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1.
J Gen Virol ; 100(1): 5-6, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30484762

RESUMO

Birnaviridae is a family of viruses with bi-segmented dsRNA genomes totalling about 6 kbp forming icosahedral, non-enveloped virions. The family includes four genera, members of three of which (Aquabirnavirus, Avibirnavirus and Blosnavirus) infect vertebrates (excluding mammals), whereas members of the fourth genus (Entomobirnavirus) infect insects. Each genus includes 1-3 species. Infectious pancreatic necrosis virus of salmonids and infectious bursal disease virus of poultry are two economically important birnaviruses. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of Birnaviridae, which is available at www.ictv.global/report/birnaviridae.


Assuntos
Birnaviridae/classificação , RNA Viral/genética , Vírion/ultraestrutura , Animais , Birnaviridae/genética , Birnaviridae/isolamento & purificação , Birnaviridae/ultraestrutura , Insetos/virologia , Vertebrados/virologia
2.
Avian Pathol ; 46(1): 68-75, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27400318

RESUMO

Increasing evidence suggests that a new birnavirus, named chicken proventricular necrosis virus (CPNV), is the aetiological agent of transmissible viral proventriculitis (TVP). The present work aimed to explore the possible presence of both TVP and CPNV in the UK. Forty-four chickens showing TVP-compatible gross lesions were classified into three groups based on the histological lesions: (i) TVP-affected chickens: lymphocytic infiltration and glandular necrosis (n = 15); (ii) lymphocytic proventriculitis (LP)-affected chickens: lymphocytic infiltration without necrosis (n = 18); and (iii) without proventriculitis (WP): no lymphocytic infiltration or necrosis (n = 11). Nine proventriculi (seven out of 15 corresponding to TVP, and two out of 11 corresponding to LP) were positive for CPNV by reverse transcriptase polymerase chain reaction (RT-PCR). These results support the previously suggested idea of CPNV as causative agent of TVP. Moreover, these data show that CPNV can also be detected in a number of cases with LP, which do not fulfil the histological TVP criteria. Phylogenetic analysis of partial sequences of gene VP1 showed that British CPNV sequences were closer to other European CPNV sequences and might constitute a different lineage from the American CPNV. TVP cases with negative CPNV PCR results may be due to chronic stages of the disease or to the reduced PCR sensitivity on formalin-fixed paraffin-embedded tissues. However, involvement of other agents in some of the cases cannot totally be ruled out. As far as the authors are aware, this is the first peer-reviewed report of TVP as well as of CPNV in the UK, and the first exploratory CPNV phylogenetic study.


Assuntos
Infecções por Birnaviridae/veterinária , Birnaviridae/isolamento & purificação , Galinhas/virologia , Doenças das Aves Domésticas/virologia , Animais , Birnaviridae/classificação , Birnaviridae/genética , Infecções por Birnaviridae/diagnóstico , Infecções por Birnaviridae/patologia , Infecções por Birnaviridae/virologia , Necrose/veterinária , Filogenia , Doenças das Aves Domésticas/patologia , Estudos Prospectivos , Proventrículo/patologia , Proventrículo/virologia , Análise de Sequência de RNA/veterinária , Reino Unido/epidemiologia
3.
Avian Dis ; 59(3): 384-7, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26478156

RESUMO

This report describes an outbreak of transmissible viral proventriculitis (TVP) associated with runting stunting syndrome (RSS) in 25- and 28-day-old broiler chickens, in which chicken proventricular necrosis virus (CNPV) was detected. Clinical signs included poor uniformity, very small birds for their age, increased mortality, and culling of smaller birds. Almost all birds necropsied exhibited moderate to severely enlarged proventriculi with diffusely pale serosa and thickened walls. Microscopically the proventriculi had lesions of degeneration and necrosis of the epithelium of the proventricular glands, accompanied by lymphocytic inflammation and glandular hyperplasia, with occasional formation of lymphoid nodules within the glandular parenchyma. Immunohistochemistry staining for CPNV was positive. Positive staining was generally found in the cytoplasm of glandular epithelial cells in the form of finely granular brown pigment. CPNV RNA was detected in the proventriculi by reverse transcriptase-PCR (RT-PCR). Other findings included mild enteritis in a few birds and small bursa of Fabricius. Direct electron microscopy performed on the intestinal samples was negative for viral particles. RT-PCR analysis of bursae was positive for infectious bursal disease virus (IBDV). In conclusion, this report associates TVP with RSS by describing an outbreak in which TVP attributable to CPNV was the most commonly found lesionin chickens with a clinical history compatible with RSS. Therefore, TVP should be considered as a possible differential diagnosis in cases compatible with RSS.


