Salama, S.A.; Dardiri, A. H.; Awad, F. I.; A. M. Soliman; M.M Amin
African horsesickness virus was isolated from blood samples of street dogs in Aswan Province in Arab Republic of Egypt. Of six isolated "dog strain" African horsesickness viruses, three viruses designated D2, D6 and D10 have been identified as type 9 African horsesickness virus. Methods of isolation, tissue culture adaptation, serological indentification and typing are described. Horses experimentally infected with dog viruses showed febrile reaction and characteristic clinical and pathologic...
Potgieter, A. Christiaan; Wright, Isabella M.; van Dijk, Alberdina A.
We announce the complete consensus genome sequence of 27 African horse sickness viruses, representing all nine African horse sickness virus (AHSV) serotypes from historical and recent isolates collected over a 76-year period (1933 to 2009). The data set includes the sequence of the virulent Office International des Epizooties AHSV reference strains which are not adapted to cell culture.
Foot-and-mouth disease virus (FMDV) attains entry to epithelial cells by affinity for at least four members of the integrin family of receptors. Adaptation of field isolates to grow in cultured cells is an essential step towards development of vaccines against new outbreak strains. This is made poss...
Desdouits, Marion; Kamgang, Basile; Berthet, Nicolas; Tricou, Vianney; Ngoagouni, Carine; Gessain, Antoine; Manuguerra, Jean-Claude; Nakouné, Emmanuel; Kazanji, Mirdad
Chikungunya virus (CHIKV) is an alphavirus transmitted by the bite of mosquito vectors. Over the past 10 years, the virus has gained mutations that enhance its transmissibility by the Aedes albopictus vector, resulting in massive outbreaks in the Indian Ocean, Asia and Central Africa. Recent introduction of competent A. albopictus vectors into the Central African Republic (CAR) pose a threat of a Chikungunya fever (CHIKF) epidemic in this region. We undertook this study to assess the genetic diversity and background of CHIKV strains isolated in the CAR between 1975 and 1984 and also to estimate the ability of local strains to adapt to A. albopictus. Our results suggest that, local CHIKV strains have a genetic background compatible with quick adaptation to A. albopictus, as previously observed in other Central African countries. Intense surveillance of the human and vector populations is necessary to prevent or anticipate the emergence of a massive CHIKF epidemic in the CAR.
Cardoso de Carvalho Ferreira, H.
African swine fever is a haemorrhagic disease of swine caused by African swine fever virus (ASFV). Estimates of virus transmission (direct or indirect) parameters for ASFV are necessary in order to model the spread of the virus, and to design more efficient control measures. Results presented on thi
Carvalho Ferreira, de H.C.; Weesendorp, E.; Quak, S.; Stegeman, J.A.; Loeffen, W.L.A.
Knowledge on African Swine Fever (ASF) transmission routes can be useful when designing control measures against the spread of ASF virus (ASFV). Few studies have focused on the airborne transmission route, and until now no data has been available on quantities of ASF virus (ASFV) in the air. Our aim
Brawand, David; Russell, Pamela
Cichlid fishes are famous for large, diverse and replicated adaptive radiations in the Great Lakes of East Africa. To understand the molecular mechanisms underlying cichlid phenotypic diversity, we sequenced the genomes and transcriptomes of five lineages of African cichlids: the Nile tilapia (Oreochromis niloticus), an ancestral lineage with low diversity; and four members of the East African lineage: Neolamprologus brichardi/pulcher (older radiation, Lake Tanganyika), Metriaclima zebra (rec...
Jana Verena Roedig
Full Text Available The genome of influenza A viruses is constantly changing (genetic drift resulting in small, gradual changes in viral proteins. Alterations within antibody recognition sites of the viral membrane glycoproteins hemagglutinin (HA and neuraminidase (NA result in an antigenetic drift, which requires the seasonal update of human influenza virus vaccines. Generally, virus adaptation is necessary to obtain sufficiently high virus yields in cell culture-derived vaccine manufacturing. In this study detailed HA N-glycosylation pattern analysis was combined with in-depth pyrosequencing analysis of the virus genomic RNA. Forward and backward adaptation from Madin-Darby Canine Kidney (MDCK cells to African green monkey kidney (Vero cells was investigated for two closely related influenza A virus PR/8/34 (H1N1 strains: from the National Institute for Biological Standards and Control (NIBSC or the Robert Koch Institute (RKI. Furthermore, stability of HA N-glycosylation patterns over ten consecutive passages and different harvest time points is demonstrated. Adaptation to Vero cells finally allowed efficient influenza A virus replication in Vero cells. In contrast, during back-adaptation the virus replicated well from the very beginning. HA N-glycosylation patterns were cell line dependent and stabilized fast within one (NIBSC-derived virus or two (RKI-derived virus successive passages during adaptation processes. However, during adaptation new virus variants were detected. These variants carried "rescue" mutations on the genomic level within the HA stem region, which result in amino acid substitutions. These substitutions finally allowed sufficient virus replication in the new host system. According to adaptation pressure the composition of the virus populations varied. In Vero cells a selection for "rescue" variants was characteristic. After back-adaptation to MDCK cells some variants persisted at indifferent frequencies, others slowly diminished and even
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.
Rijn, van Piet A.; Water, van de Sandra G.P.; Feenstra, Femke; Gennip, van René G.P.
Background: Bluetongue virus (BTV) and African horse sickness virus (AHSV) are distinct arthropod borne virus species in the genus Orbivirus (Reoviridae family), causing the notifiable diseases Bluetongue and African horse sickness of ruminants and equids, respectively. Reverse genetics systems f
Oluwafemi, Sunday; Varsani, Arvind; Monjane, Adérito L; Shepherd, Dionne N; Owor, Betty E; Rybicki, Edward P; Martin, Darren P
The African streak viruses (AfSVs) are a diverse group of mastrevirus species (family Geminiviridae) that infect a wide variety of annual and perennial grass species across the African continent and its nearby Indian Ocean islands. Six AfSV species (of which maize streak virus is the best known) have been described. Here we report the full genome sequences of eight isolates of a seventh AfSV species: Urochloa streak virus (USV), sampled from various locations in Nigeria. Despite there being good evidence of recombination in many other AfSV species, we found no convincing evidence that any of the USV sequences were either inter- or intra-species recombinants. The USV isolates, all of which appear to be variants of the same strain (their genome sequences are all more than 98% identical), share less than 69% nucleotide sequence identity with other currently described AfSV species. PMID:18521534
Anchuelo, Raquel; Pelayo, Virginia; Poudevigne, Frédéric; Leon, Tati; Nzoussi, Jacques; Bishop, Richard; Pérez, Covadonga; Soler, Alejandro; Nieto, Raquel; Martín, Hilario; Arias, Marisa
African swine fever virus p72 genotype IX, associated with outbreaks in eastern Africa, is cocirculating in the Republic of the Congo with West African genotype I. Data suggest that viruses from eastern Africa are moving into western Africa, increasing the threat of outbreaks caused by novel viruses in this region. PMID:21801650
Carvalho Ferreira, de H.C.; Zúquete, S.T.; Wijnveld, M.; Weesendorp, E.; Jongejan, F.; Stegeman, J.A.; Loeffen, W.L.A.
African swine fever (ASF) is caused by African swine fever virus (ASFV), a tick-borne DNA virus. Soft ticks of the genus Ornithodoros are the only biological vectors of ASFV recognized so far. Although other hard ticks have been tested for vector competence, two commonly found tick species in Europe
Full Text Available BACKGROUND: The haplochromine cichlid species assemblages of Lake Malawi and Victoria represent some of the most important study systems in evolutionary biology. Identifying adaptive divergence between closely-related species can provide important insights into the processes that may have contributed to these spectacular radiations. Here, we studied a pair of sympatric Lake Malawi species, Pseudotropheus fainzilberi and P. emmiltos, whose reproductive isolation depends on olfactory communication. We tested the hypothesis that these species have undergone divergent selection at MHC class II genes, which are known to contribute to olfactory-based mate choice in other taxa. METHODOLOGY/PRINCIPAL FINDINGS: Divergent selection on functional alleles was inferred from the higher genetic divergence at putative antigen binding sites (ABS amino acid sequences than at putatively neutrally evolving sites at intron 1, exon 2 synonymous sequences and exon 2 amino acid residues outside the putative ABS. In addition, sympatric populations of these fish species differed significantly in communities of eukaryotic parasites. CONCLUSIONS/SIGNIFICANCE: We propose that local host-parasite coevolutionary dynamics may have driven adaptive divergence in MHC alleles, influencing odor-mediated mate choice and leading to reproductive isolation. These results provide the first evidence for a novel mechanism of adaptive speciation and the first evidence of adaptive divergence at the MHC in closely related African cichlid fishes.
Maree, Sonja; Maree, Francois F; Putterill, John F; de Beer, Tjaart A P; Huismans, Henk; Theron, Jacques
As a means to develop African horse sickness (AHS) vaccines that are safe and DIVA compliant, we investigated the synthesis of empty African horse sickness virus (AHSV) particles. The emphasis of this study was on the assembly of the major viral core (VP3 and VP7) and outer capsid proteins (VP2 and VP5) into architecturally complex, heteromultimeric nanosized particles. The production of fully assembled core-like particles (CLPs) was accomplished in vivo by baculovirus-mediated co-synthesis of VP3 and VP7. The two different outer capsid proteins were capable of associating independently of each other with preformed cores to yield partial virus-like particles (VLPs). Complete VLPs were synthesized, albeit with a low yield. Crystalline formation of AHSV VP7 trimers is thought to impede high-level CLP production. Consequently, we engineered and co-synthesized VP3 with a more hydrophilic mutant VP7, resulting in an increase in the turnover of CLPs. PMID:26686484
Marah, John Karefah
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…
Brittain, Kelly; Taylor, Jacquelyn Y.; Wu, Chun Yi
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...
E.J.A. Schrauwen (Eefje); R.A.M. Fouchier (Ron)
textabstractA 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 infection
Cooley, Eileen L.; Garcia, Amber L.
This study examined ethnic differences in attachment styles and depression among African American and European American college women. African American women reported less favorable views of others, which suggests that attachment styles emphasizing caution in relationships may be normative and adaptive for these women. There were no differences…
N'Dindin, A C; Djeredou, K B; N'Dindin-Guinan, B; Assi, K D
Articulators and facial arc always used in dentistry are not adapted to African black people. Their use provokes many errors in the setting of models on articulators. In this work, authors propose facial arc and articulator parameters conceptions that are suited to black Africans.
Naseem, Saadia; Winter, Stephan
The quantity of genomic DNA-A and DNA-B of African cassava mosaic virus (ACMV) and East African cassava mosaic virus Uganda (Uganda variant, EACMV-UG) was analysed using quantitative PCR to assess virus concentrations in plants from susceptible and tolerant cultivars. The concentrations of genome components in absolute and relative quantification experiments in single and mixed viral infections were determined. Virus concentration was much higher in symptomatic leaf tissues compared to non-symptomatic leaves and corresponded with the severity of disease symptoms. In general, higher titres were recorded for EACMV-UG Ca055 compared to ACMV DRC6. The quantitative assessment also showed that the distribution of both viruses in the moderately resistant cassava cv. TMS 30572 was not different from the highly susceptible cv. TME 117. Natural mixed infections with both viruses gave severe disease symptoms. Relative quantification of virus genomes in mixed infections showed higher concentrations of EACMV-UG DNA-A compared to ACMV DNA-A, but a marked reduction of EACMV-UG DNA-B. The higher concentrations of EACMV-UG DNA-B compared to EACMV DNA-A accumulation in single infections were consistent. Since DNA-B is implicated in virus cell-to-cell spread and systemic movement, the abundance of the EACMV-UG DNA-B may be an important factor driving cassava mosaic disease epidemic.
Antonio V Bordería
Full Text Available Understanding how a pathogen colonizes and adapts to a new host environment is a primary aim in studying emerging infectious diseases. Adaptive mutations arise among the thousands of variants generated during RNA virus infection, and identifying these variants will shed light onto how changes in tropism and species jumps can occur. Here, we adapted Coxsackie virus B3 to a highly permissive and less permissive environment. Using deep sequencing and bioinformatics, we identified a multi-step adaptive process to adaptation involving residues in the receptor footprints that correlated with receptor availability and with increase in virus fitness in an environment-specific manner. We show that adaptation occurs by selection of a dominant mutation followed by group selection of minority variants that together, confer the fitness increase observed in the population, rather than selection of a single dominant genotype.
Full Text Available The majority of recently emerging infectious diseases in humans is due to cross-species pathogen transmissions from animals. To establish a productive infection in new host species, viruses must overcome barriers to replication mediated by diverse and rapidly evolving host restriction factors such as protein kinase R (PKR. Many viral antagonists of these restriction factors are species specific. For example, the rhesus cytomegalovirus PKR antagonist, RhTRS1, inhibits PKR in some African green monkey (AGM cells, but does not inhibit human or rhesus macaque PKR. To model the evolutionary changes necessary for cross-species transmission, we generated a recombinant vaccinia virus that expresses RhTRS1 in a strain that lacks PKR inhibitors E3L and K3L (VVΔEΔK+RhTRS1. Serially passaging VVΔEΔK+RhTRS1 in minimally-permissive AGM cells increased viral replication 10- to 100-fold. Notably, adaptation in these AGM cells also improved virus replication 1000- to 10,000-fold in human and rhesus cells. Genetic analyses including deep sequencing revealed amplification of the rhtrs1 locus in the adapted viruses. Supplying additional rhtrs1 in trans confirmed that amplification alone was sufficient to improve VVΔEΔK+RhTRS1 replication. Viruses with amplified rhtrs1 completely blocked AGM PKR, but only partially blocked human PKR, consistent with the replication properties of these viruses in AGM and human cells. Finally, in contrast to AGM-adapted viruses, which could be serially propagated in human cells, VVΔEΔK+RhTRS1 yielded no progeny virus after only three passages in human cells. Thus, rhtrs1 amplification in a minimally permissive intermediate host was a necessary step, enabling expansion of the virus range to previously nonpermissive hosts. These data support the hypothesis that amplification of a weak viral antagonist may be a general evolutionary mechanism to permit replication in otherwise resistant host species, providing a molecular foothold
Snoeck Chantal J
Full Text Available Abstract Background Although chicken anemia virus (CAV has been detected on all continents, little is known about this virus in sub-Saharan Africa. This study aimed to detect and characterize CAV for the first time in Central African Republic and in Cameroon. Results An overall flock seroprevalence of 36.7% was found in Central African Republic during the 2008–2010 period. Virus prevalences were 34.2% (2008, 14.3% (2009 and 10.4% (2010 in Central African Republic and 39% (2007 and 34.9% (2009 in Cameroon. CAV DNA was found in cloacal swabs of 76.9% of seropositive chickens, suggesting that these animals excreted the virus despite antibodies. On the basis of VP1 sequences, most of the strains in Central African Republic and Cameroon belonged to 9 distinct phylogenetic clusters at the nucleotide level and were not intermixed with strains from other continent. Several cases of mixed infections in flocks and individual chickens were identified. Conclusions Our results suggest multiple introductions of CAV in each country that later spread and diverged locally. Mixed genotype infections together with the observation of CAV DNA in cloacal samples despite antibodies suggest a suboptimal protection by antibodies or virus persistence.
Katoh, Hiroshi; Kubota, Toru; Ihara, Toshiaki; Maeda, Ken; Takeda, Makoto; Kidokoro, Minoru
Recently, a new paramyxovirus closely related to human mumps virus (MuV) was detected in bats. We generated recombinant MuVs carrying either or both of the fusion and hemagglutinin-neuraminidase bat virus glycoproteins. These viruses showed replication kinetics similar to human MuV in cultured cells and were neutralized efficiently by serum from healthy humans. PMID:26982800
Tun, Mya Myat Ngwe; Thant, Kyaw Zin; Inoue, Shingo; Nabeshima, Takeshi; Aoki, Kotaro; Kyaw, Aung Kyaw; Myint, Tin; Tar, Thi; Maung, Kay Thwe Thwe; Hayasaka, Daisuke; Morita, Kouichi
In 2010, chikungunya virus of the East Central South African genotype was isolated from 4 children in Myanmyar who had dengue-like symptoms. Phylogenetic analysis of the E1 gene revealed that the isolates were closely related to isolates from China, Thailand, and Malaysia that harbor the A226V mutation in this gene.
Carvalho Ferreira, de H.C.; Weesendorp, E.; Elbers, A.R.W.; Bouma, A.; Quak, S.; Stegeman, J.A.; Loeffen, W.L.A.
The continuing circulation of African swine fever (ASF) in Russia and in the Trans-Caucasian countries has led to increased efforts in characterizing the epidemiology of ASF. For a better insight in epidemiology, quantitative data on virus excretion is required. Until now, excretion data has mainly
Tun, Mya Myat Ngwe; Thant, Kyaw Zin; Inoue, Shingo; Nabeshima, Takeshi; Aoki, Kotaro; Kyaw, Aung Kyaw; Myint, Tin; Tar, Thi; Maung, Kay Thwe Thwe; Hayasaka, Daisuke; Morita, Kouichi
In 2010, chikungunya virus of the East Central South African genotype was isolated from 4 children in Myanmyar who had dengue-like symptoms. Phylogenetic analysis of the E1 gene revealed that the isolates were closely related to isolates from China, Thailand, and Malaysia that harbor the A226V mutation in this gene.
Gededzha, Maemu P; Muzeze, Muxe; Burnett, Rosemary J; Amponsah-Dacosta, Edina; Mphahlele, M Jeffrey; Selabe, Selokela G
Hepatitis B virus (HBV) and human immunodeficiency virus (HIV) infections are highly endemic in South Africa. Data on the complete genome sequences of HBV in HIV-positive patients in South Africa are scanty. This study characterized the complete HBV genome isolated from both HIV-positive and negative patients at the Dr George Mukhari Academic Hospital (DGMAH), Pretoria. Serum samples from nine (five HIV-positive and four HIV-negative) patients attending the DGMAH from 2007 to 2011 were serologically tested, amplified, and sequenced for complete genome. Phylogenetic tree was constructed using MEGA6.0. Mutations were analyzed by comparing the sequences with genotype-matched GenBank references. Eight patients were HBsAg positive, with only one from the HIV positive group being negative. Phylogenetic analysis of the complete genome sequences classified them into five genotypes; A1 (n = 4), A2 (n = 1), C1 (n = 2), D1 (n = 1), and D3 (n = 1). Deletions up to 35 nucleotides in length were identified in this study. No drug resistance mutations were identified in the P ORF, while the L217R mutation was identified in one subgenotype A2 sequence. The double (A1762T/G1764A) and triple (T1753C/A1762T/G1764A) mutations in the Basal core promoter were identified in four and two sequences, respectively. In the core region, mutation G1888A was identified in four of the subgenotype A1 sequences. In conclusion, this study has added to the limited South African data on HBV genotypes and mutations in HBV/HIV co-infected and HBV mono-infected patients, based on complete HBV genome analysis. Subgenotype A1 was predominant, and no drug-resistant mutants were detected in the study. J. Med. Virol. 88:1560-1566, 2016. © 2016 Wiley Periodicals, Inc. PMID:26890489
Gededzha, Maemu P; Muzeze, Muxe; Burnett, Rosemary J; Amponsah-Dacosta, Edina; Mphahlele, M Jeffrey; Selabe, Selokela G
Hepatitis B virus (HBV) and human immunodeficiency virus (HIV) infections are highly endemic in South Africa. Data on the complete genome sequences of HBV in HIV-positive patients in South Africa are scanty. This study characterized the complete HBV genome isolated from both HIV-positive and negative patients at the Dr George Mukhari Academic Hospital (DGMAH), Pretoria. Serum samples from nine (five HIV-positive and four HIV-negative) patients attending the DGMAH from 2007 to 2011 were serologically tested, amplified, and sequenced for complete genome. Phylogenetic tree was constructed using MEGA6.0. Mutations were analyzed by comparing the sequences with genotype-matched GenBank references. Eight patients were HBsAg positive, with only one from the HIV positive group being negative. Phylogenetic analysis of the complete genome sequences classified them into five genotypes; A1 (n = 4), A2 (n = 1), C1 (n = 2), D1 (n = 1), and D3 (n = 1). Deletions up to 35 nucleotides in length were identified in this study. No drug resistance mutations were identified in the P ORF, while the L217R mutation was identified in one subgenotype A2 sequence. The double (A1762T/G1764A) and triple (T1753C/A1762T/G1764A) mutations in the Basal core promoter were identified in four and two sequences, respectively. In the core region, mutation G1888A was identified in four of the subgenotype A1 sequences. In conclusion, this study has added to the limited South African data on HBV genotypes and mutations in HBV/HIV co-infected and HBV mono-infected patients, based on complete HBV genome analysis. Subgenotype A1 was predominant, and no drug-resistant mutants were detected in the study. J. Med. Virol. 88:1560-1566, 2016. © 2016 Wiley Periodicals, Inc.
Jonathan S Towner
Full Text Available Marburg and Ebola viruses can cause large hemorrhagic fever (HF outbreaks with high case fatality (80-90% in human and great apes. Identification of the natural reservoir of these viruses is one of the most important topics in this field and a fundamental key to understanding their natural history. Despite the discovery of this virus family almost 40 years ago, the search for the natural reservoir of these lethal pathogens remains an enigma despite numerous ecological studies. Here, we report the discovery of Marburg virus in a common species of fruit bat (Rousettus aegyptiacus in Gabon as shown by finding virus-specific RNA and IgG antibody in individual bats. These Marburg virus positive bats represent the first naturally infected non-primate animals identified. Furthermore, this is the first report of Marburg virus being present in this area of Africa, thus extending the known range of the virus. These data imply that more areas are at risk for MHF outbreaks than previously realized and correspond well with a recently published report in which three species of fruit bats were demonstrated to be likely reservoirs for Ebola virus.
Lofton, Saria; Julion, Wrenetha A.; McNaughton, Diane B.; Bergren, Martha Dewey; Keim, Kathryn S.
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…
Lamglait, Benjamin; Joris, Antoine; Romey, Aurore; Bakkali-Kassimi, Labib; Lemberger, Karin
A fatal case of encephalomyocarditis virus (EMCV) involving an African elephant ( Loxodonta africana ) occurred in November 2013 at the Réserve Africaine de Sigean, France. An adult female was found dead without any preliminary symptoms. Gross pathologic changes consisted of petechiae and hemorrhages on mucosae and internal organs, abundant transudate in the abdominal and pericardial cavities, and myocarditis. Histopathologic examination showed extensive degeneration and necrosis of ventricular cardiomyocytes with concurrent lymphoplasmocytic and eosinophilic infiltrate. An EMCV was isolated from several organs and considered the causative agent of the myocarditis. The same strain of virus was also isolated in rodents captured on zoo premises and considered to be the reservoir of the virus. To the authors' knowledge, this is the first EMCV case in a captive African elephant in Europe.
Full Text Available Gene order is often highly conserved within taxonomic groups, such that organisms with rearranged genomes tend to be less fit than wildtype gene orders, and suggesting natural selection favors genome architectures that maximize fitness. But it is unclear whether rearranged genomes hinder adaptability: capacity to evolutionarily improve in a new environment. Negative-sense nonsegmented RNA viruses (order Mononegavirales have specific genome architecture: 3′ UTR – core protein genes – envelope protein genes – RNA-dependent RNA-polymerase gene – 5′ UTR. To test how genome architecture affects RNA virus evolution, we examined vesicular stomatitis virus (VSV variants with the nucleocapsid (N gene moved sequentially downstream in the genome. Because RNA polymerase stuttering in VSV replication causes greater mRNA production in upstream genes, N-gene translocation towards the 5’ end leads to stepwise decreases in N transcription, viral replication and progeny production, and also impacts the activation of type 1 interferon mediated antiviral responses. We evolved VSV gene-order variants in two prostate cancer cell lines: LNCap cells deficient in innate immune response to viral infection, and PC3 cells that mount an IFN stimulated anti-viral response to infection. We observed that gene order affects phenotypic adaptability (reproductive growth; viral suppression of immune function, especially on PC3 cells that strongly select against virus infection. Overall, populations derived from the least-fit ancestor (most-altered N position architecture adapted fastest, consistent with theory predicting populations with low initial fitness should improve faster in evolutionary time. Also, we observed correlated responses to selection, where viruses improved across both hosts, rather than suffer fitness trade-offs on unselected hosts. Whole genomics revealed multiple mutations in evolved variants, some of which were conserved across selective
The origin of new and complex structures and functions is fundamental for shaping the diversity of life. Such key innovations are rare because they require multiple interacting changes. We sought to understand how the adaptive landscape led to an innovation whereby bacteriophage λ evolved the new ability to exploit a receptor, OmpF, on Escherichia coli cells. Previous work showed that this ability evolved repeatedly, despite requiring four mutations in one virus gene. Here, we examine how this innovation evolved by studying six intermediate genotypes of λ isolated during independent transitions to exploit OmpF and comparing them to their ancestor. All six intermediates showed large increases in their adsorption rates on the ancestral host. Improvements in adsorption were offset, in large part, by the evolution of host resistance, which occurred by reduced expression of LamB, the usual receptor for λ. As a consequence of host coevolution, the adaptive landscape of the virus changed such that selection favouring four of the six virus intermediates became stronger after the host evolved resistance, thereby accelerating virus populations along the path to using the new OmpF receptor. This dependency of viral fitness on host genotype thus shows an important role for coevolution in the origin of the new viral function. PMID:27683370
Engel, M.; Essop, M; Close, P; Hartley, P.; Pallesen, G; Sinclair-Smith, C
Aim—To study the distribution of Hodgkin's lymphoma in South African children and report the incidence of Epstein-Barr virus (EBV) as regards age, race, sex, and histological subtype; to investigate whether EBV is relevant to survival.
The seasonal human influenza A virus undergoes rapid genome evolution. This process is triggered by interactions with the host immune system and produces significant year-to-year sequence turnover in the population of circulating viral strains. We develop a dynamical fitness model that predicts the evolution of the viral population from one year to the next. Two factors are shown to determine the fitness of a viral strain: adaptive changes, which are under positive selection, and deleterious mutations, which affect conserved viral functions such as protein stability. Combined with the influenza strain tree, this fitness model maps the adaptive history of influenza A. We discuss the implications of our results for the statistical theory of adaptive evolution in asexual populations. Based on this and related systems, we touch upon the fundamental question of when evolution can be predicted. Joint work with Marta Luksza, Columbia University.
Jørgensen, Gertrud; Herslund, Lise Byskov; Lund, Dorthe Hedensted;
beginning to be aware of the task, and some time will pass before it is integrated into mainstream urban governance. This chapter is based on work in progress. It covers urban governance and planning aspects of climate change adaptation as studied in the CLUVA project (CLimate change and Urban Vulnerability......Resilience of urban structures towards impacts of a changing climate is one of the emerging tasks that cities all over the world are facing at present. Effects of climate change take many forms, depending on local climate, spatial patterns, and socioeconomic structures. Cities are only just...... in Africa), as well as some experiences from Denmark. Focus is on the responses and capacities of urban authorities, strengths and weaknesses of the efforts, data needs and possible ways forward. The chapter concludes that many adaptation activities are taking place in the CLUVA case cities...
Full Text Available African cichlid fishes are an ideal system for studying explosive rates of speciation and the origin of diversity in adaptive radiation. Within the last few million years, more than 2000 species have evolved in the Great Lakes of East Africa, the largest adaptive radiation in vertebrates. These young species show spectacular diversity in their coloration, morphology and behavior. However, little is known about the genomic basis of this astonishing diversity. Recently, five African cichlid genomes were sequenced, including that of the Nile tilapia (Oreochromis niloticus, a basal and only relatively moderately diversified lineage, and the genomes of four representative endemic species of the adaptive radiations, Neolamprologus brichardi, Astatotilapia burtoni, Metriaclima zebra, and Pundamila nyererei. Using the tilapia genome as the reference genome, we generated a high-resolution genomic variation map, consisting of single nucleotide polymorphisms (SNPs, short insertions and deletions (indels, inversions and deletions. In total, around 18.8, 17.7, 17.0 and 17.0 million SNPs, 2.3, 2.2, 1.4 and 1.9 million indels, 262, 306, 162, and 154 inversions, and 3509, 2705, 2710 and 2634 deletions were inferred to have evolved in the N. brichardi, A. burtoni, P. nyererei and M. zebra respectively. Many of these variations affected the annotated gene regions in the genome. Different patterns of genetic variation were detected during the adaptive radiation of African cichlid fishes. For SNPs, the highest rate of evolution was detected in the common ancestor of N. brichardi, A. burtoni, P. nyererei and M. zebra. However, for the evolution of inversions and deletions, we found that the rates at the terminal taxa are substantially higher than the rates at the ancestral lineages. The high-resolution map provides an ideal opportunity to understand the genomic bases of the adaptive radiation of African cichlid fishes.
Hepatitis B virus （HBV） infection is a major public health problem worldwide. HBV is not directly cytotoxic toinfected hepatocytes; the clinical outcome of infectionresults from complicated interactions between the virusand the host immune system. In acute HBV infection,initiation of a broad, vigorous immune response is responsiblefor viral clearance and self-limited inflammatoryliver disease. Effective and coordinated innate andadaptive immune responses are critical for viral clearanceand the development of long-lasting immunity. Chronichepatitis B patients fail to mount efficient innate andadaptive immune responses to the virus. In particular,HBV-specific cytotoxic T cells, which are crucial for HBVclearance, are hyporesponsiveness to HBV infection.Accumulating experimental evidence obtained fromthe development of animal and cell line models hashighlighted the importance of innate immunity in theearly control of HBV spread. The virus has evolvedimmune escape strategies, with higher HBV loads andHBV protein concentrations associated with increasingimpairment of immune function. Therefore, treatmentof HBV infection requires inhibition of HBV replicationand protein expression to restore the suppressedhost immunity. Complicated interactions exist notonly between innate and adaptive responses, but alsoamong innate immune cells and different components ofadaptive responses. Improved insight into these complexinteractions are important in designing new therapeuticstrategies for the treatment HBV infection. In thisreview, we summarize the current knowledge regardingthe cross-talk between the innate and adaptive immuneresponses and among different immunocytes in HBVinfection.
Cheresiz, S. V.; Semenova, E. A.; Chepurnov, A. A.
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. PMID:26989413
Foot-and-mouth disease virus (FMDV) outer capsid proteins 1B, 1C and 1D contribute to the virus serotype distribution and antigenic variants that exist within each of the seven serotypes. This study presents a phylogenetic, genetic and antigenic analysis of the South African Territories (SAT) seroty...
Dixon, R; J. Smith; Guill, S.
Donor countries are providing financial and technical support for global climate change country studies to help African nations meet their reporting needs under the United Nations Framework Convention on Climate Change (UNFCCC). Technical assistance to complete vulnerability and adaptation assessments includes training of analysts, sharing of contemporary tools (e.g. simulation models), data and assessment techniques, information-sharing workshops and an international exchange programme for a...
Cheryl D Foxcroft
Full Text Available In response to the growing demand for a test of cognitive ability for South African adults, the Human Sciences Research Council (HSRC adapted the Wechsler Adult Intelligence Scales, third edition (WAIS-III for Englishspeaking South Africans. The standardisation sample included both first and second language English speakers who were either educated largely in English or Afrikaans. The purpose of this article is to critically examine the adaptation process undertaken by the HSRC when standardising the WAIS-III for English-speaking South Africans by deliberating whether sufficient attention was paid to establishing if the measure was equivalent for various groups of English first and second language test-takers. In performing this critical examination, international test adaptation guidelines and standards, psychometric conventions, and national and international research findings were contemplated. The general conclusion reached was that the equivalence of the WAIS-III across diverse language groups has not been unequivocally established and there are indications that some bias may exist for English second language test-takers, especially if they are black or Afrikaans-speaking. Based on these conclusions, recommendations are made regarding the way forward.
Carin I. Boshoff
Full Text Available African swine fever (ASF is an economically significant haemorrhagic disease of domestic pigs. It is caused by the African swine fever virus (ASFV, a deoxyribonucleic acid (DNAarbovirus. Argasid ticks of the genus Ornithodoros, which are widely distributed throughout southern Africa, play a primary role in virus maintenance and spread within the endemic sylvatic cycle. The ASF status of Swaziland is unknown, but this land-locked country is surrounded by ASF-positive countries, has a burgeoning pig industry and sylvatic cycle hosts present within its borders. In this first assessment of ASF status, warthog burrows in seven nature reserves and game management areas in Swaziland were investigated for tick and virus presence. Tick infestation rates of between 33.3% – 88.8% were recovered for the four Ornithodoros-infested reserves. A total of 562 ticks were screened for virus genome presence using a duplex Polymerase Chain Reaction (PCR that targets the C-terminal end of the p72 gene of the ASFV and confirms DNA integrity through amplification of the 16S rRNA tick host gene. All samples were negative for virus genome presence and positive for the tick genome target. Nucleotide sequencing of the latter confirmed that Ornithodoros ticks from Swaziland are identical to those from the Kruger National Park in South Africa across the gene region characterised. Whilst this first evaluation of ASF presence in Swaziland indicates that the virus does not appear to be present in the key virus vector, the presence of sylvatic cycle hosts, together with the country’s proximity to ASF-affected countries calls for expanded investigations and regular monitoring of the ASF status of Swaziland.
Boshoff, Carin I; Bastos, Armanda D S; Dube, Mzwandi M; Heath, Livio
African swine fever (ASF) is an economically significant haemorrhagic disease of domestic pigs. It is caused by the African swine fever virus (ASFV), a deoxyribonucleic acid (DNA)arbovirus. Argasid ticks of the genus Ornithodoros, which are widely distributed throughout southern Africa, play a primary role in virus maintenance and spread within the endemic sylvatic cycle. The ASF status of Swaziland is unknown, but this land-locked country is surrounded by ASF-positive countries, has a burgeoning pig industry and sylvatic cycle hosts present within its borders. In this first assessment of ASF status, warthog burrows in seven nature reserves and game management areas in Swaziland were investigated for tick and virus presence. Tick infestation rates of between 33.3% - 88.8% were recovered for the four Ornithodoros-infested reserves. A total of 562 ticks were screened for virus genome presence using a duplex Polymerase Chain Reaction (PCR) that targets the C-terminal end of the p72 gene of the ASFV and confirms DNA integrity through amplification of the 16S rRNA tick host gene. All samples were negative for virus genome presence and positive for the tick genome target. Nucleotide sequencing of the latter confirmed that Ornithodoros ticks from Swaziland are identical to those from the Kruger National Park in South Africa across the gene region characterised. Whilst this first evaluation of ASF presence in Swaziland indicates that the virus does not appear to be present in the key virus vector, the presence of sylvatic cycle hosts, together with the country's proximity to ASF-affected countries calls for expanded investigations and regular monitoring of the ASF status of Swaziland.
Escribano, José M; Galindo, Inmaculada; Alonso, Covadonga
Almost all viruses can be neutralized by antibodies. However, there is some controversy about antibody-mediated neutralization of African swine fever virus (ASFV) with sera from convalescent pigs and about the protective relevance of antibodies in experimentally vaccinated pigs. At present, there is no vaccine available for this highly lethal and economically relevant virus and all classical attempts to generate a vaccine have been unsuccessful. This failure has been attributed, in part, to what many authors describe as the absence of neutralizing antibodies. The findings of some studies clearly contradict the paradigm of the impossibility to neutralize ASFV by means of monoclonal or polyclonal antibodies. This review discusses scientific evidence of these types of antibodies in convalescent and experimentally immunized animals, the nature of their specificity, the neutralization-mediated mechanisms demonstrated, and the potential relevance of antibodies in protection. PMID:23159730
Thomson, G R; Gainaru, M D; Van Dellen, A F
Although there were no obvious signs of illness following experimental infection of young warthog with African swine fever virus, the animals developed viraemias between 10(2,4) and 10(3,6) HD50/ml within the first week of infection, and virus concentrations in a number of lymphatic tissues attained high levels (greater than or equal to 10(6) HD50/g). Unlike in blood, and to some extent in the spleen, virus titres in lymph nodes did not decline appreciable during the 33-day observation period, since at the end of the period lymphatic tissues from 2 warthog were still infectious for domestic pigs to which these tissues were fed. PMID:7454231
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
Orlando; Yaez; Graciano; Tejada; Peter; Neumann
<正>Dear Editor,The ability of the Western honey bee,Apis mellifera,to adapt to most climates of the world and the ongoing standardization of colony management has made this species of honey bees the most important species for crop pollination.In recent years,Peru emerged as a main exporter of industrial crops.This industry is mainly concentrated in the Peruvian coastal region,because the local climate permits off-season production
Sánchez-Matamoros, A; Nieto-Pelegrín, E; Beck, C; Rivera-Arroyo, B; Lecollinet, S; Sailleau, C; Zientara, S; Sánchez-Vizcaíno, J M
African horse sickness (AHS) is considered a fatal re-emergent vector-borne disease of horses. In the absence of any effective treatment for AHS, vaccination remains the most effective form of disease control. The new generation of vaccines, such as one based on purified, inactivated AHS virus (AHSV, serotype 4), which does not induce antibodies against non-structural protein 3 (NS3), enables the development of diagnostic methods that differentiate infected from vaccinated animals (DIVA assays). As detecting AHS in AHSV-free countries may lead to restrictions on international animal movements and thereby cause significant economic damage, these DIVA assays are crucial for reducing movement restrictions. In this article, we describe a Luminex-based multiplex assay for DIVA diagnosis of AHS, and we validate it in a duplex format to detect antibodies against structural protein 7 (VP7) and NS3 in serum samples from horses vaccinated with inactivated AHSV4 vaccine or infected with a live virus of the same serotype. Results of the Luminex-based assay for detecting anti-NS3 antibodies showed good positive correlation with results from an in-house enzyme-linked immunosorbent assay (ELISA). Thus, the Luminex-based technique described here may allow multiplex DIVA antibody detection in a single sample in less than 2 h, and it may prove adaptable for the development of robust, multiplex serological assays. PMID:27090377
Johnston, Sara C; Briese, Thomas; Bell, Todd M; Pratt, William D; Shamblin, Joshua D; Esham, Heather L; Donnelly, Ginger C; Johnson, Joshua C; Hensley, Lisa E; Lipkin, W Ian; Honko, Anna N
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.
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.
Muschick, Moritz; Nosil, Patrik; Roesti, Marius; Dittmann, Marie Theres; Harmon, Luke; Salzburger, Walter
Adaptive radiation (AR) is a key process in the origin of organismal diversity. However, the evolution of trait disparity in connection with ecological specialization is still poorly understood. Available models for vertebrate ARs predict that diversification occurs in the form of temporal stages driven by different selective forces. Here, we investigate the AR of cichlid fishes in East African Lake Tanganyika and use macroevolutionary model fitting to evaluate whether diversification happened in temporal stages. Six trait complexes, for which we also provide evidence of their adaptiveness, are analysed with comparative methods: body shape, pharyngeal jaw shape, gill raker traits, gut length, brain weight and body coloration. Overall, we do not find strong evidence for the 'stages model' of AR. However, our results suggest that trophic traits diversify earlier than traits implicated in macrohabitat adaptation and that sexual communication traits (i.e. coloration) diversify late in the radiation. PMID:25274371
Kasembeli, Alex N; Duarte, Raquel; Ramsay, Michèle; Naicker, Saraladevi
Chronic kidney disease (CKD) is a major public health problem worldwide with the estimated incidence growing by approximately 6% annually. There are striking ethnic differences in the prevalence of CKD such that, in the United States, African Americans have the highest prevalence of CKD, four times the incidence of end stage renal disease when compared to Americans of European ancestry suggestive of genetic predisposition. Diabetes mellitus, hypertension and human immunodeficiency virus (HIV) infection are the major causes of CKD. HIV-associated nephropathy (HIVAN) is an irreversible form of CKD with considerable morbidity and mortality and is present predominantly in people of African ancestry. The APOL1 G1 and G2 alleles were more strongly associated with the risk for CKD than the previously examined MYH9 E1 risk haplotype in individuals of African ancestry. A strong association was reported in HIVAN, suggesting that 50% of African Americans with two APOL1 risk alleles, if untreated, would develop HIVAN. However these two variants are not enough to cause disease. The prevailing belief is that modifying factors or second hits (including genetic hits) underlie the pathogenesis of kidney disease. This work reviews the history of genetic susceptibility of CKD and outlines current theories regarding the role for APOL1 in CKD in the HIV era.
Full Text Available Members of the Mycobacterium tuberculosis complex (MTC cause tuberculosis (TB in both animals and humans. In this article, three animal-adapted MTC strains that are endemic to the southern African subregion – that is, Mycobacterium suricattae, Mycobacterium mungi, and the dassie bacillus – are reviewed with a focus on clinical and pathological presentations, geographic distribution, genotyping methods, diagnostic tools and evolution. Moreover, factors influencing the transmission and establishment of TB pathogens in novel host populations, including ecological, immunological and genetic factors of both the host and pathogen, are discussed. The risks associated with these infections are currently unknown and further studies will be required for greater understanding of this disease in the context of the southern African ecosystem.Keywords: dassie bacillus; ecology; evolution; host jump; Mycobacterium mungi; Mycobacterium suricattae; Mycobacterium tuberculosis complex; phylogeny
de Waal, Tania; Liebenberg, Danica; Venter, Gert J; Mienie, Charlotte Ms; van Hamburg, Huib
African horse sickness (AHS) is an infectious, non-contagious arthropod-borne disease of equids, caused by the African horse sickness virus (AHSV), an orbivirus of the Reoviridae family. It is endemic in sub-Saharan Africa and thought to be the most lethal viral disease of horses. This study focused on detection of AHSV in Culicoides imicola (Diptera: Ceratopogonidae) pools by the application of a RT-qPCR. Midges were fed on AHSV-infected blood. A single blood-engorged female was allocated to pools of unfed nulliparous female midges. Pool sizes varied from 1 to 200. RNA was extracted and prepared for RT-qPCR. The virus was successfully detected and the optimal pool size for the limit of detection of the virus was determined at a range between 1 to 25. Results from this investigation highlight the need for a standardized protocol for AHSV investigation in Culicoides midges especially for comparison among different studies and for the determination of infection rate. PMID:27232141
Jörn E Schmitz
Full Text Available African green monkeys (AGM and other natural hosts for simian immunodeficiency virus (SIV do not develop an AIDS-like disease following SIV infection. To evaluate differences in the role of SIV-specific adaptive immune responses between natural and nonnatural hosts, we used SIV(agmVer90 to infect vervet AGM and pigtailed macaques (PTM. This infection results in robust viral replication in both vervet AGM and pigtailed macaques (PTM but only induces AIDS in the latter species. We delayed the development of adaptive immune responses through combined administration of anti-CD8 and anti-CD20 lymphocyte-depleting antibodies during primary infection of PTM (n = 4 and AGM (n = 4, and compared these animals to historical controls infected with the same virus. Lymphocyte depletion resulted in a 1-log increase in primary viremia and a 4-log increase in post-acute viremia in PTM. Three of the four PTM had to be euthanized within 6 weeks of inoculation due to massive CMV reactivation and disease. In contrast, all four lymphocyte-depleted AGM remained healthy. The lymphocyte-depleted AGM showed only a trend toward a prolongation in peak viremia but the groups were indistinguishable during chronic infection. These data show that adaptive immune responses are critical for controlling disease progression in pathogenic SIV infection in PTM. However, the maintenance of a disease-free course of SIV infection in AGM likely depends on a number of mechanisms including non-adaptive immune mechanisms.
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...
Nakouné, Emmanuel; Kamgang, Basile; Berthet, Nicolas; Manirakiza, Alexandre; Kazanji, Mirdad
Background Rift Valley fever virus (RVFV) causes a viral zoonosis, with discontinuous epizootics and sporadic epidemics, essentially in East Africa. Infection with this virus causes severe illness and abortion in sheep, goats, and cattle as well as other domestic animals. Humans can also be exposed through close contact with infectious tissues or by bites from infected mosquitoes, primarily of the Aedes and Culex genuses. Although the cycle of RVFV infection in savannah regions is well documented, its distribution in forest areas in central Africa has been poorly investigated. Methodology/Principal Findings To evaluate current circulation of RVFV among livestock and humans living in the Central African Republic (CAR), blood samples were collected from sheep, cattle, and goats and from people at risk, such as stock breeders and workers in slaughterhouses and livestock markets. The samples were tested for anti-RVFV immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies. We also sequenced the complete genomes of two local strains, one isolated in 1969 from mosquitoes and one isolated in 1985 from humans living in forested areas. The 1271 animals sampled comprised 727 cattle, 325 sheep, and 219 goats at three sites. The overall seroprevalence of anti-RVFV IgM antibodies was 1.9% and that of IgG antibodies was 8.6%. IgM antibodies were found only during the rainy season, but the frequency of IgG antibodies did not differ significantly by season. No evidence of recent RVFV infection was found in 335 people considered at risk; however, 16.7% had evidence of past infection. Comparison of the nucleotide sequences of the strains isolated in the CAR with those isolated in other African countries showed that they belonged to the East/Central African cluster. Conclusion and significance This study confirms current circulation of RVFV in CAR. Further studies are needed to determine the potential vectors involved and the virus reservoirs. PMID:27760144
Guthrie, Alan J; Quan, Melvyn; Lourens, Carina W; Audonnet, Jean-Christophe; Minke, Jules M; Yao, Jiansheng; He, Ling; Nordgren, Robert; Gardner, Ian A; Maclachlan, N James
We describe the development and preliminary characterization of a recombinant canarypox virus vectored (ALVAC) vaccine for protective immunization of equids against African horse sickness virus (AHSV) infection. Horses (n=8) immunized with either of two concentrations of recombinant canarypox virus vector (ALVAC-AHSV) co-expressing synthetic genes encoding the outer capsid proteins (VP2 and VP5) of AHSV serotype 4 (AHSV-4) developed variable titres (horse immunized with a commercial recombinant canarypox virus vectored vaccine expressing the haemagglutinin genes of two equine influenza H3N8 viruses was seronegative to AHSV and following infection with virulent AHSV-4 developed pyrexia, thrombocytopenia and marked oedema of the supraorbital fossae typical of the "dikkop" or cardiac form of African horse sickness. AHSV was detected by virus isolation and quantitative reverse transcriptase polymerase chain reaction in the blood of the control horse from 8 days onwards after challenge infection whereas AHSV was not detected at any time in the blood of the ALVAC-AHSV vaccinated horses. The control horse seroconverted to AHSV by 2 weeks after challenge infection as determined by both virus neutralization and ELISA assays, whereas six of eight of the ALVAC-AHSV vaccinated horses did not seroconvert by either assay following challenge infection with virulent AHSV-4. These data confirm that the ALVAC-AHSV vaccine will be useful for the protective immunization of equids against African horse sickness, and avoids many of the problems inherent to live-attenuated AHSV vaccines.
Below, Till; ARTNER Astrid; Siebert, Rosemarie; SIEBER STEFAN
This paper discusses micro-level practices for adapting to climate change that are available to small-scale farmers in Africa. The analysis is based on a review of 17 studies about practices that boost small-scale farmers¿ resilience or reduce their vulnerability to observed or expected changes in climate; it includes data from more than 16 countries in Africa, the Americas, Europe, and Asia. The review shows that African smallholders are already using a wide variety of creative practices to ...
El Garch, H; Crafford, J E; Amouyal, P; Durand, P Y; Edlund Toulemonde, C; Lemaitre, L; Cozette, V; Guthrie, A; Minke, J M
A recombinant canarypox virus vectored vaccine co-expressing synthetic genes encoding outer capsid proteins, VP2 and VP5, of African horse sickness virus (AHSV) serotype 4 (ALVAC(®)-AHSV4) has been demonstrated to fully protect horses against homologous challenge with virulent field virus. Guthrie et al. (2009) detected weak and variable titres of neutralizing antibody (ranging from horses received two vaccinations twenty-eight days apart and three horses remained unvaccinated. The detection of VP2/VP5 specific IFN-γ responses was assessed by enzyme linked immune spot (ELISpot) assay and clearly demonstrated that all ALVAC(®)-AHSV4 vaccinated horses developed significant IFN-γ production compared to unvaccinated horses. More detailed immune responses obtained by flow cytometry demonstrated that ALVAC(®)-AHSV4 vaccinations induced immune cells, mainly CD8(+) T cells, able to recognize multiple T-epitopes through all VP2 and only the N-terminus sequence of VP5. Neither VP2 nor VP5 specific IFN-γ responses were detected in unvaccinated horses. Overall, our data demonstrated that an experimental recombinant canarypox based vaccine induced significant CMI specific for both VP2 and VP5 proteins of AHSV4.
Argilaguet, Jordi M; Pérez-Martín, Eva; López, Sergio; Goethe, Martin; Escribano, J M; Giesow, Katrin; Keil, Günther M; Rodríguez, Fernando
Lack of vaccines and efficient control measures complicate the control and eradication of African swine fever (ASF). Limitations of conventional inactivated and attenuated virus-based vaccines against African swine fever virus (ASFV) highlight the need to use new technologies to develop efficient and safe vaccines against this virus. With this aim in mind, in this study we have constructed BacMam-sHAPQ, a baculovirus based vector for gene transfer into mammalian cells, expressing a fusion protein comprising three in tandem ASFV antigens: p54, p30 and the extracellular domain of the viral hemagglutinin (secretory hemagglutinin, sHA), under the control of the human cytomegalovirus immediate early promoter (CMVie). Confirming its correct in vitro expression, BacMam-sHAPQ induced specific T-cell responses directly after in vivo immunization. Conversely, no specific antibody responses were detectable prior to ASFV challenge. The protective potential of this recombinant vaccine candidate was tested by a homologous sublethal challenge with ASFV following immunization. Four out of six immunized pigs remained viremia-free after ASFV infection, while the other two pigs showed similar viremic titres to control animals. The protection afforded correlated with the presence of a large number of virus-specific IFNγ-secreting T-cells in blood at 17 days post-infection. In contrast, the specific antibody levels observed after ASFV challenge in sera from BacMam-sHAPQ immunized pigs were indistinguishable from those found in control pigs. These results highlight the importance of the cellular responses in protection against ASFV and point towards BacMam vectors as potential tools for future vaccine development.
Rubio, C; Cubillo, M A; Hooghuis, H; Sanchez-Vizcaino, J M; Diaz-Laviada, M; Plateau, E; Zientara, S; Crucière, C; Hamblin, C
The mortality rate in susceptible populations of horses during an epizootic of African horse sickness (AHS) may be in excess of 90%. Rapid and reliable assays are therefore essential for the confirmation of clinical diagnoses and to enable control strategies to be implemented without undue delay. One of the major objectives of a recent European Union funded project was the validation of newly developed diagnostic assays which are rapid, sensitive, highly reproducible and inexpensive, for the detection of African horse sickness virus (AHSV) antigens and antibodies. The Laboratorio de Sanidad y Produccion Animal (LSPA) in Algete, Spain was charged with the responsibility of co-ordinating and supplying samples of viruses and antisera to the participating laboratories in Spain, France and the United Kingdom. The panels comprised 76 antigen samples for assay by indirect sandwich ELISAs and 53 serum samples for antibody detection by either indirect or competitive ELISAs. Results generated by ELISA for each laboratory were analysed in LSPA in terms of their relative sensitivities and specificities. There was a good agreement between the ELISAs used for either antigen or antibody detection. The participating groups agreed that any field sample giving a doubtful result would always be retested by ELISA and an alternative assay.
Li, Jun; Yu, Xinfen; Pu, Xiaoying; Xie, Li; Sun, Yongxiang; Xiao, Haixia; Wang, Fenjuan; Din, Hua; Wu, Ying; Liu, Di; Zhao, Guoqiu; Liu, Jun; Pan, Jingcao
A novel H7N9 influenza A virus has been discovered as the causative identity of the emerging acute respiratory infection cases in Shanghai, China. This virus has also been identified in cases of infection in the neighboring area Hangzhou City in Zhejiang Province. In this study, epidemiologic, clinical, and virological data from three patients in Hangzhou who were confirmed to be infected by the novel H7N9 influenza A virus were collected and analyzed. Human respiratory specimens and chicken feces from a contacted free market were tested for influenza virus by real-time reverse transcription PCR (RT-PCR) and sequencing. The clinical features of the three cases were similar featured with high fever and severe respiratory symptoms; however, only one of the patients died. A certain degree of diversity was observed among the three Hangzhou viruses sequenced from human samples compared with other reported H7N9 influenza A viruses. The sequences of the novel avian-origin H7N9 influenza viruses from Hangzhou City contained important amino acid substitutions related to human adaptation. One of the Hangzhou viruses had gained a novel amino acid substitution (Q226I) in the receptor binding region of hemagglutinin. More importantly, the virus sequenced from the chicken feces had a 627E substitution in the PB2 protein instead of the mammalian-adapted 627K substitution that was found in the PB2 proteins from the Hangzhou viruses from the three patients. Therefore, the newly-emerging H7N9 virus might be under adaptation pressure that will help it "jump" from avian to human hosts. The significance of these substitutions needs further exploration, with both laboratory experiments and extensive field surveillance. PMID:23657795
Nabalayo Wekesa, Sabenzia; Kiprotich Sangula, Abraham; Belsham, Graham;
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.......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...
