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Evasion of antibody neutralization in emerging severe acute respiratory syndrome coronaviruses

Yang, Zhi-yong; Werner, Heidi C.; Kong, Wing-pui; Leung, Kwanyee; Traggiai, Elisabetta; Lanzavecchia, Antonio; Nabel, Gary J.
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
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Molecular characterization of the severe acute respiratory syndrome coronavirus has revealed genetic diversity among isolates. The spike (S) glycoprotein, the major target for vaccine and immune therapy, shows up to 17 substitutions in its 1,255-aa sequence; however, the biologic significance of these changes is unknown. Here, the functional effects of S mutations have been determined by analyzing their affinity for a viral receptor, human angiotensin-converting enzyme 2 (hACE-2), and their sensitivity to Ab neutralization with viral pseudotypes. Although minor differences among eight strains transmitted during human outbreaks in early 2003 were found, substantial functional changes were detected in S derived from a case in late 2003 from Guangdong province [S(GD03T0013)] and from two palm civets, S(SZ3) and S(SZ16). S(GD03T0013) depended less on the hACE-2 receptor and was markedly resistant to Ab inhibition. Unexpectedly, Abs that neutralized most human S glycoproteins enhanced entry mediated by the civet virus S glycoproteins. The mechanism of enhancement involved the interaction of Abs with conformational epitopes in the hACE-2-binding domain. Finally, improved immunogens and mAbs that minimize this complication have been defined. These data show that the entry of severe acute respiratory syndrome coronaviruses can be enhanced by Abs...

Civets Are Equally Susceptible to Experimental Infection by Two Different Severe Acute Respiratory Syndrome Coronavirus Isolates

Wu, Donglai; Tu, Changchun; Xin, Chaoan; Xuan, Hua; Meng, Qingwen; Liu, Yonggang; Yu, Yedong; Guan, Yuntao; Jiang, Yu; Yin, Xunnan; Crameri, Gary; Wang, Muping; Li, Changwen; Liu, Shengwang; Liao, Ming; Feng, Li; Xiang, Hua; Sun, Jinfu; Chen, Jinding; Sun
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /02/2005 Português
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Severe acute respiratory syndrome (SARS) was caused by a novel virus now known as SARS coronavirus (SARS-CoV). The discovery of SARS-CoV-like viruses in masked palm civets (Paguma larvata) raises the possibility that civets play a role in SARS-CoV transmission. To test the susceptibility of civets to experimental infection by different SARS-CoV isolates, 10 civets were inoculated with two human isolates of SARS-CoV, BJ01 (with a 29-nucleotide deletion) and GZ01 (without the 29-nucleotide deletion). All inoculated animals displayed clinical symptoms, such as fever, lethargy, and loss of aggressiveness, and the infection was confirmed by virus isolation, detection of viral genomic RNA, and serum-neutralizing antibodies. Our data show that civets were equally susceptible to SARS-CoV isolates GZ01 and BJ01.

Cross-host evolution of severe acute respiratory syndrome coronavirus in palm civet and human

Song, Huai-Dong; Tu, Chang-Chun; Zhang, Guo-Wei; Wang, Sheng-Yue; Zheng, Kui; Lei, Lian-Cheng; Chen, Qiu-Xia; Gao, Yu-Wei; Zhou, Hui-Qiong; Xiang, Hua; Zheng, Hua-Jun; Chern, Shur-Wern Wang; Cheng, Feng; Pan, Chun-Ming; Xuan, Hua; Chen, Sai-Juan; Luo, Hui
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
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The genomic sequences of severe acute respiratory syndrome coronaviruses from human and palm civet of the 2003/2004 outbreak in the city of Guangzhou, China, were nearly identical. Phylogenetic analysis suggested an independent viral invasion from animal to human in this new episode. Combining all existing data but excluding singletons, we identified 202 single-nucleotide variations. Among them, 17 are polymorphic in palm civets only. The ratio of nonsynonymous/synonymous nucleotide substitution in palm civets collected 1 yr apart from different geographic locations is very high, suggesting a rapid evolving process of viral proteins in civet as well, much like their adaptation in the human host in the early 2002–2003 epidemic. Major genetic variations in some critical genes, particularly the Spike gene, seemed essential for the transition from animal-to-human transmission to human-to-human transmission, which eventually caused the first severe acute respiratory syndrome outbreak of 2002/2003.

