedness plans. To retrieve the evolutionary information, we have analyzed a total of 56 genome sequences of various EBOV species submitted between 1976 and 2016 in public databases.

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.

African Journal of Biotechnology - Vol 9, No 21 (2010)

African Journals Online (AJOL)

African Journal of Biotechnology. ... Genotype x Environment interaction for quality traits in durum wheat cultivars adapted to different ... Effects of genetically modified herbicide-tolerant (GMHT) rice on biodiversity of weed in paddy fields ...

Ebola virus (EBOV) infection: Therapeutic strategies.

Science.gov (United States)

De Clercq, Erik

2015-01-01

Within less than a year after its epidemic started (in December 2013) in Guinea, Ebola virus (EBOV), a member of the filoviridae, has spread over a number of West-African countries (Guinea, Sierra Leone and Liberia) and gained allures that have been unprecedented except by human immunodeficiency virus (HIV). Although EBOV is highly contagious and transmitted by direct contact with body fluids, it could be counteracted by the adequate chemoprophylactic and -therapeutic interventions: vaccines, antibodies, siRNAs (small interfering RNAs), interferons and chemical substances, i.e. neplanocin A derivatives (i.e. 3-deazaneplanocin A), BCX4430, favipiravir (T-705), endoplasmic reticulum (ER) α-glucosidase inhibitors and a variety of compounds that have been found to inhibit EBOV infection blocking viral entry or by a mode of action that still has to be resolved. Much has to be learned from the mechanism of action of the compounds active against VSV (vesicular stomatitis virus), a virus belonging to the rhabdoviridae, that in its mode of replication could be exemplary for the replication of filoviridae. Copyright © 2014 Elsevier Inc. All rights reserved.

Double-stranded-RNA-specific adenosine deaminase 1 (ADAR1) is proposed to contribute to the adaptation of equine infectious anemia virus from horses to donkeys.

Science.gov (United States)

Tang, Yan-Dong; Zhang, Xiang; Na, Lei; Wang, Xue-Feng; Fu, Li-Hua; Zhu, Chun-Hui; Wang, Xiaojun; Zhou, Jian-Hua

2016-10-01

Equine infectious anemia virus (EIAV) is a member of the genus Lentivirus of the family Retroviridae. Horses are the most susceptible equids to EIAV infection and are therefore the primary hosts of this virus. In contrast, infected donkeys do not develop clinically active equine infectious anemia (EIA). This phenomenon is similar to what has been observed with HIV-1, which fails to induce AIDS in non-human primates. Interestingly, Shen et al. developed a donkey-tropic pathogenic virus strain (EIAVDV117, DV117) by serially passaging a horse-tropic pathogenic strain, EIAVLN40 (LN40), in donkeys. LN40, which was generated by passaging a field isolate in horses, displayed enhanced virulence in horses but caused no clinical symptoms in donkeys. Infection with DV117 induced acute EIA in nearly 100 % of donkeys. Genomic analysis of DV117 revealed a significantly higher frequency of A-to-G substitutions when compared to LN40. Furthermore, detailed analysis of dinucleotide editing showed that A-to-G mutations had a preference for 5'TpA and 5'ApA. These results strongly implicated the activity of the adenosine deaminase, ADAR1, in this type of mutation. Further investigation demonstrated that overexpression of donkey ADAR1 increased A-to-G mutations within the genome of EIAV. Together with our previous finding that multiple mutations in multiple genes are generated in DV117 during its adaptation from horses to donkeys, the present study suggests that ADAR1-induced A-to-G mutations occur during virus adaption to related new hosts contributing to the alteration of EIAV host tropism.

Hepatitis B virus and hepatitis C virus in pregnant Sudanese women

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Karsany Mubarak S

2007-10-01

Full Text Available Abstract Background The epidemiology of viral hepatitis during pregnancy is essential for health planners and programme managers. While much data exist concerning viral hepatitis during pregnancy in many African countries, no proper published data are available in Sudan. Aim The study aimed to investigate the sero-prevalance and the possible risk factors for hepatitis B virus (HBV and hepatitis C virus (HCV among antenatal care attendants in central Sudan. Methods During 3 months from March–June 2006, sera were collected from pregnant women at Umdurman Maternity Hospital in Sudan, and they were tested for markers of hepatitis B virus (HBVsAg and HCV. Results HBVsAg was detected in 41 (5.6% out 728 women, Anti-HCV was detected in 3 (0.6% out of 423 women, all of them were not aware of their condition. Age, parity, gestational age, residence, history of blood transfusion, dental manipulations, tattooing and circumcision did not contribute significantly to increased HBVsAg sero-positivity. Conclusion Thus 5.6% of pregnant women were positive for HBVsAg irrespective of their age, parity and socio-demographic characteristics. There was low prevalence of Anti-HCV.

Pathology of fatal lineage 1 and 2 West Nile virus infections in horses in South Africa

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June H. Williams

2014-09-01

Full Text Available Since 2007, West Nile virus (WNV has been reported in South African horses, causing severe neurological signs. All cases were of lineage 2, except for one case that clustered with lineage 1 viruses. In the present study, gross and microscopic lesions of six South African lineage 2-infected horses and the one lineage 1 case are described. Diagnoses were confirmed by real-time reverse-transcriptase polymerase chain reaction (RT-PCR of central nervous system (CNS tissue and one by RT-PCR of a brain virus isolate. The CNS of all cases was negative by RT-PCR or immunohistochemistry (IHC for African horse sickness (AHS, equine encephalosis virus, equine herpes viruses 1 and 4, other zoonotic flaviviruses, alphaviruses, and shunivirus, and either by immunofluorescence or IHC for rabies. Gross visceral lesions were nonspecific but often mimicked those of AHS. The CNS histopathology of WNV lineage 2 cases resembled the nonsuppurative polioencephalomyelitis reported in the Northern Hemisphere lineage 1 and recent Hungarian lineage 2 cases. Occasional meningitis, focal spinal ventral horn poliomalacia, dorsal and lateral horn poliomyelitis, leucomyelitis, asymmetrical ventral motor spinal neuritis and frequent olfactory region involvement were also seen. Lineage 2 cases displayed marked variations in CNS lesion severity, type and distribution, and suggested various viral entry routes into the CNS, based on findings in experimental mice and hamsters. Lineage 1 lesions were comparable to the milder lineage 2 cases. West Nile virus IHC on CNS sections with marked lesions from all cases elicited only two antigen-positive cells in the olfactory cortex of one case. The presence in the CNS of T-lymphocytes, B-lymphocytes, plasma cells and macrophage-monocytes was confirmed by cluster of differentiation (CD 3, CD20, multiple myeloma oncogene 1 (MUM1 and macrophage (MAC 387 IHC.

Virus evolution in the face of the host response

International Nuclear Information System (INIS)

Domingo, E.

2005-01-01

Microbial infections are highly dynamic. Viruses have evolved two main strategies against the host response: interaction or evasion. Interaction is typical of complex DNA viruses. Their genomes encode a number of proteins that exert modulatory functions that alter the immune response of the host. Evasion strategy is used mainly by RNA viruses, and is based on high mutation rates and quasispecies dynamics. The complexity of viral populations demands research on new antiviral strategies that take into consideration the adaptive potential of viruses, in particular RNA viruses. (author)

Viral metagenomics demonstrates that domestic pigs are a potential reservoir for Ndumu virus

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Masembe Charles

2012-09-01

Full Text Available Abstract Background The rising demand for pork has resulted in a massive expansion of pig production in Uganda. This has resulted in increased contact between humans and pigs. Pigs can act as reservoirs for emerging infectious diseases. Therefore identification of potential zoonotic pathogens is important for public health surveillance. In this study, during a routine general surveillance for African swine fever, domestic pigs from Uganda were screened for the presence of RNA and DNA viruses using a high-throughput pyrosequencing method. Findings Serum samples from 16 domestic pigs were collected from five regions in Uganda and pooled accordingly. Genomic DNA and RNA were extracted and sequenced on the 454 GS-FLX platform. Among the sequences assigned to a taxon, 53% mapped to the domestic pig (Sus scrofa. African swine fever virus, Torque teno viruses (TTVs, and porcine endogenous retroviruses were identified. Interestingly, two pools (B and C of RNA origin had sequences that showed 98% sequence identity to Ndumu virus (NDUV. None of the reads had identity to the class Insecta indicating that these sequences were unlikely to result from contamination with mosquito nucleic acids. Conclusions This is the first report of the domestic pig as a vertebrate host for Ndumu virus. NDUV had been previously isolated only from culicine mosquitoes. NDUV therefore represents a potential zoonotic pathogen, particularly given the increasing risk of human-livestock-mosquito contact.

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

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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.

Adaptive properties of Adansonia digitata L. (Baobab) & Parkia biglobosa (Jacq.) R.Br. (African Locust Bean) to drought stress

DEFF Research Database (Denmark)

Bouda, Zoewinde Henri-Noel

been suggested as a strategy to improve local population livelihoods. The present thesis studies the adaptive properties to drought stress of A. digitata and P. biglobosa at nursery level, two species native to African savannas. Nursery trials were established with seeds of seven provenances of each...... of the two species. Three water regimes were applied, corresponding to 100%, 75% and 50% of field capacity. The effects of drought stress on the seedling survival, growth and dry matter partitioning was investigated on both species, and for A. digitata the experiment also included seedling morphology...... and physiology. A. digitata had a much higher survival rate than P. biglobosa. However, both species showed a strong reduction of the relative growth rate (diameter and height) and the total dry weight under the effect of applied water stress. Despite differences between provenances of P. biglobosa...

Olive baboons: a non-human primate model for testing dengue virus type 2 replication.

Science.gov (United States)

Valdés, Iris; Gil, Lázaro; Castro, Jorge; Odoyo, Damián; Hitler, Rikoi; Munene, Elephas; Romero, Yaremis; Ochola, Lucy; Cosme, Karelia; Kariuki, Thomas; Guillén, Gerardo; Hermida, Lisset

2013-12-01

This study evaluated the use of a non-human primate, the olive baboon (Papio anubis), as a model of dengue infection. Olive baboons closely resemble humans genetically and physiologically and have been used extensively for assessing novel vaccine formulations. Two doses of dengue virus type 2 (DENV-2) were tested in baboons: 10(3) and 10(4) pfu. Similarly, African green monkeys received the same quantity of virus and acted as positive controls. Following exposure, high levels of viremia were detected in both animal species. There was a trend to detect more days of viremia and more homogeneous viral titers in animals receiving the low viral dose. In addition, baboons infected with the virus generally exhibited positive virus isolation 1 day later than African green monkeys. Humoral responses consisting of antiviral and neutralizing antibodies were detected in all animals after infection. We conclude that baboons provide an alternative non-human primate species for experimental DENV-2 infection and we recommend their use for further tests of vaccines, administering the lowest dose assayed: 10(3) pfu. Copyright © 2013 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Slow progression of paediatric HIV disease: Selective adaptation or ...

African Journals Online (AJOL)

In the European Caucasian populations, the chemokine-cell receptor variant CCR5 \\"Delta 32\\" is a the genetic determinant of HIV disease progression that is believed to have been selected for in the general population by exposure to antigens closely interlinked to HIV like Yersinia pestis or small pox virus. Among African ...

Founder virus population related to route of virus transmission: a determinant of intrahost human immunodeficiency virus type 1 evolution?

NARCIS (Netherlands)

Lukashov, V. V.; Goudsmit, J.

1997-01-01

We and others have shown that in individual human immunodeficiency virus type 1 (HIV-1) infection, the adaptive evolution of HIV-1 is influenced by host immune competence. In this study, we tested the hypothesis that in addition to selective forces operating within the host, transmission bottlenecks

Wild type measles virus attenuation independent of type I IFN

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Horvat Branka

2008-02-01

Full Text Available Abstract Background Measles virus attenuation has been historically performed by adaptation to cell culture. The current dogma is that attenuated virus strains induce more type I IFN and are more resistant to IFN-induced protection than wild type (wt. Results The adaptation of a measles virus isolate (G954-PBL by 13 passages in Vero cells induced a strong attenuation of this strain in vivo. The adapted virus (G954-V13 differs from its parental strain by only 5 amino acids (4 in P/V/C and 1 in the M gene. While a vaccine strain, Edmonston Zagreb, could replicate equally well in various primate cells, both G954 strains exhibited restriction to the specific cell type used initially for their propagation. Surprisingly, we observed that both G954 strains induced type I IFN, the wt strain inducing even more than the attenuated ones, particularly in human plasmacytoid Dendritic Cells. Type I IFN-induced protection from the infection of both G954 strains depended on the cell type analyzed, being less efficient in the cells used to grow the viral strain. Conclusion Thus, mutations in M and P/V/C proteins can critically affect MV pathogenicity, cellular tropism and lead to virus attenuation without interfering with the α/β IFN system.

Blood transfusion and hepatitis viruses | Bird | South African Medical ...

African Journals Online (AJOL)

Transmission of hepatitis viruses has been recognised as an undesirable effect of blood transfusion since the 1940s, when large outbreaks occurred following inoculation with a yellow fever vaccine which contained pooled human plasma. Further reports followed of jaundice occurring several months after transfusions with ...

Avian influenza A viruses: From zoonosis to pandemic

NARCIS (Netherlands)

M. Richard (Mathilde); M.T. de Graaf (Marieke); S. Herfst (Sander)

2014-01-01

textabstractZoonotic influenza A viruses originating from the animal reservoir pose a threat for humans, as they have the ability to trigger pandemics upon adaptation to and invasion of an immunologically naive population. Of particular concern are the H5N1 viruses that continue to circulate in

The Extended African American Family: A Pragmatic Strategy That Blunts the Blade of Injustice.

Science.gov (United States)

Ford, Donna Yvette; And Others

1991-01-01

Considers the extended African-American family, beginning with a historical perspective of the nuclear family and other family arrangements. The importance of the group rather than the individual for African-American culture is explored. Analyses of the function of the extended family indicate its role in adaptation and survival. (SLD)

Recently Identified Mutations in the Ebola Virus-Makona Genome Do Not Alter Pathogenicity in Animal Models

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Andrea Marzi

2018-05-01

Full Text Available Summary: Ebola virus (EBOV, isolate Makona, the causative agent of the West African EBOV epidemic, has been the subject of numerous investigations to determine the genetic diversity and its potential implication for virus biology, pathogenicity, and transmissibility. Despite various mutations that have emerged over time through multiple human-to-human transmission chains, their biological relevance remains questionable. Recently, mutations in the glycoprotein GP and polymerase L, which emerged and stabilized early during the outbreak, have been associated with improved viral fitness in cell culture. Here, we infected mice and rhesus macaques with EBOV-Makona isolates carrying or lacking those mutations. Surprisingly, all isolates behaved very similarly independent of the genotype, causing severe or lethal disease in mice and macaques, respectively. Likewise, we could not detect any evidence for differences in virus shedding. Thus, no specific biological phenotype could be associated with these EBOV-Makona mutations in two animal models. : Marzi et al. demonstrate that recently identified mutations in the EBOV-Makona genome, which appeared during the West African epidemic, do not significantly alter pathogenicity in IFNAR−/− mice and rhesus macaques. Other factors may have been more important for increased case numbers, case fatalities, and human-to-human transmission during this unprecedented epidemic. Keywords: Ebola virus, Ebola Makona, glycoprotein GP, polymerase L, GP mutation A82V, L mutation D759G, West African epidemic, pathogenicity

Integrated analysis for genotypic adaptation in rice | Das | African ...

African Journals Online (AJOL)

Integrated analysis for genotypic adaptation in rice. S Das, RC Misra, MC Pattnaik, SK Sinha. Abstract. Development of varieties with high yield potential coupled with wide adaptability is an important plant breeding objective. The presence of genotype by environment (GxE) interaction plays a crucial role in determining the ...