Brian W. van Wilgen
Full Text Available This paper reviews the experience gained in three South African national parks (Kruger, Table Mountain and Bontebok with regard to the adaptive management of fire for the conservation of biodiversity. In the Kruger National Park, adaptive approaches have evolved over the past 15 years, beginning initially as a form of ‘informed trial and error’, but progressing towards active adaptive management in which landscape-scale, experimental burning treatments are being applied in order to learn. In the process, significant advances in understanding regarding the role and management of fire have been made. Attempts have been made to transfer the approaches developed in Kruger National Park to the other two national parks. However, little progress has been made to date, both because of a failure to provide an agreed context for the introduction of adaptive approaches, and because (in the case of Bontebok National Park too little time has passed to be able to make an assessment. Fire management interventions, ultimately, will manifest themselves in terms of biodiversity outcomes, but definite links between fire interventions and biodiversity outcomes have yet to be made.Conservation implications: Significant challenges face the managers of fire-prone and fire adapted ecosystems, where the attainment of ecosystem goals may require approaches (like encouraging high-intensity fires at hot and dry times of the year that threaten societal goals related to safety. In addition, approaches to fire management have focused on encouraging particular fire patterns in the absence of a sound understanding of their ecological outcomes. Adaptive management offers a framework for addressing these issues, but will require higher levels of agreement, monitoring and assessment than have been the case to date.
McKillan, John; McMenamy, Michael; Hjertner, Bernt;
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 not...
Fansiri, Thanyalak; Pongsiri, Arissara; Klungthong, Chonticha; Ponlawat, Alongkot; Thaisomboonsuk, Butsaya; Lambrechts, Louis; Jarman, Richard G; Scott, Thomas W.
International audience Despite their epidemiological importance, the evolutionary forces that shape the spatial structure of dengue virus genetic diversity are not fully understood. Fine-scale genetic structure of mosquito vector populations and evidence for genotype 9 genotype interactions between dengue viruses and their mosquito vectors are consistent with the hypothesis that the geographical distribution of dengue virus genetic diversity may reflect viral adaptation to local mosquito p...
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...
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.
Pelto, Debra J.; Sadler, Georgia Robins; Njoku, Ogo; Rodriguez, Maria Carina; Villagra, Cristina; Malcarne, Vanessa L.; Riley, Natasha E.; Behar, Alma I.; Jandorf, Lina
The pilot study reported in this article culturally and linguistically adapted an educational intervention to promote cancer clinical trials (CCTs) participation among Latinas/os and African Americans. The single-session slide presentation with embedded videos, originally developed through a campus-community partnership in Southern California, was…
Ward, Earlise C; Brown, Roger L
The purpose of this article is to describe development of a culturally adapted depression intervention (Oh Happy Day Class, OHDC) designed for African American adults experiencing major depressive disorder (MDD). This project included 2 pilot studies testing the feasibility and acceptability of the OHDC and examining short-term effects of the OHDC in reducing symptoms of MDD. The OHDC is a 2.5-hr weekly, culturally specific, cognitive behavioral, group counseling intervention for 12 weeks. Cultural adaptations of the OHDC are based on the ecological validity and culturally sensitive framework, along with an Afrocentric paradigm. Fifty African American participants with MDD were enrolled (15 in Pilot I and 35 in Pilot II). All participants in Pilots I and II received the 12-week intervention and completed assessments at baseline, mid-intervention, end-intervention, and 3 months postintervention. General linear mixed modeling for assessment of pre-post longitudinal data analysis was conducted. Results for Pilot I showed 73% of participants completed the full OHDC, a statistically significant decline in depression symptoms from pre- to postintervention, and a 0.38 effect size. Participants were very satisfied with the OHDC. In Pilot II, 66% of participants completed the full OHDC, and there was a significant pre-post intervention decrease in depression symptoms. For men, the OHDC showed a 1.01 effect size and for women, a 0.41 effect size. Both men and women were very satisfied with the OHDC based on the satisfaction measure. These promising findings are discussed with a focus on future plans for examining efficacy of the OHDC in a large-scale, randomized, control trial.
Foley, Brian T [Los Alamos National Laboratory; Korber, Bette T [Los Alamos National Laboratory
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.
Thoromo, Jonas; Simulundu, Edgar; Chambaro, Herman M; Mataa, Liywalii; Lubaba, Caesar H; Pandey, Girja S; Takada, Ayato; Misinzo, Gerald; Mweene, Aaron S
In early 2015, a highly fatal haemorrhagic disease of domestic pigs resembling African swine fever (ASF) occurred in North Western, Copperbelt, and Lusaka provinces of Zambia. Molecular diagnosis by polymerase chain reaction targeting specific amplification of p72 (B646L) gene of ASF virus (ASFV) was conducted. Fourteen out of 16 domestic pigs from the affected provinces were found to be positive for ASFV. Phylogenetic analyses based on part of the p72 and the complete p54 (E183L) genes revealed that all the ASFVs detected belonged to genotypes I and Id, respectively. Additionally, epidemiological data suggest that the same ASFV spread from Lusaka to other provinces possibly through uncontrolled and/or illegal pig movements. Although the origin of the ASFV that caused outbreaks in domestic pigs in Zambia could not be ascertained, it appears likely that the virus may have emerged from within the country or region, probably from a sylvatic cycle. It is recommended that surveillance of ASF, strict biosecurity, and quarantine measures be imposed in order to prevent further spread and emergence of new ASF outbreaks in Zambia. PMID:27247062
Müller, Marcel A.; Devignot, Stéphanie; Lattwein, Erik; Corman, Victor Max; Maganga, Gaël D.; Gloza-Rausch, Florian; Binger, Tabea; Vallo, Peter; Emmerich, Petra; Cottontail, Veronika M.; Tschapka, Marco; Oppong, Samuel; Drexler, Jan Felix; Weber, Friedemann; Leroy, Eric M.; Drosten, Christian
Crimean Congo hemorrhagic fever virus (CCHFV) is a highly virulent tick-borne pathogen that causes hemorrhagic fever in humans. The geographic range of human CCHF cases largely reflects the presence of ticks. However, highly similar CCHFV lineages occur in geographically distant regions. Tick-infested migratory birds have been suggested, but not confirmed, to contribute to the dispersal. Bats have recently been shown to carry nairoviruses distinct from CCHFV. In order to assess the presence of CCHFV in a wide range of bat species over a wide geographic range, we analyzed 1,135 sera from 16 different bat species collected in Congo, Gabon, Ghana, Germany, and Panama. Using a CCHFV glycoprotein-based indirect immunofluorescence test (IIFT), we identified reactive antibodies in 10.0% (114/1,135) of tested bats, pertaining to 12/16 tested species. Depending on the species, 3.6%–42.9% of cave-dwelling bats and 0.6%–7.1% of foliage-living bats were seropositive (two-tailed t-test, p = 0.0447 cave versus foliage). 11/30 IIFT-reactive sera from 10 different African bat species had neutralizing activity in a virus-like particle assay. Neutralization of full CCHFV was confirmed in 5 of 7 sera. Widespread infection of cave-dwelling bats may indicate a role for bats in the life cycle and geographic dispersal of CCHFV. PMID:27217069
Hernaez, Bruno; Alonso, Covadonga
African swine fever virus (ASFV) is a large DNA virus that enters host cells after receptor-mediated endocytosis and depends on acidic cellular compartments for productive infection. The exact cellular mechanism, however, is largely unknown. In order to dissect ASFV entry, we have analyzed the major endocytic routes using specific inhibitors and dominant negative mutants and analyzed the consequences for ASFV entry into host cells. Our results indicate that ASFV entry into host cells takes place by clathrin-mediated endocytosis which requires dynamin GTPase activity. Also, the clathrin-coated pit component Eps15 was identified as a relevant cellular factor during infection. The presence of cholesterol in cellular membranes, but not lipid rafts or caveolae, was found to be essential for a productive ASFV infection. In contrast, inhibitors of the Na+/H+ ion channels and actin polymerization inhibition did not significantly modify ASFV infection, suggesting that macropinocytosis does not represent the main entry route for ASFV. These results suggest a dynamin-dependent and clathrin-mediated endocytic pathway of ASFV entry for the cell types and viral strains analyzed. PMID:19939916
Guinat, Claire; Gogin, Andrey; Blome, Sandra; Keil, Guenther; Pollin, Reiko; Pfeiffer, Dirk U; Dixon, Linda
African swine fever (ASF) is a major threat to the pig industry in Europe. Since 2007, ASF outbreaks have been ongoing in the Caucasus, Eastern Europe and the Baltic countries, causing severe economic losses for many pig farmers and pork producers. In addition, the number of ASF cases in wild boar populations has dramatically increased over the past few years. Evidence supports direct contact with infectious domestic pigs and wild boars, and consumption of contaminated feed, as the main transmission routes of ASF virus (ASFV) to domestic pigs. However, significant knowledge gaps highlight the urgent need for research to investigate the dynamics of indirect transmission via the environment, the minimal infective doses for contaminated feed ingestion, the probability of effective contacts between infectious wild boars and domestic pigs, the potential for recovered animals to become carriers and a reservoir for transmission, the potential virus persistence within wild boar populations and the influence of human behaviour for the spread of ASFV. This will provide an improved scientific basis to optimise current interventions and develop new tools and strategies to reduce the risk of ASFV transmission to domestic pigs.
Müller, Marcel A; Devignot, Stéphanie; Lattwein, Erik; Corman, Victor Max; Maganga, Gaël D; Gloza-Rausch, Florian; Binger, Tabea; Vallo, Peter; Emmerich, Petra; Cottontail, Veronika M; Tschapka, Marco; Oppong, Samuel; Drexler, Jan Felix; Weber, Friedemann; Leroy, Eric M; Drosten, Christian
Crimean Congo hemorrhagic fever virus (CCHFV) is a highly virulent tick-borne pathogen that causes hemorrhagic fever in humans. The geographic range of human CCHF cases largely reflects the presence of ticks. However, highly similar CCHFV lineages occur in geographically distant regions. Tick-infested migratory birds have been suggested, but not confirmed, to contribute to the dispersal. Bats have recently been shown to carry nairoviruses distinct from CCHFV. In order to assess the presence of CCHFV in a wide range of bat species over a wide geographic range, we analyzed 1,135 sera from 16 different bat species collected in Congo, Gabon, Ghana, Germany, and Panama. Using a CCHFV glycoprotein-based indirect immunofluorescence test (IIFT), we identified reactive antibodies in 10.0% (114/1,135) of tested bats, pertaining to 12/16 tested species. Depending on the species, 3.6%-42.9% of cave-dwelling bats and 0.6%-7.1% of foliage-living bats were seropositive (two-tailed t-test, p = 0.0447 cave versus foliage). 11/30 IIFT-reactive sera from 10 different African bat species had neutralizing activity in a virus-like particle assay. Neutralization of full CCHFV was confirmed in 5 of 7 sera. Widespread infection of cave-dwelling bats may indicate a role for bats in the life cycle and geographic dispersal of CCHFV. PMID:27217069
Hipp, Katharina; Schäfer, Benjamin; Kepp, Gabi; Jeske, Holger
The capsid proteins (CPs) of geminiviruses combine multiple functions for packaging the single-stranded viral genome, insect transmission and shuttling between the nucleus and the cytoplasm. African cassava mosaic virus (ACMV) CP was expressed in fission yeast, and purified by SDS gel electrophoresis. After tryptic digestion of this protein, mass spectrometry covered 85% of the amino acid sequence and detected three N-terminal phosphorylation sites (threonine 12, serines 25 and 62). Differential centrifugation of cell extracts separated the CP into two fractions, the supernatant and pellet. Upon isopycnic centrifugation of the supernatant, most of the CP accumulated at densities typical for free proteins, whereas the CP in the pellet fraction showed a partial binding to nucleic acids. Size-exclusion chromatography of the supernatant CP indicated high order complexes. In DNA binding assays, supernatant CP accelerated the migration of ssDNA in agarose gels, which is a first hint for particle formation. Correspondingly, CP shifted ssDNA to the expected densities of virus particles upon isopycnic centrifugation. Nevertheless, electron microscopy did not reveal any twin particles, which are characteristic for geminiviruses. PMID:27399762
A multiplex PCR for simultaneous detection of classical swine fever virus, African swine fever virus, highly pathogenic porcine reproductive and respiratory syndrome virus, porcine reproductive and respiratory syndrome virus and pseudorabies in swines.
Hu, L; Lin, X Y; Yang, Z X; Yao, X P; Li, G L; Peng, S Z; Wang, Y
In this assay, we developed and evaluated a multiplex PCR (mPCR) for its ability in detecting multiple infections of swine simultaneously. Four pairs of primers were used to detect five viruses. Specific primers were designed for classical swine fever virus (CSFV), African swine fever virus (ASFV) and pseudorabies (PRV). A pair of primers was designed prudently for two different types of porcine reproductive and respiratory syndrome virus that respectively were porcine reproductive and respiratory syndrome virus (PRRSV), highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV). The detection limits of the mPCR were 1.09 × 10⁴, 1.50 × 10³, 2.10 × 10³, 1.30 × 10³ and 8.97 × 10² copies/reaction for CSFV, ASFV, HP-PRRSV, PRRSV and PRV, respectively. A total of 49 clinical specimens were tested by the mPCR, and the result showed that co-infection by two or three viruses was 51%. In conclusion, the PCR is a useful tool for clinical diagnosis of not only single infections but also mixed infections in swines. PMID:26812812
Nabalayo Wekesa, Sabenzia; Kiprotich Sangula, Abraham; Belsham, Graham; Tjørnehøj, Kirsten; Vincent B Muwanika; Gakuya, Francis; Mijele, Dominic; Redlef Siegismund, Hans
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 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...
Hirsch, V.; Riedel, N.; Kornfeld, H; Kanki, P J; M Essex; Mullins, J I
Simian T-lymphotropic retroviruses with structural, antigenic, and cytopathic features similar to the etiologic agent of human acquired immunodeficiency syndrome, human T-lymphotropic virus type III/lymphadenopathy-associated virus (HTLV-III/LAV), have been isolated from a variety of primate species including African green monkeys (STLV-IIIAGM). This report describes nucleic acid cross-reactivity between STLV-IIIAGM and HTLV-III/LAV, molecular cloning of the STLV-IIIAGM genome, and evaluation...
Monnica T. Williams
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.
Bernard, Jennifer; Hutet, Evelyne; Paboeuf, Frédéric; Randriamparany, Tantely; Holzmuller, Philippe; Lancelot, Renaud; Rodrigues, Valérie; Vial, Laurence; Le Potier, Marie-Frédérique
African swine fever is a haemorrhagic disease in pig production that can have disastrous financial consequences for farming. No vaccines are currently available and animal slaughtering or area zoning to restrict risk-related movements are the only effective measures to prevent the spread of the disease. Ornithodoros soft ticks are known to transmit the African swine fever virus (ASFV) to pigs in farms, following the natural epidemiologic cycle of the virus. Tick saliva has been shown to modulate the host physiological and immunological responses during feeding on skin, thus affecting viral infection. To better understand the interaction between soft tick, ASFV and pig at the bite location and the possible influence of tick saliva on pig infection by ASFV, salivary gland extract (SGE) of Ornithodoros porcinus, co-inoculated or not with ASFV, was used for intradermal auricular inoculation. Our results showed that, after the virus triggered the disease, pigs inoculated with virus and SGE presented greater hyperthermia than pigs inoculated with virus alone. The density of Langerhans cells was modulated at the tick bite or inoculation site, either through recruitment by ASFV or inhibition by SGE. Additionally, SGE and virus induced macrophage recruitment each. This effect was enhanced when they were co-inoculated. Finally, the co-inoculation of SGE and virus delayed the early local spread of virus to the first lymph node on the inoculation side. This study has shown that the effect of SGE was powerful enough to be quantified in pig both on the systemic and local immune response. We believe this model should be developed with infected tick and could improve knowledge of both tick vector competence and tick saliva immunomodulation. PMID:26828597
Redrejo-Rodríguez, Modesto; Alexander A Ishchenko; Saparbaev, Murat K.; Salas, María L.; Salas, José
African swine fever virus (ASFV) encodes an AP endonuclease (pE296R) which is essential for virus growth in swine macrophages. We show here that the DNA repair functions of pE296R (AP endonucleolytic, 3′ → 5′ exonuclease, 3′-diesterase and nucleotide incision repair (NIR) activities) and DNA binding are inhibited by reducing agents. Protein pE296R contains one intramolecular disulfide bond, whose disruption by reducing agents might perturb the interaction of the viral AP endonuclease with the...
Zakaryan, Hovakim; Karalova, Elena; Voskanyan, Henrik; Ter-Pogossyan, Zarine; Nersisyan, Narek; Hakobyan, Astghik; Saroyan, David; Karalyan, Zaven
African swine fever is a highly contagious hemorrhagic disease of pigs caused by African swine fever virus (ASFV). Hemorrhages are the most frequently reported lesions in acute and subacute forms of ASF. Hemorrhagic lesions are accompanied by impaired hemostasis, which includes thrombocytopenia and changes in the coagulation system. In the present study, experimental infection was conducted to elucidate whether a highly virulent ASFV genotype II circulating in the Trans-Caucasus and Eastern Europe affects the hemostasis of infected pigs. Platelet count changes and platelet size, as well as coagulation parameters were evaluated upon experimental infection. In contrast to other ASFV strains, ASFV genotype II showed a significant decrease in the number of platelets from 3rd dpi onwards. Furthermore, a decrease in platelet size was observed throughout the entire period of experiment. A significant increase in the number of platelet aggregates was observed from the beginning of infection. Unlike other ASFV strains, ASFV genotype II induced a slight shortening of an activated partial thromboplastin time (aPTT) throughout the experiment. Thrombin time (TT) was prolonged from day 5 onwards, whereas no changes in prothrombin time (PT) were found upon infection. The level of d-dimers was permanently higher than in control with a peak on day 3 post-infection. ASFV induced a significant decrease in the level of fibrinogen from day 5 till the end of experiment. Thus, it can be concluded that ASFV genotype II isolated in Armenia affects the hemostasis of infected pigs and causes changes that differ from that of other ASFV strains described previously.
de Vos, C J; Hoek, C A; Nodelijk, G
African horse sickness (AHS) is a vector-borne viral disease of equines that is transmitted by Culicoides spp. and can have severe consequences for the horse industry in affected territories. A study was performed to assess the risk of introducing AHS virus (AHSV) into the Netherlands (P_AHS) by international equine movements. The goal of this study was to provide more insight into (a) the regions and equine species that contribute most to this risk, (b) the seasonal variation in this risk, and (c) the effectiveness of measures to prevent introduction of AHSV. Countries worldwide were grouped into three risk regions: (1) high risk, i.e., those countries in which the virus is presumed to circulate, (2) low risk, i.e., those countries that have experienced outbreaks of AHS in the past and/or where the main vector of AHS, Culicoides imicola, is present, and (3) very low risk, i.e., all other countries. A risk model was constructed estimating P_AHS taking into account the probability of release of AHSV in the Netherlands and the probability that local vectors will subsequently transmit the virus to local hosts. Model calculations indicated that P_AHS is very low with a median value of 5.1×10(-4)/year. The risk is highest in July and August, while equine movements in the period October till March pose a negligible risk. High and low risk regions contribute most to P_AHS with 31% and 53%, respectively. Importations of donkeys and zebras constitute the highest risk of AHSV release from high risk regions, while international movements of competition horses constitute the highest risk of AHSV release from low and very low risk regions. Preventive measures currently applied reduce P_AHS by 46% if compared to a situation in which no preventive measures are applied. A prolonged and more effective quarantine period in high risk regions and more stringent import regulations for low risk regions could further reduce P_AHS. Large uncertainty was involved in estimating model input
Robinson, Beatrice E.; Galbraith, Jennifer S.; Lund, Sharon M.; Hamilton, Autumn R.; Shankle, Michael D.
We describe the process of adapting a community-level, evidence-based behavioral intervention (EBI), Community PROMISE, for HIV-positive African American men who have sex with men (AAMSM). The Centers for Disease Control and Prevention (CDC) Map of the Adaptation Process (MAP) guided the adaptation process for this new target population by two…
Konstantin A Tsetsarkin
Full Text Available Between 2005 and 2007 Chikungunya virus (CHIKV caused its largest outbreak/epidemic in documented history. An unusual feature of this epidemic is the involvement of Ae. albopictus as a principal vector. Previously we have demonstrated that a single mutation E1-A226V significantly changed the ability of the virus to infect and be transmitted by this vector when expressed in the background of well characterized CHIKV strains LR2006 OPY1 and 37997. However, in the current study we demonstrate that introduction of the E1-A226V mutation into the background of an infectious clone derived from the Ag41855 strain (isolated in Uganda in 1982 does not significantly increase infectivity for Ae. albopictus. In order to elucidate the genetic determinants that affect CHIKV sensitivity to the E1-A226V mutation in Ae. albopictus, the genomes of the LR2006 OPY1 and Ag41855 strains were used for construction of chimeric viruses and viruses with a specific combination of point mutations at selected positions. Based upon the midgut infection rates of the derived viruses in Ae. albopictus and Ae. aegypti mosquitoes, a critical role of the mutations at positions E2-60 and E2-211 on vector infection was revealed. The E2-G60D mutation was an important determinant of CHIKV infectivity for both Ae. albopictus and Ae. aegypti, but only moderately modulated the effect of the E1-A226V mutation in Ae. albopictus. However, the effect of the E2-I211T mutation with respect to mosquito infections was much more specific, strongly modifying the effect of the E1-A226V mutation in Ae. albopictus. In contrast, CHIKV infectivity for Ae. aegypti was not influenced by the E2-1211T mutation. The occurrence of the E2-60G and E2-211I residues among CHIKV isolates was analyzed, revealing a high prevalence of E2-211I among strains belonging to the Eastern/Central/South African (ECSA clade. This suggests that the E2-211I might be important for adaptation of CHIKV to some particular conditions
Carlson, Jolene; O’Donnell, Vivian; Alfano, Marialexia; Velazquez Salinas, Lauro; Holinka, Lauren G.; Krug, Peter W.; Gladue, Douglas P.; Higgs, Stephen; Borca, Manuel V.
African swine fever (ASF) is a lethal hemorrhagic disease of swine caused by a double-stranded DNA virus, ASF virus (ASFV). There is no vaccine to prevent the disease and current control measures are limited to culling and restricting animal movement. Swine infected with attenuated strains are protected against challenge with a homologous virulent virus, but there is limited knowledge of the host immune mechanisms generating that protection. Swine infected with Pretoriuskop/96/4 (Pret4) virus develop a fatal severe disease, while a derivative strain lacking virulence-associated gene 9GL (Pret4Δ9GL virus) is completely attenuated. Swine infected with Pret4Δ9GL virus and challenged with the virulent parental virus at 7, 10, 14, 21, and 28 days post infection (dpi) showed a progressive acquisition of protection (from 40% at 7 dpi to 80% at 21 and 28 dpi). This animal model was used to associate the presence of host immune response (ASFV-specific antibody and interferon (IFN)-γ responses, or specific cytokine profiles) and protection against challenge. With the exception of ASFV-specific antibodies in survivors challenged at 21 and 28 dpi, no association between the parameters assessed and protection could be established. These results, encompassing data from 65 immunized swine, underscore the complexity of the system under study, suggesting that protection relies on the concurrence of different host immune mechanisms. PMID:27782090
Lulla, Valeria; Lulla, Aleksei; Wernike, Kerstin; Aebischer, Andrea; Beer, Martin
ABSTRACT African horse sickness virus (AHSV), an orbivirus in the Reoviridae family with nine different serotypes, causes devastating disease in equids. The virion particle is composed of seven proteins organized in three concentric layers, an outer layer made of VP2 and VP5, a middle layer made of VP7, and inner layer made of VP3 that encloses a replicase complex of VP1, VP4, and VP6 and a genome of 10 double-stranded RNA segments. In this study, we sought to develop highly efficacious candidate vaccines against all AHSV serotypes, taking into account not only immunogenic and safety properties but also virus productivity and stability parameters, which are essential criteria for vaccine candidates. To achieve this goal, we first established a highly efficient reverse genetics (RG) system for AHSV serotype 1 (AHSV1) and, subsequently, a VP6-defective AHSV1 strain in combination with in trans complementation of VP6. This was then used to generate defective particles of all nine serotypes, which required the exchange of two to five RNA segments to achieve equivalent titers of particles. All reassortant-defective viruses could be amplified and propagated to high titers in cells complemented with VP6 but were totally incompetent in any other cells. Furthermore, these replication-incompetent AHSV particles were demonstrated to be highly protective against homologous virulent virus challenges in type I interferon receptor (IFNAR)-knockout mice. Thus, these defective viruses have the potential to be used for the development of safe and stable vaccine candidates. The RG system also provides a powerful tool for the study of the role of individual AHSV proteins in virus assembly, morphogenesis, and pathogenesis. IMPORTANCE African horse sickness virus is transmitted by biting midges and causes African horse sickness in equids, with mortality reaching up to 95% in naive horses. Therefore, the development of efficient vaccines is extremely important due to major economic
Shea, B T; Bailey, R C
We have analyzed the growth allometry of external body proportions in Efe pygmies from Zaire and combined these data with values from the literature for comparable dimensions in adult pygmies and nonpygmies. We sequentially tested the hypotheses that adult proportion differences between 1) male vs. female Efe, and 2) pygmies vs. nonpygmies result from ontogenetic scaling, or the differential extension of common patterns of growth allometry. Results indicate an almost complete concordance of allometric trajectories for male and female Efe. These preliminary analyses also strongly suggest that adult nonpygmy Africans generally differ from pygmies in their terminal size and correlated allometric consequences, rather than in more fundamental alterations of underlying patterns of growth. Biacromial diameter emerges as the measurement most likely to depart from this general pattern. These results provide further evidence that shifts in systemic growth hormones yielding differences in terminal overall body size may be accompanied by global and coordinated allometric transformations. Certain proportion differences previously interpreted by some as specific evidence of primitive retention in pygmies in fact reflect simple growth allometric correlates of the derive rapid size decrease in these groups. Selected divergent body proportions characterizing adult pygmies, previously interpreted by some as independent evidence of climatic adaptation, also reflect such allometric correlates of ontogenetic scaling. We critically assess arguments that the small overall body size of pygmies was specifically selected for reasons of thermoregulatory efficiency, and consider an alternative or complementary scenario, based on selection for small size in order to reduce caloric requirements.
Dunbar, Angel S; Perry, Nicole B; Cavanaugh, Alyson M; Leerkes, Esther M
The current study aimed to identify parents' profiles of racial and emotion socialization practices, to determine if these profiles vary as a function of family income and young adult child gender, and to examine their links with young adults' emotional adaptation. Participants included 192 African American young adults (70% women) who ranged in age from 18 to 24 years (M = 19.44 years). Four maternal profiles emerged: cultural-supportive (high cultural socialization and supportive responses to children's negative emotions), moderate bias preparation (moderate preparation for bias, promotion of mistrust, and nonsupportive responses to negative emotions), high bias preparation (high preparation for bias, promotion of mistrust, and nonsupportive responses), and low engaged (low across racial and socialization constructs). Three paternal profiles emerged: multifaceted (moderate across racial and emotion socialization constructs), high bias preparation, and low engaged. Men were more likely to have mothers in the high bias preparation and to have fathers in the multifaceted or high bias preparation profiles. Individuals with higher income were more likely to have mothers in the cultural-supportive profile and to have fathers in the multifaceted profile. Young adults whose mothers fit the cultural-supportive profile or the moderate bias preparation profile had lower levels of depressive symptoms than young adults whose mothers fit the high bias preparation profile. PMID:25090149
Davies, Kalina T J; Bennett, Nigel C; Tsagkogeorga, Georgia; Rossiter, Stephen J; Faulkes, Christopher G
During their evolutionary radiation, mammals have colonized diverse habitats. Arguably the subterranean niche is the most inhospitable of these, characterized by reduced oxygen, elevated carbon dioxide, absence of light, scarcity of food, and a substrate that is energetically costly to burrow through. Of all lineages to have transitioned to a subterranean niche, African mole-rats are one of the most successful. Much of their ecological success can be attributed to a diet of plant storage organs, which has allowed them to colonize climatically varied habitats across sub-Saharan Africa, and has probably contributed to the evolution of their diverse social systems. Yet despite their many remarkable phenotypic specializations, little is known about molecular adaptations underlying these traits. To address this, we sequenced the transcriptomes of seven mole-rat taxa, including three solitary species, and combined new sequences with existing genomic data sets. Alignments of more than 13,000 protein-coding genes encompassed, for the first time, all six genera and the full spectrum of ecological and social variation in the clade. We detected positive selection within the mole-rat clade and along ancestral branches in approximately 700 genes including loci associated with tumorigenesis, aging, morphological development, and sociality. By combining these results with gene ontology annotation and protein-protein networks, we identified several clusters of functionally related genes. This family wide analysis of molecular evolution in mole-rats has identified a suite of positively selected genes, deepening our understanding of the extreme phenotypic traits exhibited by this group.
Xiao, Yinghong; Rouzine, Igor M; Bianco, Simone; Acevedo, Ashley; Goldstein, Elizabeth Faul; Farkov, Mikhail; Brodsky, Leonid; Andino, Raul
Mutation and recombination are central processes driving microbial evolution. A high mutation rate fuels adaptation but also generates deleterious mutations. Recombination between two different genomes may resolve this paradox, alleviating effects of clonal interference and purging deleterious mutations. Here we demonstrate that recombination significantly accelerates adaptation and evolution during acute virus infection. We identified a poliovirus recombination determinant within the virus polymerase, mutation of which reduces recombination rates without altering replication fidelity. By generating a panel of variants with distinct mutation rates and recombination ability, we demonstrate that recombination is essential to enrich the population in beneficial mutations and purge it from deleterious mutations. The concerted activities of mutation and recombination are key to virus spread and virulence in infected animals. These findings inform a mathematical model to demonstrate that poliovirus adapts most rapidly at an optimal mutation rate determined by the trade-off between selection and accumulation of detrimental mutations. PMID:27078068
Fahnøe, Ulrik; Orton, Richard; Höper, Dirk; Beer, Martin; Rasmussen, Thomas Bruun
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.
Donald K. Nichols
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.
Cortez, A B; Van Dop, C; Bailey, R C; Bersch, N; Scott, M; Golde, D W; Geffner, M E
To investigate IGF-I resistance in African Efe Pygmies, we examined clonal responsiveness to IGF-I in Epstein-Barr virus-transformed B-lymphocytes from three Efe Pygmies and three American control subjects. The Efe B-lymphoblasts did not increase clonal responsiveness when incubated with IGF-I (as high as 250 micrograms/liter) in contrast to the control B-lymphoblasts which showed a bimodal dose-response with a maximal stimulation of 50% above baseline. The proliferative response of Efe B-lymphoblasts was similar to that of control B-lymphoblasts when incubated with another growth factor, phorbol 12-myristate 13-acetate, which does not activate the IGF-I receptor. These findings indicate that Efe Pygmy B-lymphoblasts are resistant to IGF-I as measured by in vitro clonal proliferation assays. Coupled with our previous report of IGF-I unresponsiveness in Efe Pygmy HTLV-II-transformed T-lymphocytes, these data suggest that IGF-I resistance is generalized and may play a central role in the etiology of short stature in this population.
Zhou, X; Robinson, D J; Harrison, B D
Complete nucleotide sequences of the DNA-A-like molecules of three East African cassava mosaic virus (EACMV) isolates from Kenya (-K, 2801 nt) and Malawi (-MH and -MK, both 2804 nt) were determined. These sequences were compared with that published for a Tanzanian isolate (-T, 2801 nt) and the partial sequence of a third Malawian isolate. Intergenic region sequences of all isolates, and deduced amino acid sequences of their AC1 (Rep) proteins, each formed a tightly related cluster that was distinct from the comparable components of other begomoviruses. Other complementary-sense genes (AC2, AC3, AC4) differed between EACMV isolates in a way consistent with the accumulation of point mutations. In contrast, virus-sense genes (CP, AV2) of isolates -MH and -MK differed (substantially for AV2) from those of other EACMV isolates but somewhat resembled those of tomato yellow leaf curl virus-Israel, suggesting they had been acquired by recombination with an unidentified begomovirus.
Randriamparany, T; Kouakou, K V; Michaud, V; Fernández-Pinero, J; Gallardo, C; Le Potier, M-F; Rabenarivahiny, R; Couacy-Hymann, E; Raherimandimby, M; Albina, E
The performance of Whatman 3-MM filter papers for the collection, drying, shipment and long-term storage of blood at ambient temperature, and for the detection of African swine fever virus and antibodies was assessed. Conventional and real-time PCR, viral isolation and antibody detection by ELISA were performed on paired samples (blood/tissue versus dried-blood 3-MM filter papers) collected from experimentally infected pigs and from farm pigs in Madagascar and Côte d'Ivoire. 3-MM filter papers were used directly in the conventional and real-time PCR without previous extraction of nucleic acids. Tests that performed better with 3-MM filter papers were in descending order: virus isolation, real-time UPL PCR and conventional PCR. The analytical sensitivity of real-time UPL PCR on filter papers was similar to conventional testing (virus isolation or conventional PCR) on organs or blood. In addition, blood-dried filter papers were tested in ELISA for antibody detection and the observed sensitivity was very close to conventional detection on serum samples and gave comparable results. Filter papers were stored up to 9 months at 20-25°C and for 2 months at 37°C without significant loss of sensitivity for virus genome detection. All tests on 3-MM filter papers had 100% specificity compared to the gold standards. Whatman 3-MM filter papers have the advantage of being cheap and of preserving virus viability for future virus isolation and characterization. In this study, Whatman 3-MM filter papers proved to be a suitable support for the collection, storage and use of blood in remote areas of tropical countries without the need for a cold chain and thus provide new possibilities for antibody testing and virus isolation.
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.
Hernáez, Bruno; Guerra, Milagros; Salas, María L; Andrés, Germán
African swine fever virus (ASFV) is a nucleocytoplasmic large DNA virus (NCLDV) that causes a highly lethal disease in domestic pigs. As other NCLDVs, the extracellular form of ASFV possesses a multilayered structure consisting of a genome-containing nucleoid successively wrapped by a thick protein core shell, an inner lipid membrane, an icosahedral protein capsid and an outer lipid envelope. This structural complexity suggests an intricate mechanism of internalization in order to deliver the virus genome into the cytoplasm. By using flow cytometry in combination with pharmacological entry inhibitors, as well as fluorescence and electron microscopy approaches, we have dissected the entry and uncoating pathway used by ASFV to infect the macrophage, its natural host cell. We found that purified extracellular ASFV is internalized by both constitutive macropinocytosis and clathrin-mediated endocytosis. Once inside the cell, ASFV particles move from early endosomes or macropinosomes to late, multivesicular endosomes where they become uncoated. Virus uncoating requires acidic pH and involves the disruption of the outer membrane as well as of the protein capsid. As a consequence, the inner viral membrane becomes exposed and fuses with the limiting endosomal membrane to release the viral core into the cytosol. Interestingly, virus fusion is dependent on virus protein pE248R, a transmembrane polypeptide of the inner envelope that shares sequence similarity with some members of the poxviral entry/fusion complex. Collective evidence supports an entry model for ASFV that might also explain the uncoating of other multienveloped icosahedral NCLDVs. PMID:27110717
Anderson, E C; Hutchings, G H; Mukarati, N; Wilkinson, P J
Warthog (Phacochoerus aethiopicus), giant forest hog (Hylochoerus meinertzhageni) and bushpig (Potamochoerus porcus) are known to be susceptible to infection with African swine fever (ASF) virus. Little however, is known about the ecology of the disease in the bushpig. This study has shown that the bushpig remains viraemic for between 35 and 91 days following infection during which time it is able to infect the tick vector O. moubata. These ticks were able to transmit the disease to pigs. The virus persists in the lymphatic tissues for less than 34 weeks. Bushpigs infected with LIL 20/l virus but not VIC T90/l virus transmitted infection to in-contact pigs. Infected domestic pigs did not transmit the infection to in-contact bushpigs. ASF virus was able to replicate in in vitro cultures of bushpig leucocytes and endothelial cells. Recovered bushpigs could be reinfected with some strains of virus but not others. While it has been demonstrated that bushpigs remain carriers of ASFV following infection a complete understanding of their significance in the epidemiology of the disease awaits further investigations of their association with O. moubata. PMID:9659687
Akhtar, Nadeem; Pratt, Cornelius B.; Bo, Shan
Since 2006, the enrollment of African students in Chinese universities has been increasing steadily. A majority of the students have been recruited through the China Scholarship Council. Cast against that background of growth in the number of African students in Chinese universities, it is important that their educational experience in a country…
Shepherd, A J; Leman, P A; Swanepoel, R
Eleven species of small African wild mammals, laboratory rabbits, guinea pigs, and Syrian hamsters were infected with Crimean-Congo hemorrhagic fever (CCHF) virus. Low-titered viremia followed by development of antibody was observed in scrub hares (Lepus saxatilis), Cape ground squirrels (Xerus inauris), red veld rats (Aethomys chrysophilus), white tailed rats (Mystromys albicaudatus), bushveld gerbils (Tatera leucogaster), striped mice (Rhabdomys pumilio), and guinea pigs. The maximum viremic titer in 4 scrub hares was 10(1.7-4.2) 50% mouse lethal doses/ml. Viremia was detected in 1/17 infected laboratory rabbits. Antibody response was only detected in South African hedgehogs (Atelerix frontalis), highveld gerbils (T. brantsii), Namaqua gerbils (Desmodillus auricularis), 2 species of multimammate mouse (Mastomys natalensis and M. coucha), and Syrian hamsters. The results of the study indicate that a proportion of infected scrub hares develop CCHF viremia of an intensity shown in the Soviet Union to be sufficient for infection of feeding immature ixodid ticks, but that South African hedgehogs and wild rodents are unlikely to be of importance as maintenance hosts of the virus in southern Africa. PMID:2499205
van Sandwyk, James H D T; Bennett, Nigel C; Swanepoel, Robert; Bastos, Armanda D S
Encephalomyocarditis virus (EMCV) outbreaks are rare in southern Africa. Only two have been reported to date from South Africa, both coinciding with rodent irruptions. The first outbreak manifested as acute myocarditis in pigs in 1979, whilst the second, occurring from 1993 to 1994, was linked to the deaths of 64 free-ranging adult African elephants (Loxodonta africana). The P1 genome region, inclusive of the flanking leader (L) and 2A genes, of three South African isolates, one from swine and two from elephants, was characterised by PCR amplification and sequencing of up to 11 overlapping fragments. In addition to the resulting 3329 nucleotide dataset, the 3D region that is widely used in molecular epidemiology studies, was characterised, and three datasets (P1, VP1/3 and 3D), complemented with available homologous EMCV data, were compiled for analyses. Phylogenetic inferences revealed the near-identical elephant outbreak strains to be most closely related to a mengovirus from rhesus macaques (Macaca mulatta) in Uganda, differing from the latter by between 11% (3D) and 15% (VP3/1). The South African pig isolate differed by 4% (3D) and 11% (VP3/1) from available European and Asian pig virus sequences. This study confirms the presence of two genetically distinct EMCV lineages recovered from sporadic outbreaks in wild and domestic hosts in southern Africa, and provides valuable baseline data for future outbreak eventualities in the sub-region. PMID:23021643
Carthron, Dana; Bailey, Donald E.; Anderson, Ruth
To understand the challenges arising from the context within which diabetic African-American caregiving grandmothers self-manage their diabetes we used the Adaptive Leadership Framework. Additionally, challenges to retaining this population in a longitudinal study were examined. In this exploratory, longitudinal, qualitative pilot study, data were collected at five time-points over 18 months. We coded the data using content analysis and conducted the within-case and cross-case analyses using data matrices. Lack of awareness of available resources, represented a technical challenge within the life context of these grandmothers and the remaining three themes: family upheaval; priority setting (with subthemes of difficulty meeting basic needs and competing demands); and self-silencing and self-sacrifice represented adaptive challenges. The context of African-American grandmothers’ lives created primarily adaptive challenges that were complex and without immediate solutions. Research is needed to develop culturally and contextually appropriate interventions to help this vulnerable group develop capacity for adaptive work. PMID:27064619
Pretorius, Alri; Van Kleef, Mirinda; Van Wyngaardt, Wouter; Heath, Jeanette
African horsesickness (AHS) is an infectious but noncontagious viral disease affecting all species of Equidae. The recall immune response of AHSV naïve horses immunised with an attenuated African horsesickness virus serotype 4 (AHSV4) was characterised using immune assays including ELISPOT, real-time PCR (qPCR) and flow cytometry. The recall immune response detected in PBMC isolated from three inoculated horses showed an upregulation of circulating B lymphocytes that correlated with elevated IL-4 mRNA expression indicative of humoral immunity, but reduced frequency of CD4⁺ cells. In addition to the expected antibody response, an increase in CD8⁺ cells was also detected. Although these CD8⁺ cells may be CTL, the role of these cells in immunity against AHSV still has to be determined.
Full Text Available Aim: To collect Infectious bursal disease virus (IBDV infected bursae based on postmortem findings of clinical samples followed by molecular confirmation and adaptation on chicken embryo fibroblast cell. Material and Methods: Enlarged bursae were processed to make 10% suspension in phosphate buffer saline and were used for viral RNA isolation to carryout VP2 gene fragment amplification using RT-PCR technique. Suspension was also used for adaptation of IBDV on chicken embryo fibroblast cells prepared from 11 day old chicken embryos. Infective titer of virus was calculated using Reed and Muench method. Results: Fifteen dead birds suspected of IBD infection were collected from different local poultry farms of Jabalpur (Madhya Pradesh. After post-mortem, twelve enlarged bursae sample were used for total RNA isolation which was used for amplification of VP2 gene. Out of twelve, eleven were found positive for VP2 gene amplification. Virological characterization of PCR positive sample was done on chicken embryo fibroblast cell culture and various cytopathic effects like rounding of cells, cellular detachment and vacuolation were shown by five IBD field isolates after 48 hours on 4th passage. TCID50 per ml of the adapted virus on 4th passage at 48 hours after infection was 1.46 x 107 . Conclusion: VP2 gene amplification using RT-PCR technique is a specific target for IBDV detection. Passaging of highly virulent IBDV field isolates in cell culture leads to attenuation of virus which can be exploited as a cell culture adapted vaccine candidate.
Infection of pregnant cows with noncytopathic (ncp) BVDV induces rapid innate and adaptive immune responses resulting in clearance of the virus in less than 3 weeks. Seven to 14 days after inoculation of the cow, ncpBVDV crosses the placenta and induces a fetal viremia. Establishment of persistent ...
Judith M Fonville
Full Text Available Adaptation of zoonotic influenza viruses towards efficient human-to-human transmissibility is a substantial public health concern. The recently emerged A/H7N9 influenza viruses in China provide an opportunity for quantitative studies of host-adaptation, as human-adaptive substitutions in the PB2 gene of the virus have been found in all sequenced human strains, while these substitutions have not been detected in any non-human A/H7N9 sequences. Given the currently available information, this observation suggests that the human-adaptive PB2 substitution might confer a fitness advantage to the virus in these human hosts that allows it to rise to proportions detectable by consensus sequencing over the course of a single human infection. We use a mathematical model of within-host virus evolution to estimate the fitness advantage required for a substitution to reach predominance in a single infection as a function of the duration of infection and the fraction of mutant present in the virus population that initially infects a human. The modeling results provide an estimate of the lower bound for the fitness advantage of this adaptive substitution in the currently sequenced A/H7N9 viruses. This framework can be more generally used to quantitatively estimate fitness advantages of adaptive substitutions based on the within-host prevalence of mutations. Such estimates are critical for models of cross-species transmission and host-adaptation of influenza virus infections.
Suneth S. Perera
Full Text Available The first line of defence of the innate immune system functions by recognizing highly conserved sets of molecular structures specific to the microbes, termed pathogen-associated molecular patterns, or PAMPs via the germ line-encoded receptors Pattern-Recognition Receptors (PRRs. In addition to the innate immune system, the vertebrates have also evolved a second line of defence termed adaptive immune system, which uses a diverse set of somatically rearranged receptors T-Cell Receptors (TCRs and B Cell Receptors (BCRs, which have the inherent ability to effectively recognise diverse antigens. The innate and adaptive immune systems are functionally tied in with the intrinsic immunity, which comprises of endogenous antiviral factors. Thus, this effective response to diverse microbial infections, including HIV, requires a coordinated interaction at several functional levels between innate, adaptive and intrinsic immune systems. This review provides a snapshot of roles played by the innate, adaptive and the intrinsic immune systems during HIV-infection, along with discussing recent developments highlighting the genomic basis of these responses and their regulation by micro-RNA (miRNAs.
Berrie, L C; Rybicki, E P; Rey, M E
Complete nucleotide sequences of the DNA-A (2800 nt) and DNA-B (2760 nt) components of a novel cassava-infecting begomovirus, South African cassava mosaic virus (SACMV), were determined and compared with various New World and Old World begomoviruses. SACMV is most closely related to East African cassava mosaic virus (EACMV) in both its DNA-A (85% with EACMV-MH and -MK) and -B (90% with EACMV-UG2-Mld and EACMV-UG3-Svr) components; however, percentage sequence similarities of less than 90% in the DNA-A component allowed SACMV to be considered a distinct virus. One significant recombination event spanning the entire AC4 open reading frame was identified; however, there was no evidence of recombination in the DNA-B component. Infectivity of the cloned SACMV genome was demonstrated by successful agroinoculation of cassava and three other plant species (Phaseolus vulgaris, Malva parviflora and Nicotiana benthamiana). This is the first description of successful infection of cassava with a geminivirus using Agrobacterium tumefaciens.
Full Text Available Psittacine beak and feather disease (PBFD is a common viral disease of wild and captive psittacine birds characterized by symmetric feather loss and beak deformities. The causative agent, beak and feather disease virus (BFDV, is a small, circular single-stranded DNA virus that belongs to the genus Circovirus. BFDV can be detected by PCR or the use of haemagglutination (HA and haemagglutination inhibition (HI assays that detect antigen and antibodies respectively. Erythrocytes from a limited number of psittacine species of Australian origin can be used in these tests. In South Africa, the high cost of these birds makes them difficult to obtain for experimental purposes. Investigation into the use of erythrocytes from African Grey parrots and Brown-headed parrots yielded positive results showing the haemagglutinating activity of their erythrocytes with purified BFDV obtained from confirmed clinical cases of the disease. The HA activity was further confirmed by the demonstration of HI using BFDV antiserum from three different African Grey parrots previously exposed to the virus and not showing clinical signs of the disease.
Konstantin A Tsetsarkin
Full Text Available The adaptation of Chikungunya virus (CHIKV to a new vector, the Aedes albopictus mosquito, is a major factor contributing to its ongoing re-emergence in a series of large-scale epidemics of arthritic disease in many parts of the world since 2004. Although the initial step of CHIKV adaptation to A. albopictus was determined to involve an A226V amino acid substitution in the E1 envelope glycoprotein that first arose in 2005, little attention has been paid to subsequent CHIKV evolution after this adaptive mutation was convergently selected in several geographic locations. To determine whether selection of second-step adaptive mutations in CHIKV or other arthropod-borne viruses occurs in nature, we tested the effect of an additional envelope glycoprotein amino acid change identified in Kerala, India in 2009. This substitution, E2-L210Q, caused a significant increase in the ability of CHIKV to develop a disseminated infection in A. albopictus, but had no effect on CHIKV fitness in the alternative mosquito vector, A. aegypti, or in vertebrate cell lines. Using infectious viruses or virus-like replicon particles expressing the E2-210Q and E2-210L residues, we determined that E2-L210Q acts primarily at the level of infection of A. albopictus midgut epithelial cells. In addition, we observed that the initial adaptive substitution, E1-A226V, had a significantly stronger effect on CHIKV fitness in A. albopictus than E2-L210Q, thus explaining the observed time differences required for selective sweeps of these mutations in nature. These results indicate that the continuous CHIKV circulation in an A. albopictus-human cycle since 2005 has resulted in the selection of an additional, second-step mutation that may facilitate even more efficient virus circulation and persistence in endemic areas, further increasing the risk of more severe and expanded CHIK epidemics.
Tsetsarkin, Konstantin A; Weaver, Scott C
The adaptation of Chikungunya virus (CHIKV) to a new vector, the Aedes albopictus mosquito, is a major factor contributing to its ongoing re-emergence in a series of large-scale epidemics of arthritic disease in many parts of the world since 2004. Although the initial step of CHIKV adaptation to A. albopictus was determined to involve an A226V amino acid substitution in the E1 envelope glycoprotein that first arose in 2005, little attention has been paid to subsequent CHIKV evolution after this adaptive mutation was convergently selected in several geographic locations. To determine whether selection of second-step adaptive mutations in CHIKV or other arthropod-borne viruses occurs in nature, we tested the effect of an additional envelope glycoprotein amino acid change identified in Kerala, India in 2009. This substitution, E2-L210Q, caused a significant increase in the ability of CHIKV to develop a disseminated infection in A. albopictus, but had no effect on CHIKV fitness in the alternative mosquito vector, A. aegypti, or in vertebrate cell lines. Using infectious viruses or virus-like replicon particles expressing the E2-210Q and E2-210L residues, we determined that E2-L210Q acts primarily at the level of infection of A. albopictus midgut epithelial cells. In addition, we observed that the initial adaptive substitution, E1-A226V, had a significantly stronger effect on CHIKV fitness in A. albopictus than E2-L210Q, thus explaining the observed time differences required for selective sweeps of these mutations in nature. These results indicate that the continuous CHIKV circulation in an A. albopictus-human cycle since 2005 has resulted in the selection of an additional, second-step mutation that may facilitate even more efficient virus circulation and persistence in endemic areas, further increasing the risk of more severe and expanded CHIK epidemics. PMID:22174678
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
Full Text Available Anne Plauzolles,1 Michaela Lucas,2,3 Silvana Gaudieri41Centre for Forensic Science, 2School of Medicine and Pharmacology, Harry Perkins Institute, 3School of Pathology and Laboratory Medicine, 4School of Anatomy, Physiology and Human Biology, University of Western Australia, Perth, WA, AustraliaAbstract: Genetic and cellular studies have shown that the host's innate and adaptive immune responses are an important correlate of viral infection outcome. The features of the host's immune response (host resistance reflect the coevolution between hosts and pathogens that has occurred over millennia, and that has also resulted in a number of strategies developed by viruses to improve fitness and survival within the host (viral adaptation. In this review, we discuss viral adaptation to host immune pressure via protein–protein interactions and sequence-specific mutations. Specifically, we will present the “state of play” on viral escape mutations to host T-cell responses in the context of the hepatitis C virus, and their influence on infection outcome.Keywords: hepatitis C virus, viral adaptation, immune escape, adaptive immune response
Martin-Alonso, Aarón; Martin-Carrillo, Natalia; Garcia-Livia, Katherine; Valladares, Basilio; Foronda, Pilar
Until the beginning of this decade, the genetic characterization of rabbit haemorrhagic disease virus (RHDV) from Iberian Peninsula had revealed the existence of two genogroups, G1 and sporadically G6. In 2010, the new emerging rabbit haemorrhagic disease variant, RHDV2 or RHDVb, was described in France, from where it has rapidly spread throughout Europe, including Iberian Peninsula countries. Nevertheless, although cases of rabbit haemorrhagic disease (RHD) have been reported in the Canary Islands, a Spanish archipelago located 100km off the coast of Morocco, no genetic characterization of RHDV had been carried out. Consequently, in order to identify the circulating RHDV strains in this archipelago, liver samples of six farm rabbits and fifteen wild rabbits were collected from several areas of the largest island, Tenerife, and analyzed for the presence of RHDV by antigen capture double antibody sandwich ELISA. In case of positive ELISA result, we amplified and sequenced two fragments of the vp60 gene, which were concatenated for phylogenetic purposes. The sequences analysis revealed the presence of RHDV2 in both farm and wild rabbits from several areas of Tenerife. This result constitutes the first finding of RHDV2 in the Canary Islands. These RHDV2 strains found in Tenerife shared two exclusive SNPs that have not been observed in the rest of RHDV2 strains. The identification of RHDV2 and the absence of classic RHDV strains in this study suggest that RHDV2 may be replacing classic strains in Tenerife, as has been also proposed in Iberian Peninsula, France and Azores. Given the proximity of the Canary Islands to the African continent, this result should raise awareness about a possible dispersal of RHDV2 from the Canary Islands to the North of Africa.