Receptor and viral determinants of SARS-coronavirus adaptation to human ACE2

Li, Wenhui; Zhang, Chengsheng; Sui, Jianhua; Kuhn, Jens H; Moore, Michael J; Luo, Shiwen; Wong, Swee-Kee; Huang, I-Chueh; Xu, Keming; Vasilieva, Natalya; Murakami, Akikazu; He, Yaqing; Marasco, Wayne A; Guan, Yi; Choe, Hyeryun; Farzan, Michael
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
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Human angiotensin-converting enzyme 2 (ACE2) is a functional receptor for SARS coronavirus (SARS-CoV). Here we identify the SARS-CoV spike (S)-protein-binding site on ACE2. We also compare S proteins of SARS-CoV isolated during the 2002–2003 SARS outbreak and during the much less severe 2003–2004 outbreak, and from palm civets, a possible source of SARS-CoV found in humans. All three S proteins bound to and utilized palm-civet ACE2 efficiently, but the latter two S proteins utilized human ACE2 markedly less efficiently than did the S protein obtained during the earlier human outbreak. The lower affinity of these S proteins could be complemented by altering specific residues within the S-protein-binding site of human ACE2 to those of civet ACE2, or by altering S-protein residues 479 and 487 to residues conserved during the 2002–2003 outbreak. Collectively, these data describe molecular interactions important to the adaptation of SARS-CoV to human cells, and provide insight into the severity of the 2002–2003 SARS epidemic.

Molecular Evolution Analysis and Geographic Investigation of Severe Acute Respiratory Syndrome Coronavirus-Like Virus in Palm Civets at an Animal Market and on Farms‡

Kan, Biao; Wang, Ming; Jing, Huaiqi; Xu, Huifang; Jiang, Xiugao; Yan, Meiying; Liang, Weili; Zheng, Han; Wan, Kanglin; Liu, Qiyong; Cui, Buyun; Xu, Yanmei; Zhang, Enmin; Wang, Hongxia; Ye, Jingrong; Li, Guichang; Li, Machao; Cui, Zhigang; Qi, Xiaobao; Che
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /09/2005 Português
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Massive numbers of palm civets were culled to remove sources for the reemergence of severe acute respiratory syndrome (SARS) in Guangdong Province, China, in January 2004, following SARS coronavirus detection in market animals. The virus was identified in all 91 palm civets and 15 raccoon dogs of animal market origin sampled prior to culling, but not in 1,107 palm civets later sampled at 25 farms, spread over 12 provinces, which were claimed to be the source of traded animals. Twenty-seven novel signature variation residues (SNVs) were identified on the spike gene and were analyzed for their phylogenetic relationships, based on 17 sequences obtained from animals in our study and from other published studies. Analysis indicated that the virus in palm civets at the live-animal market had evolved to infect humans. The evolutionary starting point was a prototype group consisting of three viral sequences of animal origin. Initially, seven SNV sites caused six amino acid changes, at positions 147, 228, 240, 479, 821, and 1080 of the spike protein, to generate low-pathogenicity viruses. One of these was linked to the first SARS patient in the 2003-2004 period. A further 14 SNVs caused 11 amino acid residue changes, at positions 360, 462, 472...

Severe acute respiratory syndrome coronavirus-like virus in Chinese horseshoe bats

Lau, Susanna K. P.; Woo, Patrick C. Y.; Li, Kenneth S. M.; Huang, Yi; Tsoi, Hoi-Wah; Wong, Beatrice H. L.; Wong, Samson S. Y.; Leung, Suet-Yi; Chan, Kwok-Hung; Yuen, Kwok-Yung
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
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Although the finding of severe acute respiratory syndrome coronavirus (SARS-CoV) in caged palm civets from live animal markets in China has provided evidence for interspecies transmission in the genesis of the SARS epidemic, subsequent studies suggested that the civet may have served only as an amplification host for SARS-CoV. In a surveillance study for CoV in noncaged animals from the wild areas of the Hong Kong Special Administration Region, we identified a CoV closely related to SARS-CoV (bat-SARS-CoV) from 23 (39%) of 59 anal swabs of wild Chinese horseshoe bats (Rhinolophus sinicus) by using RT-PCR. Sequencing and analysis of three bat-SARS-CoV genomes from samples collected at different dates showed that bat-SARS-CoV is closely related to SARS-CoV from humans and civets. Phylogenetic analysis showed that bat-SARS-CoV formed a distinct cluster with SARS-CoV as group 2b CoV, distantly related to known group 2 CoV. Most differences between the bat-SARS-CoV and SARS-CoV genomes were observed in the spike genes, ORF 3 and ORF 8, which are the regions where most variations also were observed between human and civet SARS-CoV genomes. In addition, the presence of a 29-bp insertion in ORF 8 of bat-SARS-CoV genome, not in most human SARS-CoV genomes...

