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Terapêutica farmacológica antiviral específica em infecções por Picornavírus

Sousa, Inês Escudero de
Fonte: [s.n.] Publicador: [s.n.]
Tipo: Dissertação de Mestrado
Publicado em //2011 POR
Relevância na Pesquisa
17.02%
Trabalho apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas; A família Picornaviridae consiste em mais de 200 espécies de vírus associados a enumeras doenças com um elevado interesse clínico, entre as quais, poliomielite, meningite asséptica, constipação e encefalite. Esta família engloba 12 géneros, quatro dos quais (Enterovírus, Hepatovírus, Parechovírus e Kobuvírus) são patogénicos para o homem. Os picornavírus são vírus de RNA positivo constituídos por uma cápside icosaédrica regular. Estes vírus são responsáveis por infecções endémicas, como é o caso do Poliovírus e infecções de carácter epidémico como no caso do Rhinovírus. A intensidade da doença é muito variável, uma vez que na maior parte dos casos estamos perante uma doença assintomática ou um quadro clínico ligeiro que apresenta uma resolução espontânea, mas em outros casos pode originar um quadro patológico grave. Até ao momento não existe nenhuma molécula aprovada para o tratamento específico de infecção por picornavírus. No entanto devido à gravidade de determinadas doenças como é o caso da poliomielite e da hepatite foram desenvolvidas vacinas de modo...

Emergent viruses in the marine environment; Vírus emergentes do ambiente marinho

Sousa, Sónia de Fátima Félix Ferreira de
Fonte: Universidade de Aveiro Publicador: Universidade de Aveiro
Tipo: Dissertação de Mestrado
ENG
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The enteric viruses generally are transmitted by the fecal-oral route and constitute a threat for the public health. They can be transmitted from the marine environment through the ingestion of recreational waters or through the consumption of bivalves, being its transmission from the marine environment considered many times emergent. Water virology started around half a century ago, with scientists attempting to detect poliovirus in water samples. Since that time, other enteric viruses were found to be responsible for outbreaks of gastroenteritis and hepatitis. The majority of the enteric viruses that have a sea waterborne transmission belong to the families Caliciviridae, Adenoviridae, Picornaviridae and Reoviridae. This work has as objectives to evaluate the importance of the transmission of enteric viruses for the marine environment, reviewing the factors that affect its survival in this environment and enumerating the cases of emergent transmission. Many factors could influence their surveillance in marine environments, such as water temperature, UV radiation, pH, salinity, raining, and adsorption to sediments among others. The number of outbreaks of viral gastroenteritis has increased in the developed countries of Europe and North America. Caliciviridae family and hepatitis A viruses of Picornaviridae family are responsible for the majority of the waterborne gastroenteritis outbreaks...

Rastreio virológico em espécies selvagens de roedores pertencentes à fauna portuguesa

Carvalho, Alexandra Cardoso Ribeiro de
Fonte: Universidade de Lisboa Publicador: Universidade de Lisboa
Tipo: Dissertação de Mestrado
Publicado em //2011 POR
Relevância na Pesquisa
17.02%
Tese de mestrado. Biologia (Microbiologia Aplicada). Universidade de Lisboa, Faculdade de Ciências, 2011; Emergent viral zoonosis are a major concern in this global age, not only as a public health threat, but also because of its implications on livestock production and wildlife conservation. With this in mind, we have conducted a study to survey the presence of viruses belonging to different viral families in several species of wild rodents captured in Central and Southern Portugal, using molecular techniques. We focused not only on well-known zoonotic viruses (e.g. genus Hantavirus, Bunyaviridae; genus Arenavirus, Arenaviridae; and genus Flavivirus, Flaviviridae), but also on putative zoonotic agents, such as Encephalomyocarditis virus (EMCV) (Picornaviridae), and other previously described muroid viruses that albeit non-zoonotic, can be used as surrogate models of similar human infections (e.g. Herpesviridae). Our results seem to indicate that the presence of zoonotic viruses, rodent-borne or with rodent reservoirs, is not widespread in Portugal, but we have to bear in mind the small sampling size. In fact, we have only found one true-positive amplification. A Microtus lusitanicus vole captured in Portalegre was PCR positive to EMC virus. Due to the 100% similarity between the viral sequence we have found and the one of the EMCV isolate used as a positive control...

