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Search Results: 1 - 10 of 107 matches for " coronavirus "
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Coronavirus Genomics and Bioinformatics Analysis
Patrick C. Y. Woo,Yi Huang,Susanna K. P. Lau,Kwok-Yung Yuen
Viruses , 2010, DOI: 10.3390/v2081803
Abstract: The drastic increase in the number of coronaviruses discovered and coronavirus genomes being sequenced have given us an unprecedented opportunity to perform genomics and bioinformatics analysis on this family of viruses. Coronaviruses possess the largest genomes (26.4 to 31.7 kb) among all known RNA viruses, with G + C contents varying from 32% to 43%. Variable numbers of small ORFs are present between the various conserved genes (ORF1ab, spike, envelope, membrane and nucleocapsid) and downstream to nucleocapsid gene in different coronavirus lineages. Phylogenetically, three genera, Alphacoronavirus, Betacoronavirus and Gammacoronavirus, with Betacoronavirus consisting of subgroups A, B, C and D, exist. A fourth genus, Deltacoronavirus, which includes bulbul coronavirus HKU11, thrush coronavirus HKU12 and munia coronavirus HKU13, is emerging. Molecular clock analysis using various gene loci revealed that the time of most recent common ancestor of human/civet SARS related coronavirus to be 1999-2002, with estimated substitution rate of 4′10-4 to 2′10-2 substitutions per site per year. Recombination in coronaviruses was most notable between different strains of murine hepatitis virus (MHV), between different strains of infectious bronchitis virus, between MHV and bovine coronavirus, between feline coronavirus (FCoV) type I and canine coronavirus generating FCoV type II, and between the three genotypes of human coronavirus HKU1 (HCoV-HKU1). Codon usage bias in coronaviruses were observed, with HCoV-HKU1 showing the most extreme bias, and cytosine deamination and selection of CpG suppressed clones are the two major independent biological forces that shape such codon usage bias in coronaviruses.
Betancourt,A; Rodríguez,Edisleidy; Joa,R; Ancizar,J.A; López,A; Relova,Damaris; Barrera,Maritza;
Revista de Salud Animal , 2009,
Abstract: the experimental reproduction of diarrheas was achieved in newborn calves deprived from calostrum, after inoculation by oral route of a bovine coronavirus strain, guayabal. diarrheas appeared at 24 hours post-inoculation. in all inoculated calves, anatomo and histopathological lesions which corresponded to the disease were observed in necropsy. bovine coronavirus was excreted after the establishment of diarrhea and not any other pathogenic microorganism involved was found. this sustained the enteropathogenicity of the guayabal strain.
Preparation, characterization and preliminary in vivo studies of inactivated SARS-CoV vaccine
Lin Tang,Jian Wang,Ede Qin,Qingyu Zhu,Man Yu,Zhifen Ding,Huiying Shi,Xiaojie Cheng,Caiping Wang,Guohui Chang,Shuangli Li,Xumin Zhang,Xishu Chen,Jun Yu,Ze Chen
Chinese Science Bulletin , 2003, DOI: 10.1360/03wc464
Abstract: A large quantity of SARS-CoV virus was proliferated in Vero cells, inactivated with β-propiolactone, then purified by Sepharose 4FF column chromatography to prepare inactivated vaccine. The vaccine was identified by Western blot, mass spectrographic analysis, ELISA and electron microscopy. The vaccine with or without aluminum hydroxide adjuvant was inoculated into female BALB/c mice at different dosages. The result showed that the antibodies to SARS-CoV were induced in the mice. The antibody levels induced by the vaccine with aluminum hydroxide were higher than those without aluminum hydroxide.
Severe acute respiratory syndrome
Thomas P
Indian Journal of Medical Microbiology , 2003,
Abstract: Severe acute respiratory syndrome (SARS) is a form of atypical pneumonia that apparently originated in Guangdong Province of the People′s Republic of China in late 2002. This first came to the world′s attention in late February 2003, and has since spread worldwide. As of June 23rd 2003, the disease had been reported from 32 countries or regions globally, affecting 8459 people; 805 individuals (9.5 % of the total affected) have died of the disease. A novel coronavirus, the SARS-associated coronavirus (SARS- CoV) has been found in various specimens taken from patients with SARS. Although there has been rapid development of tests to detect SARS Co-V, these tests presently have certain limitations. Definitions of suspected, confirmed and probable cases have been formulated. Measures currently used for the management of patients with SARS include isolation, ribavirin, corticosteroid therapy and mechanical ventilation. Unfortunately, almost 10 % of affected patients succumb to their illness, underlying the need for developing more effective therapy. It remains to be seen how long it will take to bring this epidemic under control.