Bárbara V Lago
Full Text Available Brazil is a country of low hepatitis B virus (HBV endemicity in which the genotype A of HBV (HBV/A is the most prevalent. The complete nucleotide sequences of 26 HBV/A isolates, originating from eight Brazilian states, were determined. All were adw2. Twenty-three belonged to subgenotype A1 and three to A2. By phylogenetic analysis, it was shown that all the 23 HBV/A1 isolates clustered together with isolates from Bangladesh, India, Japan, Nepal, the Philippines and United Arab Emirates, but not with those of Congo, Kenya, Malawi, Rwanda, South Africa, Tanzania, Uganda and Zimbabwe. Four amino acid residues in the polymerase (His138 in the terminal protein domain, Pro18 and His90 in the spacer, and Ser109 in the reverse transcriptase, and one (Phe17 in the precore region, predominated in Latin American and Asian HBV/A1 isolates, but were rarely encountered in African isolates, with the exception of those from Somalia. Specific variations of two adjacent amino acids in the C-terminal domain of the HBx protein, namely Ala146 and Pro147, were found in all the Brazilian, but rarely in the other HBV/A1 isolates. By Bayesian analysis, the existence of an 'Asian-American' clade within subgenotype A1 was supported by a posterior probability value of 0.996. The close relatedness of the Brazilian, Asian and Somalian isolates suggests that the HBV/A1 strains predominant in Brazil did not originate from the five million slaves who were imported from Central and Western Africa from 1551 to 1840, but rather from the 300-400,000 captives forcibly removed from southeast Africa at the middle of the 19th century.
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.
Coat proteins (CPs) of geminiviruses are multifunctional proteins. Using transient expression experiments, we have recently identified putative sequence motifs of African cassava mosaic virus (ACMV) CP involved in nuclear import (NLS) and export (NES) (Virology 286 (2001) 373). Here, we report on the effect of corresponding deletion mutants in the context of infecting viruses. Since NLS and NES may overlap with DNA binding and multimerisation domains, we have investigated their effect on viral infection, particularly, on particle formation. All deletion mutants were infectious in Nicotiana benthamiana when co-inoculated with DNA B, but poorly sap-transmissible. Some of the mutants showed reduced levels of viral single-stranded DNA (ssDNA), whereas the amount of double-stranded DNA (dsDNA) was not greatly affected. None of these CP mutants was able to produce stable virus particles. In contrast, viruses with CP fused to Flag epitopes at the N- or C-terminus (CP:Flag or Flag:CP) were readily sap-transmissible and formed amorphous nucleoprotein particles but only few geminate structures. The relevance of the identified sequences in replicating viruses with reference to nuclear import and export as well as to particle stability and DNA binding is discussed
Shamil R Sunyaev
Full Text Available PML is a progressive and mostly fatal demyelinating disease caused by JC virus infection and destruction of infected oligodendrocytes in multiple brain foci of susceptible individuals. While JC virus is highly prevalent in the human population, PML is a rare disease that exclusively afflicts only a small percentage of immunocompromised individuals including those affected by HIV (AIDS or immunosuppressive drugs. Viral- and/or host-specific factors, and not simply immune status, must be at play to account for the very large discrepancy between viral prevalence and low disease incidence. Here, we show that several amino acids on the surface of the JC virus capsid protein VP1 display accelerated evolution in viral sequences isolated from PML patients but not in sequences isolated from healthy subjects. We provide strong evidence that at least some of these mutations are involved in binding of sialic acid, a known receptor for the JC virus. Using statistical methods of molecular evolution, we performed a comprehensive analysis of JC virus VP1 sequences isolated from 55 PML patients and 253 sequences isolated from the urine of healthy individuals and found that a subset of amino acids found exclusively among PML VP1 sequences is acquired via adaptive evolution. By modeling of the 3-D structure of the JC virus capsid, we showed that these residues are located within the sialic acid binding site, a JC virus receptor for cell infection. Finally, we go on to demonstrate the involvement of some of these sites in receptor binding by demonstrating a profound reduction in hemagglutination properties of viral-like particles made of the VP1 protein carrying these mutations. Collectively, these results suggest that a more virulent PML causing phenotype of JC virus is acquired via adaptive evolution that changes viral specificity for its cellular receptor(s.
Goldstein, Simoy; Brown, Charles R.; Ourmanov, Ilnour; Pandrea, Ivona; Buckler-White, Alicia; Erb, Christopher; Nandi, Jayashree S; Foster, Gabriel J.; Autissier, Patrick; Schmitz, Jörn E.; Hirsch, Vanessa M.
The simian immunodeficiency viruses (SIV) naturally infect a wide range of African primates, including African green monkeys (AGM). Despite moderate to high levels of plasma viremia in naturally infected AGM, infection is not associated with immunodeficiency. We recently reported that SIVagmVer90 isolated from a naturally infected vervet AGM induced AIDS following experimental inoculation of pigtailed macaques. The goal of the present study was to evaluate the replication of this isolate in t...
Madarame, Hiroo; Ogihara, Kikumi; Kimura, Moe; Nagai, Makoto; Omatsu, Tsutomu; Ochiai, Hideharu; Mizutani, Tetsyuya
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. PMID:25129384
Mora, J; Waelbroeck, H
We argue that the phenomenon of symmetry breaking in genetics can enhance the adaptability of a species to changes in the environment. In the case of a virus, the claim is that the codon bias in the neutralization epitope improves the virus' ability to generate mutants that evade the induced immune response. We support our claim with a simple ``toy model'' of a viral epitope evolving in competition with the immune system. The effective selective advantage of a higher mutability leads to a dominance of codons that favour non-synonymous mutations. The results in this paper suggest the possibility of emergence of an algorithmic language in more complicated systems.
Li, Xingguang; Zai, Junjie; Liu, Haizhou; Feng, Yi; Li, Fan; Wei, Jing; Zou, Sen; Yuan, Zhiming; Shao, Yiming
Following its immergence in December 2013, the recent Zaire Ebola virus (EBOV) outbreak in West Africa has spread and persisted for more than two years, making it the largest EBOV epidemic in both scale and geographical region to date. In this study, a total of 726 glycoprotein (GP) gene sequences of the EBOV full-length genome obtained from West Africa from the 2014 outbreak, combined with 30 from earlier outbreaks between 1976 and 2008 were used to investigate the genetic divergence, evolutionary history, population dynamics, and selection pressure of EBOV among distinct epidemic waves. Results from our dataset showed that no non-synonymous substitutions occurred on the GP gene coding sequences of EBOV that were likely to have affected protein structure or function in any way. Furthermore, the significantly different dN/dS ratios observed between the 2014 West African outbreak and earlier outbreaks were more likely due to the confounding presence of segregating polymorphisms. Our results highlight no robust evidence that the 2014 EBOV outbreak is fast-evolving and adapting to humans. Therefore, the unprecedented nature of the 2014 EBOV outbreak might be more likely related to non-virological elements, such as environmental and sociological factors. PMID:27767073
Li, Yan; Yang, Zexiao
Classical swine fever virus (CSFV) is the pathogen that causes a highly infectious disease of pigs and has led to disastrous losses to pig farms and related industries. The RNA-dependent RNA polymerase (RdRp) NS5B is a central component of the replicase complex (RC) in some single-stranded RNA viruses, including CSFV. On the basis of genetic variation, the CSFV RdRps could be clearly divided into 2 major groups and a minor group, which is consistent with the phylogenetic relationships and virulence diversification of the CSFV isolates. However, the adaptive signature underlying such an evolutionary profile of the polymerase and the virus is still an interesting open question. We analyzed the evolutionary trajectory of the CSFV RdRps over different timescales to evaluate the potential adaptation. We found that adaptive selection has driven the diversification of the RdRps between, but not within, CSFV major groups. Further, the major adaptive divergence-related sites are located in the surfaces relevant to the interaction with other component(s) of RC and the entrance and exit of the template-binding channel. These results might shed some light on the nature of the RdRp in virulence diversification of CSFV groups.
Li, Yan; Yang, Zexiao
Classical swine fever virus (CSFV) is the pathogen that causes a highly infectious disease of pigs and has led to disastrous losses to pig farms and related industries. The RNA-dependent RNA polymerase (RdRp) NS5B is a central component of the replicase complex (RC) in some single-stranded RNA viruses, including CSFV. On the basis of genetic variation, the CSFV RdRps could be clearly divided into 2 major groups and a minor group, which is consistent with the phylogenetic relationships and virulence diversification of the CSFV isolates. However, the adaptive signature underlying such an evolutionary profile of the polymerase and the virus is still an interesting open question. We analyzed the evolutionary trajectory of the CSFV RdRps over different timescales to evaluate the potential adaptation. We found that adaptive selection has driven the diversification of the RdRps between, but not within, CSFV major groups. Further, the major adaptive divergence-related sites are located in the surfaces relevant to the interaction with other component(s) of RC and the entrance and exit of the template-binding channel. These results might shed some light on the nature of the RdRp in virulence diversification of CSFV groups. PMID:26485449
Gorter, Florien A; Scanlan, Pauline D; Buckling, Angus
Parasite local adaptation, the greater performance of parasites on their local compared with foreign hosts, has important consequences for the maintenance of diversity and epidemiology. While the abiotic environment may significantly affect local adaptation, most studies to date have failed either to incorporate the effects of the abiotic environment, or to separate them from those of the biotic environment. Here, we tease apart biotic and abiotic components of local adaptation using the bacterium Pseudomonas fluorescens and its viral parasite bacteriophage Φ2. We coevolved replicate populations of bacteria and phages at three different temperatures, and determined their performance against coevolutionary partners from the same and different temperatures. Crucially, we measured performance at different assay temperatures, which allowed us to disentangle adaptation to biotic and abiotic habitat components. Our results show that bacteria and phages are more resistant and infectious, respectively, at the temperature at which they previously coevolved, confirming that local adaptation to abiotic conditions can play a crucial role in determining parasite infectivity and host resistance. Our work underlines the need to assess host-parasite interactions across multiple relevant abiotic environments, and suggests that microbial adaption to local temperatures can create ecological barriers to dispersal across temperature gradients.
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.
Johan T. Burger
Full Text Available The complete sequences of RNA1, RNA2 and satellite RNA have been determined for a South African isolate of Grapevine fanleaf virus (GFLV-SACH44. The two RNAs of GFLV-SACH44 are 7,341 nucleotides (nt and 3,816 nt in length, respectively, and its satellite RNA (satRNA is 1,104 nt in length, all excluding the poly(A tail. Multiple sequence alignment of these sequences showed that GFLV-SACH44 RNA1 and RNA2 were the closest to the South African isolate, GFLV-SAPCS3 (98.2% and 98.6% nt identity, respectively, followed by the French isolate, GFLV-F13 (87.3% and 90.1% nt identity, respectively. Interestingly, the GFLV-SACH44 satRNA is more similar to three Arabis mosaic virus satRNAs (85%–87.4% nt identity than to the satRNA of GFLV-F13 (81.8% nt identity and was most distantly related to the satRNA of GFLV-R2 (71.0% nt identity. Full-length infectious clones of GFLV-SACH44 satRNA were constructed. The infectivity of the clones was tested with three nepovirus isolates, GFLV-NW, Arabis mosaic virus (ArMV-NW and GFLV-SAPCS3. The clones were mechanically inoculated in Chenopodium quinoa and were infectious when co-inoculated with the two GFLV helper viruses, but not when co-inoculated with ArMV-NW.
Yang, Jingjie; Leen, Eoin N.; Maree, Francois F.
The replication of foot-and-mouth disease virus (FMDV) is dependent on the virus-encoded 3C protease (3Cpro). As in other picornaviruses, 3Cpro performs most of the proteolytic processing of the polyprotein expressed from the large open reading frame in the RNA genome of the virus. Previous work revealed that the 3Cpro from serotype A—one of the seven serotypes of FMDV—adopts a trypsin-like fold. On the basis of capsid sequence comparisons the FMDV serotypes are grouped into two phylogenetic clusters, with O, A, C, and Asia 1 in one, and the three Southern African Territories serotypes, (SAT-1, SAT-2 and SAT-3) in another, a grouping pattern that is broadly, but not rigidly, reflected in 3Cpro amino acid sequences. We report here the cloning, expression and purification of 3C proteases from four SAT serotype viruses (SAT2/GHA/8/91, SAT1/NIG/5/81, SAT1/UGA/1/97, and SAT2/ZIM/7/83) and the crystal structure at 3.2 Å resolution of 3Cpro from SAT2/GHA/8/91. PMID:27168976
Yang, Jingjie; Leen, Eoin N; Maree, Francois F; Curry, Stephen
The replication of foot-and-mouth disease virus (FMDV) is dependent on the virus-encoded 3C protease (3C(pro)). As in other picornaviruses, 3C(pro) performs most of the proteolytic processing of the polyprotein expressed from the large open reading frame in the RNA genome of the virus. Previous work revealed that the 3C(pro) from serotype A-one of the seven serotypes of FMDV-adopts a trypsin-like fold. On the basis of capsid sequence comparisons the FMDV serotypes are grouped into two phylogenetic clusters, with O, A, C, and Asia 1 in one, and the three Southern African Territories serotypes, (SAT-1, SAT-2 and SAT-3) in another, a grouping pattern that is broadly, but not rigidly, reflected in 3C(pro) amino acid sequences. We report here the cloning, expression and purification of 3C proteases from four SAT serotype viruses (SAT2/GHA/8/91, SAT1/NIG/5/81, SAT1/UGA/1/97, and SAT2/ZIM/7/83) and the crystal structure at 3.2 Å resolution of 3C(pro) from SAT2/GHA/8/91. PMID:27168976
Shen, Shu; Shi, Junming; Wang, Jun; Tang, Shuang; Wang, Hualin; Hu, Zhihong; Deng, Fei
Recent outbreaks of Zika virus (ZIKV) infections in Oceania's islands and the Americas were characterized by high numbers of cases and the spread of the virus to new areas. To better understand the origin of ZIKV, its epidemic history was reviewed. Although the available records and information are limited, two major genetic lineages of ZIKV were identified in previous studies. However, in this study, three lineages were identified based on a phylogenetic analysis of all virus sequences from GenBank, including those of the envelope protein (E) and non-structural protein 5 (NS5) coding regions. The spatial and temporal distributions of the three identified ZIKV lineages and the recombination events and mechanisms underlying their divergence and evolution were further elaborated. The potential migration pathway of ZIKV was also characterized. Our findings revealed the central roles of two African countries, Senegal and Cote d'Ivoire, in ZIKV evolution and genotypic divergence. Furthermore, our results suggested that the outbreaks in Asia and the Pacific islands originated from Africa. The results provide insights into the geographic origins of ZIKV outbreaks and the spread of the virus, and also contribute to a better understanding of ZIKV evolution, which is important for the prevention and control of ZIKV infections.
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.
Gert J. Venter
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.
Venter, Gert J; Labuschagne, Karien; Majatladi, Daphney; Boikanyo, Solomon N B; Lourens, Carina; Ebersohn, Karen; Venter, Estelle H
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. PMID:25686125
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...
Arafa, A; Suarez, D; Kholosy, S G; Hassan, M K; Nasef, S; Selim, A; Dauphin, G; Kim, M; Yilma, J; Swayne, D; Aly, M M
Highly pathogenic avian influenza (HPAI) virus of the H5N1 subtype was first diagnosed in poultry in Egypt in 2006, and since then the disease became enzootic in poultry throughout the country, affecting the poultry industry and village poultry as well as infecting humans. Vaccination has been used as a part of the control strategy to help to control the disease. Epidemiological data with sequence analysis of H5N1 viruses is important to link the mechanism of virus evolution in Egypt. This study describes the evolutionary pattern of Egyptian H5N1 viruses based on molecular characterization for the isolates collected from commercial poultry farms and village poultry from 2006 to 2011. Genetic analysis of the hemagglutinin (HA) gene was done by sequencing of the full-length H5 gene. The epidemiological pattern of disease outbreaks in Egyptian poultry farms seems to be seasonal with no specific geographic distribution across the country. The molecular epidemiological data revealed that there are two major groups of viruses: the classic group of subclade 2.2.1 and a variant group of 22.214.171.124. The classic group is prevailing mainly in village poultry and had fewer mutations compared to the originally introduced virus in 2006. Since 2009, this group has started to be transmitted back to commercial sectors. The variant group emerged by late 2007, was prevalent mainly in vaccinated commercial poultry, mutated continuously at a higher rate until 2010, and started to decline in 2011. Genetic analysis of the neuraminidase (NA) gene and the other six internal genes indicates a grouping of the Egyptian viruses similar to that obtained using the HA gene, with no obvious reassortments. The results of this study indicate that HPAI-H5N1 viruses are progressively evolving and adapting in Egypt and continue to acquire new mutations every season. PMID:22760662
Hadsbjerg, Johanne; Friis, Martin Barfred; Fahnøe, Ulrik;
of the subdomain IIIf of the internal ribosome entry site (IRES) that directs the initiation of protein synthesis. Rescued viruses were inoculated into pigs. The rescued vPader10 virus, without modifications in the IRES, induced clinical disease in pigs that was very similar to that observed previously...... 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...
Verdier, M; Denis, F; Leonard, G; Sangare, A; Patillaud, S; Prince-David, M; Essex, M.
The effectiveness of four screening tests for detecting antibody to human T-cell leukemia virus type I (HTLV-I) was determined by using 2,700 African serum specimens. The tests studied were indirect immunofluorescence, particle agglutination from Fujirebio, and two enzyme immunoassays, one from Abbott Laboratories that used virus lysate from HUT 102 cells and the other from Cambridge BioScience Corp. that used an env recombinant protein. Positive and doubtful sera were confirmed by Western im...
Full Text Available The frequency of change in the selective pressures is one of the main factors driving evolution. It is generally accepted that constant environments select specialist organisms whereas changing environments favour generalists. The particular outcome achieved in either case also depends on the relative strength of the selective pressures and on the fitness costs of mutations across environments. RNA viruses are characterized by their high genetic diversity, which provides fast adaptation to environmental changes and helps them evade most antiviral treatments. Therefore, the study of the adaptive possibilities of RNA viruses is highly relevant for both basic and applied research. In this study we have evolved an RNA virus, the bacteriophage Qβ, under three different temperatures that either were kept constant or alternated periodically. The populations obtained were analyzed at the phenotypic and the genotypic level to characterize the evolutionary process followed by the virus in each case and the amount of convergent genetic changes attained. Finally, we also investigated the influence of the pre-existent genetic diversity on adaptation to high temperature. The main conclusions that arise from our results are: i under periodically changing temperature conditions, evolution of bacteriophage Qβ is driven by the most stringent selective pressure, ii there is a high degree of evolutionary convergence between replicated populations and also among populations evolved at different temperatures, iii there are mutations specific of a particular condition, and iv adaptation to high temperatures in populations differing in their pre-existent genetic diversity takes place through the selection of a common set of mutations.
Chiam, Chun Wei; Chan, Yoke Fun; Ong, Kien Chai; Wong, Kum Thong; Sam, I-Ching
Chikungunya virus (CHIKV), an alphavirus of the family Togaviridae, causes fever, polyarthritis and rash. There are three genotypes: West African, Asian and East/Central/South African (ECSA). The latter two genotypes have caused global outbreaks in recent years. Recent ECSA CHIKV outbreaks have been associated with severe neurological disease, but it is not known if different CHIKV genotypes are associated with different neurovirulence. In this study, the neurovirulence of Asian (MY/06/37348) and ECSA (MY/08/065) strains of CHIKV isolated in Malaysia were compared. Intracerebral inoculation of either virus into suckling mice was followed by virus titration, histopathology and gene expression analysis of the harvested brains. Both strains of CHIKV replicated similarly, yet mice infected with MY/06/37348 showed higher mortality. Histopathology findings showed that both CHIKV strains spread within the brain (where CHIKV antigen was localized to astrocytes and neurons) and beyond to skeletal muscle. In MY/06/37348-infected mice, apoptosis, which is associated with neurovirulence in alphaviruses, was observed earlier in brains. Comparison of gene expression showed that a pro-apoptotic gene (eIF2αK2) was upregulated at higher levels in MY/06/37348-infected mice, while genes involved in anti-apoptosis (BIRC3), antiviral responses and central nervous system protection (including CD40, IL-10RA, MyD88 and PYCARD) were upregulated more highly in MY/08/065-infected mice. In conclusion, the higher mortality observed following MY/06/37348 infection in mice is due not to higher viral replication in the brain, but to differentially expressed genes involved in host immune responses. These findings may help to identify therapeutic strategies and biomarkers for neurological CHIKV infections.
AN Wen-qi; LIU Xiu-fan; WANG Xi-liang; YANG Peng-hui; DUAN Yue-qiang; LUO De-yan; TANG Chong; JIA Wei-hong; XING Li; SHI Xin-fu; ZHANG Yu-jing
Background H3N2 subtype influenza A viruses have been identified in humans worldwide, raising concerns about their pandemic potential and prompting the development of candidate vaccines to protect humans against this subtype of influenza A virus. The aim of this study was to establish a system for rescuing of a cold-adapted high-yielding H3N2 subtype human influenza virus by reverse genetics. Methods In order to generate better and safer vaccine candidate viruses, a cold-adapted high yielding reassortant H3N2 influenza A virus was genetically constructed by reverse genetics and was designated as rgAA-H3N2. The rgAA-H3N2 virus contained HA and NA genes from an epidemic strain A/Wisconsin/67/2005 (H3N2) in a background of internal genes derived from the master donor viruses (MDV), cold-adapted (ca), temperature sensitive (te), live attenuated influenza virus strain A/Ann Arbor/6/60 (MDV-A). Results In this presentation, the virus HA titer of rgAA-H3N2 in the allantoic fluid from infected embryonated eggs was as high as 1:1024. A fluorescent focus assay (FFU) was performed 24-36 hours post-infection using a specific antibody and bright staining was used for determining the virus titer. The allantoic fluid containing the recovered influenza virus was analyzed in a hemagglutination inhibition (HI) test and the specific inhibition was found. Conclusion The results mentioned above demonstrated that cold-adapted, attenuated reassortant H3N2 subtype influenza A virus was successfully generated, which laid a good foundation for the further related research.
Rota Paul A
Full Text Available Abstract Background Live, attenuated measles virus (MeV vaccine strains were generated by adaptation to cell culture. The genetic basis for the attenuation of the vaccine strains is unknown. We previously reported that adaptation of a pathogenic, wild-type MeV to Vero cells or primary chicken embryo fibroblasts (CEFs resulted in a loss of pathogenicity in rhesus macaques. The CEF-adapted virus (D-CEF contained single amino acid changes in the C and matrix (M proteins and two substitutions in the shared amino terminal domain of the phosphoprotein (P and V protein. The Vero-adapted virus (D-VI had a mutation in the cytoplasmic tail of the hemagglutinin (H protein. Results In vitro assays were used to test the functions of the wild-type and mutant proteins. The substitution in the C protein of D-CEF decreased its ability to inhibit mini-genome replication, while the wild-type and mutant M proteins inhibited replication to the same extent. The substitution in the cytoplasmic tail of the D-VI H protein resulted in reduced fusion in a quantitative fusion assay. Co-expression of M proteins with wild-type fusion and H proteins decreased fusion activity, but the mutation in the M protein of D-CEF did not affect this function. Both mutations in the P and V proteins of D-CEF reduced the ability of these proteins to inhibit type I and II interferon signaling. Conclusion Adaptation of a wild-type MeV to cell culture selected for genetic changes that caused measurable functional differences in viral proteins.
Mauck, K E; De Moraes, C M; Mescher, M C
host and apparently maladaptive with respect to virus transmission (e.g., host plant quality for aphids was significantly improved in this instance, and aphid dispersal was reduced). Taken together, these findings provide evidence of adaption by CMV to local hosts (including reduced infectivity and replication in novel versus native hosts) and further suggest that such adaptation may extend to effects on host-plant traits mediating interactions with aphid vectors. Thus, these results are consistent with the hypothesis that virus effects on host-vector interactions can be adaptive, and they suggest that multi-host pathogens may exhibit adaptation with respect to these and other effects on host phenotypes, perhaps especially in homogeneous monocultures.
Pelto, Debra J; Sadler, Georgia Robins; Njoku, Ogo; Rodriguez, Maria Carina; Villagra, Cristina; Malcarne, Vanessa L; Riley, Natasha E; Behar, Alma I; Jandorf, Lina
The pilot study reported in this article culturally and linguistically adapted an educational intervention to promote cancer clinical trials (CCTs) participation among Latinas/os and African Americans. The single-session slide presentation with embedded videos, originally developed through a campus-community partnership in Southern California, was chosen for adaptation because it was perceived to fit the CORRECT model of innovation (credible, observable, relevant, relatively advantageous, easy to understand, compatible, and testable) and because of the potential to customize any components not identified as core, allowing them to be revised for cultural and linguistic alignment in New York City. Most of the 143 community participants (76.2%) were female; most (54.6%) were older than 59 years. More than half (78.3%) preferred to speak English or were bilingual in English and Spanish. A large proportion (41.3%) had not completed high school. Knowledge and perceived benefits and barriers regarding CCT showed small, though statistically significant, increases. There were no statistically significant group differences for changes in mean knowledge, perceived benefits, or perceived barriers when examined by ethnicity, education level, language, or other included sociodemographic variables. However, a small, but statistically significant difference in perceived barriers was observed when examined by country of origin, with the foreign born score worsening 0.08 points (SD = 0.47, p = .007) on the 5-point Likert-type scale administered posteducation compared to preeducation. Participants' open-ended comments demonstrated the acceptability of the topic and intervention. This adaptation resulted in an intervention with the potential to educate African American and Latina/o general community members in a new geographic region about the purpose, methods, and benefits of CCTs. PMID:26493870
Sastre, Patricia; Pérez, Teresa; Costa, Sofia; Yang, Xiaoping; Räber, Alex; Blome, Sandra; Goller, Katja V; Gallardo, Carmina; Tapia, Istar; García, Julia; Sanz, Antonio; Rueda, Paloma
Classical swine fever (CSF) and African swine fever (ASF) are both highly contagious diseases of domestic pigs and wild boar and are clinically indistinguishable. For both diseases, antibody detection is an integral and crucial part of prevention and control measures. The purpose of our study was to develop and initially validate a duplex pen-side test for simultaneous detection and differentiation of specific antibodies against CSF virus (CSFV) and ASF virus (ASFV). The test was based on the major capsid protein VP72 of ASFV and the structural protein E2 of CSFV, both considered the most immunogenic proteins of these viruses. The performance of the pen-side test was evaluated using a panel of porcine samples consisting of experimental, reference, and field sera, with the latter collected from European farms free of both diseases. The new lateral flow assay was able to detect specific antibodies to ASFV or CSFV, showing good levels of sensitivity and specificity. These preliminary data indicate the potential of the newly developed pen-side test for rapid differential detection of antibodies found in the 2 diseases, which is of particular importance in the field and in front-line laboratories where equipment and skilled personnel are limited and control of ASF and CSF is crucial. PMID:27400954
Full Text Available A Fluorescence resonance energy transfer (FRET real-time reverse-transcription (rRT-PCR assay was developed that distinguishes stains of South African and European highly pathogenic (HPAI from low pathogenicity (LPAI H5 avian influenza viruses in the absence of virus isolation, irrespective of the length of insertion at the hemagglutinin cleavage site (H0. The assay was used to pathotype H5-type viruses detected by rRT-PCR in ostrich tracheal swabs collected during the 2006 HPAI H5N2 outbreak in the Western Cape Province.
Kang Hae Ji
Full Text Available Abstract Background Tanganya virus (TGNV, the only shrew-associated hantavirus reported to date from sub-Saharan Africa, is harbored by the Therese's shrew (Crocidura theresae, and is phylogenetically distinct from Thottapalayam virus (TPMV in the Asian house shrew (Suncus murinus and Imjin virus (MJNV in the Ussuri white-toothed shrew (Crocidura lasiura. The existence of myriad soricid-borne hantaviruses in Eurasia and North America would predict the presence of additional hantaviruses in sub-Saharan Africa, where multiple shrew lineages have evolved and diversified. Methods Lung tissues, collected in RNAlater®, from 39 Buettikofer's shrews (Crocidura buettikoferi, 5 Jouvenet's shrews (Crocidura jouvenetae, 9 West African pygmy shrews (Crocidura obscurior and 21 African giant shrews (Crocidura olivieri captured in Côte d'Ivoire during 2009, were systematically examined for hantavirus RNA by RT-PCR. Results A genetically distinct hantavirus, designated Azagny virus (AZGV, was detected in the West African pygmy shrew. Phylogenetic analysis of the S, M and L segments, using maximum-likelihood and Bayesian methods, under the GTR+I+Γ model of evolution, showed that AZGV shared a common ancestry with TGNV and was more closely related to hantaviruses harbored by soricine shrews than to TPMV and MJNV. That is, AZGV in the West African pygmy shrew, like TGNV in the Therese's shrew, did not form a monophyletic group with TPMV and MJNV, which were deeply divergent and basal to other rodent- and soricomorph-borne hantaviruses. Ancestral distributions of each hantavirus lineage, reconstructed using Mesquite 2.74, suggested that the common ancestor of all hantaviruses was most likely of Eurasian, not African, origin. Conclusions Genome-wide analysis of many more hantaviruses from sub-Saharan Africa are required to better understand how the biogeographic origin and radiation of African shrews might have contributed to, or have resulted from, the evolution
Cassidy, Omni; Sbrocco, Tracy; Vannucci, Anna; Nelson, Beatrice; Jackson-Bowen, Darlene; Heimdal, James; Mirza, Nazrat; Wilfley, Denise E.; Osborn, Robyn; Shomaker, Lauren B.; Young, Jami F.; Waldron, Heather; Carter, Michele; Tanofsky-Kraff, Marian
Objective To obtain focus group data regarding the perspectives of rural African American (AA) girls, parents/guardians, and community leaders on obesity, loss of control (LOC) eating, relationships, and interpersonal psychotherapy for the prevention of excessive weight gain (IPT-WG). Methods 7 focus groups (N = 50 participants) were moderated and the transcripts analyzed by Westat researchers using widely accepted methods of qualitative and thematic analysis. A session was held with experts ...
B.F. Von Teichman
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.
Yannick Griep; Elfi Baillien; Wouter Vleugels; Sebastiaan Rothmann; Hans De Witte
This study investigates affective experience as a function of unemployment duration in South Africa. The study contrasts two models. The stress reaction model proposes a linear decrease of affective experience as unemployment prolongs. The adaptation model assumes a curvilinear pattern between affective experience and unemployment duration. Analysis of variance (ANOVA) with contrast revealed no differences in affective experience between short-term (N = 101), long-term (N = 152) and very long...
Kuhmann, S E; Madani, N; Diop, O M; Platt, E J; Morvan, J; Müller-Trutwin, M C; Barré-Sinoussi, F; Kabat, D
In contrast to humans, several primate species are believed to have harbored simian immunodeficiency viruses (SIVs) since ancient times. In particular, the geographically dispersed species of African green monkeys (AGMs) are all infected with highly diversified SIVagm viruses at high prevalences (greater than 50% of sexually mature individuals) without evident diseases, implying that the progenitor monkeys were infected prior to their dispersal. If this is correct, AGMs would be expected to have accumulated frequent resistance-conferring polymorphisms in host genes that are important for SIV replication. Accordingly, we analyzed the coding sequences of the CCR5 coreceptors from 26 AGMs (52 alleles) in distinct populations of the four species. These samples contained 29 nonsynonymous coding changes and only 15 synonymous nucleotide substitutions, implying intense functional selection. Moreover, 24 of the resulting amino acid substitutions were tightly clustered in the CCR5 amino terminus (D13N in the vervets and Y14N in the tantalus species) or in the first extracellular loop (Q93R and Q93K in all species). The Y14N substitution was extremely frequent in the 12 wild-born African tantalus, with 7 monkeys being homozygous for this substitution and 4 being heterozygous. Although two of these heterozygotes and the only wild-type homozygote were naturally infected with SIVagm, none of the Y14N homozygotes were naturally infected. A focal infectivity assay for SIVagm indicated that all five tested SIVagms efficiently use CCR5 as a coreceptor and that they also use CXCR6 (STRL33/Bonzo) and GPR15 (BOB) with lower efficiencies but not CXCR4. Interestingly, the D13N, Y14N, Q93R, and Q93K substitutions in AGM CCR5 all strongly inhibited infections by the SIVagm isolates in vitro. The Y14N substitution eliminates a tyrosine sulfation site that is important for infections and results in partial N-linked glycosylation (i.e., 60% efficiency) at this position. Nevertheless, the CCR
Bøtner, Anette; Kakker, Naresh K.; Barbezange, Cyril;
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......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...... from the O/UKG/34/2001 or A/Turkey 2/2006 field viruses, were constructed using the backbone from the O1K B64 cDNA, and viable viruses (O1K/O-UKG and O1K/A-Tur, respectively) were successfully rescued in each case. These viruses grew well in primary bovine thyroid cells but grew less efficiently in BHK...
Hadsbjerg, Johanne; Friis, Martin B; Fahnøe, Ulrik; Nielsen, Jens; Belsham, Graham J; Rasmussen, Thomas Bruun
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 of the subdomain IIIf of the internal ribosome entry site (IRES) that directs the initiation of protein synthesis. Rescued viruses were inoculated into pigs. The rescued vPader10 virus, without modifications in the IRES, induced clinical disease in pigs that was very similar to that observed previously with the parental field strain and transmission to in-contact pigs occurred. Two sequence reversions, in the NS2 and NS5B coding regions, became dominant within the virus populations in these infected pigs. Rescued viruses, with mutant IRES elements, did not induce disease and only very limited circulation of viral 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 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 adaptation and to identify key determinants of viral replication efficiency in cells and within host animals. PMID:27527774
Full Text Available Dendritic cells (DC are major players in both innate and adaptive immune responses against influenza virus. These immune responses, as well as the important interface between the innate and adaptive systems, are orchestrated by specialized subsets of DC, including conventional steady-state DC, migratory DC and plasmacytoid DC. The characteristics and efficacy of the responses are dependent on the relative activity of these DC subsets, rendering DC crucial for the development of both naïve and memory immune responses. However, due to their critical role, DC also contribute to the immunopathological processes observed during acute influenza, such as that caused by the pathogenic H5N1 viruses. Therein, the role of different DC subsets in the induction of interferon type I, proinflammatory cytokine and chemokine responses is important for the outcome of interaction between the virus and host immune defences. The present review will present current knowledge on this area, relating to the importance of DC activity for the induction of efficacious humoral and cell-mediated immune responses. This will include the main viral elements associated with the triggering or inhibition of DC activation. Finally, the current knowledge on understanding how differences in various vaccines influence the manner of immune defence induction will be presented.
Bouda, Zoewinde Henri-Noel
for planting based on the results can hardly be given, other than to use extreme caution if provenances from East Africa are introduced to West Africa, in the case of A. digitata. Until a better understanding of the two species morphology and physiology under drought stress has been achieved, there seems......For arid zones such as the Sahel, drought is one of the most important constraints to the survival and development of plants playing a key role in the livelihoods of human populations. The domestication of fruit trees such as Adansonia digitata and Parkia biglobosa for the Sub-Saharan region has...... 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...
Grobler, D G; Raath, J P; Braack, L E; Keet, D F; Gerdes, G H; Barnard, B J; Kriek, N P; Jardine, J; Swanepoel, R
A cluster of four deaths in late December 1993, marked the onset of an outbreak of disease of African elephants (Loxodonta africana) in the Kruger National Park (KNP) in South Africa, which has an estimated population of 7,500 elephants. Mortalities peaked in January 1994, with 32 deaths, and then declined steadily to reach pre-outbreak levels by September, but sporadic losses continued until November. During the outbreak altogether 64 elephants died, of which 53 (83%) were adult bulls. Archival records revealed that, in addition to the usual losses from known causes such as poaching and intraspecific fighting, sporadic deaths from unexplained causes had, in fact, occurred in widely scattered locations from at least 1987 onwards, and from that time until the perceived outbreak of disease there had been 48 such deaths involving 33 (69%) adult bulls. Carcases had frequently become decomposed or had been scavenged by the time they were found, but seven of eight elephants examined early in 1994 had lesions of cardiac failure suggestive of encephalomyocarditis (EMC)-virus infection, and the virus was isolated from the heart muscles of three fresh carcases. The results of tests for neutralizing antibody on 362 elephant sera collected for unrelated purposes from 1984 onwards and kept frozen, indicated that the virus had been present in the KNP since at least 1987. Antibody prevalences of 62 of 116 (53%) 18 of 139 (13%) and seven of 33 (21%) were found in elephants in three different regions of the KNP in 1993 and 1994. Studies had been conducted on myomorph rodents in the KNP for unrelated purposes since 1984, and trapping attempts were increased during the perceived outbreak of disease in elephants. There was a striking temporal correlation between the occurrence of a population explosion (as evidenced by markedly increased catch rates per trap-night) and a surge in prevalence of antibody to EM virus in rodents, and the occurrence of the outbreak of disease in elephants.
LaBeaud, A.D.; Cross, P.C.; Getz, W.M.; Glinka, A.; King, C.H.
Rift Valley fever virus (RVFV) is an emerging biodefense pathogen that poses significant threats to human and livestock health. To date, the interepidemic reservoirs of RVFV are not well defined. In a longitudinal survey of infectious diseases among African buffalo during 2000-2006, 550 buffalo were tested for antibodies against RVFV in 820 capture events in 302 georeferenced locations in Kruger National Park, South Africa. Overall, 115 buffalo (21%) were seropositive. Seroprevalence of RVFV was highest (32%) in the first study year, and decreased progressively in subsequent years, but had no detectable impact on survival. Nine (7%) of 126 resampled, initially seronegative animals seroconverted during periods outside any reported regional RVFV outbreaks. Seroconversions for RVFV were detected in significant temporal clusters during 2001-2003 and in 2004. These findings highlight the potential importance of wildlife as reservoirs for RVFV and interepidemic RVFV transmission in perpetuating regional RVFV transmission risk. Copyright ?? 2011 by The American Society of Tropical Medicine and Hygiene.
M. H. Mohammed
Full Text Available The susceptibility of the primary chick embryo chorioallontoic membrane cells to infectious bronchitis virus was evaluated after twenty consecutive passages in chick embryo chorioallontoic membrane cells. Virus replication was monitored by cytopathic observation, indirect immunoperoxidase, and reverse transcription polymerase chain reaction (RT-PCR. At 72 hours post-infection (p.i. in third passage, the cytopathic effect was characterized by rounding up of cells, monolayer detachment, intracytoplasmic brownish colouration was readily observed by immunoperoxidase from 24 hours p.i in third passage, and at all times the extracted viral RNA from IBV-infected monolayers was demonstrated by RT-PCR. Tissue culture ineffective dose50 (TCID50 was used to measure virus titration performed on primary chick embryo chorioallontoic membrane cells and the titre in twenty passage was 108.6 TCID50/ml. The results obtained in this study suggested that the primary chick embryo chorioallontoic membrane cells can be used for adaptation infectious bronchitis virus (IBV and may be considered a step forward for the use of these cells in the future for IBV vaccine production
Osonubi, O; Fasehun, F E
Stomatal conductance, transpiration and xylem pressure potential of African locust bean (Parkia biglobosa (Jacq.) Benth.) seedlings subjected from the sixth week after emergence to four weeks of continuous soil drought did not differ from those of well-watered, control plants until two-thirds of the available soil water had been used. In both well-watered and drought-treated plants, stomatal conductance was highest early in the day when vapor pressure deficits were low, but decreased sharply by midday when evaporative demand reached its highest value. There was no increase in stomatal conductance later in the day as vapor pressure deficit declined. The relationship between transpiration rate and xylem pressure potential showed non-linearity and hysteresis in both control and drought-treated plants, which seems to indicate that the plants had a substantial capacity to store water. The rate of leaf extension in African locust bean seedlings subjected to six consecutive 2-week cycles of soil drought declined relative to that of well-watered, control plants, whereas relative root extension increased. It appears that African locust bean seedlings minimized the impact of drought by: (1) restricting transpiration to the early part of the day when a high ratio of carbon gain to water loss can be achieved; (2) utilizing internally stored water during periods of rapid transpiration; (3) reducing the rate of leaf expansion and final leaf size in response to soil drought without reducing the rate of root extension, thereby reducing the ratio of transpiring leaf surface area to absorbing root surface area.
Misinzo, Gerald; Kwavi, David E; Sikombe, Christopher D; Makange, Mariam; Peter, Emma; Muhairwa, Amandus P; Madege, Michael J
African swine fever (ASF) is an acute, highly contagious and deadly viral hemorrhagic fever of domestic pigs caused by African swine fever virus (ASFV), a double-stranded DNA virus of the family Asfarviridae. In this study, molecular diagnosis and characterization of outbreak ASFV in northern Tanzania, was performed on spleen, lymph node, kidney, and heart samples collected in June and July 2013 from domestic pigs that died during a hemorrhagic disease outbreak. Confirmatory diagnosis of ASF was performed using polymerase chain reaction (PCR) by partial amplification of B646L gene of ASFV encoding the major capsid protein p72 using PPA1/PPA2 primers. PCR using PPA1/PPA2 primers produced an expected PCR product size, confirming ASF outbreak in northern Tanzania. In addition, nucleotide amplification and sequencing, and phylogenetic reconstruction of the variable 3'-end of the B646L gene and complete E183L gene encoding the inner envelope transmembrane protein p54 showed that the 2013 outbreak ASFV from northern Tanzania were 100 % identical and clustered into ASFV B646L (p72) and E183L (p54) genotype X. Furthermore, the tetrameric amino acid repeats within the central variable region (CVR) of the B602L gene coding for the J9L protein had the signature BNBA(BN)5NA with a single novel tetramer NVDI (repeat code N). The results of the present study confirm an ASF outbreak in northern Tanzania in the year 2013 and show that the present outbreak ASFV is closely related to other ASFV from ticks, warthogs, and domestic pigs previously reported from Tanzania.
P. D. Luka
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.
... HUMAN SERVICES QUARANTINE, INSPECTION, LICENSING FOREIGN QUARANTINE Importations § 71.56 African rodents... Control and Prevention (CDC) from causing an animal to be quarantined, re-exported, or destroyed under a... obtain such written permission from CDC, you must send a written request to Division of Global...
Morris Linzette D
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
Richardson Jason H
Full Text Available Abstract Background Several observations support the hypothesis that vector-driven selection plays an important role in shaping dengue virus (DENV genetic diversity. Clustering of DENV genetic diversity at a particular location may reflect underlying genetic structure of vector populations, which combined with specific vector genotype × virus genotype (G × G interactions may promote adaptation of viral lineages to local mosquito vector genotypes. Although spatial structure of vector polymorphism at neutral genetic loci is well-documented, existence of G × G interactions between mosquito and virus genotypes has not been formally demonstrated in natural populations. Here we measure G × G interactions in a system representative of a natural situation in Thailand by challenging three isofemale families from field-derived Aedes aegypti with three contemporaneous low-passage isolates of DENV-1. Results Among indices of vector competence examined, the proportion of mosquitoes with a midgut infection, viral RNA concentration in the body, and quantity of virus disseminated to the head/legs (but not the proportion of infected mosquitoes with a disseminated infection strongly depended on the specific combinations of isofemale families and viral isolates, demonstrating significant G × G interactions. Conclusion Evidence for genetic specificity of interactions in our simple experimental design indicates that vector competence of Ae. aegypti for DENV is likely governed to a large extent by G × G interactions in genetically diverse, natural populations. This result challenges the general relevance of conclusions from laboratory systems that consist of a single combination of mosquito and DENV genotypes. Combined with earlier evidence for fine-scale genetic structure of natural Ae. aegypti populations, our finding indicates that the necessary conditions for local DENV adaptation to mosquito vectors are met.
Kyla Marie Sawyer-Kurian
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.
Molly R Perkins; Briant, Judith A.; Calantone, Nina; Whitted, Sonya; Vinton, Carol L.; Klatt, Nichole R.; Ourmanov, Ilnour; Ortiz, Alexandra M.; Vanessa M Hirsch; Brenchley, Jason M.
African green monkeys (AGMs; genus Chlorocebus) are a natural host of simian immunodeficiency virus (SIVAGM). As they do not develop simian AIDS, there is great interest in understanding how this species has evolved to avoid immunodeficiency. Adult African green monkeys naturally have low numbers of CD4 T cells and a large population of major histocompatibility complex class II-restricted CD8αdim T cells that are generated through CD4 downregulation in CD4+ T cells. Mechanisms that drive this...
Nicole E Forbes
Full Text Available The role of the NS1 protein in modulating influenza A virulence and host range was assessed by adapting A/Hong Kong/1/1968 (H3N2 (HK-wt to increased virulence in the mouse. Sequencing the NS genome segment of mouse-adapted variants revealed 11 mutations in the NS1 gene and 4 in the overlapping NEP gene. Using the HK-wt virus and reverse genetics to incorporate mutant NS gene segments, we demonstrated that all NS1 mutations were adaptive and enhanced virus replication (up to 100 fold in mouse cells and/or lungs. All but one NS1 mutant was associated with increased virulence measured by survival and weight loss in the mouse. Ten of twelve NS1 mutants significantly enhanced IFN-β antagonism to reduce the level of IFN β production relative to HK-wt in infected mouse lungs at 1 day post infection, where 9 mutants induced viral yields in the lung that were equivalent to or significantly greater than HK-wt (up to 16 fold increase. Eight of 12 NS1 mutants had reduced or lost the ability to bind the 30 kDa cleavage and polyadenylation specificity factor (CPSF30 thus demonstrating a lack of correlation with reduced IFN β production. Mutant NS1 genes resulted in increased viral mRNA transcription (10 of 12 mutants, and protein production (6 of 12 mutants in mouse cells. Increased transcription activity was demonstrated in the influenza mini-genome assay for 7 of 11 NS1 mutants. Although we have shown gain-of-function properties for all mutant NS genes, the contribution of the NEP mutations to phenotypic changes remains to be assessed. This study demonstrates that NS1 is a multifunctional virulence factor subject to adaptive evolution.
Full Text Available Ecosystem services are embedded in complex adaptive systems. These systems are riddled with nonlinearities, uncertainties, and surprises, and are made increasingly complex by the many human responses to problems or changes arising within them. In this paper we attempt to determine whether there are certain factors that characterize effective responses in complex systems. We construct a framework for response evaluation with three interconnected scopes or spatial and temporal domains: the scope of an impact, the scope of the awareness of the impact, and the scope of the power or influence to respond. Drawing from the experience of the Southern African Millennium Ecosystem Assessment (SAfMA, we explore the applicability of this framework to the example of water management in southern Africa, where an ongoing paradigm shift in some areas has enabled a transition from supply-side to demand-side responses and the creation of new institutions to manage water across scales. We suggest that the most effective responses exhibit congruence between the impact, awareness, and power scopes; distribute impacts across space and time; expand response options; enhance social memory; and depend on power-distributing mechanisms. We conclude by stressing the need for sufficient flexibility to adapt responses to the specific, ever-evolving contexts in which they are implemented. Although our discussion focuses on water in southern Africa, we believe that the framework has broad applicability to a range of complex systems and places.
Capucine de Fouchier
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.
Khan, Akhtar J; Akhtar, Sohail; Al-Matrushi, Abdulrahman M; Fauquet, Claude M; Briddon, Rob W
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. PMID:23085885
Full Text Available BACKGROUND: African horse sickness virus (AHSV causes a non-contagious, infectious disease in equids, with mortality rates that can exceed 90% in susceptible horse populations. AHSV vaccines play a crucial role in the control of the disease; however, there are concerns over the use of polyvalent live attenuated vaccines particularly in areas where AHSV is not endemic. Therefore, it is important to consider alternative approaches for AHSV vaccine development. We have carried out a pilot study to investigate the ability of recombinant modified vaccinia Ankara (MVA vaccines expressing VP2, VP7 or NS3 genes of AHSV to stimulate immune responses against AHSV antigens in the horse. METHODOLOGY/PRINCIPAL FINDINGS: VP2, VP7 and NS3 genes from AHSV-4/Madrid87 were cloned into the vaccinia transfer vector pSC11 and recombinant MVA viruses generated. Antigen expression or transcription of the AHSV genes from cells infected with the recombinant viruses was confirmed. Pairs of ponies were vaccinated with MVAVP2, MVAVP7 or MVANS3 and both MVA vector and AHSV antigen-specific antibody responses were analysed. Vaccination with MVAVP2 induced a strong AHSV neutralising antibody response (VN titre up to a value of 2. MVAVP7 also induced AHSV antigen-specific responses, detected by western blotting. NS3 specific antibody responses were not detected. CONCLUSIONS: This pilot study demonstrates the immunogenicity of recombinant MVA vectored AHSV vaccines, in particular MVAVP2, and indicates that further work to investigate whether these vaccines would confer protection from lethal AHSV challenge in the horse is justifiable.
Martinez-Torrecuadrada, J.L.; Langeveld, J.P.M.; Venteo, A.;
function of VP5, the other component of the capsid, is unknown. In this report, AHSV VP5, expressed in insect cells alone or together with VP2, was able to induce AHSV-specific neutralizing antibodies. Moreover, two VP5-specific monoclonal antibodies (MAbs) that were able to neutralize the virus in a....... 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...
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
Rippke, Ulrike; Ramirez-Villegas, Julian; Jarvis, Andy; Vermeulen, Sonja J.; Parker, Louis; Mer, Flora; Diekkrüger, Bernd; Challinor, Andrew J.; Howden, Mark
Climate change is projected to constitute a significant threat to food security if no adaptation actions are taken. Transformation of agricultural systems, for example switching crop types or moving out of agriculture, is projected to be necessary in some cases. However, little attention has been paid to the timing of these transformations. Here, we develop a temporal uncertainty framework using the CMIP5 ensemble to assess when and where cultivation of key crops in sub-Saharan Africa becomes unviable. We report potential transformational changes for all major crops during the twenty-first century, as climates shift and areas become unsuitable. For most crops, however, transformation is limited to small pockets (banana is transformation more widespread (~30% area for maize and banana, 60% for beans). We envisage three overlapping adaptation phases to enable projected transformational changes: an incremental adaptation phase focused on improvements to crops and management, a preparatory phase that establishes appropriate policies and enabling environments, and a transformational adaptation phase in which farmers substitute crops, explore alternative livelihoods strategies, or relocate. To best align policies with production triggers for no-regret actions, monitoring capacities to track farming systems as well as climate are needed.
Sullivan, Patrick S; Stephenson, Rob; Grazter, Beau; Wingood, Gina; Diclemente, Ralph; Allen, Susan; Hoff, Colleen; Salazar, Laura; Scales, Lamont; Montgomery, Jeanne; Schwartz, Ann; Barnes, Jasper; Grabbe, Kristina
To respond to the need for new HIV prevention services for men who have sex with men (MSM) in the United States, and to respond to new data on the key role of main partnerships in US MSM epidemics, we sought to develop a new service for joint HIV testing of male couples. We used the ADAPT-ITT framework to guide our work. From May 2009 to July 2013, a multiphase process was undertaken to identify an appropriate service as the basis for adaptation, collect data to inform the adaptation, adapt the testing service, develop training materials, test the adapted service, and scale up and evaluate the initial version of the service. We chose to base our adaptation on an African couples HIV testing service that was developed in the 1980s and has been widely disseminated in low- and middle-income countries. Our adaptation was informed by qualitative data collections from MSM and HIV counselors, multiple online surveys of MSM, information gathering from key stakeholders, and theater testing of the adapted service with MSM and HIV counselors. Results of initial testing indicate that the adapted service is highly acceptable to MSM and to HIV counselors, that there are no evident harms (e.g., intimate partner violence, relationship dissolution) associated with the service, and that the service identifies a substantial number of HIV serodiscordant male couples. The story of the development and scale-up of the adapted service illustrates how multiple public and foundation funding sources can collaborate to bring a prevention adaptation from concept to public health application, touching on research, program evaluation, implementation science, and public health program delivery. The result of this process is an adapted couples HIV testing approach, with training materials and handoff from academic partners to public health for assessment of effectiveness and consideration of the potential benefits of implementation; further work is needed to optimally adapt the African couples
Safronetz, David; Prescott, Joseph; Haddock, Elaine; Scott, Dana P.; Feldmann, Heinz; Ebihara, Hideki
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...