Molecular Evolution Analysis and Geographic Investigation of Severe Acute Respiratory Syndrome Coronavirus-Like Virus in Palm Civets at an Animal Market and on Farms

Kan, Biao; Wang, Ming; Jing, Huaiqi; Xu, Huifang; Jiang, Xiugao; Yan, Meiying; Liang, Weili; Zheng, Han; Wan, Kanglin; Liu, Qiyong; Cui, Buyun; Xu, Yanmei; Zhang, Enmin; Wang, Hongxia; Ye, Jingrong; Li, Guichang; Li, Machao; Cui, Zhigang; Qi, Xiaobao; Che
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /08/2006 Português
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Evolutionary Insights into the Ecology of Coronaviruses▿

Vijaykrishna, D.; Smith, G. J. D.; Zhang, J. X.; Peiris, J. S. M.; Chen, H.; Guan, Y.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
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Although many novel members of the Coronaviridae have recently been recognized in different species, the ecology of coronaviruses has not been established. Our study indicates that bats harbor a much wider diversity of coronaviruses than any other animal species. Dating of different coronavirus lineages suggests that bat coronaviruses are older than those recognized in other animals and that the human severe acute respiratory syndrome (SARS) coronavirus was directly derived from viruses from wild animals in wet markets of southern China. Furthermore, the most closely related bat and SARS coronaviruses diverged in 1986, an estimated divergence time of 17 years prior to the outbreak, suggesting that there may have been transmission via an unknown intermediate host. Analysis of lineage-specific selection pressure also indicated that only SARS coronaviruses in civets and humans were under significant positive selection, also demonstrating a recent interspecies transmission. Analysis of population dynamics revealed that coronavirus populations in bats have constant population growth, while viruses from all other hosts show epidemic-like increases in population. These results indicate that diverse coronaviruses are endemic in different bat species...

Natural Mutations in the Receptor Binding Domain of Spike Glycoprotein Determine the Reactivity of Cross-Neutralization between Palm Civet Coronavirus and Severe Acute Respiratory Syndrome Coronavirus▿

Liu, Li; Fang, Qing; Deng, Fei; Wang, Hanzhong; Yi, Christopher E.; Ba, Lei; Yu, Wenjie; Lin, Richard D.; Li, Taisheng; Hu, Zhihong; Ho, David D.; Zhang, Linqi; Chen, Zhiwei
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
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The severe acute respiratory syndrome (SARS) outbreak of 2002 and 2003 occurred as a result of zoonotic transmission. Coronavirus (CoV) found in naturally infected palm civet (civet-CoV) represents the closest genetic relative to SARS-CoV, but the degree and the determinants of cross-neutralization among these viruses remain to be investigated. Studies indicate that the receptor binding domain (RBD) of the SARS-CoV spike (S) glycoprotein contains major determinants for viral entry and neutralization. We aim to characterize the impact of natural mutations within the RBDs of civet-CoVs on viral entry and cross-neutralization. In this study, the S glycoprotein genes were recovered from naturally infected civets in central China (Hubei province), extending the geographic distribution of civet-CoV beyond the southeastern province of Guangdong. Moreover, pseudoviruses generated in our laboratory with four civet S genes, each with a distinct RBD, infected cells expressing human receptor angiotensin-converting enzyme 2, but with 90 to 95% less efficiency compared to that of SARS-CoV. These four civet S genes were also constructed as DNA vaccines to immunize mice. Immunized sera elicited against most civet S glycoproteins displayed potent neutralizing activities against autologous viruses but were much less efficient (50% inhibitory concentration...