Conserved RNA secondary structures in Picornaviridae genomes

Witwer, Christina; Rauscher, Susanne; Hofacker, Ivo L.; Stadler, Peter F.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
Publicado em 15/12/2001 EN
Relevância na Pesquisa
27.31%
The family Picornaviridae contains important pathogens including, for example, hepatitis A virus and foot-and-mouth disease virus. The genome of these viruses is a single messenger-active (+)-RNA of 7200–8500 nt. Besides coding for the viral proteins, it also contains functionally important RNA secondary structures, among them an internal ribosomal entry site (IRES) region towards the 5′-end. This contribution provides a comprehensive computational survey of the complete genomic RNAs and a detailed comparative analysis of the conserved structural elements in seven of the currently nine genera in the family Picornaviridae. Compared with previous studies we find: (i) that only smaller sections of the IRES region than previously reported are conserved at single base-pair resolution and (ii) that there is a number of significant structural elements in the coding region. Furthermore, we identify potential cis-acting replication elements in four genera where this feature has not been reported so far.

Complete Nucleotide Sequence and Genetic Organization of Aichi Virus, a Distinct Member of the Picornaviridae Associated with Acute Gastroenteritis in Humans

Yamashita, Teruo; Sakae, Kenji; Tsuzuki, Hideaki; Suzuki, Yasumoto; Ishikawa, Naohisa; Takeda, Naokazu; Miyamura, Tatsuo; Yamazaki, Shudo
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /10/1998 EN
Relevância na Pesquisa
27.02%
The complete nucleotide sequence of a novel enteric virus, Aichi virus, associated with nonbacterial acute gastroenteritis in humans was determined. The Aichi virus genome proved to be a single-stranded positive-sense RNA molecule with 8,251 bases excluding a poly(A) tail; it contains a large open reading frame with 7,302 nucleotides that encodes a potential polyprotein precursor of 2,433 amino acids. The genome contains a 5′ nontranslated region (NTR) with 712 bases and a 3′ NTR with 240 bases followed by a poly(A) tail. The structure of the genome, VPg–5′ NTR–leader protein–structural proteins–nonstructural proteins–3′ NTR–poly(A), was found to be typical of a picornavirus. The VP0-VP3 and VP3-VP1 cleavage sites were determined to be Q-H and Q-T, respectively, by N-terminal amino acid sequence analyses using purified virion proteins. Possible cleavage sites, Q-G, Q-A, and Q-S, which cleave P2 and P3 polyproteins were found to be similar to those of picornaviruses. A dendrogram based on 3Dpol proteins indicated that Aichi virus is genetically distinct from the known six genera of picornaviruses including entero-, rhino-, cardio-, aphtho-, and hepatovirus and echovirus 22. Considering this together with other properties of the virus (T. Yamashita...

Construction of an Infectious cDNA Clone of Aichi Virus (a New Member of the Family Picornaviridae) and Mutational Analysis of a Stem-Loop Structure at the 5′ End of the Genome

Sasaki, Jun; Kusuhara, Yasuhiro; Maeno, Yoshimasa; Kobayashi, Nobumichi; Yamashita, Teruo; Sakae, Kenji; Takeda, Naokazu; Taniguchi, Koki
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /09/2001 EN
Relevância na Pesquisa
27.02%
Aichi virus is the type species of a new genus, Kobuvirus, of the family Picornaviridae. In this study, we constructed a full-length cDNA clone of Aichi virus whose in vitro transcripts were infectious to Vero cells. During construction of the infectious cDNA clone, a novel sequence of 32 nucleotides was identified at the 5′ end of the genome. Computer-assisted prediction of the secondary structure of the 5′ end of the genome, including the novel sequence, suggested the formation of a stable stem-loop structure consisting of 42 nucleotides. The function of this stem-loop in virus replication was investigated using various site-directed mutants derived from the infectious cDNA clone. Our data indicated that correct folding of the stem-loop at the 5′ end of the positive strand, but not at the 3′ end of the negative strand, is critical for viral RNA replication. The primary sequence in the lower part of the stem was also suggested to be crucial for RNA replication. In contrast, nucleotide changes in the loop segment did not so severely reduce the efficiency of virus replication. A double mutant, in which both nucleotide stretches of the middle part of the stem were replaced by their complementary nucleotides, had efficient RNA replication and translation abilities but was unable to produce viruses. These results indicate that the stem-loop at the 5′ end of the Aichi virus genome is an element involved in both viral RNA replication and production of infectious virus particles.