Assuntos
Infecções por Birnaviridae/veterinária , Birnaviridae/isolamento & purificação , Galinhas , Doenças das Aves Domésticas/virologia , Proventrículo/patologia , Gastropatias/veterinária , Animais , Birnaviridae/classificação , Infecções por Birnaviridae/patologia , Infecções por Birnaviridae/virologia , Proventrículo/virologia , Gastropatias/patologia , Gastropatias/virologia , Ganho de Peso
4.
Dis Aquat Organ ; 114(2): 117-25, 2015 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-25993886

RESUMO

In November 2010, a rainbow trout (Oncorhynchus mykiss) hatchery in Victoria reported increased mortality rates in diploid and triploid female fingerlings. Live and moribund fish were submitted for laboratory investigation. All fish showed hyperpigmentation of the cranial half of the body. Histological lesions were seen in all areas of skin examined despite the localised nature of the gross lesions. There was irregular hyperplasia and spongiosis, alternating with areas of thinning and architectural disturbance. Occasionally, particularly in superficial layers of epithelium, cells showed large, eosinophilic inclusions that obscured other cellular detail. A small number of fish had necrosis in dermis, subcutis and superficial muscles. Bacteriological culture of skin and gills was negative for all bacterial pathogens, including Flavibacterium columnare, the agent of columnaris disease. Attempts at virus isolation from the skin of affected fish resulted in the development of a cytopathic effect in RTG-2 cell cultures suggestive of the presence of a virus. Negative contrast electron microscopy of cell culture supernatant demonstrated the presence of viral particles with the typical morphology of birnaviruses. Preliminary molecular characterisation identified an aquabirnavirus that differed from both the Tasmanian aquabirnavirus (TABV) and other aquabirnaviruses exotic to Australia. Previous isolates of aquabirnaviruses in Australia and New Zealand have been from healthy fish in a marine environment. This is the first report of an aquabirnavirus isolated from young salmonids at a freshwater hatchery in Australia. The role of the virus in the mortality event on the farm is uncertain as no further deaths attributable to this virus have occurred in the 4 yr since its initial discovery. The virus has been provisionally named Victorian trout aquabirnavirus (VTAB).


Assuntos
Infecções por Birnaviridae/veterinária , Birnaviridae/classificação , Birnaviridae/isolamento & purificação , Doenças dos Peixes/virologia , Oncorhynchus mykiss/virologia , Animais , Aquicultura , Austrália/epidemiologia , Birnaviridae/genética , Infecções por Birnaviridae/epidemiologia , Infecções por Birnaviridae/virologia , Feminino , Doenças dos Peixes/epidemiologia , Filogenia
5.
J Virol ; 86(5): 2390-9, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22171264

RESUMO

Espirito Santo virus (ESV) is a newly discovered virus recovered as contamination in a sample of a virulent strain of dengue-2 virus (strain 44/2), which was recovered from a patient in the state of Espirito Santo, Brazil, and amplified in insect cells. ESV was found to be dependent upon coinfection with a virulent strain of dengue-2 virus and to replicate in C6/36 insect cells but not in mammalian Vero cells. A sequence of the genome has been produced by de novo assembly and was not found to match to any known viral sequence. An incomplete match to the nucleotide sequence of the RNA-dependent RNA polymerase from Drosophila X virus (DXV), another birnavirus, could be detected. Mass spectrometry analysis of ESV proteins found no matches in the protein data banks. However, peptides recovered by mass spectrometry corresponded to the de novo-assembled sequence by BLAST analysis. The composition and three-dimensional structure of ESV are presented, and its sequence is compared to those of other members of the birnavirus family. Although the virus was found to belong to the family Birnaviridae, biochemical and sequence information for ESV differed from that of DXV, the representative species of the genus Entomobirnavirus. Thus, significant differences underscore the uniqueness of this infectious agent, and its relationship to the coinfecting virus is discussed.