Potent cross-reactive neutralization of SARS coronavirus isolates by human monoclonal antibodies

Zhu, Zhongyu; Chakraborti, Samitabh; He, Yuxian; Roberts, Anjeanette; Sheahan, Tim; Xiao, Xiaodong; Hensley, Lisa E.; Prabakaran, Ponraj; Rockx, Barry; Sidorov, Igor A.; Corti, Davide; Vogel, Leatrice; Feng, Yang; Kim, Jae-Ouk; Wang, Lin-Fa; Baric, Ralph;
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
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The severe acute respiratory syndrome coronavirus (SARS-CoV) caused a worldwide epidemic in late 2002/early 2003 and a second outbreak in the winter of 2003/2004 by an independent animal-to-human transmission. The GD03 strain, which was isolated from an index patient of the second outbreak, was reported to resist neutralization by the human monoclonal antibodies (hmAbs) 80R and S3.1, which can potently neutralize isolates from the first outbreak. Here we report that two hmAbs, m396 and S230.15, potently neutralized GD03 and representative isolates from the first SARS outbreak (Urbani, Tor2) and from palm civets (SZ3, SZ16). These antibodies also protected mice challenged with the Urbani or recombinant viruses bearing the GD03 and SZ16 spike (S) glycoproteins. Both antibodies competed with the SARS-CoV receptor, ACE2, for binding to the receptor-binding domain (RBD), suggesting a mechanism of neutralization that involves interference with the SARS-CoV–ACE2 interaction. Two putative hot-spot residues in the RBD (Ile-489 and Tyr-491) were identified within the SARS-CoV spike that likely contribute to most of the m396-binding energy. Residues Ile-489 and Tyr-491 are highly conserved within the SARS-CoV spike, indicating a possible mechanism of the m396 cross-reactivity. Sequence analysis and mutagenesis data show that m396 might neutralize all zoonotic and epidemic SARS-CoV isolates with known sequences...

Synthetic Reconstruction of Zoonotic and Early Human Severe Acute Respiratory Syndrome Coronavirus Isolates That Produce Fatal Disease in Aged Mice▿

Rockx, Barry; Sheahan, Timothy; Donaldson, Eric; Harkema, Jack; Sims, Amy; Heise, Mark; Pickles, Raymond; Cameron, Mark; Kelvin, David; Baric, Ralph
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
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The severe acute respiratory syndrome (SARS) epidemic was characterized by high mortality rates in the elderly. The molecular mechanisms that govern enhanced susceptibility of elderly populations are not known, and robust animal models are needed that recapitulate the increased pathogenic phenotype noted with increasing age. Using synthetic biology and reverse genetics, we describe the construction of a panel of isogenic SARS coronavirus (SARS-CoV) strains bearing variant spike glycoproteins that are representative of zoonotic strains found in palm civets and raccoon dogs, as well as isolates spanning the early, middle, and late phases of the SARS-CoV epidemic. The recombinant viruses replicated efficiently in cell culture and demonstrated variable sensitivities to neutralization with antibodies. The human but not the zoonotic variants replicated efficiently in human airway epithelial cultures, supporting earlier hypotheses that zoonotic isolates are less pathogenic in humans but can evolve into highly pathogenic strains. All viruses replicated efficiently, but none produced clinical disease or death in young animals. In contrast, severe clinical disease, diffuse alveolar damage, hyaline membrane formation, alveolitis, and death were noted in 12-month-old mice inoculated with the palm civet HC/SZ/61/03 strain or early-human-phase GZ02 variants but not with related middle- and late-phase epidemic or raccoon dog strains. This panel of SARS-CoV recombinants bearing zoonotic and human epidemic spike glycoproteins will provide heterologous challenge models for testing vaccine efficacy against zoonotic reintroductions as well as provide the appropriate model system for elucidating the complex virus-host interactions that contribute to more-severe and fatal SARS-CoV disease and acute respiratory distress in the elderly.

Structural Analysis of Major Species Barriers between Humans and Palm Civets for Severe Acute Respiratory Syndrome Coronavirus Infections▿

Li, Fang
Fonte: American Society for Microbiology (ASM) Publicador: American Society for Microbiology (ASM)
Tipo: Artigo de Revista Científica
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It is believed that a novel coronavirus, severe acute respiratory syndrome coronavirus (SARS-CoV), was passed from palm civets to humans and caused the epidemic of SARS in 2002 to 2003. The major species barriers between humans and civets for SARS-CoV infections are the specific interactions between a defined receptor-binding domain (RBD) on a viral spike protein and its host receptor, angiotensin-converting enzyme 2 (ACE2). In this study a chimeric ACE2 bearing the critical N-terminal helix from civet and the remaining peptidase domain from human was constructed, and it was shown that this construct has the same receptor activity as civet ACE2. In addition, crystal structures of the chimeric ACE2 complexed with RBDs from various human and civet SARS-CoV strains were determined. These structures, combined with a previously determined structure of human ACE2 complexed with the RBD from a human SARS-CoV strain, have revealed a structural basis for understanding the major species barriers between humans and civets for SARS-CoV infections. They show that the major species barriers are determined by interactions between four ACE2 residues (residues 31, 35, 38, and 353) and two RBD residues (residues 479 and 487), that early civet SARS-CoV isolates were prevented from infecting human cells due to imbalanced salt bridges at the hydrophobic virus/receptor interface...