Hypervariable region 1 deletion and required adaptive envelope mutations confer decreased dependency on scavenger receptor class B type I and low-density lipoprotein receptor for hepatitis C virus

DEFF Research Database (Denmark)

Prentoe, Jannick; Serre, Stéphanie B N; Ramirez, Santseharay

2014-01-01

-deleted viruses. Apolipoprotein E (ApoE)-specific HCV neutralization was similar for H77, J6, and S52 viruses with and without HVR1. In conclusion, HVR1 and HVR1-related adaptive envelope mutations appeared to be involved in LDLr and SR-BI dependency, respectively. Also, LDLr served Apo....../S733F), S52(ΔHVR1/A369V), and S52(A369V), but not for J6(ΔHVR1). Low-density lipoprotein receptor (LDLr) dependency was decreased for HVR1-deleted viruses, but not for H77(N476D/S733F) and S52(A369V). Soluble LDLr neutralization revealed strong inhibition of parental HCV but limited effect against HVR1...

Factors influencing HIV-risk behaviors among HIV-positive urban African Americans.

Science.gov (United States)

Plowden, Keith O; Fletcher, Audwin; Miller, J Lawrence

2005-01-01

Urban African Americans are disproportionately affected by HIV, the virus associated with AIDS. Although incidence and mortality appear to be decreasing in some populations, they continue to remain steady among inner-city African Americans. A major concern is the number of HIV-positive individuals who continue to practice high-risk behaviors. Understanding factors that increase risks is essential for the development and implementation of effective prevention initiatives. Following a constructionist epistemology, this study used ethnography to explore social and cultural factors that influence high-risk behaviors among inner-city HIV-positive African Americans. Leininger's culture care diversity and universality theory guided the study. Individual qualitative interviews were conducted with HIV-positive African Americans in the community to explore social and cultural factors that increase HIV-risky behaviors. For this study, family/kinship, economic, and education factors played a significant role in risky behaviors. Reducing HIV disparity among African Americans is dependent on designing appropriate interventions that enhance protective factors. Clinicians providing care to HIV-positive individuals can play a key role in reducing transmission by recognizing and incorporating these factors when designing effective prevention interventions.

Evolutionary and Functional Analysis of Old World Primate TRIM5 Reveals the Ancient Emergence of Primate Lentiviruses and Convergent Evolution Targeting a Conserved Capsid Interface.

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Kevin R McCarthy

2015-08-01

Full Text Available The widespread distribution of lentiviruses among African primates, and the lack of severe pathogenesis in many of these natural reservoirs, are taken as evidence for long-term co-evolution between the simian immunodeficiency viruses (SIVs and their primate hosts. Evidence for positive selection acting on antiviral restriction factors is consistent with virus-host interactions spanning millions of years of primate evolution. However, many restriction mechanisms are not virus-specific, and selection cannot be unambiguously attributed to any one type of virus. We hypothesized that the restriction factor TRIM5, because of its unique specificity for retrovirus capsids, should accumulate adaptive changes in a virus-specific fashion, and therefore, that phylogenetic reconstruction of TRIM5 evolution in African primates should reveal selection by lentiviruses closely related to modern SIVs. We analyzed complete TRIM5 coding sequences of 22 Old World primates and identified a tightly-spaced cluster of branch-specific adaptions appearing in the Cercopithecinae lineage after divergence from the Colobinae around 16 million years ago. Functional assays of both extant TRIM5 orthologs and reconstructed ancestral TRIM5 proteins revealed that this cluster of adaptations in TRIM5 specifically resulted in the ability to restrict Cercopithecine lentiviruses, but had no effect (positive or negative on restriction of other retroviruses, including lentiviruses of non-Cercopithecine primates. The correlation between lineage-specific adaptations and ability to restrict viruses endemic to the same hosts supports the hypothesis that lentiviruses closely related to modern SIVs were present in Africa and infecting the ancestors of Cercopithecine primates as far back as 16 million years ago, and provides insight into the evolution of TRIM5 specificity.

Management and care of African dormice (Graphiurus kelleni).

Science.gov (United States)

Kastenmayer, Robin J; Moak, Hannah B; Jeffress, Erin J; Elkins, William R

2010-03-01

African dormice (Graphiurus spp.) are small nocturnal rodents that currently are uncommon in laboratory settings. Their use may increase as they have recently been shown to develop an infection with monkeypox virus and may prove to be a valuable animal model for infectious disease research. Because African dormice are not commercially available, an extensive breeding colony is required to produce the animals needed for research use. Husbandry modifications that increased the production of offspring were the use of a high-protein diet, increased cage enrichment, and decreased animal density. To optimize consumption of a high-protein diet, we tested the palatability of several high-protein foods in a series of preference trials. Dormice preferred wax worm larva, cottage cheese, roasted soy nuts, and canned chicken. Issues related to medical management of Graphiurus kelleni include potential complications from traumatic injury. The development of a program for the husbandry and care of African dormice at our institution typifies the experiences of many laboratory animal facilities that are asked to support the development of animal models using novel species.

Impact of using different blood donor subpopulations and models on the estimation of transfusion transmission residual risk of human immunodeficiency virus, hepatitis B virus, and hepatitis C virus in Zimbabwe.

Science.gov (United States)

Mapako, Tonderai; Janssen, Mart P; Mvere, David A; Emmanuel, Jean C; Rusakaniko, Simbarashe; Postma, Maarten J; van Hulst, Marinus

2016-06-01

Various models for estimating the residual risk (RR) of transmission of infections by blood transfusion have been published mainly based on data from high-income countries. However, to obtain the data required for such an assessment remains challenging for most developing settings. The National Blood Service Zimbabwe (NBSZ) adapted a published incidence-window period (IWP) model, which has less demanding data requirements. In this study we assess the impact of various definitions of blood donor subpopulations and models on RR estimates. We compared the outcomes of two published models and an adapted NBSZ model. The Schreiber IWP model (Model 1), an amended version (Model 2), and an adapted NBSZ model (Model 3) were applied. Variably the three models include prevalence, incidence, preseroconversion intervals, mean lifetime risk, and person-years at risk. Annual mean RR estimates and 95% confidence intervals for each of the three models for human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) were determined using NBSZ blood donor data from 2002 through 2011. The annual mean RR estimates for Models 1 through 3 were 1 in 6542, 5805, and 6418, respectively for HIV; 1 in 1978, 2027, and 1628 for HBV; and 1 in 9588, 15,126, and 7750, for HCV. The adapted NBSZ model provided comparable results to the published methods and these highlight the high occurrence of HBV in Zimbabwe. The adapted NBSZ model could be used as an alternative to estimate RRs when in settings where two repeat donations are not available. © 2016 AABB.

A lion lentivirus related to feline immunodeficiency virus: epidemiologic and phylogenetic aspects.

Science.gov (United States)

Brown, E W; Yuhki, N; Packer, C; O'Brien, S J

1994-09-01

Feline immunodeficiency virus (FIV) is a novel lentivirus that is genetically homologous and functionally analogous to the human AIDS viruses, human immunodeficiency virus types 1 and 2. FIV causes immunosuppression in domestic cats by destroying the CD4 T-lymphocyte subsets in infected hosts. A serological survey of over 400 free-ranging African and Asian lions (Panthera leo) for antibodies to FIV revealed endemic lentivirus prevalence with an incidence of seropositivity as high as 90%. A lion lentivirus (FIV-Ple) was isolated by infection of lion lymphocytes in vitro. Seroconversion was documented in two Serengeti lions, and discordance of mother-cub serological status argues against maternal transmission (in favor of horizontal spread) as a major route of infection among lions. A phylogenetic analysis of cloned FIV-Ple pol gene sequences from 27 lions from four African populations (from the Serengeti reserve, Ngorongoro Crater, Lake Manyara, and Kruger Park) revealed remarkably high intra- and interindividual genetic diversity at the sequence level. Three FIV-Ple phylogenetic clusters or clades were resolved with phenetic, parsimony, and likelihood analytical procedures. The three clades, which occurred not only together in the same population but throughout Africa, were as divergent from each other as were homologous pol sequences of lentivirus isolated from distinct feline species, i.e., puma and domestic cat. The FIV-Ple clades, however, were more closely related to each other than to other feline lentiviruses (monophyletic for lion species), suggesting that the ancestors of FIV-Ple evolved in allopatric (geographically isolated) lion populations that converged recently. To date, there is no clear evidence of FIV-Ple-associated pathology, raising the possibility of a historic genetic accommodation of the lion lentivirus and its host leading to a coevolved host-parasite symbiosis (or commensalism) in the population similar to that hypothesized for endemic

Polymerase chain reaction to search for Herpes viruses in uveitic ...

African Journals Online (AJOL)

Objective: To analyse aqueous polymerase chain reaction (PCR) results in patients diagnosed with undifferentiated uveitis ... Cite as: Laaks D, Smit DP, Harvey J. Polymerase chain reaction to search for Herpes viruses in uveitic and healthy eyes: a South African ... may be mild and patients do not seek medical attention.

Chimeric human parainfluenza virus bearing the Ebola virus glycoprotein as the sole surface protein is immunogenic and highly protective against Ebola virus challenge

International Nuclear Information System (INIS)

Bukreyev, Alexander; Marzi, Andrea; Feldmann, Friederike; Zhang Liqun; Yang Lijuan; Ward, Jerrold M.; Dorward, David W.; Pickles, Raymond J.; Murphy, Brian R.; Feldmann, Heinz; Collins, Peter L.

2009-01-01

We generated a new live-attenuated vaccine against Ebola virus (EBOV) based on a chimeric virus HPIV3/ΔF-HN/EboGP that contains the EBOV glycoprotein (GP) as the sole transmembrane envelope protein combined with the internal proteins of human parainfluenza virus type 3 (HPIV3). Electron microscopy analysis of the virus particles showed that they have an envelope and surface spikes resembling those of EBOV and a particle size and shape resembling those of HPIV3. When HPIV3/ΔF-HN/EboGP was inoculated via apical surface of an in vitro model of human ciliated airway epithelium, the virus was released from the apical surface; when applied to basolateral surface, the virus infected basolateral cells but did not spread through the tissue. Following intranasal (IN) inoculation of guinea pigs, scattered infected cells were detected in the lungs by immunohistochemistry, but infectious HPIV3/ΔF-HN/EboGP could not be recovered from the lungs, blood, or other tissues. Despite the attenuation, the virus was highly immunogenic, and a single IN dose completely protected the animals against a highly lethal intraperitoneal challenge of guinea pig-adapted EBOV

Effects of two amino acid substitutions in the capsid proteins on the interaction of two cell-adapted PanAsia-1 strains of foot-and-mouth disease virus serotype O with heparan sulfate receptor.

Science.gov (United States)

Bai, Xingwen; Bao, Huifang; Li, Pinghua; Wei, Wei; Zhang, Meng; Sun, Pu; Cao, Yimei; Lu, Zengjun; Fu, Yuanfang; Xie, Baoxia; Chen, Yingli; Li, Dong; Luo, Jianxun; Liu, Zaixin

2014-07-24

Some cell-adapted strains of foot-and-mouth disease virus (FMDV) can utilize heparan sulfate (HS) as a receptor to facilitate viral infection in cultured cells. A number of independent sites on the capsid that might be involved in FMDV-HS interaction have been studied. However, the previously reported residues do not adequately explain HS-dependent infection of two cell-adapted PanAsia-1 strains (O/Tibet/CHA/6/99tc and O/Fujian/CHA/9/99tc) of FMDV serotype O. To identify the molecular determinant(s) for the interaction of O/Tibet/CHA/6/99tc and O/Fujian/CHA/9/99tc with HS receptor, several chimeric viruses and site-directed mutants were generated by using an infectious cDNA of a non-HS-utilizing rescued virus (Cathay topotype) as the genomic backbone. Phenotypic properties of these viruses were determined by plaque assays and virus adsorption and penetration assays in cultured cells. Only two of the rescued viruses encoding VP0 of O/Tibet/CHA/6/99tc or VP1 of O/Fujian/CHA/9/99tc formed plaques on wild-type Chinese hamster ovary (WT-CHO; HS+) cells, but not on HS-negative pgsD-677 cells. The formation of plaques by these two chimeric viruses on WT-CHO cells could be abolished by the introduction of single amino acid mutations Gln-2080 → Leu in VP2 of O/Tibet/CHA/6/99tc and Lys-1083 → Glu in VP1 of O/Fujian/CHA/9/99tc, respectively. Nonetheless, the introduced mutation Leu-2080 → Gln in VP2 of O/Fujian/CHA/9/99tc for the construction of expectant recombinant plasmid led to non-infectious progeny virus in baby hamster kidney 21 (BHK-21) cells, and the site-directed mutant encoding Glu-1083 → Lys in VP1 of O/Tibet/CHA/6/99tc did not acquire the ability to produce plaques on WT-CHO cells. Significant differences in the inhibition of the infectivity of four HS-utilizing viruses by heparin and RGD-containing peptide were observed in BHK-21 cells. Interestingly, the chimeric virus encoding VP0 of O/Fujian/CHA/9/99tc, and the site-directed mutant

What girls won't do for love: human immunodeficiency virus/sexually transmitted infections risk among young African-American women driven by a relationship imperative.

Science.gov (United States)

Raiford, Jerris L; Seth, Puja; DiClemente, Ralph J

2013-05-01

Rates of Human immunodeficiency virus (HIV) and other sexually transmitted infections (STIs) continue to increase among African-American youth. Adolescents who have a stronger identity in relation to others (relational identity) rather than to themselves (self-identity) may view intimate relationships as imperative to a positive self-concept, which may lead to risky sexual behavior and abuse. Therefore, the present study assessed the associations among a relationship imperative and HIV/STI-related risk factors and behaviors. Participants were 715 African-American adolescent females, aged 15 to 21 years. They completed measures that assessed how important a relationship was to them and HIV-related risk factors and behaviors. Participants also provided vaginal swab specimens for STI testing. Multivariate logistic regression analyses, controlling for covariates, were conducted. Females who endorsed a relationship imperative (29%), compared to those who did not, were more likely to report: unprotected sex, less power in their relationships, perceived inability to refuse sex, anal sex, sex while their partner was high on alcohol/drugs, and partner abuse. Furthermore, participants with less power, recent partner abuse, and a perceived ability to refuse sex were more likely to test STI positive. These results indicate that if African-American adolescent females believe a relationship is imperative, they are more likely to engage in riskier sexual behaviors. Additionally, less perceived power and partner abuse increases their risk for STIs. HIV/STI prevention programs should target males and females and address healthy relationships, sense of self-worth, self-esteem and the gender power imbalance that may persist in the community along with HIV/STI risk. Published by Elsevier Inc.

Molecular cloning of a Bangladeshi strain of very virulent infectious bursal disease virus of chickens and its adaptation in tissue culture by site-directed mutagenesis

International Nuclear Information System (INIS)

Islam, M.R.; Raue, R.; Mueller, H.

2005-01-01

Full-length cDNA of both genome segments of a Bangladeshi strain of very virulent infectious bursal disease virus (BD 3/99) were cloned in plasmid vectors along with the T7 promoter tagged to the 5'-ends. Mutations were introduced in the cloned cDNA to bring about two amino acid exchanges (Q253H and A284T) in the capsid protein VP2. Transfection of primary chicken embryo fibroblast cells with RNA transcribed in vitro from the full-length cDNA resulted in the formation of mutant infectious virus particles that grow in tissue culture. The pathogenicity of this molecularly-cloned, tissue-culture- adapted virus (BD-3tc) was tested in commercial chickens. The parental wild-type strain, BD 3/99, was included for comparison. The subclinical course of the disease and delayed bursal atrophy in BD-3tc-inoculated birds suggested that these amino acid substitutions made BD-3tc partially attenuated. (author)

Formation of high-order oligomers is required for functional bioactivity of an African bat henipavirus surface glycoprotein.