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.
Russell, Rodney S; Meunier, Jean-Christophe; Takikawa, Shingo;
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......, and NS2 all increased virus production. A single-cycle replication assay in CD81-deficient cells was developed to study more precisely the effect of the adaptive mutations. The E2 mutation had minimal effect on the amount of infectious virus released but probably enhanced entry into cells. In contrast...
Chua, Chong-Long; Sam, I-Ching; Merits, Andres; Chan, Yoke-Fun
Background Chikungunya virus (CHIKV) is a re-emerging mosquito-borne virus which causes epidemics of fever, severe joint pain and rash. Between 2005 and 2010, the East/Central/South African (ECSA) genotype was responsible for global explosive outbreaks across India, the Indian Ocean and Southeast Asia. From late 2013, Asian genotype CHIKV has caused outbreaks in the Americas. The characteristics of cross-antibody efficacy and epitopes are poorly understood. Methodology/Principal Findings We characterized human immune sera collected during two independent outbreaks in Malaysia of the Asian genotype in 2006 and the ECSA genotype in 2008–2010. Neutralizing capacity was analyzed against representative clinical isolates as well as viruses rescued from infectious clones of ECSA and Asian CHIKV. Using whole virus antigen and recombinant E1 and E2 envelope glycoproteins, we further investigated antibody binding sites, epitopes, and antibody titers. Both ECSA and Asian sera demonstrated stronger neutralizing capacity against the ECSA genotype, which corresponded to strong epitope-antibody interaction. ECSA serum targeted conformational epitope sites in the E1-E2 glycoprotein, and E1-E211K, E2-I2T, E2-H5N, E2-G118S and E2-S194G are key amino acids that enhance cross-neutralizing efficacy. As for Asian serum, the antibodies targeting E2 glycoprotein correlated with neutralizing efficacy, and I2T, H5N, G118S and S194G altered and improved the neutralization profile. Rabbit polyclonal antibody against the N-terminal linear neutralizing epitope from the ECSA sequence has reduced binding capacity and neutralization efficacy against Asian CHIKV. These findings imply that the choice of vaccine strain may impact cross-protection against different genotypes. Conclusion/Significance Immune serum from humans infected with CHIKV of either ECSA or Asian genotypes showed differences in binding and neutralization characteristics. These findings have implications for the continued
Trevor G Bell
Full Text Available Hepatitis B virus (HBV and human immunodeficiency virus (HIV share transmission routes and are endemic in sub-Saharan Africa. The objective of the present study was to use the Taormina definition of occult HBV infection, together with stringent amplification conditions, to determine the prevalence and characteristics of HBV infection in antiretroviral treatment (ART-naïve HIV(+ve adults in a rural cohort in South Africa. The presence of HBV serological markers was determined by enzyme linked immunoassay (ELISA tests. HBV DNA-positivity was determined by polymerase chain reaction (PCR of at least two of three different regions of the HBV genome. HBV viral loads were determined by real-time PCR. Liver fibrosis was determined using the aspartate aminotransferase-to-platelet ratio index. Of the 298 participants, 231 (77.5% showed at least one HBV marker, with 53.7% HBV DNA(-ve (resolved and 23.8% HBV DNA(+ve (current [8.7% HBsAg(+ve: 15.1% HBsAg(-ve]. Only the total number of sexual partners distinguished HBV DNA(+ve and HBV DNA(-ve participants, implicating sexual transmission of HBV and/or HIV. It is plausible that sexual transmission of HBV and/or HIV may result in a new HBV infection, superinfection and re-activation as a consequence of immunesuppression. Three HBsAg(-ve HBV DNA(+ve participants had HBV viral loads <200 IU/ml and were therefore true occult HBV infections. The majority of HBsAg(-ve HBV DNA(+ve participants did not differ from HBsAg(+ve HBV DNA(+ve (overt participants in terms of HBV viral loads, ALT levels or frequency of liver fibrosis. Close to a quarter of HIV(+ve participants were HBV DNA(+ve, of which the majority were HBsAg(-ve and were only detected using nucleic acid testing. Detection of HBsAg(-ve HBV DNA(+ve subjects is advisable considering they were clinically indistinguishable from HBsAg(+ve HBV DNA(+ve individuals and should not be overlooked, especially if lamivudine is included in the ART.
Omilabu, S A; Salu, O B; Oke, B O; James, A B
The first epidemic of Ebola haemorrhagic disease in West Africa is the largest and longest Ebola epidemic till date, where the outbreak notably involved three countries with distant spread to other countries. It has caused significant mortality, with reported case fatality rates of up to 70%. Data and relevant information were extracted from the review of majorly relevant publications/papers about the Ebola epidemic in West Africa and other previous outbreaks of Ebola virus (EBOV). As of 2016, with the epidemic under control, the World Health Organization has warned that flare-ups of the disease are likely to continue for some time as recently occurred in Sierra Leone and the on-going in Guinea. As this may not be the last outbreak of Ebola virus disease (EVD) in West Africa, there is a need to focus on diagnostic and research capacity required to curtail EVD with adequate measures for emergency preparedness and policies for innovative treatment strategies. PMID:27424613
Guinat, Claire; Reis, Ana Luisa; Netherton, Christopher L; Goatley, Lynnette; Pfeiffer, Dirk U; Dixon, Linda
African swine fever virus (ASFV) is a highly virulent swine pathogen that has spread across Eastern Europe since 2007 and for which there is no effective vaccine or treatment available. The dynamics of shedding and excretion is not well known for this currently circulating ASFV strain. Therefore, susceptible pigs were exposed to pigs intramuscularly infected with the Georgia 2007/1 ASFV strain to measure those dynamics through within- and between-pen transmission scenarios. Blood, oral, nasal and rectal fluid samples were tested for the presence of ASFV by virus titration (VT) and quantitative real-time polymerase chain reaction (qPCR). Serum was tested for the presence of ASFV-specific antibodies. Both intramuscular inoculation and contact transmission resulted in development of acute disease in all pigs although the experiments indicated that the pathogenesis of the disease might be different, depending on the route of infection. Infectious ASFV was first isolated in blood among the inoculated pigs by day 3, and then chronologically among the direct and indirect contact pigs, by day 10 and 13, respectively. Close to the onset of clinical signs, higher ASFV titres were found in blood compared with nasal and rectal fluid samples among all pigs. No infectious ASFV was isolated in oral fluid samples although ASFV genome copies were detected. Only one animal developed antibodies starting after 12 days post-inoculation. The results provide quantitative data on shedding and excretion of the Georgia 2007/1 ASFV strain among domestic pigs and suggest a limited potential of this isolate to cause persistent infection.
Li, Ming; Wang, Rui; Zhao, Dahe; Xiang, Hua
The clustered regularly interspaced short palindromic repeat (CRISPR)-Cas system mediates adaptive immunity against foreign nucleic acids in prokaryotes. However, efficient adaptation of a native CRISPR to purified viruses has only been observed for the type II-A system from a Streptococcus thermophilus industry strain, and rarely reported for laboratory strains. Here, we provide a second native system showing efficient adaptation. Infected by a newly isolated virus HHPV-2, Haloarcula hispanica type I-B CRISPR system acquired spacers discriminatively from viral sequences. Unexpectedly, in addition to Cas1, Cas2 and Cas4, this process also requires Cas3 and at least partial Cascade proteins, which are involved in interference and/or CRISPR RNA maturation. Intriguingly, a preexisting spacer partially matching a viral sequence is also required, and spacer acquisition from upstream and downstream sequences of its target sequence (i.e. priming protospacer) shows different strand bias. These evidences strongly indicate that adaptation in this system strictly requires a priming process. This requirement, if validated also true for other CRISPR systems as implied by our bioinformatic analysis, may help to explain failures to observe efficient adaptation to purified viruses in many laboratory strains, and the discrimination mechanism at the adaptation level that has confused scientists for years.
W. James Cooper; Kevin Parsons; Alyssa McIntyre; Brittany Kern; Alana McGee-Moore; R. Craig Albertson
Background How particular changes in functional morphology can repeatedly promote ecological diversification is an active area of evolutionary investigation. The African rift-lake cichlids offer a calibrated time series of the most dramatic adaptive radiations of vertebrate trophic morphology yet described, and the replicate nature of these events provides a unique opportunity to test whether common changes in functional morphology have repeatedly facilitated their ecological success. ...
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.
Pride, David T; Salzman, Julia; Relman, David A
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.
Zakaryan, Hovakim; Revilla, Yolanda
African swine fever (ASF) is among the most significant of swine diseases for which no effective vaccines and antivirals are available. The disease, which is endemic in Africa, was introduced to Trans-Caucasian countries and the Russian Federation in 2007, where it remains prevalent today among domestic pigs and wild boars. Although some measures were implemented, ASF continues to pose a global risk for all countries, and thereby highlighting the importance of vaccine and antiviral research. In this review, an overview of research efforts toward the development of effective vaccines during the past decades is presented. As an alternative to vaccine development, the current state in antiviral research against ASFV is also presented. Finally, future perspectives in vaccine and antiviral research giving emphasis on some strategies that may allow researchers to develop effective countermeasures against ASF are discussed.
Falge, Eva; Brümmer, Christian; Schmullius, Christiane; Hüttich, Christian; Scholes, Robert John; Midgley, Guy; Hickler, Thomas; Scheiter, Simon; Twine, Wayne; Bradshaw, Karen; Lück, Wolfgang; Thiel-Clemen, Thomas; Lenfers, Ulfia; Mukelabai, Mukufute; Kutsch, Werner
Nowadays, many semi-arid ecosystems are affected by at least two different kinds of disturbances: land use (change) and climate change. Based on this, it can be hypothesized that even very resilient ecosystems may not return to their initial state after disturbance, but will rather adapt to a new steady-state. We name this phenomenon "Adaptive Resilience of Ecosystems" and use it as base for the research concept of ARS AfricaE. This project wants to go beyond older approaches that only describe structural changes in savannas and their drivers. It employs functional aspects, such as the investigation of biogeochemical cycles, but also targets a deeper understanding of the functional consequences of ecosystem changes caused by multiple disturbances, and defines "degradation" as a sustained loss in the broad set of ecosystem services, i.e. a decrease in natural capital. To achieve this goal, the project will • create a network of research clusters (with natural and altered vegetation) along an aridity gradient in the Greater Karoo, Kruger National Park in South Africa, and Kataba Forest Reserve in Zambia • link biogeochemical functions with ecosystem structure, diversity of species and eco-physiological properties • describe ecosystem disturbance (and recovery) in terms of ecosystem function such as carbon balance components and water use efficiency • build an individual-based model to predict ecosystem dynamics under (post) disturbance managements • combine this model with long-term landscape dynamic information derived from remote sensing and aerial photography • develop sustainable management strategies for disturbed ecosystems and land use change
Full Text Available Recent discoveries of direct acting antivirals against Hepatitis C virus (HCV have raised hopes of effective treatment via combination therapies. Yet rapid evolution and high diversity of HCV populations, combined with the reality of suboptimal treatment adherence, make drug resistance a clinical and public health concern. We develop a general model incorporating viral dynamics and pharmacokinetics/ pharmacodynamics to assess how suboptimal adherence affects resistance development and clinical outcomes. We derive design principles and adaptive treatment strategies, identifying a high-risk period when missing doses is particularly risky for de novo resistance, and quantifying the number of additional doses needed to compensate when doses are missed. Using data from large-scale resistance assays, we demonstrate that the risk of resistance can be reduced substantially by applying these principles to a combination therapy of daclatasvir and asunaprevir. By providing a mechanistic framework to link patient characteristics to the risk of resistance, these findings show the potential of rational treatment design.
Ke, Ruian; Loverdo, Claude; Qi, Hangfei; Sun, Ren; Lloyd-Smith, James O.
Recent discoveries of direct acting antivirals against Hepatitis C virus (HCV) have raised hopes of effective treatment via combination therapies. Yet rapid evolution and high diversity of HCV populations, combined with the reality of suboptimal treatment adherence, make drug resistance a clinical and public health concern. We develop a general model incorporating viral dynamics and pharmacokinetics/ pharmacodynamics to assess how suboptimal adherence affects resistance development and clinical outcomes. We derive design principles and adaptive treatment strategies, identifying a high-risk period when missing doses is particularly risky for de novo resistance, and quantifying the number of additional doses needed to compensate when doses are missed. Using data from large-scale resistance assays, we demonstrate that the risk of resistance can be reduced substantially by applying these principles to a combination therapy of daclatasvir and asunaprevir. By providing a mechanistic framework to link patient characteristics to the risk of resistance, these findings show the potential of rational treatment design. PMID:26125950
Souto, R; Mutowembwa, P; van Heerden, J; Fosgate, G T; Heath, L; Vosloo, W
African swine fever (ASF) is a mostly fatal viral infection of domestic pigs for which there is no vaccine available. The disease is endemic to most of sub-Saharan Africa, causes severe losses and threatens food security in large parts of the continent. Naturally occurring attenuated ASF viruses have been tested as vaccine candidates, but protection was variable depending on the challenge virus. In this study, the virulence of two African isolates, one from a tick vector and the other from an indigenous pig, was determined in domestic pigs to identify a potential vaccine strain for southern Africa. Neither isolate was suitable as the tick isolate was moderately virulent and the indigenous pig virus was highly virulent. The latter was subsequently used as heterologous challenge in pigs first vaccinated with a naturally attenuated isolate previously isolated in Portugal. Although a statistically significant reduction in death rate and virus load was observed compared with unvaccinated pigs post-challenge, all pigs succumbed to infection and died.
Zhang, Ruijun; Martinez, David R; Nguyen, Quang N; Pollara, Justin; Arifin, Trina; Stolarchuk, Christina; Foulger, Andrew; Amos, Josh D; Parks, Robert; Himes, Jonathon E; Wang, Minyue; Edwards, Regina W; Trama, Ashley M; Vandergrift, Nathan; Colvin, Lisa; Dewar, Ken; Juretic, Nikoleta; Wasserscheid, Jessica; Ferrari, Guido; Liao, Hua-Xin; Permar, Sallie R
African green monkeys (AGMs) are natural primate hosts of simian immunodeficiency virus (SIV). Interestingly, features of the envelope-specific antibody responses in SIV-infected AGMs are distinct from that of HIV-infected humans and SIV-infected rhesus monkeys, including gp120-focused responses and rapid development of autologous neutralization. Yet, the lack of genetic tools to evaluate B-cell lineages hinders potential use of this unique non-human primate model for HIV vaccine development. Here we define features of the AGM Ig loci and compare the proportion of Env-specific memory B-cell populations to that of HIV-infected humans and SIV-infected rhesus monkeys. AGMs appear to have a higher proportion of Env-specific memory B cells that are mainly gp120 directed. Furthermore, AGM gp120-specific monoclonal antibodies display robust antibody-dependent cellular cytotoxicity and CD4-dependent virion capture activity. Our results support the use of AGMs to model induction of functional gp120-specific antibodies by HIV vaccine strategies. PMID:27381634
Christina L Hutson
Full Text Available Although monkeypox virus (MPXV studies in wild rodents and non-human primates have generated important knowledge regarding MPXV pathogenesis and inferences about disease transmission, it might be easier to dissect the importance of virulence factors and correlates of protection to MPXV in an inbred mouse model. Herein, we compared the two clades of MPXV via two routes of infection in the BALB/c and C57BL/6 inbred mice strains. Our studies show that similar to previous animal studies, the Congo Basin strain of MPXV was more virulent than West African MPXV in both mouse strains as evidenced by clinical signs. Although animals did not develop lesions as seen in human MPX infections, localized signs were apparent with the foot pad route of inoculation, primarily in the form of edema at the site of inoculation; while the Congo Basin intranasal route of infection led to generalized symptoms, primarily weight loss. We have determined that future studies with MPXV and laboratory mice would be very beneficial in understanding the pathogenesis of MPXV, in particular if used in in vivo imaging studies. Although this mouse model may not suffice as a model of human MPX disease, with an appropriate inbred mouse model, we can unravel many unknown aspects of MPX pathogenesis, including virulence factors, disease progression in rodent hosts, and viral shedding from infected animals. In addition, such a model can be utilized to test antivirals and the next generation of orthopoxvirus vaccines for their ability to alter the course of disease.
Njouom, Richard; Frost, Eric; Deslandes, Sylvie; Mamadou-Yaya, Fleurie; Labbé, Annie-Claude; Pouillot, Régis; Mbélesso, Pascal; Mbadingai, Sylvestre; Rousset, Dominique; Pépin, Jacques
The molecular epidemiology of hepatitis C virus (HCV) in the Central African Republic (CAR) is poorly documented. Thus, we conducted phylogenetic analyses of NS5B gene sequences from 58 HCV-infected inhabitants of a remote area of south-west CAR, which indicated that 48 (82.8%) were infected with genotype 4 (HCV-4), five (8.6%) with genotype 2 and five (8.6%) with genotype 1. HCV-4 strains were highly heterogeneous, containing previously described subtypes 4k (48%), 4c (27%), 4r (4%), 4f (4%) and unclassified subtypes (17%). To estimate the epidemic history of these HCV-4 strains, an evolutionary analysis using the coalescent approach was used. The estimated date of the most recent common ancestor of the CAR HCV-4 strains was 1539 (95% confidence intervals, 1317-1697). They exhibited a rapid, exponential spread from 1935 to 1965, simultaneously with what was recently reported in neighbouring Cameroon and Gabon. The hypothesis of a massive iatrogenic transmission during interventions for the control of endemic tropical diseases is discussed.
Full Text Available In 1999, two independent groups identified plasmacytoid dendritic cells (PDC as major type I interferon- (IFN- producing cells in the blood. Since then, evidence is accumulating that PDC are a multifunctional cell population effectively coordinating innate and adaptive immune responses. This paper focuses on the role of different immune cells and their interactions in the surveillance of alpha herpes virus infections, summarizes current knowledge on PDC surface receptors and their role in direct cell-cell contacts, and develops a risk factor model for the clinical implications of herpes simplex and varicella zoster virus reactivation. Data from studies involving knockout mice and cell-depletion experiments as well as human studies converge into a “spider web”, in which the direct and indirect crosstalk between many cell populations tightly controls acute, latent, and recurrent alpha herpes virus infections. Notably, cells involved in innate immune regulations appear to shape adaptive immune responses more extensively than previously thought.
Full Text Available Vaccinia virus (VACV is the prototypic orthopoxvirus and the vaccine used to eradicate smallpox. Here we show that VACV strain Western Reserve protein 169 is a cytoplasmic polypeptide expressed early during infection that is excluded from virus factories and inhibits the initiation of cap-dependent and cap-independent translation. Ectopic expression of protein 169 causes the accumulation of 80S ribosomes, a reduction of polysomes, and inhibition of protein expression deriving from activation of multiple innate immune signaling pathways. A virus lacking 169 (vΔ169 replicates and spreads normally in cell culture but is more virulent than parental and revertant control viruses in intranasal and intradermal murine models of infection. Intranasal infection by vΔ169 caused increased pro-inflammatory cytokines and chemokines, infiltration of pulmonary leukocytes, and lung weight. These alterations in innate immunity resulted in a stronger CD8+ T-cell memory response and better protection against virus challenge. This work illustrates how inhibition of host protein synthesis can be a strategy for virus suppression of innate and adaptive immunity.
Dalin, Carole; Conway, Declan
The connections between climate and the water-food nexus are strong and economically significant in southern Africa, yet the role of observed climate variability as a driver of production fluctuations is poorly understood. In addition, as regional collaboration strengthens through the SADC (Southern Africa Development Community) and trade with other regions increases, it is important to understand both how climate variability affects productivity and how intra- and extra-regional trade can contribute to the region's capacity to deal with climate-related productivity shocks. We use international food trade data (FAOSTAT) and a global hydrological model (H08) to quantify the water resources embedded in international food trade across southern Africa and with the rest of the world, from 1986-2011. We analyze the impacts of socio-economic, political and climatic changes on agricultural trade and embedded water resources during that period. In particular, the effects of climate variability on trade flows and crop yields are estimated, to provide insights on the potential of trade as a collaborative adaptation mechanism.
Norris, Stephen P.; Macnab, John S.; Wonham, Marjorie; de Vries, Gerda
This paper promotes the use of adapted primary literature as a curriculum and instruction innovation for use in high school. Adapted primary literature is useful for promoting an understanding of scientific and mathematical reasoning and argument and for introducing modern science into the schools. We describe a prototype adapted from a published article on a mathematical model of the spread of the West Nile virus in North America. The prototype is available as a web-based resource that includes supplemental pedagogical units. Preliminary feedback from use of the prototype in two classrooms is described and a sketch of an ongoing formal evaluation is provided.
Maredza, A T; Allie, F; Plata, G; Rey, M E C
Cassava is an important food security crop in Sub-Saharan Africa. Two episomal begomovirus-associated sequences, named Sequences Enhancing Geminivirus Symptoms (SEGS1 and SEGS2), were identified in field cassava affected by the devastating cassava mosaic disease (CMD). The sequences reportedly exacerbated CMD symptoms in the tolerant cassava landrace TME3, and the model plants Arabidopsis thaliana and Nicotiana benthamiana, when biolistically co-inoculated with African cassava mosaic virus-Cameroon (ACMV-CM) or East African cassava mosaic virus-UG2 (EACMV-UG2). Following the identification of small SEGS fragments in the cassava EST database, the intention of this study was to confirm their presence in the genome, and investigate a possible role for these sequences in CMD. We report that multiple copies of varying lengths of both SEGS1 and SEGS2 are widely distributed in the sequenced cassava genome and are present in several other cassava accessions screened by PCR. The endogenous SEGS1 and SEGS2 are in close proximity or overlapping with cassava genes, suggesting a possible role in regulation of specific biological processes. We confirm the expression of SEGS in planta using EST data and RT-PCR. The sequence features of endogenous SEGS (iSEGS) are unique but resemble non-autonomous transposable elements (TEs) such as MITEs and helitrons. Furthermore, many SEGS-associated genes, some involved in virus-host interactions, are differentially expressed in susceptible (T200) and tolerant TME3) cassava landraces infected by South African cassava mosaic virus (SACMV) of susceptible (T200) and tolerant (TME3) cassava landraces. Abundant SEGS-derived small RNAs were also present in mock-inoculated and SACMV-infected T200 and TME3 leaves. Given the known role of TEs and associated genes in gene regulation and plant immune responses, our observations are consistent with a role of these DNA elements in the host's regulatory response to geminiviruses.
Maredza, A T; Allie, F; Plata, G; Rey, M E C
Cassava is an important food security crop in Sub-Saharan Africa. Two episomal begomovirus-associated sequences, named Sequences Enhancing Geminivirus Symptoms (SEGS1 and SEGS2), were identified in field cassava affected by the devastating cassava mosaic disease (CMD). The sequences reportedly exacerbated CMD symptoms in the tolerant cassava landrace TME3, and the model plants Arabidopsis thaliana and Nicotiana benthamiana, when biolistically co-inoculated with African cassava mosaic virus-Cameroon (ACMV-CM) or East African cassava mosaic virus-UG2 (EACMV-UG2). Following the identification of small SEGS fragments in the cassava EST database, the intention of this study was to confirm their presence in the genome, and investigate a possible role for these sequences in CMD. We report that multiple copies of varying lengths of both SEGS1 and SEGS2 are widely distributed in the sequenced cassava genome and are present in several other cassava accessions screened by PCR. The endogenous SEGS1 and SEGS2 are in close proximity or overlapping with cassava genes, suggesting a possible role in regulation of specific biological processes. We confirm the expression of SEGS in planta using EST data and RT-PCR. The sequence features of endogenous SEGS (iSEGS) are unique but resemble non-autonomous transposable elements (TEs) such as MITEs and helitrons. Furthermore, many SEGS-associated genes, some involved in virus-host interactions, are differentially expressed in susceptible (T200) and tolerant TME3) cassava landraces infected by South African cassava mosaic virus (SACMV) of susceptible (T200) and tolerant (TME3) cassava landraces. Abundant SEGS-derived small RNAs were also present in mock-inoculated and SACMV-infected T200 and TME3 leaves. Given the known role of TEs and associated genes in gene regulation and plant immune responses, our observations are consistent with a role of these DNA elements in the host's regulatory response to geminiviruses. PMID:25920485
We normally think of evolution occurring in a population of organisms, in response to their external environment. Rapid evolution of cellular populations also occurs within our bodies, as the adaptive immune system works to eliminate infection. Some pathogens, such as HIV, are able to persist in a host for extended periods of time, during which they also evolve to evade the immune response. In this talk I will introduce an analytical framework for the rapid co-evolution of B-cell and viral populations, based on the molecular interactions between them. Since the co-evolution of antibodies and viruses is perpetually out of equilibrium, I will show how to quantify the amount of adaptation in each of the two populations by analysis of their co-evolutionary history. I will discuss the consequences of competition between lineages of antibodies, and characterize the fate of a given lineage dependent on the state of the antibody and viral populations. In particular, I will discuss the conditions for emergence of highly potent broadly neutralizing antibodies, which are now recognized as critical for designing an effective vaccine against HIV.
Full Text Available BACKGROUND: Proteolytic processing of the Lassa virus envelope glycoprotein precursor GP-C by the host proprotein convertase site 1 protease (S1P is a prerequisite for the incorporation of the subunits GP-1 and GP-2 into viral particles and, hence, essential for infectivity and virus spread. Therefore, we tested in this study the concept of using S1P as a target to block efficient virus replication. METHODOLOGY/PRINCIPAL FINDING: We demonstrate that stable cell lines inducibly expressing S1P-adapted alpha(1-antitrypsin variants inhibit the proteolytic maturation of GP-C. Introduction of the S1P recognition motifs RRIL and RRLL into the reactive center loop of alpha(1-antitrypsin resulted in abrogation of GP-C processing by endogenous S1P to a similar level observed in S1P-deficient cells. Moreover, S1P-specific alpha(1-antitrypsins significantly inhibited replication and spread of a replication-competent recombinant vesicular stomatitis virus expressing the Lassa virus glycoprotein GP as well as authentic Lassa virus. Inhibition of viral replication correlated with the ability of the different alpha(1-antitrypsin variants to inhibit the processing of the Lassa virus glycoprotein precursor. CONCLUSIONS/SIGNIFICANCE: Our data suggest that glycoprotein cleavage by S1P is a promising target for the development of novel anti-arenaviral strategies.
Phan, Tung G; Vo, Nguyen P; Bonkoungou, Isidore J O; Kapoor, Amit; Barro, Nicolas; O'Ryan, Miguel; Kapusinszky, Beatrix; Wang, Chunling; Delwart, Eric
Parvoviruses cause a variety of mild to severe symptoms or asymptomatic infections in humans and animals. During a viral metagenomic analysis of feces from children with acute diarrhea in Burkina Faso, we identified in decreasing prevalence nucleic acids from anelloviruses, dependoviruses, sapoviruses, enteroviruses, bocaviruses, noroviruses, adenoviruses, parechoviruses, rotaviruses, cosavirus, astroviruses, and hepatitis B virus. Sequences from a highly divergent parvovirus, provisionally called bufavirus, were also detected whose NS1 and VP1 proteins showed parvoviruses. Four percent of the fecal samples were PCR positive for this new parvovirus, including a related bufavirus species showing only 72% identity in VP1. The high degree of genetic divergence of these related genomes from those of other parvoviruses indicates the presence of a proposed new Parvoviridae genus containing at least two species. Studies of the tropism and pathogenicity of these novel parvoviruses will be facilitated by the availability of their genome sequences.
Liu, Jiao; Yang, Jun; Bi, Huiping; Zhang, Peng
Cassava mosaic disease, caused by cassava begomoviruses, is the most serious disease for cassava in Africa. However, the pathogenesis of this disease is poorly understood. We employed high throughput digital gene expression profiling based on the Illumina Solexa sequencing technology to investigate the global transcriptional response of cassava to African cassava mosaic virus infection. We found that 3,210 genes were differentially expressed in virus-infected cassava leaves. Gene ontology term and Kyoto Encyclopedia of Genes and Genomes pathway analysis indicated that genes implicated in photosynthesis were most affected, consistent with the chlorotic symptoms observed in infected leaves. The upregulation of chlorophyll degradation genes, including the genes encoding chlorophyllase, pheophytinase, and pheophorbide a oxygenase, and downregulation of genes encoding the major apoproteins in light-harvesting complex II were confirmed by qRT-PCR. These findings, together with the reduction of chlorophyll b content and fewer grana stacks in the infected leaf cells, reveal that the degradation of chlorophyll plays an important role in African cassava mosaic virus symptom development. This study will provide a road map for future investigations into viral pathogenesis.
Full Text Available The Mkuze Game Reserve (MGR, in north-eastern KwaZulu-Natal Province, South Africa is an African swine fever virus (ASF controlled area. In a survey conducted in 1978, ASF prevalence in warthogs and Ornithodoros ticks in MGR was determined to be 2 % and 0.06 %, respectively. These values, acknowledged as being unusually low compared to other East and southern African ASF-positive sylvatic-cycle host populations, have not been assessed since. The availability of a sensitive PCR-based virus detection method, developed specifically for the sylvatic tampan host, prompted a re-evaluation of ASF virus (ASFV prevalence in MGR ticks. Of the 98 warthog burrows inspected for Ornithodoros presence, 59 (60.2 % were found to contain tampans and tick sampling was significantly male-biased. Whilst gender sampling-bias is not unusual, the 27 % increase in infestation rate of warthog burrows since the 1978 survey is noteworthy as it anticipates a concomitant increase in ASFV prevalence, particularly in light of the high proportion (75 % of adult ticks sampled. However, despite DNA integrity being confirmed by internal control amplification of the host 16S gene, PCR screening failed to detect ASFV. These results suggest that ASFV has either disappeared from MGR or if present, is localized, occurring at exceptionally low levels. Further extensive surveys are required to establish the ASFV status of sylvatic hosts in this controlled area.
Full Text Available Adaptive evolution is characterized by positive and parallel, or repeated selection of mutations. Mouse adaptation of influenza A virus (IAV produces virulent mutants that demonstrate positive and parallel evolution of mutations in the hemagglutinin (HA receptor and non-structural protein 1 (NS1 interferon antagonist genes. We now present a genomic analysis of all 11 genes of 39 mouse adapted IAV variants from 10 replicate adaptation experiments. Mutations were mapped on the primary and structural maps of each protein and specific mutations were validated with respect to virulence, replication, and RNA polymerase activity. Mouse adapted (MA variants obtained after 12 or 20-21 serial infections acquired on average 5.8 and 7.9 nonsynonymous mutations per genome of 11 genes, respectively. Among a total of 115 nonsynonymous mutations, 51 demonstrated properties of natural selection including 27 parallel mutations. The greatest degree of parallel evolution occurred in the HA receptor and ribonucleocapsid components, polymerase subunits (PB1, PB2, PA and NP. Mutations occurred in host nuclear trafficking factor binding sites as well as sites of virus-virus protein subunit interaction for NP, NS1, HA and NA proteins. Adaptive regions included cap binding and endonuclease domains in the PB2 and PA polymerase subunits. Four mutations in NS1 resulted in loss of binding to the host cleavage and polyadenylation specificity factor (CPSF30 suggesting that a reduction in inhibition of host gene expression was being selected. The most prevalent mutations in PB2 and NP were shown to increase virulence but differed in their ability to enhance replication and demonstrated epistatic effects. Several positively selected RNA polymerase mutations demonstrated increased virulence associated with >300% enhanced polymerase activity. Adaptive mutations that control host range and virulence were identified by their repeated selection to comprise a defined model for
Varsha Rani Gilhare; Hirpurkar, S. D.; Ashish Kumar; Surendra Kumar Naik; Tarini Sahu
Aim: 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. Materials and Methods: 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 ...
Heymann, David L; Chen, Lincoln; Takemi, Keizo; Fidler, David P; Tappero, Jordan W; Thomas, Mathew J; Kenyon, Thomas A; Frieden, Thomas R; Yach, Derek; Nishtar, Sania; Kalache, Alex; Olliaro, Piero L; Horby, Peter; Torreele, Els; Gostin, Lawrence O; Ndomondo-Sigonda, Margareth; Carpenter, Daniel; Rushton, Simon; Lillywhite, Louis; Devkota, Bhimsen; Koser, Khalid; Yates, Rob; Dhillon, Ranu S; Rannan-Eliya, Ravi P
The Ebola virus disease outbreak in West Africa was unprecedented in both its scale and impact. Out of this human calamity has come renewed attention to global health security--its definition, meaning, and the practical implications for programmes and policy. For example, how does a government begin to strengthen its core public health capacities, as demanded by the International Health Regulations? What counts as a global health security concern? In the context of the governance of global health, including WHO reform, it will be important to distil lessons learned from the Ebola outbreak. The Lancet invited a group of respected global health practitioners to reflect on these lessons, to explore the idea of global health security, and to offer suggestions for next steps. Their contributions describe some of the major threats to individual and collective human health, as well as the values and recommendations that should be considered to counteract such threats in the future. Many different perspectives are proposed. Their common goal is a more sustainable and resilient society for human health and wellbeing. PMID:25987157
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
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: email@example.com [Institut für Biomaterialien und biomolekulare Systeme, Abteilung für Molekularbiologie und Virologie der Pflanzen, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart (Germany)
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.
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.
Adam L Bailey
Full Text Available Key biological properties such as high genetic diversity and high evolutionary rate enhance the potential of certain RNA viruses to adapt and emerge. Identifying viruses with these properties in their natural hosts could dramatically improve disease forecasting and surveillance. Recently, we discovered two novel members of the viral family Arteriviridae: simian hemorrhagic fever virus (SHFV-krc1 and SHFV-krc2, infecting a single wild red colobus (Procolobus rufomitratus tephrosceles in Kibale National Park, Uganda. Nearly nothing is known about the biological properties of SHFVs in nature, although the SHFV type strain, SHFV-LVR, has caused devastating outbreaks of viral hemorrhagic fever in captive macaques. Here we detected SHFV-krc1 and SHFV-krc2 in 40% and 47% of 60 wild red colobus tested, respectively. We found viral loads in excess of 10(6-10(7 RNA copies per milliliter of blood plasma for each of these viruses. SHFV-krc1 and SHFV-krc2 also showed high genetic diversity at both the inter- and intra-host levels. Analyses of synonymous and non-synonymous nucleotide diversity across viral genomes revealed patterns suggestive of positive selection in SHFV open reading frames (ORF 5 (SHFV-krc2 only and 7 (SHFV-krc1 and SHFV-krc2. Thus, these viruses share several important properties with some of the most rapidly evolving, emergent RNA viruses.
Baeten, Jared M; Reid, Stewart E; Delany-Moretlwe, Sinead; Hughes, James P; Wang, Richard S; Wilcox, Ellen; Limbada, Mohammed; Akpomiemie, Godspower; Corey, Lawrence; Wald, Anna; Celum, Connie
In a randomized trial among African women with recurrent genital herpes, episodic acyclovir therapy resulted in modestly greater likelihood of lesion healing (hazard ratio [HR] = 1.48, P = 0.098; mean, 5.1 vs. 6.0 days) and cessation of herpes simplex virus shedding (HR = 1.88, P = 0.008; mean, 3.0 vs. 5.0 days) compared with placebo, similar to results of studies in high-income countries (ClinicalTrials.gov registration NCT00808405).
Song, Sharon; Johnson, Matthew; Harris, Aaron M.; Kaufman, Gary I.; Freedman, David; Quinn, Michael T.; Kim, Karen E.
Introduction Most research on hepatitis B virus (HBV) infection in the United States is limited to Asian populations, despite an equally high prevalence among African immigrants. The purpose of this study was to determine testing and detection rates of HBV infection among African-born people residing in the Chicago metropolitan area. Methods A hepatitis education and prevention program was developed in collaboration with academic, clinical, and community partners for immigrant and refugee populations at risk for HBV infection. Community health workers implemented chain referral sampling, a novel strategy for recruiting hard-to-reach participants, targeting African-born participants. Participants were tested in both clinical and nonclinical settings. To assess infection status, blood samples were obtained for hepatitis B surface antigen (HBsAg), core antibody, and surface antibody testing. Demographic information was collected on age, sex, health insurance status, country of origin, and years residing in the United States. Participants were notified of testing results, and HBsAg-positive participants were referred for follow-up medical care. Results Of 1,000 African-born people who received education, 445 (45%) agreed to participate in HBV screening. There were 386 (87%) participants tested in clinical and 59 (13%) tested in nonclinical sites. Compared with participants who were tested in clinical settings, participants tested in nonclinical settings were older, were less likely to have health insurance, and had lived in the United States longer (P Somalia (11%), or Ethiopia (10%). There were 35 (8%) HBsAg-positive people, 37% had evidence of past infection, and 29% were immune. Conclusions Chain referral sampling identified many at-risk African-born people with chronic HBV infection. The large proportion of HBsAg-positive people in this sample reinforces the need for health promotion programs that are culturally appropriate and community-driven. PMID:27584874
Song, Sharon; Johnson, Matthew; Harris, Aaron M.; Kaufman, Gary I.; Freedman, David; Quinn, Michael T.; Kim, Karen E.
Introduction Most research on hepatitis B virus (HBV) infection in the United States is limited to Asian populations, despite an equally high prevalence among African immigrants. The purpose of this study was to determine testing and detection rates of HBV infection among African-born people residing in the Chicago metropolitan area. Methods A hepatitis education and prevention program was developed in collaboration with academic, clinical, and community partners for immigrant and refugee populations at risk for HBV infection. Community health workers implemented chain referral sampling, a novel strategy for recruiting hard-to-reach participants, targeting African-born participants. Participants were tested in both clinical and nonclinical settings. To assess infection status, blood samples were obtained for hepatitis B surface antigen (HBsAg), core antibody, and surface antibody testing. Demographic information was collected on age, sex, health insurance status, country of origin, and years residing in the United States. Participants were notified of testing results, and HBsAg-positive participants were referred for follow-up medical care. Results Of 1,000 African-born people who received education, 445 (45%) agreed to participate in HBV screening. There were 386 (87%) participants tested in clinical and 59 (13%) tested in nonclinical sites. Compared with participants who were tested in clinical settings, participants tested in nonclinical settings were older, were less likely to have health insurance, and had lived in the United States longer (P Nigeria (13%), Ghana (11%), Somalia (11%), or Ethiopia (10%). There were 35 (8%) HBsAg-positive people, 37% had evidence of past infection, and 29% were immune. Conclusions Chain referral sampling identified many at-risk African-born people with chronic HBV infection. The large proportion of HBsAg-positive people in this sample reinforces the need for health promotion programs that are culturally appropriate and community
Schønning, Kristian; Lund, O; Lund, O S;
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...... neutralization gradually increased. Virus neutralization by virion aggregation was minimal, as MAb binding to HIV-1 Env did not interfere with an AMLV Env-mediated infection by HIV-1(AMLV/HIV-1) pseudotypes of CD4(-) HEK293 cells. MAb neutralization of chimeric virions could be described as a third...... neutralization of T-cell line-adapted HIV-1 is incremental rather than all or none and that each MAb binding an Env oligomer reduces the likelihood of infection....
Peng, Xiuming; Wu, Haibo; Peng, Xiaorong; Wu, Xiaoxin; Cheng, Linfang; Liu, Fumin; Ji, Shujing; Wu, Nanping
Avian influenza viruses (AIVs) are known to cross species barriers, and emergent highly pathogenic H5N6 AIVs pose a serious threat to human health and the poultry industry. Here, we serially passaged an H5N6 virus 10 times in BALB/c mice. The pathogenicity of the wild-type 6D2 (WT-6D2) and mammal-adapted 6D2 strain (MA-6D2) were compared. The viral titer in multiple organs and the death rate for MA-6D2 were significantly higher than for WT-6D2. We provide evidence that the mutations HA A150V, NA R143K and G147E, PB2 E627K, and PA A343T may be important for adaptation of H5N6 AIVs to mammals. PMID:26997612
Heineman, Richard H.; Brown, Sam P.
Life history theory attempts to account for how organisms lead their lives, balancing the conflicting demands of reproduction and survival. Here, we track the genomic and phenotypic evolution of the bacteriophage virus T7 across a postulated fecundity/longevity constraint. We adapted T7 to a challenging survival environment (6M urea). Our evolved strain displayed a significant improvement in propagule survival, coupled with a significant loss of fecundity (reduced growth rate on host cells). ...
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.
Linda Highfield; Marieke A. Hartman; Patricia Dolan Mullen; Rodriguez, Serena A.; Fernandez, Maria E.; L. Kay Bartholomew
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 re...
Francisco de la Poza
Full Text Available African horse sickness virus (AHSV belongs to the genus Orbivirus. We have now engineered naked DNAs and recombinant modified vaccinia virus Ankara (rMVA expressing VP2 and NS1 proteins from AHSV-4. IFNAR((-/- mice inoculated with DNA/rMVA-VP2,-NS1 from AHSV-4 in an heterologous prime-boost vaccination strategy generated significant levels of neutralizing antibodies specific of AHSV-4. In addition, vaccination stimulated specific T cell responses against the virus. The vaccine elicited partial protection against an homologous AHSV-4 infection and induced cross-protection against the heterologous AHSV-9. Similarly, IFNAR((-/- mice vaccinated with an homologous prime-boost strategy with rMVA-VP2-NS1 from AHSV-4 developed neutralizing antibodies and protective immunity against AHSV-4. Furthermore, the levels of immunity were very high since none of vaccinated animals presented viraemia when they were challenged against the homologous AHSV-4 and very low levels when they were challenged against the heterologous virus AHSV-9. These data suggest that the immunization with rMVA/rMVA was more efficient in protection against a virulent challenge with AHSV-4 and both strategies, DNA/rMVA and rMVA/rMVA, protected against the infection with AHSV-9. The inclusion of the protein NS1 in the vaccine formulations targeting AHSV generates promising multiserotype vaccines.
Borca, Manuel V; O'Donnell, Vivian; Holinka, Lauren G; Rai, Devendra K; Sanford, Brenton; Alfano, Marialexia; Carlson, Jolene; Azzinaro, Paul A; Alonso, Covadonga; Gladue, Douglas P
African swine fever virus (ASFV) is the etiological agent of a contagious and often lethal disease of domestic pigs that has significant economic consequences for the swine industry. The viral genome encodes for more than 150 genes, and only a select few of these genes have been studied in some detail. Here we report the characterization of open reading frame Ep152R that has a predicted complement control module/SCR domain. This domain is found in Vaccinia virus proteins that are involved in blocking the immune response during viral infection. A recombinant ASFV harboring a HA tagged version of the Ep152R protein was developed (ASFV-G-Ep152R-HA) and used to demonstrate that Ep152R is an early virus protein. Attempts to construct recombinant viruses having a deleted Ep152R gene were consistently unsuccessful indicating that Ep152R is an essential gene. Interestingly, analysis of host-protein interactions for Ep152R using a yeast two-hybrid screen, identified BAG6, a protein previously identified as being required for ASFV replication. Furthermore, fluorescent microscopy analysis confirms that Ep152R-BAG6 interaction actually occurs in cells infected with ASFV. PMID:27497620
Reddy, Priscilla; Taylor, Sandra E; Sifunda, Sibusiso
This article examines a partnership between researchers from the United States who are involved in corrections health issues and scientists from South Africa who conduct prison health research, a previously underresearched area in South Africa. The article discusses some of the challenges as well as opportunities for knowledge and skills exchange via capacity building and collaboration strategies. Through historical and contemporary perspectives, it also discusses barriers and benefits of collaboration when forging links between researchers from developed and less developed nations. A focus on conducting public health research in South Africa, and on HIV/AIDS studies in particular, is placed within the context of the 2001 document of the Council on Health Research for Development. The South African prison health study represents a collaborative between the South African National Health Promotion Research and Development Group of the Medical Research Council, the South African Department of Correctional Services, and Emory University in Atlanta, Georgia. The article illuminates the process of adapting a model for a postapartheid prison study from one designed for use in the American correctional system. PMID:12413197
H5N2 highly pathogenic avian influenza (HPAI) viruses caused a severe poultry outbreak in the United States (U.S.) during 2015. In order to examine changes in adaptation of this viral lineage, the infectivity, transmission and pathogenesis of poultry H5N2 viruses was investigated in chickens and mal...
Felicity J Haines
Full Text Available A single-step, multiplex, real-time polymerase chain reaction (RT-PCR was developed for the simultaneous and differential laboratory diagnosis of Classical swine fever virus (CSFV and African swine fever virus (ASFV alongside an exogenous internal control RNA (IC-RNA. Combining a single extraction methodology and primer and probe sets for detection of the three target nucleic acids CSFV, ASFV and IC-RNA, had no effect on the analytical sensitivity of the assay and the new triplex RT-PCR was comparable to standard PCR techniques for CSFV and ASFV diagnosis. After optimisation the assay had a detection limit of 5 CSFV genome copies and 22 ASFV genome copies. Analytical specificity of the triplex assay was validated using a panel of viruses representing 9 of the 11 CSFV subgenotypes, at least 8 of the 22 ASFV genotypes as well as non-CSFV pestiviruses. Positive and negative clinical samples from animals infected experimentally, due to field exposure or collected from the UK which is free from both swine diseases, were used to evaluate the diagnostic sensitivity and specificity for detection of both viruses. The diagnostic sensitivity was 100% for both viruses whilst diagnostic specificity estimates were 100% for CSFV detection and 97.3% for ASFV detection. The inclusion of a heterologous internal control allowed identification of false negative results, which occurred at a higher level than expected. The triplex assay described here offers a valuable new tool for the differential detection of the causative viruses of two clinically indistinguishable porcine diseases, whose geographical occurrence is increasingly overlapping.
Ivanov, Vadim; Efremov, Evgeniy E; Novikov, Boris V; Balyshev, Vladimir M; Tsibanov, Sodnom Zh; Kalinovsky, Tatiana; Kolbasov, Denis V; Niedzwiecki, Aleksandra; Rath, Matthias
Periodic outbreaks of African swine fever virus (ASFV) infection around the world threaten local populations of domestic pigs with lethal disease and provide grounds for pandemic spread. Effective vaccination may bring this threat under control. We investigated the effectiveness of select peptides mimicking viral proteins in establishing a protective immune response. Forty-six synthetic peptides based on the analysis of the complete nucleotide sequence of ASFV were tested for immunogenicity in mice. The 17 best immune response-inducing peptide candidates were selected for further investigation. Twenty-four domestic pigs, 3-4 months old and weighing 20-25 kg, were divided into six groups (n = 4) and immunized by subcutaneous injection using a standard three-round injection protocol with one of four peptide combinations prepared from the 17 peptides (Groups 1-4) or with carrier only (Group 5). Group 6, the control, was not vaccinated. Animal body temperature and behavior were monitored during and post immunization for health assessment. Two weeks after the last round of immunizations, the pigs were infected with live ASFV (Espania 70) at 6.0 Ig GAE50/cm3, and the survival rate was monitored. Blood samples were collected for analysis the day before infection and on days 3, 7 and 10 post-infection, or from deceased animals. The serum titers of specific immunoglobulins against synthetic peptides and whole inactivated ASFV were determined by enzyme immunoassay before and after infection. The presence of viral DNA in blood serum samples was determined by polymerase chain reaction. Viral infection activity in blood sera was determined by heme absorption in cultured porcine bone marrow and porcine leukocyte cells. Repeating the injection of synthetic peptides in both the mice and pigs produced an immune response specific to individual peptides, which differed widely in the intensity scale. Specific anti-whole virus immunoglobulin binding activity in the swine serum samples
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
Christensen-Dalsgaard, Jakob; Brandt, Christian; Wilson, Maria;
responses of five West African lungfish (Protopterus annectens) using brainstem potentials evoked by calibrated sound and vibration stimuli in air and water. We find that the lungfish ear has good low-frequency vibration sensitivity, like recent amphibians, but poor sensitivity to air-borne sound. The skull...
Full Text Available Significant progress has been made in Hepatitis C virus (HCV culture since the JFH1 strain cloning. However, developing efficient and physiologically relevant culture systems for all viral genotypes remains an important goal. In this work, we aimed at producing a high titer JFH1 derived virus to test different hepatic cells' permissivity. To this end, we performed successive infections and obtained a JFH1 derived virus reaching high titers. Six potential adaptive mutations were identified (I599V in E2, R1373Q and M1611T in NS3, S2364P and C2441S in NS5A and R2523K in NS5B and the effect of these mutations on HCV replication and infectious particle production was investigated. This cell culture adapted virus enabled us to efficiently infect primary human hepatocytes, as demonstrated using the RFP-NLS-IPS reporter protein and intracellular HCV RNA quantification. However, the induction of a strong type III interferon response in these cells was responsible for HCV inhibition. The disruption of this innate immune response led to a strong infection enhancement and permitted the detection of viral protein expression by western blotting as well as progeny virus production. This cell culture adapted virus also enabled us to easily compare the permissivity of seven hepatoma cell lines. In particular, we demonstrated that HuH-7, HepG2-CD81, PLC/PRF/5 and Hep3B cells were permissive to HCV entry, replication and secretion even if the efficiency was very low in PLC/PRF/5 and Hep3B cells. In contrast, we did not observe any infection of SNU-182, SNU-398 and SNU-449 hepatoma cells. Using iodixanol density gradients, we also demonstrated that the density profiles of HCV particles produced by PLC/PRF/5 and Hep3B cells were different from that of HuH-7 and HepG2-CD81 derived virions. These results will help the development of a physiologically relevant culture system for HCV patient isolates.
Lakdawala, Seema S; Jayaraman, Akila; Halpin, Rebecca A; Lamirande, Elaine W; Shih, Angela R; Stockwell, Timothy B; Lin, Xudong; Simenauer, Ari; Hanson, Christopher T; Vogel, Leatrice; Paskel, Myeisha; Minai, Mahnaz; Moore, Ian; Orandle, Marlene; Das, Suman R; Wentworth, David E; Sasisekharan, Ram; Subbarao, Kanta
Influenza A viruses pose a major public health threat by causing seasonal epidemics and sporadic pandemics. Their epidemiological success relies on airborne transmission from person to person; however, the viral properties governing airborne transmission of influenza A viruses are complex. Influenza A virus infection is mediated via binding of the viral haemagglutinin (HA) to terminally attached α2,3 or α2,6 sialic acids on cell surface glycoproteins. Human influenza A viruses preferentially bind α2,6-linked sialic acids whereas avian influenza A viruses bind α2,3-linked sialic acids on complex glycans on airway epithelial cells. Historically, influenza A viruses with preferential association with α2,3-linked sialic acids have not been transmitted efficiently by the airborne route in ferrets. Here we observe efficient airborne transmission of a 2009 pandemic H1N1 (H1N1pdm) virus (A/California/07/2009) engineered to preferentially bind α2,3-linked sialic acids. Airborne transmission was associated with rapid selection of virus with a change at a single HA site that conferred binding to long-chain α2,6-linked sialic acids, without loss of α2,3-linked sialic acid binding. The transmissible virus emerged in experimentally infected ferrets within 24 hours after infection and was remarkably enriched in the soft palate, where long-chain α2,6-linked sialic acids predominate on the nasopharyngeal surface. Notably, presence of long-chain α2,6-linked sialic acids is conserved in ferret, pig and human soft palate. Using a loss-of-function approach with this one virus, we demonstrate that the ferret soft palate, a tissue not normally sampled in animal models of influenza, rapidly selects for transmissible influenza A viruses with human receptor (α2,6-linked sialic acids) preference.