Amplicon Sequencing and Improved Detection of Human Rhinovirus in Respiratory Samples

Deffernez, Christelle; Wunderli, Werner; Thomas, Yves; Yerly, Sabine; Perrin, Luc; Kaiser, Laurent
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /07/2004 EN
Relevância na Pesquisa
17.31%
Improved knowledge of the genotypic characteristics of human rhinovirus (HRV) is required, as are nucleic detection assays with the capacity to overcome both the similarities between members of the family Picornaviridae and the wide diversity of different HRV serotypes. The goal of the present study was to investigate the variability and the genotypic diversity of clinical strains circulating in the community. Since most reverse transcription (RT)-PCR assays available cannot differentiate HRV from other members of the family Picornaviridae, we also validated an assay specific for HRV detection. The 5′ noncoding regions of 87 different HRV serotypes and clinical isolates were sequenced. On the basis of sequence analysis and phylogenetic determination, we first confirmed that all clinical isolates were HRV. We then validated a real-time RT-PCR assay that was able not only to detect all HRV serotypes and all clinical isolates tested but also to accurately discriminate between rhinovirus and other viruses from the family Picornaviridae. This assay was negative with isolates of coxsackievirus (types A and B), echovirus, enterovirus, parechovirus, and poliovirus, as well as nonpicornaviruses. Among a series of bronchoalveolar lavage specimens...

Detection of genome-scale ordered RNA structure (GORS) in genomes of positive-stranded RNA viruses: Implications for virus evolution and host persistence

SIMMONDS, PETER; TUPLIN, ANDREW; EVANS, DAVID J.
Fonte: Copyright 2004 by RNA Society Publicador: Copyright 2004 by RNA Society
Tipo: Artigo de Revista Científica
Publicado em /09/2004 EN
Relevância na Pesquisa
17.02%
Discrete RNA secondary and higher-order structures, typically local in extent, play a fundamental role in RNA virus replication. Using new bioinformatics analysis methods, we have identified genome-scale ordered RNA structure (GORS) in many genera and families of positive-strand animal and plant RNA viruses. There was remarkably variability between genera that possess this characteristic; for example, hepaciviruses in the family Flaviviridae show evidence for extensive internal base-pairing throughout their coding sequences that was absent in both the related pestivirus and flavivirus genera. Similar genus-associated variability was observed in the Picornaviridae, the Caliciviridae, and many plant virus families. The similarity in replication strategies between genera in each of these families rules out a role for GORS in a fundamentally conserved aspect of this aspect of the virus life cycle. However, in the Picornaviridae, Flaviviridae, and Caliciviridae, the existence of GORS correlated strongly with the ability of each genus to persist in their natural hosts. This raises the intriguing possibility of a role for GORS in the modulation of innate intracellular defense mechanisms (and secondarily, the acquired immune system) triggered by double-stranded RNA...

A highly prevalent and genetically diversified Picornaviridae genus in South Asian children

Kapoor, Amit; Victoria, Joseph; Simmonds, Peter; Slikas, Elizabeth; Chieochansin, Thaweesak; Naeem, Asif; Shaukat, Shahzad; Sharif, Salmaan; Alam, Muhammad Masroor; Angez, Mehar; Wang, Chunlin; Shafer, Robert W.; Zaidi, Sohail; Delwart, Eric
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
EN
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27.02%
Viral metagenomics focused on particle-protected nucleic acids was used on the stools of South Asian children with nonpolio acute flaccid paralysis (AFP). We identified sequences distantly related to Seneca Valley virus and cardioviruses that were then used as genetic footholds to characterize multiple viral species within a previously unreported genus of the Picornaviridae family. The picornaviruses were detected in the stools of >40% of AFP and healthy Pakistani children. A genetically diverse and highly prevalent enteric viral infection, characteristics similar to the Enterovirus genus, was therefore identified substantially expanding the genetic diversity of the RNA viral flora commonly found in children.