Science.gov (United States)

Behner, Laura; Zimmermann, Louisa; Ringel, Marc; Weis, Michael; Maisner, Andrea

2018-05-01

Hendra virus (HeV) and Nipah virus (NiV) are highly pathogenic henipaviruses originating from fruit bats in Australia and Asia that can cause severe infections in livestock and humans. In recent years, also African bat henipaviruses were identified at the nucleic acid level. To assess their potential to replicate in non-bat species, several studies were performed to characterize the two surface glycoproteins required for virus entry and spread by cell-cell fusion. It has been shown that surface expression and fusion-helper function of the receptor-binding G protein of Kumasi virus (KV), the prototypic Ghanaian bat henipavirus, is reduced compared to other non-African henipavirus G proteins. Immunostainings and pulse-chase analysis revealed a delayed export of KV G from the ER. As defects in oligomerization of viral glycoproteins can be responsible for limited surface transport thereby restricting the bioactivity, we analyzed the oligomerization pattern of KV G. In contrast to HeV and NiV whose G proteins are known to be expressed at a dimer-tetramer ratio of 1:1, KV G almost exclusively formed stable tetramers or higher oligomers. KV G also showed less stringent requirements for defined stalk cysteines to form dimers and tetramers. Interestingly, any changes in the oligomeric forms negatively affected the fusion-helper activity although surface expression and receptor binding was unchanged. This clearly indicates that the formation of mostly higher oligomeric KV G forms is not a deficiency responsible for ER retention, but is rather a basic structural feature essential for the bioactivity of this African bat henipavirus glycoprotein. Copyright © 2018 Elsevier B.V. All rights reserved.

Knuckle-walking anteater: a convergence test of adaptation for purported knuckle-walking features of African Hominidae.

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Orr, Caley M

2005-11-01

Appeals to synapomorphic features of the wrist and hand in African apes, early hominins, and modern humans as evidence of knuckle-walking ancestry for the hominin lineage rely on accurate interpretations of those features as adaptations to knuckle-walking locomotion. Because Gorilla, Pan, and Homo share a relatively close common ancestor, the interpretation of such features is confounded somewhat by phylogeny. The study presented here examines the evolution of a similar locomotor regime in New World anteaters (order Xenarthra, family Myrmecophagidae) and uses the terrestrial giant anteater (Myrmecophaga tridactyla) as a convergence test of adaptation for purported knuckle-walking features of the Hominidae. During the stance phase of locomotion, Myrmecophaga transmits loads through flexed digits and a vertical manus, with hyperextension occurring at the metacarpophalangeal joints of the weight-bearing rays. This differs from the locomotion of smaller, arboreal anteaters of outgroup genera Tamandua and Cyclopes that employ extended wrist postures during above-branch quadrupedality. A number of features shared by Myrmecophaga and Pan and Gorilla facilitate load transmission or limit extension, thereby stabilizing the wrist and hand during knuckle-walking, and distinguish these taxa from their respective outgroups. These traits are a distally extended dorsal ridge of the distal radius, proximal expansion of the nonarticular surface of the dorsal capitate, a pronounced articular ridge on the dorsal aspects of the load-bearing metacarpal heads, and metacarpal heads that are wider dorsally than volarly. Only the proximal expansion of the nonarticular area of the dorsal capitate distinguishes knuckle-walkers from digitigrade cercopithecids, but features shared with digitigrade primates might be adaptive to the use of a vertical manus of some sort in the stance phase of terrestrial locomotion. The appearance of capitate nonarticular expansion and the dorsal ridge of the

Comparative phylogeography of African fruit bats (Chiroptera, Pteropodidae) provide new insights into the outbreak of Ebola virus disease in West Africa, 2014-2016.

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Hassanin, Alexandre; Nesi, Nicolas; Marin, Julie; Kadjo, Blaise; Pourrut, Xavier; Leroy, Éric; Gembu, Guy-Crispin; Musaba Akawa, Prescott; Ngoagouni, Carine; Nakouné, Emmanuel; Ruedi, Manuel; Tshikung, Didier; Pongombo Shongo, Célestin; Bonillo, Céline

Both Ebolavirus and Marburgvirus were detected in several fruit bat species of the family Pteropodidae, suggesting that this taxon plays a key role in the life cycle of filoviruses. After four decades of Zaire Ebolavirus (ZEBOV) outbreaks in Central Africa, the virus was detected for the first time in West Africa in 2014. To better understand the role of fruit bats as potential reservoirs and circulating hosts between Central and West Africa, we examine here the phylogeny and comparative phylogeography of Pteropodidae. Our phylogenetic results confirm the existence of four independent lineages of African fruit bats: the genera Eidolon and Rousettus, and the tribes Epomophorini and Scotonycterini, and indicate that the three species suspected to represent ZEBOV reservoir hosts (Epomops franqueti, Hypsignathus monstrosus, and Myonycteris torquata) belong to an African clade that diversified rapidly around 8-7 Mya. To test for phylogeographic structure and for recent gene flow from Central to West Africa, we analysed the nucleotide variation of 675 cytochrome b gene (Cytb) sequences, representing eight fruit bat species collected in 48 geographic localities. Within Epomophorina, our mitochondrial data do not support the monophyly of two genera (Epomops and Epomophorus) and four species (Epomophorus gambianus, Epomops franqueti, Epomops buettikoferi, and Micropteropus pusillus). In Epomops, however, we found two geographic haplogroups corresponding to the Congo Basin and Upper Guinea forests, respectively. By contrast, we found no genetic differentiation between Central and West African populations for all species known to make seasonal movements, Eidolon helvum, E. gambianus, H. monstrosus, M. pusillus, Nanonycteris veldkampii, and Rousettus aegyptiacus. Our results suggest that only three fruit bat species were able to disperse directly ZEBOV from the Congo Basin to Upper Guinea: E. helvum, H. monstrosus, and R. aegyptiacus. Copyright © 2016 Académie des

Cell culture-adaptive mutations of NS5A affect replication of hepatitis C virus differentially depending on the viral genotypes.

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Chung, Aeri; Jin, Bora; Han, Kwang-Hyub; Ahn, Sang Hoon; Kim, Seungtaek

2017-01-01

Most of HCV RNAs require cell culture-adaptive mutations for efficient replication in cell culture and a number of such mutations have been described including a well-known S2204I substitution mutation in NS5A protein. In contrast, the replication of genotype 2a JFH1 RNA in cell culture does not require any cell culture-adaptive mutation. Rather, the presence of S2204I mutation impaired the JFH1 RNA replication. In this study, we examined the effect of reversions and substitutions of NS5A cell culture-adaptive mutations on virus replication in different genotypic backgrounds after either placing genotype 1a NS5A in the genotype 2a JFH1 or vice versa. The results from this investigation suggest that the S2204I mutation affects HCV RNA replication differentially depending on the viral genotypes but that the effect was not simply explained by the genotypic background. Perhaps, the effect of the S2204I mutation on HCV replication reflects both intra- and intergenic interactions of NS5A protein. J. Med. Virol. 89:146-152, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Recent advances on Ebola virus

OpenAIRE

Yasir Waheed; Mehreen Tahir; Hasnain Waheed; Sher Zaman Safi

2017-01-01

The 2014–2015 Ebola epidemic in West Africa was the largest of its kind, with more than 11 000 deaths and 28 637 cases. The epidemic mobilized a coalition of countries from US to China, European Union, and African countries. The international community was not prepared to face this unprecedented epidemic. Numbers of research groups are working to find a potent vaccine against Ebola. Ebola virus has the ability to dodge the immune system either by blocking interferon production ...

Molecular characterization and prevalence of two capulaviruses: Alfalfa leaf curl virus from France and Euphorbia caput-medusae latent virus from South Africa.

Science.gov (United States)

Bernardo, Pauline; Muhire, Brejnev; François, Sarah; Deshoux, Maëlle; Hartnady, Penelope; Farkas, Kata; Kraberger, Simona; Filloux, Denis; Fernandez, Emmanuel; Galzi, Serge; Ferdinand, Romain; Granier, Martine; Marais, Armelle; Monge Blasco, Pablo; Candresse, Thierry; Escriu, Fernando; Varsani, Arvind; Harkins, Gordon W; Martin, Darren P; Roumagnac, Philippe

2016-06-01

Little is known about the prevalence, diversity, evolutionary processes, genomic structures and population dynamics of viruses in the divergent geminivirus lineage known as the capulaviruses. We determined and analyzed full genome sequences of 13 Euphorbia caput-medusae latent virus (EcmLV) and 26 Alfalfa leaf curl virus (ALCV) isolates, and partial genome sequences of 23 EcmLV and 37 ALCV isolates. While EcmLV was asymptomatic in uncultivated southern African Euphorbia caput-medusae, severe alfalfa disease symptoms were associated with ALCV in southern France. The prevalence of both viruses exceeded 10% in their respective hosts. Besides using patterns of detectable negative selection to identify ORFs that are probably functionally expressed, we show that ALCV and EcmLV both display evidence of inter-species recombination and biologically functional genomic secondary structures. Finally, we show that whereas the EcmLV populations likely experience restricted geographical dispersion, ALCV is probably freely moving across the French Mediterranean region. Copyright © 2016 Elsevier Inc. All rights reserved.

Differential impact of respiratory syncytial virus and parainfluenza virus on the frequency of acute otitis media is explained by lower adaptive and innate immune responses in otitis-prone children.

Science.gov (United States)

Verhoeven, David; Xu, Qingfu; Pichichero, Michael E

2014-08-01

Acute otitis media (AOM) is a leading cause of bacterial pediatric infections associated with viral upper respiratory infections (URIs). We examined the differential impact of respiratory syncytial virus (RSV) and parainfluenza virus URIs on the frequency of AOM caused by Streptococcus pneumoniae (Spn) and nontypeable Haemophilus influenzae (NTHi) in stringently defined otitis-prone (sOP) and non-otitis-prone (NOP) children as a potential mechanism to explain increased susceptibility to AOM. Peripheral blood and nasal washes were obtained from sOP and NOP children (n = 309). Colonization events and antiviral responses consisting of total specific immunoglobulin G (IgG) responses, neutralizing antibody responses, and T-cell responses were determined. Isolated neutrophils were infected with varying multiplicities of infection of both viruses, and opsonophagocytosis potential was measured. A significant increase was found in frequency of AOM events caused by Spn and NTHi, with a concurrent RSV infection in sOP children. These results correlated with diminished total RSV-specific IgG, higher viral nasal burdens, and lower IgG neutralizing capacity. The sOP children had diminished T-cell responses to RSV that correlated with lower Toll-like receptor 3/7 transcript and decreased expression of HLA-DR on antigen-presenting cells. RSV interfered with the Spn phagocytic capacity of neutrophils in a dose-dependent manner. Parainfluenza virus infections did not differentially affect AOM events in sOP and NOP children. Lower innate and adaptive immune responses to RSV in sOP children may slow the kinetics of viral clearance from the nasopharynx and allow for viral interference with antibacterial immune responses, thus contributing to increased frequency of AOMs. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Selective interaction of heparin with the variable region 3 within surface glycoprotein of laboratory-adapted feline immunodeficiency virus.

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Qiong-Ying Hu

Full Text Available Heparan sulfate proteoglycans (HSPG can act as binding receptors for certain laboratory-adapted (TCA strains of feline immunodeficiency virus (FIV and human immunodeficiency virus (HIV. Heparin, a soluble heparin sulfate (HS, can inhibit TCA HIV and FIV entry mediated by HSPG interaction in vitro. In the present study, we further determined the selective interaction of heparin with the V3 loop of TCA of FIV. Our current results indicate that heparin selectively inhibits infection by TCA strains, but not for field isolates (FS. Heparin also specifically interferes with TCA surface glycoprotein (SU binding to CXCR4, by interactions with HSPG binding sites on the V3 loop of the FIV envelope protein. Peptides representing either the N- or C-terminal side of the V3 loop and containing HSPG binding sites were able to compete away the heparin block of TCA SU binding to CXCR4. Heparin does not interfere with the interaction of SU with anti-V3 antibodies that target the CXCR4 binding region or with the interaction between FS FIV and anti-V3 antibodies since FS SU has no HSPG binding sites within the HSPG binding region. Our data show that heparin blocks TCA FIV infection or entry not only through its competition of HSPG on the cell surface interaction with SU, but also by its interference with CXCR4 binding to SU. These studies aid in the design and development of heparin derivatives or analogues that can inhibit steps in virus infection and are informative regarding the HSPG/SU interaction.

Avian Influenza virus glycoproteins restrict virus replication and spread through human airway epithelium at temperatures of the proximal airways.

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Margaret A Scull

2009-05-01

Full Text Available Transmission of avian influenza viruses from bird to human is a rare event even though avian influenza viruses infect the ciliated epithelium of human airways in vitro and ex vivo. Using an in vitro model of human ciliated airway epithelium (HAE, we demonstrate that while human and avian influenza viruses efficiently infect at temperatures of the human distal airways (37 degrees C, avian, but not human, influenza viruses are restricted for infection at the cooler temperatures of the human proximal airways (32 degrees C. These data support the hypothesis that avian influenza viruses, ordinarily adapted to the temperature of the avian enteric tract (40 degrees C, rarely infect humans, in part due to differences in host airway regional temperatures. Previously, a critical residue at position 627 in the avian influenza virus polymerase subunit, PB2, was identified as conferring temperature-dependency in mammalian cells. Here, we use reverse genetics to show that avianization of residue 627 attenuates a human virus, but does not account for the different infection between 32 degrees C and 37 degrees C. To determine the mechanism of temperature restriction of avian influenza viruses in HAE at 32 degrees C, we generated recombinant human influenza viruses in either the A/Victoria/3/75 (H3N2 or A/PR/8/34 (H1N1 genetic background that contained avian or avian-like glycoproteins. Two of these viruses, A/Victoria/3/75 with L226Q and S228G mutations in hemagglutinin (HA and neuraminidase (NA from A/Chick/Italy/1347/99 and A/PR/8/34 containing the H7 and N1 from A/Chick/Italy/1347/99, exhibited temperature restriction approaching that of wholly avian influenza viruses. These data suggest that influenza viruses bearing avian or avian-like surface glycoproteins have a reduced capacity to establish productive infection at the temperature of the human proximal airways. This temperature restriction may limit zoonotic transmission of avian influenza viruses and

New social adaptability index predicts overall mortality.

Science.gov (United States)

Goldfarb-Rumyantzev, Alexander; Barenbaum, Anna; Rodrigue, James; Rout, Preeti; Isaacs, Ross; Mukamal, Kenneth

2011-08-01

Definitions of underprivileged status based on race, gender and geographic location are neither sensitive nor specific; instead we proposed and validated a composite index of social adaptability (SAI). Index of social adaptability was calculated based on employment, education, income, marital status, and substance abuse, each factor contributing from 0 to 3 points. Index of social adaptability was validated in NHANES-3 by association with all-cause and cause-specific mortality. Weighted analysis of 19,593 subjects demonstrated mean SAI of 8.29 (95% CI 8.17-8.40). Index of social adaptability was higher in Whites, followed by Mexican-Americans and then the African-American population (ANOVA, p adaptability with a strong association with mortality, which can be used to identify underprivileged populations at risk of death.