The alterations of avian influenza A virus hemagglutinin (HA) H2 as a result of adaptation to mice were first investigated in this study. HA of mouse-adapted (MA) variant was somewhat different from that of the original strain in electrophoretic mobility, antigenic structure and in hemagglutination activity with mouse red blood cells. (author)
Gaudieri, Silvana; Rauch, Andri; Park, Lawrence P; Freitas, Elizabeth; Herrmann, Susan; Jeffrey, Gary; Cheng, Wendy; Pfafferott, Katja; Naidoo, Kiloshni; Chapman, Russell; Battegay, Manuel; Weber, Rainer; Telenti, Amalio; Furrer, Hansjakob; James, Ian; Lucas, Michaela; Mallal, Simon A
Cellular immune responses are an important correlate of hepatitis C virus (HCV) infection outcome. These responses are governed by the host's human leukocyte antigen (HLA) type, and HLA-restricted viral escape mutants are a critical aspect of this host-virus interaction. We examined the driving forces of HCV evolution by characterizing the in vivo selective pressure(s) exerted on single amino acid residues within nonstructural protein 3 (NS3) by the HLA types present in two host populations. Associations between polymorphisms within NS3 and HLA class I alleles were assessed in 118 individuals from Western Australia and Switzerland with chronic hepatitis C infection, of whom 82 (69%) were coinfected with human immunodeficiency virus. The levels and locations of amino acid polymorphisms exhibited within NS3 were remarkably similar between the two cohorts and revealed regions under functional constraint and selective pressures. We identified specific HCV mutations within and flanking published epitopes with the correct HLA restriction and predicted escaped amino acid. Additional HLA-restricted mutations were identified that mark putative epitopes targeted by cell-mediated immune responses. This analysis of host-virus interaction reveals evidence of HCV adaptation to HLA class I-restricted immune pressure and identifies in vivo targets of cellular immune responses at the population level. PMID:17071929
Verdier, M; Denis, F; Leonard, G; Sangare, A; Patillaud, S; Prince-David, M; Essex, M
The effectiveness of four screening tests for detecting antibody to human T-cell leukemia virus type I (HTLV-I) was determined by using 2,700 African serum specimens. The tests studied were indirect immunofluorescence, particle agglutination from Fujirebio, and two enzyme immunoassays, one from Abbott Laboratories that used virus lysate from HUT 102 cells and the other from Cambridge BioScience Corp. that used an env recombinant protein. Positive and doubtful sera were confirmed by Western immunoblot and radioimmunoprecipitation assay with Food and Drug Administration seropositivity criteria. The best results were obtained with the two enzyme immunoassays, which were more sensitive (100 and 98.6% [Abbott and Cambridge, respectively]) and more specific (98.7 and 96.5%). Indirect immunofluorescence exhibited difficulties for reading and interpretation. With particle agglutination, prozone was observed for 9 of 78 HTLV-I-positive serum specimens. False-positives in any of the tests were not linked to cross-reactions with human immunodeficiency viruses. However, confirmation tests remain necessary for HTLV-I screening.
W James Cooper
Full Text Available BACKGROUND: How particular changes in functional morphology can repeatedly promote ecological diversification is an active area of evolutionary investigation. The African rift-lake cichlids offer a calibrated time series of the most dramatic adaptive radiations of vertebrate trophic morphology yet described, and the replicate nature of these events provides a unique opportunity to test whether common changes in functional morphology have repeatedly facilitated their ecological success. METHODOLOGY/PRINCIPAL FINDINGS: Specimens from 87 genera of cichlid fishes endemic to Lakes Tanganyka, Malawi and Victoria were dissected in order to examine the functional morphology of cichlid feeding. We quantified shape using geometric morphometrics and compared patterns of morphological diversity using a series of analytical tests. The primary axes of divergence were conserved among all three radiations, and the most prevalent changes involved the size of the preorbital region of the skull. Even the fishes from the youngest of these lakes (Victoria, which exhibit the lowest amount of skull shape disparity, have undergone extensive preorbital evolution relative to other craniofacial traits. Such changes have large effects on feeding biomechanics, and can promote expansion into a wide array of niches along a bentho-pelagic ecomorphological axis. CONCLUSIONS/SIGNIFICANCE: Here we show that specific changes in trophic anatomy have evolved repeatedly in the African rift lakes, and our results suggest that simple morphological alterations that have large ecological consequences are likely to constitute critical components of adaptive radiations in functional morphology. Such shifts may precede more complex shape changes as lineages diversify into unoccupied niches. The data presented here, combined with observations of other fish lineages, suggest that the preorbital region represents an evolutionary module that can respond quickly to natural selection when fishes
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.
Van Borm, Steven; Rosseel, Toon; Haegeman, Andy; Fana, Mpolokang Elliot; Seoke, Latoa; Hyera, Joseph; Matlho, George; Vandenbussche, Frank; De Clercq, Kris
The complete genome sequences of three foot-and-mouth disease viruses (one virus of each serotype SAT1, SAT2 and O) were directly sequenced from RNA extracted from clinical bovine samples, demonstrating the feasibility of full-genome sequencing from strong positive samples taken from symptomatic animals. PMID:27151795
Lebel, S.; Fleskens, L.; Forster, P.M.; Jackson, L.S.; Lorenz, S.
Stabilizing smallholder crop yields under changing climatic conditions in sub-Saharan Africa will require adaptation strategies focused on soil and water management. Impact studies of climate change on crop yields often ignore the potential of adaptation strategies such as rainwater harvesting (RWH)
Guskey, L E; Jenkin, H M
Baby hamster kidney (BHK-21) cells were adapted to grow in shaker culture using Waymouth medium 752/1 containing 20 mM N-2-hydroxyethyl-piperazine-N'-2'-ethanesulfonic acid buffer and supplemented with 2.5% (vol/vol) calf serum, 0.002% (wt/vol) sodium oleate, and 0.2% fatty acid-free bovine serum albumin (WO2.5). Infectivity of Japanese encephalitis virus grown in the cells adapted to WO2.5 approached 2 x 10(8) plaque-forming units per ml. The culture volume of infected cells was reduced fivefold 12 h after infection. This step resulted in a 10-fold increase in infectivity over that obtained from infected cultures not subjected to volume reduction. PMID:1237269
Full Text Available BACKGROUND: Lethal mutagenesis, or virus extinction promoted by mutagen-induced elevation of mutation rates of viruses, may meet with the problem of selection of mutagen-resistant variants, as extensively documented for standard, non-mutagenic antiviral inhibitors. Previously, we characterized a mutant of foot-and-mouth disease virus that included in its RNA-dependent RNA polymerase replacement M296I that decreased the sensitivity of the virus to the mutagenic nucleoside analogue ribavirin. METHODOLOGY AND PRINCIPAL FINDINGS: Replacement M296I in the viral polymerase impedes the extinction of the mutant foot-and-mouth disease virus by elevated concentrations of ribavirin. In contrast, wild type virus was extinguished by the same ribavirin treatment and, interestingly, no mutants resistant to ribavirin were selected from the wild type populations. Decreases of infectivity and viral load of the ribavirin-resistant M296I mutant were attained with a combination of the mutagen 5-fluorouracil and the non-mutagenic inhibitor guanidine hydrocloride. However, extinction was achieved with a sequential treatment, first with ribavirin, and then with a minimal dose of 5-fluorouracil in combination with guanidine hydrochloride. Both, wild type and ribavirin-resistant mutant M296I exhibited equal sensitivity to this combination, indicating that replacement M296I in the polymerase did not confer a significant cross-resistance to 5-fluorouracil. We discuss these results in relation to antiviral designs based on lethal mutagenesis. CONCLUSIONS: (i When dominant in the population, a mutation that confers partial resistance to a mutagenic agent can jeopardize virus extinction by elevated doses of the same mutagen. (ii A wild type virus, subjected to identical high mutagenic treatment, need not select a mutagen-resistant variant, and the population can be extinguished. (iii Extinction of the mutagen-resistant variant can be achieved by a sequential treatment of a
Bargatze, L. F.
Active Data Archive Product Tracking (ADAPT) is a collection of software routines that permits one to generate XML metadata files to describe and register data products in support of the NASA Heliophysics Virtual Observatory VxO effort. ADAPT is also a philosophy. The ADAPT concept is to use any and all available metadata associated with scientific data to produce XML metadata descriptions in a consistent, uniform, and organized fashion to provide blanket access to the full complement of data stored on a targeted data server. In this poster, we present an application of ADAPT to describe all of the data products that are stored by using the Common Data File (CDF) format served out by the CDAWEB and SPDF data servers hosted at the NASA Goddard Space Flight Center. These data servers are the primary repositories for NASA Heliophysics data. For this purpose, the ADAPT routines have been used to generate data resource descriptions by using an XML schema named Space Physics Archive, Search, and Extract (SPASE). SPASE is the designated standard for documenting Heliophysics data products, as adopted by the Heliophysics Data and Model Consortium. The set of SPASE XML resource descriptions produced by ADAPT includes high-level descriptions of numerical data products, display data products, or catalogs and also includes low-level "Granule" descriptions. A SPASE Granule is effectively a universal access metadata resource; a Granule associates an individual data file (e.g. a CDF file) with a "parent" high-level data resource description, assigns a resource identifier to the file, and lists the corresponding assess URL(s). The CDAWEB and SPDF file systems were queried to provide the input required by the ADAPT software to create an initial set of SPASE metadata resource descriptions. Then, the CDAWEB and SPDF data repositories were queried subsequently on a nightly basis and the CDF file lists were checked for any changes such as the occurrence of new, modified, or deleted
Lelli, Rossella; Molini, Umberto; Ronchi, Gaetano Federico; Rossi, Emanuela; Franchi, Paola; Ulisse, Simonetta; Armillotta, Gisella; Capista, Sara; Khaiseb, Siegfried; Di Ventura, Mauro; Pini, Attilio
African horse sickness (AHS) is a non-contagious viral disease of solipeds transmitted by Culicoides. The disease is endemic in most African countries. Past experience has shown that Italy is a country exposed to emerging infectious diseases endemic to Africa; an incursion of AHS virus together with the widespread presence of Culicoides vectors could be the cause of a serious epidemic emergency. A live attenuated vaccine containing seven of the nine viral serotypes, serotype 5 and 9 are excluded, is commercially available from Onderstepoort Biological Products. However, the use of live vaccines is a matter of endless disputes, and therefore inactivated or recombinant alternative products have been investigated over the years. Since research on AHS is hampered by the use of horses to evaluate vaccine potency, in a previous experiment serological response to serotypes 5 and 9 was assayed in guinea-pigs and horses. A durable and comparable serological response was observed in the two animal species. In the present study antibody response in horses and guinea-pigs, immunised with the inactivated-adjuvanted vaccine formulated with serotype 9, was tested over a period of 12 months. When immunity was challenged, horses were protected from infection and disease. Antibody response in horses and guinea-pigs compared favourably.
Zúñiga, Martha C
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. PMID:12297325
Richard H Heineman
Full Text Available Life history theory attempts to account for how organisms lead their lives, balancing the conflicting demands of reproduction and survival. Here, we track the genomic and phenotypic evolution of the bacteriophage virus T7 across a postulated fecundity/longevity constraint. We adapted T7 to a challenging survival environment (6M urea. Our evolved strain displayed a significant improvement in propagule survival, coupled with a significant loss of fecundity (reduced growth rate on host cells. However, the increased resistance to urea did not generalise to increased resistance against temperature stress, highlighting that propagule durability is environment dependent. Previous comparative studies predicted that changes in propagule resistance would be mediated by changes in capsid proteins or gene deletions. In contrast, we found that point mutations in internal core protein genes (6.7 and 16 were responsible for the increased urea resistance of our evolved strain. Prior to the emergence of the 6.7 and 16 mutations, a distinct set of 5-point mutations peaked at over 20% prevalence before attenuating, suggestive of negative epistatic interactions during adaptation. Our results illustrate that parasites can adapt to specific transmission environments, and that this adaptation can impose costs on the subsequent ability to exploit host cells, potentially constraining durable parasites to lower virulence.
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
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.
K. Kondiah; Albertyn, J; R.R. Bragg
Psittacine beak and feather disease (PBFD) is a common viral disease of wild and captive psittacine birds characterized by symmetric feather loss and beak deformities. The causative agent, beak and feather disease virus (BFDV), is a small, circular single-stranded DNA virus that belongs to the genus Circovirus. BFDV can be detected by PCR or the use of haemagglutination (HA) and haemagglutination inhibition (HI) assays that detect antigen and antibodies respectively. Erythrocytes from ...
Rockx, Barry; Bossart, Katharine N.; Feldmann, Friederike; Geisbert, Joan B.; Hickey, Andrew C.; Brining, Douglas; Callison, Julie; Safronetz, David; Marzi, Andrea; Kercher, Lisa; Long, Dan; Broder, Christopher C.; Feldmann, Heinz; Geisbert, Thomas W
The henipaviruses, Hendra virus (HeV) and Nipah virus (NiV), are emerging zoonotic paramyxoviruses that can cause severe and often lethal neurologic and/or respiratory disease in a wide variety of mammalian hosts, including humans. There are presently no licensed vaccines or treatment options approved for human or veterinarian use. Guinea pigs, hamsters, cats, and ferrets, have been evaluated as animal models of human HeV infection, but studies in nonhuman primates (NHP) have not been reporte...
Full Text Available Avian influenza viruses (AIVs have been pivotal to the origination of human pandemic strains. Despite their scientific and public health significance, however, there remains much to be understood about the ecology and evolution of AIVs in wild birds, where major pools of genetic diversity are generated and maintained. Here, we present comparative phylodynamic analyses of human and AIVs in North America, demonstrating (i significantly higher standing genetic diversity and (ii phylogenetic trees with a weaker signature of immune escape in AIVs than in human viruses. To explain these differences, we performed statistical analyses to quantify the relative contribution of several potential explanations. We found that HA genetic diversity in avian viruses is determined by a combination of factors, predominantly subtype-specific differences in host immune selective pressure and the ecology of transmission (in particular, the durability of subtypes in aquatic environments. Extending this analysis using a computational model demonstrated that virus durability may lead to long-term, indirect chains of transmission that, when coupled with a short host lifespan, can generate and maintain the observed high levels of genetic diversity. Further evidence in support of this novel finding was found by demonstrating an association between subtype-specific environmental durability and predicted phylogenetic signatures: genetic diversity, variation in phylogenetic tree branch lengths, and tree height. The conclusion that environmental transmission plays an important role in the evolutionary biology of avian influenza viruses-a manifestation of the "storage effect"-highlights the potentially unpredictable impact of wildlife reservoirs for future human pandemics and the need for improved understanding of the natural ecology of these viruses.
Kamol Suwannakarn; Apiradee Theamboonlers; Yong Poovorawan
Objective:To understand the epidemiology of the East, Central and South African(ECSA) genotype of Chikungunya virus(CHIKV)in terms of emerging and re-emerging infections, this study has been aimed at investigating the evolutionary parameters, genomic signatures and molecular tracking of theCHIKV ECSA genotype in South-east Asia and coastal areas of the Indian Ocean between 2006 and 2009 by using phylogenetic analysis and the Bayesian Markov Chain Monte Carlo (BMCMC) evolutionary estimation.Methods: Nearly complete genome sequences of53 CHIKV isolates from all genotypes were subjected to phylogenetic analysis and evolutionary parameter estimation. The amino acids of67of ECSA genotype during2006 to2009 were compared for finding molecular signature tracking. The ECSA genotype signatures were visualized to find the possible transmission root was projected onto a geographic map.Results:Phylogenetic analysis showed theECSA genotype was divided into2 groups. The first group comprises viruses from India and Southeast Asian countries. The second group consists of strains typically circulating in Sri Lanka in2008. The evolutionary parameters of these groups depicted the time of the most recent common ancestor at approximately 7.5years ago. The genomic signatures revealed the positions of amino acid variation in each group.Conclusions:The molecular evolution projected onto a geographical map showed the routes ofCHIKVtransmission from 2006 to2009. Molecular tracking will assist in understanding transmission routes, epidemiology and molecular evolution ofCHIKV.
Full Text Available Abstract Background Geminiviruses mainly infect terminally differentiated tissues and cells in plants. They need to reprogramme host cellular machinery for DNA replication. This process is thought to be mediated by inactivation of cell-cycle repressor proteins and by induction of host DNA synthesis protein expression through actions of the geminviral replication initiator protein (Rep. Findings Exploiting a Nicotiana benthamiana pOri2 line, which is transformed with a transgene consisting of a direct repeat of the African cassava mosaic virus (ACMV-replication origin (Ori flanking a non-viral DNA region, and virus-induced RNA silencing (VIGS, the impact of host gene expression on replication of the ACMV-derived replicon was investigated. The ACMV Rep trans-replicated the viral episomal replicon in leaves of young but not older pOri2 plants. Upon VIGS-mediated down-regulation of N. benthamiana NbRBR1, the retinoblastoma-related protein gene coding for a negative cell-cycle suppressor, recovered the ability of ACMV Rep for trans DNA replication, whereas the silencing of NbPCNA coding for the sliding clamp of DNA polymerase had no effect. Conclusions These results suggest that the cellular machinery for DNA replication in differentiated tissues of older leaves cannot be reprogrammed by Rep alone but may need other uncharacterised viral and plant factors.
Xiao, Chencheng; Ma, Wenjun; Sun, Na; Huang, Lihong; Li, Yaling; Zeng, Zhaoyong; Wen, Yijun; Zhang, Zaoyue; Li, Huanan; Li, Qian; Yu, Yuandi; Zheng, Yi; Liu, Shukai; Hu, Pingsheng; Zhang, Xu; Ning, Zhangyong; Qi, Wenbao; Liao, Ming
Human infections with avian influenza H7N9 or H10N8 viruses have been reported in China, raising concerns that they might cause human epidemics and pandemics. However, how these viruses adapt to mammalian hosts is unclear. Here we show that besides the commonly recognized viral polymerase subunit PB2 residue 627 K, other residues including 87E, 292 V, 340 K, 588 V, 648 V, and 676 M in PB2 also play critical roles in mammalian adaptation of the H10N8 virus. The avian-origin H10N8, H7N9, and H9N2 viruses harboring PB2-588 V exhibited higher polymerase activity, more efficient replication in mammalian and avian cells, and higher virulence in mice when compared to viruses with PB2-588 A. Analyses of available PB2 sequences showed that the proportion of avian H9N2 or human H7N9 influenza isolates bearing PB2-588 V has increased significantly since 2013. Taken together, our results suggest that the substitution PB2-A588V may be a new strategy for an avian influenza virus to adapt mammalian hosts. PMID:26782141
Angela De Jong
Full Text Available Although HIV occurs in all social groups in South African society, certain populations are more vulnerable to HIV through risky behaviour patterns. Of relevance to the present study are the high risk situations that deployed soldiers are exposed to. Three issues indicated the necessity for a study of this kind to be conducted; (a the statistics pointing to a higher incidence of HIV infections among military personnel than among the general population, (b military personnel’s unique vulnerability profile, and (c the South African National Defence Force’s (SANDF increasing participation in international peacekeeping missions. The knowledge, attitudes and practices concerning HIV/AIDS of deployed soldiers were analysed. Results indicated that soldiers were taking sexual risks, although they had high levels of knowledge and had healthy attitudes concerning HIV/AIDS.
Ekue, N F; Wilkinson, P J
No evidence for the presence of soft ticks of the Ornithodoros moubata complex was found during a survey of African swine fever carried out between 1985 and 1988 in the West Province and southern parts of the North West and South West Provinces of Cameroon. The survey consisted of interviews of veterinary assistants and farmers, distribution of a questionnaire and tick searches both manually and with carbon dioxide traps. The absence of warthogs (Phacochoerus aethiopicus) from these areas was also recorded. PMID:2371751
Vandamme, A M; Salemi, M; Van Brussel, M; Liu, H F; Van Laethem, K; Van Ranst, M; Michels, L; Desmyter, J; Goubau, P
We identified a potential new subtype within human T-cell lymphotropic virus type 2 (HTLV-2), HTLV-2d, present in members of an isolated Efe Bambuti Pygmy tribe. Two of 23 Efe Pygmies were HTLV-2 seropositive, with HTLV-2 Western blot and enzyme-linked immunosorbent assay reactivities. From one of them the entire genome of the HTLV-2 strain Efe2 could be amplified and sequenced. In all gene regions analyzed, this strain was the most divergent HTLV-2 strain, differing by 2.4% (tax/rex) to 10.7% (long terminal repeat) from both subtypes HTLV-2a and HTLV-2b, yet major functional elements are conserved. The similarity between the HTLV-2 Efe2 Gag and Env proteins and the corresponding HTLV-2a and -2b proteins is consistent with the observed serological reactivity. In the proximal pX region, one of the two alternative splice acceptor sites is abolished in HTLV-2 Efe2. Another interesting feature of this potential new subtype is that it has a Tax protein of 344 amino acids (aa), which is intermediate in length between the HTLV-2a Tax protein (331 aa) and the HTLV-2b and -2c Tax proteins (356 aa) and similar to the simian T-cell lymphotropic virus type 2 (STLV-2) PP1664 Tax protein. Together these two findings suggest a different phenotype for the HTLV-2 Efe2 strain. Phylogenetic analyses confirmed that the Pygmy Efe2 strain potentially belonged to a new and quite divergent subtype, HTLV-2d. When the STLV-2 bonobo viruses PP1664 and PanP were used as an outgroup, it was clear that the Pygmy HTLV-2 Efe2 strain had the longest independent evolution and that HTLV-2 evolution is consistent with an African origin.
Vandamme, Anne-Mieke; Salemi, Marco; Van Brussel, Marianne; Liu, Hsin-Fu; Van Laethem, Kristel; Van Ranst, Marc; Michels, Ludovic; Desmyter, Jan; Goubau, Patrick
We identified a potential new subtype within human T-cell lymphotropic virus type 2 (HTLV-2), HTLV-2d, present in members of an isolated Efe Bambuti Pygmy tribe. Two of 23 Efe Pygmies were HTLV-2 seropositive, with HTLV-2 Western blot and enzyme-linked immunosorbent assay reactivities. From one of them the entire genome of the HTLV-2 strain Efe2 could be amplified and sequenced. In all gene regions analyzed, this strain was the most divergent HTLV-2 strain, differing by 2.4% (tax/rex) to 10.7% (long terminal repeat) from both subtypes HTLV-2a and HTLV-2b, yet major functional elements are conserved. The similarity between the HTLV-2 Efe2 Gag and Env proteins and the corresponding HTLV-2a and -2b proteins is consistent with the observed serological reactivity. In the proximal pX region, one of the two alternative splice acceptor sites is abolished in HTLV-2 Efe2. Another interesting feature of this potential new subtype is that it has a Tax protein of 344 amino acids (aa), which is intermediate in length between the HTLV-2a Tax protein (331 aa) and the HTLV-2b and -2c Tax proteins (356 aa) and similar to the simian T-cell lymphotropic virus type 2 (STLV-2) PP1664 Tax protein. Together these two findings suggest a different phenotype for the HTLV-2 Efe2 strain. Phylogenetic analyses confirmed that the Pygmy Efe2 strain potentially belonged to a new and quite divergent subtype, HTLV-2d. When the STLV-2 bonobo viruses PP1664 and PanP were used as an outgroup, it was clear that the Pygmy HTLV-2 Efe2 strain had the longest independent evolution and that HTLV-2 evolution is consistent with an African origin. PMID:9557723
Quembo, C J; Jori, F; Heath, L; Pérez-Sánchez, R; Vosloo, W
An epidemiological study of African swine fever (ASF) was conducted between March 2006 and September 2007 in a rural area adjacent to the Gorongosa National park (GNP) located in the Central Mozambique. Domestic pigs and warthogs were sampled to determine the prevalence of antibodies against ASF virus and the salivary antigens of Ornithodoros spp. ticks, while ticks collected from pig pens were tested for the presence of ASFV. In addition, 310 framers were interviewed to gain a better understanding of the pig value chain and potential practices that could impact on the spread of the virus. The sero-prevalence to ASFV was 12.6% on farms and 9.1% in pigs, while it reached 75% in warthogs. Approximately 33% of pigs and 78% of warthogs showed antibodies against salivary antigens of ticks. The differences in sero-prevalence between farms close to the GNP, where there is greater chance for the sylvatic cycle to cause outbreaks, and farms located in the rest of the district, where pig to pig transmission is more likely to occur, were marginally significant. Ornithodoros spp. ticks were found in only 2 of 20 pig pens outside the GNP, and both pens had ticks testing positive for ASFV DNA. Interviews carried out among farmers indicated that biosecurity measures were mostly absent. Herd sizes were small with pigs kept in a free-ranging husbandry system (65%). Only 1.6% of farmers slaughtered on their premises, but 51% acknowledged allowing visitors into their farms to purchase pigs. ASF outbreaks seemed to have a severe economic impact with nearly 36% of farmers ceasing pig farming for at least 1 year after a suspected ASF outbreak. This study provides the first evidence of the existence of a sylvatic cycle in Mozambique and confirms the presence of a permanent source of virus for the domestic pig value chain. PMID:25483914
Considered is the coarse-grained modeling of icosahedral viruses in terms of a three-dimensional lattice (the digital modeling lattice) selected among the projected points in space of a six-dimensional icosahedral lattice. Backbone atomic positions (Cα's for the residues of the capsid and phosphorus atoms P for the genome nucleotides) are then indexed by their nearest lattice point. This leads to a fine-grained lattice point characterization of the full viral chains in the backbone approximation (denoted as digital modeling). Coarse-grained models then follow by a proper selection of the indexed backbone positions, where for each chain one can choose the desired coarseness. This approach is applied to three viruses, the Satellite tobacco mosaic virus, the bacteriophage MS2 and the Pariacoto virus, on the basis of structural data from the Brookhaven Protein Data Bank. In each case the various stages of the procedure are illustrated for a given coarse-grained model and the corresponding indexed positions are listed. Alternative coarse-grained models have been derived and compared. Comments on related results and approaches, found among the very large set of publications in this field, conclude this article. PMID:27126109
Chen, Y.K; Goldbach, R.W.; Prins, M.W.
In four distinct alstroemeria-infecting cucumber mosaic virus (CMV) isolates, additional sequences of various lengths were present in the 3′ nontranslated regions of their RNAs 2 and 3, apparently the result of intra- and intermolecular recombination events. Competition experiments revealed that these recombined RNA 2 and 3 segments increased the biological fitness of CMV in alstroemeria.
Chen, Yuh-Kun; Goldbach, Rob; Prins, Marcel
In four distinct alstroemeria-infecting cucumber mosaic virus (CMV) isolates, additional sequences of various lengths were present in the 3' nontranslated regions of their RNAs 2 and 3, apparently the result of intra- and intermolecular recombination events. Competition experiments revealed that these recombined RNA 2 and 3 segments increased the biological fitness of CMV in alstroemeria. PMID:11907253
Li, Yan; Wang, Ruirui; Du, Xiaogang; Zhang, Mingwang; Xie, Meng
Hepatitis C virus (HCV) is a major cause of liver disease and has been estimated to infect approximately 2%-3% of the world's population. HCV genotype 1 is the subject of intense research and clinical investigations because of its worldwide prevalence and poor access to treatment for patients in developing countries and marginalized populations. The predominant subtypes 1a and 1b of HCV genotype 1 present considerable differences in epidemiological features. However, the genetic signature underlying such phenotypic functional divergence is still an open question. Here, we performed a genome-wide evolutionary study on HCV subtypes 1a and 1b. The results show that adaptive selection has driven the diversification between these subtypes. Furthermore, the major adaptive divergence-related changes have occurred on proteins E1, NS4B, NS5A, and NS5B. Structurally, a number of adaptively selected sites cluster in functional regions potentially relevant to (i) membrane attachment and (ii) the interactions with viral and host cell factors and the genome template. These results might provide helpful hints about the molecular determinants of epidemiological divergence between HCV 1a and 1b.
Justin M Richner
Full Text Available Impaired immune responses in the elderly lead to reduced vaccine efficacy and increased susceptibility to viral infections. Although several groups have documented age-dependent defects in adaptive immune priming, the deficits that occur prior to antigen encounter remain largely unexplored. Herein, we identify novel mechanisms for compromised adaptive immunity that occurs with aging in the context of infection with West Nile virus (WNV, an encephalitic flavivirus that preferentially causes disease in the elderly. An impaired IgM and IgG response and enhanced vulnerability to WNV infection during aging was linked to delayed germinal center formation in the draining lymph node (DLN. Adoptive transfer studies and two-photon intravital microscopy revealed a decreased trafficking capacity of donor naïve CD4+ T cells from old mice, which manifested as impaired T cell diapedesis at high endothelial venules and reduced cell motility within DLN prior to antigen encounter. Furthermore, leukocyte accumulation in the DLN within the first few days of WNV infection or antigen-adjuvant administration was diminished more generally in old mice and associated with a second aging-related defect in local cytokine and chemokine production. Thus, age-dependent cell-intrinsic and environmental defects in the DLN result in delayed immune cell recruitment and antigen recognition. These deficits compromise priming of early adaptive immune responses and likely contribute to the susceptibility of old animals to acute WNV infection.
Franke, A.C.; Haverkort, A.J.; Steyn, J.M.
This study aims to assess the risks and opportunities posed by climate change to potato growers in South Africa and to evaluate adaptation measures in the form of changes in planting time growers could adopt to optimise land and water use efficiencies in potato, using a climate model of past, presen
Hamann, Ilse; Arnault, Joel; Bliefernicht, Jan; Klein, Cornelia; Heinzeller, Dominikus; Kunstmann, Harald
Changing climate and hydro-meteorological boundary conditions are among the most severe challenges to Africa in the 21st century. In particular West Africa faces an urgent need to develop effective adaptation and mitigation strategies to cope with negative impacts on humans and environment due to climate change, increased hydro-meteorological variability and land use changes. To help meet these challenges, the German Federal Ministry of Education and Research (BMBF) started an initiative with institutions in Germany and West African countries to establish together a West African Science Service Center on Climate Change and Adapted Land Use (WASCAL). This activity is accompanied by an establishment of trans-boundary observation networks, an interdisciplinary core research program and graduate research programs on climate change and related issues for strengthening the analytical capabilities of the Science Service Center. A key research activity of the WASCAL Competence Center is the provision of regional climate simulations in a fine spatio-temporal resolution for the core research sites of WASCAL for the present and the near future. The climate information is needed for subsequent local climate impact studies in agriculture, water resources and further socio-economic sectors. The simulation experiments are performed using regional climate models such as COSMO-CLM, RegCM and WRF and statistical techniques for a further refinement of the projections. The core research sites of WASCAL are located in the Sudanian Savannah belt in Northern Ghana, Southern Burkina Faso and Northern Benin. The climate in this region is semi-arid with six rainy months. Due to the strong population growth in West Africa, many areas of the Sudanian Savannah have been already converted to farmland since the majority of the people are living directly or indirectly from the income produced in agriculture. The simulation experiments of the Competence Center and the Core Research Program are
Paul, Satyakama; Marwala, Tshilidzi
South Africa assumes a significant position in the insurance landscape of Africa. The present research based upon qualitative and quantitative analysis, shows that it shows the characteristics of a Complex Adaptive System. In addition, a statistical analysis of risk measures through Value at risk and Conditional tail expectation is carried out to show how an individual insurance company copes under external complexities. The authors believe that an explanation of the coping strategies, and the subsequent managerial implications would enrich our understanding of complexity in business.
Martínez, M A; Carrillo, C; González-candelas, F; Moya, A.; Domingo, E; Sobrino, F
We document the rapid alteration of fitness of two foot-and-mouth disease virus (FMDV) mutants resistant to a neutralizing monoclonal antibody. Both mutants showed a selective disadvantage in BHK-21 cells when passaged in competition with their parental FMDV. Upon repeated replication of the mutants alone, they acquired a selective advantage over the parental FMDV and fixed additional genomic substitutions without reversion of the monoclonal antibody-resistant phenotype. Thus, variants that w...
Full Text Available The role of variable regions of HIV-1 gp120 in immune escape of HIV has been investigated. However, there is scant information on how conserved gp120 regions contribute to virus escaping. Here we have studied how molecular sequence characteristics of conserved C3, C4 and V3 regions of clade C HIV-1 gp120 that are involved in HIV entry and are target of the immune response, are modulated during the disease course. We found an increase of "shifting" putative N-glycosylation sites (PNGSs in the α2 helix (in C3 and in C4 and an increase of sites under positive selection pressure in the α2 helix during the chronic stage of disease. These sites are close to CD4 and to co-receptor binding sites. We also found a negative correlation between electric charges of C3 and V4 during the late stage of disease counteracted by a positive correlation of electric charges of α2 helix and V5 during the same stage. These data allow us to hypothesize possible mechanisms of virus escape involving constant and variable regions of gp120. In particular, new mutations, including new PNGSs occurring near the CD4 and CCR5 binding sites could potentially affect receptor binding affinity and shield the virus from the immune response.
Fomsgaard, Anders; Müller-Trutwin, Michaela C.; Diop, Ousmane;
An apparent species-specific relatedness of SIVagm suggests a coevolution with their natural hosts. However, the exact species or subspecies classification of African green monkeys, AGM, is uncertain because current classification schemes rely on phenotype markers, while more definitive genetic...... data are lacking. In this study, the CD4 protein involved in tissue type recognition was gentically cloned and sequence from PBMC RNA from all AGM species, including Barbados green monkeys (BGM). Phylogenetic trees were constructed that also included genomic CD4 nucleotide sequences from patas, sooty...
Giménez-Lirola, Luis G; Mur, Lina; Rivera, Belen; Mogler, Mark; Sun, Yaxuan; Lizano, Sergio; Goodell, Christa; Harris, D L Hank; Rowland, Raymond R R; Gallardo, Carmina; Sánchez-Vizcaíno, José Manuel; Zimmerman, Jeff
In the absence of effective vaccine(s), control of African swine fever caused by African swine fever virus (ASFV) must be based on early, efficient, cost-effective detection and strict control and elimination strategies. For this purpose, we developed an indirect ELISA capable of detecting ASFV antibodies in either serum or oral fluid specimens. The recombinant protein used in the ELISA was selected by comparing the early serum antibody response of ASFV-infected pigs (NHV-p68 isolate) to three major recombinant polypeptides (p30, p54, p72) using a multiplex fluorescent microbead-based immunoassay (FMIA). Non-hazardous (non-infectious) antibody-positive serum for use as plate positive controls and for the calculation of sample-to-positive (S:P) ratios was produced by inoculating pigs with a replicon particle (RP) vaccine expressing the ASFV p30 gene. The optimized ELISA detected anti-p30 antibodies in serum and/or oral fluid samples from pigs inoculated with ASFV under experimental conditions beginning 8 to 12 days post inoculation. Tests on serum (n = 200) and oral fluid (n = 200) field samples from an ASFV-free population demonstrated that the assay was highly diagnostically specific. The convenience and diagnostic utility of oral fluid sampling combined with the flexibility to test either serum or oral fluid on the same platform suggests that this assay will be highly useful under the conditions for which OIE recommends ASFV antibody surveillance, i.e., in ASFV-endemic areas and for the detection of infections with ASFV isolates of low virulence. PMID:27611939
O'Donnell, Vivian; Holinka, Lauren G; Sanford, Brenton; Krug, Peter W; Carlson, Jolene; Pacheco, Juan M; Reese, Bo; Risatti, Guillermo R; Gladue, Douglas P; Borca, Manuel V
African swine fever virus (ASFV) produces a contagious disease of domestic pigs that results in severe economic consequences to the swine industry. Control of the disease has been hampered by the unavailability of vaccines. We recently reported the development of two experimental vaccine strains (ASFV-G-Δ9GL and ASFV-G-ΔMGF) based on the attenuation of the highly virulent and epidemiologically relevant Georgia2007 isolate. Deletion of the 9GL gene or six genes of the MGF360/505 group produced two attenuated ASFV strains which were able to confer protection to animals when challenged with the virulent parental virus. Both viruses, although efficient in inducing protection, present concerns regarding their safety. In an attempt to solve this problem we developed a novel virus strain, ASFV-G-Δ9GL/ΔMGF, based on the deletion of all genes deleted in ASFV-G-Δ9GL and ASFV-G-ΔMGF. ASFV-G-Δ9GL/ΔMGF is the first derivative of a highly virulent ASFV field strain subjected to a double round of recombination events seeking to sequentially delete specific genes. ASFV-G-Δ9GL/ΔMGF showed a decreased ability to replicate in primary swine macrophage cultures relative to that of ASFV-G and ASFV-G-ΔMGF but similar to that of ASFV-G-Δ9GL. ASFV-G-Δ9GL/ΔMGF was attenuated when intramuscularly inoculated into swine, even at doses as high as 10(6) HAD50. Animals infected with doses ranging from 10(2) to 10(6) HAD50 did not present detectable levels of virus in blood at any time post-infection and they did not develop detectable levels of anti-ASFV antibodies. Importantly, ASFV-G-Δ9GL/ΔMGF does not induce protection against challenge with the virulent parental ASFV-G isolate. Results presented here suggest caution towards approaches involving genomic manipulations when developing rationally designed ASFV vaccine strains. PMID:27182007
Paul, Katharina T
Vaccination against the sexually transmitted Human Papilloma Virus (HPV), a necessary agent for the development of cervical cancer, has triggered much debate. In Austria, HPV policy turned from "lagging behind" in 2008 into "Europe's frontrunner" by 2013. Drawing on qualitative research, the article shows how the vaccine was transformed and made "good enough" over the course of five years. By means of tinkering and shifting storylines, policy officials and experts disassociated the vaccine from gender, vaccine manufacturers, and youth sexuality. Ultimately, the HPV vaccine functioned to strengthen the national immunization program. To this end, preventing an effective problematization of the extant screening program was essential.
Sereda A. D.
Full Text Available The review presents some data on structural and non-structural, regulatory proteins and enzymes of African swine fever (ASF virus. The variety of the virus biological characteristics is substantially caused by proteins belonging to multigenic families. It is suggested, that the protection development at ASF is provided not only by the membrane proteins, but also by the regulatory ones
Marine, Combe; Thierry, Bouvier; Olivier, Pringault; Emma, Rochelle-Newall; Corinne, Bouvier; Martin, Agis; The Thu, Pham; Jean-Pascal, Torreton; Van Thuoc, Chu; Bettarel, Yvan
Little information exists on the ecological adaptive responses of riverine microorganisms to the salinity changes that typically occur in transitional waters. This study examined the precise effects of a gradual increase in salinity (+3 units per day for 12 days) on freshwater virus and prokaryote communities collected in the Red River Delta (northern Vietnam). The abundance, activity, morphology and diversity of both communities were examined along this simulated salinity gradient (0-36). Three main successive ecological stages were observed: (1) a continuous decline in prokaryotic and viral abundance from the start of the salinization process up to salinity 12-15 together with a strong decrease in the proportion of active cells, (2) a shift in both community compositions (salinity 9-15) and (3) a marked prevalence of lysogenic over lytic cycles up to salinity 21 followed by a collapse of both types of viral infection. Finally, after salinity 21, and up to seawater salinities (i.e. 36) the prokaryotic community showed multiple signs of recovery with their abundance and function even reaching initial levels. These results suggest that most of the physiological and phylogenetic changes that occurred within the salinity range 10-20 seemed to favor the installation of osmotically adapted prokaryotes accompanied by a specific cortege of viral parasites which might both be able to survive and even proliferate in saltwater conditions.
Mary Ann S. Van Duyn, PhD, MPH, RD
Full Text Available IntroductionUsing a social marketing approach, we studied how best to adapt proven, evidence-based strategies to increase physical activity for use with underserved racial or ethnic groups.MethodsWe conducted focus groups with low-income Hispanic women in Texas, Hmong parents and their children in California, low-income African American women and men in the Mississippi Delta, and Native Hawaiian college students in Hawaii. We also interviewed key leaders of these communities. Topics of discussion were participants’ perceptions about 1 the benefits of engaging in physical activity, 2 the proposed evidence-based strategies for increasing each community’s level of physical activity, and 3 the benefits and barriers to following the proposed interventions for increasing physical activity. A total of 292 individuals participated in the study.ResultsAll groups considered that being physically active was part of their culture, and participants found culturally relevant suggestions for physical activities appealing. Overwhelmingly, strategies that aimed to create or improve social support and increase access to physical activity venues received the most positive feedback from all groups. Barriers to physical activity were not culturally specific; they are common to all underserved people (lack of time, transportation, access, neighborhood safety, or economic resources.ConclusionResults indicate that evidence-based strategies to increase physical activity need to be adapted for cultural relevance for each racial or ethnic group. Our research shows that members of four underserved populations are likely to respond to strategies that increase social support for physical activity and improve access to venues where they can be physically active. Further research is needed to test how to implement such strategies in ways that are embraced by community members.
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.
Villabona-Arenas, Christian Julian; Mondini, Adriano; Bosch, Irene; Schimdt, Diane J; Schimitt, Diane; Calzavara-Silva, Carlos E; Zanotto, Paolo M de A; Nogueira, Maurício L
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. PMID:23667626
Braae, U C; Johansen, M V; Ngowi, H A; Rasmussen, T B; Nielsen, J; Uttenthal, Å
The aim of the study was to assess whether blood samples collected onto FTA(®) cards could be used in combination with real-time PCR for the detection of African swine fever virus (ASFV) DNA in samples from resource-poor settings under the assumption that asymptomatically (sub-clinically) infected pigs may be present. Blood samples were collected from clinically healthy pigs from Mbeya Region, Tanzania. The blood samples were stored on FTA(®) cards and analysed by real-time PCR assays in duplicate; three pigs had high levels of viral DNA (Ct values of 27-29), and three pigs had a low level of viral DNA (Ct 36-45). Four pigs were positive in one of the duplicate samples only, but clear products of the expected size were obtained when the reactions were analysed by gel electrophoresis. For comparison, blood samples from pigs experimentally infected with either a pathogenic (OURT T88/1) or a non-pathogenic (OURT T88/3) isolate of ASFV were collected, stored on FTA(®) cards and analysed in the same way. The blood from pigs infected with the OURT T88/1 isolate showed high levels of viral DNA (Ct 22-33), whereas infection with non-pathogenic OURT T88/3 isolate resulted in only low levels of viral DNA (Ct 39) in samples collected at 10-14 days after inoculation.
Pathogenesis of highly virulent African swine fever virus in domestic pigs exposed via intraoropharyngeal, intranasopharyngeal, and intramuscular inoculation, and by direct contact with infected pigs.
Howey, Erin B; O'Donnell, Vivian; de Carvalho Ferreira, Helena C; Borca, Manuel V; Arzt, Jonathan
To investigate the pathogenesis of African swine fever virus (ASFV), domestic pigs (n=18) were challenged with a range (10(2)-10(6) 50% hemadsorbing doses (HAD50)) of the highly virulent ASFV-Malawi strain by inoculation via the intraoropharyngeal (IOP), intranasopharyngeal (INP), or intramuscular (IM) routes. A subsequent contact challenge experiment was performed in which six IOP-inoculated donor pigs were allowed to have direct contact (DC) with six naïve pigs for exposure times that varied from 24 to 72 h. All challenge routes resulted in clinical progression and postmortem lesions similar to those previously described in experimental and natural infection. The onset of clinical signs occurred between 1 and 7 days post inoculation (dpi) and included pyrexia with variable progression to obtundation, hematochezia, melena, moribundity and death with a duration of 4-11 days. Viremia was first detected between 4 and 5 dpi in all inoculation groups whereas ASFV shedding from the nasal cavity and tonsil was first detected at 3-9 dpi. IM and DC were the most consistent modes of infection, with 12/12 (100%) of pigs challenged by these routes becoming infected. Several clinical and virological parameters were significantly different between IM and DC groups indicating dissimilarity between these modes of infection. Amongst the simulated natural routes, INP inoculation resulted in the most consistent progression of disease across the widest range of doses whilst preserving simulation of natural exposure and therefore may provide a superior system for pathogenesis and vaccine efficacy investigation.
Full Text Available Abstract The present study characterized the homologous and heterologous immune response in type-I porcine reproductive and respiratory syndrome virus (PRRSV infection. Two experiments were conducted: in experiment 1, eight pigs were inoculated with PRRSV strain 3262 and 84 days post-inoculation (dpi they were challenged with either strain 3262 or strain 3267 and followed for the next 14 days (98 dpi. In experiment 2, eight pigs were inoculated with strain 3267 and challenged at 84 dpi as above. Clinical course, viremia, humoral response (neutralizing and non-neutralizing antibodies, NA and virus-specific IFN-γ responses (ELISPOT were evaluated all throughout the study. Serum levels of IL-1, IL-6, IL-8, TNF-α and TGF-β were determined (ELISA after the second challenge. In experiment 1 primo-inoculation with strain 3262 induced viremia of ≤ 28 days, low titres of homologous NA but strong IFN-γ responses. In contrast, strain 3267 induced longer viremias (up to 56 days, higher NA titres (≤ 6 log2 and lower IFN-γ responses. Inoculation with 3267 produced higher serum IL-8 levels. After the re-challenge at 84 dpi, pigs in experiment 1 developed mostly a one week viremia regardless of the strain used. In experiment 2, neither the homologous nor the heterologous challenge resulted in detectable viremia although PRRSV was present in tonsils of some animals. Homologous re-inoculation with 3267 produced elevated TGF-β levels in serum for 7–14 days but this did not occur with the heterologous re-inoculation. In conclusion, inoculation with different PRRSV strains result in different virological and immunological outcomes and in different degrees of homologous and heterologous protection.
Maree, Francois F; Blignaut, Belinda; de Beer, Tjaart A P; Visser, Nico; Rieder, Elizabeth A
Foot-and-mouth disease virus (FMDV) infects host cells by adhering to the alpha(V) subgroup of the integrin family of cellular receptors in a Arg-Gly-Asp (RGD) dependent manner. FMD viruses, propagated in non-host cell cultures are reported to acquire the ability to enter cells via alternative cell surface molecules. Sequencing analysis of SAT1 and SAT2 cell culture-adapted variants showed acquisition of positively charged amino acid residues within surface-exposed loops of the outer capsid structural proteins. The fixation of positively charged residues at position 110-112 in the beta F-beta G loop of VP1 of SAT1 isolates is thought to correlate with the acquisition of the ability to utilise alternative glycosaminoglycan (GAG) molecules for cell entry. Similarly, two SAT2 viruses that adapted readily to BHK-21 cells accumulated positively charged residues at positions 83 and 85 of the beta D-beta E loop of VP1. Both regions surround the fivefold axis of the virion. Recombinant viruses containing positively charged residues at position 110 and 112 of VP1 were able to infect CHO-K1 cells (that expresses GAG) and demonstrated increased infectivity in BHK-21 cells. Therefore, recombinant SAT viruses engineered to express substitutions that induce GAG-binding could be exploited in the rational design of vaccine seed stocks with improved growth properties in cell cultures. PMID:20637812
Ning-Zhu Hu; Yun-Zhang Hu; Hai-Jing Shi; Guo-Dong Liu; Su Qu
AIM: To investigate the molecular mechanism of celladaptation and rapid replication of hepatitis A virus strainH2 in KBM17 cells,METHODS: Virus of strain H2 at passage 7 was consecutivelypassaged in KBM17 cells for 22 passages, every passagewas incubated for 14 days. Antigenic and infectious titers ofevery passage and one-step growth dynamics of passage22 were determined with ELISA. Genomes of passage 6,passage 12, passage 18 and passage 22 were sequencedand compared with H2K7.RESULTS: During continuous passage of vaccine strain H2at passage K7 in KMB17 cells, infectious and antigenic titersincreased with the increase of passages, infectious titers atday 14 reached 6.77LgCCID50ml-1 for passage 6 (P6), 7.0LgCCID50ml-1 for passage 12 (P12), 7.33 LgCCID50ml-1 forpassage 18 (P18) and 7.83 LgCCID50ml-1 for passage 22(P22), respectively. The one-step growth dynamics showedthat replicating peak of P22 appeared at day 14 withinfectious titers of 7.83 LgCCID50ml-1 and antigenic titer of1:1024. After passage 22 a new cell-adapted variant (P22)of H2K7 with rapid and shortened replication cycle from 28days to 14 days was obtained. Sequencing and comparisonsof genomes of P6, P12, P18 and P22 showed that mutationalnumbers in genomes of different passages increased withadaptive passages, and mutations scattered over thegenome. In comparison with that of K7, P6 had only 6nucleotides (nt) mutations, P12 had 7 mutational changes,in addition to 6 same mutations with P6, there appeared anew mutation in 5′NTR at nucleotide position 591 resultingin a nucleotide exchange from A to G. P18 had 10 ntmutations, among the 10 mutations, 7 mutational changeswere same as with P12, three new mutational changesappeared in the genome, one in 5′NTR, one in 3C codingregion, one in 3D coding region, at P22 there appeared 18nucleotide changes in the genome, on the basis of P18,there occured additional 8 nucleotide mutations, two in5′NTR, three in 2C, one in 3A, one in 3C and one in 3D. Theresults
Neill, John D; Dubovi, Edward J; Ridpath, Julia F
Bovine viral diarrhea viruses (BVDV) are most commonly associated with infections of cattle. However, BVDV are often isolated from closely related ruminants with a number of BVDV-1b viruses being isolated from alpacas that were both acutely and persistently infected. The complete nucleotide sequence of the open reading frame of eleven alpaca-adapted BVDV isolates and the region encoding the envelope glycoproteins of an additional three isolates were determined. With the exception of one, all alpaca isolates were >99.2% similar at the nucleotide level. The Hercules isolate was more divergent, with 95.7% sequence identity to the other viruses. Sequence similarity of the 14 viruses indicated they were isolates of a single BVDV strain that had adapted to and were circulating through alpaca herds. Hercules was a more distantly related strain that has been isolated only once in Canada and represented a separate adaptation event that possessed the same adaptive changes. Comparison of amino acid sequences of alpaca and bovine-derived BVDV strains revealed three regions with amino acid sequences unique to all alpaca isolates. The first contained two small in-frame deletions near the N-terminus of the E2 glycoprotein. The second was found near the C-terminus of the E2 protein where four altered amino acids were located within a 30 amino acid domain that participates in E2 homodimerization. The third region contained three variable amino acids in the C-terminus of the E(rns) within the amphipathic helix membrane anchor. These changes were found in the polar side of the amphipathic helix and resulted in an increased charge within the polar face. Titration of bovine and alpaca viruses in both bovine and alpaca cells indicated that with increased charge in the amphipathic helix, the ability to infect alpaca cells also increased.
Rivers-Moore, N A; Jewitt, G P W
Water temperatures, and in particular daily maximum water temperatures, are a critical water quality parameter. An understanding of associated resource management issues, including links between water temperature variability and aquatic diversity values, should be part of any management programme that considers river systems. Simple rule-based models have been shown to be appropriate tools within an adaptive management approach, both because of their heuristic value and in their application for scenario generation. Such a model was developed to simulate changes in the condition factor of Chiloglanis anoterus [Crass, R.S., 1960. Notes on the freshwater fishes of Natal with descriptions of 4 new species. Annals of the Natal Museum 14, 405-458] (Pisces: Mochokidae) in response to annual frequency of exceedance of a threshold temperature under three broad environmental scenarios for part of the Sabie River falling within South Africa's Kruger National Park. This model has potential for application within the adaptive management programme being implemented by the Kruger National Park. Results show that under broad scenarios of a 10% reduction in mean daily flow rates, or a 2 degrees C increase in mean daily air temperatures, system variability is likely to increase relative to reference conditions . It is suggested that so-called "thresholds of probable concern" (TPCs), which are based on current levels of "natural" system variability, are useful as management targets for achieving a "desired future state" for the river system. The model, recognised as a preliminary hypothesis, highlights a lack of knowledge regarding the nature of system variability, and the correspondingly wide confidence limits of the proposed TPC restricts its utility in a short-term management context. Thus, it is now recognised that its value lies more in its use as a long-term modelling tool to reflect water temperature responses to flow variability. This highlights the fact that research
van Wilgen, Brian W; Govender, Navashni; Smit, Izak P J; MacFadyen, Sandra
This paper describes recent changes to the fire management policy of the 1.9 million ha Kruger National Park in South Africa. It provides a real-life example of adaptive learning in an environment where understanding is incomplete, but where management nonetheless has to proceed. The previous policy called for the application of fire to meet burnt area targets that were set for administrative subdivisions, and that were assessed at the scale of the entire park. This was problematic because the park is large and heterogeneous, and because sound ecological motivations that could link burning prescriptions to ecological objectives were missing. The new policy divides the park into five fire management zones on the basis of differences in mean annual rainfall, historic fire return periods, and geology. In addition, it proposes fire management actions designed to achieve specified ecological objectives in each zone, and includes fire-regime related thresholds and associated ecological outcomes against which to assess the effectiveness of management. The new policy is an improvement over previous iterations, but several challenges remain. Most important among these would be to continually improve the understanding of the effects of fire, and to develop frameworks for assessing the impacts of fire together with other ecosystem drivers that interact strongly with fire to influence the attainment of ecological objectives.