Metagenomic Analyses of Viruses in Stool Samples from Children with Acute Flaccid Paralysis▿

Victoria, Joseph G.; Kapoor, Amit; Li, Linlin; Blinkova, Olga; Slikas, Beth; Wang, Chunlin; Naeem, Asif; Zaidi, Sohail; Delwart, Eric
Fonte: American Society for Microbiology (ASM) Publicador: American Society for Microbiology (ASM)
Tipo: Artigo de Revista Científica
EN
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17.02%
We analyzed viral nucleic acids in stool samples collected from 35 South Asian children with nonpolio acute flaccid paralysis (AFP). Sequence-independent reverse transcription and PCR amplification of capsid-protected, nuclease-resistant viral nucleic acids were followed by DNA sequencing and sequence similarity searches. Limited Sanger sequencing (35 to 240 subclones per sample) identified an average of 1.4 distinct eukaryotic viruses per sample, while pyrosequencing yielded 2.6 viruses per sample. In addition to bacteriophage and plant viruses, we detected known enteric viruses, including rotavirus, adenovirus, picobirnavirus, and human enterovirus species A (HEV-A) to HEV-C, as well as numerous other members of the Picornaviridae family, including parechovirus, Aichi virus, rhinovirus, and human cardiovirus. The viruses with the most divergent sequences relative to those of previously reported viruses included members of a novel Picornaviridae genus and four new viral species (members of the Dicistroviridae, Nodaviridae, and Circoviridae families and the Bocavirus genus). Samples from six healthy contacts of AFP patients were similarly analyzed and also contained numerous viruses, particularly HEV-C, including a potentially novel Enterovirus genotype. Determining the prevalences and pathogenicities of the novel genotypes...

Molecular characterization of a novel Ljungan virus (Parechovirus; Picornaviridae) reveals a fourth genotype and indicates ancestral recombination

Tolf, Conny; Gullberg, Maria; Johansson, E. Susanne; Tesh, Robert B.; Andersson, Björn; Lindberg, A. Michael
Fonte: Society for General Microbiology Publicador: Society for General Microbiology
Tipo: Artigo de Revista Científica
Publicado em /04/2009 EN
Relevância na Pesquisa
27.02%
Ljungan virus (LV) was discovered 20 years ago in Swedish bank voles (Myodes glareolus, previously referred to as Clethrionomys glareolus) during the search for an infectious agent causing lethal myocarditis in young athletes. To date, the genomes of four LV isolates, including the prototype 87-012 strain, have been characterized. Three of these LV strains were isolated from bank voles trapped in Sweden. Sequence analysis of an American virus (M1146), isolated from a montane vole (Microtus montanus) in western USA, indicates that this strain represents a genotype that is different from the Swedish strains. Here, we present genomic analyses of a fifth LV strain (64-7855) isolated from a southern red-backed vole (Myodes gapperi) trapped during arbovirus studies in New York state in the north-eastern USA in the 1960s. Sequence analysis of the 64-7855 genome showed an LV-like genome organization and sequence similarity to other LV strains. Genetic and phylogenetic analyses of the evolutionary relationship between the 64-7855 strain and other viruses within the family Picornaviridae, including previously published LV strains, demonstrated that the 64-7855 strain constitutes a new genotype within the LV species. Analyses also showed that different regions of the 64-7855 genome have different phylogenetic relationships with other LV strains...

The Fecal Viral Flora of Wild Rodents

Phan, Tung G.; Kapusinszky, Beatrix; Wang, Chunlin; Rose, Robert K.; Lipton, Howard L.; Delwart, Eric L.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
17.02%
The frequent interactions of rodents with humans make them a common source of zoonotic infections. To obtain an initial unbiased measure of the viral diversity in the enteric tract of wild rodents we sequenced partially purified, randomly amplified viral RNA and DNA in the feces of 105 wild rodents (mouse, vole, and rat) collected in California and Virginia. We identified in decreasing frequency sequences related to the mammalian viruses families Circoviridae, Picobirnaviridae, Picornaviridae, Astroviridae, Parvoviridae, Papillomaviridae, Adenoviridae, and Coronaviridae. Seventeen small circular DNA genomes containing one or two replicase genes distantly related to the Circoviridae representing several potentially new viral families were characterized. In the Picornaviridae family two new candidate genera as well as a close genetic relative of the human pathogen Aichi virus were characterized. Fragments of the first mouse sapelovirus and picobirnaviruses were identified and the first murine astrovirus genome was characterized. A mouse papillomavirus genome and fragments of a novel adenovirus and adenovirus-associated virus were also sequenced. The next largest fraction of the rodent fecal virome was related to insect viruses of the Densoviridae...