Fluorescent dye labeled influenza virus mainly infects innate immune cells and activated lymphocytes and can be used in cell-mediated immune response assay

OpenAIRE

Xie, Dongxu

2009-01-01

Early results have recognized that influenza virus infects the innate and adaptive immune cells. The data presented in this paper demonstrated that influenza virus labeled with fluorescent dye not only retained the ability to infect and replicate in host cells, but also stimulated a similar human immune response as did unlabeled virus. Influenza virus largely infected the innate and activated adaptive immune cells. Influenza B type virus was different from that of A type virus. B type virus w...

Density threshold for Mopeia virus invasion and persistence in its host Mastomys natalensis

DEFF Research Database (Denmark)

Goyens, J.; Reijniers, J.; Borremans, B.

2013-01-01

. We developed a spatially explicit and individual-based SEIR model of Mopeia virus in multimammate mice Mastomys natalensis. This is an interesting model system for studying abundance thresholds because the host is the most common African rodent, populations fluctuate considerably and the virus...... is closely related to Lassa virus but non-pathogenic to humans so can be studied safely in the field. The simulations show that, while host density clearly is important, sharp thresholds are only to be expected for persistence (and not for invasion), since at short time-spans (as during invasion...

Comparative Pathogenesis of Asian and African-Lineage Zika Virus in Indian Rhesus Macaque’s and Development of a Non-Human Primate Model Suitable for the Evaluation of New Drugs and Vaccines

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Jonathan O. Rayner

2018-05-01

Full Text Available The establishment of a well characterized non-human primate model of Zika virus (ZIKV infection is critical for the development of medical interventions. In this study, challenging Indian rhesus macaques (IRMs with ZIKV strains of the Asian lineage resulted in dose-dependent peak viral loads between days 2 and 5 post infection and a robust immune response which protected the animals from homologous and heterologous re-challenge. In contrast, viremia in IRMs challenged with an African lineage strain was below the assay’s lower limit of quantitation, and the immune response was insufficient to protect from re-challenge. These results corroborate previous observations but are contrary to reports using other African strains, obviating the need for additional studies to elucidate the variables contributing to the disparities. Nonetheless, the utility of an Asian lineage ZIKV IRM model for countermeasure development was verified by vaccinating animals with a formalin inactivated reference vaccine and demonstrating sterilizing immunity against a subsequent subcutaneous challenge.

Comparative Pathogenesis of Asian and African-Lineage Zika Virus in Indian Rhesus Macaque’s and Development of a Non-Human Primate Model Suitable for the Evaluation of New Drugs and Vaccines

Science.gov (United States)

Kalkeri, Raj; Goebel, Scott; Cai, Zhaohui; Green, Brian; Lin, Shuling; Snyder, Beth; Hagelin, Kimberly; Walters, Kevin B.; Koide, Fusataka

2018-01-01

The establishment of a well characterized non-human primate model of Zika virus (ZIKV) infection is critical for the development of medical interventions. In this study, challenging Indian rhesus macaques (IRMs) with ZIKV strains of the Asian lineage resulted in dose-dependent peak viral loads between days 2 and 5 post infection and a robust immune response which protected the animals from homologous and heterologous re-challenge. In contrast, viremia in IRMs challenged with an African lineage strain was below the assay’s lower limit of quantitation, and the immune response was insufficient to protect from re-challenge. These results corroborate previous observations but are contrary to reports using other African strains, obviating the need for additional studies to elucidate the variables contributing to the disparities. Nonetheless, the utility of an Asian lineage ZIKV IRM model for countermeasure development was verified by vaccinating animals with a formalin inactivated reference vaccine and demonstrating sterilizing immunity against a subsequent subcutaneous challenge. PMID:29723973

Cathepsin B & L are not required for ebola virus replication.

Science.gov (United States)

Marzi, Andrea; Reinheckel, Thomas; Feldmann, Heinz

2012-01-01

Ebola virus (EBOV), family Filoviridae, emerged in 1976 on the African continent. Since then it caused several outbreaks of viral hemorrhagic fever in humans with case fatality rates up to 90% and remains a serious Public Health concern and biothreat pathogen. The most pathogenic and best-studied species is Zaire ebolavirus (ZEBOV). EBOV encodes one viral surface glycoprotein (GP), which is essential for replication, a determinant of pathogenicity and an important immunogen. GP mediates viral entry through interaction with cellular surface molecules, which results in the uptake of virus particles via macropinocytosis. Later in this pathway endosomal acidification activates the cysteine proteases Cathepsin B and L (CatB, CatL), which have been shown to cleave ZEBOV-GP leading to subsequent exposure of the putative receptor-binding and fusion domain and productive infection. We studied the effect of CatB and CatL on in vitro and in vivo replication of EBOV. Similar to previous findings, our results show an effect of CatB, but not CatL, on ZEBOV entry into cultured cells. Interestingly, cell entry by other EBOV species (Bundibugyo, Côte d'Ivoire, Reston and Sudan ebolavirus) was independent of CatB or CatL as was EBOV replication in general. To investigate whether CatB and CatL have a role in vivo during infection, we utilized the mouse model for ZEBOV. Wild-type (control), catB(-/-) and catL(-/-) mice were equally susceptible to lethal challenge with mouse-adapted ZEBOV with no difference in virus replication and time to death. In conclusion, our results show that CatB and CatL activity is not required for EBOV replication. Furthermore, EBOV glycoprotein cleavage seems to be mediated by an array of proteases making targeted therapeutic approaches difficult.

Cathepsin B & L are not required for ebola virus replication.

Directory of Open Access Journals (Sweden)

Andrea Marzi

Full Text Available Ebola virus (EBOV, family Filoviridae, emerged in 1976 on the African continent. Since then it caused several outbreaks of viral hemorrhagic fever in humans with case fatality rates up to 90% and remains a serious Public Health concern and biothreat pathogen. The most pathogenic and best-studied species is Zaire ebolavirus (ZEBOV. EBOV encodes one viral surface glycoprotein (GP, which is essential for replication, a determinant of pathogenicity and an important immunogen. GP mediates viral entry through interaction with cellular surface molecules, which results in the uptake of virus particles via macropinocytosis. Later in this pathway endosomal acidification activates the cysteine proteases Cathepsin B and L (CatB, CatL, which have been shown to cleave ZEBOV-GP leading to subsequent exposure of the putative receptor-binding and fusion domain and productive infection. We studied the effect of CatB and CatL on in vitro and in vivo replication of EBOV. Similar to previous findings, our results show an effect of CatB, but not CatL, on ZEBOV entry into cultured cells. Interestingly, cell entry by other EBOV species (Bundibugyo, Côte d'Ivoire, Reston and Sudan ebolavirus was independent of CatB or CatL as was EBOV replication in general. To investigate whether CatB and CatL have a role in vivo during infection, we utilized the mouse model for ZEBOV. Wild-type (control, catB(-/- and catL(-/- mice were equally susceptible to lethal challenge with mouse-adapted ZEBOV with no difference in virus replication and time to death. In conclusion, our results show that CatB and CatL activity is not required for EBOV replication. Furthermore, EBOV glycoprotein cleavage seems to be mediated by an array of proteases making targeted therapeutic approaches difficult.

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....../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...

Contact with domestic dogs increases pathogen exposure in endangered African wild dogs (Lycaon pictus.

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Rosie Woodroffe

Full Text Available BACKGROUND: Infectious diseases have contributed to the decline and local extinction of several wildlife species, including African wild dogs (Lycaon pictus. Mitigating such disease threats is challenging, partly because uncertainty about disease dynamics makes it difficult to identify the best management approaches. Serious impacts on susceptible populations most frequently occur when generalist pathogens are maintained within populations of abundant (often domestic "reservoir" hosts, and spill over into less abundant host species. If this is the case, disease control directed at the reservoir host might be most appropriate. However, pathogen transmission within threatened host populations may also be important, and may not be controllable by managing another host species. METHODOLOGY/PRINCIPAL FINDINGS: We investigated interspecific and intraspecific transmission routes, by comparing African wild dogs' exposure to six canine pathogens with behavioural measures of their opportunities for contact with domestic dogs and with other wild dogs. Domestic dog contact was associated with exposure to canine parvovirus, Ehrlichia canis, Neospora caninum and perhaps rabies virus, but not with exposure to canine distemper virus or canine coronavirus. Contact with other wild dogs appeared not to increase the risk of exposure to any of the pathogens. CONCLUSIONS/SIGNIFICANCE: These findings, combined with other data, suggest that management directed at domestic dogs might help to protect wild dog populations from rabies virus, but not from canine distemper virus. However, further analyses are needed to determine the management approaches--including no intervention--which are most appropriate for each pathogen.

Contact with Domestic Dogs Increases Pathogen Exposure in Endangered African Wild Dogs (Lycaon pictus)

Science.gov (United States)

Woodroffe, Rosie; Prager, Katherine C.; Conrad, Patricia A.; Dubovi, Edward J.; Mazet, Jonna A. K.

2012-01-01

Background Infectious diseases have contributed to the decline and local extinction of several wildlife species, including African wild dogs (Lycaon pictus). Mitigating such disease threats is challenging, partly because uncertainty about disease dynamics makes it difficult to identify the best management approaches. Serious impacts on susceptible populations most frequently occur when generalist pathogens are maintained within populations of abundant (often domestic) “reservoir” hosts, and spill over into less abundant host species. If this is the case, disease control directed at the reservoir host might be most appropriate. However, pathogen transmission within threatened host populations may also be important, and may not be controllable by managing another host species. Methodology/Principal Findings We investigated interspecific and intraspecific transmission routes, by comparing African wild dogs' exposure to six canine pathogens with behavioural measures of their opportunities for contact with domestic dogs and with other wild dogs. Domestic dog contact was associated with exposure to canine parvovirus, Ehrlichia canis, Neospora caninum and perhaps rabies virus, but not with exposure to canine distemper virus or canine coronavirus. Contact with other wild dogs appeared not to increase the risk of exposure to any of the pathogens. Conclusions/Significance These findings, combined with other data, suggest that management directed at domestic dogs might help to protect wild dog populations from rabies virus, but not from canine distemper virus. However, further analyses are needed to determine the management approaches – including no intervention – which are most appropriate for each pathogen. PMID:22238695

Quantitative estimation of Nipah virus replication kinetics in vitro

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Hassan Sharifah

2006-06-01

Full Text Available Abstract Background Nipah virus is a zoonotic virus isolated from an outbreak in Malaysia in 1998. The virus causes infections in humans, pigs, and several other domestic animals. It has also been isolated from fruit bats. The pathogenesis of Nipah virus infection is still not well described. In the present study, Nipah virus replication kinetics were estimated from infection of African green monkey kidney cells (Vero using the one-step SYBR® Green I-based quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR assay. Results The qRT-PCR had a dynamic range of at least seven orders of magnitude and can detect Nipah virus from as low as one PFU/μL. Following initiation of infection, it was estimated that Nipah virus RNA doubles at every ~40 minutes and attained peak intracellular virus RNA level of ~8.4 log PFU/μL at about 32 hours post-infection (PI. Significant extracellular Nipah virus RNA release occurred only after 8 hours PI and the level peaked at ~7.9 log PFU/μL at 64 hours PI. The estimated rate of Nipah virus RNA released into the cell culture medium was ~0.07 log PFU/μL per hour and less than 10% of the released Nipah virus RNA was infectious. Conclusion The SYBR® Green I-based qRT-PCR assay enabled quantitative assessment of Nipah virus RNA synthesis in Vero cells. A low rate of Nipah virus extracellular RNA release and low infectious virus yield together with extensive syncytial formation during the infection support a cell-to-cell spread mechanism for Nipah virus infection.

Neuropsychological long-term sequelae of Ebola virus disease survivors - A systematic review

NARCIS (Netherlands)

Lötsch, Felix; Schnyder, Jenny; Goorhuis, Abraham; Grobusch, Martin P.

2017-01-01

The recent West African Ebola virus disease (EVD) outbreak had catastrophic impact on populations, health care systems and economies of the affected countries. Somatic symptoms have been reported to persist long beyond the acute infection. This review was conducted to provide an overview on neuro-

Is the genetic landscape of the deep subsurface biosphere affected by viruses?

Science.gov (United States)

Anderson, Rika E; Brazelton, William J; Baross, John A

2011-01-01

Viruses are powerful manipulators of microbial diversity, biogeochemistry, and evolution in the marine environment. Viruses can directly influence the genetic capabilities and the fitness of their hosts through the use of fitness factors and through horizontal gene transfer. However, the impact of viruses on microbial ecology and evolution is often overlooked in studies of the deep subsurface biosphere. Subsurface habitats connected to hydrothermal vent systems are characterized by constant fluid flux, dynamic environmental variability, and high microbial diversity. In such conditions, high adaptability would be an evolutionary asset, and the potential for frequent host-virus interactions would be high, increasing the likelihood that cellular hosts could acquire novel functions. Here, we review evidence supporting this hypothesis, including data indicating that microbial communities in subsurface hydrothermal fluids are exposed to a high rate of viral infection, as well as viral metagenomic data suggesting that the vent viral assemblage is particularly enriched in genes that facilitate horizontal gene transfer and host adaptability. Therefore, viruses are likely to play a crucial role in facilitating adaptability to the extreme conditions of these regions of the deep subsurface biosphere. We also discuss how these results might apply to other regions of the deep subsurface, where the nature of virus-host interactions would be altered, but possibly no less important, compared to more energetic hydrothermal systems.

Evaluation of Jatropha curcas as an alternative host of African cassava mosaic virus

International Nuclear Information System (INIS)

Appiah, A.S.

2010-01-01

A study was conducted to evaluate ten local accessions of Jatropha curcas L. (physic nut) as an alternative host of African cassava mosaic virus (ACMV). The ten local accessions of J. curcas were planted in a field trial at the research farm of the Biotechnology and Nuclear Agriculture Research Institute, intercropped with ACMV-infected cassava cultivar 'Afisiafi' and left to natural spread of ACMV from the cassava to J. curcas. The J. curcas plants which became infected generally showed mild symptoms, with severity ranging from 1.00 at eight weeks after planting (WAP) to 3.00 at 16 WAP on a scale of 1 (no symptoms) to 5 (severe symptoms). Whitefly populations recorded on the J. curcas accessions in the wet (Sept. - Oct., 2008) and dry (Jan. - Feb., 2009) seasons were generally low. However, significant differences (p < 0.05) were found in the mean whitefly numbers found on the individual J. curcas accessions in the dry season. Disease incidence as determined by symptom expression varied among accessions at eight, twelve and sixteen weeks after planting, though the differences not statistically significant. Leaf samples from the ten J. curcas accessions were tested at six, nine and twelve months after planting (MAP) for the presence of ACMV by enzyme-linked immunosorbent assays (ELISA) and by polymerase chain reaction (PCR). ELISA tests using monoclonal antibody SCRI 33, in a double antibody sandwich ELISA (DAS-ELISA) showed ACMV infection in the J. curcas accessions. Infection ranged from 0% at 6MAP to 50% at 12MAP. Molecular analysis by PCR with a virus-specific primer (JSP001/JSP002) of the viral DNA extracted from leaves of the number of samples tested, as against 37.7% by ELISA. Infection among the accessions as shown by to PCR varied significantly (p < 0.05) and ranged from as low as 16.6% to as high as 91.6%. ACMV infection of the J. curcas plants was further confirmed by infectivity tests on Nicotiana benthamiana indicator plants. Three of (3) out of 132

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

Science.gov (United States)

2010-10-01

... the monkeypox virus. 71.56 Section 71.56 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND... and other animals that may carry the monkeypox virus. (a) What actions are prohibited? What animals... transmitting or carrying the monkeypox virus. Such products include, but are not limited to, fully taxidermied...