Antibodies to SARS Coronavirus in Civets

Tu, Changchun; Crameri, Gary; Kong, Xiangang; Chen, Jinding; Sun, Yanwei; Yu, Meng; Xiang, Hua; Xia, Xianzhu; Liu, Shengwang; Ren, Tao; Yu, Yedong; Eaton, Bryan T.; Xuan, Hua; Wang, Lin-Fa
Fonte: Centers for Disease Control and Prevention Publicador: Centers for Disease Control and Prevention
Tipo: Artigo de Revista Científica
Publicado em /12/2004 Português
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Using three different assays, we examined 103 serum samples collected from different civet farms and a market in China in June 2003 and January 2004. While civets on farms were largely free from SARS-CoV infection, ≈80% of the animals from one animal market in Guangzhou contained significant levels of antibody to SARS-CoV, which suggests no widespread infection among civets resident on farms, and the infection of civets in the market might be associated with trading activities under the conditions of overcrowding and mixing of various animal species.

CIVETS motivaciones y condiciones para la atracción de IED

Flechas Báez, Camilo; Muñoz Briceño, Miguel Andrés
Fonte: Pontifícia Universidade Javeriana Publicador: Pontifícia Universidade Javeriana
Tipo: bachelorThesis; Trabajo de Grado Pregrado Formato: Pdf
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Este trabajo de grado es una tesis deductiva sobre las motivaciones y condiciones que reúnen los países catalogados como CIVETS para la atracción de inversión extranjera directa. Brinda una visión comparativa entre los países (Colombia, Indonesia, Vietnam, Egipto, Turquía y Sudáfrica) por medio de un análisis de factores políticos, económicos, geográficos y demográficos que permiten concluir la convergencia existente entre estos.; This is a deductive thesis about the motivations and conditions that the CIVETS have to attract foreign direct investment. It gives a comparative vision between (Colombia, Indonesia, Vietnam, Turkey, Egypt, South Africa) through an analysis of political, economical, geographical and demographical factors that let know the convergence between these countries.

Las naciones o mercados emergentes del CIVETS (Borrador de administración No. 49)

Vieira Posada, Edgar
Fonte: Colégio de Estudos Superiores de Administração Publicador: Colégio de Estudos Superiores de Administração
Formato: application/pdf
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El presente borrador de administración es un trabajo de opinión o nota pedagógica de orientación inicial sobre el tema de la conformación de un grupo de naciones emergentes: Colombia, Indonesia, Vietnam, Egipto, Turquía y Sudáfrica, agrupadas bajo el acrónimo de CIVETS. Es un tema nuevo sobre el cual no existe aún bibliografía de investigación científica amplia y suficiente, pero que merece comenzar a ser tratado para llamar la atención sobre el potencial que habría para estas naciones de lograr una mejor inserción en el contexto de un mundo globalizado, y motivar la realización de estudios más detallados.

Primer concurso de debate "COLOMBIA Y LOS CIVETS EN LA ECONOMÍA GLOBAL"

Colegio de Estudios Superiores de Administración -CESA-
Fonte: Colégio de Estudos Superiores de Administração Publicador: Colégio de Estudos Superiores de Administração
Formato: video/x-flv
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La Dirección de Pregrado y el Centro DIGA organizaron el Primer Concurso de Debate CESA entre los alumnos de pregrado.

Relación entre las emisiones de co2, el consumo de energía y el pib: el caso de los civets

Campo Robledo, Jacobo; Olivares, Wilmer
Fonte: Universidad de Medellín Publicador: Universidad de Medellín
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Article Formato: application/pdf; application/pdf
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Este trabajo evalúa la relación que existe entre las emisiones de CO2 (dióxido de carbono), el consumo deenergía y el PIB, para el grupo de países conocido como los CIVETS (Colombia, Indonesia, Vietnam, Egipto,Turquía y Sudáfrica), en el período 1985-2007. Para comprobar dichas relaciones se utiliza la metodologíade datos de panel no estacionarios, acompañada de pruebas de raíces unitarias y de cointegración. Seconcluye que, en el largo plazo, el crecimiento económico y el consumo de energía son determinantesdel calentamiento global a través del incremento en las emisiones de CO2 para los CIVETS. Finalmente,se presenta evidencia empírica que comprueba la existencia de una Curva de Kuznets Ambiental para elgrupo de países estudiado, que permite demostrar que los incrementos en el PIB per cápita incrementanlas emisiones de CO2, pero a partir de determinado nivel de PIB las emisiones disminuyen

