RESUMO
PCR amplification with sequence-specific primers was used to detect canine parvovirus (CPV) DNA in 38 rectal swabs from Argentine domestic dogs with symptoms compatible with parvovirus disease. Twenty-seven out of 38 samples analyzed were CPV positive. The classical CPV2 strain was not detected in any of the samples, but nine samples were identified as CPV2a variant and 18 samples as CPV2b variant. Further sequence analysis revealed a mutation at amino acid 426 of the VP2 gene (Asp426Glu), characteristic of the CPV2c variant, in 14 out of 18 of the samples identified initially by PCR as CPV2b. The appearance of CPV2c variant in Argentina might be dated at least to the year 2003. Three different pathogenic CPV variants circulating currently in the Argentine domestic dog population were identified, with CPV2c being the only variant affecting vaccinated and unvaccinated dogs during the year 2008.
Assuntos
Doenças do Cão/epidemiologia , Doenças do Cão/virologia , Infecções por Parvoviridae/veterinária , Parvovirus Canino/classificação , Parvovirus Canino/genética , Sequência de Aminoácidos , Animais , Argentina/epidemiologia , Doenças do Cão/imunologia , Cães , Feminino , Masculino , Epidemiologia Molecular , Dados de Sequência Molecular , Mutação de Sentido Incorreto , Infecções por Parvoviridae/epidemiologia , Infecções por Parvoviridae/imunologia , Infecções por Parvoviridae/virologia , Parvovirus Canino/isolamento & purificação , Reação em Cadeia da Polimerase , Reto/virologia , Alinhamento de Sequência , Análise de Sequência de DNA , Proteínas Estruturais Virais/genética , Vacinas Virais/imunologiaRESUMO
RT-PCR was used to detect canine distemper virus (CDV) RNA in clotted blood from Argentine domestic dogs. The NP gene was detected in 73 out of 99 blood samples analyzed. The deduced amino acid sequence of these gene fragments showed 100% identity with the sequence of other wild-type and vaccine strains. A fragment of the hemagglutinin gene was amplified from 24 (32.9%) of the NP-RNA-positive clinical specimens. These H fragments were further analyzed by restriction fragment length polymorphism (RFLP) and sequencing. A single NdeI site was detected in all 24 wild-type strains but was absent in the vaccine strains. Phylogenetic analysis of the partial hemagglutinin amino acid sequences showed close clustering for local strains, clearly distinct from vaccine strains and other wild-type foreign CDV strains. One of the local strains, Arg 23, branched out of the root of the Argentine clade, close to the European strains, suggesting that two different pathogenic CDV genotypes are currently circulating in Argentina, one of them clearly predominant.
Assuntos
Vírus da Cinomose Canina/genética , Vírus da Cinomose Canina/isolamento & purificação , Cinomose/virologia , Sequência de Aminoácidos , Animais , Argentina , Sequência de Bases , Cães , Feminino , Hemaglutininas Virais/química , Hemaglutininas Virais/genética , Masculino , Dados de Sequência Molecular , Filogenia , Polimorfismo de Fragmento de Restrição , RNA Bacteriano/química , RNA Bacteriano/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Alinhamento de SequênciaRESUMO
Infectious bursal disease (IBD) viruses detected in commercial flocks of different regions of Argentina were analyzed by reverse transcription-polymerase chain reaction-restriction fragment length polymorphism (RFLP) of a VP2 gene fragment, followed by sequence analysis. Two out of eight IBD viruses presented an SspI restriction site, typical of the very virulent phenotype. Three IBD viruses presented a SacI restriction site, typical of classic virulent strains, and one isolate presented restriction sites for both enzymes. The Argentine IBD viruses showed three different molecular patterns by RFLP with the restriction endonuclease BstNI and five different patterns with MboI. By comparison of nucleotide and deduced amino acid sequences of the hypervariable region of the VP2 protein, four Argentine viruses were found to be closely related to Brazilian subclinical strains and two isolates were found to be related to vaccine IBDV strains in use in Argentina. Strain LD9569 was genetically characterized as a very virulent strain and was found to be closely related to international and regional vvIBDV strains. This is the first report on variability of IBDV strains circulating in Argentina.
