RESUMO
In Argentina, classical vaccines are used to control infectious bursal disease virus (IBDV); however, outbreaks of IBDV are frequently observed. This could be due to failures in the vaccination programs or to the emergence of new strains, which would be able to break through the protection given by vaccines. Hence, genetic characterization of the viruses responsible for the outbreaks that occurred in recent years is crucial for the evaluation of the control programs and the understanding of the epidemiology and evolution of IBDV. In this study, we characterized 51 field samples collected in Argentina (previously identified as IBDV positive) through the analysis of previously identified apomorphic sequences. Phylogenetic analysis of regVP2 showed that 42 samples formed a unique cluster (Argentinean lineage), seven samples were typical classical strains (one of them was a vaccine strain), and two belonged to the very virulent lineage (vvIBDV). Interestingly, when the analysis was performed on the regVP1 sequences, the field samples segregated similarly to regVP2; thus, we observed no evidence of a reassortment event in the Argentinean samples. Amino acid sequence analysis of regVP2 showed a particular pattern of residues in the Argentinean lineage, particularly the presence of T272, P289 and F296, which had not been reported before as signature sequences for any IBDV phenotype. Notably, the residue S254, characteristic of the antigenic variant, was not present in any of the Argentinean samples.
Assuntos
Infecções por Birnaviridae/veterinária , Vírus da Doença Infecciosa da Bursa/genética , Vírus da Doença Infecciosa da Bursa/isolamento & purificação , Doenças das Aves Domésticas/virologia , Sequência de Aminoácidos , Animais , Argentina/epidemiologia , Infecções por Birnaviridae/epidemiologia , Infecções por Birnaviridae/virologia , Galinhas , Surtos de Doenças , Vírus da Doença Infecciosa da Bursa/química , Vírus da Doença Infecciosa da Bursa/classificação , Dados de Sequência Molecular , Filogenia , Doenças das Aves Domésticas/epidemiologia , Alinhamento de Sequência , Proteínas Estruturais Virais/química , Proteínas Estruturais Virais/genética , VirulênciaRESUMO
Epinotia aporema granulovirus (EpapGV) has attracted interest as a potential biocontrol agent of the soybean pest Epinotia aporema in Argentina. Studies on virus/host interactions conducted so far have lacked an accurate method to assess the progress of virus load during the infection process. The present paper reports the development of a real-time PCR for EpapGV and its application to describe viral kinetics following ingestion of two different virus doses by last-instar E. aporema larvae. Real-time PCR was shown to be a reliable method to detect and quantify the presence of EpapGV in the analyzed samples. The increase in virus titer (log) exhibited a sigmoidal pattern, with an exponential growth phase between 24 and 48 h postinfection for both initial doses tested.
Assuntos
Baculoviridae/isolamento & purificação , Lepidópteros/virologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Animais , Baculoviridae/química , Baculoviridae/classificação , Baculoviridae/genética , Cinética , Proteínas Virais/química , Proteínas Virais/genéticaRESUMO
Argentina suffered an extensive foot-and-mouth disease (FMD) epidemic between July 2000 and January 2002, 3 months after obtaining the official FMD-free without vaccination status conferred by the World Organization for Animal Health. This is one of the largest FMD epidemics controlled by implementation of a systematic mass vaccination campaign in an FMD-free country. In 2000, 124 herds were reported as FMD positive, 2394 herds in 2001 and one in January 2002; the total number of cattle herds in the country at that time was approximately 230 000. Estimates of FMD transmission are important to understand the dynamics of disease spread and for estimating the value for the parameterization of disease transmission models, with the ultimate goals of predicting its spread, assessing and designing control strategies, conducting economic analyses and supporting the decision-making process. In this study, the within-herd coefficient of transmission, ß, was computed for herds affected in the 2001 FMD epidemic and categorized as low or high based on the median value of ß. A logistic regression model was fitted to identify factors significantly associated with high values of ß. Results suggested that the odds of having a high within-herd transmission were significantly associated with time from initial herd infection to disease detection, date of report, vaccination, and time from initial herd infection to herd vaccination. Results presented in this study demonstrate, in quantifiable terms, the protective impact of vaccination in reducing FMD transmission in infected herds. These results will be useful for the parameterization of epidemiological models aimed at quantifying the impact of vaccination and for the design and implementation of FMD emergency vaccination strategies in face of an epidemic.