Coronavirus–associated enteritis in a quail farm
Elena Circella,Vito Martella,Giordano Bruni,Eleonora Lorusso
Italian Journal of Animal Science , 2010, DOI: 10.4081/ijas.2007.326
Abstract: An enteric syndrome observed in semi-intensively reared quails is described. The affected birds showed depression, severe diarrhoea and dehydration. The mortality occurred particularly in young birds. At necropsy, the prominent lesion was catarrhal enteritis. Laboratory investigations demonstrated the presence of coronavirus in the gut of dead animals. No additional pathogens were detected. To our knowledge, this is the first evidence for the presence of CoVs in quail with enteritis.
Recombination in Avian Gamma-Coronavirus Infectious Bronchitis Virus
Sharmi W. Thor,Deborah A. Hilt,Jessica C. Kissinger,Andrew H. Paterson,Mark W. Jackwood
Viruses , 2011, DOI: 10.3390/v3091777
Abstract: Recombination in the family Coronaviridae has been well documented and is thought to be a contributing factor in the emergence and evolution of different coronaviral genotypes as well as different species of coronavirus. However, there are limited data available on the frequency and extent of recombination in coronaviruses in nature and particularly for the avian gamma-coronaviruses where only recently the emergence of a turkey coronavirus has been attributed solely to recombination. In this study, the full-length genomes of eight avian gamma-coronavirus infectious bronchitis virus (IBV) isolates were sequenced and along with other full-length IBV genomes available from GenBank were analyzed for recombination. Evidence of recombination was found in every sequence analyzed and was distributed throughout the entire genome. Areas that have the highest occurrence of recombination are located in regions of the genome that code for nonstructural proteins 2, 3 and 16, and the structural spike glycoprotein. The extent of the recombination observed, suggests that this may be one of the principal mechanisms for generating genetic and antigenic diversity within IBV. These data indicate that reticulate evolutionary change due to recombination in IBV, likely plays a major role in the origin and adaptation of the virus leading to new genetic types and strains of the virus.
Detection of Coronavirus in Capybaras (Hydrochoeris hydrochaeris) by Transmission Electron Microscopy in S?o Paulo, Brazil
Catroxo,M. H. B; Miranda,L.B; Lavorenti,A; Petrella,S; Melo,N. A; Martins,A. M. C. P. R. F;
International Journal of Morphology , 2010, DOI: 10.4067/S0717-95022010000200035
Abstract: coronaviruses are enveloped, positive-stranded rna, belongs to the nidovirales order, coronaviridae family and are classified into three groups. groups 3a and 3c comprising the avian coronaviruses. they are worldwide in distribution and can cause respiratory, enteric and in some cases hepatitis and neurological diseases in a wide variety of animals, resulting in economic losses to breeders and breeding. in this study, we describe an outbreak of diarrhea in a herd of capybaras found in the city of piracicaba, s?o paulo, brazil. the animals had sudden symptoms of anorexia, profuse and watery diarrhea, yellowish or greenish, dehydration, weight loss, sharp and twisting of limbs leading to death in less than a week, mostly weaned and with an age of three months. a total of 59 stool samples and 10 fragments of small intestine were processed for negative staining technique (rapid preparation). by transmission electron microscope a large number of particles with morphology similar to coronavirus, pleomorphic, rounded or elongated features with radial projections form a corona and measuring 80-140 nm in diameter, was visualized in all samples analyzed. the technique was extremely useful for rapid viral diagnosis in the affected animals.