Complete Genome Analysis of Three Novel Picornaviruses from Diverse Bat Species▿

Lau, Susanna K. P.; Woo, Patrick C. Y.; Lai, Kenneth K. Y.; Huang, Yi; Yip, Cyril C. Y.; Shek, Chung-Tong; Lee, Paul; Lam, Carol S. F.; Chan, Kwok-Hung; Yuen, Kwok-Yung
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /09/2011 EN
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17.31%
Although bats are important reservoirs of diverse viruses that can cause human epidemics, little is known about the presence of picornaviruses in these flying mammals. Among 1,108 bats of 18 species studied, three novel picornaviruses (groups 1, 2, and 3) were identified from alimentary specimens of 12 bats from five species and four genera. Two complete genomes, each from the three picornaviruses, were sequenced. Phylogenetic analysis showed that they fell into three distinct clusters in the Picornaviridae family, with low homologies to known picornaviruses, especially in leader and 2A proteins. Moreover, group 1 and 2 viruses are more closely related to each other than to group 3 viruses, which exhibit genome features distinct from those of the former two virus groups. In particular, the group 3 virus genome contains the shortest leader protein within Picornaviridae, a putative type I internal ribosome entry site (IRES) in the 5′-untranslated region instead of the type IV IRES found in group 1 and 2 viruses, one instead of two GXCG motifs in 2A, an L→V substitution in the DDLXQ motif in 2C helicase, and a conserved GXH motif in 3C protease. Group 1 and 2 viruses are unique among picornaviruses in having AMH instead of the GXH motif in 3Cpro. These findings suggest that the three picornaviruses belong to two novel genera in the Picornaviridae family. This report describes the discovery and complete genome analysis of three picornaviruses in bats...

A Member of a New Picornaviridae Genus Is Shed in Pig Feces

Sauvage, Virginie; Ar Gouilh, Meriadeg; Cheval, Justine; Muth, Erika; Pariente, Kevin; Burguiere, Ana; Caro, Valérie; Manuguerra, Jean-Claude; Eloit, Marc
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /09/2012 EN
Relevância na Pesquisa
27.02%
During a study of the fecal microbiomes from two healthy piglets using high-throughput sequencing (HTS), we identified a viral genome containing an open reading frame encoding a predicted polyprotein of 2,133 amino acids. This novel viral genome displayed the typical organization of picornaviruses, containing three structural proteins (VP0, VP3, and VP1), followed by seven nonstructural proteins (2A, 2B, 2C, 3A, 3B, 3Cpro, and 3Dpol). Given its particular relationship with Parechovirus, we propose to name it “Pasivirus” for Parecho sister clade virus, with “Swine pasivirus 1” (SPaV1) as the type species. Fecal samples collected at an industrial farm from healthy sows and piglets from the same herd (25 and 75, respectively) with ages ranging from 4 to 28 weeks were analyzed for the presence of SPaV1 by one-step reverse transcription (RT)-PCR targeting a 3D region of 151 bp. SPaV1 was detected in fecal samples from 51/75 healthy piglets (68% of the animals) and in none of the 25 fecal samples from healthy sows, indicating that SPaV1 circulates through enteric infection of healthy piglets. We propose that SPaV1 represents the first member of a novel Picornaviridae genus related to parechoviruses.

Two Closely Related Novel Picornaviruses in Cattle and Sheep in Hungary from 2008 to 2009, Proposed as Members of a New Genus in the Family Picornaviridae