Assuntos
Infecções por Birnaviridae/virologia , Birnaviridae/isolamento & purificação , Birnaviridae/fisiologia , Replicação Viral , Aedes , Sequência de Aminoácidos , Animais , Birnaviridae/classificação , Birnaviridae/genética , Linhagem Celular , Genoma Viral , Humanos , Dados de Sequência Molecular , Filogenia , Alinhamento de Sequência , Proteínas Virais/química , Proteínas Virais/genética , Cultura de Vírus
6.
Avian Dis ; 55(1): 2-7, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21500628

RESUMO

Chicken proventricular necrosis virus (CPNV), isolate R11/3, previously was isolated from transmissible viral proventriculitis-affected chickens and was determined to be the likely etiology of this disease. CPNV was identified as a birnavirus on the basis of virion size and morphology (icosahedral, approximately 75 nm in diameter, nonenveloped); buoyant density in cesium chloride (1.32 g/ml); a genome comprising bisegmented, double-stranded RNA (approximately 3.8 and 3.4 kilobase pairs); and nucleotide sequence analyses. Nucleotide sequencing of CPNV RNA, segment B, identified a single large open reading frame that encodes a 903-amino acid protein. The 903-amino acid protein was identified as the putative VP1, the viral RNA-dependent RNA polymerase (RdRp), on the basis of sequence homologies with other birnavirus VP1 proteins. The CPNV VP1 possessed the unique permuted RdRp sequence motif arrangement characteristic of birnaviruses; however, phylogenetic analyses based on VP1 demonstrated that CPNV is deeply divergent from other birnaviruses.


Assuntos
Infecções por Birnaviridae/veterinária , Birnaviridae/classificação , Birnaviridae/genética , Galinhas , Genoma Viral , Doenças das Aves Domésticas/virologia , Sequência de Aminoácidos , Animais , Infecções por Birnaviridae/virologia , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/metabolismo , Clonagem Molecular , Genes Virais , Dados de Sequência Molecular , Filogenia , RNA Viral/genética
7.
Dis Aquat Organ ; 93(1): 1-15, 2010 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-21290892

RESUMO

An aquatic birnavirus, first isolated in Australia from farmed Atlantic salmon in Tasmania in 1998, has continued to be re-isolated on an infrequent but regular basis. Due to its low pathogenicity, there has been little urgency to undertake a comprehensive characterisation of this aquatic birnavirus. However, faced with possible incursions of any new aquatic birnaviruses, specific identification and differentiation of this virus from other, pathogenic, aquatic birnaviruses such as infectious pancreatic necrosis virus (IPNV) are becoming increasingly important. The present study determined the nucleic acid sequence of the aquatic birnavirus originally isolated in 1998, as well as a subsequent isolate from 2002. The sequences of the VP2 and VP5 genes were compared to that of other aquatic birnaviruses, including non-pathogenic aquatic birnavirus isolates from New Zealand and pathogenic infectious pancreatic necrosis virus isolates from North America and Europe. The deduced amino acid (aa) sequences indicate that the Australian and New Zealand isolates fall within Genogroup 5 together with IPNV strains Sp, DPL, Fr10 and N1. Thus, Genogroup 5 appears to contain aquatic birnavirus isolates from quite diverse host and geographical ranges. Using the sequence information derived from this study, a simple diagnostic test has been developed that differentiates the current Australian isolates from all other aquatic birnaviruses, including the closely related isolates from New Zealand.


Assuntos
Infecções por Birnaviridae/veterinária , Birnaviridae/classificação , Birnaviridae/genética , Doenças dos Peixes/virologia , Sequência de Aminoácidos , Animais , Australásia/epidemiologia , Infecções por Birnaviridae/epidemiologia , Infecções por Birnaviridae/virologia , Proteínas do Capsídeo/genética , Regulação Viral da Expressão Gênica/fisiologia , Dados de Sequência Molecular , Filogenia , Salmão
8.
J Gen Virol ; 89(Pt 12): 3156-64, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19008406

RESUMO

Birnaviruses are bi-segmented double-stranded RNA (dsRNA) viruses infecting insects, avian species and a wide range of aquatic species. Although homologous recombination is a common phenomenon in positive-sense RNA viruses, recombination in dsRNA viruses is rarely reported. Here we performed a comprehensive survey on homologous recombination in all available sequences (>1800) of the family Birnaviridae based on phylogenetic incongruence. Although inter-species recombination was not evident, potential intra-species recombination events were detected in aquabirnaviruses and infectious bursal disease virus (IBDV). Eight potential recombination events were identified and the possibility that these events were non-naturally occurring was assessed case by case. Five of the eight events were identified in IBDVs and all of these five events involved live attenuated vaccine strains. This finding suggests that homologous recombination between vaccine and wild-type IBDV strains may have occurred; the potential risk of mass vaccination using live vaccines is discussed. This is the first report of evidence for homologous recombination within the family Birnaviridae.