Full Text Available Compared to other avian leukosis viruses (ALV, ALV-J primarily induces myeloid leukemia and hemangioma and causes significant economic loss for the poultry industry. The ALV-J Env protein is hypothesized to be related to its unique pathogenesis. However, the molecular determinants of Env for ALV-J pathogenesis are unclear. In this study, we compared and analyzed GP37 of ALV-J Env and the EAV-HP sequence, which has high homology to that of ALV-J Env. Phylogenetic analysis revealed five groups of ALV-J GP37 and two novel ALV-J Envs with endemic GP85 and EAV-HP-like GP37. Furthermore, at least 15 virus-adapted mutations were detected in GP37 compared to the EAV-HP sequence. Further analysis demonstrated that three tyrosine-based motifs (YxxM, ITIM (immune tyrosine-based inhibitory motif and ITAM-like (immune tyrosine-based active motif like associated with immune disease and oncogenesis were found in the cytoplasmic tail of GP37. Based on the potential function and distribution of these motifs in GP37, ALV-J Env was grouped into three species, inhibitory Env, bifunctional Env and active Env. Accordingly, 36.91%, 61.74% and 1.34% of ALV-J Env sequences from GenBank are classified as inhibitory, bifunctional and active Env, respectively. Additionally, the Env of the ALV-J prototype strain, HPRS-103, and 17 of 18 EAV-HP sequences belong to the inhibitory Env. And models for signal transduction of the three ALV-J Env species were predicted. Our findings and models provide novel insights for identifying the roles and molecular mechanism of ALV-J Env in the unique pathogenesis of ALV-J.
Barigye, R; Melville, L F; Davis, S; Walsh, S; Hunt, N; Hunt, R
While virus neutralizing antibodies are known to be variably protective against bovine ephemeral fever (BEF) virus (BEFV) infections, the cytokine events that mediate the nascent adaptive immune response have not been defined in cattle. This study determined the plasma kinetics of IL-2, IFN-γ, IL-6, and IL-10 during the period of innate-immune response transition and evaluated the relationship between the virus neutralizing antibody response and viraemia in BEFV-infected cattle. Plasma from four virus-infected and uninfected negative control animals was tested by cytokine-specific immunoenzymatic assays, viraemia monitored by qRT-PCR, and virus neutralizing antibody titres determined using a standard protocol. Unlike the negative controls, plasma IL-6 and IL-10 were increased in all the virus-infected animals starting several days prior to initiation of viraemia. In one animal, plasma IL-2 and IFN-γ were consistently higher than in the other three virus-infected animals and the negative control mean. The animal with the strongest IL-2 and IFN-γ responses had the shortest viraemia while the heifer with the lowest IL-2/IFN-γ indices demonstrated the longest viraemia. Evidently, increase in plasma IL-6 and IL-10 precedes seroconversion during BEFV infections in cattle suggesting the two cytokines may influence immunological events that pave way to B-cell activation and seroconversion. While there is remarkable variability in IL-2 and IFN-γ expression amongst BEFV-infected animals, increased plasma levels of the two cytokines appear to be associated with a shorter viraemia. Ongoing studies will help define the precise role of T cells in anti-BEFV adaptive immune responses. PMID:27016765
Full Text Available Sutherlandia frutescens (L. R. Br. is widely used as an over the counter complementary medicine and in traditional medications by HIV seropositive adults living in South Africa; however the plant's safety has not been objectively studied. An adaptive two-stage randomized double-blind placebo controlled study was used to evaluate the safety of consuming dried S. frutescens by HIV seropositive adults with CD4 T-lymphocyte count of >350 cells/μL.In Stage 1 56 participants were randomized to S. frutescens 400, 800 or 1,200 mg twice daily or matching placebo for 24 weeks. In Stage 2 77 additional participants were randomized to either 1,200 mg S. frutescens or placebo. In the final analysis data from Stage 1 and Stage 2 were combined such that 107 participants were analysed (54 in the S. frutescens 1,200 mg arm and 53 in the placebo arm.S. frutescens did not change HIV viral load, and CD4 T-lymphocyte count was similar in the two arms at 24 weeks; however, mean and total burden of infection (BOI; defined as days of infection-related events in each participant was greater in the S. frutescens arm: mean (SD 5.0 (5.5 vs. 9.0 (12.7 days (p = 0.045, attributed to two tuberculosis cases in subjects taking isoniazid preventive therapy (IPT.A possible interaction between S. frutescens and IPT needs further evaluation, and may presage antagonistic interactions with other herbs having similar biochemical (antioxidant properties. No other safety issues relating to consumption of S. frutescens in this cohort were identified.ClinicalTrials.gov NCT00549523.
The literature relating to the social context of sexual relations in East and Central Africa has several implications for the heterosexual transmission of human immunodeficiency virus (HIV). Colonially created cities in the region still discriminate economically and socially against women. Rapid urbanization is occurring, but migrants maintain strong ties with rural areas. Traditional attitudes towards marriage and sexuality affect urban behavior in the extent of marital stability, the frequency of polygyny, and the emotional bond between spouses. Ethnic groups in Kampala and Nairobi exemplify the cultural foundations of two forms of sexual relations found in the region, one characterized by prostitution and the other by small circles of interchanging lovers. The first results in a more rapid spread of HIV through the urban population and outwards into rural areas. Each pattern exerts unique constraints on behavioral change and requires different prevention campaigns. PMID:2682946
The suitability of using two different enzyme-linked immunosorbent assays (ELISAs) for the detection of immunoglobulin G antibodies against the camel pox virus has been tested by examining 297 sera of dromedaries from Kenya, Somalia and Sudan. The ELISAs were based on an indirect method of antibody detection. One technique used direct conjugation of enzymes to antispecies-antibodies (C-EL), the other a biotin-avidin amplification system (BA-EL). Using the conventional technique (C-EL) on 196 sera of dromedaries from different ranches in Kenya during the period 1981 to 1984 we determined a high prevalence of antibodies, with titres of up to 1:4096. A comparison made for the years 1981 to 1984 showed a slight decrease in antibody titres. Five animals suffering from acute camel pox showed titres between 1:8192 and 1:32768; eight serum samples from Somalia, collected during an outbreak of camel pox, showed titres of 1:2048 to 1:8192. A high prevalence of antibodies was also found in 93 samples from Sudan; 95% of the animals showed titres of between 1:128 and 1:4096. Differences due to sex or age could not be determined. According to these results, camel pox appears to be endemic in the areas investigated. To test the applicability of the new BA-EL method, 60 camel sera were investigated. It was found that the sensitivity and specificity of this technique seem to be superior to those of the standard ELISA. The advantage of BA-EL is that it avoids direct conjugation of enzymes to antispecies-globulins which, in the case of exotic animals, are not commercially available. Both ELISAs can be regarded as suitable for serological screening tests and for rapid serological differentiation of orthopox and parapox virus infections, also in camels. (author)
Full Text Available Endogenous retroviruses (ERVs are remnants of ancient retroviral infections of the host germline transmitted vertically from generation to generation. It is hypothesized that some ERVs are used by the host as restriction factors to block the infection of pathogenic retroviruses. Indeed, some ERVs efficiently interfere with the replication of related exogenous retroviruses. However, data suggesting that these mechanisms have influenced the coevolution of endogenous and/or exogenous retroviruses and their hosts have been more difficult to obtain. Sheep are an interesting model system to study retrovirus-host coevolution because of the coexistence in this animal species of two exogenous (i.e., horizontally transmitted oncogenic retroviruses, Jaagsiekte sheep retrovirus and Enzootic nasal tumor virus, with highly related and biologically active endogenous retroviruses (enJSRVs. Here, we isolated and characterized the evolutionary history and molecular virology of 27 enJSRV proviruses. enJSRVs have been integrating in the host genome for the last 5-7 million y. Two enJSRV proviruses (enJS56A1 and enJSRV-20, which entered the host genome within the last 3 million y (before and during speciation within the genus Ovis, acquired in two temporally distinct events a defective Gag polyprotein resulting in a transdominant phenotype able to block late replication steps of related exogenous retroviruses. Both transdominant proviruses became fixed in the host genome before or around sheep domestication (approximately 9,000 y ago. Interestingly, a provirus escaping the transdominant enJSRVs has emerged very recently, most likely within the last 200 y. Thus, we determined sequentially distinct events during evolution that are indicative of an evolutionary antagonism between endogenous and exogenous retroviruses. This study strongly suggests that endogenization and selection of ERVs acting as restriction factors is a mechanism used by the host to fight retroviral
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.
Samrath, Devprabha; Shakya, Sanjay; Rawat, Nidhi; Gilhare, Varsha Rani; Singh, Fateh
Aim: Objective of the present study was to isolate bovine herpes virus Type 1 (BHV-1) from semen of infected bull and to adapt it onto embryonated eggs and Madin–Darby bovine kidney (MDBK) cell line. Further, the virus was identified by agar gel immunodiffusion (AGID) test. Materials and Methods: Semen samples were collected from five BHV-1 positive bulls previously confirmed for the presence of antibodies against BHV-1 using avidin-biotin enzyme linked immunosorbent assay test. The virus from semen samples was adapted in chorioallantoic membrane (CAM) of 11-day-old embryonated chickens eggs and in MDBK cell line. The presence of BHV-1 in infected CAM and cell culture fluid was confirmed by AGID test. Results: Virus infected CAM showed edema, congestion and thickening at first passage level. Small foci ranged from 1 to 2 mm in diameter, scattered all over the membrane were observed at first passage. More severe changes were observed in CAM after serial passaging. The large pock lesions, round in shape with opaque raised edge and depressed gray central area of necrosis ranged from 3 to 5 mm in diameter were developed at fourth passage. Blind passages in MDBK cell culture were made. The MDBK cell line at second passage level showed characteristic cytopathic effect viz. rounding of cells with shrinkage, followed by aggregation or clumping of cells which progressed rapidly and appeared as “bunch of grapes” at 72 h post inoculation. Few cells become elongated when compared with uninfected controls. A homogenate of CAM with distinct pock lesions and infected cell culture fluid developed precipitation line within 48 h against specific anti-BHV-1 immune serum by AGID test. Conclusion: BHV-1 was easily adapted in CAM of chicken embryos and in MDBK cell line. Virus infected CAM and cell culture fluid showed precipitin band by AGID test. PMID:27051213
Full Text Available Aim: Objective of the present study was to isolate bovine herpes virus Type 1 (BHV-1 from semen of infected bull and to adapt it onto embryonated eggs and Madin–Darby bovine kidney (MDBK cell line. Further, the virus was identified by agar gel immunodiffusion (AGID test. Materials and Methods: Semen samples were collected from five BHV-1 positive bulls previously confirmed for the presence of antibodies against BHV-1 using avidin-biotin enzyme linked immunosorbent assay test. The virus from semen samples was adapted in chorioallantoic membrane (CAM of 11-day-old embryonated chickens eggs and in MDBK cell line. The presence of BHV-1 in infected CAM and cell culture fluid was confirmed by AGID test. Results: Virus infected CAM showed edema, congestion and thickening at first passage level. Small foci ranged from 1 to 2 mm in diameter, scattered all over the membrane were observed at first passage. More severe changes were observed in CAM after serial passaging. The large pock lesions, round in shape with opaque raised edge and depressed gray central area of necrosis ranged from 3 to 5 mm in diameter were developed at fourth passage. Blind passages in MDBK cell culture were made. The MDBK cell line at second passage level showed characteristic cytopathic effect viz. rounding of cells with shrinkage, followed by aggregation or clumping of cells which progressed rapidly and appeared as “bunch of grapes” at 72 h post inoculation. Few cells become elongated when compared with uninfected controls. A homogenate of CAM with distinct pock lesions and infected cell culture fluid developed precipitation line within 48 h against specific anti-BHV-1 immune serum by AGID test. Conclusion: BHV-1 was easily adapted in CAM of chicken embryos and in MDBK cell line. Virus infected CAM and cell culture fluid showed precipitin band by AGID test.
Doniņa, Simona; Strēle, Ieva; Proboka, Guna; Auziņš, Jurgis; Alberts, Pēteris; Jonsson, Björn; Venskus, Dite; Muceniece, Aina
An oncolytic, nonpathogenic ECHO-7 virus adapted for melanoma that has not been genetically modified (Rigvir) is approved and registered for virotherapy, an active and specific immunotherapy, in Latvia since 2004. The present retrospective study was carried out to determine the effectiveness of Rigvir in substage IB, IIA, IIB and IIC melanoma patients on time to progression and overall survival. White patients (N=79) who had undergone surgical excision of the primary melanoma tumour were incl...
Fishbourne, Emma; Hutet, Evelyne; Abrams, Charles; Cariolet, Roland; Le Potier, Marie-Frédérique; Takamatsu, Haru-H; Dixon, Linda K
Modulation of the expression of chemokines and chemokine receptors in whole blood was compared following infection of pigs with high and low virulence isolates of African swine fever virus. Levels of mRNAs for CCL2, CCL3L1, CCL4, CXCL10, CCR1 and CCR5 were significantly increased in at least one time point following infection in two experiments and CCL5, CCR9 and CXCR4 mRNA were significantly increased in one of the experiments. The results showed that greatest fold increases in mRNAs for CXCL10 and CCL2 were observed following infection of pigs. CXCL10 mRNA was increased by up to 15 fold in infected compared to uninfected pigs. CXCL10 protein was also detected in serum from pigs infected with the high virulence Benin 97/1 isolate. Levels of CCL2 mRNA were increased in pigs infected with high virulence Benin 97/1 isolate compared to low virulence OURT88/3 isolate and this correlated with an increase of greater than 30 fold in levels of CCL2 protein detected in serum from pigs infected with this isolate. An increase in overall chemotaxis active compounds in defibrinated plasma samples from Benin 97/1 infected pigs was observed at 3 days post-infection (dpi) and a decrease by 7 dpi as measured by chemotaxis assay using normal pig leucocytes in vitro. Increased levels of CXCL10 may either contribute to the activation of lymphocyte priming toward the Th1 phenotype or induction of T lymphocyte apoptosis. Increased levels of CCL2, a chemoattractant for macrophages, may result in increased recruitment of monocytes from bone marrow thus increasing the pool of cells susceptible to infection.
Nambei, W S; Rawago-Mandjiza, D; Gbangbangai, E
The aim of this study was to determine the seroprevalence of HIV, the hepatitis B and C viruses, and syphilis as well the risk factors for these diseases among blood donors in Bangui, Central Africa Republic. This cross-sectional study examined samples from donors giving blood in August and September, 2013. HIV1/2 antibodies was screened with the Determine and Unigold HIV tests. Hepatitis B surface antigens were detected by sandwich immunochromatographic methods (DIAspot HBsAg test), and antibodies to HCV by the DIAspot test strip. Syphilis was diagnosed with the VDRL and TPHA methods (Omega Diagnostic, UK). The Chi(2) test was used for statistical analysis. The study included samples from 551 individuals, 350 (63.52%) of whom were frequent volunteer donors. In all, 132 (23.95%) were infected with at least one pathogen. The overall seroprevalence rate was 8.89% for HBV, 4.72% for HCV, 4.36% for syphilis, and 5.98% for HIV. Eight patients had two concomitant infections, with HIV-HBV the most common combination. Compared to long-term volunteers, first-time donors were more often infected by at least one of the pathogens we screened for, most especially HVB (OR = 5.06; 95% CI = 4.22-7.11) and syphilis (OR = 2.05; 95% CI = 2.02-7.44). Our findings indicate the high seroprevalence of transfusion-transmitted infections in blood donated in Bangui. The most common combined infections were HIV-HBV. The most common risk factor was a family history of HBV infection, and especially, mother-child transmission. PMID:27412978
Joel Fleury Djoba Siawaya
Full Text Available OBJECTIVE: The purpose of this study was to (1 describe the distribution of Chlamydia trachomatis (CT and Human Immunodeficiency Virus (HIV cases across gender and age groups in Libreville (Gabon; (2 examine Gabonese Sexually Transmitted Infections (STIs-related risk behaviour. METHODS: The sampled population was people attending the "Laboratoire National de Santé Plublique". Between 2007 and 2011, 14 667 and 9 542 people respectively, were tested for CT and HIV infections. 1 854 of them were tested for both infections. We calculated CT and HIV rates across gender and age groups. Also analysed was the groups' contribution to the general CT and HIV epidemiology. STIs-related risk behaviours were assessed in 224 men and 795 women (between July 2011 and March 2013 who agreed and answered a questionnaire including questions on their marital status, number of sex partners, sexual practices, history of STIs, sex frequency and condom use. RESULTS: Data showed a 24% dropped in the CT infection rate between 2007 and 2010, followed by a 14% increase in 2011. The HIV infection rates for the same period were between 15% and 16%. The risk of a CT-positive subject getting HIV is about 0.71 times the risk of a CT-negative subject. Young adult aged between 18 and 35 years old represented 65.2% of people who had STIs. 80% of women and 66% of men confessed to an inconsistent use of condoms. 11.6% of women and 48% of men declared having multiple sex partners. 61% of questioned women and 67% of men declared knowing their HIV status. CONCLUSIONS: In this Gabonese setting, the population-aged from 18 to 35 years is the most affected by STIs. Other matters of concern are the inconsistent use of protection and sex with non-spousal or non-life partners.
Full Text Available Genotype E of hepatitis B virus (HBV has not been described in Brazil and is found mainly in Africa. Genotype A is the most prevalent in Brazil, and genotypes B, C, D, and F have already been reported. We report here an HBV genotype E-infected patient and some characterization of surface (S protein, DNA polymerase (P and precore/core (preC/C coding regions based on the viral genome. The patient is a 31-year-old black man with chronic hepatitis B who was born and raised in Angola. He has been followed by a hepatologist in São Paulo, Brazil, since November 2003, and he is a frequent traveler to Latin America, Africa, and Europe. In 2003, he was diagnosed with HBV infection and started treatment with lamivudine with the later addition of adefovir dipivoxil. No known risk factor was identified. Serologically, he is HBsAg and anti-HBe positive, but HBeAg and anti-HBs negative. DNA sequence analysis of the S/P region confirmed that this patient is infected with genotype E, subtype ayw4. The preC/C region showed G1896A and G1899A mutations but no mutations in the basal core promoter. Nucleotide substitutions common in genotype E were also observed (C1772, T1858 and A1757. Although this is not an autochthonous case and there is no evidence of further spread, the description of this case in Brazil highlights the current risk of viral genotypes spreading with unprecedented speed due to constant travel around the world.
Nagashima, Shigeo; Kobayashi, Tominari; Tanaka, Toshinori; Tanggis; Jirintai, Suljid; Takahashi, Masaharu; Nishizawa, Tsutomu; Okamoto, Hiroaki
To characterize the genomic mutations of hepatitis E virus (HEV) during consecutive passages associated with adaptation to growth in cell culture, a cloned genotype 3 HEV [pJE03-1760F/wt, starting virus (SV)] was passaged 10 times in A549 cells, and the entire genomic sequence of the passage 10 (P10) progeny was determined. Compared to SV, P10 virus possessed two non-synonymous (T2808C and A5054G) and four synonymous mutations (C1213T, T2557C, C3118T and C4435T) in the ORF1. Full-length infectious cDNA clones with a single, double (T2808C and A5054G), or all six mutations, identical to P10, were constructed, and their replication capacity was compared. Four (C1213T, T2557C, T2808C and A5054G) of the six viruses with a single mutation grew more efficiently than SV. The P10 virus propagated more rapidly and grew more efficiently than SV and T2808C+A5054G and reached a higher viral load (95.1- and 8.5-fold, respectively) at 20days post-inoculation. An immunofluorescence analysis revealed that a high percentage (>80%) of cells inoculated with the P10 virus expressed ORF2 proteins, while relatively low percentages (nearly 30% or 5%) inoculated with T2808C+A5054G or SV, respectively, expressed ORF2 proteins. We found that not only non-synonymous but also synonymous HEV mutations are independently associated with increased virus production. PMID:27485920
Peter Kojo Boateng
In the semi-arid tropics of West Africa where farming is the major livelihood source, it is claimed that African farmers are degrading their land: first because of shifting cultivation, later because population growth brought about “over-cultivation” or farm expansion and the scattering of more farms on the landscape. In response to these issues, West African governments have emphasised the need and rolled out programmes for modernisation of smallholder agriculture through promotion of capit...
Along with thriving Sino-African economic and trade ties,Chinese companies have attached greater importance to their social responsibility to Africans.More than 2,000 sweaters woven by Chinese mothers were sent to orphans and disabled children in Kenya and four other African countries in September. This activity was launched by Hengyuanxiang,aleading Chinese wool manufacturer.
Along with thriving Sino-African economic and trade ties,Chinese companies have attached greater importance to their social responsibility to Africans.More than 2,000 sweaters woven by Chinese mothers were sent to orphans and disabled children in Kenya and four other African countries in September.This activity was launched by Hengyuanxiang,a leading Chinese wool manufacturer.
transmembrane domain (.alpha.), in the cytoplasmic part (.beta.) or at the NS2/NS3 cleavage site (y). Following transfection of Huh7.5 cells with RNA transcripts, infectious viruses were produced in the ED43/JFH1-.beta. and -y cultures only. Compared to the 2a control virus, production of infectious viruses...... was significantly delayed. However, in subsequent passages efficient spread of infection and high HCV RNA titers were obtained. Infectivity titers were approximately 10-fold lower than for the 2a control virus. Sequence analysis of recovered 4a/2a recombinants from 3 serial passages and subsequent reverse genetic...
Yang, Heng; Lv, Minna; Sun, Minfei; Lin, Liqin; Kou, Meilin; Gao, Lin; Liao, Defang; Xiong, Heli; He, Yuwen; Li, Huachun
Bluetongue virus (BTV) mainly infects sheep but can be transmitted to other domestic and wild ruminants, resulting in a considerable financial burden and trade restriction. Our understanding of the origin, movement, and distribution of BTV has been hindered by the fact that this virus has a segmented genome with the possibility of reassortment, the existence of 27 identified serotypes, and a lack of complete sequences of viruses isolated from different parts of the world. BTV serotype 7 is one of the prevalent BTV serotypes in Asia. Nonetheless, no complete genomic sequence of an Asian isolate of this serotype is available. In an effort to understand the molecular epidemiology of BTV infection in China, for the first time, we report here the complete genome sequence of a BTV serotype 7 strain, GDST008, which was isolated in 2014 in China. This sequence also represents the first complete genome sequence of a BTV serotype 7 from Asia and the third one in the world. Sequence analysis suggests that GDST008 consists of segments from BTV viruses of African lineage as well as those from China. Together, these results improve our understanding of the origin, emergence/re-emergence, and movement of BTV and thus can be applied in the development of vaccines and diagnostics. PMID:26497176
Mahieux, R; Ibrahim, F; Mauclere, P; Herve, V; Michel, P; Tekaia, F; Chappey, C; Garin, B; Van Der Ryst, E; Guillemain, B; Ledru, E; Delaporte, E; de The, G; Gessain, A
To gain new insights on the origin, evolution, and modes of dissemination of human T-cell leukemia virus type I (HTLV-1), we performed a molecular analysis of 58 new African HTLV-1 strains (18 from West Africa, 36 from Central Africa, and 4 from South Africa) originating from 13 countries. Of particular interest were eight strains from Pygmies of remote areas of Cameroon and the Central African Republic (CAR), considered to be the oldest inhabitants of these regions. Eight long-term activated T-cell lines producing HTLV-1 gag and env antigens were established from peripheral blood mononuclear cell cultures of HTLV-1 seropositive individuals, including three from Pygmies. A fragment of the env gene encompassing most of the gp21 transmembrane region was sequenced for the 58 new strains, while the complete long terminal repeat (LTR) region was sequenced for 9 strains, including 4 from Pygmies. Comparative sequence analyses and phylogenetic studies performed on both the env and LTR regions by the neighbor-joining and DNA parsimony methods demonstrated that all 22 strains from West and South Africa belong to the widespread cosmopolitan subtype (also called HTLV-1 subtype A). Within or alongside the previously described Zairian cluster (HTLV-1 subtype B), we discovered a number of new HTLV-1 variants forming different subgroups corresponding mainly to the geographical origins of the infected persons, Cameroon, Gabon, and Zaire. Six of the eight Pygmy strains clustered together within this Central African subtype, suggesting a common origin. Furthermore, three new strains (two originating from Pygmies from Cameroon and the CAR, respectively, and one from a Gabonese individual) were particularly divergent and formed a distinct new phylogenetic cluster, characterized by specific mutations and occupying in most analyses a unique phylogenetic position between the large Central African genotype (HTLV-1 subtype B) and the Melanesian subtype (HTLV-1 subtype C). We have
Vartanian, Jean-Pierre; Pineau, Pascal; Henry, Michel; Hamilton, William D.; Muller, Martin N.; Wrangham, Richard W.; Wain-Hobson, Simon
DNAs from four wild chimpanzees (Pan troglodytes schweinfurthi) from eastern Africa were screened for 14 DNA viruses and retroviruses. Between two and three viruses were found in each animal. An entire hepatitis B virus (HBV) genome was amplified and sequenced from samples taken from one animal. This indicates that HBV is distributed across the entire range of chimpanzee habitats.
Dwivedi, Varun; Manickam, Cordelia; Dhakal, Santosh; Binjawadagi, Basavaraj; Ouyang, Kang; Hiremath, Jagadish; Khatri, Mahesh; Hague, Jacquelyn Gervay; Lee, Chang Won; Renukaradhya, Gourapura J
Pigs are considered as the source of some of the emerging human flu viruses. Inactivated swine influenza virus (SwIV) vaccine has been in use in the US swine herds, but it failed to control the flu outbreaks. The main reason has been attributed to lack of induction of strong local mucosal immunity in the respiratory tract. Invariant natural killer T (iNKT) cell is a unique T cell subset, and activation of iNKT cell using its ligand α-Galactosylceramide (α-GalCer) has been shown to potentiate the cross-protective immunity to inactivated influenza virus vaccine candidates in mice. Recently, we discovered iNKT cell in pig and demonstrated its activation using α-GalCer. In this study, we evaluated the efficacy of an inactivated H1N1 SwIV coadministered with α-GalCer intranasally against a homologous viral challenge. Our results demonstrated the potent adjuvant effects of α-GalCer in potentiating both innate and adaptive immune responses to SwIV Ags in the lungs of pigs, which resulted in reduction in the lung viral load by 3 logs compared to without adjuvant. Immunologically, in the lungs of pigs vaccinated with α-GalCer an increased virus specific IgA response, IFN-α secretion and NK cell-cytotoxicity was observed. In addition, iNKT cell-stimulation enhanced the secretion of Th1 cytokines (IFN-γ and IL-12) and reduced the production of immunosuppressive cytokines (IL-10 and TGF-β) in the lungs of pigs⋅ In conclusion, we demonstrated for the first time iNKT cell adjuvant effects in pigs to SwIV Ags through augmenting the innate and adaptive immune responses in the respiratory tract.
Norris, Stephen P.; Macnab, John S.; Wonham, Marjorie; de Vries, Gerda
This paper promotes the use of adapted primary literature as a curriculum and instruction innovation for use in high school. Adapted primary literature is useful for promoting an understanding of scientific and mathematical reasoning and argument and for introducing modern science into the schools. We describe a prototype adapted from a published…
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
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.
Tan, Mei; Reich, Jodi; Hart, Lesley; Thuma, Philip E.; Grigorenko, Elena L.
Generally accepted as universal, the construct of adaptive behavior differs in its manifestations across different cultures and settings. The Vineland-II (Sparrow et al. in "Vineland Adaptive Behavior Scales, Second edn." AGS Publishing, Circle Pines, MN, 2005) was translated into Chitonga and adapted to the setting of rural Southern…
Naar-King, Sylvie; Ellis, Deborah; Kolmodin, Karen; Cunningham, Phillippe; Secord, Elizabeth
African-American adolescents have the highest rates of asthma morbidity and mortality, yet there are few successful behavioral interventions to improve illness management for this group. Mental health providers have an opportunity to expand their services and impact by targeting adolescents with poor asthma management. We describe the adaptation…
Ripa, M; Pogliaghi, M; Chiappetta, S; Galli, L; Pensieroso, S; Cavarelli, M; Scarlatti, G; De Biasi, S; Cossarizza, A; De Battista, D; Malnati, M; Lazzarin, A; Nozza, S; Tambussi, G
We evaluated the dynamics of innate and adaptive immunity in patients treated with combined antiretroviral therapy (cART) during primary human immunodeficiency virus infection (PHI), enrolled in a prospective randomized trial (MAIN, EUDRACT 2008-007004-29). After 48 weeks of cART, we documented a reduction in activated B cells and CD8(+) T cells. Natural killer cell and dendritic cell frequencies were measured and a decrease in CD16(+) CD56(dim) with a reciprocal rise in CD56(high) natural killer cells and an increase in myeloid and plasmacytoid dendritic cells were recorded. In conclusion, 48 weeks of cART during PHI showed significant benefits for both innate and adaptive immunity.
Senthilkumar, T M A; Priyadharsini, C V; Raja, P; Kumanan, K
Infectious bursal disease virus is an avian pathogen that causes huge morbidity and mortality in the poultry sector all over the world. Here, we report the full-length genome sequence of an Indian strain, MB11/ABT/MVC/2016, isolated from a commercial broiler flock. This is a first report of a complete genome sequence of infectious bursal disease virus from India. PMID:27174268
Kerr, Peter J.; Rogers, Matthew B.; Fitch, Adam; DePasse, Jay V.; Cattadori, Isabella M.; Hudson, Peter J.; Tscharke, David C.; Holmes, Edward C.; Ghedin, Elodie
Myxomatosis is a rapidly lethal disease of European rabbits that is caused by myxoma virus (MYXV). The introduction of a South American strain of MYXV into the European rabbit population of Australia is the classic case of host-pathogen coevolution following cross-species transmission. The most virulent strains of MYXV for European rabbits are the Californian viruses, found in the Pacific states of the United States and the Baja Peninsula, Mexico. The natural host of Californian MYXV is the b...
Alexander T. Ciota; Ehrbar, Dylan J.; MATACCHIERO, AMY C.; Van Slyke, Greta A; Kramer, Laura D.
Background Virulence is often coupled with replicative fitness of viruses in vertebrate systems, yet the relationship between virulence and fitness of arthropod-borne viruses (arboviruses) in invertebrates has not been evaluated. Although the interactions between vector-borne pathogens and their invertebrate hosts have been characterized as being largely benign, some costs of arbovirus exposure have been identified for mosquitoes. The extent to which these costs may be strain-specific and the...
Gong, Wenjie; Lu, Zongji; Zhang, Li; Xie, Xiaoming; Jiang, Daliang; Jia, Junjie; Guo, Huancheng; Shi, Jishu; Tu, Changchun
Classical swine fever (CSF) still causes substantial economic losses in the pig industry in China. This study reports the isolation and characterization of a field CSF virus named GD53/2011 from pig kidney tissue collected during a CSF outbreak in Guangdong province, China. Phylogenetic analysis based on the full-length E2 gene sequence revealed that this isolate belongs to CSFV sub-subgenotype 2.1c. To further understand the replication characteristics, GD53/2011 was subsequently adapted in PK-15 cells, and its full-length genome was sequenced. After adaptation in PK-15 cells, the titer of GD53/2011 was significantly increased from 10(3.39) TCID50/ml at passage 6 (F6) to 10(8.50) TCID50/ml at passage 46 (F46) with the peak titer obtained at 48 h post-inoculation. Sequence comparison revealed that the E(rns) gene at passages 6, 15, and 25 of GD53/2011 was identical to that in the original tissue, but one amino acid substitution (S476R) was detected at passages 35 and 46. Furthermore, E2 gene sequences at passages 6, 15, 25, 35, and 46 was found identical to that in the original tissue, indicating that the E2 gene was stable during CSF virus adaptation in PK-15 cells. Full-length protein sequence comparison of GD53/2011 with other 2.1 sub-subgenotype isolates showed that Core and NS5A, rather than E2, are more genetically variable. Taken together, a field CSFV strain GD53/2011 was isolated, fully sequenced, and adapted to high growth titer in PK-15 cells, which might be suitable for future studies on CSFV infection, replication, and vaccine development. PMID:27155669
Gardner, Christina L; Hritz, Jozef; Sun, Chengqun; Vanlandingham, Dana L; Song, Timothy Y; Ghedin, Elodie; Higgs, Stephen; Klimstra, William B; Ryman, Kate D
Mosquito-borne chikungunya virus (CHIKV) is a positive-sense, single-stranded RNA virus from the genus Alphavirus, family Togaviridae, which causes fever, rash and severe persistent polyarthralgia in humans. Since there are currently no FDA licensed vaccines or antiviral therapies for CHIKV, the development of vaccine candidates is of critical importance. Historically, live-attenuated vaccines (LAVs) for protection against arthropod-borne viruses have been created by blind cell culture passage leading to attenuation of disease, while maintaining immunogenicity. Attenuation may occur via multiple mechanisms. However, all examined arbovirus LAVs have in common the acquisition of positively charged amino acid substitutions in cell-surface attachment proteins that render virus infection partially dependent upon heparan sulfate (HS), a ubiquitously expressed sulfated polysaccharide, and appear to attenuate by retarding dissemination of virus particles in vivo. We previously reported that, like other wild-type Old World alphaviruses, CHIKV strain, La Réunion, (CHIKV-LR), does not depend upon HS for infectivity. To deliberately identify CHIKV attachment protein mutations that could be combined with other attenuating processes in a LAV candidate, we passaged CHIKV-LR on evolutionarily divergent cell-types. A panel of single amino acid substitutions was identified in the E2 glycoprotein of passaged virus populations that were predicted to increase electrostatic potential. Each of these substitutions was made in the CHIKV-LR cDNA clone and comparisons of the mutant viruses revealed surface exposure of the mutated residue on the spike and sensitivity to competition with the HS analog, heparin, to be primary correlates of attenuation in vivo. Furthermore, we have identified a mutation at E2 position 79 as a promising candidate for inclusion in a CHIKV LAV.
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)
Lim, Tae-Hyun; Youn, Ha-Na; Yuk, Seong-Su; Kwon, Jung-Hoon; Hong, Woo-Tack; Gwon, Gyeong-Bin; Lee, Jung-Ah; Lee, Joong-Bok; Lee, Sang-Won; Song, Chang-Seon
A natural recombinant nephropathogenic K40/09 strain of infectious bronchitis virus (IBV) was heat-adapted for possible future use as live attenuated vaccine. The K40/09 strain was selected during successive serial passages in specific-pathogen free (SPF) embryonated eggs at sub-optimal higher temperature (56°C). Unlike the parental strain, the attenuated strain, designated K40/09 HP50, was found to be safe in 1-day-old SPF chicks, which showed neither mortality nor signs of morbidity, and rarely induced ciliostasis or histological changes in the trachea and kidney after intraocular and fine-spray administration. K40/09 HP50 provided almost complete protection against two distinct subgroups of a nephropathogenic strain (KM91-like and QX-like subgroup) and elicited the production of high titers of neutralizing antibody (neutralization index of 3.6). We conclude that the K40/09 HP50 vaccine virus is rapidly attenuated by heat adaptation and exhibits the desired level of attenuation, immunogenicity, and protective efficacy required for a live attenuated vaccine. These results indicate that the K40/09 vaccine could be helpful for the reduction of economic losses caused by recently emergent nephropathogenic IBV infection in many countries.
López, Carolina B; Moltedo, Bruno; Alexopoulou, Lena; Bonifaz, Laura; Flavell, Richard A; Moran, Thomas M
TLR signaling leads to dendritic cell (DC) maturation and immunity to diverse pathogens. The stimulation of TLRs by conserved viral structures is the only described mechanism leading to DC maturation after a virus infection. In this report, we demonstrate that mouse myeloid DCs mature normally after in vivo and in vitro infection with Sendai virus (SeV) in the absence of TLR3, 7, 8, or 9 signaling. DC maturation by SeV requires virus replication not necessary for TLR-mediated triggering. Moreover, DCs deficient in TLR signaling efficiently prime for Th1 immunity after infection with influenza or SeV, generating IFN-gamma-producing T cells, CTLs and antiviral Abs. We have previously demonstrated that SeV induces DC maturation independently of the presence of type I IFN, which has been reported to mature DCs in a TLR-independent manner. The data presented here provide evidence for the existence of a novel intracellular pathway independent of TLR-mediated signaling responsible for live virus triggering of DC maturation and demonstrate its critical role in the onset of antiviral immunity. The revelation of this pathway should stimulate invigorating research into the mechanism for virus-induced DC maturation and immunity.
Comparison Re-invented: Adaptation of Universal Methods to African Studies (Conference Report Die Wiederentdeckung des Vergleichs: Zur Anwendung universeller Methoden in der Afrikaforschung (Konferenzbericht
Full Text Available Drawing from a combination of specific, empirical research projects with different theoretical backgrounds, a workshop discussed one methodological aspect often somewhat overlooked in African Studies: comparison. Participants addressed several questions, along with presenting overviews of how different disciplines within African Studies approach comparison in their research and naming specific challenges within individual research projects. The questions examined included: Why is explicit comparative research so rare in African Studies? Is comparative research more difficult in the African context than in other regions? Does it benefit our research? Should scholars strive to generalise beyond individual cases? Do studies in our field require an explicit comparative design, or will implicit comparison suffice? Cross-discipline communication should help us to move forward in this methodological debate, though in the end the subject matter and specific research question will lead to the appropriate comparative approach, not the other way round.Mit Blick auf einige empirische Forschungsprojekte mit jeweils unterschiedlichem theoretischem Hintergrund wurde im Rahmen eines Workshops ein methodologischer Aspekt debattiert, der in der Afrikaforschung wenig Beachtung erfährt: der Vergleich. Die Teilnehmer(innen entwickelten Fragestellungen, stellten jeweils dar, inwieweit in den verschiedene Disziplinen der Afrikaforschung der Vergleich als Methode eingesetzt wird, und benannten spezifische Herausforderungen in diesem Zusammenhang für einzelne Forschungsprojekte. Unter anderem wurden folgende Fragen erörtert: Warum ist die explizit vergleichende Methode in der Afrikaforschung so selten? Ist vergleichende Forschung im Kontext Afrikas schwieriger anwendbar als in der Forschung zu anderen Regionen? Verbessert sie unsere Forschungsresultate? Sollten sich Forscher um Generalisierungen jenseits der Einzelfallstudien bemühen? Ist in der Afrikaforschung eine
A recombinant live attenuated influenza virus (LAIV) deltaH5N1 vaccine with a modified hemagglutinin (HA) and intact neuraminidase genes from A/Vietnam/1203/04 (H5N1) and the six remaining genome segments from A/Ann Arbor/6/60 (H2N2) cold-adapted (AA ca) virus was attenuated in chickens, mice and fe...
Ayebazibwe, C.; Mwiine, F. N.; Balinda, S. N.;
the presence of antibodies against FMDV serotypes in wildlife in Uganda, serological studies were performed on buffalo serum samples collected between 2001 and 2003. Thirty-eight samples from African buffalos collected from Lake Mburo, Kidepo Valley, Murchison Falls and Queen Elizabeth National Parks were...... immunosorbent assay (ELISAs). High titres of antibodies (≥1 : 160) against FMDV serotypes SAT 1, SAT 2 and SAT 3 were identified. This study suggests that African buffalos in the different national parks in Uganda may play an important role in the epidemiology of SAT serotypes of FMDV....
Gottwein, J.M.; Scheel, Troels Kasper Høyer; Hoegh, A.M.;
(immunostaining), HCV RNA titers (real-time PCR), and infectivity titers (50% tissue culture infectious dose). The role of mutations identified by sequencing of recovered S52/JFH1 viruses was analyzed by reverse genetics studies. RESULTS: S52/JFH1 and J6/JFH viruses passaged in Huh7.5 cells showed comparable......BACKGROUND & AIMS: Recently, full viral life cycle hepatitis C virus (HCV) cell culture systems were developed for strain JFH1 (genotype 2a) and an intragenotypic 2a/2a genome (J6/JFH). We aimed at exploiting the unique JFH1 replication characteristics to develop culture systems for genotype 3a......, which has a high prevalence worldwide. METHODS: Huh7.5 cells were transfected with RNA transcripts of an intergenotypic 3a/JFH1 recombinant with core, E1, E2, p7, and NS2 of the 3a reference strain S52, and released viruses were passaged. Cultures were examined for HCV core and/or NS5A expression...
Gottwein, Judith; Scheel, Troels; Høgh, Mette;
BACKGROUND & AIMS: Recently, full viral life cycle hepatitis C virus (HCV) cell culture systems were developed for strain JFH1 (genotype 2a) and an intragenotypic 2a/2a genome (J6/JFH). We aimed at exploiting the unique JFH1 replication characteristics to develop culture systems for genotype 3a, ...
Full text: Infectious bursal disease virus (IBDV) causes a highly contagious immunosuppressive as well as fatal disease known as infectious bursal disease (IBD) or Gumboro disease in young chickens. IBDV is a dsRNA virus belonging to the family Birnaviridae having a bisegmented genome. Very virulent (vv) IBDV does not replicate in common tissue culture; adaptation to tissue culture following repeated passages in embryonated eggs results in too much attenuation. It has been reported that only a few amino acids in the VP2 are responsible for tissue culture adaptation. In the present study, full-length cDNA corresponding to the genome segments A and B of a Bangladeshi vvIBDV strain BD-3/99 were synthesised and amplified by reverse transcription - polymerase chain reaction (RT-PCR) in overlapping fragments. The PCR amplicons were used to construct full-length cDNA clones of both segments in plasmid vectors along with the T7 promoter tagged at the 5'-end. Complete nucleotide sequences of both genome segments of BD 3/99 were established (GenBank Accession No. AF352776 and AF36270) and compared with 16 and 17 published sequences of segment A and segment B of IBDV, respectively, using Clustal V method of multiple alignment analysis (MegAlign, Lasergene, DNASTAR Inc., USA). In phylogenetic analysis BD-3/99 clustered with other vvIBDV strains isolated earlier from Europe, Asia and Africa.The reverse genetics technique was optimised for BD-3/99. The plasmids were linearised with appropriate restriction enzymes and cRNA corresponding to both segment A and segment B of BD-3/99 were transcribed in vitro under the control of T7 promoter. Freshly prepared chicken embryo fibroblast (CEF) cell monolayer was then transfected with the transcribed cRNA. Transfection of CEF cells with this wild-type cRNA resulted in the formation of infectious virus particles but the progeny virus could not be passaged any further in fresh CEF cells. However, this molecularly cloned virus (BD-3mc) could
Faber, F E; van Kleef, M; Tshilwane, S I; Pretorius, A
It was shown in a previous study that proliferating CD8+ T cells could be detected in immune horse peripheral blood mononuclear cells (PBMC) when stimulated with African horse sickness virus serotype 4 (AHSV4). In this study the cytotoxicity of CD8+ T cells were tested by using the fluorescent antigen-transfected target cells-cytotoxic T lymphocytes (FATT-CTL) assay, for both the virus and its individual proteins expressed in Escherichia coli. This CTL assay measures the killing of viral protein expressing cells. AHSV proteins were successfully expressed in E. coli using the pET102/D-TOPO expression vector and the effector cells were stimulated with these recombinant proteins or with live viable virulent AHSV4. The AHSV genes were amplified and cloned into the pIRES-hrGFP II (pGFPempty) vector and these plasmid vectors encoding antigen-green fluorescent protein (GFP) fusion proteins were used to nucleofect PBMC, the target cells. The elimination of antigen-GFP expressing cells by CTL was quantified by flowcytometry. VP1-1, VP2-2, VP4, VP7 and NS3, antigen-specific CD8+ T cells resulted in cell lysis suggesting that CTL may play a role in the immune response induced against the AHSV4 vaccine strain. PMID:27063332
Molecular analysis and associated pathology of beak and feather disease virus isolated in Italy from young Congo African grey parrots (Psittacus erithacus) with an "atypical peracute form" of the disease.
Robino, Patrizia; Grego, Elena; Rossi, Giacomo; Bert, Elena; Tramuta, Clara; Stella, Maria Cristina; Bertoni, Pierfrancesco; Nebbia, Patrizia
This study is the first report on the genetic and pathogenic characterization of beak and feather disease virus (BFDV) occurring in Italy. Twenty BFDV strains isolated in Italy from juvenile Congo African grey parrots (Psittacus erithacus) were investigated. Seventeen strains showed an "atypical peracute form" (aPF) of the disease, and three a chronic form (CF). The birds with aPF had been weaned, were independent as far as food and protection were concerned and apparently were without lesions. The gene coding for the putative coat protein was amplified in all isolates while the BFDV genome was sequenced completely in 10 samples, eight of them belonging to aPF affected birds and two from CF of the disease. All full genomes clustered into the J strain of BFDV, where two new subtypes were identified. Recombination analyses showed evidence of genetic exchanges in two BFDV genomes. In addition, a correlation between viral isolate and origin of the breeding material was shown, while an association between the genetic features of the virus and the clinical form was not observed. Histologically, apoptosis was detected frequently in aPF samples and sporadically in CF samples. Interestingly, BFDV antigens were detected in the nuclei and cytoplasm of such apoptotic cells. The data presented here support the hypothesis that, in the absence of a defined BFDV genetic variant accountable for a specific clinical form of psittacine beak and feather disease, differences in the apoptotic rate between aPF and CF are strictly host related.
Molecular analysis and associated pathology of beak and feather disease virus isolated in Italy from young Congo African grey parrots (Psittacus erithacus) with an "atypical peracute form" of the disease.
Robino, Patrizia; Grego, Elena; Rossi, Giacomo; Bert, Elena; Tramuta, Clara; Stella, Maria Cristina; Bertoni, Pierfrancesco; Nebbia, Patrizia
This study is the first report on the genetic and pathogenic characterization of beak and feather disease virus (BFDV) occurring in Italy. Twenty BFDV strains isolated in Italy from juvenile Congo African grey parrots (Psittacus erithacus) were investigated. Seventeen strains showed an "atypical peracute form" (aPF) of the disease, and three a chronic form (CF). The birds with aPF had been weaned, were independent as far as food and protection were concerned and apparently were without lesions. The gene coding for the putative coat protein was amplified in all isolates while the BFDV genome was sequenced completely in 10 samples, eight of them belonging to aPF affected birds and two from CF of the disease. All full genomes clustered into the J strain of BFDV, where two new subtypes were identified. Recombination analyses showed evidence of genetic exchanges in two BFDV genomes. In addition, a correlation between viral isolate and origin of the breeding material was shown, while an association between the genetic features of the virus and the clinical form was not observed. Histologically, apoptosis was detected frequently in aPF samples and sporadically in CF samples. Interestingly, BFDV antigens were detected in the nuclei and cytoplasm of such apoptotic cells. The data presented here support the hypothesis that, in the absence of a defined BFDV genetic variant accountable for a specific clinical form of psittacine beak and feather disease, differences in the apoptotic rate between aPF and CF are strictly host related. PMID:24968067
Matsephe M. Letseka
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.
Coffey, L. L.; Vignuzzi, M.
The mechanisms by which RNA arboviruses, including chikungunya virus (CHIKV), evolve and maintain the ability to infect vertebrate and invertebrate hosts are poorly understood. To understand how host specificity shapes arbovirus populations, we studied CHIKV populations passaged alternately between invertebrate and vertebrate cells (invertebrate ↔ vertebrate) to simulate natural alternation and contrasted the results with those for populations that were artificially released from cycling by p...
Fournier, Carole; Helle, François; Descamps, Véronique; Morel, Virginie; François, Catherine; Dedeurwaerder, Sarah; Wychowski, Czeslaw; Duverlie, Gilles; Castelain, Sandrine
A trans-packaging system for hepatitis C virus (HCV) replicons lacking envelope glycoproteins was developed. The replicons were efficiently encapsidated into infectious particles after expression in trans of homologous HCV envelope proteins under the control of an adenoviral vector. Interestingly, expression in trans of core or core, p7 and NS2 with envelope proteins did not enhance trans-encapsidation. Expression of heterologous envelope proteins, in the presence or absence of heterologous core, p7 and NS2, did not rescue single-round infectious particle production. To increase the titre of homologous, single-round infectious particles in our system, successive cycles of trans-encapsidation and infection were performed. Four cycles resulted in a 100-fold increase in the yield of particles. Sequence analysis revealed a total of 16 potential adaptive mutations in two independent experiments. Except for a core mutation in one experiment, all the mutations were located in non-structural regions mainly in NS5A (four in domain III and two near the junction with the NS5B gene). Reverse genetics studies suggested that D2437A and S2443T adaptive mutations, which are located at the NS5A-B cleavage site did not affect viral replication, but enhanced the single-round infectious particles assembly only in trans-encapsidation model. In conclusion, our trans-encapsidation system enables the production of HCV single-round infectious particles. This system is adaptable and can positively select variants. The adapted variants promote trans-encapsidation and should constitute a valuable tool in the development of replicon-based HCV vaccines. PMID:23288424
The cold adapted and temperature sensitive influenza A/Ann Arbor/6/60 virus, the master donor virus for live attenuated influenza vaccines, has multiple defects in replication at the restrictive temperature
We have previously determined that the temperature sensitive (ts) and attenuated (att) phenotypes of the cold adapted influenza A/Ann Arbor/6/60 strain (MDV-A), the master donor virus for the live attenuated influenza A vaccines (FluMist), are specified by the five amino acids in the PB1, PB2 and NP gene segments. To understand how these loci control the ts phenotype of MDV-A, replication of MDV-A at the non-permissive temperature (39 deg. C) was compared with recombinant wild-type A/Ann Arbor/6/60 (rWt). The mRNA and protein synthesis of MDV-A in the infected MDCK cells were not significantly reduced at 39 deg. C during a single-step replication, however, vRNA synthesis was reduced and the nuclear-cytoplasmic export of viral RNP (vRNP) was blocked. In addition, the virions released from MDV-A infected cells at 39 deg. C exhibited irregular morphology and had a greatly reduced amount of the M1 protein incorporated. The reduced M1 protein incorporation and vRNP export blockage correlated well with the virus ts phenotype because these defects could be partially alleviated by removing the three ts loci from the PB1 gene. The virions and vRNPs isolated from the MDV-A infected cells contained a higher level of heat shock protein 70 (Hsp70) than those of rWt, however, whether Hsp70 is involved in thermal inhibition of MDV-A replication remains to be determined. Our studies demonstrate that restrictive replication of MDV-A at the non-permissive temperature occurs in multiple steps of the virus replication cycle
... Population Profiles > Black/African American > Cancer Cancer and African Americans African Americans have the highest mortality rate ... 65MB] At a glance – Top Cancer Sites for African Americans (2008-2012) Cancer Incidence Rates per 100, ...
Ellen R. T. Watkiss
Full Text Available Respiratory syncytial virus (RSV is the leading cause of infant bronchiolitis. The closely related pneumonia virus of mice (PVM causes a similar immune-mediated disease in mice, which allows an analysis of host factors that lead to severe illness. This project was designed to compare the immune responses to lethal and sublethal doses of PVM strain 15 in Balb/c and C57Bl/6 mice. Balb/c mice responded to PVM infection with an earlier and stronger innate response that failed to control viral replication. Production of inflammatory cyto- and chemokines, as well as infiltration of neutrophils and IFN-γ secreting natural killer cells into the lungs, was more predominant in Balb/c mice. In contrast, C57Bl/6 mice were capable of suppressing both viral replication and innate inflammatory responses. After a sublethal infection, PVM-induced IFN-γ production by splenocytes was stronger early during infection and weaker at late time points in C57Bl/6 mice when compared to Balb/c mice. Furthermore, although the IgG levels were similar and the mucosal IgA titres lower, the virus neutralizing antibody titres were higher in C57Bl/6 mice than in Balb/c mice. Overall, the difference in susceptibility of these two strains appeared to be related not to an inherent T helper bias, but to the capacity of the C57Bl/6 mice to control both viral replication and the immune response elicited by PVM.
Moncef Boulila; Sawssen Ben Tiba; Saoussen Jilani
The sequence alignments of five Tunisian isolates of Prunus necrotic ringspot virus (PNRSV) were searched for evidence of recombination and diversifying selection. Since failing to account for recombination can elevate the false positive error rate in positive selection inference, a genetic algorithm (GARD) was used first and led to the detection of potential recombination events in the coat protein-encoding gene of that virus. The Recco algorithm confirmed these results by identifying, additionally, the potential recombinants. For neutrality testing and evaluation of nucleotide polymorphism in PNRSV CP gene, Tajima’s , and Fu and Li’s and statistical tests were used. About selection inference, eight algorithms (SLAC, FEL, IFEL, REL, FUBAR, MEME, PARRIS, and GA branch) incorporated in HyPhy package were utilized to assess the selection pressure exerted on the expression of PNRSV capsid. Inferred phylogenies pointed out, in addition to the three classical groups (PE-5, PV-32, and PV-96), the delineation of a fourth cluster having the new proposed designation SW6, and a fifth clade comprising four Tunisian PNRSV isolates which underwent recombination and selective pressure and to which the name Tunisian outgroup was allocated.