Interpreting South African cultural clashes through Darwinian eyes ...

African Journals Online (AJOL)

... an acceptance of what would soon be known as Afrikaans culture as no less worthy and civilised than that of the British and for the application of a radically adapted version of social Darwinism to conflicts between white and black South Africans. Key words: Balmforth, Darwin, Darwinism, eugenics, evolution, Kant, social

A High Diversity of Eurasian Lineage Low Pathogenicity Avian Influenza A Viruses Circulate among Wild Birds Sampled in Egypt

Science.gov (United States)

Gerloff, Nancy A.; Jones, Joyce; Simpson, Natosha; Balish, Amanda; ElBadry, Maha Adel; Baghat, Verina; Rusev, Ivan; de Mattos, Cecilia C.; de Mattos, Carlos A.; Zonkle, Luay Elsayed Ahmed; Kis, Zoltan; Davis, C. Todd; Yingst, Sam; Cornelius, Claire; Soliman, Atef; Mohareb, Emad; Klimov, Alexander; Donis, Ruben O.

2013-01-01

Surveillance for influenza A viruses in wild birds has increased substantially as part of efforts to control the global movement of highly pathogenic avian influenza A (H5N1) virus. Studies conducted in Egypt from 2003 to 2007 to monitor birds for H5N1 identified multiple subtypes of low pathogenicity avian influenza A viruses isolated primarily from migratory waterfowl collected in the Nile Delta. Phylogenetic analysis of 28 viral genomes was performed to estimate their nearest ancestors and identify possible reassortants. Migratory flyway patterns were included in the analysis to assess gene flow between overlapping flyways. Overall, the viruses were most closely related to Eurasian, African and/or Central Asian lineage low pathogenicity viruses and belonged to 15 different subtypes. A subset of the internal genes seemed to originate from specific flyways (Black Sea-Mediterranean, East African-West Asian). The remaining genes were derived from a mixture of viruses broadly distributed across as many as 4 different flyways suggesting the importance of the Nile Delta for virus dispersal. Molecular clock date estimates suggested that the time to the nearest common ancestor of all viruses analyzed ranged from 5 to 10 years, indicating frequent genetic exchange with viruses sampled elsewhere. The intersection of multiple migratory bird flyways and the resulting diversity of influenza virus gene lineages in the Nile Delta create conditions favoring reassortment, as evident from the gene constellations identified by this study. In conclusion, we present for the first time a comprehensive phylogenetic analysis of full genome sequences from low pathogenic avian influenza viruses circulating in Egypt, underscoring the significance of the region for viral reassortment and the potential emergence of novel avian influenza A viruses, as well as representing a highly diverse influenza A virus gene pool that merits continued monitoring. PMID:23874653

Initial feasibility of a woman-focused intervention for pregnant african-american women.

Science.gov (United States)

Jones, Hendrée E; Berkman, Nancy D; Kline, Tracy L; Ellerson, Rachel Middlesteadt; Browne, Felicia A; Poulton, Winona; Wechsberg, Wendee M

2011-01-01

African-American women who use crack are vulnerable to HIV because of the complex social circumstances in which they live. Drug-abuse treatment for these women during pregnancy may provide time for changing risk behaviors. This paper examines the initial 6-month feasibility of a women-focused HIV intervention, the Women's CoOp, adapted for pregnant women, relative to treatment-as-usual among 59 pregnant African-American women enrolled in drug-abuse treatment. At treatment entry, the women were largely homeless, unemployed, practicing unsafe sex, and involved in violence. Results indicated marked reductions in homelessness, use of cocaine and illegal drugs, involvement in physical violence, and an increase in knowledge of HIV from baseline to 6-month followup for both conditions. Findings suggest that the Women's CoOp intervention could be successfully adapted to treat this hard-to-reach population. Future studies should examine the efficacy of the pregnancy-adapted Women's CoOp for women not enrolled in drug-abuse treatment.

Recombinant cold-adapted attenuated influenza A vaccines for use in children: molecular genetic analysis of the cold-adapted donor and recombinants.

OpenAIRE

Ghendon, Y Z; Polezhaev, F I; Lisovskaya, K V; Medvedeva, T E; Alexandrova, G I; Klimov, A I

1984-01-01

A previously described cold-adapted attenuated virus, A/Leningrad/134/17/57 (H2N2), was further modified by 30 additional passages in chicken embryos at 25 degrees C. This virus had a distinct temperature-sensitive (ts) phenotype, grew well in chicken embryos at 25 degrees C, and failed to recombine with reference ts mutants of fowl plague virus containing ts lesions in five genes coding for non-glycosylated proteins (genes 1, 2, 5, 7, and 8). Recombination of A/Leningrad/134/47/57 with wild-...

Problems in Translating Musical Elements in African American Poetry after 1950

Directory of Open Access Journals (Sweden)

Kristina Kočan

2009-06-01

Full Text Available In most cases, African American poetry eschews traditional literary norms. Contemporary African American poets tend to ignore grammatical rules, use unusual typography on many occasions, include much of their cultural heritage in their poetry, and interweave musical elements into literary genres. The influence of such musical genres as jazz, blues, soul, and gospel, together with the dilemmas that occur for the translator, will be shown to great extent, since music, like black speech, is a major part of African American culture and literature. The translator will have to maintain the specific African American rhythm, blues adaptations and the improvisational language under the jazz impact. The paper presents the problems in translating post-1950 African American poetry into Slovene, and asks to what extent can one successfully transfer the musical elements within this poetry for the target culture? Inevitably, it will identify a share of elements that are lost in translation.

Whole genome characterization of human influenza A(H1N1)pdm09 viruses isolated from Kenya during the 2009 pandemic.

Science.gov (United States)

Gachara, George; Symekher, Samuel; Otieno, Michael; Magana, Japheth; Opot, Benjamin; Bulimo, Wallace

2016-06-01

An influenza pandemic caused by a novel influenza virus A(H1N1)pdm09 spread worldwide in 2009 and is estimated to have caused between 151,700 and 575,400 deaths globally. While whole genome data on new virus enables a deeper insight in the pathogenesis, epidemiology, and drug sensitivities of the circulating viruses, there are relatively limited complete genetic sequences available for this virus from African countries. We describe herein the full genome analysis of influenza A(H1N1)pdm09 viruses isolated in Kenya between June 2009 and August 2010. A total of 40 influenza A(H1N1)pdm09 viruses isolated during the pandemic were selected. The segments from each isolate were amplified and directly sequenced. The resulting sequences of individual gene segments were concatenated and used for subsequent analysis. These were used to infer phylogenetic relationships and also to reconstruct the time of most recent ancestor, time of introduction into the country, rates of substitution and to estimate a time-resolved phylogeny. The Kenyan complete genome sequences clustered with globally distributed clade 2 and clade 7 sequences but local clade 2 viruses did not circulate beyond the introductory foci while clade 7 viruses disseminated country wide. The time of the most recent common ancestor was estimated between April and June 2009, and distinct clusters circulated during the pandemic. The complete genome had an estimated rate of nucleotide substitution of 4.9×10(-3) substitutions/site/year and greater diversity in surface expressed proteins was observed. We show that two clades of influenza A(H1N1)pdm09 virus were introduced into Kenya from the UK and the pandemic was sustained as a result of importations. Several closely related but distinct clusters co-circulated locally during the peak pandemic phase but only one cluster dominated in the late phase of the pandemic suggesting that it possessed greater adaptability. Copyright © 2016 Elsevier B.V. All rights reserved.

Strategic management of livestock to improve biodiversity conservation in African savannahs: A conceptual basis for wildlife-livestock coexistence

Science.gov (United States)

African savannas are complex socio-ecological systems with diverse wild and domestic herbivore assemblages, which utilize functional heterogeneity of habitats to adapt to intra- and inter-annual variation in forage quantity and quality, predation and disease risks. As African savannas become increas...

CD11c controls herpes simplex virus 1 responses to limit virus replication during primary infection.

Science.gov (United States)

Allen, Sariah J; Mott, Kevin R; Chentoufi, Aziz A; BenMohamed, Lbachir; Wechsler, Steven L; Ballantyne, Christie M; Ghiasi, Homayon

2011-10-01

CD11c is expressed on the surface of dendritic cells (DCs) and is one of the main markers for identification of DCs. DCs are the effectors of central innate immune responses, but they also affect acquired immune responses to infection. However, how DCs influence the efficacy of adaptive immunity is poorly understood. Here, we show that CD11c(+) DCs negatively orchestrate both adaptive and innate immunity against herpes simplex virus type 1 (HSV-1) ocular infection. The effectiveness and quantity of virus-specific CD8(+) T cell responses are increased in CD11c-deficient animals. In addition, the levels of CD83, CD11b, alpha interferon (IFN-α), and IFN-β, but not IFN-γ, were significantly increased in CD11c-deficient animals. Higher levels of IFN-α, IFN-β, and CD8(+) T cells in the CD11c-deficient mice may have contributed to lower virus replication in the eye and trigeminal ganglia (TG) during the early period of infection than in wild-type mice. However, the absence of CD11c did not influence survival, severity of eye disease, or latency. Our studies provide for the first time evidence that CD11c expression may abrogate the ability to reduce primary virus replication in the eye and TG via higher activities of type 1 interferon and CD8(+) T cell responses.

Virulence determinants of pandemic influenza viruses

Science.gov (United States)

Tscherne, Donna M.; García-Sastre, Adolfo

2011-01-01

Influenza A viruses cause recurrent, seasonal epidemics and occasional global pandemics with devastating levels of morbidity and mortality. The ability of influenza A viruses to adapt to various hosts and undergo reassortment events ensures constant generation of new strains with unpredictable degrees of pathogenicity, transmissibility, and pandemic potential. Currently, the combination of factors that drives the emergence of pandemic influenza is unclear, making it impossible to foresee the details of a future outbreak. Identification and characterization of influenza A virus virulence determinants may provide insight into genotypic signatures of pathogenicity as well as a more thorough understanding of the factors that give rise to pandemics. PMID:21206092

Genetic Variation and Adaptation in Africa: Implications for Human Evolution and Disease

Science.gov (United States)

Gomez, Felicia; Hirbo, Jibril; Tishkoff, Sarah A.

2014-01-01

Because modern humans originated in Africa and have adapted to diverse environments, African populations have high levels of genetic and phenotypic diversity. Thus, genomic studies of diverse African ethnic groups are essential for understanding human evolutionary history and how this leads to differential disease risk in all humans. Comparative studies of genetic diversity within and between African ethnic groups creates an opportunity to reconstruct some of the earliest events in human population history and are useful for identifying patterns of genetic variation that have been influenced by recent natural selection. Here we describe what is currently known about genetic variation and evolutionary history of diverse African ethnic groups. We also describe examples of recent natural selection in African genomes and how these data are informative for understanding the frequency of many genetic traits, including those that cause disease susceptibility in African populations and populations of recent African descent. PMID:24984772

Molecular evolution and thermal adaptation

Science.gov (United States)

Chen, Peiqiu

2011-12-01

In this thesis, we address problems in molecular evolution, thermal adaptation, and the kinetics of adaptation of bacteria and viruses to elevated environmental temperatures. We use a nearly neutral fitness model where the replication speed of an organism is proportional to the copy number of folded proteins. Our model reproduces the distribution of stabilities of natural proteins in excellent agreement with experiment. We find that species with high mutation rates tend to have less stable proteins compared to species with low mutation rate. We found that a broad distribution of protein stabilities observed in the model and in experiment is the key determinant of thermal response for viruses and bacteria. Our results explain most of the earlier experimental observations: striking asymmetry of thermal response curves, the absence of evolutionary trade-off which was expected but not found in experiments, correlation between denaturation temperature for several protein families and the Optimal Growth Temperature (OGT) of their carrier organisms, and proximity of bacterial or viral OGTs to their evolutionary temperatures. Our theory quantitatively and with high accuracy described thermal response curves for 35 bacterial species. The model also addresses the key to adaptation is in weak-link genes (WLG), which encode least thermodynamically stable essential proteins in the proteome. We observe, as in experiment, a two-stage adaptation process. The first stage is a Luria-Delbruck type of selection, whereby rare WLG alleles, whose proteins are more stable than WLG proteins of the majority of the population (either due to standing genetic variation or due to an early acquired mutation), rapidly rise to fixation. The second stage constitutes subsequent slow accumulation of mutations in an adapted population. As adaptation progresses, selection regime changes from positive to neutral: Selection coefficient of beneficial mutations scales as a negative power of number of

Biotechnological approaches to determine the impact of viruses in the energy crop plant Jatropha curcas

Science.gov (United States)

2011-01-01

Background Geminiviruses infect a wide range of plant species including Jatropha and cassava both belonging to family Euphorbiaceae. Cassava is traditionally an important food crop in Sub - Saharan countries, while Jatropha is considered as valuable biofuel plant with great perspectives in the future. Results A total of 127 Jatropha samples from Ethiopia and Kenya and 124 cassava samples from Kenya were tested by Enzyme-Linked Immunosorbent Assay (ELISA) for RNA viruses and polymerase chain reaction for geminiviruses. Jatropha samples from 4 different districts in Kenya and Ethiopia (analyzed by ELISA) were negative for all three RNA viruses tested: Cassava brown streak virus (CBSV), Cassava common mosaic virus, Cucumber mosaic virus, Three cassava samples from Busia district (Kenya) contained CBSV. Efforts to develop diagnostic approaches allowing reliable pathogen detection in Jatropha, involved the amplification and sequencing of the entire DNA A molecules of 40 Kenyan isolates belonging to African cassava mosaic virus (ACMV) and East African cassava mosaic virus - Uganda. This information enabled the design of novel primers to address different questions: a) primers amplifying longer sequences led to a phylogenetic tree of isolates, allowing some predictions on the evolutionary aspects of Begomoviruses in Jatrophia; b) primers amplifying shorter sequences represent a reliable diagnostic tool. This is the first report of the two Begomoviruses in J. curcas. Two cassava samples were co - infected with cassava mosaic geminivirus and CBSV. A Defective DNA A of ACMV was found for the first time in Jatropha. Conclusion Cassava geminiviruses occurring in Jatropha might be spread wider than anticipated. If not taken care of, this virus infection might negatively impact large scale plantations for biofuel production. Being hosts for similar pathogens, the planting vicinity of the two crop plants needs to be handled carefully. PMID:21812981

Biotechnological approaches to determine the impact of viruses in the energy crop plant Jatropha curcas

Directory of Open Access Journals (Sweden)

Maghuly Fatemeh

2011-08-01

Full Text Available Abstract Background Geminiviruses infect a wide range of plant species including Jatropha and cassava both belonging to family Euphorbiaceae. Cassava is traditionally an important food crop in Sub - Saharan countries, while Jatropha is considered as valuable biofuel plant with great perspectives in the future. Results A total of 127 Jatropha samples from Ethiopia and Kenya and 124 cassava samples from Kenya were tested by Enzyme-Linked Immunosorbent Assay (ELISA for RNA viruses and polymerase chain reaction for geminiviruses. Jatropha samples from 4 different districts in Kenya and Ethiopia (analyzed by ELISA were negative for all three RNA viruses tested: Cassava brown streak virus (CBSV, Cassava common mosaic virus, Cucumber mosaic virus, Three cassava samples from Busia district (Kenya contained CBSV. Efforts to develop diagnostic approaches allowing reliable pathogen detection in Jatropha, involved the amplification and sequencing of the entire DNA A molecules of 40 Kenyan isolates belonging to African cassava mosaic virus (ACMV and East African cassava mosaic virus - Uganda. This information enabled the design of novel primers to address different questions: a primers amplifying longer sequences led to a phylogenetic tree of isolates, allowing some predictions on the evolutionary aspects of Begomoviruses in Jatrophia; b primers amplifying shorter sequences represent a reliable diagnostic tool. This is the first report of the two Begomoviruses in J. curcas. Two cassava samples were co - infected with cassava mosaic geminivirus and CBSV. A Defective DNA A of ACMV was found for the first time in Jatropha. Conclusion Cassava geminiviruses occurring in Jatropha might be spread wider than anticipated. If not taken care of, this virus infection might negatively impact large scale plantations for biofuel production. Being hosts for similar pathogens, the planting vicinity of the two crop plants needs to be handled carefully.