Assuntos
Birnaviridae/classificação , Birnaviridae/genética , Filogenia , Recombinação Genética , Sequência de Aminoácidos , Animais , Aquabirnavirus/classificação , Aquabirnavirus/genética , Bases de Dados Genéticas , Vírus da Doença Infecciosa da Bursa/classificação , Vírus da Doença Infecciosa da Bursa/genética , RNA Replicase/genética , Alinhamento de Sequência , Análise de Sequência de DNA , Especificidade da Espécie , Vacinas Atenuadas , Proteínas Estruturais Virais/genética , Vacinas Virais
9.
J Vet Sci ; 9(1): 85-90, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18296892

RESUMO

The cDNA nucleotide sequence of genome segment B encoding the VP1 protein was determined for the aquatic birnavirus GC1 isolated from the rockfish Sebastes schlegeli in Korea. The VP1 protein of GC1 contains a 2,538 bp open reading frame, which encodes a protein comprising 846 amino acid residues that has a predicted MW of 94 kDa. The sequence contains 6 potential Asn-X-Ser/Thr motifs. Eight potential Ser phosphorylation sites and 1 potential Tyr phophorylation site were also identified. GC1 contains the Leu-Lys-Asn (LKN) motif instead of the typical Gly-Asp-Asp (GDD) motif found in other aquatic birnaviruses. We also identified the GLPYIGKT motif, the putative GTPbinding site at amino acid position 248. In total, the VP1 regions of 22 birnavirus strains were compared for analyzing the genetic relationship among the family Birnaviridae. Based on the deduced amino acid sequences, GC1 was observed to be more closely related to the infectious pancreatic necrosis virus (IPNV) from the USA, Japan, and Korea than the IPNV from Europe. Further, aquatic birnaviruses containing GC1 and IPNV have genogroups that are distinct from those in the genus Avibirnaviruses and Entomo-birnaviruses. The birnavirusstrains were clustered into 5 genogroups based on their amino acid sequences. The marine aquatic birnaviruses (MABVs) containing GC1 were included in the MABV genogroup; the IPNV strains isolated from Korea, Japan, and the USA were included in genogroup 1 and the IPNV strains isolated primarily from Europe were included in genogroup 2. Avibirnaviruses and entomobirnaviruses were included in genogroup 3 and 4, respectively.


Assuntos
Birnaviridae/genética , Proteínas do Capsídeo/genética , Peixes/virologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Birnaviridae/classificação , Proteínas do Capsídeo/química , Linhagem Celular , Coreia (Geográfico) , Dados de Sequência Molecular , Filogenia
10.
Virology ; 371(2): 350-61, 2008 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-17976679

RESUMO

We characterized tellina virus 1 (TV-1), a birnavirus isolated from the marine bivalve mollusk Tellina tenuis. Genome sequence analysis established that TV-1 is representative of a viral cluster distant from other birnaviruses. The maturation process of the polyprotein encoded by the genomic segment A was delineated with the identification of the N-termini of the viral protease VP4 and the ribonucleoprotein VP3, and the characterization of peptides deriving from the processing of pVP2, the VP2 capsid protein precursor. One of these peptides was shown to possess a membrane-disrupting domain. Like the blotched snakehead virus, the polyprotein exhibits a non-structural polypeptide (named [X]) located between pVP2 and VP4. Mutagenesis analysis allowed the identification in VP4 of a catalytic Ser-Lys dyad that does not possess the common Gly-X-Ser signature of the serine hydrolases. The genomic segment B encodes the viral RNA-dependent RNA-polymerase VP1 with the unique sequence motif arrangement identified in other birnavirus VP1s.


Assuntos
Aquabirnavirus/classificação , Birnaviridae/classificação , Bivalves/virologia , Genoma Viral , Poliproteínas , Análise de Sequência de DNA , Sequência de Aminoácidos , Animais , Aquabirnavirus/química , Aquabirnavirus/genética , Aquabirnavirus/metabolismo , Birnaviridae/genética , Linhagem Celular Tumoral , Clonagem Molecular , Modelos Moleculares , Dados de Sequência Molecular , Peptídeos/química , Peptídeos/genética , Peptídeos/metabolismo , Poliproteínas/química , Poliproteínas/genética , Poliproteínas/metabolismo , Serina Endopeptidases/metabolismo , Proteínas Virais/química , Proteínas Virais/genética , Proteínas Virais/metabolismo
11.
Microbiol Immunol ; 51(4): 397-406, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17446679