Assuntos
Doenças dos Bovinos/transmissão , Surtos de Doenças/veterinária , Vírus da Febre Aftosa/classificação , Febre Aftosa/prevenção & controle , Vacinas Virais/imunologia , Animais , Argentina/epidemiologia , Bovinos , Doenças dos Bovinos/epidemiologia , Surtos de Doenças/prevenção & controle , Febre Aftosa/epidemiologia , Febre Aftosa/transmissão , Modelos Logísticos , Análise Multivariada , Sorotipagem , Fatores de TempoRESUMO
Chicken infectious anemia virus (CAV) is a worldwide-distributed infectious agent that affects commercial poultry. Although this agent was first detected in Argentina in 1994, no further studies on CAV in this country were reported after that. The recent increased occurrence of clinical cases of immunosuppression that could be caused by CAV has prompted this study. Our results confirmed that CAV is still circulating in commercial flocks in Argentina. Phylogenetic analysis focusing on the VP1 nucleotide sequence showed that all Argentinean isolates grouped together in a cluster, sharing a high similarity (> 97%) with genotype B reference strains. However, Argentinean isolates were distantly related to other strains commonly used for vaccination in this country, such as Del-Ros and Cux-1. Sequence analysis of predicted VP1 peptides showed that most of the Argentinean isolates have a glutamine residue at positions 139 and 144, suggesting that these isolates might have a reduced spread in cell culture compared with Cux-1. In addition, a particular amino acid substitution at position 290 is present in all studied Argentinean isolates, as well as in several VP1 sequences from Malaysia, Australia, and Japan isolates. Our results indicate that it is possible to typify CAV strains by comparison of VPI nucleotide sequences alone because the same tree topology was obtained when using the whole genome sequence. The molecular analysis of native strains sheds light into the epidemiology of CAV in Argentinean flocks. In addition, this analysis could be considered in future control strategies focused not only on breeders but on broilers and layer flocks.
Assuntos
Vírus da Anemia da Galinha/genética , Galinhas , Infecções por Circoviridae/veterinária , Doenças das Aves Domésticas/virologia , Sequência de Aminoácidos , Animais , Argentina/epidemiologia , Sequência de Bases , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/metabolismo , Infecções por Circoviridae/epidemiologia , Infecções por Circoviridae/virologia , Regulação Viral da Expressão Gênica , Epidemiologia Molecular , Filogenia , Doenças das Aves Domésticas/epidemiologiaRESUMO
Bovine viral diarrhoea virus (BVDV) is a pestivirus that infects mainly bovine cattle. Nevertheless, there are several reports about infections in other members of the Artiodactyla order including serological studies, that indicate infection of BVDV in buffaloes. The aim of this article is to study the presence of BVDV in three young water buffaloes, displaying nonspecific clinical signs, compatible with the BVDV infection. Both immunohistochemistry and RT-PCR confirmed the presence of BVDV in the animals. The sequence analysis on RT-PCR amplicons revealed high identity with reference strains of genotypes 1a and 1b. Although BVDV was unequivocally identified in the sick animals, it has not been proved it is responsible for the clinical signs. Further studies are needed to clarify the pathogenic role of BVDV infection in this animal species, and the role of buffaloes in the epidemiology of BVDV infection.
Assuntos
Antígenos Virais/isolamento & purificação , Búfalos/virologia , Vírus da Diarreia Viral Bovina/isolamento & purificação , Ácidos Nucleicos/isolamento & purificação , Infecções por Pestivirus/veterinária , Animais , Vesícula Biliar/virologia , Íleo/virologia , Imuno-Histoquímica/veterinária , Infecções por Pestivirus/virologia , FilogeniaRESUMO
During 2000-2002 a foot-and-mouth disease (FMD) epizootic affected Argentina and spread across the country resulting in more than 2500 outbreaks. In order to study the evolution of the FMD viruses (FMDV) and help with disease control measures, a genetic characterization and phylogenetic analysis was performed of 43 field isolates representative of the epizootic. The nucleotide sequence of the VP1-coding region was determined for the viruses and used in this study. Two serotype A lineages, A/Arg/00 and A/Arg/01 (1000/1000 bootstrap value) and two different serotype O/Arg/00 lineages (848/1000 bootstrap value) were identified. Phylogenetic analysis showed that viruses A/Arg/01 and O/Arg/00 could be related with former South American isolates, while the origin of A Argentina 2000 viruses remains unclear. Comparison of the amino acid sequences with vaccine reference strains revealed differences at critical antigenic sites for emergent strains A/Arg/00 and A/Arg/01, leading to a change in the current vaccine formulation.