Reuter, Gábor; Pankovics, Péter; Knowles, Nick J.; Boros, Ákos
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /12/2012 EN
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Two novel picornaviruses were serendipitously identified in apparently healthy young domestic animals—cattle (Bos taurus) and, subsequently, sheep (Ovis aries)—in Hungary during 2008 and 2009. Complete genome sequencing and comparative analysis showed that the two viruses are related to each other and have identical genome organizations, VPg + 5′ UTRIRES-II[L/1A-1B-1C-1D-2ANPG↓P/2B-2C/3A-3BVPg-3Cpro-3Dpol] 3′ UTR-poly(A). We suggest that they form two novel viral genotypes/serotypes, bovine hungarovirus 1 (BHuV-1; GenBank accession number JQ941880) and ovine hungarovirus 1 (OHuV-1; GenBank accession number HM153767), which may belong to a potential novel picornavirus genus in the family Picornaviridae. The genome lengths of BHuV-1 and OHuV-1 are 7,583 and 7,588 nucleotides, each comprising a single open reading frame encoding 2,243 and 2,252 amino acids, respectively. In the 5′ untranslated regions (5′ UTRs), both hungaroviruses are predicted to have a type II internal ribosome entry site (IRES). The nucleotide sequence and the secondary RNA structure of the hungarovirus IRES core domains H-I-J-K-L are highly similar to that of human parechovirus (HPeV) (genus Parechovirus), especially HPeV-3. However, in the polyprotein coding region...

Comparative Complete Genome Analysis of Chicken and Turkey Megriviruses (Family Picornaviridae): Long 3′ Untranslated Regions with a Potential Second Open Reading Frame and Evidence for Possible Recombination

Boros, Ákos; Pankovics, Péter; Knowles, Nick J.; Nemes, Csaba; Delwart, Eric; Reuter, Gábor
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /06/2014 EN
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Members of the family Picornaviridae consist of small positive-sense single-stranded RNA (+ssRNA) viruses capable of infecting various vertebrate species, including birds. One of the recently identified avian picornaviruses, with a remarkably long (>9,040-nucleotide) but still incompletely sequenced genome, is turkey hepatitis virus 1 (THV-1; species Melegrivirus A, genus Megrivirus), a virus associated with liver necrosis and enteritis in commercial turkeys (Meleagris gallopavo). This report presents the results of the genetic analysis of three complete genomes of megriviruses from fecal samples of chickens (chicken/B21-CHV/2012/HUN, GenBank accession no. KF961186, and chicken/CHK-IV-CHV/2013/HUN, GenBank accession no. KF961187) (Gallus gallus domesticus) and turkey (turkey/B407-THV/2011/HUN, GenBank accession no. KF961188) (Meleagris gallopavo) with the largest picornavirus genome (up to 9,739 nucleotides) so far described. The close phylogenetic relationship to THV-1 in the nonstructural protein-coding genome region and possession of the same internal ribosomal entry site type (IVB-like) suggest that the study strains belong to the genus Megrivirus. However, the genome comparisons revealed numerous unique variations (e.g., different numbers of potential 2A peptides...

Rosavirus: the prototype of a proposed new genus of the Picornaviridae family

Phan, Tung Gia; Vo, Nguyen Phung; Simmonds, Peter; Samayoa, Erik; Naccache, Samia; Chiu, Charles Y.; Delwart, Eric
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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We describe a 8,724-nucleotide-long picornavirus genome encoding a single 2,470-aa polyprotein obtained from the feces of a wild mouse. Rosavirus is genetically closest to the double ORF Dicipivirus found in canine feces that is currently the only picornavirus with a second internal ribosome entry site (IRES). Of note, a section of rosavirus’ 5′UTR showed strong sequence and structural conservation with the type II IRES from the Parechovirus and Hungarovirus genera possibly reflecting exchange of genetic modules between genera. Based on genetic distance criteria rosavirus qualifies as prototype of a new genus of the Picornaviridae family.

Estudo morfol?gico e imunol?gico da encefalite induzida pelo v?rus jurua?? em modelo murino