RESUMO

Yellowtail ascites virus (YTAV) is the causative agent of ascites and deformity in fish and causes serious losses to the fish-farming industry of yellowtail fry and fingerling Seriola quinqueradiata in Japan. In 2006, cultured yellowtail died from ascites in Kochi, Japan. We isolated and characterized a virus from the diseased fish. Based on the pathogenicity, culture characteristics, morphological features, RT-PCR results targeting VP2/NS region, phylogeny based on the VP1 amino acid sequence, and immunochemical reactivity of structural proteins, the virus isolate was identified as YTAV (designated as YTAV-06). YTAV-06 was a more virulent isolate than YTAV Y-6, isolated originally from yellowtail with ascites. To our knowledge, this is the first report describing that YTAV isolates may vary in their virulence.


Assuntos
Ascite/veterinária , Birnaviridae/patogenicidade , Virulência/genética , Animais , Ascite/virologia , Birnaviridae/classificação , Birnaviridae/genética , Birnaviridae/isolamento & purificação , Linhagem Celular , Doenças dos Peixes/virologia , Peixes , Filogenia
12.
Uirusu ; 55(1): 133-44, 2005 Jun.
Artigo em Japonês | MEDLINE | ID: mdl-16308540

RESUMO

Marine birnavirus (MABV) is a member of the genus Aquabirnavirus of the family Birnaviridae. MABV is an unenveloped icosahedral virus about 60 nm in diameter with two genomes of double-stranded RNA. MABV adsorbed not only onto the cell surfaces of susceptible (CHSE-214 and RSBK-2) cells but also onto resistant (FHM and EPC) cells. Furthermore, the virus entered into the cytoplasm through the endocytotic pathway in CHSE-214, RSBK-2 and FHM cells but did not penetrate EPC cells. The virus was found to bind to an around 250 kDa protein on CHSE-214, RSBK-2, FHM and EPC cells. The syntheses of viral proteins pVP2, NS and VP3 and further proteolytic processing after viral infection were examined by using Western blot analysis. pVP2, NS and VP3 were detected in the cytosolic fractions of CHSE-214, RSBK-2 and FHM cells at 4 h after infection. At this time, VP3 underwent further proteolytic processing in the cytosolic fractions of CHSE-214 and RSBK-2 cells. The expression of pVP2, NS and VP3 increased and pVP2 and NS also underwent further proteolytic processing similar to VP3 in the cytosolic fractions of CHSE-214, RSBK-2 and FHM cells at 8 h after infection. The further proteolytic processing of VP3 was detected in the nuclear fractions of CHSE-214, RSBK-2, but VP3 was detected as a single band in the nuclear fraction of FHM cells. pVP2 and NS were detected as thin bands only in the nuclear fractions of CHSE-214 cells. The results of Western blot analysis demonstrated that pVP2, NS and VP3 are localized in the nuclear fraction when they were independently expressed in CHSE-214, RSBK-2, FHM and EPC cells. The expression pattern in the cytosolic fraction was identical among the four cell lines when pVP2 and NS were independently expressed. However, pVP2 and NS were not detected in the nuclear fraction of CHSE-214 cells. Further proteolytic processing of VP3 was detected in both cytosolic and nuclear fractions of RSBK-2 ,FHM and EPC cells (Low level in EPC cell), but not in CHSE-214 cells when VP3 was independently expressed. Then, the processes of preVP2 to form morphological assemblages in the presence of VP3 or the cleavage of VP3 into two proteins in CHSE-214 cells were studied. When preVP2- and VP3 were co-expressed, virion like particles (64 nm, diameter) were observed close to the nuclear membrane by electron microscopy. The co-expression of preVP2 and the cleaved VP3 proteins led to an efficient assembly of tubules (22 nm, diameter). Further important finds will be obtained by this infection system using 4 fish cell lines in the next couple of years.


