RESUMO
The goal of this study was to test the feasibility of BALB/c mice as an experimental model in the study of dengue disease. BALB/c mice were intraperitoneal infected with DENV-2 obtained from a human patient. Histopathological analysis of infected animals revealed liver injury with viral antigens detection. In initial stages, the most prominent lesions were vacuolization and diffuse steatosis in hepatocytes. Serum levels of ALT and AST increased progressively, reaching the highest values 7 days p.i. and decreasing at the 14th day. Since levels of circulating virus were very low, viremia was analyzed in C6/36 cells. Virus presence was detected by ultrastructural analysis, confirmed by RT-PCR assays. Period of viremia was analyzed by flow cytometry with cells incubated with mouse-infected sera collected in different days, revealing peak virus levels at the 7th day p.i. All such data correlate to the development of the disease described in humans.
Assuntos
Vírus da Dengue/genética , Vírus da Dengue/patogenicidade , Dengue/patologia , Genoma Viral , Fígado/patologia , Animais , Antígenos Virais/isolamento & purificação , Sequência de Bases , Linhagem Celular , Primers do DNA , Dengue/virologia , Vírus da Dengue/isolamento & purificação , Modelos Animais de Doenças , Humanos , Fígado/ultraestrutura , Fígado/virologia , Camundongos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Vacúolos/patologia , Vacúolos/virologiaRESUMO
Dengue virus replication in mosquito cell cultures was observed by electron microscopy in one fatal and 40 classical isolates from a dengue type 2 outbreak in Rio de Janeiro and compared with the prototype New Guinea C strain. All the Brazilian isolates presented, beside the classical structured dengue virus particles, fuzzy coated virus-like particles, never observed in the referencial New Guinea C virus strain. More numerous DEN-2 virus particles, fuzzy coated virus-like particles, defective virus particles and smooth membrane structures inside the rough endoplasmic reticulum characterized the unique fatal isolate examined.