Assuntos
Proteínas do Capsídeo/genética , Vírus da Febre Aftosa/genética , Febre Aftosa/epidemiologia , Sequência de Aminoácidos , Animais , Argentina/epidemiologia , Sequência de Bases , Proteínas do Capsídeo/química , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/virologia , Surtos de Doenças/veterinária , Febre Aftosa/virologia , Vírus da Febre Aftosa/classificação , Epidemiologia Molecular , Dados de Sequência Molecular , Filogenia , RNA Viral/química , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Alinhamento de Sequência/veterinária , Homologia de Sequência do Ácido Nucleico , Sorotipagem/veterináriaRESUMO
The complete nucleotide sequence of foot-and-mouth disease virus (FMDV) South American strain O(1) Campos/Bra/58 was determined. The 8,168 Kb sequence and the deduced amino acid sequence were compared to published FMDV sequences. They showed the highest sequence homology with the O(1) Kaufbeuren/FRG/66 strain, but closer evolutionary relatedness to the Argentinean strains.
Assuntos
Vírus da Febre Aftosa/genética , RNA Viral/química , Sequência de Aminoácidos , Sequência de Bases , Proteínas do Capsídeo/química , Vírus da Febre Aftosa/classificação , Dados de Sequência Molecular , Filogenia , Alinhamento de Sequência , Homologia de Sequência de AminoácidosRESUMO
We have analysed complete or partial VPI sequences of 31 foot-and-mouth disease (FMD) viruses belonging to serotypes A, O and C to determine the genetic relatedness of field strains of FMD virus (FMDV) that have circulated in Argentina between 1961 and 1994. Phylogenetic analysis, which also included 15 previously published Argentinean sequences and six reference strains, revealed that (i) FMD type A strains showed the highest genetic heterogeneity and could be divided into five lineages with a sequence divergence of 0.9-18.5% between strains (ii) most of the FMD type O viruses grouped in two clusters (within cluster sequence divergence ranging from 0.2% to 6.0%) circulating in Argentina since the early 1960s, and (iii) FMD type C viruses were grouped in two clusters with a 13.4% nucleotide sequence divergence between each cluster. The availability of sequence data for many more field isolates from the region will enable us to understand the genetic relationships between FMDV strains and to rapidly trace the source of an FMD outbreak for epidemiological surveillance.
Assuntos
Vírus da Febre Aftosa/classificação , Argentina/epidemiologia , Vírus da Febre Aftosa/genética , Epidemiologia Molecular , Filogenia , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Nucleotide sequence and phylogenetic analysis of the VP1 structural protein have been used extensively as diagnostic and epidemiological tools for foot and mouth disease virus (FMDV). In this report we have applied this methodology to the analysis of the VP1 coding sequence from FMDV strains isolated in Argentina during 1993-1994. The results demonstrated that the field isolates were related to the vaccine strains used at that time. However the involvement of the vaccine virus appeared to be different for outbreaks caused by FMD viruses type O or C. These data provide a database essential for determining the origin of new epizootics.
Assuntos
Aphthovirus/isolamento & purificação , Capsídeo/genética , Doenças dos Bovinos/virologia , Febre Aftosa/virologia , Animais , Antígenos Virais/genética , Antígenos Virais/imunologia , Aphthovirus/classificação , Aphthovirus/genética , Aphthovirus/imunologia , Argentina/epidemiologia , Sequência de Bases , Proteínas do Capsídeo , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/transmissão , Surtos de Doenças , Febre Aftosa/epidemiologia , Febre Aftosa/transmissão , Dados de Sequência Molecular , Filogenia , RNA Viral/genética , Estudos Retrospectivos , Alinhamento de Sequência , Homologia de Sequência do Ácido Nucleico , Sorotipagem , Vacinas Virais/efeitos adversosRESUMO
The BVDV glycoproteins gp48 and gp53 were expressed in the baculovirus eukaryotic system. Both recombinant proteins were recognized in western blot analysis by monoclonal antibodies and polyclonal serum. Immunofluorescent test demonstrated that gp53 was localized on the cell surface whereas gp48 was in the cytoplasm. The expressed proteins were extracted by non-denaturing detergent treatment. Rabbit antiserum raised against gp53 recombinant protein efficiently neutralized the virus. These results demonstrate that the recombinant proteins have immunological properties similar to those of the native viral protein and that they can be useful as diagnostic reagents.