Assuntos
Birnaviridae/patogenicidade , Peixes/virologia , Animais , Birnaviridae/classificação , Birnaviridae/genética , Proteínas do Capsídeo/metabolismo , Proteínas do Capsídeo/fisiologia , Células Cultivadas , Endocitose , Receptores Virais/fisiologia , Serina Endopeptidases/fisiologia
13.
Arch Virol ; 148(4): 745-58, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12664297

RESUMO

The cDNA nucleotide sequence of the genome segment B encoding the VP1 protein, the putative RNA-dependent RNA polymerase (RdRp), was determined for 5 marine birnavirus (MABV) strains from different host or geographic origins and 1 infectious pancreatic necrosis virus (IPNV) strain AM-98. Segment B of the IPNV AM-98 strain and 4 MABV strains, Y-6, YT-01A, H1 and NC1, contained a 2535 bp ORF, which encoded a protein of 845 amino acid residues with a predicted MW of 94.4 kDa. Only the MABV AY-98 RdRp had 1 amino acid shorter RdRp. Pairwise comparisons were made among our data and 4 other known IPNV sequences. The nucleotide sequences of the 5 MABV strains were very similar each other, with identities of 98.3-99.7%. The highest divergence of the nucleotide level was between MABV strains and IPNV SP strain (serotype A2), with 20.4-20.8% divergences in the coding region, which gave 10.1-11.3% divergence in the amino acid level. The aquabirnavirus RdRp was noticeably conserved in amino acid sequences. Though the identities of the nucleotide sequences of encoding region were 85.1-85.9% between MABV strains and IPNV serotype A1 strains, they shared as high as 95.1-95.9% identities in amino acid level. A phylogenetic tree was constructed based on the amino acid sequences of the RdRp gene from different birnaviruses including avibirnavirus and entomobirnavirus. Ten aquabirnavirus strains were clustered into 3 Genogroups. The Genogroup I consisted of four IPNV A1 serotype strains. All MABV strains were clustered into Genogroup II. Only IPNV SP strain was clustered into an independent Genogroup III.


Assuntos
Birnaviridae/genética , Peixes/virologia , Genes Virais , RNA Replicase/genética , Sequência de Aminoácidos , Animais , Birnaviridae/classificação , Birnaviridae/enzimologia , Linguado/virologia , Vírus da Necrose Pancreática Infecciosa/enzimologia , Vírus da Necrose Pancreática Infecciosa/genética , Japão , Coreia (Geográfico) , Dados de Sequência Molecular , Peso Molecular , Oncorhynchus/virologia , Fases de Leitura Aberta , Osmeriformes/virologia , Perciformes/virologia , Filogenia , RNA Replicase/química , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico
14.
J Virol ; 77(1): 719-25, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12477876

RESUMO

By different approaches, we characterized the birnavirus blotched snakehead virus (BSNV). The sequence of genomic segment A revealed the presence of two open reading frames (ORFs): a large ORF with a 3,207-bp-long nucleotide sequence and a 417-nucleotide-long small ORF located within the N-terminal half of the large ORF, but in a different reading frame. The large ORF was found to encode a polyprotein cotranslationally processed by the viral protease VP4 to generate pVP2 (the VP2 precursor), a 71-amino-acid-long peptide ([X]), VP4, and VP3. The two cleavage sites at the [X]-VP4 and VP4-VP3 junctions were identified by N-terminal sequencing. We showed that the processing of pVP2 generated VP2 and several small peptides (amino acids [aa] 418 to 460, 461 to 467, 468 to 474, and 475 to 486). Two of these peptides (aa 418 to 460 and 475 to 486) were positively identified in the viral particles with 10 additional peptides derived from further processing of the peptide aa 418 to 460. The results suggest that VP4 cleaves multiple Pro-X-Ala downward arrow Ala motifs, with the notable exception of the VP4-VP3 junction. Replacement of the members of the predicted VP4 catalytic dyad (Ser-692 and Lys-729) confirmed their indispensability in the polyprotein processing. The genomic segment B sequence revealed a single large ORF encoding a putative polymerase, VP1. Our results demonstrate that BSNV should be considered a new aquatic birnavirus species, slightly more related to IBDV than to IPNV.


Assuntos
Aquabirnavirus/classificação , Avibirnavirus/classificação , Birnaviridae/classificação , Sequência de Aminoácidos , Birnaviridae/química , Birnaviridae/genética , Proteínas do Capsídeo/química , Proteínas do Capsídeo/metabolismo , Clonagem Molecular , Genoma Viral , Dados de Sequência Molecular , Filogenia , Vírion/química
15.
Dis Aquat Organ ; 38(2): 87-91, 1999 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-10598281