Kresfelder, T. L.; Janssen, R.; Bont, L.; Venter, M.
Respiratory syncytial virus is a leading cause of lower respiratory tract infection in infants. Disease severity has been linked to host immune responses and polymorphisms in genes associated with innate immunity. A large-scale genetics study of single nucleotide polymorphisms (SNPs) in children in
Paraskevis, Dimitrios; Angelis, Konstantinos; Magiorkinis, Gkikas; Kostaki, Evangelia; Ho, Simon Y W; Hatzakis, Angelos
The evolution of hepatitis B virus (HBV), particularly its origins and evolutionary timescale, has been the subject of debate. Three major scenarios have been proposed, variously placing the origin of HBV in humans and great apes from some million years to only a few thousand years ago (ka). To compare these scenarios, we analyzed 105 full-length HBV genome sequences from all major genotypes sampled globally. We found a high correlation between the demographic histories of HBV and humans, as well as coincidence in the times of origin of specific subgenotypes with human migrations giving rise to their host indigenous populations. Together with phylogenetic evidence, this suggests that HBV has co-expanded with modern humans. Based on the co-expansion, we conducted a Bayesian dating analysis to estimate a precise evolutionary timescale for HBV. Five calibrations were used at the origins of F/H genotypes, D4, C3 and B6 from respective indigenous populations in the Pacific and Arctic and A5 from Haiti. The estimated time for the origin of HBV was 34.1ka (95% highest posterior density interval 27.6-41.3ka), coinciding with the dispersal of modern non-African humans. Our study, the first to use full-length HBV sequences, places a precise timescale on the HBV epidemic and also shows that the "branching paradox" of the more divergent genotypes F/H from Amerindians is due to an accelerated substitution rate, probably driven by positive selection. This may explain previously observed differences in the natural history of HBV between genotypes F1 and A2, B1, and D.
Shabala, Sergey; Bækgaard, Lone; Shabala, Lana;
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...... for practical applications in agriculture, after in-depth comprehension of the fundamental mechanisms involved in common responses to environmental factors at the genomic, cellular and organismal levels....
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.
Kerr, Peter J; Rogers, Matthew B; Fitch, Adam; Depasse, Jay V; Cattadori, Isabella M; Hudson, Peter J; Tscharke, David C; Holmes, Edward C; Ghedin, Elodie
Myxomatosis is a rapidly lethal disease of European rabbits that is caused by myxoma virus (MYXV). The introduction of a South American strain of MYXV into the European rabbit population of Australia is the classic case of host-pathogen coevolution following cross-species transmission. The most virulent strains of MYXV for European rabbits are the Californian viruses, found in the Pacific states of the United States and the Baja Peninsula, Mexico. The natural host of Californian MYXV is the brush rabbit, Sylvilagus bachmani. We determined the complete sequence of the MSW strain of Californian MYXV and performed a comparative analysis with other MYXV genomes. The MSW genome is larger than that of the South American Lausanne (type) strain of MYXV due to an expansion of the terminal inverted repeats (TIRs) of the genome, with duplication of the M156R, M154L, M153R, M152R, and M151R genes and part of the M150R gene from the right-hand (RH) end of the genome at the left-hand (LH) TIR. Despite the extreme virulence of MSW, no novel genes were identified; five genes were disrupted by multiple indels or mutations to the ATG start codon, including two genes, M008.1L/R and M152R, with major virulence functions in European rabbits, and a sixth gene, M000.5L/R, was absent. The loss of these gene functions suggests that S. bachmani is a relatively recent host for MYXV and that duplication of virulence genes in the TIRs, gene loss, or sequence variation in other genes can compensate for the loss of M008.1L/R and M152R in infections of European rabbits. PMID:23986601
Mathiesen, Christian K.; Prentoe, Jannick; Meredith, Luke W.;
requiring high virus concentrations, such as studies of HCV particle composition and development of whole-virus vaccine antigens. IMPORTANCE: Hepatitis C virus (HCV) is a major global health care burden, affecting more than 150 million people worldwide. These individuals are at high risk of developing......UNLABELLED: Recombinant hepatitis C virus (HCV) clones propagated in human hepatoma cell cultures yield relatively low infectivity titers. Here, we adapted the JFH1-based Core-NS2 recombinant SA13/JFH1C3405G,A3696G (termed SA13/JFH1orig), of the poorly characterized genotype 5a, to Huh7.5 cells......, yielding a virus with greatly improved spread kinetics and an infectivity titer of 6.7 log10 focus-forming units (FFU)/ml. We identified several putative adaptive amino acid changes. In head-to-head infections at fixed multiplicities of infection, one SA13/JFH1orig mutant termed SA13/JFH1Core-NS5B...
The RE Open will be shown at the Mall Gallery London and the international section was judged by major practitioners and educators, print dealers and collectors, President of RE and Keeper of the Ashmolean Museum Dr Bren Unwin, John Purcell, Deborah Roslund, Colin Harrison, Dave Ferry, and Mark Hampson. Piece selected "African Dance" print.
Adelman, Cathy; And Others
This interdisciplinary unit provides students in grades kindergarten through seventh grade an opportunity to understand diversity through a study of Africa as a diverse continent. The project is designed to provide all elementary students with cultural enrichment by exposing them to African music, art, storytelling, and movement. This project can…
Ghsa Preparation Task Force Team
The Ebola virus disease outbreak in West Africa and the Middle East Respiratory Syndrome outbreak in the Republic of Korea have given huge impacts in different aspects. Health security is no more a new coinage. Global health security became more realistic in its practical application. In the perspective of global health, it will be helpful to peruse lessons learned from the Ebola outbreak in West Africa and MERS outbreak in Korea. PMID:27429901
Full Text Available Fingolimod, an oral sphingosine 1-phosphate (S1P receptor modulator, is approved for the treatment of relapsing forms of multiple sclerosis (MS. The interference with S1P signaling leads to retention particularly of chemokine receptor-7 (CCR7 expressing T cells in lymph nodes. The immunological basis of varicella zoster virus (VZV infections during fingolimod treatment is unclear. Here, we studied the dynamics of systemic and intrathecal immune responses associated with symptomatic VZV reactivation including cessation of fingolimod and initiation of antiviral therapy. Key features in peripheral blood were an about two-fold increase of VZV-specific IgG at diagnosis of VZV reactivation as compared to the previous months, a relative enrichment of effector CD4+ T cells (36% versus mean 12% in controls, and an accelerated reconstitution of absolute lymphocytes counts including a normalized CD4+/CD8+ ratio and reappearance of CCR7+ T cells. In cerebrospinal fluid (CSF the lymphocytic pleocytosis and CD4+/CD8+ ratios at diagnosis of reactivation and after nine days of fingolimod discontinuation remained unchanged. During this time CCR7+ T cells were not observed in CSF. Further research into fingolimod-associated VZV reactivation and immune reconstitution is mandatory to prevent morbidity and mortality associated with this potentially life-threatening condition.
Svanella-Dumas, Laurence; Verdin, Eric; Faure, Chantal; German-Retana, Sylvie; Gognalons, Patrick; Danet, Jean Luc; Marais, Armelle; Candresse, Thierry
An isolate of Lettuce mosaic virus (LMV, a Potyvirus) infecting Madagascar periwinckle (Catharanthus roseus) was identified and characterized by Illumina deep sequencing. LMV-Cr has no close affinities to previously sequenced LMV isolates and represents a novel, divergent LMV clade. Inoculation experiments with other representative LMV isolates showed that they are unable to infect C. roseus, which was not known to be a host for LMV. However, three C. roseus variants of one of these isolates, LMV-AF199, could be selected and partially or completely sequenced. These variants are characterized by the accumulation of mutations affecting the C-terminal part of the cylindrical inclusion (CI) helicase and the central part of the VPg. In particular, a serine to proline mutation at amino acid 143 of the VPg was observed in all three independently selected variants and is also present in the LMV-Cr isolate, making it a prime candidate as a host-range determinant. Other mutations at VPg positions 65 and 144 could also contribute to the ability to infect C. roseus. Inoculation experiments involving a recombinant LMV expressing a permissive lettuce eukaryotic translation initiation factor 4E (eIF4E) suggest that eIF4E does not contribute to the interaction of most LMV isolates with C. roseus. PMID:24400938
Diagne, Cheikh T.; Faye, Oumar; Guerbois, Mathilde; Knight, Rachel; Diallo, Diawo; Ba, Yamar; Dia, Ibrahima; Faye, Ousmane; Weaver, Scott C.; Sall, Amadou A; Diallo, Mawlouth
To assess the risk of emergence of chikungunya virus (CHIKV) in West Africa, vector competence of wild-type, urban, and non-urban Aedes aegypti and Ae. vittatus from Senegal and Cape Verde for CHIKV was investigated. Mosquitoes were fed orally with CHIKV isolates from mosquitoes (ArD30237), bats (CS13-288), and humans (HD180738). After 5, 10, and 15 days of incubation following an infectious blood meal, presence of CHIKV RNA was determined in bodies, legs/wings, and saliva using real-time rev...
Doniņa, Simona; Strēle, Ieva; Proboka, Guna; Auziņš, Jurgis; Alberts, Pēteris; Jonsson, Björn; Venskus, Dite; Muceniece, Aina
An oncolytic, nonpathogenic ECHO-7 virus adapted for melanoma that has not been genetically modified (Rigvir) is approved and registered for virotherapy, an active and specific immunotherapy, in Latvia since 2004. The present retrospective study was carried out to determine the effectiveness of Rigvir in substage IB, IIA, IIB and IIC melanoma patients on time to progression and overall survival. White patients (N=79) who had undergone surgical excision of the primary melanoma tumour were included in this study. All patients were free from disease after surgery and classified into substages IB, IIA, IIB and IIC. Circulating levels of clinical chemistry parameters were recorded. Survival was analysed by Cox regression. Rigvir significantly (PRigvir was statistically significantly different: hazard ratio 6.27 for all, 4.39 for substage IIA-IIB-IIC and 6.57 for substage IIB-IIC patients. The follow-up period was not statistically different between both treatment groups. These results indicate that the patients treated with Rigvir had a 4.39-6.57-fold lower mortality than those under observation. In this study, there was no untoward side effect or discontinuation of Rigvir treatment. Safety assessment of adverse events graded according to NCI CTCAE did not show any value above grade 2 in Rigvir-treated patients. In conclusion, Rigvir significantly prolongs survival in early-stage melanoma patients without any side effect. PMID:26193376
Mellor, Philip Scott; Hamblin, Christopher
African horse sickness virus (AHSV) causes a non-contagious, infectious insect-borne disease of equids and is endemic in many areas of sub-Saharan Africa and possibly Yemen in the Arabian Peninsula. However, periodically the virus makes excursions beyond its endemic areas and has at times extended as far as India and Pakistan in the east and Spain and Portugal in the west. The vectors are certain species of Culicoides biting midge the most important of which is the Afro-Asiatic species C. imicola. This paper describes the effects that AHSV has on its equid hosts, aspects of its epidemiology, and present and future prospects for control. The distribution of AHSV seems to be governed by a number of factors including the efficiency of control measures, the presence or absence of a long term vertebrate reservoir and, most importantly, the prevalence and seasonal incidence of the major vector which is controlled by climate. However, with the advent of climate-change the major vector, C. imicola, has now significantly extended its range northwards to include much of Portugal, Spain, Italy and Greece and has even been recorded from southern Switzerland. Furthermore, in many of these new locations the insect is present and active throughout the entire year. With the related bluetongue virus, which utilises the same vector species of Culicoides this has, since 1998, precipitated the worst outbreaks of bluetongue disease ever recorded with the virus extending further north in Europe than ever before and apparently becoming endemic in that continent. The prospects for similar changes in the epidemiology and distribution of AHSV are discussed.
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  we obtained resistance values of the codling moth, Cydia pomonella, RGV laboratory colony , when challenged with Cydia pomonella Granulovirus, Mexican Isolate (CpGV-M, that were lower than those previously published . 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.
Quantification of Human T-lymphotropic virus type I (HTLV-I) provirus load in a rural West African population: no enhancement of human immunodeficiency virus type 2 pathogenesis, but HTLV-I provirus load relates to mortality
Ariyoshi, K; Berry, N; Cham, F;
Human T-lymphotropic virus type I (HTLV-I) provirus load was examined in a cohort of a population in Guinea-Bissau among whom human immunodeficiency virus (HIV) type 2 is endemic. Geometric mean of HIV-2 RNA load among HTLV-I-coinfected subjects was significantly lower than that in subjects...... infected with HIV-2 alone (212 vs. 724 copies/mL; P=.02). Adjusted for age, sex, and HIV status, the risk of death increased with HTLV-I provirus load; mortality hazard ratio was 1.59 for each log10 increase in HTLV-I provirus copies (P=.038). There is no enhancing effect of HTLV-I coinfection on HIV-2...
Full Text Available It has been said that 'Necessity is the mother of invention' and there can be few countries, if any, where this is more true than in South Africa.In the late 1930's, prior to World War II, the South African Artillery was severely restricted due to its lack of mobility. The inventiveness shown in tackling this probelm is surely not a thing of the past and the possiblity of adapting South African artillery to current South african needs in warfare should not be overlooked. The South African Defence Force is not able to purchase armament in a free and open market place and the costs of developing new artillery are prohibitive in a country of South Africa's size. it will be argued that it is necessary and possible, in the short term, to take what is currently available and adapt this to South Africa's needs.
... Data > Minority Population Profiles > Black/African American > Obesity Obesity and African Americans African American women have the ... ss6304.pdf [PDF | 3.38MB] HEALTH IMPACT OF OBESITY More than 80 percent of people with type ...
M.W.G. van de Bildt (Marco); T. Kuiken (Thijs); A.M. Visee; S. Lema; A.R. Fitzjohn; A.D.M.E. Osterhaus (Albert)
textabstractIn December 2000, an infectious disease spread through a captive breeding group of African wild dogs (Lycaon pictus) in Tanzania, killing 49 of 52 animals within 2 months. The causative agent was identified as Canine distemper virus (CDV) by means of histologic examination, virus isolati
Nazimek, Katarzyna; Bociaga-Jasik, Monika; Bryniarski, Krzysztof; Gałas, Aleksander; Garlicki, Aleksander; Gawda, Anna; Gawlik, Grzegorz; Gil, Krzysztof; Kosz-Vnenchak, Magdalena; Mrozek-Budzyn, Dorota; Olszanecki, Rafał; Piatek, Anna; Zawilińska, Barbara; Marcinkiewicz, Janusz
Ebola is one of the most virulent zoonotic RNA viruses causing in humans haemorrhagic fever with fatality ratio reaching 90%. During the outbreak of 2014 the number of deaths exceeded 8.000. The "imported" cases reported in Western Europe and USA highlighted the extreme risk of Ebola virus spreading outside the African countries. Thus, haemorrhagic fever outbreak is an international epidemiological problem, also due to the lack of approved prevention and therapeutic strategies. The editorial review article briefly summarizes current knowledge on Ebola virus disease epidemiology, etiology, pathogenesis, clinical presentation, diagnosis as well as possible prevention and treatment.
Diagne, Cheikh T; Faye, Oumar; Guerbois, Mathilde; Knight, Rachel; Diallo, Diawo; Faye, Ousmane; Ba, Yamar; Dia, Ibrahima; Faye, Ousmane; Weaver, Scott C; Sall, Amadou A; Diallo, Mawlouth
To assess the risk of emergence of chikungunya virus (CHIKV) in West Africa, vector competence of wild-type, urban, and non-urban Aedes aegypti and Ae. vittatus from Senegal and Cape Verde for CHIKV was investigated. Mosquitoes were fed orally with CHIKV isolates from mosquitoes (ArD30237), bats (CS13-288), and humans (HD180738). After 5, 10, and 15 days of incubation following an infectious blood meal, presence of CHIKV RNA was determined in bodies, legs/wings, and saliva using real-time reverse transcription-polymerase chain reaction. Aedes vittatus showed high susceptibility (50-100%) and early dissemination and transmission of all CHIKV strains tested. Aedes aegypti exhibited infection rates ranging from 0% to 50%. Aedes aegypti from Cape Verde and Kedougou, but not those from Dakar, showed the potential to transmit CHIKV in saliva. Analysis of biology and competence showed relatively high infective survival rates for Ae. vittatus and Ae. aegypti from Cape Verde, suggesting their efficient vector capacity in West Africa. PMID:25002293
Holzer, Barbara; Taylor, Geraldine; Rajko-Nenow, Paulina; Hodgson, Sophia; Okoth, Edward; Herbert, Rebecca; Toye, Philip; Baron, Michael D
Peste des petits ruminants virus (PPRV) causes an economically important disease of sheep and goats, primarily in developing countries. It is becoming the object of intensive international control efforts. Current vaccines do not allow vaccinated and infected animals to be distinguished (no DIVA capability). We have previously shown that recombinant, replication-defective, adenovirus expressing the PPRV H glycoprotein (AdH) gives full protection against wild type PPRV challenge. We have now tested lower doses of the vaccine, as well as AdH in combination with a similar construct expressing the PPRV F glycoprotein (AdF). We show here that, in a local breed of goat in a country where PPR disease is common (Kenya), as little as 10(7) pfu of AdH gives significant protection against PPRV challenge, while a vaccine consisting of 10(8) pfu of each of AdH and AdF gives apparently sterile protection. These findings underline the utility of these constructs as DIVA vaccines for use in PPR control. PMID:26796101
Tsetsarkin, Konstantin A; Chen, Rubing; Weaver, Scott C
Chikungunya virus (CHIKV) causes severe, debilitating, often chronic arthralgia with high attack rates, resulting in severe morbidity and economic costs to affected communities. Since its first well-documented emergence in Asia in the 1950s, CHIKV has infected millions and, since 2007, has spread widely, probably via viremic travelers, to initiate urban transmission in Europe, the South Pacific, and the Americas. Some spread has been facilitated by adaptive envelope glycoprotein substitutions that enhance transmission by the new vector, Aedes albopictus. Although epistatic constraints may prevent the impact of these mutations in Asian strains now circulating in the Americas, as well as in African CHIKV strains imported into Brazil last year, these constraints could eventually be overcome over time to increase the transmission by A. albopictus in rural and temperate regions. Another major determinant of CHIKV endemic stability in the Americas will be its ability to spill back into an enzootic cycle involving sylvatic vectors and nonhuman primates, an opportunity exploited by yellow fever virus but apparently not by dengue viruses. PMID:26986235
Lynd, Lee R; Sow, Mariam; Chimphango, Annie Fa; Cortez, Luis Ab; Brito Cruz, Carlos H; Elmissiry, Mosad; Laser, Mark; Mayaki, Ibrahim A; Moraes, Marcia Afd; Nogueira, Luiz Ah; Wolfaardt, Gideon M; Woods, Jeremy; van Zyl, Willem H
Among the world's continents, Africa has the highest incidence of food insecurity and poverty and the highest rates of population growth. Yet Africa also has the most arable land, the lowest crop yields, and by far the most plentiful land resources relative to energy demand. It is thus of interest to examine the potential of expanded modern bioenergy production in Africa. Here we consider bioenergy as an enabler for development, and provide an overview of modern bioenergy technologies with a comment on application in an Africa context. Experience with bioenergy in Africa offers evidence of social benefits and also some important lessons. In Brazil, social development, agricultural development and food security, and bioenergy development have been synergistic rather than antagonistic. Realizing similar success in African countries will require clear vision, good governance, and adaptation of technologies, knowledge, and business models to myriad local circumstances. Strategies for integrated production of food crops, livestock, and bioenergy are potentially attractive and offer an alternative to an agricultural model featuring specialized land use. If done thoughtfully, there is considerable evidence that food security and economic development in Africa can be addressed more effectively with modern bioenergy than without it. Modern bioenergy can be an agent of African transformation, with potential social benefits accruing to multiple sectors and extending well beyond energy supply per se. Potential negative impacts also cut across sectors. Thus, institutionally inclusive multi-sector legislative structures will be more effective at maximizing the social benefits of bioenergy compared to institutionally exclusive, single-sector structures.
Dadonaite, Bernadeta; Vijyakrishnan, Swetha; Fodor, Ervin; Bhella, David; Hutchinson, Edward C.
Clinical isolates of influenza virus produce pleomorphic virus particles, including extremely long filamentous virions. In contrast, strains of influenza that have adapted to laboratory growth typically produce only spherical virions. As a result, the filamentous phenotype has been overlooked in most influenza virus research. Recent advances in imaging and improved animal models have highlighted the distinct structure and functional relevance of filamentous virions. In this review we summaris...
Bovine viral diarrhea viruses (BVDV) are most commonly associated with infections of cattle. However, BVDV is often isolated from closely related ruminants with a number of BVDV-1b viruses being isolated from alpacas that were both acutely and persistently infected (PI). The complete nucleotide se...
A. R. Rekstin
Full Text Available While investigating the efficacy of an H5N2 ca reassortant vaccine candidate in protecting against a lethal challenge with a highly pathogenic (HP H5N1 virus in the mouse model, we observed a degree of cross-protection provided by the ca Len/17 (H2N2 virus itself. 80% of mice administered a high dose of attenuated Len/17 vaccine intranasally (i.n. survived after a lethal challenge with A/Hong Kong/483/97 H5N1 virus. Therefore, we investigated the basis of the cross- reactive immunity between H2N2 and H5N1 viruses that may have contributed to recovery from lethal HK/ 483 virus infection. Sera from mice immunized i.n. with Len/17 did not cross-react with HK/483 virus in neutralization or hemagglutination-inhibition assays, however IgG and IgA antibodies that cross-reacted with the hemagglutinin and neuraminidase of H5N1 1997 viruses were detected. Spleen cells from mice immunized i.n. with Len/17 vaccine showed enhanced production of IL-2, IL-4, IL-5, IL-10, and IFNγ following in vitro stimulation with inactivated H5N1 virus. Our findings indicate that both cross-reactive humoral and cellular immunity induced by Len/17 H2N2 vaccine may plays a role in recovery from lethal H5N1 virus infection. A better understanding of the mechanisms of heterosubtypic immunity will improve vaccine design against HP avian influenza viruses.
Calvo, María; Malinowski, Tadeusz; García, Juan Antonio
Plum pox virus (PPV) C is one of the less common PPV strains and specifically infects cherry trees in nature. Making use of two PPV-C isolates that display different pathogenicity features, i.e., SwCMp, which had been adapted to Nicotiana species, and BY101, which had been isolated from cherry rootstock L2 (Prunus lannesiana) and propagated only in cherry species, we have generated two infective full-length cDNA clones in order to determine which viral factors are involved in the adaptation to each host. According to our results, the C-P3(PIPO)/6K1/N-CI (cylindrical inclusion) region contains overlapping but not coincident viral determinants involved in symptoms development, local viral amplification, and systemic movement capacity. Amino acid changes in this region promoting the adaptation to N. benthamiana or P. avium have trade-off effects in the alternative host. In both cases, adaptation can be achieved through single amino acid changes in the NIapro protease recognition motif between 6K1 and CI or in nearby sequences. Thus, we hypothesize that the potyvirus polyprotein processing could depend on specific host factors and the adaptation of PPV-C isolates to particular hosts relies on a fine regulation of the proteolytic cleavage of the 6K1-CI junction. PMID:24200075
Gullberg, Maria; Polacek, Charlotta; Belsham, Graham
, introduction of the 2A L2P substitution alone, or with the VP1 K210E change, into this virus resulted in the production of viable viruses. Cells infected with viruses containing the VP1 K210E and/or the 2A L2P substitutions contained the uncleaved VP1-2A protein; the 2A L2P substitution rendered the VP1/2A......The foot-and-mouth disease virus (FMDV) capsid protein precursor P1-2A is cleaved by the 3C protease to produce VP0, VP3, VP1 and 2A. It was shown previously that modification of a single amino acid residue (K210) within the VP1 protein, close to the VP1/2A cleavage site, inhibited cleavage...... of this junction and resulted in the production of “self-tagged” virus particles containing the 2A peptide. A second site substitution (E83K) within VP1 was also observed within the rescued virus (Gullberg et al., 2013). It is now shown that introduction of this E83K change alone into a serotype O virus resulted...
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.
Li, Can; Li, Chuangen; Anna J X Zhang; To, Kelvin K. W.; Andrew C Y Lee; Zhu, Houshun; Wu, Hazel W. L.; Chan, Jasper F. W.; Chen, Honglin; Hung, Ivan F. N.; Li, Lanjuan; Yuen, Kwok-Yung
Background Human infection caused by the avian influenza A H7N9 virus has a case-fatality rate of over 30%. Systematic study of the pathogenesis of avian H7N9 isolate and effective therapeutic strategies are needed. Methods BALB/c mice were inoculated intranasally with an H7N9 virus isolated from a chicken in a wet market epidemiologically linked to a fatal human case, (A/chicken/Zhejiang/DTID-ZJU01/2013 [CK1]), and with an H7N9 virus isolated from a human (A/Anhui/01/2013 [AH1]). The pulmona...
... Minority Population Profiles > Black/African American > Heart Disease Heart Disease and African Americans Although African American adults are ... were 30 percent more likely to die from heart disease than non-Hispanic whites. African American women are ...
HE Hongjun; CAO Sihua; LUO Li; FENG Tao; PAN Li; ZOU Zhiji
Security experts have not formally defined the distinction between viruses and normal programs. The paper takes user's intension as the criteria for malice, gives a formal definition of viruses that aim at stealing or destroying files, and proposes an algorithm to detect virus correctly. Compared with traditional definitions, this new definition is easy to understand, covers more malwares, adapts development of virus technology, and defines virus on the spot. The paper has also analyzed more than 250 real viruses and finds that they are all in the domain of the new definition, this implies that the new definition has great practical significance.
Doyer, O.T.; Haese, D' M.F.C.; Rooyen, van C.J.; Kirsten, J.F.; Haese, D' L.
This article examines the changing governance structures in the South African agri-food sector. Changing legislative and market conditions forced agribusiness managers to rethink their governance structures to ensure the competitiveness of the agri-food sector. They had to adapt to the new structure
In a television broadcast, Deputy President Mbeki of South Africa announced a campaign against HIV/AIDS that would involve coordination between various government departments and nongovernmental organizations. Mbeki, who is associated with Virodene (a drug treatment for AIDS that is considered a scam), replaced President Mandela at the last minute in the broadcast. Two days after the broadcast, the government refused to support treatment of pregnant women infected with HIV with zidovudine to prevent transmission of the virus to the baby. The treatment is considered cost-effective by AIDS workers and public health officials. According to Mark Heywood of the AIDS law project at Witwatersrand University, 16% of pregnant women attending antenatal clinics were HIV-positive in 1997; this means that about 3 million South Africans (8% of the population) were living with HIV. Heywood said that the government believes there are 1500 new cases daily. By the end of 1998, 3.5 million South Africans will be living with HIV. Although the government is asking other sectors to join in the campaign, what the government is doing is unclear. Mother-to-child transmission of HIV is second only to transmission of the virus through heterosexual sex in South Africa. PMID:9841037
Lack of chicken adaptation of newly emergent Eurasian H5N8 and reassortant H5N2 high pathogenicity avian influenza viruses in the U.S. is consistent with restricted poultry outbreaks in the Pacific flyway during 2014-2015.
Bertran, Kateri; Swayne, David E; Pantin-Jackwood, Mary J; Kapczynski, Darrell R; Spackman, Erica; Suarez, David L
In 2014-2015, the U.S. experienced an unprecedented outbreak of Eurasian clade 126.96.36.199 H5 highly pathogenic avian influenza (HPAI) virus, initially affecting mainly wild birds and few backyard and commercial poultry premises. To better model the outbreak, the pathogenesis and transmission dynamics of representative Eurasian H5N8 and reassortant H5N2 clade 188.8.131.52 HPAI viruses detected early in the North American outbreak were investigated in chickens. High mean chicken infectious doses and lack of seroconversion in survivors indicated the viruses were poorly chicken adapted. Pathobiological features were consistent with HPAI virus infection, although the delayed appearance of lesions, longer mean death times, and reduced replication in endothelial cells differed from features of most other Eurasian H5N1 HPAI viruses. Although these initial U.S. H5 HPAI viruses had reduced adaptation and transmissibility in chickens, multi-generational passage in poultry could generate poultry adapted viruses with higher infectivity and transmissibility.
Lack of chicken adaptation of newly emergent Eurasian H5N8 and reassortant H5N2 high pathogenicity avian influenza viruses in the U.S. is consistent with restricted poultry outbreaks in the Pacific flyway during 2014-2015.
Bertran, Kateri; Swayne, David E; Pantin-Jackwood, Mary J; Kapczynski, Darrell R; Spackman, Erica; Suarez, David L
In 2014-2015, the U.S. experienced an unprecedented outbreak of Eurasian clade 184.108.40.206 H5 highly pathogenic avian influenza (HPAI) virus, initially affecting mainly wild birds and few backyard and commercial poultry premises. To better model the outbreak, the pathogenesis and transmission dynamics of representative Eurasian H5N8 and reassortant H5N2 clade 220.127.116.11 HPAI viruses detected early in the North American outbreak were investigated in chickens. High mean chicken infectious doses and lack of seroconversion in survivors indicated the viruses were poorly chicken adapted. Pathobiological features were consistent with HPAI virus infection, although the delayed appearance of lesions, longer mean death times, and reduced replication in endothelial cells differed from features of most other Eurasian H5N1 HPAI viruses. Although these initial U.S. H5 HPAI viruses had reduced adaptation and transmissibility in chickens, multi-generational passage in poultry could generate poultry adapted viruses with higher infectivity and transmissibility. PMID:27110710
Here we outline serious diseases of food and fiber animals that cause damaging economic effect on products all over the world. The only vector-borne DNA virus is included here, such as African swine fever virus, and the herpes viruses discussed have a complex epidemiology characterized by outbreak...
Prangishvili, D; Garrett, R A
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...
Gullberg, Maria; Polacek, Charlotta; Belsham, Graham
in the rapid accumulation of a second site substitution within the 2A sequence (L2P), which also blocked VP1/2A cleavage. This suggests a linkage between the E83K change in VP1 and cleavage of the VP1/2A junction. Cells infected with viruses containing the VP1 K210E or the 2A L2P substitutions contained......The foot-and-mouth disease virus (FMDV) capsid protein precursor P1-2A is cleaved by the virus-encoded 3C protease to VP0, VP3, VP1 and 2A. It was shown previously that modification of a single amino acid residue (K210E) within the VP1 protein and close to the VP1/2A cleavage site, inhibited...... cleavage of this junction and produced 'self-tagged' virus particles. A second site substitution (E83K) within VP1 was also observed within the rescued virus [Gullberg et al. (2013). J Virol 87: , 11591-11603]. It was shown here that introduction of this E83K change alone into a serotype O virus resulted...
... Vector-Borne Diseases (DVBD) NCEZID Share Compartir Heartland virus On this Page What is Heartland virus? How ... Do I Need to Know? What is Heartland virus? Heartland virus belongs to a family of viruses ...
... Involved News About Us Donate In This Section African Americans and Glaucoma email Send this article to ... glaucoma is the leading cause of blindness in African Americans. Half of those with glaucoma don't ...
Bekunda, M.; Galford, G. L.; Hickman, J. E.; Palm, C.
Africa's smallholder agricultural systems face unique challenges in planning for reducing poverty, concurrent with adaptation and mitigation to climate change. At continental level, policy seeks to promote a uniquely African Green Revolution to increase crop yields and food production, and improve local livelihoods. However, the consequences on the environment and climate are not clear; these pro-economic development measures should be linked to climate change adaptation and mitigation measures, and research is required to help achieve these policy proposals by identifying options, and testing impacts. In particular, increased nitrogen (N) inputs are essential for increasing food production in Africa, but are accompanied by inevitable increases in losses to the environment. These losses appear to be low at input levels promoted in agricultural development programs, while the increased N inputs both increase current food production and appear to reduce the vulnerability of food production to changes in climate. We present field and remote sensing evidence from Malawi that subsidizing improved seed and fertilizers increases resilience to drought without adding excess N to the environment. In Kenya, field research identified thresholds in N2O losses, where emissions are very low at fertilization rates of less than 200 kg ha-1. Village-scale models have identified potential inefficiencies in the food production process where the largest losses of reactive N occur, and which could be targeted to reduce the amount of N released to the environment. We further review some on-going research activities and progress in Africa that compare different methods of managing resources that target resilience in food production and adaptation to climate change, using nutrient N as an indicator, while evaluating the effects of these resource management practices on ecosystems and the environment.
African American Suicide Fact Sheet Based on 2012 Data (2014) Overview • In 2012, 2,357 African Americans completed suicide in the U.S. Of these, ... 46 per 100,000. • The suicide rate for African Americans ages 10-19 was 2.98 per ...
Responds to an article on aspects of African language policy and discusses the following issues: multilingualism and monolingualism, proposed changes in language policy from the Organization for African Unity and South African initiatives, the language of literature, bilingual education, and whose interests English-language teaching is serving.…
Full text: The effects of gamma radiation on foot-and-mouth disease virus in vitro and in situ have been studied. The data so far obtained show that a dose of 2 Mrad is required to inactivate virus in infected animal carcasses. But the dose may adversely affect the organoleptic quality of the meat. Experiments in vitro and in situ are necessary to study the effects of ionizing radiation on other viruses, such as rinderpest, swine fever and African swine fever-viruses, associated with animal products. Radiation may offer a possible means of eliminating the virus titre in many animal products and solve consequent quarantine problems. (author)
Rajmane, Yogesh; Shaikh, Sameer; Basha, Khalander; Reddy, G E C Vidyadhar; Nair, Soumya; Kamath, Sangita; Sreejesh, Greeshma; Rao, Harinarayana; Ramana, Venkata; Kumar, A S Manoj
AG129 mice are known to be permissive to infection by multiple serotypes of Dengue virus (DENV). There exists a concern that mouse passaged strains of the virus may induce neurological complications rather than increased vascular permeability in these mice, hence the use of human clinical isolates of the virus to develop the AG129 mouse model of Dengue disease with increased vascular permeability. The present study evaluated four mouse brain passaged DENV strains, each belonging to a different serotype and three of them having an original isolation history in India, for their suitability to serve as candidates to induce rapid lethal disease in AG129 mice. While all the viruses were able to establish a productive infection in the spleen, none of them induced paralysis despite their mouse brain passage history. Only the type-2 virus acquired the ability to induce a lethal disease after a single round of spleen to spleen passage, and became highly virulent after five more rounds. This apparently non-neurological lethal disease was characterized by high viral burden, elevated vascular permeability, serum TNF-α surge immediately before moribund stage, transient leukocytosis followed by severe leukopenia, lymphopenia throughout the course of the infection, and transient thrombocytopenia. The disease was also characterized by inflammatory splenic collapse during moribund stage, reminiscent of spontaneous splenic rupture reported in rare cases of severe Dengue in humans. PMID:23337909
赵玉娇; 龙海亭; 潘玥; 陈俊英; 杨丽娟; 岳耀斐; 孙强明
目的 研究Ⅳ型登革病毒中国株LD34在人胚肺二倍体细胞KMB17上的传代适应性及其生物学特性.方法 将Ⅳ型登革病毒中国株LD34在C6/36细胞上扩增,并采用微量细胞病变法测定病毒的感染性滴度.以2.0 MOI的病毒接种KMB17细胞传代培养,筛选KMB17细胞适应株,并进行培养条件的优化.将Ⅳ型登革病毒中国株LD34 KMB17细胞适应株连续传10代,测定病毒的感染性滴度,免疫荧光法检测病毒的抗原性,RT-PCR法扩增登革病毒的特异性基因.结果 筛选出的Ⅳ型登革病毒中国株LD34在KMB17细胞上的最佳培养条件为病毒接种MOI 0.4,培养基血清浓度5％;其感染KMB17细胞后可产生明显的细胞病变(CPE),连续传10代,病毒滴度达7.75 CCID50/ml;第10代病毒的抗原性呈阳性;第10代病毒能扩增出511 bp的登革病毒特异性基因和393 bp的Ⅳ型登革病毒特异性基因.结论 获得了Ⅳ型登革病毒中国株LD34 KMB17细胞适应株,病毒保持了原始毒株的基本生物学特性,且具有较好的抗原性.%Objective To investigate the adaptability of Dengue-Ⅳ virus LD34 strain, isolated in China, in KMB17 cells and the biological characteristics of adapted strain. Methods Dengue-Ⅳ LD34 strain was propagated in C6/36 cells and determined for infectivity, then inoculated to KMB17 cells at a MOI of 2.0 for subculture, based on which the adapted strain was screened, and the culture condition was optimized. The adapted strain was subcultured in KMB17 cells for 10 passages, then determined for infectious titer by microtitrimetry, and for antigenicity by IFA, from which the specific gene was amplified by RT-PCR. Results The optimal MOI and serum concentration in medium for culture of the screened adapted strain were 0. 4 and 5% respectively. The adapted strain caused obvious CPE of KMB17 cells , and reached a titer of 7. 75 CCID50/ml after subculture for 10 passages. The virus of passage 10 was positive for
Roditi, Isabel; Schumann, Gabriela; Naguleswaran, Arunasalam
African trypanosomes, which divide their life cycle between mammals and tsetse flies, are confronted with environments that differ widely in temperature, nutrient availability and host responses to infection. In particular, since trypanosomes cannot predict when they will be transmitted between hosts, it is vital for them to be able to sense and adapt to their milieu. Thanks to technical advances, significant progress has been made in understanding how the parasites perceive external stimuli and react to them. There is also a growing awareness that trypanosomes use a variety of mechanisms to exchange information with each other, thereby enhancing their chances of survival. PMID:27131101
Melon Chlorotic Leaf Curl Virus: Characterization and Differential Reassortment with Closest Relatives Reveal Adaptive Virulence in the Squash Leaf Curl Virus Clade and Host Shifting by the Host-Restricted Bean Calico Mosaic Virus▿
Idris, A. M.; Mills-Lujan, K.; Martin, K; Brown, J K
The genome components of the Melon chlorotic leaf curl virus (MCLCuV) were cloned from symptomatic cantaloupe leaves collected in Guatemala during 2002. The MCLCuV DNA-A and DNA-B components shared their closest nucleotide identities among begomoviruses, at ∼90 and 81%, respectively, with a papaya isolate of MCLCuV from Costa Rica. The closest relatives at the species level were other members of the Squash leaf curl virus (SLCV) clade, which is endemic in the southwestern United States and Me...
Saiz, Juan-Carlos; Vázquez-Calvo, Ángela; Blázquez, Ana B.; Merino-Ramos, Teresa; Escribano-Romero, Estela; Martín-Acebes, Miguel A.
Since the beginning of this century, humanity has been facing a new emerging, or re-emerging, virus threat almost every year: West Nile, Influenza A, avian flu, dengue, Chikungunya, SARS, MERS, Ebola, and now Zika, the latest newcomer. Zika virus (ZIKV), a flavivirus transmitted by Aedes mosquitoes, was identified in 1947 in a sentinel monkey in Uganda, and later on in humans in Nigeria. The virus was mainly confined to the African continent until it was detected in south-east Asia the 1980’s...
Juan-Carlos eSaiz; Angela eVazquez-Calvo; Ana Belen Blazquez; Teresa eMerino-Ramos; Estela eEscribano-Romero; Martín-Acebes, Miguel A.
Since the beginning of this century, humanity has been facing a new emerging, or re-emerging, virus threat almost every year: West Nile, Influenza A, avian flu, dengue, Chikungunya, SARS, MERS, Ebola, and now Zika, the latest newcomer. Zika virus (ZIKV), a flavivirus transmitted by Aedes mosquitoes, was identified in 1947 in a sentinel monkey in Uganda, and later on in humans in Nigeria. The virus was mainly confined to the African continent until it was detected in south-east Asia the 1980´s...
van de Bildt, Marco; Kuiken, Thijs; Visee, A.M.; Lema, S.; Fitzjohn, A.R.; Osterhaus, Albert
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 isolation, reverse transcriptase-polymerase chain reaction analysis, and nucleotide sequencing. This report emphasizes the importance of adequate protection against infectious diseases for the successful ...
Isolator piglets infected with porcine reproductive and respiratory syndrome virus (PRRSV) develop severe hypergammaglobulinemia, lymph node adenopathy and autoimmune disease. The expanded B cell clones in this disease are unusual in bearing hydrophobic HCDR3 regions and these are disseminated to mo...
Lorena Itatí Ibañez
Full Text Available The ectodomain of influenza A matrix protein 2 (M2e is a candidate for a universal influenza A vaccine. We used recombinant Hepatitis B core antigen to produce virus-like particles presenting M2e (M2e-VLPs. We produced the VLPs with and without entrapped nucleic acids and compared their immunogenicity and protective efficacy. Immunization of BALB/c mice with M2e-VLPs containing nucleic acids induced a stronger, Th1-biased antibody response compared to particles lacking nucleic acids. The former also induced a stronger M2e-specific CD4(+ T cell response, as determined by ELISPOT. Mice vaccinated with alum-adjuvanted M2e-VLPs containing the nucleic acid-binding domain were better protected against influenza A virus challenge than mice vaccinated with similar particles lacking this domain, as deduced from the loss in body weight following challenge with X47 (H3N2 or PR/8 virus. Challenge of mice that had been immunized with M2e-VLPs with or without nucleic acids displayed significantly lower mortality, morbidity and lung virus titers than control-immunized groups. We conclude that nucleic acids present in M2e-VLPs correlate with improved immune protection.
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
Surman, S L; Penkert, R R; Jones, B G; Sealy, R E; Hurwitz, J L
Vitamin A and D deficiencies and insufficiencies are prevalent worldwide in developed and developing countries. Vitamin metabolites are functionally intertwined in that they are high-affinity ligands for related receptors of the nuclear receptor superfamily. The effects of vitamin A deficiencies (VAD) on antibody responses to respiratory virus vaccines have already been demonstrated. Of particular concern was the reduction in IgA, a first line of defense against pathogens in the respiratory tract. Here, we describe the individual and combined effects of vitamin A and D deficiencies in mice immunized with an attenuated influenza virus vaccine. Relative to VAD, vitamin D deficiency (VDD) had a limited effect, but double deficiencies for vitamins A and D (VAD+VDD) further reduced antibody responses in the respiratory tract. The administration of supplemental vitamins A and D to VAD+VDD mice at the time of vaccination restored responses in a dose-dependent manner. Results suggest that vitamin supplementation programs may be beneficial in a clinical setting to promote healthy immune responses to respiratory virus vaccines in vitamin-deficient individuals.
Sumathy, K; Ella, Krishna M
The genetic diversity of Chikungunya virus (CHIKV) causing recurring outbreaks in India since 2006 was studied. The 2006 epidemic was caused by a virus strain of the East, Central and South African (ECSA) genotype with 226A in the E1 glycoprotein. The variant strain with E1-A226V mutation caused outbreaks since 2007 in the state of Kerala where Aedes albopictus is the abundant mosquito vector. Molecular epidemiology data since 2007 is scarce from other regions of the country. RT-PCR, sequencing and phylogenetic analyses of CHIKV isolates from the 2009 to 2010 epidemics in the States of Tamil Nadu and Andhra Pradesh placed them in a separate clade within the ECSA lineage. The isolates of the study had 226A in the E1 glycoprotein. The isolates had a novel E1-K211E mutation that was under significant positive selection. E1-211E is highly conserved in the Asian genotype of the virus circulated by Aedes aegypti. Unique mutations in E2 glycoprotein were identified. The two sub-lineages of ECSA genotype circulating in India parallel the abundance of Ae. albopictus and Ae. aegypti. Novel mutations in the envelope glycoproteins suggest adaptive evolution of the virus to local vector abundance. Cross neutralization of the virus isolates from recurring Indian epidemics indicated that no distinct serotypes had evolved. The study has provided insights into the origin, distribution and evolutionary adaptation of the virus to local vector abundance in the region that has reportedly, the highest incidence of CHIKV infection in the world. PMID:22246833
Sumathy, K; Ella, Krishna M
The genetic diversity of Chikungunya virus (CHIKV) causing recurring outbreaks in India since 2006 was studied. The 2006 epidemic was caused by a virus strain of the East, Central and South African (ECSA) genotype with 226A in the E1 glycoprotein. The variant strain with E1-A226V mutation caused outbreaks since 2007 in the state of Kerala where Aedes albopictus is the abundant mosquito vector. Molecular epidemiology data since 2007 is scarce from other regions of the country. RT-PCR, sequencing and phylogenetic analyses of CHIKV isolates from the 2009 to 2010 epidemics in the States of Tamil Nadu and Andhra Pradesh placed them in a separate clade within the ECSA lineage. The isolates of the study had 226A in the E1 glycoprotein. The isolates had a novel E1-K211E mutation that was under significant positive selection. E1-211E is highly conserved in the Asian genotype of the virus circulated by Aedes aegypti. Unique mutations in E2 glycoprotein were identified. The two sub-lineages of ECSA genotype circulating in India parallel the abundance of Ae. albopictus and Ae. aegypti. Novel mutations in the envelope glycoproteins suggest adaptive evolution of the virus to local vector abundance. Cross neutralization of the virus isolates from recurring Indian epidemics indicated that no distinct serotypes had evolved. The study has provided insights into the origin, distribution and evolutionary adaptation of the virus to local vector abundance in the region that has reportedly, the highest incidence of CHIKV infection in the world.
Louis H. Nel
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.
Art is a good place to learn about our multicultural planet, and African masks are prized throughout the world as powerfully expressive artistic images. Unfortunately, multicultural education, especially for young children, can perpetuate stereotypes. Masks taken out of context lose their meaning and the term "African masks" suggests that there is…
Jensen, Hans Grinsted; Sandrey, Ron
This article starts with a profile of African agricultural trade. Using the pre-release version 9.2 of the GTAP database, we then show that the results for tariff elimination on intra-African trade are promising, but these tariff barriers are not as significant as the various trade-related barriers...
Describes the Igbo tradition of "Mbari," a communal creative enterprise that celebrates the world and the life lived in it through art. Contrasts the cooperative, social dimension of pre-colonial African culture with the exclusion and denial of European colonialism, and sees new African literature again celebrating human presence and dignity. (AF)
China helps bring lasting peace and stability to Africa African think tanks expressed a high opinion of China’s role in helping build African peace and security at the first meeting of the China-Africa Think Tanks Forum. The
O'Shea, Thomas; Cryan, Paul M.; Cunningham, Andrew A.; Fooks, Anthony R.; Hayman, David T.S.; Luis, Angela D.; Peel, Alison J.; Plowright, Raina K.; Wood, James L.N.
Bats are sources of high viral diversity and high-profile zoonotic viruses worldwide. Although apparently not pathogenic in their reservoir hosts, some viruses from bats severely affect other mammals, including humans. Examples include severe acute respiratory syndrome coronaviruses, Ebola and Marburg viruses, and Nipah and Hendra viruses. Factors underlying high viral diversity in bats are the subject of speculation. We hypothesize that flight, a factor common to all bats but to no other mammals, provides an intensive selective force for coexistence with viral parasites through a daily cycle that elevates metabolism and body temperature analogous to the febrile response in other mammals. On an evolutionary scale, this host–virus interaction might have resulted in the large diversity of zoonotic viruses in bats, possibly through bat viruses adapting to be more tolerant of the fever response and less virulent to their natural hosts.
Patrícia C C Neves
Full Text Available Yellow Fever vaccine is one of the most efficacious human vaccines ever made. The vaccine (YF 17D virus induces polyvalent immune responses, with a mixed TH1/TH2 CD4(+ cell profile, which results in robust T CD8(+ responses and high titers of neutralizing antibody. In recent years, it has been suggested that early events after yellow fever vaccination are crucial to the development of adequate acquired immunity. We have previously shown that primary immunization of humans and monkeys with YF 17D virus vaccine resulted in the early synthesis of IFN-γ. Herein we have demonstrated, for the first time that early IFN-γ production after yellow fever vaccination is a feature also of murine infection and is much more pronounced in the C57BL/6 strain compared to the BALB/c strain. Likewise, in C57BL/6 strain, we have observed the highest CD8(+ T cells responses as well as higher titers of neutralizing antibodies and total anti-YF IgG. Regardless of this intense IFN-γ response in mice, it was not possible to see higher titers of IgG2a in relation to IgG1 in both mice lineages. However, IgG2a titers were positively correlated to neutralizing antibodies levels, pointing to an important role of IFN-γ in eliciting high quality responses against YF 17D, therefore influencing the immunogenicity of this vaccine.
Juul-Madsen, Helle R.; Norup, Liselotte R.; Jørgensen, Poul Henrik;
. Serum MBL levels also influenced IBV vaccine-induced changes in circulating T-cell populations. Moreover, addition of mannose to an IBV vaccine altered both vaccine-induced changes in circulating T-cell populations and IBV specific vaccine and infection-induced antibody responses in chickens with high...... serum MBL levels. These data demonstrate that MBL is involved in the regulation of the adaptive immune response to IBV....
Hays, Krystal; Aranda, Maria P.
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,…
Ladner, Jason T.; Wiley, Michael R.; Prieto, Karla; Yasuda, Chadwick Y.; Nagle, Elyse; Kasper, Matthew R.; Reyes, Daniel; Vasilakis, Nikolaos; Heang, Vireak; Weaver, Scott C.; Haddow, Andrew; Tesh, Robert B.; Sovann, Ly; Palacios, Gustavo
Zika virus is an emerging human pathogen of great concern due to putative links to microcephaly and Guillain-Barre syndrome. Here, we report the complete genomes, including the 5′ and 3′ untranslated regions, of five Zika virus isolates, one from the Asian lineage and four from the African lineage.
Ladner, Jason T; Wiley, Michael R; Prieto, Karla; Yasuda, Chadwick Y; Nagle, Elyse; Kasper, Matthew R; Reyes, Daniel; Vasilakis, Nikolaos; Heang, Vireak; Weaver, Scott C; Haddow, Andrew; Tesh, Robert B; Sovann, Ly; Palacios, Gustavo
Zika virus is an emerging human pathogen of great concern due to putative links to microcephaly and Guillain-Barre syndrome. Here, we report the complete genomes, including the 5' and 3' untranslated regions, of five Zika virus isolates, one from the Asian lineage and four from the African lineage.
Full Text Available The migration of blacks in North America through slavery became united. The population of blacks past downs a tradition of artist through art to native born citizens. The art tradition involved telling stories to each generation in black families. The black culture elevated by tradition created hope to determine their personal freedom to escape from poverty of enslavement and to establish a way of life through tradition. A way of personal freedoms was through getting a good education that lead to a better foundation and a better way of life. With regard to all historic migrations (forced and voluntary, the African Union defined the African diaspora as "[consisting] of people of African origin living outside the continent, irrespective of their citizenship and nationality and who are willing to contribute to the development of the continent and the building of the African Union." Its constitutive act declares that it shall "invite and encourage the full participation of the African diaspora as an important part of our continent, in the building of the African Union." Keywords: literature concepts, African American abstracts
Reperant, L A; Brown, I H; Haenen, O L; de Jong, M D; Osterhaus, A D M E; Papa, A; Rimstad, E; Valarcher, J-F; Kuiken, T
Companion animals comprise a wide variety of species, including dogs, cats, horses, ferrets, guinea pigs, reptiles, birds and ornamental fish, as well as food production animal species, such as domestic pigs, kept as companion animals. Despite their prominent place in human society, little is known about the role of companion animals as sources of viruses for people and food production animals. Therefore, we reviewed the literature for accounts of infections of companion animals by zoonotic viruses and viruses of food production animals, and prioritized these viruses in terms of human health and economic importance. In total, 138 virus species reportedly capable of infecting companion animals were of concern for human and food production animal health: 59 of these viruses were infectious for human beings, 135 were infectious for food production mammals and birds, and 22 were infectious for food production fishes. Viruses of highest concern for human health included hantaviruses, Tahyna virus, rabies virus, West Nile virus, tick-borne encephalitis virus, Crimean-Congo haemorrhagic fever virus, Aichi virus, European bat lyssavirus, hepatitis E virus, cowpox virus, G5 rotavirus, influenza A virus and lymphocytic choriomeningitis virus. Viruses of highest concern for food production mammals and birds included bluetongue virus, African swine fever virus, foot-and-mouth disease virus, lumpy skin disease virus, Rift Valley fever virus, porcine circovirus, classical swine fever virus, equine herpesvirus 9, peste des petits ruminants virus and equine infectious anaemia virus. Viruses of highest concern for food production fishes included cyprinid herpesvirus 3 (koi herpesvirus), viral haemorrhagic septicaemia virus and infectious pancreatic necrosis virus. Of particular concern as sources of zoonotic or food production animal viruses were domestic carnivores, rodents and food production animals kept as companion animals. The current list of viruses provides an objective
Martin Rowe; Leah Fitzsimmons; Bell, Andrew I.