Avian influenza viruses in humans.

Science.gov (United States)

Malik Peiris, J S

2009-04-01

Past pandemics arose from low pathogenic avian influenza (LPAI) viruses. In more recent times, highly pathogenic avian influenza (HPAI) H5N1, LPAI H9N2 and both HPAI and LPAI H7 viruses have repeatedly caused zoonotic disease in humans. Such infections did not lead to sustained human-to-human transmission. Experimental infection of human volunteers and seroepidemiological studies suggest that avian influenza viruses of other subtypes may also infect humans. Viruses of the H7 subtype appear to have a predilection to cause conjunctivitis and influenza-like illness (ILI), although HPAI H7N7 virus has also caused fatal respiratory disease. Low pathogenic H9N2 viruses have caused mild ILI and its occurrence may be under-recognised for this reason. In contrast, contemporary HPAI H5N1 viruses are exceptional in their virulence for humans and differ from human seasonal influenza viruses in their pathogenesis. Patients have a primary viral pneumonia progressing to acute respiratory distress syndrome (ARDS) and multiple organ dysfunction syndrome. Over 380 human cases have been confirmed to date, with an overall case fatality of 63%. The zoonotic transmission of avian influenza is a rare occurrence, butthe greater public health concern is the adaptation of such viruses to efficient human transmission, which could lead to a pandemic. A better understanding of the ecology of avian influenza viruses and the biological determinants of transmissibility and pathogenicity in humans is important for pandemic preparedness.

Searching for the Advantages of Virus Sex

Science.gov (United States)

Turner, Paul E.

2003-02-01

Sex (genetic exchange) is a nearly universal phenomenon in biological populations. But this is surprising given the costs associated with sex. For example, sex tends to break apart co-adapted genes, and sex causes a female to inefficiently contribute only half the genes to her offspring. Why then did sex evolve? One famous model poses that sex evolved to combat Muller's ratchet, the mutational load that accrues when harmful mutations drift to high frequencies in populations of small size. In contrast, the Fisher-Muller Hypothesis predicts that sex evolved to promote genetic variation that speeds adaptation in novel environments. Sexual mechanisms occur in viruses, which feature high rates of deleterious mutation and frequent exposure to novel or changing environments. Thus, confirmation of one or both hypotheses would shed light on the selective advantages of virus sex. Experimental evolution has been used to test these classic models in the RNA bacteriophage φ6, a virus that experiences sex via reassortment of its chromosomal segments. Empirical data suggest that sex might have originated in φ6 to assist in purging deleterious mutations from the genome. However, results do not support the idea that sex evolved because it provides beneficial variation in novel environments. Rather, experiments show that too much sex can be bad for φ6 promiscuity allows selfish viruses to evolve and spread their inferior genes to subsequent generations. Here I discuss various explanations for the evolution of segmentation in RNA viruses, and the added cost of sex when large numbers of viruses co-infect the same cell.

Immune responses to influenza virus and its correlation to age and inherited factors

Directory of Open Access Journals (Sweden)

Azadeh Bahadoran

2016-11-01

Full Text Available Influenza viruses belong to the family Orthomyxoviridae of enveloped viruses and are an important cause of respiratory infections worldwide. The influenza virus is able to infect a wide variety species as diverse as poultry, marine, pigs, horses and humans. Upon infection with influenza virus the innate immunity plays a critical role in efficient and rapid control of viral infections as well as in adaptive immunity initiation. The humoral immune system produces antibodies against different influenza antigens, of which the HA-specific antibody is the most important for neutralization of the virus and thus prevention of illness. Cell mediated immunity including CD4+ helper T cells and CD8+ cytotoxic T cells are the other arms of adaptive immunity induced upon influenza virus infection. The complex inherited factors and age related changes are associated with the host immune responses. Here, we review the different components of immune responses against influenza virus. Additionally, the correlation of the immune response to age and inherited factors has been discussed. These determinations lead to a better understanding of the limitations of immune responses for developing improved vaccines to control influenza virus infection.

Canine distemper virus in the Serengeti ecosystem: molecular adaptation to different carnivore species.

Science.gov (United States)

Nikolin, Veljko M; Olarte-Castillo, Ximena A; Osterrieder, Nikolaus; Hofer, Heribert; Dubovi, Edward; Mazzoni, Camila J; Brunner, Edgar; Goller, Katja V; Fyumagwa, Robert D; Moehlman, Patricia D; Thierer, Dagmar; East, Marion L

2017-04-01

Was the 1993/1994 fatal canine distemper virus (CDV) epidemic in lions and spotted hyaenas in the Serengeti ecosystem caused by the recent spillover of a virulent domestic dog strain or one well adapted to these noncanids? We examine this question using sequence data from 13 'Serengeti' strains including five complete genomes obtained between 1993 and 2011. Phylogenetic and haplotype network analyses reveal that strains from noncanids during the epidemic were more closely related to each other than to those from domestic or wild canids. All noncanid 'Serengeti' strains during the epidemic encoded: (1) one novel substitution G134S in the CDV-V protein; and (2) the rare amino acid combination 519I/549H at two sites under positive selection in the region of the CDV-H protein that binds to SLAM (CD 150) host cell receptors. Worldwide, only a few noncanid strains in the America II lineage encode CDV-H 519I/549H. All canid 'Serengeti' strains during the epidemic coded CDV-V 134G, and CDV-H 519R/549Y, or 519R/549H. A functional assay of cell entry revealed the highest performance by CDV-H proteins encoding 519I/549H in cells expressing lion SLAM receptors, and the highest performance by proteins encoding 519R/549Y, typical of dog strains worldwide, in cells expressing dog SLAM receptors. Our findings are consistent with an epidemic in lions and hyaenas caused by CDV variants better adapted to noncanids than canids, but not with the recent spillover of a dog strain. Our study reveals a greater complexity of CDV molecular epidemiology in multihost environments than previously thought. © 2016 John Wiley & Sons Ltd.

Adaptation of tick-borne encephalitis virus from human brain to different cell cultures induces multiple genomic substitutions.

Science.gov (United States)

Ponomareva, Eugenia P; Ternovoi, Vladimir A; Mikryukova, Tamara P; Protopopova, Elena V; Gladysheva, Anastasia V; Shvalov, Alexander N; Konovalova, Svetlana N; Chausov, Eugene V; Loktev, Valery B

2017-10-01

The C11-13 strain from the Siberian subtype of tick-borne encephalitis virus (TBEV) was isolated from human brain using pig embryo kidney (PEK), 293, and Neuro-2a cells. Analysis of the complete viral genome of the C11-13 variants during six passages in these cells revealed that the cell-adapted C11-13 variants had multiple amino acid substitutions as compared to TBEV from human brain. Seven out of eight amino acids substitutions in the high-replicating C11-13(PEK) variant mapped to non-structural proteins; 13 out of 14 substitutions in the well-replicating C11-13(293) variant, and all four substitutions in the low-replicating C11-13(Neuro-2a) variant were also localized in non-structural proteins, predominantly in the NS2a (2), NS3 (6) and NS5 (3) proteins. The substitutions NS2a 1067 (Asn → Asp), NS2a 1168 (Leu → Val) in the N-terminus of NS2a and NS3 1745 (His → Gln) in the helicase domain of NS3 were found in all selected variants. We postulate that multiple substitutions in the NS2a, NS3 and NS5 genes play a key role in adaptation of TBEV to different cells.

Adapting the SCOR model to suit the military: A South African example

CSIR Research Space (South Africa)

Bean, WL

2009-09-01

Full Text Available of military supply chains, therefore it was decided that supply chain management in conjunction with the SCOR model should be used during a logistics and supply chain improvement project for the South African National Defence Force (SANDF). Three case studies...

Strengthening the abilities of French-speaking NGOs. Post-2012 climate stakes. Adaptation - Energy - Deforestation, France - Africa - Canada

International Nuclear Information System (INIS)

Creach, Morgane; Margot, Stephanie; Connor, Richard; Angerand, Sylvain

2007-10-01

The first part of this report discusses the possibilities of an international response to face the challenge of adaptation to climate change (presentation of the main notions, discussion of the United Nations Framework Convention on Climate Change and international stakes about adaptation). The second part discusses the perspectives of access to energy in African countries: description of the African energy context, applications of existing mechanisms of struggle against climate change to the field of energy, stakes for post-2012 negotiations. The next part addresses the stakes of the avoided deforestation: definitions and key figures, direct and underlying causes of deforestation and assessment of the cost for slowing down or stopping it, stakes and struggle of interests about the 'avoided deforestation'. The last part reports the 'post-2012 climate stakes' workshop which addressed these same topics (access to energy in African countries, adaptation to climate change, avoided deforestation)

The COP22 in Africa. Is the African group of negotiators in tune?

International Nuclear Information System (INIS)

Maupin, Agathe

2016-01-01

As the COP22 is about to take place in an African country (Morocco), the author discusses how African countries deal with the fact that they belong to different negotiation groups, and which are the strategies adopted until now by the group of African negotiators to cope with the delicate combination of national requests and continental vision. Thus, the author recalls and comments the positions adopted since COP1 by the five groups of negotiators and their relationships with different international bodies. She discuses the posture and strategies of African countries, and how to gather them about topics of common interest such as adaptation, financing and transfer of capacities and technologies. She also comments the emergence of a new strategy regarding financing mechanisms

Phenotypic plasticity and local adaptation in two extreme ...

African Journals Online (AJOL)

Principal coordinate analysis (PCoA) of allozymes revealed little genetic overlap among populations. Keywords: allozyme, genotype×environment interaction, genetic variation, local adaptation, reaction norms, starch gel electrophoresis, trade-off. African Journal of Range & Forage Science 2008, 25(3): 121–130 ...

Experimental Treatment of Ebola Virus Disease with Brincidofovir.

Directory of Open Access Journals (Sweden)

Jake Dunning

Full Text Available The nucleotide analogue brincidofovir was developed to prevent and treat infections caused by double-stranded DNA viruses. Based on in vitro data suggesting an antiviral effect against Ebola virus, brincidofovir was included in the World Health Organisation list of agents that should be prioritised for clinical evaluation in patients with Ebola virus disease (EVD during the West African epidemic.In this single-arm phase 2 trial conducted in Liberia, patients with laboratory-confirmed EVD (two months of age or older, enrolment bodyweight ≥50 kg received oral brincidofovir 200 mg as a loading dose on day 0, followed by 100 mg brincidofovir on days 3, 7, 10, and 14. Bodyweight-adjusted dosing was used for patients weighing <50 kg at enrolment. The primary outcome was survival at Day 14 after the first dose of brincidofovir. Four patients were enrolled between 01 January 2015 and 31 January 2015. The trial was stopped following the decision by the manufacturer to terminate their program of development of brincidofovir for EVD. No Serious Adverse Reactions or Suspected Unexpected Serious Adverse Reactions were identified. All enrolled subjects died of an illness consistent with EVD.Due to the small sample size it was not possible to determine the efficacy of brincidofovir for the treatment of EVD. The premature termination of the trial highlights the need to establish better practices for preclinical in-vitro and animal screening of therapeutics for potentially emerging epidemic infectious diseases prior to their use in patients.Pan African Clinical Trials Registry PACTR201411000939962.

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...... in adaptive responses to oxidative stress by removing excessive Ca2+ from the cytosol, and that their functional expression is significantly altered in PVX-inoculated plants. These findings highlight the crucial role of Ca2+ efflux systems in acquired tolerance to oxidative stress and open up prospects...... stress in Nicotiana benthamiana and showed the critical role of plasma membrane Ca2+/H+ exchangers in this process. The current study continues this research. Using biochemical and electrophysiological approaches, we reveal that both endomembrane P2A and P2B Ca2+-ATPases play significant roles...

Hepatitis B and hepatitis D virus infections in the Central African Republic, twenty-five years after a fulminant hepatitis outbreak, indicate continuing spread in asymptomatic young adults.

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Narcisse Patrice Komas

2018-04-01

Full Text Available Hepatitis delta virus (HDV increases morbidity in Hepatitis B virus (HBV-infected patients. In the mid-eighties, an outbreak of HDV fulminant hepatitis (FH in the Central African Republic (CAR killed 88% of patients hospitalized in Bangui. We evaluated infections with HBV and HDV among students and pregnant women, 25 years after the fulminant hepatitis (FH outbreak to determine (i the prevalence of HBV and HDV infection in this population, (ii the clinical risk factors for HBV and/or HDV infections, and (iii to characterize and compare the strains from the FH outbreak in the 1980s to the 2010 HBV-HDV strains. We performed a cross sectional study with historical comparison on FH-stored samples (n = 179 from 159 patients and dried blood-spots from volunteer students and pregnant women groups (n = 2172. We analyzed risk factors potentially associated with HBV and HDV. Previous HBV infection (presence of anti-HBc occurred in 345/1290 students (26.7% and 186/870 pregnant women (21.4%(p = 0.005, including 110 students (8.8% and 71 pregnant women (8.2%, who were also HBsAg-positive (p = 0.824. HDV infection occurred more frequently in pregnant women (n = 13; 18.8% than students (n = 6; 5.4% (p = 0.010. Infection in childhood was probably the main HBV risk factor. The risk factors for HDV infection were age (p = 0.040, transfusion (p = 0.039, and a tendency for tattooing (p = 0.055 and absence of condom use (p = 0.049. HBV-E and HDV-1 were highly prevalent during both the FH outbreak and the 2010 screening project. For historical samples, due to storage conditions and despite several attempts, we could only obtain partial HDV amplification representing 25% of the full-length genome. The HDV-1 mid-eighties FH-strains did not form a specific clade and were affiliated to two different HDV-1 African subgenotypes, one of which also includes the 2010 HDV-1 strains. In the Central African Republic, these findings indicate a high prevalence of previous and

Dynamical Models for Computer Viruses Propagation

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José R. C. Piqueira

2008-01-01

Full Text Available Nowadays, digital computer systems and networks are the main engineering tools, being used in planning, design, operation, and control of all sizes of building, transportation, machinery, business, and life maintaining devices. Consequently, computer viruses became one of the most important sources of uncertainty, contributing to decrease the reliability of vital activities. A lot of antivirus programs have been developed, but they are limited to detecting and removing infections, based on previous knowledge of the virus code. In spite of having good adaptation capability, these programs work just as vaccines against diseases and are not able to prevent new infections based on the network state. Here, a trial on modeling computer viruses propagation dynamics relates it to other notable events occurring in the network permitting to establish preventive policies in the network management. Data from three different viruses are collected in the Internet and two different identification techniques, autoregressive and Fourier analyses, are applied showing that it is possible to forecast the dynamics of a new virus propagation by using the data collected from other viruses that formerly infected the network.

Deep-Sea Hydrothermal Vent Viruses Compensate for Microbial Metabolism in Virus-Host Interactions.

Science.gov (United States)

He, Tianliang; Li, Hongyun; Zhang, Xiaobo

2017-07-11

that viral genes not only participated in most microbial metabolic pathways but also formed branched pathways in microbial metabolisms. The metabolic compensation of hosts mediated by viruses may help hosts to adapt to extreme environments and may be essential for host survival. Copyright © 2017 He et al.