Rapid detection of bovine coronavirus by a semi-nested RT-PCR
Asano, Karen M.;Souza, Sibele P.;Silva, Sheila O.S.;Richtzenhain, Leonardo J.;Brand?o, Paulo E.;
Pesquisa Veterinária Brasileira , 2009, DOI: 10.1590/S0100-736X2009001100001
Abstract: bovine coronavirus (bcov) is a member of the group 2 of the coronavirus (nidovirales: coronaviridae) and the causative agent of enteritis in both calves and adult bovine, as well as respiratory disease in calves. the present study aimed to develop a semi-nested rt-pcr for the detection of bcov based on representative up-to-date sequences of the nucleocapsid gene, a conserved region of coronavirus genome. three primers were designed, the first round with a 463bp and the second (semi-nested) with a 306bp predicted fragment. the analytical sensitivity was determined by 10-fold serial dilutions of the bcov kakegawa strain (ha titre: 256) in depc treated ultra-pure water, in fetal bovine serum (fbs) and in a bcov-free fecal suspension, when positive results were found up to the 10-2, 10-3 and 10-7 dilutions, respectively, which suggests that the total amount of rna in the sample influence the precipitation of pellets by the method of extraction used. when fecal samples was used, a large quantity of total rna serves as carrier of bcov rna, demonstrating a high analytical sensitivity and lack of possible substances inhibiting the pcr. the final semi-nested rt-pcr protocol was applied to 25 fecal samples from adult cows, previously tested by a nested rt-pcr rdrp used as a reference test, resulting in 20 and 17 positives for the first and second tests, respectively, and a substantial agreement was found by kappa statistics (0.694). the high sensitivity and specificity of the new proposed method and the fact that primers were designed based on current bcov sequences give basis to a more accurate diagnosis of bcov-caused diseases, as well as to further insights on protocols for the detection of other coronavirus representatives of both animal and public health importance.
On the etiology of an outbreak of winter dysentery in dairy cows in Brazil
Brand?o, Paulo E.;Villarreal, Laura Y.B.;Gregori, F.;Souza, Silvio L.P. de;Lopes, Marco A.E.;Gomes, Cleise R.;Sforsin, Angelo J.;Sanches, Alexandre A.;Rosales, Cesar A.R.;Richtzenhain, Leonardo J.;Ferreira, Antonio J.P.;Jerez, José A.;
Pesquisa Veterinária Brasileira , 2007, DOI: 10.1590/S0100-736X2007001000002
Abstract: winter dysentery (wd) is a seasonal infectious disease described worldwide that causes a marked decrease in milk production in dairy cows. in the northern hemisphere, where the disease is classically recognized, bovine coronavirus (bcov) has been assigned as a major etiologic agent of the disease. nonetheless, in the southern hemisphere, an in-deep etiological survey on wd cases had not been carried out. this study aimed to survey for bcov by nested-rt-pcr, rotavirus by polyacrylamide gel electrophoresis (page) and elisa, bacteria by classical bacteriological methods and pcr for virulence factors and parasites by sugar flotation test on fecal samples of 21 cows from a farm during an outbreak of wd in s?o paulo state, southeastern brazil. bcov was detected in all 21 samples, while rotavirus was detected in two symptomatic cows. escherichia coli, yersinia intermedia, providencia rustigianii proteus penneri, klebsiella terrigena and enterobacter aglomerans were detected in samples from both asymptomatic and healthy cows in different associations. the study of e. coli virulence factors revealed that the strains isolated were all apathogenic. cysts of eimeria sp. and eggs of strongyloidea were detected at low numbers in four of the symptomatic cows, with one co-infestation. these results suggest bcov as the main etiologic agent of the cases of wd in brazil, a conclusion that, with the clinical and epidemiological patterns of the disease studied herein, match those already described elsewhere. these findings give basis to the development of preventive measures and contribute to the understanding of the etiology of wd.
Identification of turkey astrovirus and turkey coronavirus in an outbreak of Poult Enteritis and Mortality Syndrome
Villarreal, LYB;Assayag, MS;Brand?o, PE;Chacón, JLV;Bunger, AND;Astolfi-Ferreira, CS;Gomes, CR;Jones, RC;Ferreira, AJP;
Revista Brasileira de Ciência Avícola , 2006, DOI: 10.1590/S1516-635X2006000200010
Abstract: this article reports a survey on turkey astrovirus (tastv) and turkey coronavirus (tcov) infections with rt-pcr in 17 turkey flocks affected by acute enteritis and two apparently normal turkey flocks located in the southeastern region of brazil by pcr (tastv and tcov). seven out of the 17 affected flocks were positive for tastv and 14 for tcov, with seven co-infections. in one of the two apparently normal flocks, a tastv-tcov co-infection was found. although a definitive association of these agents and the signs can not be made, the implications of these findings are discussed.
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