FERREIRA, Natalie Chaves
Fonte: Universidade Federal do Pará Publicador: Universidade Federal do Pará
Tipo: Dissertação de Mestrado
POR
Relevância na Pesquisa
27.61%
Muitos estudos t?m sido realizados para o entendimento da neuropatog?nese das encefalites virais a partir de trabalhos experimentais, por?m, nenhum estudo experimental foi dedicado ? compreens?o da neuropatog?nese de membros da fam?lia Picornaviridae isolados de morcegos na regi?o amaz?nica. O v?rus Jurua??, um desses agentes, parcialmente caracterizado como membro da fam?lia Picornaviridae por Ara?jo e colaboradores (2006), causou les?es no enc?falo de camundongos neonatos com presen?a de gliose reativa, apesar de n?o provocar efeito citop?tico (ECP) em cultivos prim?rios de c?lulas do sistema nervoso central (SNC), sugerindo que este agente viral seja respons?vel pela morte dos animais devido a uma intensa resposta imune. O objetivo desse trabalho foi investigar a resposta imune no SNC e altera??es celulares causadas pelo v?rus Jurua?? em camundongos albinos da linhagem BALB/c neonatos a partir de an?lises histopatol?gicas, de ativa??o microglial e da express?o de citocinas, ?xido n?trico (NO) e esp?cies reativas de oxig?nio (ROS). Para tanto, foram realizados processamento de amostras para histopatologia, ensaios imunoenzim?ticos, imunohistoqu?micos e de imunofluoresc?ncia, al?m de testes para quantifica??o de NO e ROS e an?lises estat?sticas. Nossos resultados demonstraram que o v?rus Jurua?? induz les?es por todo o enc?falo...

In vitro antiviral activity of the anthraquinone chrysophanic acid against poliovirus

Semple, S.; Pyke, S.; Reynolds, G.; Flower, R.
Fonte: Elsevier Science BV Publicador: Elsevier Science BV
Tipo: Artigo de Revista Científica
Publicado em //2001 EN
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27.31%
Chrysophanic acid (1,8-dihydroxy-3-methylanthraquinone), isolated from the Australian Aboriginal medicinal plant Dianella longifolia, has been found to inhibit the replication of poliovirus types 2 and 3 (Picornaviridae) in vitro. The compound inhibited poliovirus-induced cytopathic effects in BGM (Buffalo green monkey) kidney cells at a 50% effective concentration of 0.21 and 0.02 μg/ml for poliovirus types 2 and 3, respectively. The compound inhibited an early stage in the viral replication cycle, but did not have an irreversible virucidal effect on poliovirus particles. Chrysophanic acid did not have significant antiviral activity against five other viruses tested: Coxsackievirus types A21 and B4, human rhinovirus type 2 (Picornaviridae), and the enveloped viruses Ross River virus (Togaviridae) and herpes simplex virus type 1 (Herpesviridae). Four structurally-related anthraquinones — rhein, 1,8-dihydroxyanthraquinone, emodin and aloe-emodin were also tested for activity against poliovirus type 3. None of the four compounds was as active as chrysophanic acid against the virus. The results suggested that two hydrophobic positions on the chrysophanic acid molecule (C-6 and the methyl group attached to C-3) were important for the compound's activity against poliovirus.; http://www.elsevier.com/wps/find/journaldescription.cws_home/521852/description#description; Susan J. Semple...

A Distinct Class of Internal Ribosomal Entry Site in Members of the Kobuvirus and Proposed Salivirus and Paraturdivirus Genera of the Picornaviridae

Sweeney, Trevor R.; Dhote, Vidya; Yu, Yingpu; Hellen, Christopher U. T.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /02/2012 EN
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The 5′-untranslated regions (5′ UTRs) of picornavirus genomes contain an internal ribosomal entry site (IRES) that promotes the end-independent initiation of translation. Picornavirus IRESs are classified into four structurally distinct groups, each with different initiation factor requirements. Here, we identify a fifth IRES class in members of Kobuvirus, Salivirus, and Paraturdivirus genera of Picornaviridae: Aichi virus (AV), bovine kobuvirus (BKV), canine kobuvirus (CKoV), mouse kobuvirus (MKoV), sheep kobuvirus (SKV), salivirus A (SV-A), turdivirus 2 (TV2), and TV3. The 410-nucleotide (nt)-long AV IRES comprises four domains (I to L), including a hairpin (L) that overlaps a Yn-Xm-AUG (pyrimidine tract/spacer/initiation codon) motif. SV-A, CKoV, and MKoV also contain these four domains, whereas BKV, SKV, and TV2/TV3 5′ UTRs contain domains that are related to domain I and equivalent to domains J and K but lack an AV-like domain L. These IRESs are located at different relative positions between a conserved 5′-terminal origin of replication and divergent coding sequences. Elements in these IRESs also occur elsewhere: domain J's apical subdomain, which contains a GNRA tetraloop, matches an element in type 1 IRESs, and eIF4G-binding motifs in domain K and in type 2 IRESs are identical. Other elements are unique...