RESUMO

A birnavirus was recently isolated from cultured ayu Plecoglossus altivelis on Shikoku island, Japan. The diseased fish displayed vertebral or vertical curvature and mild haemorrhage around the brain. Cytopathic effects (CPE) of the virus, including cell roundness, filamentous change and cell lysis, were observed in CHSE-214, RTG-2 and RSBK-2 cells. The virus isolated from ayu, designated the AY-98 strain, was found to be antigenically related to the marine birnavirus (MABV) Y-6 strain that originated from yellowtail Seriola quinqueradiata. AY-98 had a bi-segmented RNA genome and the same nucleotide sequence in the 310 bp VP2/NS junction as MABV Y-6. At the same time that the ayu epizootics occurred, another birnavirus (AM-98) was isolated from amago salmon Oncorhynchus rhodurus which were cultured 66 km away from the ayu farm. AM-98 showed a similar CPE and had the same host cell ranges as AY-98. However, AM-98 was serologically similar to the VR-299 strain of infectious pancreatic necrosis virus (IPNV) and their nucleotide sequences in the VP2/NS junction region showed 98% homology without changes at the amino acid level. In this study, the ayu strain AY-98 was grouped into MABV, whereas the amago salmon strain AM-98 was grouped into IPNV. This indicates that the 2 birnaviruses originated from different sources in spite of the fact that the places where they were isolated are close to one another. The results in this paper show a new aspect of the traditional consensus that the same serogroup of birnavirus distribute in close geographic areas.


Assuntos
Infecções por Birnaviridae/veterinária , Birnaviridae/isolamento & purificação , Doenças dos Peixes/virologia , Salmão , Animais , Antígenos Virais/análise , Aquicultura , Sequência de Bases , Birnaviridae/classificação , Birnaviridae/genética , Birnaviridae/imunologia , Infecções por Birnaviridae/virologia , Eletroforese em Gel de Ágar , Peixes , Japão , Rim/virologia , Dados de Sequência Molecular , Testes de Neutralização/veterinária , RNA Viral/química , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Alinhamento de Sequência , Homologia de Sequência do Ácido Nucleico , Vírion/genética
16.
Microbiologia ; 13(2): 149-60, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9253755

RESUMO

The number of viruses isolated from fish has grown in the last few years as a reflection of the increasing interest in fish diseases, particularly those occurring in aquaculture facilities. Of all the described viruses, only a few are considered to be of serious concern and economic importance; they are described in this review, drawing special attention to the four families of viruses (Birnaviridae, Rhabdoviridae, Iridoviridae and Reoviridae) that have been reported in Spanish aquaculture. Infectious pancreatic necrosis virus, a member of the first family, is the most spread virus with a prevalence of 39%. Viral diseases are untreatable and because effective and safe vaccines for fish are not yet commercially available, a great care needs to be exercised when moving fish or eggs from one site or country to another. Some fish health control regulations have been legislated in Europe and USA.


Assuntos
Aquicultura , Doenças dos Peixes/virologia , Peixes/virologia , Viroses/veterinária , Animais , Aquicultura/legislação & jurisprudência , Birnaviridae/classificação , Birnaviridae/isolamento & purificação , Birnaviridae/ultraestrutura , Infecções por Birnaviridae/epidemiologia , Infecções por Birnaviridae/veterinária , Doenças dos Peixes/epidemiologia , Iridoviridae/isolamento & purificação , Iridoviridae/ultraestrutura , Reoviridae/classificação , Reoviridae/isolamento & purificação , Reoviridae/ultraestrutura , Infecções por Reoviridae/epidemiologia , Infecções por Reoviridae/veterinária , Rhabdoviridae/isolamento & purificação , Rhabdoviridae/ultraestrutura , Infecções por Rhabdoviridae/epidemiologia , Infecções por Rhabdoviridae/veterinária , Salmão/virologia , Espanha/epidemiologia , Truta/virologia , Viroses/epidemiologia , Viroses/virologia
17.
Appl Environ Microbiol ; 62(7): 2513-20, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8779591

RESUMO

Aquatic birnaviruses are the most ubiquitous and diverse group of viruses in the family Birnaviridae. Several cause different diseases in a variety of fish species, such as infectious pancreatic necrosis virus in salmonids in North America, Europe, and Asia and European eel virus in eel in Asia. Most isolates are antigenically related and belong to a single serogroup (serogroup A) comprising nine serotypes. Previous studies with monoclonal antibodies have demonstrated considerable variation in epitope profiles even among strains within a single serotype. The few studies of genomic variation among these viruses, which have focused on the NS/VP3 coding region, demonstrated the existence of several genogroups that generally did not correlate with antigenic groups. In this study, PCR was used to amplify a 1,180-bp cDNA genomic fragment representing most of the VP2 (the major outer capsid protein) coding region from five serotype A type strains and 17 Asian isolates. The PCR products were digested with nine different restriction enzymes. Restriction fragment length polymorphism profiles demonstrated heterogeneity among the tested viruses; however, the isolates from Asia were closely related to each other. Cluster analysis of the restriction fragment length polymorphism patterns demonstrated that these viruses could be divided into four major genogroups. In contrast to previous studies of variation in the NS/VP3 coding region, these genogroups based on variation in the VP2 coding region correlated with a serological classification based on VP2-specific monoclonal antibody reaction patterns. Furthermore, all Asian isolates tested belonged to one genogroup typified by the serotype type strain Ab.