Development and Evaluation of a Multitarget Real-Time Taqman Reverse Transcription-PCR Assay for Detection of the Severe Acute Respiratory Syndrome-Associated Coronavirus and Surveillance for an Apparently Related Coronavirus Found in Masked Palm Civets

Hu, Wenqian; Bai, Bingke; Hu, Zhihong; Chen, Ze; An, Xuefang; Tang, Lijun; Yang, Jihong; Wang, Hualin; Wang, Hanzhong
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /05/2005 Português
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Severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV) is the etiological agent of SARS. It is believed that SARS-CoV originates from wild animals. We have developed a multitarget real-time Taqman reverse transcription-PCR (RT-PCR) assay for the quantitative detection of SARS-CoV. The sequences of the Taqman probes with a minor groove binder and the corresponding primers were based on the sequences of the N gene, open reading frame (ORF) 3, and ORF 8. The overall linear range of this assay was from at least 101 to 106 copies per reaction, and the detection limit could reach less than 10 copies per reaction. The quantification results for SARS-CoV from cell culture correlated well with those of the RT-PCR by using any two of the three sets of primer and probe used in this assay. However, the results of quantification of SARS-CoV obtained by using a few available throat swab specimens from SARS patients and the N gene as the target were almost 10 times higher than those obtained by using ORF 3 and ORF 8. Using this assay, we also detected an apparently SARS-CoV-related coronavirus in the throat swab specimens from masked palm civets in the west part of Hubei Province, People's Republic of China.

SARS-CoV originated from bats in 1998 and may still exist in humans

Tao, Ailin; Huang, Yuyi; Li, Peilu; Liu, Jun; Zhong, Nanshan; Zhang, Chiyu
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
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SARS-CoV is believed to originate from civets and was thought to have been eliminated as a threat after the 2003 outbreak. Here, we show that human SARS-CoV (huSARS-CoV) originated directly from bats, rather than civets, by a cross-species jump in 1991, and formed a human-adapted strain in 1998. Since then huSARS-CoV has evolved further into highly virulent strains with genotype T and a 29-nt deletion mutation, and weakly virulent strains with genotype C but without the 29-nt deletion. The former can cause pneumonia in humans and could be the major causative pathogen of the SARS outbreak, whereas the latter might not cause pneumonia in humans, but evolved the ability to co-utilize civet ACE2 as an entry receptor, leading to interspecies transmission between humans and civets. Three crucial time points - 1991, for the cross-species jump from bats to humans; 1998, for the formation of the human-adapted SARS-CoV; and 2003, when there was an outbreak of SARS in humans - were found to associate with anomalously low annual precipitation and high temperatures in Guangdong. Anti-SARS-CoV sero-positivity was detected in 20% of all the samples tested from Guangzhou children who were born after 2005, suggesting that weakly virulent huSARS-CoVs might still exist in humans. These existing but undetected SARS-CoVs have a large potential to evolve into highly virulent strains when favorable climate conditions occur...

A comparative study of foreign economic policies: the CIVETS countries

Guerra-Barón, Angélica; Méndez, Álvaro
Fonte: London School of Economics and Political Science, Global South Unit Publicador: London School of Economics and Political Science, Global South Unit
Tipo: Monograph; NonPeerReviewed Formato: application/pdf
Publicado em //2015 Português
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Colombia, Indonesia, Vietnam, Egypt, Turkey, and South Africa (CIVETS) have shaped their foreign economic policies in line with the Washington Consensus and have implemented strategies to attract foreign investment as a possible way out of the current financial crisis. Once multilateral trade rules were agreed under the WTO, these countries revised their domestic trade policies in order to cope with both the organisational principles and the international investment standards promoted by international financial institutions. Despite the fact that transnational economic groups have been focussing their attention on these ‘new investment miracles’ since the coining of the term CIVETS in 2009, the CIVETS governments have shown no interest in coordinating their foreign economic policies on investment issues. In this paper we argue that the emerging economies of CIVETS exemplify a case of unintended foreign economic policy convergence, facilitated by systemic causes. These include their common need to overcome historic processes of adverse economic transition while getting inserted successfully into world trade; as well as domestic variables like the similar ideas of CIVETS policy makers.