RESUMO
Rotavirus strains belonging to G types 1 to 4 and having a P3 genotype (M37-like VP4) were recovered from children with symptomatic and asymptomatic infections. Partial sequences of their VP4 genes were determined in an attempt to characterize these strains further. The genomic regions encoding VP8*, the connecting and putative fusion peptides and three other regions in VP5* were sequenced. The deduced amino acid sequences were compared with rotavirus strains belonging to different P genotypes that had been previously reported. High degrees of identity were found between the VP8* fragment of all human P3 strains (92.7 to 99.7%) suggesting that they belong to the same genotype, regardless of differences in their virulence. Furthermore, based on comparative sequence analysis, we did not identify any amino acid(s) that differ appreciably between symptomatic and asymptomatic strains and could therefore be associated with virulence. The results suggest that the P3 genotype, although frequently associated with asymptomatic infections, may not be the single determining factor in attenuation of symptoms.
Assuntos
Capsídeo/genética , Genes Virais/genética , Infecções por Rotavirus/microbiologia , Rotavirus/genética , Proteínas Estruturais Virais/genética , Sequência de Aminoácidos , Sequência de Bases , Brasil , Capsídeo/química , Proteínas do Capsídeo , Pré-Escolar , Infecção Hospitalar , Diarreia/microbiologia , Genótipo , Humanos , Lactente , Recém-Nascido , Dados de Sequência Molecular , Paris , Rotavirus/classificação , Rotavirus/patogenicidade , Homologia de Sequência de Aminoácidos , Estados Unidos , VirulênciaRESUMO
The dot ELISA technique was applied for direct detection of BK virus in clinical urine samples. The assay was performed on nitrocellulose paper dotted with the polyethylene glycol precipitated urine samples free of cellular debris. BK virus was detected with an anti-BK virus monoclonal antibody, and the complex was visualized by immunoperoxidase staining. Positive reaction appeared as well-defined dark blue spots. Of the 110 urine samples examined, 31 were positive in the dot ELISA and 79 proved negative. Comparing with the IIF results, the dot ELISA had a 88.46% of sensibility and 90.4% of specificity, and the results agreed completely in 99 samples. The simple dot ELISA technique can be recommended for detection of BK virus excretion in routinary diagnostic.