In 1964, a new herpesvirus, Epstein-Barr virus (EBV), was discovered in cultured tumor cells derived from a Burkitt lymphoma (BL) biopsy taken from an African patient. This was a momentous event that reinvigorated research into viruses as a possible cause of human cancers. Subsequent studies demonstrated that EBV was a potent growth-transforming agent for primary B cells, and that all cases of BL carried characteristic chromosomal translocations resulting in constitutive activation of the c-M...
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
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
Emmanuel, Nikolas G.
peacekeeping operations in the region. It is important to add that the international community has frequently tried to facilitate the deployment of African armed forces with aid and training. From this reality, the following study goes beyond the current literature by focusing on the international factors...... behind African participation in United Nations (UN) peacekeeping operations in Africa. In doing so, this research focuses on US military aid and foreign troop training from 2002 to 2012, and its impact on African deployments into UN peacekeeping missions in Africa. As can be expected, such third...
There is so much alienation, pain and suffering in our today�s world. In this vein, African Christianity, a voice amongst many voices, should seek to be a transformational religion for the whole of life, affecting all facets of human life towards a fuller life of all in Africa. This article sought to highlight and point to some of the major societal challenges in the African context which African Christianity, as a life-affirming religion, should continue to embrace, re-embrace and engag...
Venter, Gert Johannes
The aim of this paper is to consolidate vector competence studies on Culicoides midges (Diptera: Ceratopogonidae) as vectors of bluetongue virus (BTV) done over a period 25 years at the ARC‑Onderstepoort Veterinary Institute in South Africa. In 1944, it was demonstrated for the first time in South Africa that Culicoides midges transmit BTV. In 1991, field‑collected Culicoides imicola were fed on blood containing BTV‑3 or ‑6 and the infection rates were established as being 31% and 24%, respectively. In 1998, Culicoides bolitinos was shown to have a higher infection prevalence and virus titre/midge than C. imicola. This species was then shown to have a higher transmission potential for BTV‑1 over a range of incubation temperatures wider than the one showed by C. imicola. Attenuation of BTV also does not reduce its ability to infect competent Culicoides species. Oral susceptibility studies, involving 29 BTV isolates of various serotypes, indicated differences between various geographic virus isolates and Culicoides populations evaluated. While low recovery rates of European BTV strains from South African Culicoides species suggest co‑adaptation between orbiviruses and vectors in a given locality, co‑adaption was shown not to be essential for virus transmission. Cumulative results since 1991 provide evidence that at least 13 livestock‑associated Culicoides species are susceptible to BTV. Susceptibility results are supported by field isolations from 5 of these species. This implies that multi‑vector potential for the transmission of BTV will complicate the epidemiology of BT. It must be emphasised that neither oral susceptibility nor virus isolation/detection from field‑collected specimens is proof that a species is a confirmed field vector. PMID:26741247
Taylor, Scott D.
Scholars and practitioners once commonly linked 'African culture' to a distinctive 'African capitalism', at odds with genuine capitalism and the demands of modern business. Yet contemporary African business cultures reveal that a capitalist ethos has taken hold within both state and society. The success and visibility of an emergent, and celebrated, class of African big business reveals that business and profit are culturally acceptable. Existing theories of African capitalism are ill-equippe...
Gachara, George; Symekher, Samuel; Otieno, Michael; Magana, Japheth; Opot, Benjamin; Bulimo, Wallace
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.
MacKinnon, Aran S
The South African mining industry relied upon a massive African migrant workforce from the rural areas. Rural transformations in this migrant labor system form an important part of the story of developing capitalism in industrializing South Africa. Yet, recent historical studies on southern African migrant and rural wage labor have paid little attention to life adjustments made by the elderly and those 'burned out' by the mines and forced to leave formal wage employment in the urban areas. The South African segregationist state's rhetoric implied that 'retired' Africans could find economic security in their designated rural reserves. Indeed, legislation sought to prohibit Africans who were not employed from remaining in the 'white' urban areas. By the 1930s, however, the reserves were rapidly deteriorating. Many elderly Africans could not retire and were forced to seek wage labor. This raises significant questions about how retirement came to be defined and experienced by Africans in South Africa during a critical period of dramatic economic decline in the 1930s and 40s, and what the underlying material circumstances of African South Africans were with regard to adaptations to employment and ageing-related life changes. In many cases, elderly Africans were forced to forgo retirement, and find wage labor, usually in the most poorly paid, least sought-after or dangerous fields of employment. This article thus seeks to illuminate critical generational dimensions of the impact of segregation and racism in South Africa prior to the formal articulation of Apartheid. PMID:17939024
MacKinnon, Aran S
The South African mining industry relied upon a massive African migrant workforce from the rural areas. Rural transformations in this migrant labor system form an important part of the story of developing capitalism in industrializing South Africa. Yet, recent historical studies on southern African migrant and rural wage labor have paid little attention to life adjustments made by the elderly and those 'burned out' by the mines and forced to leave formal wage employment in the urban areas. The South African segregationist state's rhetoric implied that 'retired' Africans could find economic security in their designated rural reserves. Indeed, legislation sought to prohibit Africans who were not employed from remaining in the 'white' urban areas. By the 1930s, however, the reserves were rapidly deteriorating. Many elderly Africans could not retire and were forced to seek wage labor. This raises significant questions about how retirement came to be defined and experienced by Africans in South Africa during a critical period of dramatic economic decline in the 1930s and 40s, and what the underlying material circumstances of African South Africans were with regard to adaptations to employment and ageing-related life changes. In many cases, elderly Africans were forced to forgo retirement, and find wage labor, usually in the most poorly paid, least sought-after or dangerous fields of employment. This article thus seeks to illuminate critical generational dimensions of the impact of segregation and racism in South Africa prior to the formal articulation of Apartheid.
Rao, Deepa; Molina, Yamile; Lambert, Nina; Cohn, Susan E.
Purpose In the present study, we validated a culturally adapted stigma scale designed to assess stigma among African Americans living with HIV. Methods We collected data on the scale using an audio computer assisted self-interview (ACASI) format. We validated the scale with a sample of 62 African American participants living with HIV. Results Findings demonstrated that stigma can be measured succinctly and effectively in a 14-item scale with two subscales measuring enacted and internalized stigma. Discussion We identified many advantages to using the scale, which demonstrated good psychometric properties when used with an audio computer assisted self-interview format and with an African American sample. We recommend this scale’s use in both clinical practice and research study of HIV-stigma reduction interventions with African American populations.
Full Text Available Objective: There is ongoing debate about the association between Human Mammary Tumor Virus (HMTV infection and breast cancer. A systematic review (SR published in 2014 revealed that there was a statistically significant association. However, there was suspected duplication of the studies selected in that SR, and it also presented the need for a more detailed subgroup analysis by region. Therefore, the present study repeated the meta-analysis with the addition of relevant papers published before October 2015. Methods: Using the papers selected for the previous SR, a list was made of the references, and the “cited articles” and “similar articles” provided by PubMed. Of these, we only selected case-control studies that used PCR to detect the HMTV gene in tissue. The criterion for duplication was papers that showed identical researcher names or affiliated institutions. Among duplicated papers, the one with the largest number of samples was chosen. The meta-analysis was used to obtain summary odds ratio (SOR and 95% confidence interval (CI. Results: A total of 13 case-control studies were selected. The total number of the case and control groups was 1,878 and 1,204 persons, respectively. The results of the meta-analysis for these 13 papers showed that HMTV infection increased the risk of breast cancer (SOR=8.37, 95% CI: 2.29-23.39; I-squared = 98.4%. Conclusion: In the sub-group analysis, there was statistical significance for North America, the Mediterranean, and Australia. The results of this study support the claim that HMTV infection increases the risk of human breast cancer.
Rothmann, S.; Barkhuizen, N.
The objectives of this study are to assess the psychometric properties of an adapted version of the Maslach Burnout Inventory-General Survey (MBI-GS) for academic staff in South African higher education institutions and to investigate differences between the burnout levels of different demographic groups. A survey design was used, with stratified…
Mwai, Okeyo; Hanotte, Olivier; Kwon, Young-Jun; Cho, Seoae
At least 150 indigenous African cattle breeds have been named, but the majority of African cattle populations remain largely uncharacterized. As cattle breeds and populations in Africa adapted to various local environmental conditions, they acquired unique features. We know now that the history of African cattle was particularly complex and while several of its episodes remain debated, there is no doubt that African cattle population evolved dramatically over time. Today, we find a mosaic of genetically diverse population from the purest Bos taurus to the nearly pure Bos indicus. African cattle are now found all across the continent, with the exception of the Sahara and the river Congo basin. They are found on the rift valley highlands as well as below sea level in the Afar depression. These unique livestock genetic resources are in danger to disappear rapidly following uncontrolled crossbreeding and breed replacements with exotic breeds. Breeding improvement programs of African indigenous livestock remain too few while paradoxically the demand of livestock products is continually increasing. Many African indigenous breeds are endangered now, and their unique adaptive traits may be lost forever. This paper reviews the unique known characteristics of indigenous African cattle populations while describing the opportunities, the necessity and urgency to understand and utilize these resources to respond to the needs of the people of the continent and to the benefit of African farmers. PMID:26104394
Woźniakowski, Grzegorz; Kozak, Edyta; Niemczuk, Krzysztof; Frączyk, Magdalena; Bocian, Łukasz; Kowalczyk, Andrzej; Pejsak, Zygmunt
In Poland, African swine fever (ASF) emerged in February 2014; by August 2015, the virus had been detected in >130 wild boar and in pigs in 3 backyard holdings. We evaluated ASF spread in Poland during these 18 months. Phylogenetic analysis indicated repeated incursions of genetically distinct ASF viruses of genotype II; the number of cases positively correlated wild boar density; and disease spread was very slow. More cases were reported during summer than autumn. The 18-month prevalence of ASF in areas under various animal movement restrictions was 18.6% among wild boar found dead or killed by vehicles and only 0.2% in hunted wild boar. Repeated introductions of the virus into the country, the primary role of wild boar in virus maintenance, and the slow spread of the disease indicate a need for enhanced biosecurity at pig holdings and continuous and intensive surveillance for fast detection of ASF. PMID:27314611
Petersen, Kjell Yngve; Søndergaard, Karin; Kongshaug, Jesper
Adaptive LightingAdaptive lighting is based on a partial automation of the possibilities to adjust the colour tone and brightness levels of light in order to adapt to people’s needs and desires. IT support is key to the technical developments that afford adaptive control systems. The possibilities offered by adaptive lighting control are created by the ways that the system components, the network and data flow can be coordinated through software so that the dynamic variations are controlled i...
... Share Plus on Google Plus African-Americans and Alzheimer's alz.org | IHaveAlz Introduction 10 Warning Signs Brain ... African-Americans are at a higher risk for Alzheimer's disease. Many Americans dismiss the warning signs of ...
Diagne, Cheikh Tidiane; Diallo, Diawo; Faye, Oumar; Ba, Yamar; Gaye, Alioune; Dia, Ibrahima; Faye, Ousmane; Weaver, Scott C.; Sall, Amadou Alpha; Diallo, Mawlouth
Background Zika virus (ZIKV; genus Flavivirus, family Flaviviridae) is an emerging virus of medical importance maintained in a zoonotic cycle between arboreal Aedes spp. mosquitoes and nonhuman primates in African and Asian forests. Serological evidence and virus isolations have demonstrated widespread distribution of the virus in Senegal. Several mosquito species have been found naturally infected by ZIKV but little is known about their vector competence. Methods We assessed the vector compe...
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.
Full Text Available Influenza viruses transcribe and replicate their genomes in the nuclei of infected host cells. The viral ribonucleoprotein (vRNP complex of influenza virus is the essential genetic unit of the virus. The viral proteins play important roles in multiple processes, including virus structural maintenance, mediating nucleocytoplasmic shuttling of the vRNP complex, virus particle assembly, and budding. Nucleocytoplasmic shuttling of viral proteins occurs throughout the entire virus life cycle. This review mainly focuses on matrix protein (M1, nucleoprotein (NP, nonstructural protein (NS1, and nuclear export protein (NEP, summarizing the mechanisms of their nucleocytoplasmic shuttling and the regulation of virus replication through their phosphorylation to further understand the regulation of nucleocytoplasmic shuttling in host adaptation of the viruses.
Holbrook, Jarita C; Medupe, R. Thebe; Current Archaeoastronomy and Ethnoastronomy research in Africa
Astronomy is the science of studying the sky using telescopes and light collectors such as photographic plates or CCD detectors. However, people have always studied the sky and continue to study the sky without the aid of instruments this is the realm of cultural astronomy. This is the first scholarly collection of articles focused on the cultural astronomy of Africans. It weaves together astronomy, anthropology, and Africa. The volume includes African myths and legends about the sky, alignments to celestial bodies found at archaeological sites and at places of worship, rock art with celestial imagery, and scientific thinking revealed in local astronomy traditions including ethnomathematics and the creation of calendars. Authors include astronomers Kim Malville, Johnson Urama, and Thebe Medupe; archaeologist Felix Chami, and geographer Michael Bonine, and many new authors. As an emerging subfield of cultural astronomy, African cultural astronomy researchers are focused on training students specifically for do...
Andel, van T.R.
African slaves brought plant knowledge to the New World, sometimes applying it to related plants they found there and sometimes bringing Old World plants with them. By tracing the linguistic parallels between names for plants in African languages and in communities descended from African slaves, pie
Maseko, Pam; Vale, Peter
In this interview, African Language expert Pam Maseko speaks of her own background and her first encounter with culture outside of her mother tongue, isiXhosa. A statistical breakdown of South African languages is provided as background. She discusses Western (originally missionary) codification of African languages and suggests that this approach…
Coughlin, Steven S; Yoo, Wonsuk; Whitehead, Mary S; Smith, Selina A
Advances have occurred in breast cancer survivorship but, for many African-American women, challenges and gaps in relevant information remain. This article identifies opportunities to address disparities in breast cancer survival and quality of life, and thereby to increase breast cancer survivorship among African-American women. For breast cancer survivors, common side effects, lasting for long periods after cancer treatment, include fatigue, loss of strength, difficulty sleeping, and sexual dysfunction. For addressing physical and mental health concerns, a variety of interventions have been evaluated, including exercise and weight training, dietary interventions, yoga and mindfulness-based stress reduction, and support groups or group therapy. Obesity has been associated with breast cancer recurrence and poorer survival. Relative to white survivors, African-American breast cancer survivors are more likely to be obese and less likely to engage in physical activity, although exercise improves overall quality of life and cancer-related fatigue. Considerable information exists about the effectiveness of such interventions for alleviating distress and improving quality of life among breast cancer survivors, but few studies have focused specifically on African-American women with a breast cancer diagnosis. Studies have identified a number of personal factors that are associated with resilience, increased quality of life, and positive adaptation to a breast cancer diagnosis. There is a need for a better understanding of breast cancer survivorship among African-American women. Additional evaluations of interventions for improving the quality of life and survival of African-American breast cancer survivors are desirable. PMID:26303657
赵玉娇; 潘玥; 陈俊英; 杨丽娟; 岳耀斐; 施海晶; 马绍辉; 孙强明
目的 筛选Ⅰ型登革病毒(Dengue virus,DV)中国株D06063人胚肺二倍体细胞KMB17的适应株,经噬斑纯化后,分析其生物学特性.方法 将Ⅰ型DV中国株D06063在C6/36细胞上进行扩增,采用微量滴定法测定病毒的感染性滴度;RT-PCR法鉴定DV型别；病毒连续以4.0 MOI的量感染KMB17细胞,传代至病毒完全适应在细胞内扩增,再连续传10代,筛选出KMB17细胞适应株,并进行3轮噬斑纯化；免疫荧光法检测纯化病毒,电镜观察病毒颗粒的形态.结果 在C6/36细胞上扩增的Ⅰ型DV D06063株的滴度为6.0 lg CCID5o/ml,经RT-PCR可扩增出511 bp的DV特异基因和482 bp的Ⅰ型DV型特异性基因；病毒感染KMB17细胞后,可产生明显的细胞病变,至第10代,病毒的感染性滴度达峰值,为6.75 lg CCID50/ml;纯化的病毒经免疫荧光检测呈阳性,电镜观察显示病毒形态正常.结论 成功筛选出传代稳定性好、病毒扩增量高的Ⅰ型DVKMB17细胞适应株,纯化的病毒株保持了原始毒株的基本生物学特性.%Objective To screen the adaptive strain of Dengue-Ⅰ virus D06063 strain (China strain) in human diploid KMB17 cells, subject to plaque purification and analyze its biological characteristics. Methods Dengue- I virus D06063 strain was propagated in C6/36 cells, determined for infectious titer by microtitration, and identified for type by RT-PCR, then subcultured in KMB17 cells at a MOI of 4. 0 till the virus was completely adapted to propagation in cell, and further subcultured for 10 passages. The adapted strain was screened and subjected to three rounds of plaque purification. The purified strain was analyzed by IFA and observed for morphology of virus particles by electron microscopy. Results The Dengue- I virus D06063 strain propagated in C6/36 cells reached a titer of 6. 0 lgCCID50/ml, from which the Dengue virus (DV) specific gene at a length of 511 bp, and DV type Ⅰ specific gene at a length of 482 bp were amplified by
Vazeille, Marie; Zouache, Karima; Vega-Rúa, Anubis; Thiberge, Jean-Michel; Caro, Valérie; Yébakima, André; Mousson, Laurence; Piorkowski, Géraldine; Dauga, Catherine; Vaney, Marie-Christine; Manni, Mosè; Gasperi, Giuliano; de Lamballerie, Xavier; Failloux, Anna-Bella
Most arthropod-borne viruses (arboviruses), perpetuated by alternation between a vertebrate host and an insect vector, are likely to emerge through minor genetic changes enabling the virus to adapt to new hosts. In the past decade, chikungunya virus (CHIKV; Alphavirus, Togaviridae) has emerged on La Réunion Island following the selection of a unique substitution in the CHIKV E1 envelope glycoprotein (E1-A226V) of an East-Central-South African (ECSA) genotype conferring a higher transmission rate by the mosquito Aedes albopictus. Assumed to have occurred independently on at least four separate occasions, this evolutionary convergence was suspected to be responsible for CHIKV worldwide expansion. However, assumptions on CHIKV emergence were mainly based on viral genetic changes and the role of the mosquito population quasispecies remained unexplored. Here we show that the nature of the vector population is pivotal in selecting the epidemic CHIKV. We demonstrate using microsatellites mosquito genotyping that Ae. albopictus populations are genetically differentiated, contributing to explain their differential ability to select the E1-226V mutation. Aedes albopictus, newly introduced in Congo coinciding with the first CHIKV outbreak, was not able to select the substitution E1-A226V nor to preferentially transmit a CHIKV clone harboring the E1-226V as did Ae. albopictus from La Réunion. PMID:27383735
Susanne E Biesold
Full Text Available 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.
Zika is a virus that is spread mostly by mosquitoes. A pregnant mother can pass it to ... through blood transfusions. There have been outbreaks of Zika virus in the United States, Africa, Southeast Asia, ...
Chikungunya virus infection; Chikungunya ... Where Chikungunya is found Before 2013, the virus was found in Africa, Asia, Europe, and the Indian and Pacific oceans. In late 2013, outbreaks occurred for the first time in the ...
... Gaines, PhD, MPH, MA, CHES Differentiating Chikungunya From Dengue: A Clinical Challenge For Travelers CDC Travelers' Health Chikungunya Virus Home Prevention Transmission Symptoms & Treatment Geographic Distribution Chikungunya virus in ...
Jennifer Browdy de Hernandez; Pauline Dongala; Omotayo; Jolaosho; Anne Serafin
AFRICAN Women Writing Resistance is the first transnational anthology to focus on women's strategies of resistance to the challenges they face in Africa today.The anthology brings together personal narratives,testimony,interviews,short stories,poetry,performance scripts,folktales and lyrics.
Jennifer; Browdy; de; Hernandez; Pauline; Dongala; Omotayo; Jolaosho; Anne; Serafin
An Anthology of Contemporary Voices AFRICAN Women Writing Resistance is the first transnational anthology to focus on women’s strategies of resistance to the challenges they face in Africa today.The anthology brings together personal narratives,testimony,interviews, short stories,po-
Chinese President Hu Jintao has just embarked on his state visits to eight African countries that will take him to both the northern and southern tips of the continent. This is his first trip abroad this year, and also his third visit to Africa
Nordby, Johannes Riber; Jacobsen, Katja
For the past decade security in East Africa has gained focus internationally. However there is a growing ambition among African states to handle such issues by themselves, sometimes through regional institutions. This has been supported by many Western states but potential risks are often forgotten....
Johansen, Jakob Aaquist; Thybo, Søren
The incident of spotted fever imported to Denmark is unknown. We present a classic case of African Tick Bite Fever (ATBF) to highlight a disease, which frequently infects wildlife enthusiasts and hunters on vacation in South Africa. ATBF has a good prognosis and is easily treated with doxycyclin...
Hahonou, Eric Komlavi; Pelckmans, Lotte
In the context of liberalization of West African political regimes, the upsurge of audacious political entrepreneurs who want to end chattel slavery in their nation-state, resulted in the legal criminalisation of slavery in both Mauritania (2007) and Niger (2003) and in a proposal to revise the...... cultures (or ‘mentalities’) go hand in hand....
... Program Grants Other Grants Planning and Evaluation Grantee Best Practices Black/African American Asthma Cancer Chronic Liver Disease ... 13 to 17 years who ever received the human papillomavirus (HPV) vaccination, 2014 - Males # doses ... 240-453-2882 Office of Minority Health Resource Center Toll Free: 1-800-444-6472 / Fax: ...
TAN Ying; ZHANG Pengtao
The computer virus is considered one of the most horrifying threats to the security of computer systems worldwide.The rapid development of evasion techniques used in virus causes the signature based computer virus detection techniques to be ineffective.Many novel computer virus detection approaches have been proposed in the past to cope with the ineffectiveness,mainly classified into three categories:static,dynamic and heuristics techniques.As the natural similarities between the biological immune system (BIS),computer security system (CSS),and the artificial immune system (AIS) were all developed as a new prototype in the community of anti-virus research.The immune mechanisms in the BIS provide the opportunities to construct computer virus detection models that are robust and adaptive with the ability to detect unseen viruses.In this paper,a variety of classic computer virus detection approaches were introduced and reviewed based on the background knowledge of the computer virus history.Next,a variety of immune based computer virus detection approaches were also discussed in detail.Promising experimental results suggest that the immune based computer virus detection approaches were able to detect new variants and unseen viruses at lower false positive rates,which have paved a new way for the anti-virus research.
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.
Full Text Available The article builds on the existing dispute between African and African American women writers on the competence of writing about female genital mutilation (FGM, and tries to determine the existence and nature of the differences between the writings of these two groups. The author uses comparative analysis of two popular African and African American novels, comparing their ways of describing FGM, its causes and consequences, the level ob objectivity and the style of the narrations.This is followed by a discussion on the reasons for such differences, incorporating a larger circle of both African and African American women authors, at the same time analysing the deviance within the two groups. While the differences between African American writers are not that great, as they mostly fail to present the issue from different points of view, which is often the result of their lack of direct knowledge of the topic, African authors' writing is in itself discovered to be ambivalent and not at all invariable. The reasons for such ambivalence are then discussed in greater context, focusing on the effect of the authors' personal contact with circumcision as well as their knowledge and acceptance of Western values. The author concludes by establishing the African ambivalent attitude towards FGM, which includes different aspects of the issue, as the most significant difference between their and African American writers' description of this practice.
Phylogenetic analysis of three genes of Penguinpox virus corresponding to Vaccinia virus G8R (VLTF-1, A3L (P4b and H3L reveals that it is most closely related to Turkeypox virus, Ostrichpox virus and Pigeonpox virus
Full Text Available Abstract Phylogenetic analysis of three genes of Penguinpox virus, a novel Avipoxvirus isolated from African penguins, reveals its relationship to other poxviruses. The genes corresponding to Vaccinia virus G8R (VLTF-1, A3L (P4b and H3L were sequenced and phylogenetic trees (Neighbour-Joining and UPGMA constructed from MUSCLE nucleotide and amino acid alignments of the equivalent sequences from several different poxviruses. Based on this analysis, PEPV was confirmed to belong to the genus Avipoxvirus, specifically, clade A, subclade A2 and to be most closely related to Turkeypox virus (TKPV, Ostrichpox virus (OSPVand Pigeonpox virus (PGPV.
Petersen, Kjell Yngve; Søndergaard, Karin; Kongshaug, Jesper
Adaptive Lighting Adaptive lighting is based on a partial automation of the possibilities to adjust the colour tone and brightness levels of light in order to adapt to people’s needs and desires. IT support is key to the technical developments that afford adaptive control systems. The possibilities...... offered by adaptive lighting control are created by the ways that the system components, the network and data flow can be coordinated through software so that the dynamic variations are controlled in ways that meaningfully adapt according to people’s situations and design intentions. This book discusses...... distributed differently into an architectural body. We also examine what might occur when light is dynamic and able to change colour, intensity and direction, and when it is adaptive and can be brought into interaction with its surroundings. In short, what happens to an architectural space when artificial...
Denton, Fatima; Anderson, Simon; Ayers, Jessica
Across Africa, programmes such as the Climate Change Adaptation in Africa initiative are investigating what it means for countries and communities to effectively adapt to climate change, and how this can be achieved in practice. But research results are not always recognised by policymakers or the global research community — in part because they are not visible within the traditional hallmark of scientific scholarship and credibility, peer-reviewed literature. Greater efforts are required to encourage African scientists to engage in the peer-review process and give their research the credibility it needs to convince decision makers that robust scientific findings support the solutions offered. At the same time, decision makers themselves must find ways of assessing and making use of robust research outside the peer-review arena.
赵玉娇; 潘玥; 阎玲梅; 岳耀斐; 杨丽娟; 孙强明
Objective: To select the adaptive strain of Dengue- II virus D01090 strain in KMB17 cells, which lay the foundation of the exploration of dengue vaccine using human cells as host. Methods; After extraction of dengue-II D01090 strain genome and identification of the serotype of dengue virus through RT-PCR, the virus was replicated an detected for the titer;The Dengue-II D01090 strain was subcultured in KMB17 cells with 4.0 MOI till the virus completely adapted to multiply in cells, then continued subculturing in KMB17 cells for 10 passages. The adapted strain was screened out, Virus culture fluid was purified by sucrose gradient centrifugation and ultracentrifugation, KMB17 cells was ultrathinsected and observed the pathology under transmission electron microscope after infected with virus; Adapted strain was purified through plaque assay, and the antigenicity was detected by IFA. Results: After dengue- II virus D01090 strain RNA was extracted as templete, a typical 511bp gene segment of dengue virus and a specific 119bp gene segment of dengue- II virus were amplified by RT-PCR. After replication in C6/36 cells, the virus titer could reach 4. 5 CCID50/ml, The CPE of KMB17 cells was appeared earlier after continuous subculture, their titer increased with the increasing passages and get the highest 5.0 CCID50/ml on passage 10. KMB17 cells was ultrathinsected and observed the pathology under transmission electron microscope after 6 days infected with virus and CPE get + + + ,the new packaging virus particles were observed in the endoplasmic reticulum, many small fragment were generated around the cell, with the virus drifting out of the cell. Purified virus strain was screened through three cycles of plaque purification, while antigenicity of purified strain was positive detecting by IFA. Conclusion: Dengue-II virus DO 1090 ( China) adapted strain was screened out which could stably proliferated in KMB17 cells and keep a high virulence, also maintained good
Full Text Available The Western world has always viewed the African continent as plagued by corruption; dictatorship; military coups; rebellious leaders; greediness; misuse of power; and incompetent, politically unstable leaders - in effect, suspicious leaders who undermine their own democracies. This paper analyzes African leadership and its impact by concentrating on three historical eras, namely; the African Religious era; the Christian era, and the era of Globalization. These affected African leadership. In addition, many brilliant minds left the continent in search of greener pastures. A review of these three eras will help us understand how leadership shifted from African values into Western concepts. The role of missionaries lead African people to live with both an African and a Western concept of life. In spite of the above problems, our past leaders did their best in addressing the difficulties they faced during the three eras. African concepts of leadership were often regarded as barbaric and uncultured. Structures were evaluated by Western standards. Due to globalisation, African leaders, through programmes like NEPAD, are going back to basics, drawing on African concepts of unity among its leadership. Effectiveness or life-giving leadership is emerging and empowering villagers/communities in the continent. This type of leadership is innovative and has brought new hope for the continent.
Arndt, Channing; Strzepek, Kenneth; Tarp, Finn;
Mozambique, like many African countries, is already highly susceptible to climate variability and extreme weather events. Climate change threatens to heighten this vulnerability. In order to evaluate potential impacts and adaptation options for Mozambique, we develop an integrated modeling...... framework that translates atmospheric changes from general circulation model projections into biophysical outcomes via detailed hydrologic, crop, hydropower and infrastructure models. These sector models simulate a historical baseline and four extreme climate change scenarios. Sector results are then passed...... down to a dynamic computable general equilibrium model, which is used to estimate economy-wide impacts on national welfare, as well as the total cost of damages caused by climate change. Potential damages without changes in policy are significant; our discounted estimates range from US2.3 to US2.3toUS7...
Lisowski, F P; Albrecht, G H
Analysis of measurements from the tali of 21 individual fossil primates from Africa shows that the specimens fall into five clearly defined groups. Accordingly, these specimens have been included as groups along with extant species in a subsequent canonical analysis thus allowing the fossils to play their part in the determination of the canonical separations. The results of this procedure show that the five fossil groups lie in a part of the canonical space not occupied by any extant African primate. Their positions are between the envelope of Asiatic apes (Hylobates and Pongo) and the envelope of African forms near the edge which contains Pan and Papio. One fossil group is so similar to Hylobates that its talus may have functioned in locomotion in a parallel manner. Others lie near to Pongo in directions proceeding towards Pan and Papio and it is possible that this similarity may indicate remnants of morphological adaptation for climbing in these fossils. At the same time, however, individual specimens are closer to one or another of the extant groups and this considerable spread suggests that the locomotor adaptations as evidenced by talar morphology, of the primate fauna in Africa, may have been very different from those of the present day. This would not the inconsistent with the different habitats, floras and non-primate faunas that may have characterized the East African scene at these earlier times. Particular fossils from Olduvai and Kromdraai that are supposed to be australopithecine and therefore bipeds, are confirmed (Oxnard, '72; Lisowski et al., '74) as being totally different from man in their talar morphology and essentially rather similar to the majority of the other fossil tali examined. PMID:961834
Holt, Cheryl L; Schulz, Emily; Williams, Beverly; Clark, Eddie M; Wang, Min Qi; Southward, Penny L
African American faith communities are an important source of social capital. The present study adapted a theory-based social capital instrument to result in religious (e.g., from organized worship) and spiritual (e.g., from relationship with higher power) capital measures. Data from a national sample of 803 African Americans suggest the instruments have high internal reliability and are distinct from general religiosity. Measurement models confirmed factor structures. Religious capital was positively associated with self-rated health status. Religious and spiritual capital were negatively associated with depressive symptoms, but these associations largely became nonsignificant in multivariate models that controlled for demographic characteristics. An exception is for spiritual capital in the form of community participation, which retained a negative association with depressive symptoms. These instruments may have applied value for health promotion research and practice in African American communities.
Petersen, Kjell Yngve; Søndergaard, Karin; Kongshaug, Jesper
Adaptive Lighting Adaptive lighting is based on a partial automation of the possibilities to adjust the colour tone and brightness levels of light in order to adapt to people’s needs and desires. IT support is key to the technical developments that afford adaptive control systems. The possibilities...... offered by adaptive lighting control are created by the ways that the system components, the network and data flow can be coordinated through software so that the dynamic variations are controlled in ways that meaningfully adapt according to people’s situations and design intentions. This book discusses...... the investigations of lighting scenarios carried out in two test installations: White Cube and White Box. The test installations are discussed as large-scale experiential instruments. In these test installations we examine what could potentially occur when light using LED technology is integrated and...
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
The development of Africa is vital to the world’s sustainable development.However,African countries still face key challenges in achieving the meaningful expansion of their economies.At the High-Level Symposium on China-Africa Investment Cooperation in Xiamen,southeast China’s Fujian Province,held from September 8 to 10,Chen Deming,Minister of Commerce of China,elaborates on these challenges and sees
Provides information on various adaptive technology resources available to people with disabilities. (Contains 19 references, an annotated list of 129 websites, and 12 additional print resources.) (JOW)
National Aeronautics and Space Administration — Advanced Diagnostics and Prognostics Testbed (ADAPT) Project Lead: Scott Poll Subject Fault diagnosis in electrical power systems Description The Advanced...
Ramírez Rozzi, Fernando V; Sardi, Marina L
Although dissimilarities in cranial and post-cranial morphology among African pygmies groups have been recognized, comparative studies on skull morphology usually pull all pygmies together assuming that morphological characters are similar among them and different with respect to other populations. The main aim of this study is to compare cranial morphology between African pygmies and non-pygmies populations from Equatorial Africa derived from both the Eastern and the Western regions in order to test if the greatest morphological difference is obtained in the comparison between pygmies and non-pygmies. Thirty three-dimensional (3D) landmarks registered with Microscribe in four cranial samples (Western and Eastern pygmies and non-pygmies) were obtained. Multivariate analysis (generalized Procrustes analysis, Mahalanobis distances, multivariate regression) and complementary dimensions of size were evaluated with ANOVA and post hoc LSD. Results suggest that important cranial shape differentiation does occur between pygmies and non-pygmies but also between Eastern and Western populations and that size changes and allometries do not affect similarly Eastern and Western pygmies. Therefore, our findings raise serious doubt about the fact to consider African pygmies as a homogenous group in studies on skull morphology. Differences in cranial morphology among pygmies would suggest differentiation after divergence. Although not directly related to skull differentiation, the diversity among pygmies would probably suggest that the process responsible for reduced stature occurred after the split of the ancestors of modern Eastern and Western pygmies.
Fernando V Ramírez Rozzi
Full Text Available Although dissimilarities in cranial and post-cranial morphology among African pygmies groups have been recognized, comparative studies on skull morphology usually pull all pygmies together assuming that morphological characters are similar among them and different with respect to other populations. The main aim of this study is to compare cranial morphology between African pygmies and non-pygmies populations from Equatorial Africa derived from both the Eastern and the Western regions in order to test if the greatest morphological difference is obtained in the comparison between pygmies and non-pygmies. Thirty three-dimensional (3D landmarks registered with Microscribe in four cranial samples (Western and Eastern pygmies and non-pygmies were obtained. Multivariate analysis (generalized Procrustes analysis, Mahalanobis distances, multivariate regression and complementary dimensions of size were evaluated with ANOVA and post hoc LSD. Results suggest that important cranial shape differentiation does occur between pygmies and non-pygmies but also between Eastern and Western populations and that size changes and allometries do not affect similarly Eastern and Western pygmies. Therefore, our findings raise serious doubt about the fact to consider African pygmies as a homogenous group in studies on skull morphology. Differences in cranial morphology among pygmies would suggest differentiation after divergence. Although not directly related to skull differentiation, the diversity among pygmies would probably suggest that the process responsible for reduced stature occurred after the split of the ancestors of modern Eastern and Western pygmies.
Carrillo, L.A.; Nkolo, M. [German Agency for Technical Cooperation GTZ, Delegation Regionale des Eaux et Forets, Bertoua (Cameroon)
In July 2006, the African Non-Petroleum Producers Association was formed in Senegal, Africa to develop alternative energy sources. It involved 13 of Africa's poorest nations, who joined forces to become global suppliers of biofuels, and some have set mandatory mixing of ethanol into gasoline. Although several biofuel production projects have been launched in western Africa, many of the new projects and plantations have not yet reached maturity due to the time lag between plantation and full-scale production, which is about 6 years. Major projects that could be producing significant quantities of biofuels in the next few years are not yet reflected in production statistics. Although ethanol is not yet being produced in large quantities in Africa, short-term opportunities exist. Countries in the South African Development Community are using molasses from the sugar can industry to produce ethanol. Biodiesel is also not currently produced on a significant scale in western Africa, but several other countries are gaining experience with cotton and palm oil resources, and Jatropha. Biomass residue also represents a large potential for all African countries involved in timber production. Unlike biodiesel production, land use conflicts are not an issue with biomass residue production.
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.
White, Martyn K; Wollebo, Hassen S; David Beckham, J; Tyler, Kenneth L; Khalili, Kamel
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. Ann Neurol 2016;80:479-489. PMID:27464346
White, Martyn K; Wollebo, Hassen S; David Beckham, J; Tyler, Kenneth L; Khalili, Kamel
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. Ann Neurol 2016;80:479-489.
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
Khadiagala, Gilbert M.
Since the 1960s, African states have embraced regional integration as a vital mechanism for political cooperation and for pooling resources to overcome problems of small and fragmented economies. In building meaningful institutions for regionalism, however, Africans have faced the challenges of reconciling the diversities of culture, geography, and politics. As a result, African regional institutions are characterized by multiple and competing mandates and weak institutionalization. This stud...
Chen, Jianzhu; Chen, Steve C.-Y.; Stern, Patrick; Scott, Benjamin B; Lois, Carlos
The natural reservoirs of influenza viruses are aquatic birds. After adaptation, avian viruses can acquire the ability to infect humans and cause severe disease. Because domestic poultry serves as a key link between the natural reservoir of influenza viruses and epidemics and pandemics in human populations, an effective measure to control influenza would be to eliminate or reduce influenza virus infection in domestic poultry. The development and distribution of influenza-resistant poultry rep...
Massung, R F; Loparev, V N; Knight, J C; Totmenin, A V; Chizhikov, V E; Parsons, J M; Safronov, P F; Gutorov, V V; Shchelkunov, S N; Esposito, J J
Genome DNA terminal region sequences were determined for a Brazilian alastrim variola minor virus strain Garcia-1966 that was associated with an 0.8% case-fatality rate and African smallpox strains Congo-1970 and Somalia-1977 associated with variola major (9.6%) and minor (0.4%) mortality rates, respectively. A base sequence identity of > or = 98.8% was determined after aligning 30 kb of the left- or right-end region sequences with cognate sequences previously determined for Asian variola major strains India-1967 (31% death rate) and Bangladesh-1975 (18.5% death rate). The deduced amino acid sequences of putative proteins of > or = 65 amino acids also showed relatively high identity, although the Asian and African viruses were clearly more related to each other than to alastrim virus. Alastrim virus contained only 10 of 70 proteins that were 100% identical to homologs in Asian strains, and 7 alastrim-specific proteins were noted. PMID:8661439
... Pressure High Blood Pressure Tools & Resources Stroke More African-Americans and Heart Disease, Stroke Updated:Apr 18, ... of getting those diseases are even higher for African-Americans. The good news is, African-Americans can ...
To the editor.The emerging African Ebola virus infection in 2014 is the global concernl I].To manage this deadly infection,there arestill no effective drugs and vaccines.Searching for new drug is the urgent requirement for successful control of the disease.Based on the new finding,it is noted that Ebola virus VP40
Computer viruses are small software programs that are designed to spread from one computerto another and to interfere with computer operation.A virus might delete data on your computer,use your e-mail program to spread itself to othercomputers,or even erase everything on your hard disk.Viruses are most easily spread by attach-ments in e-mail messages or instant messaging messages.That is why it is essential that you never
Full Text Available A number of viruses have evolved antiapoptotic mechanisms to promote infected-cell survival, either to ensure efficient productive viral replication or to promote long-term survival of virus-infected cells. Recent studies identified critical African swine fever virus genes involved in the complex regulation of ASFV-host interactions. Here we review the present knowledge of the recently identified ASFV genes with special attention to those which affect viral virulence, host range, and pathogenesis by regulating viral-induced apoptotic mechanisms.
Shanley, John D.
An enzyme-linked immunosorbent assay for immunoglobulin G antibody to encephalomyocarditis virus was developed. This assay was comparable to antibody assay by neutralization. Its adaptability should be useful for laboratory and epidemiological studies of infections due to encephalomyocarditis virus.
Diallo, Diawo; Sall, Amadou A; Diagne, Cheikh T.; Faye, Oumar; Faye, Ousmane; Ba, Yamar; Hanley, Kathryn A.; Buenemann, Michaela; Weaver, Scott C.; Diallo, Mawlouth
Background Zika virus (ZIKV; genus Flavivirus, family Flaviviridae) is maintained in a zoonotic cycle between arboreal Aedes spp. mosquitoes and nonhuman primates in African and Asian forests. Spillover into humans has been documented in both regions and the virus is currently responsible for a large outbreak in French Polynesia. ZIKV amplifications are frequent in southeastern Senegal but little is known about their seasonal and spatial dynamics. The aim of this paper is to describe the spat...
Mitchell, John P; Huang, Lynn L; Rosberger, Daniel F
As Acquired Immunodeficiency Disease (AIDS) turns thirty-years old, much progress has been made. 56,000 new cases of the Human Immunodeficiency Virus (HIV) infection are expected in Americans this year. At least half or more will be in African Americans. Reports of the association between syphilis and HIV infection are well documented. We present a case of bilateral optic neuritis and panuveitis as the initial presentation in a previously undiagnosed patient with human immunodeficiency virus (HIV) and syphilis. PMID:27269502
Mate, S.E.; Kugelman, J.R.; Nyenswah, T.G.; Ladner, J. T.; Wiley, M.R.; Cordier-Lassalle, T.; Christie, A; Schroth, G. P.; Gross, S.M.; Davies-Wayne, G.J.; Shinde, S.A.; R. Murugan; Sieh, S.B.; Badio, M.; Fakoli, L.
A suspected case of sexual transmission from a male survivor of Ebola virus disease (EVD) to his female partner (the patient in this report) occurred in Liberia in March 2015. Ebola virus (EBOV) genomes assembled from blood samples from the patient and a semen sample from the survivor were consistent with direct transmission. The genomes shared three substitutions that were absent from all other Western African EBOV sequences and that were distinct from the last documented transmission chain ...
Climate change impact assessments on agriculture are subject to large uncertainties, as demonstrated in the present review of recent studies for Africa. There are multiple reasons for differences in projections, including uncertainties in greenhouse gas emissions and patterns of climate change; assumptions on future management, aggregation, and spatial extent; and methodological differences. Still, all projections agree that climate change poses a significant risk to African agriculture. Most projections also see the possibility of increasing agricultural production under climate change, especially if suitable adaptation measures are assumed. Climate change is not the only projected pressure on African agriculture, which struggles to meet demand today and may need to feed an additional one billion individuals by 2050. Development strategies are urgently needed, but they will need to consider future climate change and its inherent uncertainties. Science needs to show how existing synergies between climate change adaptation and development can be exploited.
Littlejohn, Margaret; Locarnini, Stephen; Yuen, Lilly
Members of the family Hepadnaviridae fall into two subgroups: mammalian and avian. The detection of endogenous avian hepadnavirus DNA integrated into the genomes of zebra finches has revealed a deep evolutionary origin of hepadnaviruses that was not previously recognized, dating back at least 40 million and possibly >80 million years ago. The nonprimate mammalian members of the Hepadnaviridae include the woodchuck hepatitis virus (WHV), the ground squirrel hepatitis virus, and arctic squirrel hepatitis virus, as well as a number of members of the recently described bat hepatitis virus. The identification of hepatitis B viruses (HBVs) in higher primates, such as chimpanzee, gorilla, orangutan, and gibbons that cluster with the human HBV, as well as a number of recombinant forms between humans and primates, further implies a more complex origin of this virus. We discuss the current theories of the origin and evolution of HBV and propose a model that includes cross-species transmissions and subsequent recombination events on a genetic backbone of genotype C HBV infection. The hepatitis delta virus (HDV) is a defective RNA virus requiring the presence of the HBV for the completion of its life cycle. The origins of this virus remain unknown, although some recent studies have suggested an ancient African radiation. The age of the association between HDV and HBV is also unknown. PMID:26729756
Opoku-Mensah, Paul Yaw
This paper, a work-in-progress, makes a contribution to the discussions on the appropriate modalities for incorporating the African diaspora in the African integration project. It argues that the most appropriate entry points for incorporating the African diaspora into the integration project...... might not, necessarily, be in the formal political structures, although this is important. To the contrary, the most effective and sustainable might be within civil society---that is the links between the peoples and organizations of Africa and the diaspora. Using the case of the African academy-- as an...... institution of civil society--- the paper outlines a conceptual framework for incorporating the diaspora into the African integration project....
Blackman, Elizabeth; Campbell, Jasmine; Bowen, Carlene; Delmoor, Ernestine; Jean-Louis, Gilda; Noumbissi, Raphiatou; O'Garro, Yvonne; Richards-Waritay, Oni; Straughter, Stanley; Tolbert, Vera; Wilson, Barbara; Ragin, Camille
This is a brief summary of the 4(th) International Meeting of the African-Caribbean Cancer Consortium (AC3), organized and sponsored by Fox Chase Cancer Center (FCCC), and held on July 21-22, 2012 at the Lincoln University Graduate Center, Lincoln Plaza, Philadelphia, Pennsylvania. AC3 investigators gathered in Philadelphia, PA to present the results of our ongoing collaborative research efforts throughout the African Diaspora. The general theme addressed cancer health disparities and presentations represented all cancer types. However, there was particular emphasis on women's cancers, related to human papillomavirus (HPV) and human immunodeficiency virus (HIV) infections. PMID:26422007
African Conservation Tillage Network (ACT)
Metadata only record Maintained by the African Conservation Tillage Network (ACT), this website provides information on Conservation Agriculture in an African context and gathered by stakeholders (NGOs) native to the continent. Resources on projects, practices, reports, and training courses are provided.
Vammen, Ida Marie; Trans, Lars Ove
Since the early 1990s, an increasing number of African migrants have come to Denmark, where they have formed a large number of migrant associations. This chapter presents selected findings from a comprehensive survey of African diaspora associations in Denmark and focuses specifically on their...
Quail have emerged as a potential intermediate host in the spread of avian influenza A viruses in poultry in Hong Kong. To better understand this possible role, we tested the replication and transmission in quail of influenza A viruses of all 15 HA subtypes. Quail supported the replication of at least 14 subtypes. Influenza A viruses replicated predominantly in the respiratory tract. Transmission experiments suggested that perpetuation of avian influenza viruses in quail requires adaptation. Swine influenza viruses were isolated from the respiratory tract of quail at low levels. There was no evidence of human influenza A or B virus replication. Interestingly, a human-avian recombinant containing the surface glycoprotein genes of a quail virus and the internal genes of a human virus replicated and transmitted readily in quail; therefore, quail could function as amplifiers of influenza virus reassortants that have the potential to infect humans and/or other mammalian species
China’s investment is fueling African growth SINCE 2000,driven by the Forum on China-Africa Cooperation,China’s foreign direct investment(FDI) in Africa has been growing rapidly.In the face of the global financial crisis,which led to global FDI flows falling,China’s investment in Africa has been on a steady, upbeat rise without any interruption.In 2009,China’s direct investment in Africa reached $1.44 billion,of which nonfinancial direct investment soared by 55.4 percent from the previous year.Africa
Jorem, Kaja Tvedten; Jeppesen, Søren; Hansen, Michael W.
In light of recent enthusiasm over the African private sector, this paper reviews the existing empirical literature on successful African enterprises and proposes an analytical framework for understanding African firm success. Overall, it is argued that we need to develop an understanding...... of African firm strategy and performance that takes into account the specificities of the African business environment and African firm capabilities. The paper starts by juxtaposing the widespread pessimistic view of African business with more recent, optimistic studies on African firms’ performance....... The latter suggests that profound improvements in African business performance are indeed under way: with the private sector playing a more important role as an engine of growth, with the rise of a capable African entrepreneurial class, and with the emergence of dynamic and competitive African enterprises...
If you work with a computer,it is certain that you can not avoid dealing, with at least one computer virus.But how much do you know about it? Well,actually,a computer virus is not a biological' one as causes illnesses to people.It is a kind of computer program
Full Text Available The Ebola virus was identified in the year 1976 and has caused periodic outbreaks in West African countries. The disease has a case fatality rate up to 90%. Ebola has been classified as a biosafety level four pathogen and there is no currently approved vaccine or treatment for the virus. However, remarkable progress has been demonstrated by researchers in understanding the pathogenicity of the Ebola virus. Several animal models have been cultivated to develop diagnostics, vaccines and therapeutic drugs.
Yitades; Gebre; Teshome; Gebre; Abena; Peters
The Ebola virus was identified in the year 1976 and has caused periodic outbreaks in West African countries.The disease has a case fatality rate up to 90%.Ebola has been classified as a biosafety level four pathogen and there is no currently approved vaccine or treatment for the virus.However,remarkable progress has been demonstrated by researchers in understanding the pathogenicity of the Ebola virus.Several animal models have been cultivated to develop diagnostics,vaccines and therapeutic drugs.
Kuno, G; Chang, G-J J
Many members of the genus Flavivirus are the agents of important diseases of humans, livestock, and wildlife. Currently, no complete genome sequence is available for the three African viruses, Bagaza, Zika, and Kedougou viruses, each representing a distinct virus subgroup according to the latest virus classification. In this study, we obtained a complete genome sequence of each of those three viruses and characterized the open reading frames (ORFs) with respect to gene sizes, cleavage sites, potential glycosylation sites, distribution of cysteine residues, and unique motifs. The sequences of the three viruses were then scanned across the entire length of the ORF against available sequences of other African flaviviruses and selected reference viruses for genetic relatedness. The data collectively indicated that Kedougou virus was close to dengue viruses but nonetheless distinct, while Bagaza virus shared genetic relatedness with West Nile virus in several genomic regions. In the non-coding regions, it was found that a particular organizational pattern of conserved sequences in the 3' terminal region generally correlated with the current virus grouping.
Weyer, C T; Quan, M; Joone, C; Lourens, C W; MacLachlan, N J; Guthrie, A J
To determine whether subclinical cases, together with clinical cases, of African horse sickness (AHS) occur in immunised horses in field conditions, whole blood samples were collected and rectal temperatures recorded weekly from 50 Nooitgedacht ponies resident in open camps at the Faculty of Veterinary Science, University of Pretoria, Onderstepoort, during 2008-2010. The samples were tested for the presence of African horse sickness virus (AHSV) RNA by a recently developed real-time RT-PCR. It was shown that 16% of immunised horses in an AHS endemic area were infected with AHSV over a 2 year period, with half of these (8%) being subclinically infected. The potential impact of such cases on the epidemiology of AHS warrants further investigation.
Hamiduzzaman, Mollah Md; Guzman-Novoa, Ernesto; Goodwin, Paul H; Reyes-Quintana, Mariana; Koleoglu, Gun; Correa-Benítez, Adriana; Petukhova, Tatiana
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. PMID:25527405
Hamiduzzaman, Mollah Md; Guzman-Novoa, Ernesto; Goodwin, Paul H; Reyes-Quintana, Mariana; Koleoglu, Gun; Correa-Benítez, Adriana; Petukhova, Tatiana
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.
Thais Flores Nogueira Diniz
Full Text Available The article begins by historicizing film adaptation from the arrival of cinema, pointing out the many theoretical approaches under which the process has been seen: from the concept of “the same story told in a different medium” to a comprehensible definition such as “the process through which works can be transformed, forming an intersection of textual surfaces, quotations, conflations and inversions of other texts”. To illustrate this new concept, the article discusses Spike Jonze’s film Adaptation. according to James Naremore’s proposal which considers the study of adaptation as part of a general theory of repetition, joined with the study of recycling, remaking, and every form of retelling. The film deals with the attempt by the scriptwriter Charles Kaufman, cast by Nicholas Cage, to adapt/translate a non-fictional book to the cinema, but ends up with a kind of film which is by no means what it intended to be: a film of action in the model of Hollywood productions. During the process of creation, Charles and his twin brother, Donald, undergo a series of adventures involving some real persons from the world of film, the author and the protagonist of the book, all of them turning into fictional characters in the film. In the film, adaptation then signifies something different from itstraditional meaning. The article begins by historicizing film adaptation from the arrival of cinema, pointing out the many theoretical approaches under which the process has been seen: from the concept of “the same story told in a different medium” to a comprehensible definition such as “the process through which works can be transformed, forming an intersection of textual surfaces, quotations, conflations and inversions of other texts”. To illustrate this new concept, the article discusses Spike Jonze’s film Adaptation. according to James Naremore’s proposal which considers the study of adaptation as part of a general theory of repetition