Assuntos
Birnaviridae/genética , Variação Genética , Genoma Viral , Microbiologia da Água , Animais , Anticorpos Monoclonais , Sequência de Bases , Birnaviridae/classificação , Birnaviridae/isolamento & purificação , Primers do DNA/genética , DNA Viral/genética , Peixes , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Sorotipagem
19.
Can J Microbiol ; 42(1): 93-7, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8595603

RESUMO

Previous analysis of the two serotypes of infectious bursal disease virus (IBDV) have demonstrated the correlation between antigenicity and similarities of nucleotide and amino acid sequences of the VP2 coding region in genome segment A. Restriction fragment profiles of genomic segment A cDNA of five IBDV isolates (QC-2 and QT-1 of serotype 1, SK9, and Nos. 39 and 52 of serotype 2) were determined in order to establish the genetic relationship of these viruses to other avibirnaviruses. The restriction fragment profiles using three of seven restriction enzymes (SacI which cuts in the VP2 region, DraIII which cuts in the VP3 region, and EcoRI which cuts in the VP4 region) were used to place QC-2, QT-1, SK9, No. 39, and No. 52 within the phylogenetic tree among seven other avibirnaviruses of known sequence. The two IBDV serotypes corresponded to two genotypes on the basis of the presence or absence of the SacI restriction site. The serotype 1 cluster of strains was further differentiated into five minor clusters on the basis of the PstI, EcoRI, BamHI, HindIII, DraIII, and Bsu361 restriction sites, which emphasized the geographical origins of the strains. It is concluded that restriction analysis of cDNA of the whole viral genomic segment A allows differentiation of IBDV isolates on the basis of their antigenicity and geographical origin.


Assuntos
Birnaviridae/genética , Vírus da Doença Infecciosa da Bursa/genética , RNA Viral/genética , Austrália , Sequência de Bases , Birnaviridae/classificação , DNA Complementar/genética , Europa (Continente) , Evolução Molecular , Vírus da Doença Infecciosa da Bursa/classificação , Dados de Sequência Molecular , América do Norte , Filogenia , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Sorotipagem
20.
Appl Environ Microbiol ; 61(8): 2925-9, 1995 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7487025

RESUMO

The current classification of aquatic birnaviruses is based on seroneutralization assays with polyclonal antibodies. In this study a comparison of several procedures used for serotyping aquatic birnaviruses was made with 10 virus strains (4 reference strains from salmonids and 6 birnaviruses isolated from turbot [Scophthalmus maximus]). The relationships among the birnavirus strains were studied by seroneutralization assay with polyclonal antibodies and by immunodot assay with both polyclonal and monoclonal antibodies. The results were compared with a presumptive classification obtained from analysis of restriction enzyme patterns of cDNA products obtained by PCR amplification. No correlation was found among the results obtained by the different procedures. The seroneutralization and the immunodot assays with polyclonal antibodies were not useful in classifying these birnaviruses strains; however, patterns of reaction with monoclonal antibodies emphasized the individuality of the strains, particularly in the case of two strains (231 and 460) whose patterns did not correspond to established serotypes. The application of PCR and restriction enzyme analysis is a promising system for approaching the classification of this viral group on the basis of genomic differences and similarities. The variable results obtained in this comparison lead us to think that the current classification of aquatic birnavirus may not be the most accurate and there is a need for modification incorporating recent isolates, not only from salmonid species but also from marine fish.


Assuntos
Birnaviridae/classificação , Sorotipagem/métodos , Animais , Anticorpos Monoclonais , Anticorpos Antivirais , Sequência de Bases , Birnaviridae/genética , Birnaviridae/isolamento & purificação , Primers do DNA/genética , DNA Viral/genética , Linguados/microbiologia , Dados de Sequência Molecular , Testes de Neutralização , Salmonidae/microbiologia
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