[Zika virus infection or the future of infectious diseases].

Science.gov (United States)

Valerio Sallent, Lluís; Roure Díez, Sílvia; Fernández Rivas, Gema

2016-10-07

Zika virus belongs to the Flaviridae, an extended phylogenetic family containing dengue or yellow fever, viruses whose shared main vector are Aedes aegypti mosquitoes. The virus originally came from Central African simian reservoirs and, from there, expanded rapidly across the Pacific to South America. The disease is an example of exantematic fever usually mild. Mortality is very low and mainly limited to secondary Guillain-Barré or fetal microcephaly cases. Diagnostic confirmation requires a RT-PCR in blood up to the 5th day from the onset or in urine up to the 10-14th day. Specific IgM are identifiable from the 5th symptomatic day. Clinically, a suspected case should comply with: a) a journey to epidemic areas; b) a clinically compatible appearance with fever and skin rash, and c) a generally normal blood count/basic biochemistry. There is some evidence that causally relates Zika virus infection with fetal microcephaly. While waiting for definitive data, all pregnant women coming from Central or South America should be tested for Zika virus. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

Genetic determinism and evolutionary reconstruction of a host jump in a plant virus

DEFF Research Database (Denmark)

Vassilakos, Nikon; Simon, Vincent; Tzima, Aliki

2016-01-01

In spite of their widespread occurrence, only few host jumps by plant viruses have been evidenced and the molecular bases of even fewer have been determined. A combination of three independent approaches, 1) experimental evolution followed by reverse genetics analysis, 2) positive selection...... analysis, and 3) locus-by-locus analysis of molecular variance (AMOVA) allowed reconstructing the Potato virus Y (PVY; genus Potyvirus, family Potyviridae) jump to pepper (Capsicum annuum), probably from other solanaceous plants. Synthetic chimeras between infectious cDNA clones of two PVY isolates...... independently and conferred adaptation to C. annuum. In addition to increasing our knowledge of host jumps in plant viruses, this study illustrates also the efficiency of locus-by-locus AMOVA and combined approaches to identify adaptive mutations in the genome of RNA viruses....

Use of SLAM and PVRL4 and identification of pro-HB-EGF as cell entry receptors for wild type phocine distemper virus.

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Mary M Melia

Full Text Available Signalling lymphocyte activation molecule (SLAM has been identified as an immune cell receptor for the morbilliviruses, measles (MV, canine distemper (CDV, rinderpest and peste des petits ruminants (PPRV viruses, while CD46 is a receptor for vaccine strains of MV. More recently poliovirus like receptor 4 (PVRL4, also known as nectin 4, has been identified as a receptor for MV, CDV and PPRV on the basolateral surface of polarised epithelial cells. PVRL4 is also up-regulated by MV in human brain endothelial cells. Utilisation of PVRL4 as a receptor by phocine distemper virus (PDV remains to be demonstrated as well as confirmation of use of SLAM. We have observed that unlike wild type (wt MV or wtCDV, wtPDV strains replicate in African green monkey kidney Vero cells without prior adaptation, suggesting the use of a further receptor. We therefore examined candidate molecules, glycosaminoglycans (GAG and the tetraspan proteins, integrin β and the membrane bound form of heparin binding epithelial growth factor (proHB-EGF,for receptor usage by wtPDV in Vero cells. We show that wtPDV replicates in Chinese hamster ovary (CHO cells expressing SLAM and PVRL4. Similar wtPDV titres are produced in Vero and VeroSLAM cells but more limited fusion occurs in the latter. Infection of Vero cells was not inhibited by anti-CD46 antibody. Removal/disruption of GAG decreased fusion but not the titre of virus. Treatment with anti-integrin β antibody increased rather than decreased infection of Vero cells by wtPDV. However, infection was inhibited by antibody to HB-EGF and the virus replicated in CHO-proHB-EGF cells, indicating use of this molecule as a receptor. Common use of SLAM and PVRL4 by morbilliviruses increases the possibility of cross-species infection. Lack of a requirement for wtPDV adaptation to Vero cells raises the possibility of usage of proHB-EGF as a receptor in vivo but requires further investigation.

CRISPR-Cas : Adapting to change

NARCIS (Netherlands)

Jackson, Simon A.; McKenzie, R.E.; Fagerlund, Robert D.; Kieper, S.N.; Fineran, Peter C.; Brouns, S.J.J.

2017-01-01

Bacteria and archaea are engaged in a constant arms race to defend against the ever-present threats of viruses and invasion by mobile genetic elements. The most flexible weapons in the prokaryotic defense arsenal are the CRISPR-Cas adaptive immune systems. These systems are capable of selective

Fight Ebola virus disease in Africa: a question related to the ...

African Journals Online (AJOL)

Repetitive outbreaks of Ebola virus disease is a major public health problem in Africa. Indeed, since September 1976, date of its isolation and its first description in the north of the ex-Zaire (now Democratic Republic of Congo) and in the south Sudan, many African countries continue to live recurring episodes of epidemics ...

Perfectionism in African American students: relationship to racial identity, GPA, self-esteem, and depression.

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Elion, Audrey A; Wang, Kenneth T; Slaney, Robert B; French, Bryana H

2012-04-01

This study examined 219 African American college students at predominantly White universities using the constructs of perfectionism, academic achievement, self-esteem, depression, and racial identity. Cluster analysis was performed using the Almost Perfect Scale-Revised (APS-R), which yielded three clusters that represented adaptive perfectionists, maladaptive perfectionists, and nonperfectionists. These three groups were compared on their scores on the Rosenberg Self-Esteem Scale (RSES), the Center for Epidemiological Studies-Depression Scale (CES-D), the Cross Racial Identity Scale (CRIS), and Grade Point Average (GPA). Adaptive perfectionists reported higher self-esteem and lower depression scores than both the nonperfectionists and maladaptive perfectionists. Adaptive perfectionists had higher GPAs than nonperfectionists. On the racial identity scales, maladaptive perfectionists had higher scores on Pre-Encounter Self Hatred and Immersion-Emersion Anti-White subscales than adaptive perfectionists. The cultural and counseling implications of this study are discussed and integrated. Finally, recommendations are made for future studies of African American college students and perfectionism. PsycINFO Database Record (c) 2012 APA, all rights reserved.

THE STRENGTHS, WEAKNESSES, OPPORTUNITIES, AND THREATS (SWOTs) ANALYSES OF THE EBOLA VIRUS ? PAPER RETRACTED

OpenAIRE

Babalola, Michael Oluyemi

2016-01-01

Background: Owing to the extreme virulence and case fatality rate of ebola virus disease (EVD), there had been so much furore, panic and public health emergency about the possible pandemic from the recent West African outbreak of the disease, with attendant handful research, both in the past and most recently. The magnitude of the epidemic of ebola virus disease has prompted global interest and urgency in the discovery of measures to mitigate the impact of the disease. Researchers in the acad...

Recombinant measles virus vaccine expressing the Nipah virus glycoprotein protects against lethal Nipah virus challenge.

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Misako Yoneda

Full Text Available Nipah virus (NiV is a member of the genus Henipavirus, which emerged in Malaysia in 1998. In pigs, infection resulted in a predominantly non-lethal respiratory disease; however, infection in humans resulted in over 100 deaths. Nipah virus has continued to re-emerge in Bangladesh and India, and person-to-person transmission appeared in the outbreak. Although a number of NiV vaccine studies have been reported, there are currently no vaccines or treatments licensed for human use. In this study, we have developed a recombinant measles virus (rMV vaccine expressing NiV envelope glycoproteins (rMV-HL-G and rMV-Ed-G. Vaccinated hamsters were completely protected against NiV challenge, while the mortality of unvaccinated control hamsters was 90%. We trialed our vaccine in a non-human primate model, African green monkeys. Upon intraperitoneal infection with NiV, monkeys showed several clinical signs of disease including severe depression, reduced ability to move and decreased food ingestion and died at 7 days post infection (dpi. Intranasal and oral inoculation induced similar clinical illness in monkeys, evident around 9 dpi, and resulted in a moribund stage around 14 dpi. Two monkeys immunized subcutaneously with rMV-Ed-G showed no clinical illness prior to euthanasia after challenge with NiV. Viral RNA was not detected in any organ samples collected from vaccinated monkeys, and no pathological changes were found upon histopathological examination. From our findings, we propose that rMV-NiV-G is an appropriate NiV vaccine candidate for use in humans.

Enhancement of the safety of live influenza vaccine by attenuating mutations from cold-adapted hemagglutinin

International Nuclear Information System (INIS)

Lee, Yoon Jae; Jang, Yo Han; Kim, Paul; Lee, Yun Ha; Lee, Young Jae; Byun, Young Ho; Lee, Kwang-Hee; Kim, Kyusik; Seong, Baik Lin

2016-01-01

In our previous study, X-31ca-based H5N1 LAIVs, in particular, became more virulent in mice than the X-31ca MDV, possibly by the introduction of the surface antigens of highly pathogenic H5N1 influenza virus, implying that additional attenuation is needed in this cases to increase the safety level of the vaccine. In this report we suggest an approach to further increase the safety of LAIV through additional cold-adapted mutations in the hemagglutinin. The cold-adaptation of X-31 virus resulted in four amino acid mutations in the HA. We generated a panel of 7:1 reassortant viruses each carrying the hemagglutinins with individual single amino acid mutations. We examined their phenotypes and found a major attenuating mutation, N81K. This attenuation marker conferred additional temperature-sensitive and attenuation phenotype to the LAIV. Our data indicate that the cold-adapted mutation in the HA confers additional attenuation to the LAIV strain, without compromising its productivity and immune response. - Highlights: • Cold-adaptation process induced four amino acid mutations in the HA of X-31 virus. • The four mutations in the HA also contributed to attenuation of the X-31ca virus • N81K mutation was the most significant marker for the attenuation of X-31ca virus. • Introduction of N81K mutation into H3N2 LAIV further attenuated the vaccine. • This approach provides a useful guideline for enhancing the safety of the LAIVs.

Enhancement of the safety of live influenza vaccine by attenuating mutations from cold-adapted hemagglutinin

Energy Technology Data Exchange (ETDEWEB)

Lee, Yoon Jae [Graduate Program in Biomaterials Science and Engineering, College of Life Science and Biotechnology, Yonsei University, Seoul (Korea, Republic of); Laboratory of Molecular Medicine, Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul (Korea, Republic of); Vaccine Translational Research Center, Yonsei University, Seoul (Korea, Republic of); Jang, Yo Han [Laboratory of Molecular Medicine, Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul (Korea, Republic of); Kim, Paul; Lee, Yun Ha; Lee, Young Jae [Laboratory of Molecular Medicine, Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul (Korea, Republic of); Vaccine Translational Research Center, Yonsei University, Seoul (Korea, Republic of); Byun, Young Ho; Lee, Kwang-Hee; Kim, Kyusik [Laboratory of Molecular Medicine, Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul (Korea, Republic of); Seong, Baik Lin, E-mail: blseong@yonsei.ac.kr [Graduate Program in Biomaterials Science and Engineering, College of Life Science and Biotechnology, Yonsei University, Seoul (Korea, Republic of); Laboratory of Molecular Medicine, Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul (Korea, Republic of); Vaccine Translational Research Center, Yonsei University, Seoul (Korea, Republic of)

2016-04-15

In our previous study, X-31ca-based H5N1 LAIVs, in particular, became more virulent in mice than the X-31ca MDV, possibly by the introduction of the surface antigens of highly pathogenic H5N1 influenza virus, implying that additional attenuation is needed in this cases to increase the safety level of the vaccine. In this report we suggest an approach to further increase the safety of LAIV through additional cold-adapted mutations in the hemagglutinin. The cold-adaptation of X-31 virus resulted in four amino acid mutations in the HA. We generated a panel of 7:1 reassortant viruses each carrying the hemagglutinins with individual single amino acid mutations. We examined their phenotypes and found a major attenuating mutation, N81K. This attenuation marker conferred additional temperature-sensitive and attenuation phenotype to the LAIV. Our data indicate that the cold-adapted mutation in the HA confers additional attenuation to the LAIV strain, without compromising its productivity and immune response. - Highlights: • Cold-adaptation process induced four amino acid mutations in the HA of X-31 virus. • The four mutations in the HA also contributed to attenuation of the X-31ca virus • N81K mutation was the most significant marker for the attenuation of X-31ca virus. • Introduction of N81K mutation into H3N2 LAIV further attenuated the vaccine. • This approach provides a useful guideline for enhancing the safety of the LAIVs.

African Journals Online: Central African Republic

African Journals Online (AJOL)

African Journals Online: Central African Republic. Home > African Journals Online: Central African Republic. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Browse By Category · Browse Alphabetically · Browse By Country · List All Titles · Free to read Titles This ...

A novel Zika virus mouse model reveals strain specific differences in virus pathogenesis and host inflammatory immune responses.

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Shashank Tripathi

2017-03-01

Full Text Available Zika virus (ZIKV is a mosquito borne flavivirus, which was a neglected tropical pathogen until it emerged and spread across the Pacific Area and the Americas, causing large human outbreaks associated with fetal abnormalities and neurological disease in adults. The factors that contributed to the emergence, spread and change in pathogenesis of ZIKV are not understood. We previously reported that ZIKV evades cellular antiviral responses by targeting STAT2 for degradation in human cells. In this study, we demonstrate that Stat2-/- mice are highly susceptible to ZIKV infection, recapitulate virus spread to the central nervous system (CNS, gonads and other visceral organs, and display neurological symptoms. Further, we exploit this model to compare ZIKV pathogenesis caused by a panel of ZIKV strains of a range of spatiotemporal history of isolation and representing African and Asian lineages. We observed that African ZIKV strains induce short episodes of severe neurological symptoms followed by lethality. In comparison, Asian strains manifest prolonged signs of neuronal malfunctions, occasionally causing death of the Stat2-/- mice. African ZIKV strains induced higher levels of inflammatory cytokines and markers associated with cellular infiltration in the infected brain in mice, which may explain exacerbated pathogenesis in comparison to those of the Asian lineage. Interestingly, viral RNA levels in different organs did not correlate with the pathogenicity of the different strains. Taken together, we have established a new murine model that supports ZIKV infection and demonstrate its utility in highlighting intrinsic differences in the inflammatory response induced by different ZIKV strains leading to severity of disease. This study paves the way for the future interrogation of strain-specific changes in the ZIKV genome and their contribution to viral pathogenesis.

Effect of the South African asinine-94 strain of equine arteritis virus (EAV) in pregnant donkey mares and duration of maternal immunity in foals.