Assuntos
Vírus da Diarreia Viral Bovina/química , Proteínas do Envelope Viral/isolamento & purificação , Animais , Western Blotting , Bovinos , Linhagem Celular , Vírus da Diarreia Viral Bovina/genética , Vírus da Diarreia Viral Bovina/imunologia , Vetores Genéticos/genética , Soros Imunes , Rim/citologia , Masculino , Nucleopoliedrovírus/genética , Coelhos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Proteínas Recombinantes de Fusão/isolamento & purificação , Spodoptera/citologia , Testículo/citologia , Transfecção , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/imunologiaRESUMO
Nucleotide sequence and phylogenetic analysis of the VP1 structural protein have been used extensively as diagnostic and epidemiological tools for foot and mouth disease virus (FMDV). In this report we have applied this methodology to the analysis of the VP1 coding sequence from FMDV strains isolated in Argentina during 1993-1994. The results demonstrated that the field isolates were related to the vaccine strains used at that time. However the involvement of the vaccine virus appeared to be different for outbreaks caused by FMD viruses type O or C. These data provide a database essential for determining the origin of new epizootics.(AU)
Assuntos
Estudo Comparativo , Animais , Bovinos , RESEARCH SUPPORT, NON-U.S. GOVT , Aphthovirus/isolamento & purificação , Doenças dos Bovinos/virologia , Febre Aftosa/virologia , Antígenos Virais/genética , Antígenos Virais/imunologia , Aphthovirus/classificação , Aphthovirus/genética , Aphthovirus/imunologia , Argentina/epidemiologia , Sequência de Bases , Proteínas do Capsídeo , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/transmissão , Surtos de Doenças , Febre Aftosa/epidemiologia , Febre Aftosa/transmissão , Dados de Sequência Molecular , Filogenia , RNA Viral/genética , Estudos Retrospectivos , Alinhamento de Sequência , Homologia de Sequência do Ácido Nucleico , Sorotipagem , Vacinas Virais/efeitos adversosRESUMO
Nucleotide sequence and phylogenetic analysis of the VP1 structural protein have been used extensively as diagnostic and epidemiological tools for foot and mouth disease virus (FMDV). In this report we have applied this methodology to the analysis of the VP1 coding sequence from FMDV strains isolated in Argentina during 1993-1994. The results demonstrated that the field isolates were related to the vaccine strains used at that time. However the involvement of the vaccine virus appeared to be different for outbreaks caused by FMD viruses type O or C. These data provide a database essential for determining the origin of new epizootics.
Assuntos
Animais , Bovinos , Aphthovirus , Doenças dos Bovinos/virologia , Febre Aftosa , Antígenos Virais/genética , Antígenos Virais/imunologia , Aphthovirus , Argentina , Sequência de Bases , Proteínas do Capsídeo , Surtos de Doenças , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/transmissão , Febre Aftosa , Dados de Sequência Molecular , Filogenia , Estudos Retrospectivos , RNA Viral , Alinhamento de Sequência , Homologia de Sequência do Ácido Nucleico , Sorotipagem , Vacinas ViraisRESUMO
The BVDV glycoproteins gp48 and gp53 were expressed in the baculovirus eukaryotic system. Both recombinant proteins were recognized in western blot analysis by monoclonal antibodies and polyclonal serum. Immunofluorescent test demonstrated that gp53 was localized on the cell surface whereas gp48 was in the cytoplasm. The expressed proteins were extracted by non-denaturing detergent treatment. Rabbit antiserum raised against gp53 recombinant protein efficiently neutralized the virus. These results demonstrate that the recombinant proteins have immunological properties similar to those of the native viral protein and that they can be useful as diagnostic reagents.(AU)
Assuntos
Animais , Bovinos , Masculino , Coelhos , RESEARCH SUPPORT, NON-U.S. GOVT , Vírus da Diarreia Viral Bovina/química , Proteínas do Envelope Viral/isolamento & purificação , Western Blotting , Linhagem Celular , Vírus da Diarreia Viral Bovina/genética , Vírus da Diarreia Viral Bovina/imunologia , Vetores Genéticos/genética , Soros Imunes , Rim/citologia , Nucleopoliedrovírus/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Proteínas Recombinantes de Fusão/isolamento & purificação , Spodoptera/citologia , Testículo/citologia , Transfecção , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/imunologiaRESUMO
The BVDV glycoproteins gp48 and gp53 were expressed in the baculovirus eukaryotic system. Both recombinant proteins were recognized in western blot analysis by monoclonal antibodies and polyclonal serum. Immunofluorescent test demonstrated that gp53 was localized on the cell surface whereas gp48 was in the cytoplasm. The expressed proteins were extracted by non-denaturing detergent treatment. Rabbit antiserum raised against gp53 recombinant protein efficiently neutralized the virus. These results demonstrate that the recombinant proteins have immunological properties similar to those of the native viral protein and that they can be useful as diagnostic reagents.