Science.gov (United States)

Paweska, J T

1997-06-01

Clinical, virological and serological responses were investigated in five pregnant donkey mares after experimental exposure to the South African asinine-94 strain of equine arteritis virus (EAV), and the duration of maternal immunity to EAV was studied in their foals. In four intranasally inoculated mares, fever with maximum rectal temperatures of 39.1-40.7 degrees C was recorded 2-11 d after challenge. All the inoculated mares developed mild depression, and a serous ocular and nasal discharge; in three mares mild conjuctivitis was observed. The virus was recovered from the nasopharynx and from buffy-coat samples of all the mares 3-10 d, and 2-18 d post inoculation (p.i.), respectively. Seroconversion to EAV was detected on days 8-10 p.i. Peak serum-virus-neutralizing antibody titres of log10 1.8-2.4, and IgG ELISA OD values of 0.85-2.15 were recorded 2-3 weeks p.i. The in-contact (p.c.) control mare developed fever on days 15-19 post exposure, and showed mild clinical signs of equine viral arteritis similar to those observed in the inoculated mares. Seroconversion to EAV was detected in the p.c. mare on day 20 post exposure, and virus was isolated from nasal swabs and blood samples collected at the time of the febrile response and 1-3 d afterwards. None of the mares aborted. After they had given normal birth 45-128 d p.i. or after p.c. exposure, no virus could be isolated from their placentas. The concentration of EAV-neutralizing antibody in colostrum was two to eight times higher than in serum samples collected at the time of parturition. All the foals born to infected mares were clinically normal at the time of birth and throughout the subsequent 1-2 months of observation. No EAV was recovered from the buffy-coat fraction of blood samples collected at birth nor from those collected on days 1, 2 and 7 after birth. Also, no virus-serum-neutralizing or IgG ELISA antibody to EAV was detected in sera collected immediately after birth before the foals started nursing

POST-TRAUMATIC AND POST-MODERN: A SOUTH AFRICAN “ELECTRA”

OpenAIRE

E. Steinmeyer

2012-01-01

The ancient myth of Electra seems to be of particular interest to South African writers and playwrights. This article focuses on the adaptation by Mervyn McMurtry, entitled Electra, which was produced in Durban in 2000. The underlying theme of his adaptation, which is based on the four Greek “Electra” tragedies by Aeschylus, Sophocles and Euripides, is the question of truth. This question — an important post-modern one — was of particular relevance for the Truth and Reconciliation Commission ...

FELINE IMMUNODEFICIENCY VIRUS (FIV) IN WILD PALLAS’ CATS

Science.gov (United States)

Brown, Meredith A.; Munkhtsog, Bariushaa; Troyer, Jennifer L.; Ross, Steve; Sellers, Rani; Fine, Amanda E.; Swanson, William F.; Roelke, Melody E.; O’Brien1, Stephen J.

2009-01-01

Feline immunodeficiency virus (FIV), a feline lentivirus related to HIV, causes immune dysfunction in domestic and wild cats. The Pallas’ cat is the only species from Asia known to harbor a species-specific strain of FIV designated FIVOma in natural populations. Here, a 25% seroprevalence of FIV is reported from 28 wild Mongolian Pallas’ cats sampled from 2000-2008. Phylogenetic analysis of proviral RT-Pol from eight FIVOma isolates from Mongolia, Russia, China and Kazakhstan reveals a unique monophyletic lineage of the virus within the Pallas’ cat population, most closely related to the African cheetah and leopard FIV strains. Histopathological examination of lymph node and spleen from infected and uninfected Pallas’ cats suggests that FIVOma causes immune depletion in its’ native host. PMID:19926144

Measles virus C protein suppresses gamma-activated factor formation and virus-induced cell growth arrest

International Nuclear Information System (INIS)

Yokota, Shin-ichi; Okabayashi, Tamaki; Fujii, Nobuhiro

2011-01-01

Measles virus (MeV) produces two accessory proteins, V and C, from the P gene. These accessory proteins have been reported to contribute to efficient virus proliferation through the modulation of host cell events. Our previous paper described that Vero cell-adapted strains of MeV led host cells to growth arrest through the upregulation of interferon regulatory factor 1 (IRF-1), and wild strains did not. In the present study, we found that C protein expression levels varied among MeV strains in infected SiHa cells. C protein levels were inversely correlated with IRF-1 expression levels and with cell growth arrest. Forced expression of C protein released cells from growth arrest. C-deficient recombinant virus efficiently upregulated IRF-1 and caused growth arrest more efficiently than the wild-type virus. C protein preferentially bound to phosphorylated STAT1 and suppressed STAT1 dimer formation. We conclude that MeV C protein suppresses IFN-γ signaling pathway via inhibition of phosphorylated STAT1 dimerization.

Genotypic and phenotypic characterization of Chikungunya virus of different genotypes from Malaysia.

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I-Ching Sam

Full Text Available BACKGROUND: Mosquito-borne Chikungunya virus (CHIKV has recently re-emerged globally. The epidemic East/Central/South African (ECSA strains have spread for the first time to Asia, which previously only had endemic Asian strains. In Malaysia, the ECSA strain caused an extensive nationwide outbreak in 2008, while the Asian strains only caused limited outbreaks prior to this. To gain insight into these observed epidemiological differences, we compared genotypic and phenotypic characteristics of CHIKV of Asian and ECSA genotypes isolated in Malaysia. METHODS AND FINDINGS: CHIKV of Asian and ECSA genotypes were isolated from patients during outbreaks in Bagan Panchor in 2006, and Johor in 2008. Sequencing of the CHIKV strains revealed 96.8% amino acid similarity, including an unusual 7 residue deletion in the nsP3 protein of the Asian strain. CHIKV replication in cells and Aedes mosquitoes was measured by virus titration. There were no differences in mammalian cell lines. The ECSA strain reached significantly higher titres in Ae. albopictus cells (C6/36. Both CHIKV strains infected Ae. albopictus mosquitoes at a higher rate than Ae. aegypti, but when compared to each other, the ECSA strain had much higher midgut infection and replication, and salivary gland dissemination, while the Asian strain infected Ae. aegypti at higher rates. CONCLUSIONS: The greater ability of the ECSA strain to replicate in Ae. albopictus may explain why it spread far more quickly and extensively in humans in Malaysia than the Asian strain ever did, particularly in rural areas where Ae. albopictus predominates. Intergenotypic genetic differences were found at E1, E2, and nsP3 sites previously reported to be determinants of host adaptability in alphaviruses. Transmission of CHIKV in humans is influenced by virus strain and vector species, which has implications for regions with more than one circulating CHIKV genotype and Aedes species.

Expression of DAI by an oncolytic vaccinia virus boosts the immunogenicity of the virus and enhances antitumor immunity

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Mari Hirvinen

2016-01-01

Full Text Available In oncolytic virotherapy, the ability of the virus to activate the immune system is a key attribute with regard to long-term antitumor effects. Vaccinia viruses bear one of the strongest oncolytic activities among all oncolytic viruses. However, its capacity for stimulation of antitumor immunity is not optimal, mainly due to its immunosuppressive nature. To overcome this problem, we developed an oncolytic VV that expresses intracellular pattern recognition receptor DNA-dependent activator of IFN-regulatory factors (DAI to boost the innate immune system and to activate adaptive immune cells in the tumor. We showed that infection with DAI-expressing VV increases expression of several genes related to important immunological pathways. Treatment with DAI-armed VV resulted in significant reduction in the size of syngeneic melanoma tumors in mice. When the mice were rechallenged with the same tumor, DAI-VV-treated mice completely rejected growth of the new tumor, which indicates immunity established against the tumor. We also showed enhanced control of growth of human melanoma tumors and elevated levels of human T-cells in DAI-VV-treated mice humanized with human peripheral blood mononuclear cells. We conclude that expression of DAI by an oncolytic VV is a promising way to amplify the vaccine potency of an oncolytic vaccinia virus to trigger the innate—and eventually the long-lasting adaptive immunity against cancer.

[Microbiological surveillance: viral hemorrhagic fever in Central African Republic: current serological data in man].

Science.gov (United States)

Nakounné, E; Selekon, B; Morvan, J

2000-01-01

An investigation was conducted between 1994 and 1997 in forested areas of the Central African Republic (CAR) to determine the seroprevalence of IgG antibodies against several haemorrhagic fever viruses present in the region. Sera were obtained from 1762 individuals in two groups (Pygmy and Bantu locuted populations) living in 4 forested areas in the south of the country. Sera were tested for IgG antibodies against Ebola, Marburg, Rift Valley fever (RVF), Yellow fever (YF) and Hantaviruses by enzyme immunoassay (EIA), and against Lassa virus by immunofluorescent assay. The prevalence of IgG antibodies was 5.9% for Ebola, 2% for Marburg, 6.9% pour RVF, 6.5% for YF, 2% for Hantaan. No antibodies were detected against Lassa, Seoul, Puumala and Thottapalayam viruses. No IgM antibodies were detected against RVF and YF viruses. The distribution of antibodies appears to be related to tropical rain forest areas. This study indicates that several haemorrhagic fever viruses are endemic in forested areas of the CAR and could emerge due to environmental modification.

DNA-Binding Properties of African Swine Fever Virus pA104R, a Histone-Like Protein Involved in Viral Replication and Transcription.

Science.gov (United States)

Frouco, Gonçalo; Freitas, Ferdinando B; Coelho, João; Leitão, Alexandre; Martins, Carlos; Ferreira, Fernando

2017-06-15

African swine fever virus (ASFV) codes for a putative histone-like protein (pA104R) with extensive sequence homology to bacterial proteins that are implicated in genome replication and packaging. Functional characterization of purified recombinant pA104R revealed that it binds to single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA) over a wide range of temperatures, pH values, and salt concentrations and in an ATP-independent manner, with an estimated binding site size of about 14 to 16 nucleotides. Using site-directed mutagenesis, the arginine located in pA104R's DNA-binding domain, at position 69, was found to be relevant for efficient DNA-binding activity. Together, pA104R and ASFV topoisomerase II (pP1192R) display DNA-supercoiling activity, although none of the proteins by themselves do, indicating that the two cooperate in this process. In ASFV-infected cells, A104R transcripts were detected from 2 h postinfection (hpi) onward, reaching a maximum concentration around 16 hpi. pA104R was detected from 12 hpi onward, localizing with viral DNA replication sites and being found exclusively in the Triton-insoluble fraction. Small interfering RNA (siRNA) knockdown experiments revealed that pA104R plays a critical role in viral DNA replication and gene expression, with transfected cells showing lower viral progeny numbers (up to a reduction of 82.0%), lower copy numbers of viral genomes (-78.3%), and reduced transcription of a late viral gene (-47.6%). Taken together, our results strongly suggest that pA104R participates in the modulation of viral DNA topology, probably being involved in viral DNA replication, transcription, and packaging, emphasizing that ASFV mutants lacking the A104R gene could be used as a strategy to develop a vaccine against ASFV. IMPORTANCE Recently reintroduced in Europe, African swine fever virus (ASFV) causes a fatal disease in domestic pigs, causing high economic losses in affected countries, as no vaccine or treatment is currently

Hepatitis A virus: a test method for virucidal activity.

Science.gov (United States)

Wolff, M H; Schmitt, J; Rahaus, M; König, A

2001-08-01

Hepatitis A virus (HAV) is closely related to the genus enterovirus. HAV is very stable and resistant to acid pH and elevated temperature, as well as to chemicals and environmental influences. Human poliovirus is still one of the model viruses for testing disinfectants but there are discussions about changing to hepatitis A virus. The purpose of this study was to develop a method for using adapted hepatitis A virus to test hand disinfectants. Using HAV strains HM175/24a and FRhK-4 cytopathic effects were visible rarely, and not before 14 days. To verify virus growth in cells a RT-PCR was developed. Two disinfectants tested did not show the required virucidal activity to satisfy current German guidelines.

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

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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.

Preparing for Ebola Virus Disease in West African countries not yet affected: perspectives from Ghanaian health professionals.

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Nyarko, Yaw; Goldfrank, Lewis; Ogedegbe, Gbenga; Soghoian, Sari; de-Graft Aikins, Ama

2015-02-26

The current Ebola Virus Disease (EVD) epidemic has ravaged the social fabric of three West African countries and affected people worldwide. We report key themes from an agenda-setting, multi-disciplinary roundtable convened to examine experiences and implications for health systems in Ghana, a nation without cases but where risk for spread is high and the economic, social and political impact of the impending threat is already felt. Participants' personal stories and the broader debates to define fundamental issues and opportunities for preparedness focused on three inter-related themes. First, the dangers of the fear response itself were highlighted as a threat to the integrity and continuity of quality care. Second, healthcare workers' fears were compounded by a demonstrable lack of societal and personal protections for infection prevention and control in communities and healthcare facilities, as evidenced by an ongoing cholera epidemic affecting over 20,000 patients in the capital Accra alone since June 2014. Third, a lack of coherent messaging and direction from leadership seems to have limited coordination and reinforced a level of mistrust in the government's ability and commitment to mobilize an adequate response. Initial recommendations include urgent investment in the needed supplies and infrastructure for basic, routine infection control in communities and healthcare facilities, provision of assurances with securities for frontline healthcare workers, establishment of a multi-sector, "all-hazards" outbreak surveillance system, and engaging directly with key community groups to co-produce contextually relevant educational messages that will help decrease stigma, fear, and the demoralizing perception that the disease defies remedy or control. The EVD epidemic provides an unprecedented opportunity for West African countries not yet affected by EVD cases to make progress on tackling long-standing health systems weaknesses. This roundtable discussion

Counting the cost of Afrophobia: Post-migration adaptation and mental health challenges of African refugees in South Africa.

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Thela, Lindokuhle; Tomita, Andrew; Maharaj, Varsha; Mhlongo, Mpho; Burns, Jonathan K

2017-01-01

There are few studies on the role of migration within sub-Saharan Africa and its relation to the development of mental illness. We investigated post-resettlement adaptation and mental health challenges of African refugees/migrants in Durban, South Africa. We interviewed 335 African help-seeking refugees/migrants for anxiety, depression (25-item Hopkins Symptom Checklist) and post-traumatic stress symptoms (30-item Harvard Trauma Questionnaire). Socio-demographic and migration history, focusing on post-migration circumstances and experiences of discrimination in the host country, were obtained. Association between migration and post-settlement factors and mental health outcomes were assessed using adjusted logistic regression models. Prevalence of mental distress was high: 49.4% anxiety, 54.6% depression and 24.9% post-traumatic stress symptoms. After adjustment for family separation since migration, recent arrival in South Africa was associated with increased risk for depression (aOR = 4.0, 95% CI:1.3-11.8) and post-traumatic stress (aOR = 5.2, 95% CI:1.7-15.9), while in unadjusted models, older age on arrival was associated with anxiety (aOR = 5.3, 95% CI:1.4-19.8) and depression (aOR = 6.2, 95% CI:1.6-24.3). History of family separation since migration was independently associated with depression and post-traumatic stress in all models. Discriminatory experiences since migration was also an independent risk factor for all three mental health outcomes. Finally, being divorced/widowed was associated with an increased risk for post-traumatic stress, while higher income earners were protected against post-traumatic symptoms, even after adjustment. Refugees/migrants in South Africa show a significant burden of mental distress that is linked to challenges of adjustment in an often hostile context. Services addressing these and other health-related, social-economic needs should be developed as a priority.

Parsing the Gulf between Africans and African Americans

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Ashly Nsangou

2018-02-01

Full Text Available The rise in African immigrants to the US provides an opportunity to assess relations between Africans and African Americans in college. An online survey of 322 current and recently-graduated college students (including 45 Africans, 160 African Americans, and 117 whites assessed respondents’ experiences of racism in US high schools and colleges. Semi-structured interviews of 30 students (10 African, 10 African American and 10 white students supplemented these data. Even within a sociopolitical context of more visible racial intolerance, Black intra-racial cohesion was absent. Although more first- and second-generation Africans (73% felt that they had been judged while living in the US compared to African Americans (34% or whites (20%, for 70–80% of respondents, this had occurred only in high school. Despite experiencing these judgments, Africans’ identity related more to their focus on education than their race, reflected in a higher proportion who felt intense family pressure to attend college (65% compared to African Americans (37% and whites (39%. Interview data confirmed previous reports in the literature that African Americans lack a sense of connection to Africans, attributed to Africans’ purported sense of superiority and disregard for African Americans’ ongoing struggle to end oppression. These mixed-methods data suggest that intermingling in the college environment has not resulted in first- and second-generation Africans and African Americans sharing a common in-group, race-based identity. We discuss the implications of overlooking ethnic distinctions due to presumptions of racial homogeneity that deprive Black individuals of their uniqueness.

Dengue virus type 3 adaptive changes during epidemics in São 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.